This study aimed to compare a backfill-assisted voiding trial (VT) with and without a postvoid residual (PVR) after pelvic reconstructive surgery.
This was a nonblinded randomized controlled trial of women undergoing pelvic organ prolapse and/or stress incontinence surgery. Participants were randomized immediately after surgery to either a PVR VT or a PVR-free VT. Our primary outcome was the rate of VT failure at discharge. Secondary outcomes included days of catheterization, urinary tract infection (UTI), and prolonged voiding dysfunction. With a power of 80% and an α of 0.05, we needed 126 participants to detect a 25% difference in VT failure (60% in PVR VT vs 35% in PVR-free VT).
Participants were enrolled from March 2017 to October 2017. Of the 150 participants, mean age was 59 years, and 33% underwent vaginal hysterectomy, 48% underwent anterior repair, and 75% underwent midurethral sling. Seventy-five (50%) were randomized to PVR VT and 75 (50%) to PVR-free VT, with no differences in baseline demographic or intraoperative characteristics between the 2 groups. Our primary outcome, VT failure, was not significantly different (53% PVR VT vs 53% PVR-free VT, P = 1.0). There were no significant differences in days of postoperative catheterization (1 [0, 4] in PVR VT vs 1 [0, 4] in PVR-free VT, P = 0.90), UTI (20% PVR VT vs 20% PVR-free VT, P = 1.0), or postoperative voiding dysfunction (4% PVR VT vs 5% PVR-free VT, P = 1.0).
When performing a backfill-assisted VT, checking a PVR does not affect VT failure, postoperative duration of catheterization, UTI, or voiding dysfunction.