Posterior urethra disruption with immediate draining of contrast medium by the internal iliac venous system

Clinical History

A 19-year-old male after a straddle injury presented with complaints of bleeding at the urethral meatus and an inability to void.

Imaging Findings

This case concerns a 19-year-old male, who after a straddle injury presented with complaints of bleeding at the urethral meatus and an inability to void. This patient had inadvertently fallen backwards and an acutely shaped piece of iron had wounded the perineum, especially the posterior urethra. An ascending urethrography was immediately performed, which revealed a posterior (bulbar) urethra disruption (Fig. 1) with immediate draining of contrast medium by the internal iliac venous system (Fig. 2), perhaps due to corpus spongiosum rupture. No pelvic fracture was discernible. A suprapubic catheter was the first therapeutic approach. After two weeks, the patient was reexamined and a minor leak was evident at the ascending urethrography (Fig. 3).

Discussion

Posterior urethral injury or bladder rupture is seen in 20% of the major pelvic ring disruptions. Males with pelvic fractures also suffer from urethral injuries in 10%. Urethral injuries rarely occur without the presence of pelvic fractures. Urethral disruptions must be diagnosed as soon as possible after the admission of a patient, as an immediate diagnosis provides a better outcome (1). The Goldman classification system (2) is as follows: Type I injury: The posterior urethra is stretched and elongated but intact. The prostate and bladder apex are displaced superiorly due to disruption of the puboprostatic ligaments and the resulting hematoma. Type II injury: Disruption of the urethra occurs above the urogenital diaphragm. The membranous urethra is intact. Type III injury: The membranous urethra is disrupted with extension of injury to the proximal bulbous urethra and/or disruption of the urogenital diaphragm. Type IV injury: Bladder neck injury with extension into the proximal urethra. Type IV A injury: Injury of the base of the bladder with periurethral extravasation simulating a true Type IV urethral injury. Type V injury: Partial or complete pure anterior urethral injury. Retrograde urethrography is widely accepted as the primary investigation of choice. An IVP is inadequate for the evaluation of the bladder and urethra after trauma, because of dilution of the contrast material within the bladder and because the resting intravesical pressure is simply too low to demonstrate a small tear. It is also known that a routine CT cannot always rule out bladder or urethral injury (3). Often the first therapeutic procedure for men with posterior urethral injury secondary to pelvic fracture is placement of a suprapubic catheter for bladder drainage and subsequent delayed repair. The ultimate repair of the posterior urethral injury can be performed 6–12 weeks after the accident. Through a perineal approach, the urethra is mobilized distally to allow a direct anastomosis after excision of any stricture. A urethral catheter is left indwelling to stent the repair, and removal of the suprapubic catheter is optional. Transpubic approaches for this repair have also been described and may be useful in men with fistulous tracts complicating a membranous urethral injury (4).

Differential Diagnosis List

Final Diagnosis

Posterior urethra disruption.

URL:	https://eurorad.org/case/3219
DOI:	10.1594/EURORAD/CASE.3219
ISSN:	1563-4086