Voiding Function After Midurethral Slings With and Without Local Anesthetic: Randomized Controlled Trial

This study aimed to compare the effect of periurethral infiltration of bupivacaine versus normal saline on postoperative voiding function and pain in patients undergoing retropubic midurethral sling METHODS: A randomized double-blind placebo-controlled study was performed at the University of Massachusetts from March 2012 to June 2015. Ninety patients were randomized to receive 0.5% bupivacaine with epinephrine or normal saline with epinephrine solution for periurethral hydrodissection. Postoperative pain was assessed at 2 to 3 and 6 to 7 hours using a visual analog scale. Voiding function was determined by the proportion of subjects passing or failing a voiding trial. Descriptive statistics and percentages were used to compare the rate of voiding dysfunction. A logistic regression analysis was performed adjusting for possible covariates.

Ninety subjects enrolled and 45 were randomized to each group. Thirty-nine subjects received the normal saline and 41 received bupivacaine. The remaining 10 withdrew before the procedure. Pain scores at 2 to 3 hours did not differ between the groups (P = 0.837), but at 6 to 7 hours, patients who received bupivacaine had less pain (P = 0.028). There was no difference in voiding dysfunction between the study and placebo groups (17.9% and 24.4%, respectively; P = 0.481). Because of the unavailability of indigo carmine midway through the study, 36 of 80 subjects received preoperative phenazopyridine for the assessment of ureteral patency. Three (8%) of these subjects failed their voiding trial compared with 19 (30%) of the patients who did not receive phenazopyridine (P = 0.010).

The use of bupivacaine did not affect postoperative voiding function but had lower pain scores at 6 to 7 hours postoperatively. Preoperative phenazopyridine may reduce postoperative urinary retention.