Soft Tissue - Central Florida Academy of Veterinary Medicine

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Central Florida Academy of Veterinary Medicine
Surgery – Soft Tissue | May 30 – 31 2015
Dr Howard Seim DACVS
Surgical Management of Abdominal Trauma
Howard B. Seim III, DVM, DACVS
Colorado State University
OVERVIEW
Patients that sustain a traumatic injury severe enough to cause an abdominal hernia or
patients that sustain penetrating abdominal wounds (i.e., gunshot, bite wounds) should have
an exploratory laparotomy. After a review of general principles and techniques of abdominal
surgery in cats and dogs, including the surgical techniques for ventral midline celiotomy,
abdominal exploration, abdominal wall closure, and management of complications such as
wound dehiscence, these proceedings outline the surgical management of traumatic
abdominal wall hernias and peritonitis. Step by step descriptions of the surgical technique for
repair of abdominal hernias are provided. For peritonitis, we will cover the indications and
techniques for abdomniocentesis, exploratory surgery, diagnostic abdominal lavage, and
open abdominal drainage. In the lecture, case examples admitted to the author’s critical care
service will be used to illustrate the surgeons' decision making techniques. Video of clinical
case material will be used to illustrate all techniques.
If you would like a copy of the video of this surgical procedure on DVD go to
www.videovet.org.
KEY FACTS
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The abdomen generally is explored by means of a ventral midline incision from xyphoid to
pubis. In most animals the entire abdomen, including the inguinal areas and the caudal
thorax, should be prepared for aseptic surgery to allow extension of the incision into the
thoracic or pelvic cavities if necessary.
Various techniques can be used to systematically explore the entire abdomen; every
surgeon should develop a consistent pattern to ensure that the entire abdominal cavity
and all structures are visualized and/or palpated in each animal.
Complications of abdominal surgery, including dehiscence (incisional hernias), may occur
if improper surgical technique is used. The most common cause of wound dehiscence in
the early postoperative period results from the surgeon’s inability to recognize the rectus
sheath or not getting adequate bites in the collagen dense rectus sheath.
patients that sustain penetrating abdominal wounds (i.e., gunshot, bite wounds) should
have a xyphoid to pubis abdominal exploratory laparotomy.
For most abdominal hernias, perform a ventral midline abdominal incision to allow the
entire abdomen to be explored. Assess the extent of visceral herniation. Reduce the
herniated contents and amputate or excise necrotic or devitalized tissue around the
hernia. Close the muscle layers of the hernia with simple interrupted or simple continuous
sutures.
Abdominocentesis— the percutaneous removal of fluid from the abdominal cavity—
usually is done for diagnostic purposes although it may occasionally be therapeutic.
Indications include shock without apparent cause, undiagnosed disease with signs
involving the abdominal cavity, suspicion of postoperative gastrointestinal dehiscence,
blunt or penetrating abdominal injuries (i.e., gunshot wounds, dog bites, vehicular injury),
and undiagnosed abdominal pain.
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Exploratory surgery is indicated when the cause of peritonitis cannot be determined or
when bowel rupture, intestinal obstruction (e.g., bowel incarceration, neoplasia), or
mesenteric avulsion is suspected.
Although the practice of routinely lavaging the abdominal cavity of animals is
controversial, lavage is always indicated with diffuse peritonitis. Lavage should be done
with care in animals with localized peritonitis to avoid dissemination of infection.
Open abdominal drainage is a useful technique for managing animals with peritonitis.
Reported advantages include improvement in the patient’s metabolic condition secondary
to improved drainage, less formation of abdominal adhesions and abscesses, and access
for repeated inspection and exploration of the abdomen. With this technique the abdomen
is left open, and sterile wraps are placed around the wound.
The prognosis for animals with generalized peritonitis is guarded; however, with proper
and aggressive therapy, many survive. Some authors have suggested that the mortality
rate approaches 50%. The mortality rates reported in animals with generalized peritonitis
treated with open abdominal drainage have varied from 20% to 48%
GENERAL PRINCIPLES AND TECHNIQUES
Definitions
Celiotomy is a surgical incision into the abdominal cavity. The term laparotomy often is used
synonymously, although it technically refers to a flank incision. A sudden onset of clinical
signs referable to the abdominal cavity (e.g., abdominal distention, pain, vomiting) is called an
acute abdomen.
Surgical Techniques
The abdomen generally is explored by means of a ventral midline incision from xyphoid to
pubis. In most animals the entire abdomen, including the inguinal areas, and the caudal
thorax should be prepared for aseptic surgery to allow extension of the incision into the
thoracic or pelvic cavities if necessary.
Ventral Midline Celiotomy in Cats and Female Dogs
With the patient in dorsal recumbency, make a ventral midline skin incision beginning near the
xiphoid process and extending caudally to the pubis. Sharply incise the subcutaneous tissues
until the external fascia of the rectus abdominis muscle is exposed. Ligate or cauterize small
subcutaneous bleeders and identify the linea alba. Tent the abdominal wall and make a sharp
incision into the linea alba with a scalpel blade. Palpate the interior surface of the linea for
adhesions. Use scissors to extend the incision cranially or caudally (or both) to near the
extent of the skin incision. Digitally break down the attachments of one side of the falciform
ligament to the body wall or excise it and remove it entirely if it interferes with visualization of
cranial abdominal structures. Clamp the cranial end of the falciform ligament and ligate or
cauterize bleeders before removing it.
Ventral Midline Celiotomy in Male Dogs
Patients undergoing exploratory laparotomy for abdominal trauma should have the prepuce
and penis aseptically prepared for surgery and they should remain in the surgical field;
particularly if lower urinary trauma is suspected. Make a ventral midline skin incision
beginning at the xiphoid process and continuing caudally to the prepuce. Curve the incision to
the left or right of the penis and prepuce and extend it to the level of the pubis. Incise the
subcutaneous tissues and fibers of the preputialis muscle to the level of the rectus fascia in
the same plane as the skin incision. Ligate or cauterize large branches of the caudal
superficial epigastric artery and vein at the cranial aspect of the prepuce. Retract incised skin,
prepuce and penis and subcutaneous tissues laterally to locate the linea alba and external
fascia of the rectus abdominis muscle. Do not attempt to locate the caudal linea alba until
subcutaneous tissues have been incised and the abdominal musculature fascia identified.
Tent the abdominal wall and make a sharp incision into the linea alba with a scalpel blade.
Palpate the interior surface of the linea for adhesions. Use scissors to extend the incision
cranially or caudally (or both) to near the extent of the skin incision.
Abdominal Exploration
Systematically explore the entire abdomen. Various techniques may be used; however, every
surgeon should develop a consistent pattern to ensure that the entire abdominal cavity and all
structures are visualized and/or palpated in each animal.
Use moistened laparotomy sponges to protect tissues from drying during the procedure. If
generalized infection is present or if diffuse intraoperative contamination has occurred, flush
the abdomen with copious amounts of warmed, sterile saline solution with no additives (i.e.,
antiseptics or antibiotics). Remove the lavage fluid and blood and inspect the abdominal
cavity before closure to ensure that all foreign material and surgical equipment have been
removed. Perform a sponge count and compare it with the preoperative count to ensure that
surgical sponges have not been left in the abdominal cavity.
Abdominal Wall Closure
The linea alba may be closed with a simple continuous (author’s preference) or a simple
interrupted suture pattern. The simple continuous technique does not increase the risk of
dehiscence when properly performed (i.e., secure knots, appropriate suture material,
adequate bites in the rectus sheath), and it allows for a rapid and more secure closure.
Synthetic monofilament absorbable suture (Maxon, PDS) should be used for continuous
suture patterns, and six to eight knots should be placed at each end of the incision line.
On each side of the incision, engage a 5 to 7 mm bite of white rectus sheath with each suture.
Place sutures no further apart than 3 to 4 mm, depending on the animal’s size. Tighten
sutures sufficiently to appose but not enough to strangulate tissue, because sutures that
strangulate tissue negatively affect wound healing. Incorporate full thickness bites of the
abdominal wall in the sutures if the incision is midline (i.e., through the linea alba). If the
incision is lateral to the linea alba and muscular tissue is exposed (i.e., paramedian incision),
close the external rectus sheath without including muscle or peritoneum in the sutures. Close
subcutaneous tissues with a simple continuous pattern of absorbable suture material and
reappose the preputialis muscle fibers in the male dog. Use nonabsorbable sutures (simple
interrupted or continuous appositional pattern) or stainless steel staples to close skin. Place
skin sutures without tension.
Complications
Dehiscence (incisional hernias) may occur if improper surgical technique is used (see the
above discussion). The most common cause of wound dehiscence in the early postoperative
period results from the surgeon’s inability to recognize the rectus sheath or not getting
adequate bites in the rectus sheath. Bites should engage at least 5 to 7 mm or more
depending upon patient size.
TRAUMATIC ABDOMINAL WALL HERNIAS
Definitions
External abdominal hernias are defects in the external wall of the abdomen that allow
protrusion of abdominal contents; internal abdominal hernias are those that occur through a
ring of tissue confined within the abdomen or thorax (i.e., diaphragmatic hernia, hiatal hernia).
External abdominal hernias may involve the abdominal wall anywhere other than the
umbilicus, inguinal ring, femoral canal, or scrotum.
Surgical Treatment
patients that sustain penetrating abdominal wounds (i.e., gunshot, bite wounds) should have a
xyphoid to pubis abdominal exploratory laparotomy. All visceral structures should be carefully
examined to signs of trauma (e.g., mesenteric rents, ruptured hollow viscous organs, avulsed
kidney, ureteral damage). In addition, abdominal ceiliotomy approach facilitates abdominal
hernia closure. Most abdominal hernias can be repaired by suturing torn muscle edges or
apposing the disrupted abdominal wall edge to the pubis, ribs, or adjacent fascia. In rare
cases synthetic mesh must be used to repair the defect. Some hernias (i.e., intestinal
strangulation, urinary obstruction, concurrent organ trauma) require emergency surgical
correction. The extent of devitalized muscle may not be apparent initially, however, for
patients in stable condition, delaying surgery until muscle damage can be accurately
assessed facilitates surgical correction. The most common complications of surgery are
hernia recurrence and wound infection. Abdominal hernias that occur secondary to bite
wounds usually are contaminated; wound infection and dehiscence of the skin or hernial
repair (or both) may occur. Mesh should not be placed in these hernias, hernial closure is
performed during exploratory laparotomy, and the skin wounds should be left open to drain.
Treatment of infected wounds includes cultures, drainage, antibiotics, and/or flushing.
Positioning
For ventral hernias the animal is placed in dorsal recumbency and the area around the hernia
is prepared for aseptic surgery. Repair of ruptures of the cranial pubic ligament may be
facilitated by placing the animal in dorsal recumbency with the rear limbs flexed and pulled
cranially.
Surgical Techniques
Abdominal Hernias
For most abdominal hernias, perform a ventral midline abdominal incision to allow the entire
abdomen to be explored. Assess the extent of visceral herniation. Reduce the herniated
contents and amputate or excise necrotic or devitalized tissue around the hernia. Close the
muscle layers of the hernia with simple interrupted or simple continuous sutures.
Cranial Pubic Ligament Hernias
Make a ventral midline skin incision and identify the ruptured tendon and its pubic insertion.
Evaluate the inguinal rings and vascular lacuna; these hernias may extend into the femoral
region as a result of rupture of the inguinal ligament. Reattach the free edge of the abdominal
wall to the cranial pubic ligament with simple interrupted sutures. As an alternative, suture the
tendon remnant to the muscle fascia and periosteum covering the pubis or anchor it to the
pubis by drilling holes in the pubic bone through which sutures can be placed. If the hernia
extends into the femoral region, it may be necessary to suture the body wall to the medial
fascia of the adductor muscles. When doing so, take care to avoid damaging the femoral
vessels or nerves.
Prognosis
The prognosis generally is good, and recurrence is uncommon. When recurrence occurs, it
generally is noted within a few days of surgery. Most animals have excellent long-term results
when appropriate techniques are used.
PERITONITIS
Definition
Primary generalized peritonitis refers to spontaneous inflammation of the peritoneum
without any pre-existing intra-abdominal pathologic condition. Secondary generalized
peritonitis occurs in conjunction with an intra-abdominal pathologic condition and may be
further classified as infectious or noninfectious.
Surgical Treatment
Abdominocentesis (see below) is the percutaneous removal of fluid from the abdominal
cavity, usually for diagnostic purposes, although it may occasionally be therapeutic.
Indications include shock without apparent cause, undiagnosed disease with signs involving
the abdominal cavity, suspicion of postoperative gastrointestinal dehiscence, blunt or
penetrating abdominal injuries (i.e., gunshot wounds, dog bites, vehicular injury), and
undiagnosed abdominal pain. A multifenestrated catheter should be used to enhance fluid
collection. Physical and radiographic examinations should precede abdominocentesis to rule
out instances in which it may not be safe and to guide needle placement. Four-quadrant
paracentesis may be performed if simple abdominocentesis is not successful in retrieving
fluid. It is similar to simple abdominocentesis except that multiple abdominal sites are
assessed by dividing the abdomen into four quadrants through the umbilicus and tapping
each of these four areas. Diagnostic peritoneal lavage should be performed in animals
suspected of having peritonitis if the above methods are unsuccessful in obtaining fluid for
analysis.
Exploratory surgery is indicated when the cause of peritonitis cannot be determined or when
bowel rupture, intestinal obstruction (e.g., bowel incarceration, neoplasia), or mesenteric
avulsion is suspected. Serosal patching and plication reduce the incidence of intestinal
leakage, dehiscence, or repeated intussusception. Animals that require surgery and that have
peritonitis secondary to intestinal trauma (disruption of mesenteric blood supply, bowel
perforation, chronic intussusception, foreign body) often are hypoproteinemic. The role that
protein levels play in healing intestinal incisions is not well understood. However, most
surgeons are concerned that hypoproteinemic patients may not heal as quickly as patients
with normal protein levels, despite one study that showed similar complication rates among
animals with normal protein levels and those that were hypoproteinemic and undergoing
intestinal surgery. Most experimental evidence has shown that retardation of wound healing is
not seen with moderate protein depletion but only with severe deficiencies (<1.5 to 2 g/dL).
Although the practice of lavaging the abdominal cavity of animals with peritonitis is
controversial, lavage generally is indicated with diffuse peritonitis. Lavage should be done
with care in animals with localized peritonitis to avoid dissemination of infection. When lavage
is performed, as much of the fluid as possible should be removed because fluid inhibits the
body’s ability to fight off infection, probably by inhibiting neutrophil function. Historically, many
different agents have been added to lavage fluids, especially antiseptics and antibiotics.
Povidone-iodine is the most widely added antiseptic; however, its use may be contraindicated
with established peritonitis. Furthermore, no beneficial effect of this agent has been shown in
repeated experimental and clinical trials in animals. Although a great many antibiotics have
been added to lavage fluids over the years, there is no substantial evidence that their addition
is of any benefit to patients who are being treated with appropriate systemic antibiotics.
Warmed sterile physiologic saline is the most appropriate lavage fluid.
Open abdominal drainage (OAD) is a useful technique for managing animals with peritonitis.
Reported advantages include improvement in the patient’s metabolic condition secondary to
improved drainage, less formation of abdominal adhesions and abscesses, and access for
repeated inspection and exploration of the abdomen. With this technique the abdomen is left
open and sterile wraps are placed around the wound. The frequency of wrap changes
depends on the amount of fluid drained and the amount of external soiling. Complications of
open abdominal drainage include persistent fluid loss, hypoalbuminemia, weight loss,
adhesion of abdominal viscera to the bandage, and contamination of the peritoneal cavity with
cutaneous organisms.
There is evidence to suggest the use of Jackson Pratt drains are an efficient means of
draining the peritoneal cavity for 2 to 4 days postoperatively. This technique allows the
surgeon to perform a primary abdominal closure yet still provide abdominal drainage.
Positioning
For abdominocentesis and diagnostic lavage, the abdomen should be clipped and prepared
aseptically. These procedures may be performed with the animal in lateral recumbency or
standing.
Abdominocentesis
Insert an 18- or 20-gauge, 1½ -inch plastic over-the-needle catheter (with added side holes)
into the abdominal cavity at the most dependent part of the abdomen. Do not attach a syringe;
instead allow the fluid to drip from the needle and collect in a sterile tube. If sufficient fluid is
obtained, place it in a clot tube and an ethylenediamine tetraacetic acid (EDTA) tube, submit
samples for aerobic and anaerobic culture, and make four to six smears for analysis. If fluid is
not obtained, apply gentle suction using a 3-mL syringe.
It is difficult to puncture bowel by this method because mobile loops of bowel move away from
the tip of the needle as it strikes them. Perforations created by a needle this size usually heal
without complications. The major disadvantage of needle paracentesis is that it is insensitive
to the presence of the small volumes of intraperitoneal fluid and thus a negative result can be
meaningless. At least 5 to 6 mL of fluid per kilogram of body weight must be present in the
abdominal cavity of dogs to obtain positive results in most cases using this technique.
Diagnostic Peritoneal Lavage
Make a 2-cm skin incision just caudal to the umbilicus and ligate any bleeders to avoid falsepositive results. Spread loose subcutaneous tissues and make a small incision in the linea
alba. Hold the edges of the incision with forceps while the peritoneal lavage catheter
(Stylocath) without the trocar is inserted into the abdominal cavity. Direct the catheter caudally
into the pelvis. With the catheter in place, apply gentle suction. If blood or fluid cannot be
aspirated, connect the catheter to a bottle of warm sterile saline and infuse 20 mL/kg of fluid
into the abdominal cavity. When the calculated volume of fluid has been delivered, roll the
patient gently from side to side, place the bottle on the floor, vent it, and collect the fluid by
gravity drainage. Do not be surprised if you do not retrieve all of the fluid, particularly in
dehydrated animals.
Exploratory Laparotomy
Perform a ventral midline incision from the xiphoid process to the pubis. Obtain a sample of
fluid for culture and analysis. Explore and inspect the entire abdomen. Find the source of
infection and correct it. Break down adhesions that may hinder drainage. Lavage the
abdomen with copious amounts of warm, sterile saline if the infection is generalized. Remove
as much necrotic debris and fluid as possible. Close the abdomen routinely, place an
abdominal drain, or perform open abdominal drainage.
Prognosis
The prognosis for animals with generalized peritonitis is guarded; however, with proper and
aggressive therapy, many survive. Some authors have suggested that the mortality rate
approaches 50%. The mortality rates reported in animals with generalized peritonitis treated
with open abdominal drainage have varied from 20% to 48%.
ANAL SACCULECTOMY; A NOVEL APPROACH
Key Points
• knowledge of anorectal anatomy and neuroanatomy is important to the surgeon
• remove all anal sac epithelium during anal sacculectomy
• use of a Foley catheter may facilitate anal sacculectomy
If you would like a video of this surgical procedure on DVD go to www.videovet.org or
contact [email protected]. You may click on the ‘Seminar Price’ for any DVD you
would like to purchase.
Introduction: Disorders involving the anus and rectum occur frequently in small
animal practice. In order to appropriately diagnose and treat these disorders,
knowledge of the regional anatomy, physiology, common clinical signs they produce,
and proper physical examination techniques are necessary.
Anatomy: The location and function of the following anatomic structures should be
reviewed prior to medical and surgical management of diseases of the anus and
rectum: internal and external anal sphincter muscle, anal sac and duct, circumanal
glands, caudal rectal artery, vein and nerve, and columnar zone of the anus. These
structures are commonly involved in many of the disease processes discussed below
and their preservation or removal plays an important part in the patient's ultimate
recovery.
