Preoperative Pelvic Floor Injections With Bupivacaine and Dexamethasone for Pain Control After Vaginal Prolapse Repair A Randomized Controlled Trial

OBJECTIVE: To test the hypothesis that preoperative pelvic floor muscle injections and pudendal nerve blocks with bupivacaine and dexamethasone would decrease postoperative pain after vaginal native tissue prolapse repairs, compared with saline and bupivacaine. METHODS: We conducted a three-arm, double-blind, randomized trial of bilateral transobturator levator ani muscle injections and transvaginal pudendal nerve blocks before vaginal reconstructive and obliterative prolapse procedures (uterosacral ligament suspension, sacrospinous ligament fixation, levator myorrhaphy, or colpocleisis). Women were randomized to one of three study medication groups: 0.9% saline, 0.25% bupivacaine, or combination 0.25% bupivacaine with 4 mg dexamethasone. Our primary outcome was a numeric rating scale pain score on postoperative day 1. Using an analysis of variance evaluated at the two-sided 0.05 significance level, an assumed variance of the means of 0.67, and SD of 1.75, we calculated 21 women per arm to detect a 2-point change on the numeric rating scale (90% power), which we increased to 25 per arm to account for 20% attrition and the use of nonparametric statistical methods. RESULTS: From June 2017 through April 2019, 281 women were screened and 75 (26.7%) were randomized with no differences in baseline demographics among study arms. There was no significant difference in median pain scores on postoperative day 1 among study groups (median [interquartile range] pain score 4.0 [2.0-7.0] for placebo vs 4.0 [2.0-5.5] for bupivacaine vs 4.0 [1.5-5.0] for bupivacaine with dexamethasone, P=.92). CONCLUSION: Preoperative pelvic floor muscle injections and pudendal nerve blocks with bupivacaine and dexamethasone did not improve postoperative pain after vaginal native tissue prolapse procedures.