A Systematic Review and Meta-analysis of Adjuncts to Minimally Invasive Treatment of Urethral Stricture in Men

Urethral stricture disease (USD) is initially managed with minimally invasive techniques such as urethrotomy and urethral dilatation. Minimally invasive techniques are associated with a high recurrence rate, especially in recurrent USD. Adjunctive measures, such as local drug injection, have been used in an attempt to reduce recurrence rates.To systematically review evidence for the efficacy and safety of adjuncts used alongside minimally invasive treatment of USD.A systematic review of the literature published between 1990 and 2020 was conducted in accordance with the PRISMA checklist.A total of 26 studies were included in the systematic review, from which 13 different adjuncts were identified, including intralesional injection (triamcinolone, n = 135; prednisolone, n = 58; mitomycin C, n = 142; steroid-mitomycin C-hyaluronidase, n = 103, triamcinolone-mitomycin C-N-acetyl cysteine, n = 50; platelet-rich plasma, n = 44), intraluminal instillation (mitomycin C, n = 20; hyaluronic acid and carboxymethylcellulose, n = 70; captopril, n = 37; 192-iridium brachytherapy, n = 10), application via a lubricated catheter (triamcinolone, n = 124), application via a coated balloon (paclitaxel, n = 106), and enteral application (tamoxifen, n = 30; deflazacort, n = 36). Overall, 13 randomised controlled trials were included in the meta-analysis. Use of any adjunct was associated with a lower rate of USD recurrence (odds ratio [OR] 0.37, 95% confidence interval [CI] 0.27-0.50; p < 0.001) compared to no adjunct use. Of all the adjuncts, mitomycin C was associated with the lowest rate of USD recurrence (intralesional injection: OR 0.23, 95% CI 0.11-0.48; p < 0.001; intraluminal injection: OR 0.11, 95% CI 0.02-0.61; p = 0.01). Urinary tract infection (2.9-14%), bleeding (8.8%), and extravasation (5.8%) were associated with steroid injection; pruritis of the urethra (61%) occurred after instillation of captopril; mild gynaecomastia (6.7%) and gastrointestinal side effects (6.7%) were associated with oral tamoxifen.Adjuncts to minimally invasive treatment of USD appear to lower the recurrence rate and are associated with a low adjunct-specific complication rate. However, the studies included were at high risk of bias. Mitomycin C is the adjunct supported by the highest level of evidence.We reviewed studies on additional therapies (called adjuncts) to minimally invasive treatments for narrowing of the urethra in men. Adjuncts such as mitomycin C injection result in a lower recurrence rate compared to no adjunct use. The use of adjuncts appeared to be safe and complications are uncommon; however, the studies were small and of low quality.