The Anal Sphincter Muscle (From the introduction of a report on
hemorrhoidectomy written by WC Bornemeier and published in Am J of Proc,
Feb, 1960.): "The prime objective of a hemorrhoidectomy is to remove the offending
varicosity with as little damage as possible to the patient. Of all the structures in the
area, one stands out as the king. You can damage, deform, ruin, remove, abuse,
amputate, maim, or mutilate every structure in and around the anus except one. That
structure is the sphincter ani. There is not a muscle or structure in the body that has a
more keenly developed sense of alertness and ability to accommodate itself to varying
situations. It is like the goalie in hockey...always alert."
"They say man has succeeded where the animals fail because of the clever use of his
hands yet, when compared to the hands, the sphincter ani is far superior. If you place
into your cupped hands a mixture of fluid, solid, and gas and then, through an opening
at the bottom, try to let only the gas escape, you will fail. Yet the sphincter ani can do
it. The sphincter apparently can differentiate between solid, fluid, and gas. It
apparently can tell whether its owner is alone or with someone, whether standing up
or sitting down, whether its owner has his pants on or off. No other muscle in the
body is such a protector of the dignity of man, yet so ready to come to his relief. A
muscle like this is worth protecting."
Physiology: The rectum has little importance in digestion, and acts as a reservoir or
collecting tube for undigested waste. The most important physiologic function of the
rectum and anus is in the controlled act of defecation (i.e., continence).
Clinical Signs: Common clinical signs associated with diseases of the anus and
rectum include: dyschezia, hematochezia, tenesmus, anal licking, ribbon-like stools,
matting of anal hair, anal discharge, scooting, excessive flatulence and diarrhea.
Patients that present with any of the above clinical signs should have a thorough
physical examination with emphasis on the anorectal region, including a digital rectal
examination.
Physical Examination: A complete physical examination should be performed in all
patients with clinical signs specific for anorectal disease in order to rule-out systemic
disorders that manifest themselves with anorectal abnormalities (i.e.,pemphigus).
Specific examination of the anorectal region should include close visual examination
of the perineum, circumanal area, and base of the tail, as well as careful digital rectal
palpation. In many instances this may be all that is necessary to obtain a definitive
diagnosis. If a more detailed examination is needed, the use of an anal dilator or
proctoscope may be indicated.
These techniques require heavy sedation or general anesthesia to adequately
perform. Epidural anesthesia has proven to be an effective anesthetic regime for
examination of the anus and rectum. Excellent muscle relaxation allows easy anal
sphincter dilation and visualization of the anal canal and rectal mucosa. The patient is
placed in a perineal position for examination.
Sphincter muscle atonia or areflexia: This form of incontinence occurs when the
peripheral nervous supply to the external anal sphincter muscle or the muscle itself
has been partially or totally severed. The external anal sphincter muscle is made up
of striated muscle fibers, and is partially responsible for the voluntary control of
defecation.
Isolated injury of the pudendal nerve to the external anal sphincter is uncommon, but
may occur from iatrogenic causes. Injury can occur during the following surgical
procedures:
1. Perianal fistula repair-cryosurgery or excision
2. Perianal gland adenoma removal-cryosurgery or excision
3. Perineal hernia repair
4. Anal sacculectomy
5. Anoplasty procedures
6. Removal of malignant neoplasm
When this type of injury occurs, the patient may still be considered an appropriate
house pet. With loss of anal sphincter tone, fine control of defecation is lost, but the
patient still has the ability to sense the urge to defecate and can position
properly. However, the fine control necessary to terminate a bowel movement without
dropping a piece of stool is compromised. Also, when the patient is excited, startled,
or barks loudly causing increased intra-abdominal pressure; a piece of stool may drop
out of the rectum. The important thing to remember is that the patient retains the urge
to defecate and can control, to some extent, bowel movements.
Anal Sacculitis: Anal sac impaction and abscessation is the most common anorectal
disorder diagnosed by the small animal practitioner. Diagnosis is confirmed by clinical
signs, visual and digital rectal examination. Relief of impaction by digitally expressing
the anal sacs is easily performed during rectal examination. If abscessation is
present, infusion of an antibiotic preparation may be sufficient to eliminate the
infection. Systemic antimicrobial treatment may be required in resistant cases. If
abscessation becomes a chronic recurrent problem, surgical excision of both anal
sacs is the treatment of choice. Surgery should be delayed however until the
immediate infection or abscess has been controlled medically as described above.
Surgical Techniques: There are a variety of techniques currently used to
successfully remove anal sacs. One such technique includes using a pair of
Metzenbaum scissors to cut into the anal sac through the duct. The sac is opened to
expose the glistening greyish colored interior lining. Hemostats are used to grasp the
full thickness of the anal sac wall, being careful to avoid the external anal sphincter
muscle fibers. A number 15 BP scalpel blade is used to carefully scrape the gland
from the underlying external anal sphincter muscle. The external anal sphincter m.,
subcutaneous tissue and skin are closed with a synthetic absorbable suture material
in a simple interrupted pattern.
An alternate method is to incise over the anal sac, dissect through the subcutaneous
tissue, locate the sac and excise it toward the duct.
Regardless of the procedure used, if the entire anal sac is removed and the caudal
rectal nerve avoided the prognosis is excellent.
Foley Catheter Technique (the authors’ preferred technique)
A novel approach for safely and completely removing anal sacs relies on the use of a
6 French Foley catheter with a 3cc bulb. The Foley catheter is placed into the anal sac
through the anal sac orifice and its cuff inflated. Once introduced into the sac, the
Foley catheter bulb is inflated with 2-3 cc of air or saline. The bulb distends the anal
sac making identification and palpation of the gland simple. The protruding catheter
allows the surgeon, or the surgeon’s assistant, to place gentle traction on the gland
during dissection. A 360-degree skin incision is made around anal sac duct and the
protruding catheter. Care is taken to leave at least 2mm of skin from the anal sac duct
and the incision. Metzenbaum scissors (curved) are then used to dissect to the plane
of tissue between the anal sac wall and external anal sphincter. Identification of the
wall is made by identifying its grayish color in comparison to the deep red color of
external anal sphincter muscle fibers that will be carefully dissected off of the anal sac
wall. As the dissection progresses constant traction is placed on the Foley catheter to
accentuate to sac. When performing the deep dissection of the sac wall care is taken
to make certain the dissection does not go deep to the sac wall. This is the location of
the caudal rectal nerve fibers. Dissection is continued until the sac is completely
disected free and removed from its surrounding tissue.
Closure consists of suturing together any cut fibers of the external anal sphincter
muscle with 3-0 Maxon and the skin closed with 4-0 Biosyn using an intradermal
technique. This is the authors preferred technique for anal sacculectomy.
This technique is illustrated on the Anal Sacculectomy video located in the GI Surgery
I DVD. Check it out at www.videovet.org.
SURGICAL MANAGEMENT OF BRACHYCEPHALIC SYNDROME
Key Points
• English bulldogs are significantly over-represented.
• Light general anesthesia is required for accurate evaluation of laryngeal function
and defects.
• Limited use of crushing clamps and cautery results in less postoperative swelling.
• Overall prognosis for dogs with brachycephalic syndrome is favorable.
If you would like a video of these surgical procedures on DVD go to www.videovet.org
or contact the author at [email protected]. You may click on the ‘Seminar Price’ for
any DVD you would like to purchase.
Definition: Brachycephalic syndrome is a combination of upper airway disorders
commonly seen in brachycephalic breeds (e.g., English bulldogs, Boston terriors,
Pugs). Disorders associated with this syndrome include stenotic nares, elongated
soft palate, and everted laryngeal saccules. Occasionally patients present with
laryngeal collapse. Patients may present with any combination of above listed
disorders.
Diagnosis
Clinical presentation:
Signalment: Brachycephalic breeds are most commonly affected (i.e., English
bulldog, French bulldog, Boston terrier, Pug, Pekingese, Boxer, and Bull Mastiff). The
age at presentation ranges from less than one year to 11 years. The majority of
patients present between 1 and 4 years with English bulldogs presenting at a younger
age than other breeds. There is no apparent sex predisposition.
History: Historical findings are generally related to upper airway obstruction
and include noisy respiration, heat intolerance, exercise intolerance, cyanosis, and
occasionally syncopal attacks. Gagging, retching, and vomiting may also be reported.
Historical findings may vary depending upon the number of abnormalities present (i.e.,
stenotic nares, elongated soft palate, and/or everted laryngeal saccules). Generally,
the more abnormalities present the more severe the historical and clinical findings.
Clinical signs: The most frequently reported clinical signs in patients with
brachycephalic syndrome include noisy respirations and exercise and/or heat
intolerance. Moderate to severely affected patients or patients with multiple defects
may present with cyanosis and/or syncope.
Physical examination: Physical examination is generally normal except for patients
with stenotic nares. In patients with stenotic nares the wings of the nostril (i.e.,
dorsolateral nasal cartilage) obstruct airflow resulting in turbulent airflow and resultant
noise.
Examining the patient after exercise may exacerbate clinical signs (i.e., noise and
exercise intolerance) making diagnosis of brachycephalic syndrome more likely. Oral
examination of the awake patient is generally unrewarding as the laryngeal apparatus
and related abnormalities cannot be seen without light general anesthesia.
Radiography: Diagnosis of brachycephalic syndrome is based on signalment, history,
physical examination, and direct visualization of the laryngeal apparatus with the
patient under light general anesthesia. Thoracic radiographs are generally
recommended to rule out lower airway disorders such as tracheal hypoplasia and
pulmonary abnormalities.
Differential diagnosis: Any disorder causing noisy respirations, exercise intolerance,
cyanosis, and syncope. Included are laryngeal mass, laryngeal collapse and laryngeal
paralysis.
Medical management: Medical management is directed at decreasing airway
turbulence and subsequent inflammation and edema. Strict confinement,
antiinflammatory medications (e.g., steroids, NSAIDS), and a cool environment are
recommended. Obese patients should be placed on a weight reduction diet plan. As
medical management does nothing to change the anatomic deformity of the disorder,
it is considered palliative but not curative.
Surgical treatment: The objective of surgical treatment is to provide an adequate
airway by relieving any anatomic obstruction.
Preoperative management: Use of anti-inflammatory medication preoperatively is
generally recommended. Patients are given intravenous steriods (dexamethasone 0.5
- 1 mg/kg IV) at the time of anesthetic induction.
Anesthesia: Anesthetic management is somewhat dependent upon the severity of
clinical signs at presentation and degree of airway abnormality.
Patients with mild signs may be anesthetized with the clinicians’ standard
anesthetic protocol. Careful evaluation of the laryngeal apparatus is performed prior to
intubation and while the patient can still breath on its own (i.e., light general
anesthesia). Laryngeal function is carefully evaluated during inspiration and
expiration.
Patients with moderate clinical signs may need to be preoxygenated prior to
induction. Induction should be performed quickly, the laryngeal anatomy and laryngeal
function examined thoroughly, and the patient intubated to establish an open airway.
Patients with severe clinical signs should be preoxygenated 5 to 10 minutes
prior to induction. A vagolytic agent (i.e., atropine) should be considered 10 to 15
minutes prior to induction because vagal tone is generally increased and
cardioinhibitory reflexes are enhanced. Induction should be quick, examination of the
laryngeal anatomy and function performed, and the patient intubated to establish an
open airway.
Laryngeal examination: Once the patient is under a light plain of anesthesia
laryngeal function is evaluated. Care is taken to observe for evidence of largngeal
collapse, elongated soft palate, and everted laryngeal saccules.
Surgical anatomy: The soft palate in the dog forms a long and broad movable
partition between the oral and nasopharynx. The cranial border is attached to the
bony palate; the caudal margin forms the dorsal border of the opening from the mouth
into the pharynx. This portion of the palate is in contact with the epiglottis during
normal inspiration; during deglutition, the epiglottis moves away from the soft palate to
protect the opening of the glottis. At the same time the soft palate moves dorsally to
close the nasopharynx and prevent regurgitation of material into the nasal cavity. The
dorsal nasopharyngeal surface has a mucous membrane lining continuous with that of
the nasal cavity and a slightly convex contour. The mucous membrane of the ventral
concave surface is a continuation of the lining of the hard palate and is referred to as
the oral surface of the soft palate.
Relevant pathophysiology: Protrusion of an elongated soft palate into the laryngeal
inlet during respiration significantly obstructs air passage into the glottis. Stenotic
nares, when present, contribute to the severity of the occlusion by increasing the
inspiratory effort (and subsequent negative pressure) thus drawing the soft palate
deeper into the larynx. Edema and inflammation result from friction against the
epiglottis during each respiration. The resultant thickening further lessens airflow. As
increased inspiratory effort continues, increased negative pressure in the airway
encourages laryngeal saccules to evert.
Positioning: Patients may be positioned in ventral or dorsal recumbancy.
Stenotic nares: The author prefers ventral recumbancy with the head supported on
towels so the head position is normal and functional.
Elongated soft palate and everted saccules: Patients can be operated in either ventral
or dorsal recumbancy. In dorsal recumbancy, the maxillary canine teeth are taped
securely to the operating table. The mandibular canine teeth are taped to an ether
stand situated over the patients head. The mouth is opened wide to enhance
visualization. This positioning is critical as oral cavity exposure is key to adequate
visualization and instrumentation.
In ventral recumbancy, the maxillary canine teeth are ‘hooked’ over the bar of an ether
stand. The mandibular canine teeth are then taped to the operating table in such a
fashion that the mouth gapes open. The tongue is grasped with tongue forceps and
gently pulled from the mouth.
Surgical technique: The surgical technique varies depending upon the defect to be
repaired.
Stenotic nares: This technique is illustrated on the Respiratory Surgery I DVD
available via www.videovet.org.
Stenosis is decreased by removing a horizontal wedge of alar cartiladge from the wing
of the nostril. The flap created is sutured to remaining tissue of the wing of the nostril
using 3-0 or 4-0 Dexon or Vicryl in a simple interrupted suture pattern. Two or three
sutures is all that is generally required to complete the nasoplasty.
An alternate technique gaining popularity in Shih Tzu and Boston breeds is to
completely excise the alar cartilage. Bleeding is controlled by wedging a gauze
sponge in the patient’s nostril for 5 minutes by the clock.
Presurgical temporary tracheostomy?: Use of a presurgical tracheostomy facilitates
exposure and visualization of the soft palate and laryngeal saccules. However, it is not
necessary in the majority of patients. The author considers use of a tracheostomy in
patients that present with severe clinical signs (i.e., cynosis, syncope) and have a
combination of defects to repair. Tracheostomy is preferred over exiting the
endotracheal tube through a pharyngostomy as the tracheostomy can be used in the
postoperative management of the patient if necessary. In our hospital, regardless of
the severity of the airway obstruction, the patient is recovered in a critical care
environment and instruments necessary to perform an emergency tracheostomy are
readily available.
Elongated soft palate: This technique is illustrated on the Respiratory Surgery I DVD
available via www.videovet.org.
The patient is placed in ventral or dorsal recumbancy with the mouth opened widely
(see positioning). A broad malleable retractor is used to retract the tongue caudally;
this greatly facilitates visualization of the soft palate and laryngeal structures. A
headlamp facilitates visualization but is not necessary. Since postoperative edema
and swelling are of major concern following soft palate surgery, it is important to keep
surgical trauma to a minimum. Use of clamps and electrocautery may cause
excessive surgical inflammation and should be avoided. The soft palate is evaluated
for extent of resection. A Babcock or Allis tissue forceps is used to grasp the caudal
margin of the soft palate. The length of the soft palate in relation to the tonsil and
epiglottis is examined. The soft palate should extend no further caudal than the
midpoint of the tonsil. Alternately, the incision is made at the point where the soft
palate just slightly overlaps the tip of the epiglottis.
Once this line of excision is determined, a 3-0 or 4-0 Dexon or Vicryl stay
suture is placed in the soft palate on each lateral margin of the proposed excision. A
third stay suture is placed on the margin of the central portion of the soft palate. The
incision is begun from the left or right margin and one-third to one-half of the soft
palate is incised.
Using the long end of one of the 3-0 or 4-0 Dexon or Vicryl stay sutures, the
incised nasal mucosa is sutured to the incised oral mucosa using a simple continuous
suture pattern. Dexon or Vicryl is chosen because of its soft supple nature; Maxon or
PDS are much to stiff and may cause irritation to the oral cavity. Hemorrhage is
controlled by suture pressure. No attempt is made to cauterize or clamp bleeding
vessels. When the palate excision and suturing are complete, the stay sutures are cut
and the remaining soft palate replaced and evaluated once again for extent of
resection.
Everted laryngeal saccule resection: There is some suggestion that if the stenotic
nares and elongated soft palate can be successfully treated (see above), the lateral
saccules will return to their normal location in the larynx and no longer cause airway
obstruction without the need for surgical resection. The author only removes lateral
saccules in patients that present with severe respiratory signs (i.e., severe cyanosis,
syncope).
When removing laryngeal saccules, the patient is placed in dorsal recumbancy
with the mouth opened widely. Everted laryngeal saccules appear as edematous,
translucent tissue balls lying in the ventral aspect of the glottis and obscuring the
vocal folds.
Surgical removal is performed using a sharp long-handled laryngeal cup biopsy
forceps (or similar long handled biopsy instrument) or a long handled Allis tissue
forceps and #15 BP scalpel blade. If a laryngeal cup biopsy forceps is used the
everted saccule is grasped and amputated with the biopsy forceps. Any remaining
tags are grasped with a long-handled DeBakey forceps and trimmed with a #15 BP
blade or scissors. If an Allis tissue forceps is used the laryngeal saccule is grasped
with the Allis forceps and a long-handled scalpel with a #15 BP blade is used to
excise the saccule at its base.
If the patient had a tracheostomy tube placed prior to surgery, the saccules are
easily visualized and excised as described above. If the patient has an endotracheal
tube exiting the laryngeal apparatus, the tube is temporarily removed while the
saccules are excised.
Suture material/special instruments:
Malleable retractors, head lamp, long-handled laryngeal cup biopsy forceps (or similar
instrument), long-handled Allis tissue forceps, long-handled scalpel handle, longhandled rat tooth forceps, 3-0 or 4-0 Dexon or Vicryl with a cutting or sharp taper
needle.
Postoperative care and assessment: Any patient requiring surgery to relieve airway
obstruction should be monitored carefully (preferably in a critical care environment) for
the first 24 hours postoperatively. The degree of care may vary depending upon the
patients presenting signs and surgical manipulations required to correct the airway
obstruction. Examples of the authors’ degree of postoperative care based on patient
presentation and surgery performed are listed below:
Stenotic nares only: These patients are generally held for observation 12 – 24 hrs
postoperatively and discharged from the hospital the day following surgery.
Soft palate resection only: Patients that present with mild clinical signs (i.e., noise,
mild exercise or heat intolerance) and are bright and alert 24 hours after surgery can
be discharged that day. Patients that present with moderate to severe clinical signs
(i.e., severe exercise intolerance, episodes of cyanosis, syncopal attacks) are
monitored in a critical care environment until signs resolve. Immediate postoperative
gagging and coughing are observed in about 13% of patients. Patients requiring a
tracheostomy prior to surgery, or an emergency tracheostomy, remain in a critical
care environment until the tracheostomy can be removed.
Combined nares, palate, saccule repair: These patients are treated similarly to
patients with soft palate resection and are based on presenting clinical signs. Patients
with multiple defects tend to present with moderate to severe clinical signs and may
require more intensive care. Immediate postoperative gagging and coughing are
observed in about 80% of patients.
