Does a Uterine Manipulator Increase the Distance of the Ureter to the Cervix and/or Vagina? An Anatomical Cadaver Study

Study Objective: To determine whether advancing a manipulator increased the distance of the ureter to the cervix and/or vagina. Design: Prospective. Setting: Academic institution. Patients: A total of 22 intact fresh-frozen female pelvises. Interventions: A total of 6 ureteral distances were measured per pelvis. Included were the following measurements on each side: (1) from the lateral cervical wall to the ureter at the intersection with the uterine artery; (2) from the lateral cervical wall to the parametrial ureter; and (3) from the vagina to the ureter at the intersection with the uterine artery. All measurements were obtained with and without advancement of a uterine manipulator. Measurements and Main Results: The average distance from the ureter to the cervix and vagina without advancing the manipulator was 2.8 and 3.1 cm, respectively, and the distance from the parametrial ureter to the cervix was 3.3 cm. When the manipulator was advanced, all ureteral distances increased by 0.8, 0.6, and 0.6 cm, respectively, in 12 of the 22 pelvises (55%). Advancing the manipulator did not increase at least 1 of the distances in 10 of the 22 pelvises (45%). The advancement of the manipulator lengthened the 2 shortest ureteral distances of 1 cm noted in 1 pelvis (4.5%) by 0.9 and 0.4 cm. Conclusion: The uterine manipulator increased the distance of the ureter to the cervix and vagina for all measurements in 55.5% of the pelvises. The greatest increase was 0.9 cm. The manipulator did not increase at least 1 of the distances in 10 of the 22 pelvises (45.4%).