This tab covers the reconstructive management of pelvic fracture urethral injuries (PFUI). (The acute trauma management is covered in the Trauma topic.)
Pathogenesis
PFUIs result from blunt pelvic trauma and accompany ≈10% of pelvic fractures. Distraction injuries are unique to the membranous urethra, most often occurring where the bulbous urethra departs the membranous urethra. (By contrast, straddle injuries usually involve only the bulbar urethra.)
Diagnosis and Evaluation
Define the precise anatomy before reconstruction. A cystogram shows the rostral displacement of the proximal urethra, the bladder outline, and bladder-neck competency — contrast in the prostatic urethra suggests an incompetent (open) bladder neck, while its absence suggests a competent (closed) one. However, the bladder-neck appearance on imaging does not reliably predict its ultimate post-reconstruction function, so videourodynamics can be used; a truly incompetent open bladder neck may warrant a continent stoma rather than urethroplasty.
Management
Most PFUIs are short and amenable to mobilisation of the corpus spongiosum with a primary anastomosis. Mobilisation is done cautiously because the retrograde blood supply is tenuous in pelvic-fracture patients; meticulously detaching Buck's fascia increases corporeal compliance and limits the need for aggressive mobilisation. The proximal anterior urethra can be anastomosed to any posterior segment.
- Positioning — the exaggerated lithotomy/perineal approach, with boots positioned to avoid stretching the common peroneal (fibular) nerve (injury causes foot drop). Operatively, the ischiocavernosus is divided, the corpus spongiosum and bulbospongiosum are detached, the intracrural space is developed, and a spatulated, tension-free anastomosis (10–12 sutures) is made over a soft silicone stent. (The source's detailed step-by-step dictation is condensed here to its principles.)
- For a markedly rostrally distracted proximal urethra, be prepared to escalate: corpus-spongiosum mobilisation, intracrural-space development, sequesterectomy (removal of scar), corporeal rerouting, and infrapubectomy — the last risks penile shortening, erectile destabilisation, and pelvic instability/chronic pain.
- Postoperative care — urine is diverted by suprapubic cystostomy with the urethral catheter serving only as a stent; bed rest for 24–48 h, then ambulation. A voiding trial with contrast at 3–4 weeks checks for extravasation and patency before the suprapubic catheter is removed, with flexible endoscopy at ~6 months and 1 year.
- Outcomes — curative rates are in the high 90% range. Failures reflect ischemia of the mobilised proximal corpus spongiosum; duplex ultrasound predicts those at risk, and patients with bilateral internal pudendal obstruction may need penile arterial revascularisation before reconstruction. Erectile dysfunction is often a consequence of the injury itself.
Self-Test
1. Which part of the urethra is most commonly affected in a straddle injury versus a distraction injury? Straddle injury — the bulbar urethra; distraction injury — the membranous urethra (at the bulbomembranous junction).
2. A patient has foot drop after a urethroplasty. Which nerve is affected, and what is its sensory function? The common peroneal (fibular) nerve, supplying sensation over the posterolateral leg and the knee joint.
3. If the proximal urethra is markedly rostrally distracted, which maneuvers help achieve a tension-free anastomosis? Corpus-spongiosum mobilisation, development of the intracrural space with detachment of the bulbospongiosum, sequesterectomy, corporeal rerouting, and infrapubectomy.