Validation of the Pubourethral Stump Angle as a Predictive Parameter for Elaborate Anastomotic Urethroplasty in...

To validate the pubourethral stump angle (PUA), an MRI-based parameter, as a preoperative predictor of the need for an elaborate approach during delayed anastomotic urethroplasty (DAU) for pelvic fracture urethral injury (PFUI), using an independent cohort.

We retrospectively reviewed 184 consecutive male patients who underwent DAU for PFUI between August 2016 and August 2024 and had adequate preoperative pelvic MRI. Urethral anatomy was assessed by MRI using a standardized protocol. MRI parameters included PUA, urethral gap length, pubourethral stump length, lateral prostatic displacement, and dorsal venous complex patency. DAU was performed via a perineal approach with ancillary maneuvers applied stepwise: step 1 (bulbar urethral mobilization), step 2 (corporal separation), step 3 (partial pubectomy), and step 4 (supracrural rerouting). The approach was categorized as simple if completed up to step 2, and elaborate if step 3 or higher was required. Logistic regression was used to identify independent predictors, and predictive performance was assessed by the area under the ROC curve (AUC).

An elaborate approach was required in 70 (38.0%). On multivariate analysis, prior transurethral treatment (OR 2.77, 95% CI 1.16-6.65, p = 0.02) and smaller PUA (OR 0.95 per degree, 95% CI 0.94-0.98, p < 0.0001) were independent predictors. The combined model demonstrated good discrimination, with an AUC of 0.782.

Smaller PUA on MRI and a history of prior transurethral treatment independently predict the need for elaborate surgical maneuvers during DAU for PFUI. Incorporating PUA into preoperative assessment may enhance surgical planning, facilitate patient counseling, and improve preparedness.