Pediatric emergency medicine trisk 3326 3326
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In boys, the urethra is divided by the urogenital diaphragm into an
anterior urethra (pendulous and bulbous) and a posterior urethra
(membranous and prostatic) ( Fig. 108.4 ). Anterior and posterior
urethral injuries differ from each other by mechanism of injury, clinical
presentation, and treatment.
The major sign of acute anterior injury is bleeding from the urethra.
Urethral injury should be suspected when there is blood at the meatus,
hematuria, inability to void, displacement of the prostate on rectal
examination, and/or perineal ecchymosis. Blind placement of a urethral
catheter when urethral injury is suspected is discouraged as it may
theoretically convert a partial tear into a complete transection.
Current Evidence
Blunt trauma, due to motor vehicle accidents, high-velocity falls onto the
perineum, and straddle injuries, accounts for most urethral injuries sustained
during childhood. Injuries due to instrumentation and penetrating injuries, such as
gunshot wounds, are less common. Urethral injuries occur primarily in males.
Anterior urethral injuries result from direct trauma and are often isolated. The
pendulous urethra is well protected from injury when the penis is flaccid, but can
be damaged by blunt or penetrating forces. Bulbar injuries are more common and
most often result from straddle injuries, as the urethra is compressed between the
symphysis pubis and a solid object.
Posterior urethral injuries occur with severe trauma to the body and are usually
associated with other injuries, particularly pelvic fractures. Posterior urethral
injuries in men almost uniformly occur distal to the prostate. In adults, the mature
prostate, puboprostatic ligament, and bladder stabilize the prostatic urethra,
making it less susceptible to trauma. When this occurs, the urethra is usually
sheared at the level of the urogenital diaphragm with separation of the prostate
from the membranous urethra or the bulbar urethra from the membranous urethra.
The mortality rate with fractured pelvis has been reported to be as high as 30%.
Injuries to the prostatic urethra may extend to the bladder neck.
Female urethral injuries are commonly divided into avulsions and longitudinal
tears. These injuries occur most often from blunt abdominal trauma in motor
vehicle accidents and in association with pelvic fractures. Injuries may also occur
after surgical procedures or instrumentation. The diagnosis is missed on initial
assessment in up to 40% of patients, emphasizing the need for careful physical
examination and diagnostic evaluation.