Patients that present with mild clinical signs (i.e., noise, mild exercise or heat
intolerance) and are bright and alert 24 hours after surgery can be discharged that
day. Patients that present with moderate to severe clinical signs (i.e., severe exercise
intolerance, episodes of cyanosis, syncopal attacks) are monitored in a critical care
environment until signs resolve. Patients requiring a tracheostomy prior to surgery, or
an emergency tracheostomy, remain in a critical care environment until the
tracheostomy can be removed.
Prognosis: Prognosis for patients with brachycephalic syndrome is generally
dependant upon the defects found at presentation.
Stenotic nares only: About 96% of dogs with stenotic nares will improve
postoperatively.
Soft palate resection only: About 85 – 90% of dogs with soft palate resection only will
improve postoperatively. Young dogs (i.e., less than 2 years of age) are more likely to
improve (90%) than dogs greater than 2 years of age (70%).
Stenotic nares and soft palate resection: Dogs having a combination of stenotic nares
repair and soft palate resection are more likely to have a favorable outcome (96%)
compared to those that did not (70%).
Soft palate and everted saccule resection: Dogs having this combination of defects
repaired will have an 80% chance of significant improvement postoperatively.
SURGICAL MANAGEMENT OF CANINE CALCULI
If you would like a copy of the illustrated version of these notes on CD and a video of this
surgical procedure on DVD go to www.videovet.org.
Key Points
• Patients with urethral calculi present with stranguria
• Retropulsion of urethral calculi into the urinary bladder simplifies management of urethral
calculi
• Aggressive lavage of the urethra and bladder should be performed during cystotomy
• Permanent urethrostomy is an acceptable method of managing chronic stone formers
Definition: Cystic and urethral calculi have various compositions (i.e., oxalate, struvite, urate,
uric acid, cystine, silicate) and may be present in the urinary bladder or lodged in the urethra,
respectively. They may be multiple or single, may cause partial or complete obstruction (i.e.,
urethral), and may require surgical manipulation for removal.
Synonyms: Bladder stones, urethral stones
Diagnosis
Signalment: There is no age predisposition. Dalmations are more likely to present with
uric acid calculi and commonly present with calculi lodged in the urethra. Schnauzers are
more likely to present with struvite calculi and Daschunds are more likely to present with
cystine stones.
History: Patients generally present with a history of urinary obstruction and/or signs of
urinary tract infection. Common complaints include difficulty urinating, straining to urinate,
hematuria, dripping blood tinged urine from the prepuce, and/or a distended abdomen.
Patients that present several days after complete obstruction may have a distended and
painful abdomen and a history of anuria. These patients may be so compromised that they
present in shock.
Clinical signs: The most frequently reported clinical signs in patients with cystic and
urethral calculi include unproductive straining to urinate, blood tinged urine dripping from the
prepuce, hematuria, and/or polakiuria. Severity of clinical signs may vary with the degree of
urethral obstruction and duration of obstruction prior to presentation. Patients with complete
obstruction for several days may show signs of post-renal azotemia (i.e., severe depression,
recumbant, shocky).
Physical examination: Observation in the examination room may reveal multiple
unsuccessful attempts to urinate. Abdominal palpation may reveal a full urinary bladder;
occasionally, calculi within the bladder may be palpable.
Patients with severe clinical signs (i. e., presented several days after complete
obstruction) may show azotemia, shock, and/or severe depression. Abdominal palpation
generally reveals a large, turgid urinary bladder and may result in discomfort to the patient.
Laboratory findings: Results of a complete blood count and serum chemistry profile are
generally normal in patients presenting acutely; urinalysis may show evidence of urinary tract
infection and and/or crystalluria.
Patients presenting after several days of complete obstruction may have significant
changes in their biochemical profile including increased BUN, increased creatine, metabolic
acidosis, and severe electrolyte abnormalities. Urine is generally grossly hemorrhagic and
urinalysis may show signs of urinary tract infection and crystaluria.
Radiography: Survey radiographs may show presence of radiodense calculi in the urethra
and/or urinary bladder as well as a distended urinary bladder. Occasionally, radiolucent calculi
occur and can only be visualized using retrograde contrast cystourethrography. The most
common location of urethral calculi in male dogs is immediately caudal to the os penis.
Careful evaluation of the kidneys and ureters should be done to rule out renal and ureteral
calculi.
Ultrasound: Ultrasonographic examination of the bladder, ureters, and kidneys may be
helpful in diagnosis of cystic, ureteral, or renal calculi.
Differential diagnosis: Any disorder causing urinary obstruction, including urethral neoplasia,
granulomatous urethritis, urethral stricture, and urethral trauma. Definitive diagnosis is based
on clinical signs, inability to pass a catheter, and evidence of calculi on survey or contrast
radiographs.
Medical management: Immediate care: In animals with complete obstruction of a duration
long enough to cause azotemia, temporary urinary diversion is provided by either passing a
small urinary catheter (e.g., 5 French) alongside the calculus, performing a prepubic
cystostomy (see technique described below), or frequent cystocentesis (i.e, tid to qid).
Azotemia is treated with crystalloid IV therapy prior to calculus removal.
Retrograde hydropulsion: See the DVD for a detailed video of this technique.
This technique should result in a 90-95% success rate of retropulsing urethral calculi into the
urinary bladder!
Technique
1. Select the largest diameter sterile high density polypropylene urinary catheter that will fit
past your patients os penis (generally 6, 8, or 10 French diameter)
2. If the selected catheter turns out to be a 6 French diameter then mix 30cc of Sterile KY
Jelly with 70cc of sterile physiologic saline solution.
3. If the selected catheter turns out to be an 8 or 10 French diameter then mix 40cc of Sterile
KY Jelly with 60cc of sterile physiologic saline solution.
4. Thoroughly mix the sterile saline and KY Jelly in a 35 or 60 cc syringe and attach the
syringe to the urinary catheter.
5. Anesthetize the animal, extrude the penis and pass the lubricated urinary catheter in the
urethra up to and against the calculus. Place a dry gauze sponge around the extruded tip of
the penis and occlude the penis around the catheter by squeezing it with thumb and finger.
6. Using a back and forth action on the catheter, simultaneously inject the saline/lubricant mix
under extreme pressure. Be certain the catheter tip hits the calculus like a battering ram to
help dislodge it and encourage the saline-lubricant mix to surround the calculus and coat the
urethral wall. During injection the calculi and urethra are lubricated by the saline/lubricant mix
while the viscosity of the mixture (i.e., KY jelly and saline) encourages the calculus to dislodge
and become retropulsed into the urinary bladder.
This technique is successful regardless of how many stones are in the urethra and no matter
where the calculi are lodged.
If the above technique fails, place a finger in the rectum, palpate the urethra and occlude its
lumen (this dialates the urethra); repeat the above maneuvers and when maximum pressure
is exerted on the urethra by the saline/lubricant mix (i.e., the urethral is maximally dialated),
suddenly release digital urethral occlusion allowing lodged calculi to flush into the urinary
bladder.
Surgical treatment: The objective of surgical treatment is to remove all retropulsed calculi
from the urinary bladder and any remaining urethral calculi that were unable to be retropulsed.
Bladder calculi are removed via cystotomy, urethral calculi are removed via urethrotomy, and
patients that are frequent stone formers may benefit form a permanent urethrostomy to allow
continual passage of small urethral calculi.
Preoperative management: Patients that present acutely can be anesthetized
immediately and retropulsion attempted (see above described technique). If urinary tract
infection is suspected, preoperative treatment with antibiotics may be instituted.
Patients that present after several days of complete obstruction should be treated
medically until the azotemia resolves, blood gas abnormalities resolve, and electrolytes return
to normal. The patients electrocardiogram should be monitered if hyperkalemia is present
preoperatively. Medical treatment may consist of intravenous fluids, systemic antibiotics,
continuous ECG monitoring, and bladder decompression. Bladder decompression may be
accomplished via passing a small gauge urinary catheter (e.g., 5 French) past the calculus,
multiple cystocentesis (i.e., tid or qid), or placement of a antepubic cystostomy tube
(described in detail below).
Anesthesia: Routine general anesthesia is performed in patients that present acutely
without signs of azotemia.
Azotemic, shocky patients with moderate to severe biochemical abnormalities should
be treated as described above until these abnormalities return to normal.
Surgical anatomy: The male canine penile urethra consists of urethral mucosa (i.e.,
urothelium) surrounded by corpus cavernosum urethra, which is in turn surrounded by tunica
albuginea. Because of the fluid filled corpus cavernosum urethra (blood) and the tough fibrous
connective tissue tunica albuginea, the urethra can withstand tremendous pressure (e.g., as
with aggressive retropulsion) without the fear of urethral rupture.
The urinary bladder consists of the following layers; serosa, muscular, submucosa and
mucosa. The bladder is lined with transitional epithelium.
Positioning: Patients are positioned in dorsal recumbancy for retropulsion,
urethrotomy, urethrostomy, cystostomy tube placement and cystotomy.
Surgical technique: The surgical techniques vary depending upon the procedure
chosen, and are described in detail below:
Retropulsion: The technique for retropulsion of urethral calculi is described above in medical
management.
Percutaneous cystostomy tube placement: Occasionally, it may be necessary to perform a
percutaneous antepubic cystostomy to decompress the urinary bladder whilst treating a
severely azotemic patient until they become a better anesthetic and surgical risk.
The patient is sedated and placed in dorsal recumbancy. A 3-4cm incision is centered
between the umbilicus and pubis. Subcutaneous tissues are disected to expose the ventral
midline (i.e., linea alba). A 2-3cm incision is made in the linea alba and the bladder wall
located. A 12–14 French Foley catheter is advanced through a skin incision 2-3 cm lateral to
the abdominal incision, tunneled in the subcutaneous tissue and brought into the abdominal
cavity at a location just lateral to the midline abdominal incision. A pursestring suture is
placed in the bladder wall at the proposed site of Foley catheter placement with 3-0
monofilament absorbable suture. A 1cm incision is made into the bladder lumen and the Foley
catheter advanced. The pursestring suture is carefully tightened to create a water-tight seal,
but not to tight as to create bladder wall necrosis. The bladder wall is pexied to the abdominal
wall at the point of entry of the Foley catheter with 3-0 monofilament absorbable suture in a
simple interrupted pattern. The abdominal wall is closed in a routine fashion. and
The cystostomy catheter is held in place with a Chinese finger trap friction suture technique
using #1 monofilament nonabsorbable suture and attached to a closed collection system to
avoid urinary tract infection. The cystostomy tube remains in place until the patient is ready for
definitive surgical treatment.
Urethrotomy: See DVD for detailed video of this technique.
The urethral calculus to be removed is located by evaluation of radiographs, palpation of the
os penis and its relationship to the calculus, and/or passing a catheter in the urethra until it
contacts the stone, removing the catheter and using it as a measure to locate the calculus.
A 2–3 cm skin incision is made directly over the calculus. Subcutaneous tissues are dissected
until the retractor penis muscle is exposed. The cream colored retractor penis muscle (smooth
muscle) is dissected off the corpus cavernosum penis (the corpus cavernosum penis has a
bluish tint from venous blood) and retracted laterally. A sharpe #15 BP scalpel blade is used
to incise the urethra directly over the calculus being careful to incise the urethra directly on its
midline to help decrease cavernous sinus bleeding. No attempt is made to control cavernous
sinus hemorrhage with cautery or hemostats as this creates excessive urethral trauma and is
generally unsuccessful at controling hemorrhage. Rather, hemorrhage is controlled via digital
pressure and suction until suturing can commence. The calculus is grasped with forceps and
removed from the urethra.
The urethral incision can be left open to heal by second intention; if this method is chosen
moderate to severe hemorrhage can be expected for several days postoperatively.
Alternately, the urethral incision can be closed using 5-0 multifilament or monofilament
absorbable suture in a simple interrupted or continuous pattern. Subcutaneous tissues are
closed with 3-0 monofilament absorbable suture in a simple continuous pattern and skin with
3-0 or 4-0 nonabsorbable monofilament suture. If this method is preferred by the author over
healing by second intention as postoperative hemorrhage is significantly reduced.
Both urethrotomy techniques (i.e., sutureless or sutured) result in perdictable urethral healing
without evidence of urethral stenosis or stricture.
Urethrostomy: See DVD for detailed video of this technique.
Urethrostomy is generally performed in patients that are recurrent stone formers. It provides a
permanent opening caudal to the os penis that is large enough to accommodate passage of
most urethral calculi. This technique is often performed in Dalmations for treatment of
recurrent uric acid calculi.
Scrotal urethrostomy is the location of choice for urethrostomy in dogs. It is a convienent
location for surgical manipulation, this area of the urethra generally bleeds the least, the
urethral diameter will accommodate passage of most urethral calculi, and there is less urine
scald postoperatively. Other locations for urethrostomy include prescrotal and perineal.
Prior to surgery a urethral catheter (the largest size that will fit past the os penis) is passed, if
possible. After a routine castration and scrotal ablation have been performed, the
subcutaneous tissues are dissected to expose the retractor penis muscle. The retractor penis
muscle is smooth muscle and appears light grey to cream colored. The retractor penis muscle
is dissected from its attachment to the corpus cavernosum urethra. The blood filled cavernous
tissue gives the urethra a bluish color. The urethral catheter is palpated and used as a firm
surface to cut against when incising the urethra. Every attempt is made to incise the urethra
exactly on the midline to help decrease hemorrhage. A 3–4 cm incision is made in the urethra.
The caudal aspect of the urethral incision is positioned directly over the ishial arch. As this is
the new point of urine flow it is most efficent to have urine exit before it makes a sharp turn
ventrally. No attempt is made to control cavernous tissue hemorrhage with cautery or
hemostatic forceps; only pressure, suction, and suture pressure should be used.
After incision of the urethra, the glistening urethral mucosa is identified, 4-0 or 5-0
nonabsorbable monofilament suture with a swaged on cutting or taper-cut needle is
recommended by the author to suture urethral mucosa to skin. The first urethrostomy suture is
placed at the midpoint of either side of the urethral incision to include urethral mucosa, tunica
albuginea, and skin (suture split thickness of skin). The suture is tied leaving the end without
the needle 3-4 cm long to act as a stay suture. The second suture is placed directly across
from the first suture and tied as described for the first. The urinary catheter can now be
removed. After the first two sutures are placed, the needle end of one suture is used to begin
suturing the cranial portion of the urethrostomy using a simple continuous suture pattern.
When the opposite suture is encountered, the stay suture is used to tie off the first continuous
suture line. The opposite suture is then used to suture the caudal portion of the urethrostomy
in a similar fashion tying the final suture to the remaining stay suture. Fine ophthalmic
instruments make tissue handling and suturing easier. Use of a magnifying loupe (about 2x)
and head lamp light source enhances visualization of the urethral mucosa and facilitates
accurate suturing. It is critical that the surgeon recognize glistening urethral mucosa and
suture it to skin. This will decrease (or eliminate) the chance of urethral stricture. It has been
shown that a continuous suture pattern incorporating the urethral mucosa and tunica
albuginea (i.e., squeezes the cavernous tissue) results in less postoperative hemorrhage.
Cystotomy: See DVD for detailed video of this technique.
After successful retropulsion of urethral calculi into the bladder, the catheter used to
retropulse calculi is passed into the urethra and bladder and left in place. A portion of the
catheter can be left exiting the penis. Leaving a catheter indwelled in the urethra ensures that
remaining cystic calculi will not roll back into the urethra during patient transfer to the surgery
suite and during patient prep.
Just prior to aseptic preparation of the abdomen a soft, 10-12 French red rubber catheter or
feeding tube is placed into the prepuce and a prepucal lavage is performed with 180cc of a
1:50 dilution of saline and 1% betadine solution. This aseptically prepares the penis and
prepuce so they can remain in the surgical field throughout the cystotomy procedure. In
female patients the vulva and vaginal vault are similarily asepticlly prepared.
A paraperpucial incision is made from just caudal to the umbilicus to pubis. The prepuce is
retracted and a midline celiotomy is performed. The bladder is exteriorized and examined.
Stay sutures of 3-0 suture are placed in the apex and neck of the bladder. A scalpel blade is
used to penetrate the ventral aspect of the bladder and enter the lumen. The ventral
cystotomy incision is extended with metzenbaum scissors. The bladder should be opened
from apex to neck to allow proper visualization of bladder mucosa and calculi. Stay sutures
are placed on each side of the incision at its midpoint to facilitate visualization of the bladder
interior. Large hemostats are placed on the stay sutures to help retract the bladder margins to
maintain visualization of the bladder interior. A cystotomy spoon is used to scoop the bladder
neck for calculi. This is performed several times. When no more calculi can be removed with
the spoon, digital palpation of the bladder neck is performed to identify presence of further
calculi. If further calculi are palpated further attempts are made to retrieve the calculi. Once no
more calculi can be spooned or palpated the previously plced indwelling urethral catheter is
removed.
Next, the largest urinary catheter or feeding tube that can be passed through the os penis is
passed in the penile urethra to the level of the os penis (i.e., retrograde). A dry sponge is used
to grasp the extruded penis to create a water tight seal around the catheter. A 60cc syringe
filled with sterile saline is injected through the catheter under moderate pressure. The stay
sutures on the bladder incision are retracted to enable visualization of the bladder lumen
during lavage. Suction or intermittent spooning is performed during lavage in an attempt to
identify and remove any remaining stones. After several lavages and negative results in
obtaining stones, the catheter is placed from the bladder to the bladder neck and pelvic
urethra (i.e., normograde). Lavage is once again performed in an attempt to identify and
remove any remaining stones. After several lavages and negative results the catheter is
advanced until it can be seen coming out of the penile urethra. The catheter is run back and
forth in the urethra several times to ensure that there are no remaining calculi (i.e., gritty
feeling while passing the catheter).
Finally, a piece of bladder mucosa is excised from the cut edge of the cystotomy incision for
culture and susceptability testing. The interior of the bladder is examined for urachael
diverticulm, masses, etc. and biopsied as necessary. The bladder wall is closed with 3-0 or 40 absorbable monofilament suture material using a swaged on taper or taper-cut needle in a
simple continuous or simple interrupted appositional suture pattern. Only one layer closure is
necessary. Abdominal closure is routine.
Suture material/special instruments:
Urinary catheters of various sizes, Foley catheter, head lamp light source, 2X loupes,
ophthalmic instruments, 4-0 and 5-0 monofilament absorbable suture material.
Postoperative care and assessment:
Postoperative care varies depending upon procedure performed:
Percutaneous cystostomy tube: It is important to keep the percutaneous cystostomy tube
attached to a closed collection device. The tube can be connected to a sterile collection bag
via a sterile intravenous catheter connection set. An elizabethan collar may be necessary in
some patients to prevent iatrogenic removal of the cystostomy catheter. Careful management
is important to control catheter related urinary tract infection.
Sutureless Urethrotomy: If urethrotomy without suturing is performed, patients must be
monitored for blood loss from the urethrostomy site. Blood loss can be severe enough to
lower the PCV by 2 – 3%. An Elizabethan collar may be necessary in some patients to
prevent self-mutilation. Patients should be kept quiet and away from other animals (especially
bitches in heat!). Tranqulization is occasionally necessary to control hyperactive or overly
excitable patients. Clients should be warned that drops of blood may be present from the
urethrotomy site as long as 2 weeks postoperatively.
Sutured Urethrotomy: If a sutured urethrotomy is performed, patients will exhibit very little
blood loss. However, an Elizabethan collar should be considered, especially in patients that
may be prone to self-mutilation. Patients should be kept quiet and away from other animals
(especially bitches in heat!). Tranqulization is occasionally necessary to control hyperactive or
overly excitable patients.
