A randomized trial of retropubic versus single-incision sling amongst patients undergoing vaginal prolapse repair

Abstract

Choice of midurethral sling type may impact efficacy and complications in women undergoing transvaginal native tissue repair of pelvic organ prolapse (POP). The primary aim was to determine if single-incision (SI) sling is noninferior to retropubic (RP) sling for management of stress urinary incontinence (SUI) amongst patients undergoing reconstructive or obliterative native tissue vaginal repair. The secondary aims were to compare adverse events and surgeon ease of use with sling assignment. A multicenter, noninferiority, randomized trial of women with ≥ Stage II POP and objectively confirmed SUI undergoing reconstructive or obliterative vaginal repair was performed. Women were randomized to concomitant SI (Altis sling, Coloplast Minneapolis, MN) with suprapubic sham incisions or RP sling. The primary, dichotomous outcome was abnormal lower urinary tract function within 12 months post-surgery, defined as: bothersome SUI symptoms (>1 PFDI question #17); retreatment for SUI; or treatment for urinary retention. Secondary outcomes were adverse events, patient global impression of improvement of bladder function (PGI-I) and surgeon ease of use (1 worst, 10 best). All subjects completed validated questionnaires and underwent a POP-Q, cough stress test and post void residual (PVR) pre-operatively, at 6 weeks and 12 months post operatively. Assuming a subjective cure rate for RP of 82%, 80% power and one-sided 5% significance level, we estimated that 127 patients in each arm were needed to declare noninferiority of the SI sling if the upper bound of the 95% confidence interval for the between group difference per protocol in abnormal bladder function was less than 12%. Assuming a 10% loss to follow-up, the total enrollment goal was 280. Between 12/2018 and 1/2023, 280 subjects were enrolled across 7 sites and 255 were randomized: 126 to SI and 129 to RP sling. There were no pre-operative or operative characteristic differences between groups. Overall, 81% had reconstructive and 19% had obliterative native tissue repairs. The primary outcome, abnormal lower urinary tract function at 12 months, occurred in 29 (25%) of SI vs. 24 (20%) of RP sling group (Risk difference 0.04472, 95% CI (-0.03-0.1133), p = 0.001 for noninferiority). Bothersome SUI occurred in 20% vs. 17% (p=0.27) and was re-treated in 4% vs. 2% (p=0.44) of SI vs. RP groups, respectively. Adverse events were reported in 24 (16%) of SI vs. 14 (9%) of RP group (95% CI, 0.95-3.29; p=0.7) and included de novo or worsening urgency incontinence symptoms, urinary tract infection, mesh exposure, need for prolonged catheter drainage, and de novo pain, without differences between groups. PGI-I (very satisfied & satisfied) was 71% vs. 67% (p=0.43) and median surgeon ease of sling use was 8 [7-10] vs. 9 [8-10], p=0.03 in SI vs. RP, respectively. For women undergoing vaginal repair, SI was noninferior to RP sling for SUI symptoms and complications, including treatment for urinary retention, did not differ.