Could the bulbar urethral end location on the cystourethrogram predict the outcome after posterior urethroplasty for pelvic fracture urethral injury?

Objectives: To identify cystourethrogram (CUG) findings that independently predict the outcome of posterior urethroplasty (PU) following pelvic fracture urethral injury (PFUI). Methods: Findings of CUG included the location of the proximal end of the bulbar urethra in zones A (superficial) or B (deep) according to its relationship with the pubic arch. Others included the presence of pelvic arch fracture, bladder neck, and posterior urethral appearance. The primary outcome was the need for reintervention either endoscopically or by redo urethroplasty. Independent predictors were modeled using a logistic regression model and a nomogram was constructed and internally validated using 100-bootstrap resampling. Time-to-event analysis was performed to validate the results. Results: A total of 196 procedures in 158 patients were analyzed. The success rate was 83.7% with 32 (16.3%) procedures requiring direct vision internal urethrotomy, urethroplasty, or both in 13 (6.6%), 12 (6.1%), and 7 (3.6%) patients, respectively. On multivariate analysis, bulbar urethral end located at zone B (odds ratio [OR]: 3.1; 95% confidence interval [CI]: 1.1-8.5; p = 0.02), pubic arch fracture (OR: 3.9; 95%CI: 1.5-9.7; p = 0.003), and previous urethroplasty (OR: 4.2; 95% CI: 1.8-10.1; p = 0.001) were independent predictors. The same predictors were significant in the time-to-event analysis. The nomogram discrimination was 77.3% and 75% in the current data and after validation. Conclusions: The location of the proximal end of the bulbar urethra and redo urethroplasty could predict the need for reintervention after PU for PFUI. The nomogram could be used preoperatively for patient counseling and procedure planning.