Scrotal Urethrostomy: The most common postoperative complication of scrotal urethrostomy
is bleeding from the urethrostomy site. Utilization of a simple continuous suture pattern
incorproating the urethral mucosa and tunica albuginea (i.e., squeezing the cavernous tissue
and creating a air-tight/water-tight seal) has significantly decreased the incidence of
postoperative hemorrhage in the authors opinion. An Elizabethan collar should be considered,
especially in patients that may be prone to self-mutilation. Patients should be kept quiet and
away from other animals (especially bitches in heat!). Over excitement immediately
postoperatively can result in frank hemorrhage or subcutaneous hemorrhage. Tranqulization
is occasionally necessary to control hyperactive or overly excitable patients.
Cystotomy: An indwelling urethral catheter is not recommended after an uncomplicated
cystotomy for removal of cystic calculi. An Elizabethan collar should be considered, especially
in patients that may be prone to self-mutilation. Patients should be kept quiet and away from
other animals.
Prognosis: The prognosis for surgical management of urethral and cystic calculi is
dependant upon preoperative management of azotemic patients prior to anesthesia, success
of retropulsion of urethral stones into the urinary bladder, care in removing all stones via
cystotomy, and care of ensuring urethral mucosa to skin apposition during urethrostomy.
Patients that have successful retropulsion of urethral calculi and do not require urethotomy or
urethrostomy have a excellent prognosis. If careful attention is paid during cystotomy to
ensure that no calculi are left behind (see discussion on cystotomy technique), the prognosis
for cure is excellent. Long term prognosis is dependant on evaluaiton of calculus composition,
dietary management, management of urinary tract infection, and attention to urine pH.
Patients that require sutured or sutureless urethrotomy have a favorable prognosis if all of the
remaining calculi are removed from the urinary bladder via cystotomy to ensure that no calculi
are left behind (see discussion on cystotomy technique). Attention must be paid to careful
lavage during cystotomy to ensure removal of all cystic calculi.
Patients that have an elective urethrostomy have a favorable prognosis if attention is paid to
proper surgical technique (i.e., urethral mucosa is sutured to skin). Occasionally, chronic
stone forming patients will form a calculus that is to large to pass through the urethrostomy
stoma.
CHEST DRAIN PLACEMENT AND MANAGEMENT
surgical procedure on DVD, go to www.ivseminars.net and click Video Vet or contact
[email protected].
Key Points
• The most common types of intrapleural pathology requiring chest drain placement are air
and fluid.
• Careful handling of severely dyspnic patients during diagnostic work-up can be life saving.
• Careful attention to providing a sub q tunnel during chest drain placement prevents exit point
leak.
• Chest drain removal is based on quantity and character of fluid.
Definition: Pleural effusion is defined as the abnormal accumulation of fluid (i.e., blood, pus,
water, chyle, pseudochyle) in the interpleural space. As the accumulation of fluid increases,
the mechanical restriction of the lungs to normal ventilation may result in significant
hypoxia. Pleural absorption of certain exudates (e.g., pus) may result in systemic toxic
effects. Closed chest drainage alone (i.e., as for accumulations of blood, water, chyle, or
pseudochyle) or closed chest drainage and lavage (i.e., pus) may be necessary to return the
patient's pulmonary status to normal.
Synonyms: Thoracostomy tube, chest tube
Diagnosis
Signalment: Patients that present with disorders requiring the use of chest drain
management may be of any age, sex, or breed.
History: Historical findings in patients requiring chest drains are acute dyspnea or
chronic dyspnea with an acute exacerbation of severe dyspnea. A history of trauma is
common in patients that present with severe respiratory difficulty (i.e., pneumothorax).
Clinical signs: The most frequently reported clinical signs in patients requiring chest
drain placement is dyspnea. Signs may be mild, moderate, or severe depending upon the
amount of interpleural pathology (i.e., air, pus, blood, etc.). Occasionally patients present with
a chronic history of mild dyspnea then suddenly have an acute and severe attack requiring
urgent care.
Physical examination: Physical examination should be done with care. Over manipulation of
severely dyspnic patients can result in enough stress to cause respiratory decompensation
resulting in a catastrophic outcome. Minimal manipulation and pre-oxygenation can go a long
way in preventing the above scenario.
Laboratory findings: Results of a complete blood count, serum chemistry profile, and
urinalysis are dependent upon the patients underlying disorder.
Radiography: Diagnosis of interpleural disease (i.e., air, fluid) can be established with
thoracic radiographs. It is important to remember that the stress of positioning can be enough
to cause significant decompensation in a severely dyspnic patient. Pre-oxygenation and
careful handling are important prerequisites to ensure patient safety. Evidence of air or fluid
density in the interpleural space is diagnostic for pneumothorax or hydrothorax, respectively.
Differential diagnosis: Any fluid or air accumulation in the interplerual space causing severe
dyspnea is a potential candidate for chest drain placement and management.
Medical management:
Pre-examination management: Patients can have a significant amount of pulmonary
atelectasis and ventilatory compromise, yet appear relatively normal. However, the least
amount of stress (i.e. physical examination, chest radiographs, ultrasound) can rapidly push
them into a respiratory decompensation. It is important to handle dyspneic animals with
minimal stress. Generally, a needle thoracentesis can be performed to relieve the immediate
respiratory distress. See the DVD for a detailed video description of performing a needle
thoracentesis. Supplemental oxygen should be provided with a mask during the thoracentesis
procedure. Once the majority of fluid has been removed and the patient is relieved of its lifethreatening dyspnea further workup can commence and, if indicated, an indwelling chest drain
can be inserted.
Surgical treatment: The objective of chest drain placement is to provide an avenue for
removal of contents (i.e., air, fluid) that have accumulated in the interpleural space.
Preoperative management: Supplemental oxygen should be provided with a mask,
and needle thoracentesis performed to remove as much air or fluid as possible. Once the
majority of air or fluid has been removed and the patient is relieved of its life-threatening
dyspnea, anesthetic management can be considered.
Anesthesia: Chest drain placement is an easy and quick procedure; local or general
anesthesia may be considered. General anesthesia offers a more controlled
situation; intubation and gentle positive pressure ventilation are then available to expand
constricted or atelectatic lung lobes.
Surgical anatomy: The lung surfaces are covered with visceral pleura and the
thoracic walls with parietal pleura. The parietal and visceral surfaces are held in intimate
contact by negative pressure coaptation and fluid exchange.
Positioning: Patients are positioned in lateral recumbancy with the most affected
hemithorax uppermost.
Surgical technique: See the DVD for a detailed video description of chest drain
placement. The surgical site is clipped and aseptically prepared. A stab incision is made over
the 9th or 10th intercostal space. A subcutaneous tunnel directed cranioventral is made over
two intercostal spaces with the aid of a Kelly or Crille hemostat. A second hemostat is
clamped at the tip of the drain, or a long metal stylet is placed in the lumen of the drain. The
hemostat or stylet is used to place the drain in the tunnel previously dissected. The hemostat
or stylet and drain are then gently punctured through the intercostal muscles of the 7th
intercostal space and into the thoracic cavity. The intercostal vessels located on the caudal
aspect of the rib are avoided. If a hemostatic forceps is used, once the drain enters the
thoracic cavity, the hemostat is turned 180° so the point of the hemostat is against parietal
pleura; not visceral pleura. The drain is then gently passed in a cranioventral direction until
about 4 to 6 inches are within the pleural cavity. The tube will usually make a gentle curve and
rest on the ventral thoracic floor. Generally, sterile, disposable rubber feeding tubes of size
#14 - 20 French can be used. These tubes have a large enough inside diameter to preclude
obstruction with exudate, yet soft enough to be nonirritating to the pleural surfaces. All
fenestrations in the chest tube must be within the chest cavity to prevent iatrogenic
pneumothorax or leakage of pleural contents into the subcutaneous space. Several simple
interrupted sutures are placed to close the skin snugly around the tube. A Chinese finger-trap
friction suture is used to secure the tube to the patient. A deep simple interrupted suture is
placed in the skin and around the subcutaneous portion of the chest drain to incorporate
lattisamus dorsi muscle, and exited on the opposite side of the tube. This suture helps ensure
a air tight and water tight seal around the exit point of the chest drain.
Suture material/special instruments: #14 to 20 French silastic or red rubber feeding tubes,
pointed stylet to fit in tube lumen
Postoperative care and assessment: An antibiotic ointment is applied to the skin incision
and a comfortable bandage applied around the chest to secure and cover the tubing. Initially,
all fluid or air is withdrawn from the chest. Assisted respiration is then administered to expand
the lungs. In cases with constrictive pleuritis, full expansion cannot be achieved initially. After
all fluid is aspirated, radiographs are taken to confirm proper drain placement and possibly
provide further evidence of etiology (i.e. congestive heart failure, foreign bodies, neoplasia).
Kinks in the tubing may be seen on radiographs and can be corrected by gently maneuvering
the tube in and out of the chest. When not in use, the tubing should be double-clamped and a
sterile 3 cc syringe taped to the end. In addition, all tube connections should be reinforced
using orthopedic wire to engage all parts that could potentially be pulled apart by animal or
man. Here is an illustration of how the author secures all tube connections. All drain tubing is
then covered with the bandage to insure a closed system.
Tube removal: Tube removal is dependent upon the change in volume and character
(i.e., cytology) of the fluid over a period of time. Generally, as the fluid volume decreases and
the cytology is consistent with the irritation caused by the presence of the drain, tube removal
can commence. A gauze sponge with an oil base ointment is placed over the exit wound, and
the tube gently pulled. The gauze sponge remains on the wound to help seal against possible
leaks. A bandage is placed to hold the gauze sponge in place. The bandage can be removed
in 3 to 4 days.
Prognosis: The short term prognosis for patients that require chest drain placement is
generally favorable. If the preoperative management is performed as directed above, drain
placement should be successful and will aid in determining the ultimate cause of the pleural
pathology. The long term prognosis is dependent upon the underlying disorder.
Esophagostomy Feeding Tube Placement in the Cat
surgical procedure on DVD, go to www.videovet.org or contact [email protected] .
Key Points
• feeding tubes should not pass the LES
• “if the gut works, use it”
• learn how to do a Chinese finger trap friction suture
• keep a column of water in the tube between feedings
As a general rule, the closer one comes to the oral route of food intake and digestion, the
more efficient is the assimilation and digestion of nutrients and the greater the flexibility in
formula composition. Conversely, the further aboral one gets, the less efficient is the
assimilation and digestion of nutrients and greater care must be taken when choosing
formula composition. Route of administration also dictates feeding tube diameter; tube
diameter in turn dictates usable feeding formulas due to varying formula viscosity and
particulate matter size. The most common routes of administration for enteral
hyperalimentation include oral, nasoesophageal, esophagostomy, gastrostomy, and
jejunostomy. Techniques for placement of an esophagostomy feeding tube will be presented.
Esophagostomy
Indications: Esophagostomy tube feeding is indicated in anorexic patients with disorders of the oral cavity or pharynx, or anorexic patients with a functional gastrointestinal tract
distal to the esophagus.
Contraindications: Esophagostomy tube placement is contraindicated in patients
with a primary or secondary esophageal disorder (e.g., esophageal stricture, after
esophageal foreign body removal or esophageal surgery, esophagitis, megaesophagus) and
patients with a history of vomiting.
Advantages: Advantages of esophagostomy tube feeding include ease of tube
placement, tubes are well tolerated by the patient, large bore feeding tubes can be used
allowing use of blenderized diets, tube care and feeding is easily performed by the client,
patients can eat and drink around the tube, and tube removal can be performed anytime after
placement. Esophageal tube placement eliminates local pharyngeal irritation, coughing,
laryngospasm, or aspiration occasionally associated with pharyngostomy tubes.
Disadvantage: The major disadvantage of esophagostomy tube is the need for
general anesthesia during placement.
Placement Technique: Provide general anesthesia. Place the patient in right lateral
recumbency with the left side uppermost. The tube can be placed on either the right or left
side of the midcervical region, however the esophagus lies slightly left of midline making left
sided placement more desirable. Aseptically prepare the lateral midcervical area from the
angle of the mandible to the thoracic inlet. Slightly extend the neck and hold the mouth open
with a mouth speculum.
Pre-measure and mark a 20 to 24 French feeding tube for dogs and a 16 – 18 French
feeding tube for cats from the level of the mid-cervical region (i.e., exit point of feeding tube)
to the level of the seventh or eighth intercostal space; ensuring mid- to caudal esophageal
placement. Make certain the tube does not cross the lower esophageal sphincter (LES) as
this may cause sphincteric incompetence, gastric reflux of acid, esophagitis and subsequent
vomiting or regurgitation. Prior to tube placement, enlarge the two lateral openings of the
feeding tube to encourage smoother flow of blended diets.
Eld Esophagostomy Tube Placement Technique
The following technique requires the use of an Eld feeding tube placement device and
is illustrated in the esophagostomy video labeled E-tube. Place the oblique tip of the
instrument shaft through the oral cavity and into the esophagus to the level of the mid
cervical region (i.e., equal distance between the angle of the mandible and thoracic inlet) and
palpate the tip as it bulges the cervical skin. Make a small skin incision over the device tip.
Activate the spring loaded instrument blade until it penetrates esophageal wall, cervical
musculature, subcutaneous tissue and is visible through the skin incision. Carefully enlarge
the incision in the subcutaneous tissue, cervical musculature and esophageal wall with the tip
of a #15 scalpel blade to allow penetration of the instrument shaft. Place a 2-0 Nylon suture
through the side holes of the feeding tube and through the hole in the instrument blade.
Tighten the suture until the tip of the instrument blade and feeding tube tip are in close
apposition. Retract the instrument blade into the instrument shaft so the feeding tube tip just
enters the instrument shaft (i.e., deactivating the instrument blade. Place sterile watersoluble lubricant on the tube and instrument shaft. Retract the instrument and pull the feeding
tube into the oral cavity to its predetermined measurement. Remove the 2-0 Nylon suture to
free the feeding tube from the instrument. Place a stylet through one of the side holes of the
feeding tube and against its tip (do NOT use a stylet when placing an E-tube in cats).
Lubricate the feeding tube and advance it into the esophagus until the entire oral portion of
the tube disappears. Gently retract the stylet from the oral cavity being careful to ensure its
release from the feeding tube. If you encounter resistence and cannot pass the feeding tube
into the esophagus you may have engaged the endotracheal tube. If this happens remove
the feeding tube and replace it under direct visualization. Secure the tube to the cervical skin
with a Chinese finger-trap suture of #1 Novafil.
Curved Carmalt Hemostate Technque
Instead of the Eld device a curved Carmalt hemostat can be used to place an
esophagostomy feeding tube. Patient and feeding tube preparation is identical to that stated
above for the Eld technique.
The curved Carmalt forceps is placed into the cats oral cavity with the curve of the
hemostate directed toward the cervical region. The Carmalt is directed to a point equidistant
between the ramus of the mandible and point of the shoulder midway between the dorsal and
ventral aspect of the neck. The hemostat is pushed laterally so as to make a ‘buldge’ in the
cervical region at the desired exit point described above. A scalpel blade is used to incise
over the tip of the Carmalt until the tip protrudes through the skin. The tip of the feeding tube
is then grasped with the Carmalt hemostat and the tube is exited out through the oral cavity.
The tube is pulled out until the flanged end of the tube just comes in contact with the cervical
skin. The tip of the tube is then turned back on itself, grasped with the Carmalt forceps, and
redirected into the oral cavity of the cat. The tube should remain in the jaws of the Carmalt
hemostat until the tip of the tube is beyond the cervical exit point of the tube. The feeding
tube is then released from the Carmalt and pushed into the esophagus until the tube is in the
mid-esophagus (i.e., 7 or 8th intercostals space). The tube is secured using a Chinese fingertrap friction suture.
Regardless of technique used, the exit point of the tube can be left exposed or
bandaged. A column of water is placed in the tube and the exposed end capped with a 3 cc
syringe; this prevents intake of air, reflux of esophageal contents, and occlusion of the tube
by diet. Most patients tolerate the tube without the need of an Elizabethan collar.
Esophagostomy tubes can be removed immediately after placement or left in place for
several weeks to months. Care of the tube exit site may require periodic cleansing with an
antiseptic solution. Tube removal is performed by cutting the finger- trap suture and gently
pulling the tube. No further exit wound care is necessary; the hole seals in one or two days
and heals by 7 - 10 days.
Complications: Complications associated with esophagostomy tube placement include early
removal by the patient or vomiting the tube No significant long-term complications have been
reported (e.g., esophagitis, esophageal stricture, esophageal diverticulum, or subcutaneous
cervical cellulitis). Reflux esophagitis can occur from improper tube placement (i.e., through
the lower esophageal sphincter) or esophageal irritation from the tube itself. Mid-esophageal
placement of silicone rubber tubes greatly reduces the incidence of esophageal injury and
eliminates reflux esophagitis.
SURGICAL MANAGEMENT OF GDV
Howard B. Seim III DVM, DACVS
If you would like a copy of this surgical procedure on DVD go to www.videovet.org.
Key Points
• Survival is generally determined by early and appropriate presurgical management
• Patients referred for surgery should be decompressed prior to referral with continued
decompression provided during transport
• Incisional gastropexy results in a fast, easy, permanent adhesion
• Ventricular tachycardia is a common postoperative complication
• Gastric necrosis signals an unfavourable prognosis
Introduction: Patients with GDV are considered critical care cases; every minute of
presurgical treatment is vital to a successful outcome. Survival is generally determined by
early and appropriate presurgical management; not surgery. Efficient presurgical treatment
usually involves a minimum of two people. Gastric decompression and shock therapy should
be done simultaneously. If this is not possible; decompression should be performed first. It is
stated that gastric decompression is the single most important factor in reversing
cardiovascular deficits in patients with GDV.
Decompression: Generally, orogastric intubation can successfully be performed in 80 - 90%
of GDV patients. Decompression via flank needle puncture should be attempted in cases
difficult to intubate or severely depressed metabolically deranged patients.
Technique: The stomach tube is measured to the last rib and marked with a piece of tape.
A stiff foal or mare stomach tube with a smooth beveled tip works best (having several
diameter and stiffness tubes is ideal). Apply adequate lubrication to the tube. Place a
functional mouth speculum; generally a roll of 2” tape secured in the mouth with tape
encircling the muzzle. As the stomach tube is passed, you will generally meet resistance at
the esophageal-stomach junction. Pass the tube firmly in a twisting manner to pass the lower
esophageal sphincter.
If unsuccessful, place the patient in various positions and attempt to pass the tube
(i.e., elevate animal at 45 degree angle with rear feet on floor and forefeet on table, right
lateral recumbancy, and left lateral recumbancy). This movement may encourage the
stomach to rotate enough to allow tube passage. Be careful not to position the patient in
dorsal recumbancy as this will increase abdominal visceral pressure on the caudal vena cava
and may exacerbate signs of shock.
If still unsuccessful, try different diameter tubes; try a smaller diameter, more flexible
tube and proceed as described above.
If still unsuccessful, attempt to remove some of the air in the stomach by placing an l8
gauge needle at the point of distention in the right flank region. Ping the area to make sure
the spleen is not under the proposed trocarization site. After trocar decompression, attempt
to pass the stomach tube as described above.
If still unsuccessful, sedate the dog with a narcotic (e.g., Oxymorphone) and try to
pass the tube again. Mild sedation is recommended if the patient strongly resists physical
restraint.
Success in passing a stomach tube depends on the skill of the operator and available
assistants.
If you are successful at passing a stomach tube, but plan to refer the patient to a
referral surgical center for gastropexy, transport the patient with the tube remaining in the
stomach (i.e., taped to the mouth) or bring the tube out through a pharyngostomy incision or
place a nasogastric tube.
If a stomach tube was successfully passed, stomach contents should be evaluated
for color and presence or absence of necrotic looking gastric mucosa. This may give an
impression of gastric viability.
