Uterosacral ligament: description of anatomic relationships to optimize surgical safety

Abstract

Objective: To determine the optimal site in the uterosacral ligament for suspension of the vaginal vault with regard to adjacent anatomy and suspension strength. Methods: Fifteen female cadavers were evaluated between December 1998 and September 1999. Eleven hemisected pelves were dissected to better define the uterosacral ligament and identify adjacent anatomy. Ureteral pressure profiles with and without relaxing incisions were done on four fresh specimens. Suture pullout strengths also were assessed in the uterosacral ligament. Results: The uterosacral ligament was attached broadly to the first, second, and third sacral vertebrae, and variably to the fourth sacral vertebrae. The intermediate portion of the uterosacral ligament had fewer vital, subjacent structures. The mean ± standard deviation distance from ureter to uterosacral ligament was 0.9 ± 0.4, 2.3 ± 0.9, and 4.1 ± 0.6 cm in the cervical, intermediate, and sacral portions of the uterosacral ligament, respectively. The distance from the ischial spine to the ureter was 4.9 ± 2.0 cm. The ischial spine was consistently beneath the intermediate portion but variable in location beneath the breadth of the ligament. Uterosacral ligament tension was transmitted to the ureter, most notably near the cervix. The cervical and intermediate portions of the uterosacral ligament supported more than 17 kg of weight before failure. Conclusion: Our findings suggest that the optimal site for fixation is the intermediate portion of the uterosacral ligament, 1 cm posterior to its most anterior palpable margin, with the ligament on tension.