Pubourethral Stump Angle Measured on Preoperative Magnetic Resonance Imaging Predicts Urethroplasty Type for Pelvic Fracture Urethral Injury Repair

To examine whether the type of delayed urethroplasty required for pelvic fracture urethral injury, which is not easily predicted from conventional urethrography findings, can be predicted from preoperative magnetic resonance imaging (MRI) results. Records of 74 male patients with pelvic fracture urethral injury who underwent MRI of the pelvis at least 3 months after injury and, subsequently, delayed anastomotic urethroplasty were retrospectively analyzed. Pubourethral stump length (PUL) was defined as the distance between the distal end of the proximal urethral stump and the lower border of the inferior pubic ramus. Pubourethral stump angle (PUA) was defined as the angle between the long axis of the pubis and the line between the distal end of the proximal urethral stump and the lower border of the inferior pubic ramus. Both PUL and PUA were measured in sagittal T2-weighted MRI. Delayed urethroplasty was performed by a simple perineal approach in the 28 patients requiring only bulbar urethral mobilization with or without corporal splitting and by elaborate approach in the 46 additionally requiring inferior pubectomy or an abdominoperineal approach with urethral rerouting. The overall success rate defined as no recurrent stricture on urethroscopy was 94.6%. Disruption at the prostate apex, greater urethral gap length, longer PUL, and lower PUA were in univariate analysis significantly associated with an elaborate approach. In multivariate analysis, only low PUA was an independent predictor of the need for an elaborate approach. PUA measured on MRI is useful for predicting the type of reconstruction needed for urethral repair.