Anatomy for the Gynecologic Oncologist

Anatomy for the Gynecologic
Oncologist
Chris DeSimone, M.D.
Assistant Professor
Division of Gynecologic Oncology
Overview
• Abdominal wall anatomy
• Upper abdomen organs, vessels,
innervation
• Pelvic anatomy
• Vulvar anatomy
Abdominal wall anatomy
• Best to comprehend the anatomy as it relates to
incision types – Midline, Pfannenstiel, Maylard &
Cherney
• What dermatomes are affected by a midline
incision? What are affected by a pfannenstiel?
• Name all the layers of the abdominal wall above
and below the arcuate line?
• Describe the relationship between the incision
type and the inferior epigastric artery?
Innervation of the abdominal wall
Musculature
Rectus sheath
Rectus sheath
Course of the epigastric artery
Veins of the abdominal wall
Upper abdominal anatomy
• Adequate debulking of ovarian carcinoma
requires dissection of several key organs
• What vessels supply the omentum,
spleen, stomach, small bowel, colon and
liver?
• What are their functions?
• How do you manage these organs
postoperatively if they are injured or
removed?
Omentum
• Functions as a filter for lymphatic fluid
• Lymph fluid flow in a clock-wise pattern
secondary to peristalsis of the ascending,
transverse and descending colon
• Brings lymph fluid to the cisterna chyli, the
thoracic duct and then the left brachiocephalic
vein
• Right sided lymphatic drainage is directed
through lymphatic channels of the diaphragm to
the azygos system and then the IVC and SVC
Omentum
Stomach
• Second organ involved with digestion
• Innervated by the vagus nerve
• Blood supply from the celiac trunk: left and right
gastric arteries, right and left gastroepiploic
arteries and the short gastric arteries
• Produces hydrochloric acid and pepsin to digest
food
• Produces 1 to 1.5 liters of fluid each day
• Injury can be controlled by primary closure
• Continuous NG suctioning causes a
hyponatremic, hypokalemic metabolic alkalosis
Stomach
Spleen
• Filter for senescent erythrocytes and circulating
pathogens
• Major producer of opsonins (properdin/ tuftsin)
• Hilum contains the splenic artery and vein
• Extremely vascular
• Splenocolic ligament must be mobilized to free the
splenic flexure of the colon
• Posterior aspect of this ligament in close proximity to the
tail of the pancreas
• Splenectomies patients are at risk for pneumonia,
bacteremia, pancreatic injuries and splenic abcesses
• MUST BE VACCINATED POST OPERATIVELY FOR:
– Streptococcus pneumoniae
– Haemophilus influenzae
– Nisseria meningitidis
Spleen
Small Bowel
• On average 270 to 290 cm in length
• Consists of the duodenum ( 20cm), jejunum (100 to
110cm) and ileum (150 to 160 cm)
• Entire blood supply from the superior mesenteric artery
• Both parasympathetic and sympathetic innervation
• Parasympathetic innervation is from the vagus nerve
which stems from the celiac ganglion
• Parasympathetic innervation controls motility and
secretion of enzymes
• Sympathetic innervation from three sets of splanchnic
nerves oriented around the base of the SMA
• Sympathetic innervation responsible for pain sensation
and blood vessel motility
Small Bowel
• Majority of nutritional uptake is responsible within the
jejunum and ileum
• 80% to 90% of proteins reabsorbed in the jejunum
• 95% of lipid reabsorbed within the jejunum and ileum
• 8 to 10 liters of water are reabsorbed, perhaps only 500
ml actually enter the cecum
• Fat soluble vitamins are reabsorbed in the terminal ileum
(A, D, E and K)
• Vitamin B12 also reabsorbed in the terminal ileum
• KEY POINT: the more small bowel removed expect
problems with digestion, nutrition and diarrhea
Small Bowel
• Enzymes of the small bowel
– Gastrin (D) promotes gastric acid and pepsinogen
production
– CCK (D) promotes pancreatic enzyme secretion and
gall bladder contraction
– Secretin (D,J) causes water release, secretion of bile
salts and inhibition of gastrin
– Somatostatin (P) universal off switch
– Gastrin releasing peptide (D,J,I) universal on switch
– Motilin (D,J) stimulates upper GI motility
Small Bowel
• Small Bowel Obstruction
– Adhesions 60%
– Malignancy 20%
– Hernias 10%
– Crohn’s disease 5%
– Miscellaneous 5%
Duodenum
Small Bowel
Small Bowel
Colon
• 6 segments – cecum and appendix,
ascending, transverse, descending,
sigmoid and rectum
• On average 130 to 150 cm in length
• Blood supply from the superior mesenteric
and inferior mesenteric arteries (SMA &
IMA)
Segments of the colon
Blood supply to the colon
Colonic function
• Absorption
– 1000 to 1500ml of ileal effluent crosses the ileocecal
valve
– Stool has 100 to 150 ml of water
– Descending colon mainly responsible
• Recycling of nutrients
–
–
–
–
Nonstarch polysaccharides
Short chain fatty acids
Urea
Ascending colon responsible
Colonic innervation
• Parasympathetic innervation from the vagus
nerve and the pelvic autonomic center S2-S4
• Nerves are centered in plexuses along the
subserosal and muscular components of the
colon: Auerbach and Meissner plexuses
• Controls colonic motility
• Sympathetic innervation is from the superior and
inferior mesenteric ganglia (found by the SMA
and IMA)
• Controls pain and vascular tonicity
Cecal anatomy
Appendix
• No appreciable utility
