LAUSR

INTRODUCTION AND OBJECTIVE: Direct visual internal urethrotomy (DVIU) represents the most common surgical procedure for urethral strictures' repair. Nevertheless, since the selection of the patients, follow up criteria, and assessment of success and failure are not homogeneous, the evaluation of short and long-term outcomes after DVIU appear challenging. The aim of this retrospective study is to investigate the outcomes and identify the predictors of failure for DVIU as primary treatment for untreated bulbar urethral strictures, performing a multivariable analysis of the results of DVIU in a homogeneous series of patients who underwent a strict follow up after surgery. METHODS: A retrospective descriptive analysis on a cohort of patients who DVIU in a referral center for reconstructive urethral surgery was performed. Patients who underwent DVIU for untreated bulbar urethral strictures with a 12 months' follow-up were included. The primary outcome was treatment failure, defined as any postoperative instrumentation. All patients underwent preoperative evaluation using urine culture, uroflowmetry, post-void residual (PVR), retrograde urethrogram, voiding cystourethrogram, and urethral ultrasonography. Follow-up visits were scheduled every 4 months in the first year and every 6 months later including urine culture, uroflowmetry and PVR. Statistical analyses consisted of Kaplan-Meyer plots to depict treatment-failure free survival and univariate and multivariable Cox regression analysis to test the association between predictors and treatment failure. RESULTS: 136 patients were included. The median stricture length was 2 cm. Median follow-up was 55 months. At 5-years follow-up failure-free survival rate was 57%. At univariate analysis, presence of diabetes, non-idiopathic etiology, stricture length of 3-4 cm, and pre-operative maximum flow were significantly associated with treatment failure (p value <0.00001). These predictors were included at multivariable analysis, where pre-operative maximum flow was the only significant predictor of treatment failure. Patients were stratified into three groups based on pre-operative maximum flow: 5ml/s, 5-8 ml/s, 8 ml/s. Failure-free survival at 5 years after surgery was significantly different in the three groups: 31% vs. 53% vs. 83% (p<0.00001). Similarly, stratifying according to stricture length (1-2 cm vs. 2-3 cm vs. 3-4 cm), a significantly different treatment failure-free survival was observed at 5 years (71% vs. 51% vs. 39%; p<0.00001). CONCLUSIONS: The failure of internal urethrotomy for untreated bulbar urethral strictures depends on pre-operative maximum flow at uroflowmetry. Patients with pre-operative maximum flow>8ml/ s have a high rate of success, and patients with maximum flow<5 ml/ s have low chances of success. The success rates of DVIU as primary treatment in patients with stricture lengths of 1-2 cm compared to longer strictures was statistically significant, however the use of DVIU for untreated bulbar urethral stricture should be suggested only in selected cases.