Surgical Core Curriculum - Gyn Onc

1. Surgical Core Curriculum- Gyn Onc Amreen Husain, M.D.

2. Abdominal Wall • Determine best incision for planned surgery • Several layers depending on the orientation of incision • Course of vessels in abdominal wall. • Potential need for preservation of epigastric vessels • Potential placement of stoma

3. Abdomen • Landmarks to note • Costal margins • Xiphoid process • Umbilicus • Anterior superior iliac spines • Inguinal creases • Pubis

4. Layers of abdominal wall • Skin • Superficial fascia • External and internal obliques • Transversus abdominis muscles, Aponeurosis and fascia • Rectus muscles and sheaths • Preperitoneal fat • Parietal peritoneum

5. Rectus muscle • Blood supply derived from sup epigastric artery (branch of int mammary or thoracic artery) and inf epigastric artery (branch of external iliac artery. • Nerve supply from anterior rami of thoracic nerves from T6-T12 which enter posteriorly then divide ant, medial and lateral. Denervation occurs if muslce is divided longitudinally or freed laterally

11. The Pelvis • Surrounded by bony structures: • Sacrum, ischium, ilium and pubic bones • Floor is composed of muscles: • Piriformis, coccygeus and levator ani

12. The Pelvis • Divided into an anterior and posterior component by the transversely oriented broad ligament in the center of which is the uterus • Broad ligament has two layers : anterior and posterior leaves, round ligament runs anterolateral in the broad ligament to the pelvic wall

13. The Pelvis • Ovaries attached to posterior leaf of the broad ligament by meso-ovarium, to the uterus by the ovarian ligament and to the pelvic wall by the infidibulo-pelvic ligament which contains the ovarian vessels and lymphatics • Adnexal triangle an important landmark – bounded ant by round ligament, post by IP ligament and laterally by peritoneal reflection over psoas. Allows easy access to the retroperitoneum

15. Surgical Anatomy of the Pelvis • Pelvic organs include the uterus, cervix and vagina, ovaries and Fallopian tubes, bladder, pelvic ureters, rectum and portion of the sigmoid • Eight tissue planes which are avascular two dimensional potential spaces until developed by the surgeon • Three pairs of fibrovascular ligaments

16. Avascular Tissue Planes • Paired Spaces: • Paravesical/paravaginal spaces • Pararectal spaces • Unpaired spaces: • Prevesical (retropubic) space of Retzius • Vesicovginal space • Rectovaginal space • Presacral (retrorectal) space

18. Fibrovascular ligaments • Cardinal ligaments • Constitute the thickened posterior most portion of broad ligament • Arises from endopelvic fascia of the lateral cervix and extends to pelvic sidewall where it inserts into the endopelvic fascia • Posterior portion contains a major component of the autonomic nerve supply to the bladder and rectum • Contains the uterine, vaginal, inferior vesical and middle rectal arteries and veins as well as lymphatics • Ureter penetrates upper portion just below uterine artery 1-2 cm lateral to the isthmus of the uterus

19. Fibrovascular ligaments • Uterosacral ligaments with rectal pillars • Posterolateral thickenings which originate from posterolateral aspect of the cervix and run to anterolateral aspect of the rectum • they straddle the posterior cul-de-sac • Rectal pillars are longitudinal fibrovasuclar bundle btwn vagina and rectum, run the length of the vagina

20. Fibrovascular ligaments • Bladder pillars • Paired longitudinal fibrovascular bundles that run the length of the vagina anteriorly and form the lateral limits of the vesicovaginal space • Upper end connects to the lower half of the cervix forming the vesico-uterine ligament

22. The Ureter • Crossing Retroperitoneal during its entire passage from the kidney to the bladder. • Enters the pelvis by crossing over the vessels at or just proximal to the bifurcation of the common iliac artery • On the left it passes under the proximal sigmoid colon and on the right passes under the cecum and terminal ileum

23. The Ureter • As the ureter enters the pelvis it becomes attached to the lateral pelvic wall peritoneum and continues till it reaches the level of the uterosacral ligament and the posterior leaf of the broad ligament • Ureter then contiunues through the cardinal ligament to the bladder going under the uterine artery

26. Arteries and Veins • Ovarian vessels • Ovarian arteries arise from the abdominal aorta 2-3 cm below the renal arteries • Ovarian vein on the right enters the vena cava below the right renal vein; the ovarian vein on the left enters the renal vein lateral to the vena cava

27. Arteries and Veins • Common iliac vessels • Common iliac artery begins at the lower end of L4 and follows the pelvic brim laterally terminating over the sacroiliac joint by dividing into the external iliac and hypogastric (internal) iliac arteries • Ureter crosses both common iliac arteries near their bifurcation • Common iliac veins lie posterior to the artery, the left common iliac vein passes under the proximal part of the right common iliac artery

