A 47-year-old woman with a family history of breast cancer mutations in the BRCA1 and BRCA2 genes has made a decision to have an elective hysterectomy as a prophylactic treatment. During ligation of the uterine artery which of the following adjacent structures must the surgeon be careful not to injure?

During a hysterectomy, ligation of or injury to the ureter can happen relatively easily because it is the most susceptible structure due to its location. The ureter is located below the uterine vessels in the pelvic cavity approximately 1 cm lateral to the supravaginal cervix. The internal iliac artery bifurcates near the pelvic brim but is not in close proximity to the uterine vessels in the vicinity of the cervix. The obturator nerve travels along the pelvic sidewall and is not close to the site of ligation of the uterine vessels. The lumbosacral trunk is located on the lateral side of the sacrum and the pelvic sidewall, not in close proximity to the uterine vessels.