372 Obstetrics and Gynecology Board Review •••
❍ What injury to the urinary tract is the most difficult to recognize?
Injury to ureter.
❍ What injury to the urinary tract produces the most serious complications?
Injury to ureter.
❍ Where is the most common site of ureteral injury?
Approximately 80% to 90% of all ureteral injuries occur in the distal portion of the ureter from the uterine artery
to the ureterovesical junction.
❍ At what sites is the ureter at greatest risk?
Understanding of pelvic anatomy is essential to avoid injuries to the ureter. There are several danger zones
encountered as the ureter travels through the pelvis.
- Bifurcation of the iliac vessels as the ureter enters the pelvis and runs medial to the branches of the anterior
division of the internal iliac artery. Injury can occur during oophorectomy, lymphadenectomy, or hypogastric
artery ligation. - At the level of the cardinal ligaments as the ureter passes under the uterine artery.
- Vaginal fornices as the ureter passes medial to them in order to enter the bladder trigone.
- Uterosacral ligaments during culdoplasty, endometriosis ablation, or while performing high uterosacral ligament
suspension vaginally.
❍ What types of ureteral injury can occur?
(1) Crushing injury from misapplication of surgical clamps, (2) ligation with suture, partial, or complete transection,
(3) angulation with partial or complete obstruction, (4) ischemia from stripping of the adventitia and decreased
blood supply to that part of the ureter, and (5) resection of a segment of ureter intentionally or unintentionally.
❍ What pelvic conditions may predispose to ureteric injury?
Lateral displacement of the cervix by tumors or large fibroids, masses adhering to the peritoneum overlying the
ureter, intraligamentary tumors, retroperitoneal tumors, abscesses in the broad ligament, and cervical cancer.
❍ What technique should be used to mobilize masses that may involve the ureter?
Open the retroperitoneal space lateral to the mass, identify the ureter, and dissect the mass away from the ureter
under direct visualization.
❍ Where does ureteral injury most often occur during abdominal surgery?
Where the ureter crosses beneath the uterine artery lateral to the cervix. This happens most often when trying to
gain hemostasis.
❍ True or False: Using ureteral stents prevents intraoperative injury to the ureters.
False.
❍ What techniques protect against ureteral injury at the time of vaginal hysterectomy?
Ureteral injury occurs rarely in vaginal hysterectomy, despite the fact that downward traction on the uterus pulls
the ureter downward. Clamping the uterine vessels at a right angle to the vessel and as close to the uterus as
possible will decrease the risk of ureteric injury.