Fluids: Shock dosage of polyionic isotonic fluid is carefully administered to expand the
vascular compartment. Patients are frequently monitored during fluid administration to help
determine ultimate fluid rate and amount. One or two indwelling cephalic catheters are
placed.
Referral: If you are successful at passing a stomach tube, but plan to refer the patient to a
referral surgical center for gastropexy, transport the patient with the tube remaining in the
stomach (i.e., taped to the mouth) or bring the tube out through a pharyngostomy as
described below.
Pharyangostomy placement:
a. Orally palpate the fossa lateral to the hyoid apparatus until a lateral bulge is seen
b. Make a small skin incision over the bulge and press a curved forceps (substitute for finger)
through the soft tissues and skin incision.
c. Pull the stomach tube through the incision with curved forceps; then pass the tube over the
arytenoid cartilages, down the esophagus, and into the stomach (measure to the 13th rib).
Disadvantages include: heavy sedation or general anesthesia is necessary for placement of
tube.
Rarely a temporary gastrostomy may need to be performed. The patient is placed in left
lateral recumbancy with the right flank area clipped and surgically prepared. Heavy sedation
and local infiltration of lidocaine or light general anesthesia is performed. A 4 - 5 cm incision
is made in the skin over the point of greatest gastric distention (generally 1 - 2 cm caudal to
the 13th rib and 2 - 3 cm distal to the transverse processes of the lumbar vertebrae). A grid
technique is used to gain entrance into the peritoneal cavity. Due to severe gastric distention
the stomach wall is pressed against the abdominal wall and easily identified through the flank
incision. The stomach wall is sutured to the skin using a simple continuous pattern with 3-0
Maxon. This is done prior to incising into the stomach lumen. A #11 BP scalpel blade is used
to puncture into the lumen of the stomach. Gas and stomach contents are expelled under
pressure so stand back! The gastric mucosa is evaluated for viability. Disadvantages of
gastrostomy include: the stomach is sutured in its rotated position and more time is required
when definitive surgical treatment is performed due to the necessity of closing the
gastrostomy.
Successful stomach tube placement: Once the stomach tube has been passed into the
stomach or gastrostomy performed, the stomach is lavaged with warm water. If a stomach
tube was successfully passed, the stomach contents should be evaluated for color and
presence or absence of necrotic gastric mucosa. This may give an impression of gastric
viability.
Surgical Treatment: Surgical procedures utilized in the treatment of gastric dilatation-volvulus can be divided into two categories; 1) immediate decompression and 2)
therapeutic gastropexy. Immediate decompression is performed with a successfully passed
stomach tube secured to the patient or temporary gastrostomy as described above.
Therapeutic or prophylactic gastropexy techniques are described below.
Gastric repositioning: Anatomic repositioning of the stomach is necessary to perform prior
to permanent gastropexy. Repositioning occasionally occurs spontaneously at the time of
gastric decompression. Knowledge of normal anatomy is necessary to understand how
repositioning is performed.
A specific ‘Surgical Plan’ should be in mind before entering the operating room theatre. This
will improve the efficiency of surgery and thus decrease overall surgery time. The ‘authors’
surgical plan is as follows:
Stand on the right side of the patient.
Provide generous abdominal exposure via xyphoid to pubis midline laparotomy.
Remove of all of the falciform ligament to the level of the xyphoid.
Place a 10’’ Balfour self retaining abdominal retractor with full retraction.
Confirm that the omentum is draped over the exposed surface of the stomach
(pathagnomonic for GDV)
Exteriorize the spleen from the abdominal cavity. Evaluate color, texture, blood flow
(splenomegaly is always present and is NOT an indication for splenectomy)
Splenectomy is rarely performed but may be necessary if splenic vessels are infarcted.
If the stomach is full of air or fluid it should be emptied, if possible, prior to attempting
derotation. If the stomach is full of food and several attempts to derotate (see author’s
technique below) are unsuccessful, perform a gastrotomy and manually remove the food
from the stomach lumen. Suture the gastrotomy and attempt derotation again.
Attempt derotation by:
Standing on the patients’ right side, first reach your right hand across the abdomen and place
it between the left body wall and dilated stomach.
Slide your right hand along the sublumbar body wall and grasp the deep (dorsal) aspect of
the stomach.
Next, place the open palm of your left hand on the exposed surface of the right side of the
dilated stomach.
Using both hands simultaneously, pull the deep part of the stomach with your right hand to
begin derotation whilst you push the right surface of the stomach down toward the patients
sublumbar body wall with your left hand. This maneuver will be successful in the majority of
cases.
See this maneuver performed on the Emergency Surgery I, Gastrointestinal Surgery I, and
Soft Tissue Surgery II DVD’s available at www.videovet.org.
Once the stomach is derotated, evaluate the stomach for evidence of viability abnormalities
(particularly the greater curvature and fundus) and for evidence of gastric motility.
Commence your gastropexy procedure.
Incisional gastropexy: This technique is based on the construction of a seromuscular antral
flap attached to a incised segment of transversus abdominus muscle. Prior to selecting the
location on the transversus abdominus m for gastropexy, visualize the diaphragmatic muscle
fibers as they radiate into the abdominal cavity and attach near the costal arch. It is important
that the gastropexy site be distant from the diaphragm muscle insertion. In addition, it is
important to locate the ideal position for the gastric antral incision. The incision is located
equidistant between the pylorus and gastric incisure and equidistant between the greater
curvature and lesser curvature. A 3-4 cm incision is made in the antral portion of the
stomach. Once the antral incision has been made, the bleeding surface of the antrum is
brought to the right body wall. With the stomach in a normal position, the bleeding antral
surface is touched to the peritoneal wall approximately 2-3 cm deep to the abdominal wall
incision and caudal to the insertion of the diaphragm. A blood mark is created on the
peritoneum at this proposed location. This will be the site for the permanent gastropexy. The
peritoneum and transverses abdominus muscle are then incised creating a mirror image
defect of the stomach incision. The incisional defect in the stomach is then sutured to the
incisional defect in the abdominal wall. The defects are sutured in two layers using a simple
continuous pattern with 2-0 or 3-0 monofilament or multifilament synthetic absorbable suture.
Belt Loop Gastropexy: This technique is based on the construction of a sero-muscular
antral flap attached around a segment of transversus abdominus muscle. A horseshoe
shaped incision is made in the serosal layer of the antral portion of the stomach with its base
at the greater curvature. The sero-muscular portion of the stomach is identified by grasping
full thickness antral wall between the thumb and index finger and “slipping” the mucosal and
submucosal layers away so only the sero-muscular portion of the wall remains between
thumb and finger. The sero-muscular layer is incised with scissors and the horseshoe
shaped sero-muscular antral flap is dissected and elevated of the submucosal layer. The
stomach is replaced in the abdominal cavity in normal position and the sero-muscular flap
lined up with the transversus abdominus muscle. Once this optimal location is discovered,
two longitudinal incisions (along the fibers of the transversus m.) are made in the transversus
abdominus m. The segment of muscle between the incisions is undermined. The seromuscular flap from the stomach (i.e., belt) is passed through the transversus abdominus m.
(i.e., loop) and sutured to itself to complete the “Belt-Loop” gastropexy. 2-0 or 3-0
monofilament absorbable synthetic suture in a simple interrupted or continuous pattern is
used to secure the flap in place. Advantages of belt loop gastropexy include: it is relatively
easy to perform alone and in the middle of the night, it can be performed quickly, and it is an
effective means of permanent gastropexy.
Postoperative management
In most cases 3 to 4 days of intensive monitoring is necessary for the successful
management of GDV patients. Postoperative considerations are listed below:
a. Shock is a postoperative possibility and the patient should be monitored and treated
accordingly.
b. Patients are generally held off food and water for 24 hours following surgery. During this
time maintenance fluids should be supplied using polyionic isotonic crystalloid fluid. Vomiting
may occur following surgery; the NPO period should be extended accordingly. Gastritis and
gastric motility disorder may be seen in post op GDV patients.
c. After 24 hours of no vomiting, oral alimentation should begin gradually with
a sequence of ice cubes, water, and finally canned dog food. This should occur over a 2-3
day period.
d. Antibiotics should be continued for 7 - 10 days.
e. Routine surgical complications such as infection, dehiscence, seroma, etc. should be
watched for and treated accordingly.
f. EKG monitoring: the most common severe postoperative complication is cardiac
arrhythmia. Approximately 75% of GDV patients will develop arrhythmia’s in the immediate
postoperative period. Arrhythmia’s can be present at the initial time of presentation but most
often occur within 24 - 72 hours after surgery. Ventricular premature contractions,
progressing to ventricular tachycardia is most common. Etiology is unknown but shock,
hypoxia, acid base alterations, endotoxins, myocardial depressant factor (MDF), reperfusion
injury, release of free radicals, and hypokalemia have been identified. Occurrence of a total
body
potassium deficit has been proposed. Etiology of the hypokalemia includes
anorexia, vomiting, tremendous outpouring of potassium rich fluids into a dilated stomach,
and use of potassium poor fluids in treatment of shock. For this reason, adding 20-30 mEq
of potassium chloride per liter of maintenance fluids during and after surgery are
recommended.
g. Gastric motility: occasionally GDV patients will develop postoperatove gastric motility
abnormalities. Patients with gastric hypomotility or gastric stasis should be treated with a
motility modifier (i.e., metaclopramide, erythromycin, etc).
PRINCIPLES OF GI SURGERY
surgical procedure on DVD go to www.videovet.org.
Key Points
• Pay attention to basic surgical principles
• Submucosa is the layer of strength
• Use synthetic absorbable suture materials
• Appositional techniques are best
• Identify breakdown via abdominal tap
General principles of small intestinal surgery
The small intestine is a very forgiving organ system when considering surgical intervention. It
has an excellent blood supply with many collateral mesenteric vessels. If the blood supply
can be preserved during surgical manipulations, small intestinal incisions can be expected to
heal rapidly, gaining almost 70% of their original unwounded tensile strength in 14 - 21 days.
It should be remembered that the small intestine is a low pressure conduit system that
contains primarily liquid contents and has a relatively low bacterial content proximal to the
ileocecocolic valve (compared to the colon). These properties make sugical manipulations of
the small intestine predictably successful if basic principles of tissue handling, preservation of
blood supply, and hemostasis are followed.
Principles of intestinal surgery include:
1) Incorporation of the collagen laden submucosal layer in the surgical closure.
2) Minimize trauma and contamination.
3) Maintain good blood supply to the surgical site.
4) Avoid tension across the suture line as this may increase the possibility of leak and/or
breakdown.
5) Pay attention to your established criteria when suturing intestinal defects.
Preoperative preparation
Preoperative assessment should include a thorough historical and physical examination. This
can often be helpful in localizing the problem to an upper versus lower GI obstruction,
complete or partial obstruction, or strangulating versus nonstrangulating obstruction.
Minimum data base should include complete blood count, electrolytes (i.e., sodium,
potassium, chloride), glucose, and BUN. If available, blood gas analysis should be done on
patients with severe vomiting, dehydration, or possible sepsis.
Criteria for Use of Prophylactic or Therapeutic Antibiotics
Prophylactic antibiotics should be considered in the following situations:
1. Old age (e.g., >7 years old), debilitated patient
2. Likely to open devitalized bowel
3. Estimated surgical time greater than 90 minutes
4. “Break” in aseptic surgical technique
Therapeutic antibiotics should be considered in the following situations:
1. Non GI associated infection that cannot be treated prior to surgery (e.g., severe dental
disease, pyoderma)
2. Gross peritoneal contamination at surgery
3. Operation involving strangulation obstruction
4. Operation in patient with existing peritonitis (e.g., gun shot wound to abdomen with bowel
perforation)
5. Reoperation of intestinal surgical breakdown with peritonitis
Operative Considerations
1) Proper “packing off” of the surgical field using moistened laparotomy pads should be
performed around the exteriorized bowell to prevent accidental abdominal contamination
from intestinal contents.
2) Keep abdominal contents warm and moist throughout surgery with a warm, balanced
electrolyte solution.
3) Handling abdominal viscera should be kept to a minimum. Gentle manipulation of
intestine with moistened gloves or stay sutures is helpful in preventing unnecessary tissue
trauma. DeBakey forceps are the most atraumatic forceps for handling abdominal visceral
organs.
4) The collagen laden, tough submucosa is the layer of strength in the small intestine; this
layer must be incorporated into any small intestinal closure (i.e., enterotomy, anastomosis).
5) It may be difficult to visualize the submucosal layer due to mucosal eversion.
Visualization of submucosa may be enhanced if everted mucosa is trimmed away.
6) Intestinal contents should be "milked" away from the anastomosis or enterotomy site.
Intestinal clamps (e.g., Doyen intestinal clamps, Alice tissue forceps with a rubber feeding
tube interposed, hair clips, or Penrose drains) may be used to prevent intestinal contents
from contaminating the surgical site whilst manipulating intestine during anastomosis or
enterotomy.
7) The enterotomy or anastomosis should be irrigated prior to its return to the abdominal
cavity and instruments and gloves changed prior to abdominal closure.
8) Abdominal lavage with 2-3 liters of body temperature, sterile, physiologic saline solution
should be accomplished prior to closure. The objectives of repeated abdominal lavage
include dilution of bacteria and endotoxin and mechanical removal of fibrin and necrotic
debris. The fluid of choice is body temperature, sterile, physiologic saline solution with no
additives (i.e. betadine solution, chlorhexidine, antibiotics, etc). Lavage solution is poured into
the abdominal cavity using a sterile stainless steel bowl, the abdominal viscera gently
aggitated, and fluid and debris suctioned out with a suction device and a sump suction tip.
Suture Material
Absorbable suture
Catgut. Catgut is NOT recommended in contaminated, infected, hypoproteinemic, or
debilitated cachexic patients. Its unpredictable absorption and rapid loss of tensile strength in
such situations may result in an unacceptably high number of anastomotic leaks and /or
breakdowns. Use of catgut suture in gastrointestinal surgery is not recommended.
Dexon, Polysorb, and Vicryl. Synthetic absorbable braided suture (i.e., polyglactin, polyglycolic acid) have become very popular. The braided nature however does result in
increased tissue drag and difficult knotting ability.
Biosyn and Monocryl. These sutures have similar properties to Dexon, Polysorb and Vicryl
however they are monofilament. They were developed to overcome the problem of tissue
drag and knot slipping found in the braided synthetic absorbables. Their predictable
hydrolytic absorption is unaffected by their immediate environment (i.e., infection, contamination, hypoproteinemia). They retain high tensile strength for a long period of time (2-3
weeks) and have very good handling characteristics. These suture materials are ideal for use
in gastrointestinal surgery. These sutures are the authors choice for gastrointestinal surgery.
PDS and Maxon. PDS and Maxon, are synthetic absorbable monofilament suture materials
with similar properties to that of Dexon and Vicryl. They have been shown to retain
approximately 70% of their tensile strength at 3-4 weeks, and are absorbed by hydrolysis
(unaffected by infection, contamination, hypoproteinemia). These suture materials are ideal
for use in gastrointestinal surgery. Possible disadvantages include stiffness, a tendency to
kink and prolonged absorbtion time.
Nonabsorbable suture
Nylon, Polypropylene, Polybutester. Monofilament, nonabsorbables are excellent suture
materials for use in contaminated or infected surgical sites. They have a high tensile
strength, are relatively inert in tissue, noncapillary, and do not act as a nidus for infection.
These materials pass through tissue with essentially no tissue drag and have excellent knot
tying security at sizes 3-0 to 5-0. For their properties, effectiveness, and cost, these are the
author's nonabsorbable sutures of choice for intestinal anastomosis and enterotomy closure.
Possible disadvantage of these materials is their memory.
Silk, Mersilene, Bronamid, Vetafil. In general, stay away from burying multifilament or braided
nonabsorbable suture material. These sutures may harbor infection for years and may result
in suture related abdominal abscesses or draining tracts. They should never be used in
gastrointestinal surgery.
Suture size
For the majority of small intestinal surgical procedures in dogs, 3-0 or 4-0 size suture material
is adequate; in cats, size 4-0 or 5-0 is recommended. The tensile strength of this size suture
is greater than the tensile strength of the tissues that are being sutured (i.e., intestinal wall).
Larger size suture may contribute to anastomotic failure by increased trauma to tissues and
its effect on the blood supply of tissue margins.
Needles
Swaged-on "atraumatic" reversed cutting, narrow taper point, or fine taper-cut needles can all
be used for gastrointestinal surgery. The author prefers a narrow taper point needle.
Suture Placement
When suturing intestine, sutures should be placed 3 - 4 mm from the cut edge of the intestine
and no more than 2 - 3 mm apart. It is important to recognize everted mucosa and be sure
the 3 - 4 mm bite in the intestinal wall is not just in mucosa but engages all layers of the
intestinal wall. Measure your intestinal wall bite from the cut edge of the serosa.
Suture Patterns
There is considerable controversy regarding specific suture pattern for use in small intestinal
surgery. Everting, inverting, and appositional suture patterns have been used experimentally
and clinically for suturing enterotomies and anastomoses. Appositional patterns are
recommended as they cause little lumen compromise postoperatively.
Everting: Everting patterns (i.e., horizontal mattress) have been shown to encourage
adhesions and result in lumen stenosis. This technique is NOT recommended. The everting
technique is not to be confused with the mild eversion of mucosa that occurs in the
appositional techniques described below.
Figure%2015.pdf
Inverting: In small animals adequate lumen diameter is an important consideration with any
technique. Inverting patterns result in substantial lumen compromise of the small intestine
and are NOT recommended in dogs and cats.
Apposition: Anatomic apposition of individual layers of the bowel wall (i.e., mucosa,
submucosa, muscularis, and serosa) result in primary intestinal healing. This technique is
superior to inverting or everting techniques because apposition of intestinal margins
eliminates lumen compromise. This is the authors preferred technique for suturing all hollow
viscus organs in the abdominal cavity. Suture patterns of choice include:
Figure% 2017.pdf
1) Simple interrupted apposing. This technique involves suturing all layers of the intestinal
wall and tying the knots on top of the serosa to approximate cut edges . The sutures
should be tied tight enough to effect a watertight seal, yet not so tight as to blanch the tissue
and cause ischemia of intestinal margins. This technique is simple, fast, reliable, and does
not result in lumen compromise.
Figure%2018.pdf
2) Simple continuous apposing. This technique is similar to the simple interrupted
appositional technique however, a continuous suture pattern is used rather than an
interrupted pattern. Advantages include faster anastomosis, equal suture tension over the
entire anastomosis, airtight-watertight seal, and mucosal eversion is minimized.
Commonly performed small intestinal surgical procedures
Key Points
• intestinal sutures should engage at least 3 - 4 mm of submucosa and be no further apart
than 2 - 3 mm
• always handle bowel wall with atraumatic technique
• examine the integrity of your anastomsis visually
• 50 - 60% of the small intestine of dogs and cats can be resected
ENTEROTOMY:
See the DVD for a detailed video description of this technique (www.videovet.org).
An enterotomy incision may be necessary for removal of intraluminal intestinal foreign bodies
(e.g., balls, rocks, toys, linear foreign bodies), intestinal biopsy, exploration of the bile duct
papilla or intestinal lumen, or rarely intestinal decompression. The segment of bowel to be
incised should be removed from the abdominal cavity and packed off with moistened
laparotomy pads. An incision parallel to the long axis of the bowel (i.e., longitudinal) or
perpendicular to the long axis of the bowel (i.e., transverse) may be made on the
antimesenteric border, preferably in healthy bowel (i.e., the aboral side of the foreign body).
Closure is performed using the appositional techniques previously described (i.e., simple
continuous or simple interrupted). Omentum can be placed over the enterotomy, but need
not be sutured.
