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

Abstract

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.

Postoperative Urinary Retention

“…Local anesthetics often are used for hydrodissection, vasoconstriction, and pain management during MUS placement and have not been associated with an increased incidence of POUR 46–48 . Limited data exist on the effect of pudendal nerve block on POUR 49 …”

“…A single RCT in women undergoing a retropubic MUS and a bilateral pudendal nerve block found higher rates of VT failures in the women who received 0.25% bupivacaine versus saline. 49 87.50…”

“…[46][47][48] Limited data exist on the effect of pudendal nerve block on POUR. 49 While patients undergoing posterior colporrhaphy often have preexisting chronic constipation and have an increased risk of POUR as compared to patients undergoing other pelvic floor surgeries, there is limited evidence to suggest that constipation directly increases the risk of POUR after urogynecologic surgery. 112 Fecal impaction has been found to increase the risk of POUR in the orthopedic literature.…”