eMedicine Specialties > Emergency Medicine > Trauma & Orthopedics

Trauma, Lower Genitourinary

Author: Imad S Dandan, MD, Consulting Surgeon, Department of Surgery, Trauma Section, Scripps Memorial Hospital
Coauthor(s): Walid Farhat, MD, Fellow, Department of Surgery, Division of Urology, The Hospital for Sick Children at Toronto
Contributor Information and Disclosures

Updated: Apr 16, 2009

Introduction

Background

Injuries to the lower genitourinary (GU) tract alone are not life threatening, but their association with other potentially more significant injuries necessitates an organized approach to diagnosis and management. Because trauma is a multisystem disease, multiple injuries may be present in the trauma patient. Other injuries often take priority over injuries to the GU system and may initially interfere or postpone a complete urologic assessment. Coordinated efforts between various services caring for the patient are crucial to ensure comprehensive care.

Initial evaluation of the injured patient suspected to have GU trauma should not differ from that of other trauma patients. Follow the protocols of the Advanced Trauma Life Support program of the American College of Surgeons.

Pathophysiology

The lower GU tract comprises the urinary bladder, urethra, and external genitalia.

Most bladder injuries occur in association with blunt trauma. Eighty-five percent of these injuries occur with pelvic fractures, with the remaining 15% occurring with penetrating trauma and blunt mechanism not associated with a pelvic fracture (ie, full bladder blowout).

Urethral injury is predominantly a male problem. In males, the urethra is divided into the proximal (posterior) segment and the distal (anterior) segment by the urogenital diaphragm. The anterior urethra is further divided into membranous (sphincteric) and prostatic segments. About 3 cm long, the posterior urethra extends from the bladder to the urogenital diaphragm.

Injuries to the posterior urethra are mostly secondary to pelvic fractures, while injuries to the anterior urethra are caused by straddle-type (eg, bicycles, skateboards) or penetrating (often self-inflicted) injuries. Urethral injuries from trauma constitute only 10% of all GU injuries, with iatrogenic etiology constituting a significant fraction of all urethral injuries.

Injuries to the external genitalia (ie, the penis and the scrotum) are usually secondary to injuries caused by penetration, blunt trauma, continence- or sexual pleasure–enhancing devices, and mutilation (self-inflicted or otherwise).

Frequency

United States

Three to ten percent of all trauma patients have injuries involving the GU tract, while 10-15% of trauma patients with abdominal injuries have associated GU tract involvement. Urethral injuries constitute 10% of all injuries to the GU tract, with bladder injuries comprising another 40%.

Mortality/Morbidity

Mortality from lower GU trauma is attributed to associated injuries, especially pelvic fractures.

Sex

Urethral trauma is primarily a male problem.

Age

Urethral trauma affects all age groups but seems to have a higher incidence in persons aged 15-25 years.

Clinical

History

In blunt trauma, history is obtained regarding the time and mechanism of injury, eg, the position of the patient in a motor vehicle accident (MVA) and whether restraints were used. The speed of the vehicle and the manner in which the accident occurred provide information about forces applied to the victim.

In penetrating trauma, knowing the size of the stabbing weapon or the caliber of the gun and the distance from which it was discharged helps in assessment. Question paramedics as to the condition of the patient immediately after injury occurred and during transport to the care facility.

In patients with GU trauma, symptoms are nonspecific and may be masked by or attributed to other injuries.

• Bladder trauma
  • In the ED, question the patient about suprapubic abdominal pain and the ability to void after the injury.
  • If the patient cannot provide such information and gross hematuria is present, suspect bladder injury.
• Urethral trauma
  • Knowledge of associated injuries that can cause urethral injury is required for diagnosis.
  • A history of inability to void indicates the possibility of urethral trauma.
• In external genitalia trauma, a history of psychiatric problems, use of penile rings, and excessive sexual activity is pertinent in specific conditions. A history of sudden pain, loss of erection, and swelling is important.

Physical

Signs of lower GU injury are a small part of a massive conglomeration of signs related to associated injuries; therefore, always keep a high index of suspicion.

• Bladder trauma
  • Bruising or edema of the lower abdomen, perineum, or genitalia indicates bladder injury.
  • Always suspect urethral and bladder injuries in patients with pelvic fractures and inability to void.
  • Inability to retrieve all fluid used to irrigate the bladder through a Foley catheter indicates bladder injury.
• Urethral trauma
  • The classic sign is blood at the meatus.
  • Penile or perineal edema and/or hematoma are present in anterior injuries.
  • A distended bladder may be present in posterior injuries, as 65% of posterior injuries are complete transections.
• Penile trauma
  • Loss of skin
  • Edema
  • Angulation
  • Level of mutilation
  • Viability of mutilated segment
• Scrotal trauma
  • Edema
  • Loss of skin
  • Discoloration
  • Condition of testes

Causes

Bladder injuries are best classified as intraperitoneal and extraperitoneal. Extraperitoneal bladder injuries account for 65-85% of bladder injuries and are usually associated with pelvic fractures, especially pubic ramus fractures (95%). Intraperitoneal bladder injuries account for 15-35% of bladder injuries and are infrequently associated with pelvic fractures. These injuries may be due to blunt rupture of a distended bladder or penetrating injury.

Blunt trauma is responsible for 60% of urethral injuries, and penetrating and iatrogenic etiologies cause 40%. Blunt injury in the anterior urethra usually is caused by a straddle-type mechanism compressing the urethra between a hard object and the symphysis pubis. In 70% of patients, penetrating trauma to the anterior urethra involves the perineum and bulbar urethra, and in 30%, the pendulous urethra is involved.

Posterior urethral injury in blunt trauma is secondary to pelvic fractures because of proximity to the bony pelvis. Missiles and knives can also cause penetrating injury to the posterior urethra.

In gunshot wounds, look for associated injuries to the pelvis, bladder, rectum, and sphincter mechanism.

• Main causes of bladder injuries
  • MVAs
  • Bicycle accidents
  • Stabbings
  • Impalements
  • Gunfire
  • Iatrogenic
• Main causes of urethral injuries
  • Straddle-type mechanism (eg, bicycles, skateboards, falls onto the perineum)
  • MVAs
  • Mutilation (self-inflicted or otherwise)
  • Gunfire
  • Stabbings
  • Iatrogenic

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