Precise localization of the ureters is recommended before all operative interventions. Ureteral dissection and displacement from harm is recommended whenever the possibility of ureteral injury exists. Placement of ureteral catheters preoperatively is recommended in patients with extensive pelvic disease that distorts the pelvic anatomy.
INDICATION FOR URETERAL DISSECTION
1. When operating near the ureter, it is safer and faster to dissect and expose the ureter to clear view than to stop repeatedly and check its position or perform the dissection under emergency circumstances.
2. Ureteral dissection is recommended in the following instances:
a. Obliteration of rectovaginal pouch by deep fibrotic endometriosis b. Medial displacement of ureter near uterosacral ligaments
c. Excision of deep fibrotic endometriosis from vaginal cuff and uterosacral ligaments, status posthysterectomy
d. Deep endometriosis adherent to or partially obstructing the ureter
e. Left-frozen-pelvis from endometriosis
f. Ovary, oviduct, or sigmoid colon adherent to ureter
g. Extensive chronic salpingo-oophoritis
h. Laparoscopically assisted vaginal hysterectomy (LAVH) for endometriosis
i. Extraperitoneal lymphadenectomy for malignancy
j. To isolate and ligate retracted bleeding uterine artery
1. Anatomic divisions of the ureter
a. The iliopectineal line divides the ureter into abdominal and pelvic portions. The pelvic ureter is divided into the following three parts:
(1) The pars posterior, which runs from the sacroiliac joint along the lateral pelvic wall to the entrance of the preformed tunnel in the cardinal ligament
(2) The pars intermedia, which runs within the broad ligament to the vesicouterine ligament
(3) The pars anterior, which runs from the entrance into the vesicouterine ligament to the ureteral orifice of the bladder
b. The left ureter may be identified above the iliopectineal line at the apex of the intersigmoid fossa by displacing the left adnexa anterolaterally and the sigmoid colon medially and cephalad. In difficult cases, the ureter may be located near the pelvic brim, lateral to the pulsations of the hypogastric artery. Normal peristalsis should be observed. When the ureter lies close to the infundibulopelvic ligament, the infundibulopelvic ligament must be displaced laterally. This maneuver compresses the peritoneum over the ureter and facilitates identification, c. The right ureter crosses the iliac vessels at the bifurcation of the common iliac artery and is easier to locate than the left ureter. Near the pelvic brim, it lies lateral to the pulsations of the hypogastric artery.
2. Congenital anomalies: medial displacement of one or both ureters occurs in the following ways.
a. As an isolated congenital anomaly
b. In association with peritoneal pockets in the posterior pelvis
c. As the medial border of a large broad ligament recess
3. The sigmoid colon traps menstrual detritis against the left ureter, increasing the risk of endometriosis. It may also envelop the left tube and ovary in dense obliterative adhesions in response to repeated ruptures of an ovarian endometrioma.