Characterization of a Standardized Postoperative Radiographic and Functional Voiding Trial after 1-Stage Bulbar Ventral Onlay Buccal Mucosal Graft Urethroplasty and the Impact on Stricture Recurrence-Free Survival

PURPOSE: We sought to characterize a standardized postoperative radiographic and functional voiding trial, and determine its impact on outcomes after substitution urethroplasty.

MATERIALS AND METHODS: This is an observational, monocenter study of men who underwent 1-stage ventral onlay buccal mucosal graft urethroplasty for bulbar urethral stricture between January 2009 and December 2016. Patients were stratified by voiding trial success vs failure, including radiographic (extravasation or residual narrowness) and functional (post-void residual volume greater than 100 ml) failure, 21 days postoperatively. End points were voiding trial failure and recurrence-free survival. Regression models were created to determine risk factors of voiding trial failure and evaluate the impact of voiding trial failure on recurrence.

RESULTS: The voiding trial succeeded and failed in 437 (85.2%) and 76 (14.8%), respectively, of 513 men. Of the latter men 54 (71.1%) showed evidence of extravasation and 22 (28.9%) had residual narrowness or functional failure. On multivariable logistic regression analyses no preoperative predictor of voiding trial failure was found (all p >0.05). At a median followup of 32 months Kaplan-Meier analyses (log rank test p = 0.033) and multivariable Cox regression analyses (HR 1.86, p = 0.037) revealed an association of voiding trial failure and stricture recurrence. When further stratifying voiding trial failure, residual narrowness or functional failure (HR 4.60, p <0.001) but not extravasation (HR 1.08, p = 0.9) was a risk factor for recurrence. Limitations include the retrospective assessment of investigated end points.

CONCLUSIONS: Residual narrowness or functional failure at an early voiding trial after buccal mucosal graft urethroplasty may predict stricture recurrence. Identifying intraoperative complexity factors predicting initial voiding trial failure might be a key to identifying those individuals with early recurrence.