Anastomotic Urethroplasty is Associated with a Lower Risk of Stricture Recurrence Compared to Buccal Mucosa Graft Onlay after Reconstruction for Radiation-Induced Bulbomembranous Urethral Stenosis

INTRODUCTION: The preferred treatment of bulbomembranous urethral stenosis (BMUS) after prostate cancer radiotherapy remains unclear. The purpose of this study is to examine the association of surgical technique and outcomes after urethroplasty for radiation induced BMUS. METHODS: From 01/2001-09/2024, a review of patients undergoing posterior urethroplasty for BMUS at two centers was performed. The primary outcome was stricture recurrence defined as stricture <16Fr confirmed on cystoscopy. Secondary outcomes included 90-day complications (Clavien ≥2), patient-reported satisfaction, de novo erectile dysfunction, or incontinence. Cox regression was used to evaluate variables associated with stricture recurrence and Fisher's exact test was used for secondary outcomes. RESULTS: 212 patients with radiation induced BMUS were reconstructed with either anastomotic urethroplasty (163) or buccal mucosal graft (BMG) (49). Median stenosis length was 2.0 cm (IQR 2.0-3.0), median follow-up for patients without recurrence was 97 months (IQR 52-144), and etiology was brachytherapy (46%), EBRT (45%) or combination (9.0%). On Cox regression, BMG urethroplasty was independently associated with stricture recurrence (Hazard Ratio 3.43, 95%C.I. 1.03-11.47; p=0.046) while patient age (p=0.3), stenosis length (p=0.1), diabetes (p=0.7), smoking (p=0.5), obesity (p=0.6), and prior endoscopic treatments (p=0.6) were not. For BMG urethroplasty, the estimated cumulative risk of stricture recurrence at 1, 2, and 10 years was 17%, 18%, and 20% compared to 3.3%, 5.0%, and 6.8% for anastomotic urethroplasty (log-rank p=0.01). Techniques did not differ with respect to complications (10% versus 4.1%; p=0.3), satisfaction (90% versus 88%; p=0.6), erectile dysfunction (15% versus 8.2%; p=0.2), or incontinence (18% versus 18%; p=1.0). CONCLUSIONS: When technically feasible, anastomotic urethroplasty is associated with a lower risk of stricture recurrence compared to onlay with buccal mucosa when reconstructing radiation-induced bulbomembranous urethral stenosis without a higher risk of adverse events.