Transverse closure: If a large full thickness piece of intestine must be excised (i.e., mural
mass) longitudinal closure may result in stenosis. To prevent this, transverse closure of the
linear incision is recommended. This ensures adequate lumen diameter without the need for
intestinal anastomosis.
INTESTINAL ANASTOMOSIS: Intestinal anastomosis is indicated for resection of nonreducible intussusception, necrotic bowel wall secondary to complete intestinal obstruction,
intestinal volvulus, stricture secondary to trauma, linear foreign body with multiple
perforations, and intestinal neoplasia (e.g., leiomyoma, leiomyosarcoma, adenocarcinoma).
After a complete abdominal exploration, the affected length of bowel is delivered from the
peritoneal cavity and isolated with the use of moistened laparotomy pads and crib towels. If
possible, the intestinal anastomosis should be performed on a water resistant surface (e.g.,
plastic drape, crib towel) to prevent ‘strike’ through contamination.
Once the level of resection has been determined, the appropriate mesenteric vessels are
identified and ligated, and the portion of intestine to be resected is isolated by clamping the
bowel at a 60° angle away from the mesenteric border. This angle ensures adequate blood
supply to the antimesenteric border.
Everted mucosa: Occasionally when the segment of intestine to be removed is amputated
mucosa ‘everts’ from the cut edge of the intestinal wall making it difficult to visualize the cut
edge of the serosa. If this occurs it is ‘highly’ recommended to excise the everted mucosa to
enable the surgeon to easily visualize the cut edge of the intestinal serosa. It is vital that the
surgeon engage at least 3 – 4 mm of intestinal wall with each suture to guarantee adequate
bites in the collagen laden submucosa.
Bowel lumen diameters: In cases where the oral end of the bowel is dilated and the aboral
end is normal size, several options exist to create intestinal lumens of equal diameter:
Figure% 2024.pdf
1) Increase the angle of resection on the smaller diameter segment of bowel (i.e., aboral
segment). This will increase the orifice size by 5-10 mm depending upon bowel diameter
(e.g., dog vs cat).
2) In larger lumen size discrepancies the antimesenteric border of the smaller diameter
stoma can be incised longitudinally to enlarge the lumen diameter.
3) An end-to-side anastomosis can be performed by closing the larger diameter stoma of the
intestinal resection with a single layer continuous apposing suture pattern then anastomosing
the smaller diameter segment of bowel to an appropriate size enterotomy made in the
antimesenteric border of the larger diameter segment of bowel.
4) The larger diameter segment of bowel can be made smaller in diameter by suturing its cut
edge until its lumen is equal in size to the smaller diameter intestine (this technique is often
used for subtotal colectomy in cats).
Figure% 2024.pdf
Figure% 2025.pdf
Figure% 2026.pdf
Intestinal Anastomosis Technique:
When suturing an anastomosis, atraumatic handling of bowel wall and perfect anatomic
apposition of incised margins is important. It is recommended to begin suturing at the
mesenteric border as this allows adequate visualization of mesenteric vessels and helps
prevent encircling these vessels when placing the first few sutures. Any of the appositional
suture patterns previously described (i.e., simple continuous or interrupted) will result in a
high success rate, both in the short-term (i.e., leakage, breakdown) and long-term (i.e.,
stricture, stenosis).
The following tips may prove helpful when performing an intestinal anastomosis (see the
anastomosis video clip at www.videovet.org for detailed description of the surgery tips below:
1) First, place a stay suture to hold the mesenteric border of each segment of bowel in
apposition. Tie this suture, leave the ends long, and place a hemostat on the suture end
without the needle.
2) Place a second stay suture in the antimesenteric borders of each segment to be sutured to
bring the ends of the intestinal segments into apposition. Place a hemostat on the ends of
this suture.
3) Place gentle traction on the mesenteric and antimesenteric stay sutures to bring the two
intestinal segments into apposition.
4) Using the needled segment of suture from the mesenteric stay suture, begin a simple
continuous appositional anastomosis being careful to get a 3 - 4 mm bite in the submucosa
and placing each suture no more than 2 - 3 mm apart (2 mm apart in cats). When the
anastomosis is complete, tie the suture to the mesenteric stay suture.
5) If a simple interrupted apposing suture pattern is used, be careful to get a 3 - 4 mm bite in
the submucosa and place each suture no more than 2 - 3 mm apart.
6) Evaluate the integrity of the anastomosis. The author’s preference for evaluating the
integrity of anastomotic closure is to visually examine each suture to be certain that suture
placement is no more than 2 - 3 mm apart and that each suture has a 3 mm bite in the
submucosa.
Postoperative care
Intravenous fluids to maintain hydration and ensure renal function are continued
postoperatively, until the patient begins to eat and drink. Intravenous fluids should then be
tapered over a 24 to 48 hour period.
Systemic antibiotics are continued postoperatively for 5-7 days; 10 - 14 days in cases with
peritonitis and/or sepsis.
Feeding: Early return to enteral feeding is best for the overall health of the intestine. Feeding
the postoperative gastrointestinal surgical patient is generrally based on the following criteria:
a) preoperative condition of the patient
b) the condition of the bowel at the time of surgery
c) surgical procedure performed (i.e., enterotomy, anastomosis, pylorectomy)
d) presence or absence of peritonitis
e) postoperative condition of the patient.
The earlier patients can be returned to oral alimenation the better.
Complications
The most common postoperative complication of small intestinal surgery is leakage; leak is
either associated with breakdown of the anastomosis or improper surgical technique (i.e.,
improper suture placement, inappropriate suture material, knot failure, sutures to far apart,
inappropriate bite in the collagen laden submucosal layer, suturing nonviable bowel).
A presumptive diagnosis may be accomplished by the following:
1) Body temperature (may be up if acute or down if moribund).
2) Abdominal palpation: periodic, gentle abdominal palpation for pain (gas or fluid?).
3) General attitude (depression-anorexia).
4) Incision: examination of the patients incision for drainage (look at cytology if drainage is
present)
5) CBC: leukocytosis followed by leukopenia (sepsis), or a degenerative left shift may imply
breakdown.
6) Glucose: low glucose generally implies sepsis (this occurs early in sepsis and may be
used as a screening
test).
7) Abdominal radiographs: generally not helpful, they are difficult to critically assess due to
the presence of postoperative air and lavage fluid. It can take 1 - 3 weeks for peritoneal air to
diffuse from the abdominal cavity after routine abdominal surgery. Time variation is
dependant upon the amount of air remaining in the abdominal cavity postoperatively (i.e.,
large deep chested animal vs a small obese animal).
8) Abdominal tap (paracentesis): a four quadrant abdominal tap is accomplished by
aspirating fluid using a 5cc syringe and 20 gauge needle or placing a plastic IV catheter into
the peritoneal cavity and allowing fluid to drip onto a slide. This may be the most sensitive
diagnostic test for determining the presence or absence of intestinal leak.
9) Peritoneal lavage (if paracentesis is not productive): infuse 10-20cc/kg of sterile
physiologic saline solution into the abdominal cavity, then gently palpate the abdomen and
repeat the four quadrant paracentesis. This technique increases the sensitivity of
paracentesis to 90%.
Once fluid has been obtained, a smear should be stained and evaluated microscopically.
Depending upon the cell types seen, a determination of the presence of leakage can be
made.
Below are examples of expected cytology in patients with and without leak.
1) Healthy PMNs with few degenerate PMNs and a moderate number of red blood cells: This
cytology may be expected in any postoperative abdominal procedure (e.g., OHE, abdominal
exploratory, cystotomy). Your index of suspicion for anastomotic breakdown should be low.
However, if clinical signs continue to deteriorate, repeat paracentesis (2 - 3 times daily, if
necessary) to determine the “trend” of the abdominal fluid cytology is recommended.
2) Healthy polymorphonuclear leukocytes with bacteria located intra or extracellularly,
degenerate PMNs with intracellular bacteria, free bacteria, or food particles--imply
breakdown. Exploratory laparotomy is indicated.
In a recent morbidity/mortality study of patients undergoing intestinal surgery it was found
that animals requiring a second abdominal surgery to treat intestinal disorders were less
likely to survive than patients requiring only one laparotomy. Also, the longer it took to
determine whether or not intestinal leakage had occured the less likely the patient would
survive reoperation. The take home message is: pay attention to detail during the first
surgery and if a leak occurs, diagnose it as soon as possible.
Prognosis The overall prognosis for uncomplicated GI surgery is excellent. The surgeon
must pay attention to detail when suturing any hollow viscus organ with liquid contents.
INTESTINAL ANASTOMOSIS
If you would like a copy of this surgical procedure on DVD go to www.videovet.org.
Key Points
• Pay attention to basic surgical principles
• Submucosa is the layer of strength
• Use synthetic absorbable suture materials
• Appositional techniques are best
• Intestinal sutures should engage at least 3 - 4 mm of submucosa
• Intestinal sutures should be no further apart than 2 - 3 mm
• Always handle bowel wall using atraumatic technique
• Examine the integrity of your anastomsis visually
• 50 - 60% of the ‘small intestine’ of dogs and cats can be resected
General principles of small intestinal surgery
1) Incorporation of the collagen laden submucosal layer in the surgical closure.
2) Minimize trauma and contamination.
3) Maintain good blood supply to the surgical site.
4) Avoid tension across the suture line as this may increase the possibility of leak and/or
breakdown.
5) Pay attention to your established criteria when suturing intestinal defects.
Operative Considerations
1) Proper “packing off” of the surgical field using moistened laparotomy pads should be
performed around the exteriorized bowell to prevent accidental abdominal contamination
from intestinal contents.
2) Keep abdominal contents warm and moist throughout surgery with a warm, balanced
electrolyte solution.
3) Handling abdominal viscera should be kept to a minimum. Gentle manipulation of
intestine with moistened gloves or stay sutures is helpful in preventing unnecessary tissue
trauma. DeBakey forceps are the most atraumatic forceps for handling abdominal visceral
organs.
4) The collagen laden, tough submucosa is the layer of strength in the small intestine; this
layer must be incorporated into any small intestinal closure.
5) It may be difficult to visualize the submucosal layer due to mucosal eversion.
Visualization of submucosa may be enhanced if everted mucosa is trimmed away.
6) Intestinal contents should be "milked" away from the anastomosis site. Intestinal clamps
(e.g., Doyen intestinal clampS, Alice tissue forceps with a rubber feeding tube interposed,
hair clips, or Penrose drains) may be used to prevent intestinal contents from contaminating
the surgical site whilst manipulating intestine during anastomosis.
7) The anastomosis should be irrigated prior to its return to the abdominal cavity and
instruments and gloves changed prior to abdominal closure.
8) Abdominal lavage with 2-3 liters of body temperature, sterile, physiologic saline solution
should be accomplished prior to closure. The objectives of repeated abdominal lavage
include dilution of bacteria and endotoxin and mechanical removal of fibrin and necrotic
debris. The fluid of choice is body temperature, sterile, physiologic saline solution with no
additives (i.e. betadine solution, chlorhexidine, antibiotics, etc). Lavage solution is poured into
the abdominal cavity using a sterile stainless steel bowl, the abdominal viscera gently
aggitated, and fluid and debris suctioned out with a suction device and a Poole suction tip.
Injecting antimicrobials or other products into the abdominal cavity is not recommended.
Suture Material
Absorbable suture
Catgut. Catgut is NOT recommended for any visceral organ surgery. Its unpredictable
absorption and rapid loss of tensile strength in such situations may result in an unacceptably
high number of anastomotic leaks and /or breakdowns. Use of catgut suture in
gastrointestinal surgery is not recommended.
Dexon, Polysorb, and Vicryl. Synthetic absorbable braided suture (i.e., polyglactin, polyglycolic acid) have become very popular. The braided nature however does result in
increased tissue drag and difficult knotting ability.
Biosyn and Monocryl. These sutures have similar properties to Dexon, Polysorb and Vicryl
however they are monofilament. They were developed to overcome the problem of tissue
drag and knot slipping found in the braided synthetic absorbables. Their predictable
hydrolytic absorption is unaffected by their immediate environment (i.e., infection, contamination, hypoproteinemia). They retain high tensile strength for a long period of time (2-3
weeks) and have very good handling characteristics. These suture materials are ideal for use
in gastrointestinal surgery. These sutures are the authors choice for gastrointestinal surgery.
PDS and Maxon. PDS and Maxon, are synthetic absorbable monofilament suture materials
with similar properties to that of Dexon and Vicryl. They have been shown to retain
approximately 70% of their tensile strength at 3-4 weeks, and are absorbed by hydrolysis
(unaffected by infection, contamination, hypoproteinemia). These suture materials are ideal
for use in gastrointestinal surgery. Possible disadvantages include stiffness, a tendency to
kink and prolonged absorbtion time.
Nonabsorbable suture
Nylon, Polypropylene. Monofilament, nonabsorbables are excellent suture materials for use
in contaminated or infected surgical sites. They have a high tensile strength, are relatively
inert in tissue, noncapillary, and do not act as a nidus for infection. These materials pass
through tissue with essentially no tissue drag and have excellent knot tying security at sizes
3-0 to 5-0. For their properties, effectiveness, and cost, these are the author's nonabsorbable
sutures of choice for intestinal anastomosis and enterotomy closure. Possible disadvantage
of these materials is their memory.
Silk, Mersilene, Bronamid, Vetafil. In general, stay away from burying multifilament or braided
nonabsorbable suture material. These sutures may harbor infection for years and may result
in suture related abdominal abscesses or draining tracts. They should never be used in
gastrointestinal surgery.
Suture size
For the majority of small intestinal surgical procedures in dogs, 3-0 or 4-0 size suture material
is adequate; in cats, 4-0 is recommended. The tensile strength of this size suture is greater
than the tensile strength of the tissues that are being sutured (i.e., intestinal wall). Larger size
suture may contribute to anastomotic failure by increased trauma to tissues and its effect on
the blood supply of tissue margins.
Needles
Swaged-on "atraumatic" reversed cutting, narrow taper point, or fine taper-cut needles can all
be used for gastrointestinal surgery. The author prefers a narrow taper point needle. Needle
diameter should approach the diameter of the suture.
Suture Placement
When suturing intestine, sutures should be placed 3 - 4 mm from the cut edge of the
intestinal serosa and no more than 2 - 3 mm apart. It is important to recognize everted
mucosa and be sure the 3 - 4 mm bite in the intestinal wall is not just in mucosa but engages
all layers of the intestinal wall. Measure your intestinal wall bite from the cut edge of the
serosa.
Suture Patterns
There is considerable controversy regarding specific suture pattern for use in small intestinal
surgery. Everting, inverting, and appositional suture patterns have been used experimentally
and clinically for suturing enterotomies and anastomoses. Appositional patterns are
recommended as they cause little lumen compromise postoperatively.
Everting: Everting patterns (i.e., horizontal mattress) have been shown to encourage
adhesions and result in lumen stenosis. This technique is NOT recommended. The everting
technique is not to be confused with the mild eversion of mucosa that occurs in the
appositional techniques described below.
Inverting: In small animals adequate lumen diameter is an important consideration with any
technique. Inverting patterns result in substantial lumen compromise of the small intestine
and are NOT recommended in dogs and cats.
Apposition: Anatomic apposition of individual layers of the bowel wall (i.e., mucosa,
submucosa, muscularis, and serosa) result in primary intestinal healing. This technique is
superior to inverting or everting techniques because apposition of intestinal margins
eliminates lumen compromise. This is the authors preferred technique for suturing all hollow
viscus organs in the abdominal cavity. Suture patterns of choice include:
1) Simple interrupted apposing. This technique involves suturing all layers of the intestinal
wall and tying the knots on top of the serosa to approximate cut edges. The sutures should
be tied tight enough to effect a watertight seal, yet not so tight as to blanch the tissue and
cause ischemia of intestinal margins. This technique is simple, fast, reliable, and does not
result in lumen compromise.
2) Simple continuous apposing. This technique is similar to the simple interrupted
appositional technique however, a continuous suture pattern is used rather than an
interrupted pattern. Advantages include faster anastomosis, equal suture tension over the
entire anastomosis, airtight-watertight seal, and mucosal eversion is minimized. This is the
authors preferred suture pattern for suturing all hollow viscus organs in the abdominal cavity.
INTESTINAL ANASTOMOSIS: Intestinal anastomosis is indicated for resection of nonreducible
intussusception, necrotic bowel wall secondary to complete intestinal obstruction, intestinal volvulus,
stricture secondary to trauma, linear foreign body with multiple perforations, and intestinal neoplasia
(e.g., leiomyoma, leiomyosarcoma, adenocarcinoma).
After a complete abdominal exploration, the affected length of bowel is delivered from the peritoneal
cavity and isolated with the use of moistened laparotomy pads and crib towels. If possible, the
intestinal anastomosis should be performed on a water resistant surface (e.g., plastic drape, crib
towel) to prevent ‘strike’ through contamination.
Once the level of resection has been determined, the appropriate mesenteric vessels are identified
and ligated, and the portion of intestine to be resected is isolated by clamping the bowel at a 60°
angle away from the mesenteric border. This angle ensures adequate blood supply to the
antimesenteric border.
Everted mucosa: Occasionally when the segment of intestine to be removed is amputated mucosa
‘everts’ from the cut edge of the intestinal wall making it difficult to visualize the cut edge of the
serosa. If this occurs it is ‘highly’ recommended to excise the everted mucosa to enable the surgeon
to easily visualize the cut edge of the intestinal serosa. It is vital that the surgeon engage at least 3 –
4 mm of intestinal wall with each suture to guarantee adequate bites in the collagen laden
submucosa.
Bowel lumen diameters: In cases where the oral end of the bowel is dilated and the aboral end is
normal size, several options exist to create intestinal lumens of equal diameter:
1) Increase the angle of resection on the smaller diameter segment of bowel (i.e., aboral segment).
This will increase the orifice size by 5-10 mm depending upon bowel diameter (e.g., dog vs cat).
2) In larger lumen size discrepancies the antimesenteric border of the smaller diameter stoma can be
incised longitudinally to enlarge the lumen diameter.
3) An end-to-side anastomosis can be performed by closing the larger diameter stoma of the intestinal
resection with a single layer continuous apposing suture pattern then anastomosing the smaller
diameter segment of bowel to an appropriate size enterotomy made in the antimesenteric border of
the larger diameter segment of bowel.
4) The larger diameter segment of bowel can be made smaller in diameter by suturing its cut edge
until its lumen is equal in size to the smaller diameter intestine (this technique is often used for
subtotal colectomy in cats).
Intestinal Anastomosis Technique:
When suturing an anastomosis, atraumatic handling of bowel wall and perfect anatomic apposition of
incised margins is important. It is recommended to begin suturing at the mesenteric border as this allows adequate visualization of mesenteric vessels and helps prevent encircling these vessels when
placing the first few sutures. Any of the appositional suture patterns previously described (i.e., simple
continuous or interrupted) will result in a high success rate, both in the short-term (i.e., leakage,
breakdown) and long-term (i.e., stricture, stenosis).
The following tips may prove helpful when performing an intestinal anastomosis (see the anastomosis
video clip at www.videovet.org for detailed description of the surgery tips below:
1) First, place a stay suture to hold the mesenteric border of each segment of bowel in apposition. Tie
this suture, leave the ends long, and place a hemostat on the suture end without the needle.
2) Place a second stay suture in the antimesenteric borders of each segment to be sutured to bring
the ends of the intestinal segments into apposition. Place a hemostat on the ends of this suture.
3) Place gentle traction on the mesenteric and antimesenteric stay sutures to bring the two intestinal
segments into apposition.
