Membranous urethral length on magnetic resonance imaging as a novel predictor of urinary continence after delayed anastomotic urethroplasty for pelvic fracture urethral injury.

ABSTRACT

PURPOSE: We studied the impact of membranous urethral length (MUL) on magnetic resonance imaging (MRI) on post-urethroplasty continence in male patients with pelvic fracture urethral injury (PFUI). METHODS: Of 169 male patients with PFUI who underwent delayed anastomotic urethroplasty between 2008 and 2020, 85 who underwent preoperative MRI, had no recurrent stenosis on cystoscopy, and underwent a 1-h pad test 1 year after surgery were included. MUL was defined as the distance from the distal end of the disrupted proximal urethra to the apex of the prostate, as measured using T2-weighted MRI. Urinary incontinence (UI) was defined as a 1-h pad test weight > 2.0 g. RESULTS: None of the patients had UI before a pelvic fracture. Eighty-two patients (96.5%) had a measurable MUL, and the median length was 8.1 (interquartile range [IQR], 5.2-10.8) mm. The median weight of the 1-h pad test was 1.0 (IQR, 0.0-4.0) g, and 26 (30.6%) patients had UI. An open bladder neck (odds ratio [OR], 4.6; 95% confidence interval [CI], 1.0-22.0; p = 0.04) and a short measurable membranous urethra (for every extra mm OR, 1.2; 95% CI, 1.0-1.3; p = 0.04) were significant UI predictors on multivariate analysis. CONCLUSIONS: A long MUL is significantly positively associated with urinary continence in male patients with PFUI. This could be of potential value to reconstructive urologists when counseling patients regarding post-urethroplasty continence before urethroplasty.