28. Arteries and Veins • External iliac vessels • External iliac vein arises at lumbosacral joint and ends by passing under the inguinal ligament to become the femoral artery • Main branches are the deep circumflex and inferior epigastric vessels • External iliac veins are positioned inferiomedial to the arteries

29. Arteries and Veins • Hypogastric Arteries • Posterior and Anterior divisions at 4 cm from its origin • Anterior Trunk : Six primary branches in order • Common branch giving rise to the uterine, umbilical, superior vesical and sometimes vagina • Obturator, Inferior vesical, middle Rectal, internal pudendal and inferior gluteal • Posterior Trunk • Four branches none of which supply pelvic viscera • Iliolumbar, superior and inferior lateral sacral, superior gluteal

33. The Groin • Femoral Triangle • Bounded superiorly by the inguinal ligament, laterally by the medial border of the sartorius muscle and medially by the adductor longus muscle • Structures passing via the subinguinal space from the pelvis to the leg from lateral to medial are the lateral femoral cutaneous nerve, iliopsoas muscle, femoral nerve, then the femoral artery, femoral vein, femoral canal w/ lymphatics and femoral branch of the genitofemoral nerve

35. The Small Intestine • Jejunum and Ileum combined average 22 ft in length of which the jejunum accounts for 40%. • Jejunum and ileum differ in that the jejunum is thicker, has thicker mucosal folds, the mesenteric fat extends onto the wall of the ileum but not the jejunum, the vasa recta are shorter in the ileum

36. The Small Intestine • Arterial Supply • Entire blood supply derived from the superior mesenteric artery (SMA) a ventral midline branch of the aorta. • SMA enters the base of the mesentery as it emerges from between the duodenum and pancreas • Branches are : Common inferior pancreaticoduodenal a., the middle and right colic a., ileocolic a., series of jejunal and ileal branches which anastomose with each other forming arcades.

37. The Large Intestine • 4-6ft in length from ileocecal junction to the anus. • Divisible into the cecum and appendix; the ascending, transverse, descending and sigmoid colon; Rectum and anus • Ascending and descending colon are retroperitoneal while transverse and sigmoid colons have distinct mesenteries

39. The Large Intestine • Arterial Supply • Derived from superior and inferior mesenteric arteries • Marginal artery of Drummond is a scalloped continuous vessel formed by anastomosing arcades of the ileo-colic, right, middle, left colic and sigmoidal arteries • Inferior mesenteric artery (IMA) arises from the aorta at L# about 3-4 cm from bifurcation, • Branches to the left colic artery, sigmoidal arteries (2-4), becomes the superior rectal artery in the pelvis

41. Ureteral Injuries • Incidence is 0.1% - 1.5% in pelvic surgery • 75% during gynecologic surgery • ¾ during abd surgery • ¼ during laparoscopic surgery • Most common causes of litigations against gyn surgeons

42. Anatomy of the Ureter • Retroperitoneal • 25-30cm in length : divided into abdominal and pelvic segments by the pelvic brim • Three layers : • mucosa lined with transitional epithelium • muscularis made up of interweaving smooth muscle fibers • Adventitia containing intercommunicating network of blood vessels

43. Embryology • Close proximity to reproductive organs due to proximity of mesonephric ducts and mullerian system • Congenital anomalies occur concomitantly 35- 40% of the time • Most common is ureteral duplication – 1% of women

44. Blood supply • Segmental with much anastomising • Cephalad – supplied by branches of renal and ovarian arteries • Middle – form aortic and common iliac branches • Pelvic – from hypogastric, rectal and vaginal arteries

46. Path of the ureter • Abdominal ureter : runs along anterior surface of the psoas muscle and posterior to the ovarian vessels • Crosses pelvic brim anterior to common iliac at its bifurcation

47. Path of the Ureter • Pelvic ureter: travels along the pelvic sidewall lateral to the sacrum and anterior to the hypogastric. Veers medial as it passes beneath the uterine artery approx 1.5cm lateral to the internal os then passes into the tunnel of the cardinal ligament and travels medially and anteriorly over the vaginal fornix to enter the bladder. • Travels 2cm within bladder wall before exiting

48. Location of ureteral injuries • Cardinal ligaments where uterine artery and ureter cross or at the ureteral tunnel • Infundibulopelvic ligament • Lateral pelvic sidewall along the uterosacral ligaments • Intramural portion of ureter

49. Types of injuries • Crushing from a clamp • Ligation • Transection • Angulation with secondary obstruction • Ischemia due to thermal injury • Resection

50. Prevention • Identification and visualization • After dividing round ligament enter broad ligament along psoas muscle and dissect retroperitoneal space, ureter is attached to the medial leaf of the broad ligament • No benefit to preop IVP or stenting • Can also be palpated (with experience!!) • Can also be identified as it crosses iliac