Analysis of the urethral stricture score and patient-related factors as predictors of outcomes following oral mucosal graft urethroplasty

Objective: The complexity of urethral strictures can predict outcomes following urethroplasty. The previously described urethral stricture score (U score) considered only stricture-related factors to grade the complexity of urethral strictures and to predict recurrence post urethroplasty, but not considered patient-related factors for the same. We aimed to study the correlation of both of these factors to the outcomes of oral mucosal graft urethroplasty. Methods: We retrospectively reviewed data of 101 patients who underwent oral mucosal graft urethroplasty in our institute with a minimum follow-up of 6 months. Baseline patient characteristics and stricture-related parameters were noted. The U score was calculated for all patients which consisted of the length, location, number, and etiology of stricture. Univariate and multivariate Cox proportional hazard regression models were used to determine significant risk factors of recurrence. Results: The mean follow-up of patients was 15 months. Recurrence was seen in 28 patients and the mean time for detection of recurrence was 8 months of follow-up. The Charlson Comorbidity Index, history of previous intervention, length of strictures, location of strictures, number of strictures, history of smoking, and etiology were independent predictors of recurrence following urethroplasty. Based on these parameters, we formulated the modified U score (MU score). The scores ranged from 0 to 6 and a score of >2 was found to be predictive of recurrence. On comparing receiver operating characteristic curves for both scores by the DeLong test, the MU score had larger area under the curve than the U score. Conclusion: The MU scoring system is the first of its kind attempt taking into consideration both patient- and stricture-related factors to predict recurrence following oral mucosal graft urethroplasty.