4) Using the needled segment of suture from the mesenteric stay suture, begin a simple continuous
appositional anastomosis being careful to get a 3 - 4 mm bite in the submucosa and placing each
suture no more than 2 - 3 mm apart (2 mm apart in cats). When the anastomosis is complete, tie the
suture to the mesenteric stay suture.
5) If a simple interrupted apposing suture pattern is used, be careful to get a 3 - 4 mm bite in the
submucosa and place each suture no more than 2 - 3 mm apart.
6) Evaluate the integrity of the anastomosis. The author’s preference for evaluating the integrity of
anastomotic closure is to visually examine each suture to be certain that suture placement is no
more than 2 - 3 mm apart and that each suture has a 3 mm bite in the submucosa.
Postoperative care
Intravenous fluids to maintain hydration and ensure renal function are continued postoperatively, until
the patient begins to eat and drink. Intravenous fluids should then be tapered over a 24 to 48 hour
period.
Systemic antibiotics are continued postoperatively for 5-7 days; 10 - 14 days in cases with peritonitis
and/or sepsis.
Feeding: Early return to enteral feeding is best for the overall health of the intestine. Feeding the
postoperative gastrointestinal surgical patient is generrally based on the following criteria:
a) preoperative condition of the patient
b) the condition of the bowel at the time of surgery
c) surgical procedure performed (i.e., enterotomy, anastomosis, pylorectomy)
d) presence or absence of peritonitis
e) postoperative condition of the patient.
The earlier patients can be returned to oral alimenation the better.
Complications
i
The most common postoperative complication of small intestinal surgery is leakage; leak is either
associated with breakdown of the anastomosis or improper surgical technique (i.e., improper suture
placement, inappropriate suture material, knot failure, sutures to far apart, inappropriate bite in the
collagen laden submucosal layer, suturing nonviable bowel).
A presumptive diagnosis may be accomplished by the following:
1) Body temperature (may be up if acute or down if moribund).
2) Abdominal palpation: periodic, gentle abdominal palpation for pain (gas or fluid?).
3) General attitude (depression-anorexia).
4) Incision: examination of the patients incision for drainage (look at cytology if drainage is present)
5) CBC: leukocytosis followed by leukopenia (sepsis), or a degenerative left shift may imply
breakdown.
6) Glucose: low glucose generally implies sepsis (this occurs early in sepsis and may be used as a
screening
test).
7) Abdominal radiographs: generally not helpful, they are difficult to critically assess due to the
presence of postoperative air and lavage fluid. It can take 1 - 3 weeks for peritoneal air to diffuse from
the abdominal cavity after routine abdominal surgery. Time variation is dependant upon the amount of
air remaining in the abdominal cavity postoperatively (i.e., large deep chested animal vs a small
obese animal).
8) Abdominal tap (paracentesis): a four quadrant abdominal tap is accomplished by aspirating fluid
using a 5cc syringe and 20 gauge needle or placing a plastic IV catheter into the peritoneal cavity and
allowing fluid to drip onto a slide. This may be the most sensitive diagnostic test for determining the
presence or absence of intestinal leak.
9) Peritoneal lavage (if paracentesis is not productive): infuse 10-20cc/kg of sterile physiologic saline
solution into the abdominal cavity, then gently palpate the abdomen and repeat the four quadrant
paracentesis. This technique increases the sensitivity of paracentesis to 90%.
Once fluid has been obtained, a smear should be stained and evaluated microscopically. Depending
upon the cell types seen, a determination of the presence of leakage can be made.
Below are examples of expected cytology in patients with and without leak.
1) Healthy PMNs with few degenerate PMNs and a moderate number of red blood cells: This cytology
may be expected in any postoperative abdominal procedure (e.g., OHE, abdominal exploratory,
cystotomy). Your index of suspicion for anastomotic breakdown should be low. However, if clinical
signs continue to deteriorate, repeat paracentesis (2 - 3 times daily, if necessary) to determine the
“trend” of the abdominal fluid cytology is recommended.
2) Healthy polymorphonuclear leukocytes with bacteria located intra or extracellularly, degenerate
PMNs with intracellular bacteria, free bacteria, or food particles--imply breakdown. Exploratory
laparotomy is indicated.
In a recent morbidity/mortality study of patients undergoing intestinal surgery it was found that animals
requiring a second abdominal surgery to treat intestinal disorders were less likely to survive than
patients requiring only one laparotomy. Also, the longer it took to determine whether or not intestinal
leakage had occured the less likely the patient would survive reoperation. The take home message
is: pay attention to detail during the first surgery and if a leak occurs, diagnose it and treat it as soon
as possible.
Prognosis The overall prognosis for uncomplicated GI surgery is excellent. The surgeon must pay
attention to detail when suturing any hollow viscus organ with liquid contents.
SPLENECTOMY
Howard B. Seim, III, DVM, DACVS
INDICATIONS
Splenectomy is indicated for removal of splenic neoplasm, rupture, torsion, infarct, abscess and hypersplenism.
PATIENT POSITIONING
The patient is placed in dorsal recumbency for routine celiotomy.
RECOMMENDED INSTRUMENTS
A Balfour self-retaining abdominal retractor is essential to maintain adequate exposure allowing complete
exploration of the abdominal cavity as well as visualization of the splenic blood supply. When large amounts of
blood or fluid are present in the abdominal cavity suction is helpful. It is best to have a variety of sizes of
hemostats available. The author recommends a minimum of 4 medium to large hemostatic forceps (Crile, Kelly
or Carmalt) and 4 – 5 small hemostatic forceps (mosquito).
Ligation of individual blood vessels or clusters of vessels is performed using 3-0 or 4-0 synthetic absorbable
suture material. Common sutures include Biosyn, Monocryl, Dexon, Vicryl, Polysorb, PDS or Maxon.
SURGICAL TECHNIQUE
A ventral midline incision from xyphoid to pubis is made to allow adequate exposure of all abdomen organs.
The spleen is located in the cranial left quadrant of the abdominal cavity just caudal to the greater curvature and
fundus of the stomach. A Balfour self-retaining retractor is positioned to provide exposure of the abdominal
cavity.
The spleen is identified, and gently elevated through the abdominal incision. If the surgeon is dealing with a
bleeding spleen (e.g., hemangiosarcoma) the exteriorized spleen is placed across the body wall to help place
pressure on the splenic blood vessels. In addition, a dry laparotomy pad can be placed directly on the point of
hemorrhage and gentle pressure applied.
Several structures should be identified. The greater curvature of the stomach, dorsal and ventral layers of the
greater omentum, the gastrosplenic ligament and the left limb of the pancreas. Trace the splenic artery and vein
as they course from the dorsal layer of the greater omentum into the gastrosplenic ligament. Identify the left
gastroepiploic artery and vein, the many splenic arterial and venous branches into the hilus of the spleen, the
short gastric vessels and the vessels continuing into the greater omentum.
The spleen receives its blood supply from 3 major sources. Three to five short gastric vessels supply the cranial
aspect of the spleen. The central portion of the spleen is supplied by the major splenic artery and vein and the
caudal pole of the spleen by 4-5 small omental tributaries.
The spleen can safely be removed using a technique requiring only 3 to 4 ligatures. Visualization of these
vessels is accomplished by first elevating the spleen from the abdominal cavity. When attempting to exteriorize
the spleen it is noted that the cranial pole is tethered by the 3 to 4 short gastric vessels. These vessels are
identified and cluster ligated with two encircling ligatures. The vessels are transected between ligatures thus
releasing the tethering effect. The spleen can now be further mobilized from the abdominal cavity allowing easy
exposure of all remaining vessels.
Next the major splenic artery and vein is located and ligated prior to its bifurcation. Care should be taken to
visualize the left limb of the pancreas and make certain it is a safe distance from the proposed ligature site. This
splenic artery and vein are generally double ligated and depending upon size the artery can be transfixed. Finally
the remaining vessels supplying the caudal pole of the spleen are cluster ligated using one or two ligatures.
During the procedure, several points should be remembered:
1) identify the location of the pancreas and do not occlude its blood supply
2) double ligate all major vessels
3) carefully inspect all ligated vessels for evidence of hemorrhage
CLOSURE
The Balfour retractor is removed and the abdominal incision is closed in a routine fashion.
POSTOPERATIVE CONSIDERATIONS
Postoperative care involves monitoring the patient for blood loss that may be encountered should a ligature slip
from the ligated vessels.
VISCERAL ORGAN BIOPSY
If you would like a copy of a video of this surgical technique on DVD, go to www.videovet.org.
Key Points
• Open the abdomen from xyphoid to pubis
• Use the same method of exploration in each case
• When in doubt, biopsy, biopsy, biopsy
• Close the linea alba using a continuous suture pattern
General Considerations and Indications
The systematic, thorough observation and palpation of all abdominal structures is mandatory with any
abdominal exploratory procedure. It is easy to miss a second intestinal foreign body, an area of
metastasis or a ‘second’ tumor if one does not get in the habit of performing a complete exploratory.
An exploratory can be done in any order but it is best to establish a routine and follow it for every
case. With experience the procedure can be completed in less than five minutes. The best way to
recognize an abnormal finding is to know the normal. Take advantage of any laparotomy to observe
normal structure, color, consistency and position of all abdominal organs.
Abdominal exploratory may be indicated in following situations:
Abdominal mass
Undiagnosed GI disorders
Urogenital abnormaities unresponsive to medical management
Abdominal disorders of unknown origin
Penetrating trauma
Acute abdomin
Generalized peritonitis
Diagnosis and treatment of portosystemic shunts
Spleenic abnormalities
Uncontrolled abdominal hemorrhage
Preoperative Considerations
A midline abdominal incision from xiphoid to pubis is the easiest and most versatile approach.
Positioning the patient's head toward the top of the table and tilting the table at a 30° to 40° angle will
facilitate gravitation of abdominal viscera out of the thorax. Rarely is it necessary to extend the
incision into the thorax via a median sternotomy however if your index of suspicion is high that this
may be necessary (e.g., diaphragmatic hernia, chylothorax, porosystemic shunt) the animal should be
properly and adequately prepared.
ABDOMINAL EXPLORATORY TECHNIQUE
Position, Preparation and Draping
The abdomen is always clipped and prepared wider and longer than you may anticipate for a "routine"
procedure. This generally means from cranial to the xyphoid to a point 4-5 cm caudal to the brim of
the pubis and laterally to include the ventral aspect of the abdomen. The animal is placed in dorsal
recumbency in a V-trough with front and hind limbs secured with ropes to the table. If the penis or
prepuce does not need to be accessible during surgery, the prepuce is clipped but not flushed. If the
penis needs to be exposed and handled by the surgeon (lower urinary system exploratory), a
prepucal lavage with a1:50 dilution of betadine solution in sterile saline is performed prior to skin
preparation. An example is when the surgeon feels it is necessary to pass a urinary catheter during
surgery (i.e., urethral and cystic calculi). In this case, the prepuce is clipped then flushed using dilute
Betadine or chlorhexidine prior to the prep. Standard skin preparation is performed.
A ventral midline incision is made from xyphoid to pubis. After identifying the linea alba, a scalpel
blade is used to open the abdominal cavity via a stab incision. Mayo scissors are used to complete
the abdominal incision. Make sure you can see or feel the internal side of the linea so that you do not
damage abdominal viscera during abdominal wall incision. The falciform ligament is excised with
scissors from its attachment to the abdominal wall midline and xyphoid. This will allow better
inspection of viscera, particularly in the cranial quadrant, and facilitate easier closure of the abdomen.
Moistened laparotomy sponges may be placed on the incision if viscera are to be brought out of the
abdomen. All viscera should be kept moistened with saline solution.
Examination of abdominal viscera can be done in any order but it is best to establish a routine and
follow it every time the abdomen is explored. Generally, start with proximal GI tract and move distally,
then liver and pancreas, then urinary tract. Be thorough, and always be gentle when handling tissue.
it is easy to miss a second intestinal foreign body or an area of metastasis if one does not get in the
habit of performing a complete exploratory. With experience, complete exploration can be performed
in less than five minutes. The best way to recognize an abnormal finding is to know the normal. Take
advantage of any laparotomy to observe normal structure, color, consistency and position all of
abdominal organs. You should be able to identify the following structures:
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
16.
17.
Skin, subcutaneous tissue and linea alba
Falciform ligament and fat should be removed with scissors from both sides of the incision, no
ligation is usually necessary
Abdominal aorta and its major branches
Caudal vena cava
Portal vein
Kidneys - artery - frequently multiple; vein - frequently multiple; ureter - note its location at
bladder neck (dorsolateral) and its path along psoas muscles
Liver lobes
Gallbladder
Pancreas (always be gentle handling this organ because you can induce pancreatitis)
-left and right limbs
Diaphragm -left and right crus; aortic hiatus; esophageal hiatus; caval foramen; costal arch
Abdominal esophagus
Stomach - cardia; fundus; body; pylorus (note close relationship of common bile duct and
pancreatic ducts); arterial supply; gastrohepatic ligament
Small bowel - note blood supply to each area
Cecum - note size and consistency, feel ileocecocolic junction
Colon - ascending, transverse and descending portion
Lymph nodes - mesenteric and sublumbar
Omentum and mesentary; greater omentum; lesser omentum; mesoduodenum - used to
displace and pack off cranial portions of abdomen from the right to the left; mesocolon - used to
displace and pack off caudal aspect of abdominal contents from the left to the right
18.
19.
20.
21.
22.
Urinary bladder; ureter entrance on dorsal trigone area; apex and trigone; lateral ligaments
Female; ovary, ovarian bursa, proper ovarian ligament; uterine horn; uterine body; cervix; round
lig; broad lig; suspensory lig (broken down to mobilize ovary during spay)
Male; prostate; ductus deferens (and relation to ureters)
Adrenal glands; phrenicoabdominal arteries and their position in relation to ureters)
Spleen - usually will be very large and turgid as a result of barbiturate anesthesia
Closure
The linea alba is closed with monofilament absorbable or nonabsorbable suture using a simple
continuous pattern. If the abdominal incision was made directly on the midline (i.e., linea alba) closure
requires full thickness bites of the linea alba. If the abdominal incision was slightly off the midline,
suture the rectus sheath only (do not include rectus abdominus muscle or peritoneum). The most
important tissue in the abdominal closure is the collagen dense external rectus sheath. Incorporation
of the internal sheath (i.e., peritoneum) is unnecessary as the peritoneum has very little holding
power. Sutures should engage approximately 5-7 mm of rectus sheath on each side of the incision
line.
Subcutaneous tissues are closed separately with a simple continuous pattern using monofilament or
multifilament synthetic absorbable suture. Tissues should be approximated and not strangulated. In
cats, the subcutaneous closure is not recommended.
Skin is closed with simple interrupted monofilament nonabsorbable skin sutures or a continuous
intradermal suture (i.e., subcuticular).
Postoperative Care
Postsurgical care may include systemic antibiotics, appropriate pain medication, careful monitoring of
the patient's breathing, temperature, and color. Hypothermic patients should be kept in a warming
cage or on a warm water circulating blanket for at least 24 hours. Analgesics may be used to relieve
patient discomfort, however care should be taken to monitor the effects of various analgesic drugs on
respiratory effort.
BIOPSY TECHNIQUES FOR ABDOMINAL ORGANS
A variety of visceral organ biopsy techniques are illustrated on a video DVD available through
VideoVet at www.videovet.org.
Liver Biopsy
Liver biopsy is indicated whenever an abdominal exploratory is being performed in patients thought to
have liver disease or in cases that liver disease was not the primary reason for exploratory but the
liver appears grossly normal.
Liver biopsy is one of the most important diagnostic aids available for evaluation of liver disease.
Samples for cytologic examination may be obtained via percutaneous needle biopsy, laparoscopy, or
exploratory laparotomy. Percutaneous needle biopsy techniques are the most efficient in terms of
time and expense.
Several techniques are available for obtaining liver specimens during exploratory laparotomy. The
simplest method is performed by cutting a strip of liver parenchyma 5 to 6 mm thick along the border
of the liver lobe. Excessive bleeding is rarely a problem with this technique; hemorrhage is controlled
via cautery or direct pressure. Diffuse liver disease must be present if this method is to be diagnostic.
A second technique involves placing an encircling ligature around a pedicle of liver tissue. As the
ligature is tightened, it cuts through the hepatic parenchyma, ligating hepatic vessels and bile ducts.
This technique is widely known as the Guillotine technique. This method requires the presence of
diffuse liver disease to obtain a diagnostic biopsy munless the lesion is present in the distal aspect of
the liver lobe.
A technique that can be used in ‘bulbous’ liver lobes with no convenient edges to biopsy is performed
by penetrating the central portion of the proposed biopsy site with 2-0 or 3-0 suture on a swaged-on
curved taper needle. The suture ends are left long and a mosquito hemostat attached. A second pass
of the suture is made through the same location as the first needle pass. A second stay suture is
made. Each stay suture is tied individually to “cut” through the liver. A “V” wedge is cut through the
liver when both strands of suture have been tied. A number 15 BP scalpel blade or fine Metzenbaum
scissors is used to cut the V-shaped liver biopsy wedge from the sutures.
Another technique for use in patients with diffuse fibrotic liver disorders is performed by penetrating
the affected liver lobe with a straight mosquito hemostat. The hemostat tip is placed on the surface of
the liver lobe to be biopsied and gently plunged through the liver lobe until the tip of the hemostat is
seen penetrating through the opposite side of the liver. The jaws of the hemostat are opened just wide
enough to accept a piece of 2-0 or 3-0 Maxon or Biosyn suture. The suture is doubled on itself, the
loop is passed into the jaws of the hemostats, and the loop pulled through the liver lobe. The exiting
loop is cut leaving two strands of suture coursing through the liver lobe. Each strand is tied
individually to “cut” through the liver. A “V” wedge is cut through the liver when both strands of suture
have been tied. A number 15 BP scalpel blade is used to cut the V-shaped liver biopsy wedge from
the sutures.
Occasionally it may be required to biopsy a small lesion located distant from the liver lobe margin.
This can be accomplished using a 4mm or 6mm ‘sharp’ skin punch biopsy instrument. The skin punch
is placed directly over the lesion on the surface of the liver. With mild downward pressure and a
gentle back and forth twisting motion the punch biopsy instrument cuts a circular hole in the liver thus
engaging a piece of the liver. The punch is then angled to attempt to cut the base of the biopsy
specimen. The punch is removed and either the biopsy specimen comes out with the punch or a
DeBakey forcep may be needed to remove the specimen from its remaining attachment to the liver.
This technique results in a very small biopsy specimen and thus an additional marginal liver biopsy is
performed.
Pancreatic biopsy
The old wives tale stating “don’t touch the pancreas” needs to be put to rest. Gentle manipulation and
biopsy of the pancreas is a predictably successful procedure with almost no incidence of
postoperative pancreatitis.
Biopsy of the pancreas is performed in a similar manner as biopsy of the liver. In patients that have
diffuse pancreatic disease, a segment of the right or left limb of the pancreas is identified. An
encircling ligature of 3-0 Biosyn is placed around the pedicle. As the ligature is tightened, it cuts
through the pancreatic parenchyma, ligating vessels and pancreatic ducts. The distal pedicle of
pancreas is carefully removed with a number 15 BP scalpel blade or metzenbaum scissors. Care is
taken to avoid cutting the suture. If a relatively large portion of pancreas is to be removed (e.g.,
removal of insulinoma), a similar technique is used. In this situation, 2-0 or 3-0 monofilament
nonabsorbable suture should be used.
Stomach and Small Intestine
Patients with chronic vomiting or chronic diarrhea of unknown origin often require gastric and
intestinal biopsies for definitive diagnosis. In many cases, the surgeon will examine the
gastrointestinal tract carefully and conclude that there are no apparent abnormalities. In this situation,
ALWAYS perform gastric and multiple intestinal biopsies (i.e., duodenum, jejunum, ileum). Remember
these words of wisdom when concluding that you have a negative exploratory laparotomy “your eyes
are NOT microscopes”.
