I Umbilical Hernia Repair Robert E. Cilley, MD, and Serene Shereef, BS ANATOMY/EMBRYOLOGY
Transcription
I Umbilical Hernia Repair Robert E. Cilley, MD, and Serene Shereef, BS ANATOMY/EMBRYOLOGY
Umbilical Hernia Repair Robert E. Cilley, MD, and Serene Shereef, BS n contrast to the vital role played by the umbilicus in utero, it has minimal physiologic importance after birth. It can be used as a convenient site for vascular access in newborns; neonatologists use umbilical arterial and umbilical venous catheters frequently. The umbilicus can be a portal for infection in newborns (omphalitis). The umbilicus is frequently used as an entry site for laparoscopic procedures. Its psychological importance throughout life has been observed in individuals who have had surgical loss of their umbilicus.1 Persistent umbilical hernias are the most common umbilical problem encountered by surgeons. I NATURAL HISTORY Umbilical hernias are most often noted after separation of the umbilical cord remnant. There are no definitive prospective longitudinal studies of umbilical hernias from birth to adulthood. It is therefore difficult to speculate as to the natural history of this process if hernia repair is withheld. Rupture of the hernia with evisceration is almost unheard of. Incarceration of visceral contents is rare. Most (80%) congenital umbilical hernias close spontaneously within the first 3 years of life. However, umbilical hernias may continue to close into childhood. Hernias with a diameter greater than 1.5 cm are less likely to close on their own. “Proboscoid” hernias that turn inferiorly as they protrude are less likely to resolve spontaneously. Umbilical hernias usually disappear abruptly when the fascial defect can no longer admit visceral contents. After spontaneous closure, the resultant umbilicus usually has a natural concave appearance. Occasionally, retained material results in a protruding umbilical stalk. Small unrepaired umbilical hernias in girls may become symptomatic during pregnancy when the abdominal wall stretches. There is a greater risk of incarceration in adults than in children.2 Although used frequently in the past, topical applications, straps, trusses, and coins do not promote closure of the umbilical ring and may be injurious. From the Department of Surgery, Division of Pediatric Surgery, Pennsylvania State University College of Medicine, Hershey, PA. Address reprint requests to Robert E. Cilley, MD, Division of Pediatric Surgery, Milton S. Hershey Medical Center, 500 University Drive, MC H113, Hershey, PA 17033. © 2005 Elsevier Inc. All rights reserved. 1524-153X/04/0604-0003$30.00/0 doi:10.1053/j.optechgensurg.2004.10.003 244 ANATOMY/EMBRYOLOGY Disorders of the umbilicus are due either to the failure of closure of the umbilical ring or because of the persistence of structures, which usually obliterate before birth. The formation of the umbilicus takes place in early gestation as a result of a fusion of the body stalk containing the umbilical vessels and allantois with the extracoelomic yolk stalk containing the vitelline (omphalomesenteric) duct and vessels. The fetal midgut normally returns to the abdominal cavity by 12 weeks’ gestation, and the abdominal wall closes. The umbilicus closes as mesoderm migrates in to form the abdominal wall. Failure of this closure can lead to an omphalocele, hernia of the umbilical cord, or an umbilical hernia. An umbilical hernia is distinguished from a “hernia of the umbilical cord.” A hernia of the umbilical cord is similar to an omphalocele in that there is a defect in the peritoneum as well as a fascial defect and the viscera herniate into the substance of the cord itself. In a true umbilical hernia, the hernia protrusion is composed of peritoneum adherent to the undersurface of the umbilical skin. The umbilical ring continues to close until birth as the linea alba narrows and the rectus muscles approach the midline. At birth, the contracted umbilical ring is normally reinforced by the round ligament (umbilical vein), urachus, lateral umbilical ligaments (vestigial umbilical arteries), and Richet’s umbilical fascia (a subumbilical extension of transversalis fascia). Incomplete development, imperfect attachment, or weak areas in either ligamentous or fascial structures may predispose to herniation at the umbilicus. The defect is usually noticed within a few days or weeks after separation of the cord.3 As noted above, the process of umbilical ring closure