Effectiveness and Secondary Incontinence Rates after Urethroplasty for Severe Radiation-Induced Urethral Stenosis: A Systematic Review and Meta-Analysis

Abstract

Radiation-induced urethral stenosis (RIUS) is an important complication after cancer treatment, which sometimes requires surgical urethroplasty. To date, there is no precise estimate of effectiveness of urethroplasty and rates of secondary urinary incontinence (SUI) in this scenario. A systematic search of databases (PubMed and EMBASE) was performed with the terms “urethroplasty”, “radiotherapy”, “stenosis” and their variants. The pooled summary of overall stenosis resolution rate and the proportion of cases that developed SUI were calculated using the random-effects model weighted by the inverse variance. All statistical analyses were performed using R software version 3.5.1. This study is registered in the Open Science Framework online public database (10.17605/OSF.IO/WDQZJ). Using our search strategy, 96 studies were initially found. After applying inclusion and exclusion criteria, 8 retrospective studies met requirements for the meta-analysis, totaling 256 patients (98.4% prostate cancer and 1.6% colorectal cancer). Mean age of the patients from the series varied between 67.7-69 years. The proportion of cases treated with EBRT, BT, combination EBRT, or not specified were 45.7%, 28.9%, 13.3%, and 12.1%, respectively. Most of the strictures involved the bulbomembranous region (n = 212, 82.8%), followed by membranous only (9.8%), bladder neck (1.6%), pan-urethral (0.8%), or not specified (5.1%). Sixty-one percent of the cases (n = 157) were submitted to primary anastomosis, while the remaining (n = 86) required reconstruction with graft or flap. The mean follow-up time after urethroplasty varied in the range of 10 months and 50.5 months. The pooled stenosis resolution rate was 80% (95%CI: 74-86%). There was no correlation between percentage of reconstructive techniques (Spearman’s rank correlation coefficient [rho] = 0.20, p = 0.74) or percentage of combined EBRT + BT (rho = -0.31, p = 0.53) and stenosis resolution rate. Fifty-three cases developed SUI after urethroplasty, with a pooled rate of 19% (95%CI: 10-31%). Urethroplasty after RIUS is effective in 80% of cases, independently of previous RT modality or urethroplasty technique, but one in every 5 patients develop SUI after procedure.