Transvaginal sacrospinous colpopexy: anatomic landmarks to be aware of to minimize complications.

Transvaginal sacrospinous colpopexy is currently used to repair varying degrees of vaginal vault prolapse. It involves placing a stitch from the vaginal cuff to the sacrospinous ligament approximately 2 cm medial to the ischial spine to correct the defect. This may be associated with pudendal artery and nerve (pudendal complex) along with sciatic nerve injury if the procedure is not carefully performed. This study was designed to emphasize the anatomic landmarks that make the sacrospinous ligament a potentially dangerous zone that surgeons must be aware of to minimize complications. Twenty-four female cadavers were obtained from the Louisiana State University Medical School anatomy laboratory. They were carefully dissected to expose the anatomic structures of interest. The following measurements were then obtained: the distance from the ischial spine to the medial border of the sacrum, the medial and lateral aspects of the pudendal complex, and the sciatic nerve. The obstetric conjugate of the pelves was also obtained. The pudendal complex and sciatic nerve were found to be 0.90 to 3.30 cm medial to the ischial spine. After the six smallest and largest pelves were compared, it was noted that the larger the obstetric conjugate the longer the sacrospinous ligament and vice versa. Also, the distance from the ischial spine to the sciatic nerve correlated with the size of the obstetric conjugate. The pudendal complex and sciatic nerve travel underneath the lateral third of the sacrospinous ligament. Therefore we recommend that the placement of the stitch be made medial to that portion of the ligament. More importantly, the stitch must be placed as superficial as possible and never across the entire thickness of the sacropinous ligament. This should decrease the rate of complications associated with this type of colpopexy.