can continue after birth for months or even years. INCIDENCE The true incidence of umbilical hernia is unknown because most umbilical hernias resolve spontaneously. Race and prematurity are predisposing factors with umbilical hernias found more commonly in children of African descent. The incidence of umbilical hernias decreases with advancing age. There is a high familial incidence, but no genetic pattern of inheritance has been identified. Umbilical hernia is commonly associated with a number of congenital malformations including thyroid dysgenesis, trisomy 18, trisomy 13, Operative Techniques in General Surgery, Vol 6, No 4 (December), 2004: pp 244-252 245 Umbilical Hernia Repair trisomy 21, Beckwith-Wiedemann syndrome, and Hurler syndrome.1 SURGICAL INDICATIONS An umbilical hernia may cause considerable parental anxiety and often results in requests for operative repair in early infancy. Because most umbilical hernias will decrease in size and close spontaneously, parents can be reassured and operation avoided in most children.4 Parents should be reminded not to apply straps, trusses, or coins to promote closure. Parents may associate abdominal pain and colic with the presence of an umbilical hernia, however, an umbilical hernia rarely causes pain. Incarceration and strangulation are absolute indications for surgical repair. If incarceration occurs, it can usually be reduced manually and the hernia repaired electively.1 Sedation may aid reduction of the hernia. Rupture and evisceration, although extremely rare, require immediate operation. Persistence of the hernia is the most common reason for operation. If the hernia persists as the child approaches school age (4-5 years of age), repair is recommended. Earlier repair (at age 2-3 years) is warranted if there is no reduction in the size of the hernia defect with serial observations. Fascial defects greater than 2.0 cm and “giant proboscoid hernias” should also be considered for earlier repair. PERIOPERATIVE CARE No preoperative testing is required in healthy children. Before the procedure, the child is kept without oral intake according to age and local pediatric anesthetic practices. Operative repair is performed as an outpatient procedure under general anesthesia. Local anesthetic infiltration, paraumbilical block, or a caudal epidural block can be used to minimize postoperative pain.2 Local/regional anesthetic administration before the incision may be more beneficial than at the time of closure. Oral analgesics are given in the early postoperative period before the local anesthesia wears off. Acetaminophen with codeine may be used for pain control for 24 to 48 hours. Postoperatively oral fluids can be offered when the patient is fully awake and alert. 246 Cilley and Shereef SURGICAL TECHNIQUE 1 The incision. After appropriate skin preparation and application of sterile drapes, a curvilinear incision is marked in a natural skin crease within or immediately below the umbilicus. The incision can often be hidden along or within the lower umbilical fold and need not be placed conspicuously on the abdominal wall skin. Grasping the redundant umbilical skin and applying traction to the abdominal wall facilitates the incision. The curved incision should not extend beyond 180°. Umbilical Hernia Repair 2 247 Dissection of the hernia sac. The subcutaneous tissue is incised and bleeding points controlled with fine tip electrocautery. A dissection plane is present between the subcutaneous fat and the hernia sac that leads to the fascial ring at the level of the abdominal wall. Any contents in the sac are reduced into the peritoneal cavity. With upward traction on the inner margin of the upper edge of the incision, dissection is performed in this plane along the sac to the level of the anterior abdominal wall fascia. The sac is dissected circumferentially by blunt dissection with a fine clamp. The plane of dissection is developed superiorly on either side of the sac until the sac is encircled. The sac is either transected or detached from the under-surface of the umbilical skin. It is important to avoid fenestration of the skin at the base of the umbilicus. The dissection of the hernia sac is extended into the plane between the abdominal wall fascia and the subcutaneous tissue of the abdominal wall for a variable distance. The dissection is limited to the minimum distance that allows closure of the fascia without distortion of the periumbilical skin. 248 3 Cilley and Shereef Repair of the defect. (A) The hernia sac is elevated, opened (if not already done) and inspected. Occasionally other umbilical abnormalities will be encountered such as urachal remnants or omphalomesenteric remnants and should be excised/repaired. Umbilical Hernia Repair 3 (B) The rim of the defect is identified and the sac incised to allow placement of sutures starting at one corner. 