Reconstructive Urethral Surgery
Reconstructive Urethral Surgery
9 The Acute Posterior Urethral Injury (p. 69-71)
Posterior urethral disruption and distraction injuries present the most devastating and formidable challenges to the reconstructive urologic surgeon dealing with urinary tract trauma. Subprostatic pelvic fracture urethral distraction defects represent a traumatic disruption in continuity with minimal loss of urethra but with displacement of the two ends in the anteroposterior or cephalocaudal planes. Historical reports of surgical care of this injury are replete with management techniques resulting in lifelong sequelae of recurrent stricture, incontinence, and erectile dysfunction.
The development and refinement of anastomotic techniques to restore continuity to the urethra, magnetic resonance imaging to identify and define the injury, duplex ultrasound to avoid and understand the vascular injuries, and a revised classification have impacted and affected the successful outcomes now achieved in resolving this injury. The long-standing controversy surrounding initial management by early intervention with primary realignment vs delayed surgical repair after preliminary cystotomy diversion remains a contentious debatable issue, with reported success with alignment over a stenting catheter varying between 15% and 94% . Advocates of either approach to surgical care of this injury have traditionally focused on the development of impotence and incontinence as a potential complication of the surgical technique. However, it is increasingly evident that the length of the distraction defect and subsequent development of incontinence and impotence are related more to the severity of the injury and the extent of the anatomical disruption, both bony and soft tissue, rather than the surgical approach itself [2, 3].
9.1 Anatomy and Pathogenesis of the Urethral Injury
Pelvic fractures are the major source and etiology of posterior urethral distraction injuries, occurring at a rate of 20 per 100,000 population. Motor vehicle and motorcycle injuries are associated with the highest incidence of pelvic fractures (15.5%) followed by pedestrian injuries (13.8%), falls from heights greater than 15 ft (13%), car occupants (10.2%), and occupational crush trauma (6%). The majority of injuries occur in the first four decades, with a mean age of 33 years including an 8% pediatric occurrence (<,12 years). Pelvic fractures are a marker of severe post-traumatic injury and are associated with intra-abdominal and urogenital injuries in 15%–20% of patients. The most commonly injured organ in pelvic fractures is the posterior urethra (5.8%–14.6%), followed closely by the liver (6.1%–10.2%) and the spleen (5.2%–5.8%) .
The bladder and bladder neck are frequently involved, and injury to these structures needs to be identified and included in the equation of the surgical strategy. Associated perforation injury of the rectum is critical to identify but rarely seen with pelvic fracture trauma . The life-threatening injuries take precedence in diagnosis and management over the urethral injury, but in those patients who survive, the urethral injury will be the source of chronic complex disability and morbidity. Urinary incontinence in the male depends on the bladder neck proximally and the external sphincter distally. The distal external sphincter mechanism may be destroyed by this posterior urethral injury or during subsequent reconstruction and continence will, therefore, be dependent on bladder neck function alone. Most men, however, are continent following repair of this injury and will reveal a closed bladder neck on preoperative cystography and cystoscopy. A few patients will be noted to have a persistently open, funneled bladder neck or a bladder neck quadrant scar seen on transvesical cystoscopy, which support the potential of a concomitant bladder neck