Randomized Controlled Trial of Gabapentin Versus Placebo for Postoperative Pain After Sacrospinous Ligament Fixation for Pelvic Organ Prolapse

Pelvic organ prolapse (POP), the herniation of the bladder, uterus, or rectum, into and often beyond, the vaginal opening, affects 40% of postmenopausal women and significantly impairs quality of life. POP is often managed surgically, and currently, one in every eight women will undergo POP surgery during her lifetime.

A commonly performed procedure for POP is a sacrospinous ligament fixation (SSLF), which is a vaginal surgery that involves suspending the vaginal apex to the sacrospinous ligament suspension with sutures. Beyond routine postoperative pain, a sacrospinous ligament fixation may result in significant gluteal pain as a result of the vaginal sutures affecting/impinging on the sacral nerve roots. Unfortunately, postoperative gluteal pain is not uncommon with 12% of patients reporting significant gluteal pain and 4% having persistent pain 6 weeks after surgery.

This study aims to compare the impact of gabapentin versus placebo on postoperative pain after SSLF. The rationale is that studies have shown that preoperative gabapentin, a non-opioid analgesic, resulted in a lower narcotic use postoperatively. Decreasing the use of standard of care postoperative narcotic pain medications would also decrease adverse events due to narcotics such as nausea, vomiting, and constipation, and potentially decrease the long-term risk of opioid dependence. As an additional benefit, a careful assessment of actual opioid will help to inform best practices for prescribing, as we may be overprescribing narcotic medications for this type of surgery. This study will evaluate a longer two-week course of gabapentin because it is currently standard of care to use gabapentin to treat neuropathic pain after SSLF; thus, gabapentin may help to address overall pain as well as neuropathic gluteal pain that can occur after SSLF. Furthermore, gabapentin is a relatively safe medication with the primary adverse events being dizziness and sedation.

Given the risk of overall postoperative pain and neuropathic gluteal pain after a sacrospinous ligament fixation for POP and the evidence that perioperative gabapentin may decrease acute pain and neuropathic pain, this study proposes a novel randomized trial to compare perioperative gabapentin versus placebo on postoperative pain after a vaginal SSLF surgery.