249 250 3 Cilley and Shereef (C) The remainder of the sac is excised and fascial sutures placed sequentially until the entire defect is controlled. Sutures are not initially tied to maintain control of the edge of the defect and avoid visceral injury. All of the sutures are then tied. Suture material may be either absorbable or nonabsorbable and is chosen according to the size of the patient (3-0 for infants and young children, 2-0 for older children and teenagers). 251 Umbilical Hernia Repair 4 Simple umbilicoplasty. The umbilicus is maintained in inversion by placement of sutures between the dermis and the fascial closure. The undersurface of the redundant umbilical skin is tacked to the anterior abdominal wall fascia with one or two interrupted 4-0 absorbable sutures. 5 Closure. A running fine absorbable suture is used to close the dermis. Skin sutures that require removal are avoided. Many pediatric surgeons use flexible collodion to dress the skin.5 A pressure dressing is applied and left in place for several days to prevent a wound hematoma. 252 Cilley and Shereef DISCUSSION Complications are uncommon, but wound hematoma and wound infection (1%) occasionally occur.4 Recurrence is rare. Wound infection makes recurrence more likely. The umbilicus may not have a perfectly natural appearance after operation and some patients are dissatisfied with the appearance. Supra-umbilical, epigastric hernias may occur alone or in conjunction with an umbilical hernia and should be repaired concurrently. A supra-umbilical incision allows both defects to be repaired. It is interesting to note that there is a wide range of technical variation in an operation that is performed so commonly. Some of the common technical alternatives are discussed below. 1. Closure of the fascia: The fascial closure can be performed using a closed technique. The sac is sharply detached from the umbilicus and inverted. The fascia edges are approximated without entry into the peritoneum and the sac is never opened. The dermis underlying the center of the umbilicus is secured to the fascia to restore the normal umbilical contour. 2. The distal sac can be left on the undersurface of umbilical skin. 3. A two-layer closure of the fascia may be performed either by imbricating the initial suture line or by overlapping the edges of the fascia. 4. Fascia may be closed in either a horizontal or a transverse fashion. Either absorbable or nonabsorbable suture material may be used. 5. The operation can be performed through the base of the umbilicus rather than through the traditional curvilinear incision below the umbilicus. A supraumbilical incision is also acceptable. 6. Excess or redundant skin can simply be ignored and the base of the umbilicus tacked to the fascia. The natural history of such repairs is unknown. Redundant skin can also be excised and a formal umbilicoplasty performed using a variety of techniques. These techniques are particularly useful in the case of a large proboscoid hernia. The true outcomes of umbilical hernia repair have not been studied in a long-term, prospective manner. It is not known whether any of the technical variations listed above result in fewer complications or improved longterm appearance. REFERENCES 1. Cilley RE, Krummel TM: Disorders of the Umbilicus, in O’Neill JA, Rowe MI, Grosfeld JL, et al (eds): Pediatric Surgery (ed 5, vol 2). Baltimore, MD, Mosby, 1998, pp 1029-1043 2. Garcia VF: Umbilical, other abdominal wall hernias, in Ashcraft KW, Murphy JP, Sharp RJ, et al (eds): Pediatric Surgery (ed 3). Philadelphia, PA, W.B. Saunders Company, 2000, pp 651-653 3. Shaw A: Disorders of the umbilicus, in Welch KJ, Randolph JG, Ravitch MM, et al (eds): Pediatric Surgery (ed 4, vol 2). Chicago, IL, Year Book Medical Publishers, Inc, 1986, pp 731-739 4. Grosfeld JL: Hernias in children, in Spitz L, Coran AG (eds): Rob & Smith’s Operative Surgery. Pediatric Surgery (ed 5). New York, NY, Chapman & Hall Medical, Lippincott Williams & Wilkins, 1995, pp 232-236 5. Singh G: Technical Bulletin, Collodion: http://surgery.psu.edu