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

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.