Verletzungen der Urethra

Teenager in
an MVA with pelvic pain and vaginal bleeding. Axial CT with contrast of the lower pelvis (above left) shows a contrast-fluid level in the bladder in the anterior part of the pelvis along with a fluid-filled vagina in the middle of the pelvis that lies anterior to the rectum. There is also free fluid noted around the bladder. At a lower level in the CT (below left) the left wall of the vagina is seen to be completely disrupted and discontinuous. AP image from the voiding phase of a voiding cystourethrogram exam obtained a month later (right) shows contrast leaking out of the left side of the urethra.The diagnosis was vaginal laceration with associated urethral laceration.
pediatricimaging.org • CC-by-nc-sa 4.0
Teenager with
pelvic fracture from trauma who cannot void. AP (upper left) and oblique (upper right) images from a voiding cystourethrogram with the bladder filled through a suprapubic catheter shows extravasation of contrast into the base of the penis when the patient attempts to void. Oblique image from a retrograde urethrogram (below) shows an inability to fill the urethra completely during retrograde injection.The diagnosis was urethral transection confirmed at cystoscopy.
pediatricimaging.org • CC-by-nc-sa 4.0
Teenager with
enuresis. Transverse US of the prostatic urethra (upper left) shows a small round echogenic lesion with posterior shadowing in the center of the prostatic urethra which was not seen in the transverse US of the penile urethra (upper right). Sagittal US of the bladder (lower left) shows an echogenic lesion with posterior shadowing in the posterior aspect of the bladder that on transverse US of the bladder (lower right) resolved into two separate echogenic lesions with posterior shadowing.The diagnosis was urethral trauma due to a metal axle from a toy car the patient had inserted into his urethra years before which had perforated the bladder creating a colovesical fistula and caused development of two bladder stones.
pediatricimaging.org • CC-by-nc-sa 4.0
Radiopaedia • CC-by-nc-sa 3.0 • de

Urethral injuries can result in long-term morbidity and most commonly result from trauma. The male urethra is much more commonly injured than the female urethra and is the focus of this article.

Clinical presentation

In the setting of trauma, the classic triad of blood of the external urethral meatus or vaginal introitus may be seen but is an unreliable sign, as is hematuria. Inability to void may be seen in complete urethral disruption. Examination may reveal blood on digital rectal exam and perineal ecchymosis.

Dysuria, urinary urgency and suprapubic discomfort can ensue in the chronic stages of incomplete urethral injury due to complicating strictures.

Pathology

Male urethral injuries are divided into anterior (penile/bulbar) and posterior (membranous/prostatic) urethral injuries. Injuries, of course, may be partial or complete. There are a variety of causes:

  • blunt trauma: due to shearing/straddle injuries
    • posterior urethral injury is caused by a crushing force to the pelvis (e.g MVC) and is associated with pelvic fractures (~10%) and bladder injury
    • anterior urethral injury is usually caused by a straddle injury and is an isolated injury
  • penetrating trauma: e.g. stab wounds, gunshot wounds, dog bites
    • more commonly affect the anterior urethra
  • iatrogenic
Classification

See: Goldman classification of urethral injuries.

Radiographic features

Fluoroscopy

Voiding cystourethrography is the most appropriate way to evaluate the posterior part of the male urethra and injuries to the female urethra.

Retrograde urethrography is the modality of choice to investigate the anterior part of the urethra. It will demonstrate extraluminal contrast, which has extravasated from the urethra at the site of injury. It is important to determine if this is above the urogenital diaphragm (anterior) or below (posterior) it. Patients with incomplete injuries may represent subsequently with strictures.

The extent of injury can be categorized:

  • contusion
    • radiographically normal
  • partial disruption
    • extravasation of contrast with maintenance of normal urethral continuity
  • complete disruption
    • extravasation of contrast with loss of urethral continuity and lack of proximal urethral filling
CT

CT cystography can be performed but this is much less specific for urethral vs. bladder injury. Other features of urethral injury include retropubic and perivesical hematoma and obscuration of the urogenital fat plane.

Treatment and prognosis

Treatment consists from urinary diversion (e.g. suprapubic catheter) to primary or delayed urethral anastomosis depending on the severity (i.e. tear vs. complete rupture) of the injury. Urethral stricture is the most common long-term complication.

Siehe auch:
Assoziationen und Differentialdiagnosen zu Verletzungen der Urethra:
Penisfraktur
 
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vaginale
Verletzungen
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