A randomized controlled trial comparing two voiding trials after midurethral sling with or without colporrhaphy.

Introduction and Hypothesis: To compare the force of the stream (FOS) voiding trial with the standard voiding trial (SVT) after outpatient midurethral sling (MUS) whether or not colporrhaphy was performed.
Methods: This is a randomized controlled non-inferiority trial of patients scheduled for MUS or colporrhaphy. Sample size of 102 patients was calculated for 80% power. Patients were randomized to FOS or SVT. Primary outcome was the number of unexpected postoperative visits (UPOVs) for voiding dysfunction (VD) or urinary tract infection (UTI). Voiding dysfunction was defined as urinary retention or post-void residual (PVR) > 200 cc. Subjects rated FOS using a visual analog scale (VAS). Criterion for non-inferiority was an upper limit of < 10% for the 95% CI. Analyses were performed using SAS version 9.4 (SAS Institute. Cary, NC).
Results: One hundred two subjects were included (49 FOS, 53 SVT). Immediate postoperative catheterization for FOS and SVT was 8.2% (n = 4) and 9.4% (n = 5), respectively. Recovery time was significantly less for FOS versus SVT (p = 0.0002). Total UPOVs were five (10.2%) and two (3.8%) for FOS and SVT, respectively. Two FOS subjects who had MUS + colporrhaphy passed their VT and had subsequent UPOVs for VD. No evidence of non-inferiority was noted when comparing FOS to SVT for total UPOVs: CI: 6.0% (-5.2, 17.2) for postoperative VD [CI: 6.1% (-4.0, 16.2)] or UTIs [CI: 0.3% (-9.4, 10.1)].
Conclusions: No evidence of non-inferiority was noted comparing FOS with SVT for unexpected postoperative visits for voiding dysfunction or UTI. This study shows the need for larger studies to assess the use of the FOS method in patients undergoing surgery for prolapse with or without MUS.