Effect of Pudendal Blockade on Bladder Emptying After Midurethral Sling: A Randomized Controlled Trial.

Objectives: To evaluate the effect of bilateral pudendal nerve blockade on immediate postoperative bladder emptying after midurethral sling.

Methods: We performed a double-blinded, randomized, placebo-controlled trial of women undergoing a midurethral sling procedure between October 2017 and February of 2019. Women older than 18 years were eligible if they were undergoing a midurethral sling with no concomitant procedures and had no preoperative urinary retention. Participant demographics and medical conditions that may affect bladder emptying were recorded preoperatively. Participants were randomized to a bilateral pudendal injection of either bupivacaine or normal saline. After induction of anesthesia, the pudendal injection was administered before any incisions. No other local anesthesia was used. The primary outcome was the rate of passing a standardized void trial. Secondary outcomes included perioperative pain scores, analgesia use, and complications.

Results: Ninety-one participants were enrolled in the study. One patient had a delayed void trial on postoperative day 1, leaving 90 participants for the final analysis. Demographic and perioperative characteristics were similar between the groups. Adjusted logistic regression showed that the administration of a bupivacaine pudendal block led to a higher rate of void trial failure (43% vs 20%, odds ratio = 0.32, P = 0.02 adjusted for age, body mass index, and comorbidities). Postoperative pain scores and analgesia use were similar between the groups. Postoperative complications, including urinary tract infection, mesh erosion, pelvic hematoma, or urinary retention within 6 weeks were similar between the groups.

Conclusions: Our prospective trial demonstrates that a bilateral pudendal blockade before midurethral sling procedure worsens postoperative bladder emptying.