• Associated with carcinoid and primary
appendiceal carcinomas
• Must be taken for mucinous ovarian tumors
• Appendiceal artery arises from the ileocolic
artery and MUST be ligated
• Primary appendiceal tumors often diagnosed by
gynecologic oncologists as a right ovarian tumor
Appendix
Portal circulation
• Not essential for gynecologic malignancies;
however must understand the different source of
venous drainage
• Splenic vein, SMV, IMV, gastric veins involved in
the portal system
• Portal hypertension can therefore cause,
gastroesophageal varices, rectal varices and
medusae caput
• Acute bleeding has 25-30% mortality rate
• Patients with cirrhosis have a 50% mortality rate
Portal circulation
Pelvic Anatomy
• The home of the gynecologic oncologist
• Focus on blood supply, nerves of the
pelvis, musculature and rectal anatomy
• Must understand the boundaries of pelvic
lymph node dissection
– Lateral: genitofemoral nerve
– Medial: ureter
– Inferior: deep iliac circumflex vein
– Superior: inferior mesenteric artery
Pelvic blood supply
•
Aorta
– Middle sacral artery
•
•
Common iliac artery
External iliac artery
– Inferior epigastric artery
– Deep circumflex iliac artery
•
Posterior division of internal iliac artery
– Superior gluteal artery
– Iliolumbar artery
– Lateral sacral
•
Anterior division of internal iliac artery
–
–
–
–
–
–
–
Obturator artery
Uterine artery
Superior vesical artery
Inferior vesical artery
Umbilical ligament
Middle rectal artery
Internal pudendal artery
• Inferior rectal artery
• Labial arteries
• Dorsal artery of the clitoris
Pelvic blood supply
Pelvic blood supply
Common iliac artery
External iliac artery & vein
Superior vesical artery
Obturator space
Obturator nerve
Obturator artery
Obturator venous plexus
Pelvic nerves
•
Femoral nerve
– Nerve roots L2, L3, L4
– Provides motor function to the extensor muscles
– Provides sensation to the thigh
•
Sciatic nerve
–
–
–
–
•
Nerve roots L4, L5, S1, S2, S3
Largest nerve in the body
It divides into the tibial and peroneal nerves
Provides motor function to the distal extremity
Obturator nerve
– Nerve roots L2, L3, L4
– Provides motor function to the adductor muscles
•
Pudendal nerve
– Nerve roots S2, S3, S4
– Provides motor functions to the muscles of the pelvis and extern al anal
sphincter
– Provides sensation to the vulva and clitoris
•
Genitofemoral nerve
– Nerve roots L1, L2
– Provides sensation to the thigh and vulva
Pelvic nerves
Pelvic nerves
Muscles of the pelvis
• Psoas
– L2, L3, L4
flexes thigh
• Piriformis
– S1, S2
rotates thigh laterally
• Obturator internus
– L5, S1, S2
rotates thigh laterally
• Levator Ani
– Pubococcygeus
– Iliococcygeus
– Puborectalis
S3, S4 raise pelvic floor
• Coccygeus
– S4, S5
raise pelvic floor
Muscles of the pelvis
Muscles of the pelvis
Bladder
• Muscular structure which functions as a reservoir for
urine
• Can hold 1000 ml however most females have a strong
urge to void at 400 ml
• Supplied by the superior vesical and inferior vesical
arteries
• Innervation is both parasympathetic and sympathetic
• Parasympathetic (S2, S3, S4) controls detrusor
contraction while inhibiting the internal sphincter
• Sympathetic (T11, T12, L1, L2) transmit sensation
Bladder innervation
Rectum
• Last portion of the colon, rich blood supply, relatively
mobile below the peritoneum
• Multiple layers which control continence
– 1st it follows the contour of the sacrum
– 2nd the valves of houston produce sharp turns for the feces to
navigate
– 3rd the puborectalis muscles forms a sling around the rectum
called the anorectal angle
– All these layers close off the lumen with valsalva
• The pectinate line marks the transformation from
squamous epithelium to columnar epithelium
• Blood supply stems from both the IMA and the internal
iliac arteries (superior, middle, inferior rectal arteries)
Rectum
Rectum
Vulvar anatomy
• Layers of support to the pelvic floor
• Blood supply to the vulva
– Internal pudendal artery
• Inferior rectal artery
• Labial/ perineal arteries
• Dorsal artery of the clitoris
– External pudendal artery
• Nervous supply to the vulva
– Ilioinguinal nerve
– Pudendal nerve
• Labial/ perineal nerves
• Dorsal nerve of the clitoris
– Posterior femoral cutaneous nerve
• Points of interest with a inguinal lymphadenectomy
Vulva: deep to superficial
Vulva: deep to superficial
Vulva: deep to superficial
Vulva: deep to superficial
Vulva: deep to superficial
Vulvar blood supply
Vulvar blood supply
Vulvar blood supply
Lymphatic drainage of the vulva
Innervation of the vulva
Femoral Triangle
• Borders: Inguinal ligament superiorly, sartorius
muscle laterally and adductor longus medially
• Superficial inguinal lymph nodes above the
cribriform fascia (6-8)
• Femoral nerve, artery, and vein are found below
the cribriform fascia
• Deep inguinal lymph nodes (2-3)
• Cloquet’s node deepest most superior lymph
node before crossing inguinal ligament and
thereby external iliac lymph nodes
Femoral Triangle
Muscles of the thigh
• Sartorius
– L2, L3 (F)
Flexes, abducts and
laterally rotates thigh
• Gracilus
– L2, L3 (O)
Flexes, adducts and
medially rotates thigh
• Adductor longus
– L2, L3 (O)
Adducts thigh
Femoral and Obturator Nerves