Gastric biopsy
The stomach should be visually examined for any obvious abnormalities on the serosal surface. In
addition, the stomach should be carefully palpated to determine if there are mural or mucosal
abnormalities present. In the case of an observed or palpated abnormality, the surgeon should plan
the gastric biopsy to include a portion of the abnormal stomach, the margin of normal and abnormal
stomach, and normal stomach. Full thickness biopsies should always be taken. In the case of diffuse
disease or if an abnormality cannot be located, a 3-4 cm incision should be made in the ventral aspect
of the stomach equidistant from the greater and lesser curvature. Stay sutures are placed at the
midpoint of the incisied edges and the interior of the stomach visually and digitally examined. If a
mucosal abnormality is detected, the area should be biopsied either from inside the stomach of from
the serosal surface directly over the lesion.
Gastric wall incisions (e.g., biopsy, gastrotomy, partial gastrectomy) should be closed with a single
layer, simple continuous or simple interrupted suture pattern being careful to get full thickness bites.
Sutures should be placed no further apart than 3 mm and at least a 4 mm bite of gastric wall is
recommended. Monofilament absorbable suture with a sharp taper or taper-cut (penetrating point)
needle is the authors’ preference.
Small intestinal biopsy
Several techniques can be used to successfully biopsy the intestine. Always remember; FULL
THICKNESS biopsy is mandatory for the pathologist to give you the the most accurate diagnosis.
When taking an intestinal biopsy, the easiest way to guarantee you will get an adequate size, full
thickness piece of intestine is to use a brand new 4mm skin punch biopsy instrument. The skin punch
is placed on the antimesenteric border of the proposed segment of intestine and ‘drilled’ through all
layers of intestine until the biopsy punch can be felt to enter the lumen of the intestine. The skin punch
is removed and the biopsy retreived from the shaft of the skin punch biopsy. This technique is
particularly useful for ileal biopsy as it is easy to biopsy between the mesenteric and antimesenteric
vessels. Transverse closure of the biopsy site is recommended to eliminate the possibility of lumen
compromise. Suture technique is as described above for enterotomy closure. This is the authors'
preferred technique for intestinal biopsy.
An alternate technique for intestinal biopsy is to make a 2-3 mm long incision on the antimesenteric
border of the intestinal segment. A #11 or #15 BP scalpel blade is used to penetrate the intestinal
wall. The blade is withdrawn to create a 2-3 mm long incision. A second parallel incision is made 1 – 2
mm from the original incision. A DeBakey forcep is used to grasp one end of the parallel incisions, a
Metzenbaum scissor is used to cut out the piece of intestine. The surgeon should be careful not to
crush the specimen with forceps. Only handle one end of the specimen whilst excising the biopsy
specimen. If excessive trauma is created during biopsy, the pathologist may not be able to determine
if the pathology is real or surgically created. The excised piece of intestine is examined closely to
ensure that all layers have been included in the specimen. The biopsy site is closed using a simple
interrupted or simple continuous suture pattern. 3-0 or 4-0 monofilament absorbable suture with a
swaged-on sharp taper or taper-cut (penetrating point) needle is recommended. Care is taken to
ensure that at least 3 mm bites are taken into the intestine and the sutures are no more that 2-3 mm
apart.
Biopsy of the duodenum, jejunum, and ileum is recommended whenever a chronic vomiting/diarrhea
patient is explored.
Complications associated with multiple intestinal biopsies are rare. Even patients that present with
protein loosing enteropathy. One study looking at the complication rate of intestinal surgical
procedures in patients with normal protein levels and patients that were hypoproteinemic found no
difference. Complications in patients undergoing intestinal surgica procedures are generally related to
the surgeons technical ability not the patients preoperative status.
Wound Management Secrets
Split-shot Wound Management
Key Points
• Skin has the ability to stretch when placed under mild tension
• Normal wound contraction often stops before wound edges appose.
• Split-shot wound management can be used to encourage skin edges to contract.
If you would like a copy of the illustrated version of these notes on CD and a video of this surgical
procedure on DVD, go to www.ivseminars.com and click VideoVet or contact [email protected].
Indications: Use of various appliances to create tension on the local skin of non-contracting open
wounds is not new. Subcutaneously buried silastic balloons (i.e., skin expanders) injected every 24
hours with varying amounts of saline will stretch local skin and have been used extensively in human
plastic and reconstructive surgery. Skin expanders have also been described for use in veterinary
patients. Skin expansion may be indicated in wounds that have undergone normal wound contraction
without successful wound margin apposition. The most common locations for inappropriate wound
contraction in small animals are extremities, head, and tail.
Applied Anatomy: Skin is made up of several layers that collectively form a complex organ system.
Skin is not capable of regeneration. One method of getting ‘more’ skin for wound coverage is
encouraging local skin to undergo intussusceptive growth. This can be accomplished by applying
tension to local skin around the wound. If tension is constant, skin layers will accommodate the
increase tension by becoming thinner thus allowing the skin to ‘stretch’.
Anesthesia: Patients undergoing split-shot wound management should be placed under general
anesthesia.
Technique: Positioning: Patients are positioned with the wounded area uppermost.
Patient preparation: Wounds identified for split-shot wound management should be treated as
an open wound until there is evidence of a healthy granulation tissue bed. Routine aseptic preparation
of the local skin is performed.
Special instruments and suture: Metallic split-shot (i.e., other than lead) can be purchased at
any local sporting goods or fishing store. Split-shots are placed in a cold sterilization media for an
appropriate time period and thoroughly rinsed prior to use. Monofilament non-absorbable suture with
a swaged-on taper needle, size 00 to #1 depending upon location and size of wound is
recommended. A sterile rubber bumper is fashioned from a feeding tube or catheter.
Split-shot technique: The wound and surrounding skin are prepared for aseptic surgery. Two
bumpers are created by cutting one 1/2 inch piece off the flanged end of a 20 French feeding tube or
catheter. This segment of tube is then split in two.
An appropriate size monofilament nonabsorbable suture is selected. The skin edges are gently
undermined being careful not to trim the wound edge. The swaged-on needle is placed through the
rubber bumper and enters the wound at the commissure. The wound edges are then sutured using a
simple continuous pattern. Care is taken to engage the needle in the tough collagen laden
subcutaneous tissue. Patients with thin subcutaneous tissue (i.e., cats, small dogs, areas of thin skin)
may require penetration of skin instead of subcutaneous tissue. Once the entire length of the wound
has been sutured, the suture is passed out through the skin of the remaining commissure of the
wound. Knots are not tied in either end of the suture.
Gentle traction is placed on the exiting ends of the suture until mild tension is placed on the
wound edges and local skin. A split-shot is placed on each end of the exiting suture against the
bumper. The split-shot is then gently but firmly clamped against the suture; this maintains tension on
the skin edges and local skin. The wound is bandaged, an Elizabethan collar placed, and the patient
confined to a cage. Each day the bandage is removed, the ends of the suture gently pulled and a
split-shot is placed between the bumper and the original split-shot. Daily tension is performed without
the need for general anesthesia or sedation. Skin may be responsive to tension for 7 to 10 days.
When the wound is closed to your satisfaction, the suture and bumpers are removed. The remaining
wound is bandaged only if it requires further protection.
Tie-over Bandage Technique
If you would like a copy of the illustrated version of these notes on CD and a video of this surgical
procedure on DVD, go to www.ivseminars.com and click VideoVet or contact [email protected].
Key Points
• The most important aspects of wound management are debridement, debridement, debridement.
• The solution to pollution is dilution.
• A tie-over bandage can cover the most difficult to bandage wounds.
• A tie-over bandage can help ‘stretch’ local skin.
If you would like an instructive DVD of this topic, go to www.ivseminars.net and click on Video Vet.
WOUND MANAGEMENT: The area should be clipped and cleaned as soon as possible to provide a
clean environment beneath the bandages that will eventually be applied. Sterile, water soluble gel
placed on the wound is a convenient means of temporary wound protection. Dried blood and debris
should be removed from the surrounding skin with antiseptic soap, using care to avoid contact
between the soap and exposed tissues which can result in lipolysis and tissue damage. The primary
goal of wound management is to decrease bacterial numbers and debris and enhance the animal's
defense mechanisms (i.e., debridement). Gross particulate matter, hair, etc. should be removed
manually from the wound. Lavage is beneficial in further decreasing infection-promoting debris and
bacteria. Saline is indisputably the ideal lavage solution, although dilute chlorhexidine (0.05 to
0.005%), or povidone-iodine (0.01%) may be used. The effectiveness of lavage is dependent upon
volume and pressure. Studies have shown that high pressure (25-60 psi) is superior to low pressure
(0.5-5.0 psi) when wounds are only lavaged one time. Medium pressure, which has also been shown
to be beneficial can be generated using an 18 gauge needle and large syringe (35-60 ml). Surgical
debridement of necrotic-appearing tissue and embedded foreign material limits nutrients for bacterial
growth and enhances the animal's local defense mechanisms.
OPEN WOUND MANAGEMENT: Open wound management allows optimal drainage and daily
inspection, debridement and lavage of tissues. Following surgical excision of necrotic tissue, etc.,
continued mechanical debridement can be performed using an adherent dressing (wet-to-dry, dry-todry, or wet-to-wet). Wide-mesh gauze sponges are ideal for adherent bandages. The type of dressing
used depends on wound conditions. Wet-to-dry dressings can be used for wounds with necrotic
tissue, foreign matter and viscous exudate. The wet dressing dilutes the exudate and allows
absorption. As the dressing dries, necrotic tissues adhere to the gauze and are removed with the
bandage. Dry-to-dry dressings have similar indications as wet-to-dry except without the presence of
viscous exudate. Wet-to-wet dressings are indicated when viscous exudate is present without
necrotic tissues. The contact adherent layer should be covered by an absorbent outer layer. Once
necrotic tissues have been removed and granulation tissue begins to form, adherent gauze should be
replaced with nonadherent pads (telfa).
SECOND INTENTION HEALING: Second intention healing occurs by formation of granulation tissue,
wound contraction and epithelialization. The advantages of this process are drainage remains
optimal, wound infections are rare and the time and expense of surgery is avoided. However, second
intention healing may cause disfigurement or loss of function due to wound contracture, and the
epithelium formed may be easily disrupted.
TIE-OVER BANDAGE: Indications: Large surface area wounds (i.e., abdomen, thorax, back, neck)
or wounds in ‘difficult-to-bandage’ areas (i.e., tail, perineum, head, paraprepucial,proximal
extremeties) may not be amenable to routine bandaging techniques. These areas generally lend
themselves nicely to placement of a tie-over-bandage.
Technique: The wound bed is prepared as described above. Several # 0 or #1 monofilament nonabsorbable suture loops are placed in the skin on the periphery of the wound. Loop sutures are
generally placed 360o around the wound and spaced 2 or 3 cm apart. Appropriate wound covering
materials are placed in the wound bed (i.e., wet to dry, gauze, telfa, etc) and a sterile laparotomy pad
placed on top to provide protection to the wound. Several lengths of 1/4 inch or 1/2 inch umbilical tape
are passed through the loops of suture, over the laparotomy pad and through the suture loop on the
opposite side of the wound. The umbilical tape passes over the wound mutiple times to hold the
laparotomy pad in place (an therefore the wound covering materials). Enough traction is placed on the
suture loops to place mild tension on the skin edges of the healing wound. This bandage is easily
removed and replaced for ease of bandage change.
Once the granulation bed is healthy and the wound is considered surgically clean it can be closed
primarily (i.e., delayed primary closure). If there are small defects at the time of suture removal these
can generally heal by second intention.
Wound Management Secrets
Split-shot Wound Management
Key Points
• Skin has the ability to stretch when placed under mild tension
• Normal wound contraction often stops before wound edges appose.
• Split-shot wound management can be used to encourage skin edges to contract.
If you would like a copy of the illustrated version of these notes on CD and a video of
this surgical procedure on DVD, go to www.ivseminars.com and click VideoVet or
contact [email protected].
Indications: Use of various appliances to create tension on the local skin of noncontracting open wounds is not new. Subcutaneously buried silastic balloons (i.e., skin
expanders) injected every 24 hours with varying amounts of saline will stretch local skin
and have been used extensively in human plastic and reconstructive surgery. Skin
expanders have also been described for use in veterinary patients. Skin expansion may
be indicated in wounds that have undergone normal wound contraction without
successful wound margin apposition. The most common locations for inappropriate
wound contraction in small animals are extremities, head, and tail.
Applied Anatomy: Skin is made up of several layers that collectively form a complex
organ system. Skin is not capable of regeneration. One method of getting ‘more’ skin for
wound coverage is encouraging local skin to undergo intussusceptive growth. This can
be accomplished by applying tension to local skin around the wound. If tension is
constant, skin layers will accommodate the increase tension by becoming thinner thus
allowing the skin to ‘stretch’.
Anesthesia: Patients undergoing split-shot wound management should be placed
under general anesthesia.
Technique: Positioning: Patients are positioned with the wounded area uppermost.
Patient preparation: Wounds identified for split-shot wound management should
be treated as an open wound until there is evidence of a healthy granulation tissue bed.
Routine aseptic preparation of the local skin is performed.
Special instruments and suture: Metallic split-shot (i.e., other than lead) can be
purchased at any local sporting goods or fishing store. Split-shots are placed in a cold
sterilization media for an appropriate time period and thoroughly rinsed prior to use.
Monofilament non-absorbable suture with a swaged-on taper needle, size 00 to #1
depending upon location and size of wound is recommended. A sterile rubber bumper is
fashioned from a feeding tube or catheter.
Split-shot technique: The wound and surrounding skin are prepared for aseptic
surgery. Two bumpers are created by cutting one 1/2 inch piece off the flanged end of a
20 French feeding tube or catheter. This segment of tube is then split in two.
An appropriate size monofilament nonabsorbable suture is selected. The skin
edges are gently undermined being careful not to trim the wound edge. The swaged-on
needle is placed through the rubber bumper and enters the wound at the commissure.
The wound edges are then sutured using a simple continuous pattern. Care is taken to
engage the needle in the tough collagen laden subcutaneous tissue. Patients with thin
subcutaneous tissue (i.e., cats, small dogs, areas of thin skin) may require penetration
of skin instead of subcutaneous tissue. Once the entire length of the wound has been
sutured, the suture is passed out through the skin of the remaining commissure of the
wound. Knots are not tied in either end of the suture.
Gentle traction is placed on the exiting ends of the suture until mild tension is
placed on the wound edges and local skin. A split-shot is placed on each end of the
exiting suture against the bumper. The split-shot is then gently but firmly clamped
against the suture; this maintains tension on the skin edges and local skin. The wound
is bandaged, an Elizabethan collar placed, and the patient confined to a cage. Each day
the bandage is removed, the ends of the suture gently pulled and a split-shot is placed
between the bumper and the original split-shot. Daily tension is performed without the
need for general anesthesia or sedation. Skin may be responsive to tension for 7 to 10
days. When the wound is closed to your satisfaction, the suture and bumpers are
removed. The remaining wound is bandaged only if it requires further protection.
Tie-over Bandage Technique
If you would like a copy of the illustrated version of these notes on CD and a video of
this surgical procedure on DVD, go to www.ivseminars.com and click VideoVet or
contact [email protected].
Key Points
• The most important aspects of wound management are debridement, debridement,
debridement.
• The solution to pollution is dilution.
• A tie-over bandage can cover the most difficult to bandage wounds.
• A tie-over bandage can help ‘stretch’ local skin.
If you would like an instructive DVD of this topic, go to www.ivseminars.net and click on
Video Vet.
WOUND MANAGEMENT: The area should be clipped and cleaned as soon as possible
to provide a clean environment beneath the bandages that will eventually be applied.
Sterile, water soluble gel placed on the wound is a convenient means of temporary
wound protection. Dried blood and debris should be removed from the surrounding skin
with antiseptic soap, using care to avoid contact between the soap and exposed tissues
which can result in lipolysis and tissue damage. The primary goal of wound
management is to decrease bacterial numbers and debris and enhance the animal's
defense mechanisms (i.e., debridement). Gross particulate matter, hair, etc. should be
removed manually from the wound. Lavage is beneficial in further decreasing infectionpromoting debris and bacteria. Saline is indisputably the ideal lavage solution, although
dilute chlorhexidine (0.05 to 0.005%), or povidone-iodine (0.01%) may be used. The
effectiveness of lavage is dependent upon volume and pressure. Studies have shown
that high pressure (25-60 psi) is superior to low pressure (0.5-5.0 psi) when wounds are
only lavaged one time. Medium pressure, which has also been shown to be beneficial
can be generated using an 18 gauge needle and large syringe (35-60 ml). Surgical
debridement of necrotic-appearing tissue and embedded foreign material limits nutrients
for bacterial growth and enhances the animal's local defense mechanisms.
OPEN WOUND MANAGEMENT: Open wound management allows optimal drainage
and daily inspection, debridement and lavage of tissues. Following surgical excision of
necrotic tissue, etc., continued mechanical debridement can be performed using an
adherent dressing (wet-to-dry, dry-to-dry, or wet-to-wet). Wide-mesh gauze sponges
are ideal for adherent bandages. The type of dressing used depends on wound
conditions. Wet-to-dry dressings can be used for wounds with necrotic tissue, foreign
matter and viscous exudate. The wet dressing dilutes the exudate and allows
absorption. As the dressing dries, necrotic tissues adhere to the gauze and are
removed with the bandage. Dry-to-dry dressings have similar indications as wet-to-dry
except without the presence of viscous exudate. Wet-to-wet dressings are indicated
when viscous exudate is present without necrotic tissues. The contact adherent layer
should be covered by an absorbent outer layer. Once necrotic tissues have been
removed and granulation tissue begins to form, adherent gauze should be replaced with
nonadherent pads (telfa).
SECOND INTENTION HEALING: Second intention healing occurs by formation of
granulation tissue, wound contraction and epithelialization. The advantages of this
process are drainage remains optimal, wound infections are rare and the time and
expense of surgery is avoided. However, second intention healing may cause
disfigurement or loss of function due to wound contracture, and the epithelium formed
may be easily disrupted.
TIE-OVER BANDAGE: Indications: Large surface area wounds (i.e., abdomen, thorax,
back, neck) or wounds in ‘difficult-to-bandage’ areas (i.e., tail, perineum, head,
paraprepucial,proximal extremeties) may not be amenable to routine bandaging
techniques. These areas generally lend themselves nicely to placement of a tie-overbandage.
Technique: The wound bed is prepared as described above. Several # 0 or #1
monofilament non-absorbable suture loops are placed in the skin on the periphery of the
wound. Loop sutures are generally placed 360o around the wound and spaced 2 or 3
cm apart. Appropriate wound covering materials are placed in the wound bed (i.e., wet
to dry, gauze, telfa, etc) and a sterile laparotomy pad placed on top to provide protection
to the wound. Several lengths of 1/4 inch or 1/2 inch umbilical tape are passed through
the loops of suture, over the laparotomy pad and through the suture loop on the
opposite side of the wound. The umbilical tape passes over the wound mutiple times to
hold the laparotomy pad in place (an therefore the wound covering materials). Enough
traction is placed on the suture loops to place mild tension on the skin edges of the
healing wound. This bandage is easily removed and replaced for ease of bandage
change.
Once the granulation bed is healthy and the wound is considered surgically clean it can
be closed primarily (i.e., delayed primary closure). If there are small defects at the time
of suture removal these can generally heal by second intention.

Soft Tissue - Central Florida Academy of Veterinary Medicine

Transcription

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