The tensile strength of uterosacral ligament sutures: A comparison of vaginal and laparoscopic techniques

Abstract

Objective To compare the tensile strength of two approaches for uterosacral ligament suturing using a cadaver model. Methods In 12 unembalmed cadavers, four polytetrafluoroethylene sutures were placed through the uterosacral ligaments. In each cadaver, two sutures were placed laparoscopically, and two more were placed vaginally. A single, experienced surgeon placed all laparoscopic sutures ( n = 23), and another experienced surgeon placed all vaginal sutures ( n = 22). A blinded team of investigators measured the distance from each suture to the ipsilateral ischial spine; determined whether any sutures incorporated ureters, viscera, or large vessels; and then passed the sutures through an apical vaginal incision. Using a hand-held tensiometer, progressive tensile load was then applied to these sutures along the axis of the vagina until they either broke or were completely dislodged from the ligaments. Results The average peak tension required to break or dislodge the sutures was 26.2 ± 8.8 psi (laparoscopic) and 22.5 ± 7.4 psi (vaginal) ( P = .14, 95% confidence interval [CI] −1.2, 8.6). The average force required for suture breakage ( n = 28) was 28 ± 7 psi, and the average force applied when ligament failure occurred ( n = 17) was 18.5 ± 6 psi ( P < .001, 95% CI −13.8, −5.2). The average distance from a laparoscopic or vaginal suture to the ipsilateral ischial spine was 19.1 ± 7 mm and 17.4 ± 6 mm, respectively ( P = .46, 95% CI −3.0, 6.4). None of the sutures from either technique were found to incorporate a visceral structure, ureter, or great vessel. Conclusion These suturing techniques appear to be equal in tensile strength.