Genitourinary (GU) injuries frequently occur in the setting of polytrauma, so a thorough evaluation is necessary to avoid missing significant injuries.
Injuries should be suspected with any blunt or penetrating trauma near the GU tract, including any rapid deceleration, which can cause major vascular or parenchymal injury even without specific signs or symptoms. Hematuria of any amount raises the index of suspicion for GU injury, and difficulty with urination can be due to bladder or urethral injury or associated concomitant spinal cord injury. Flank contusions or hematomas, evidence of lower rib fractures, or penetrating flank injuries raise concern for renal injury. Lower abdominal pain, tenderness, ecchymosis, or evidence of a pelvic fracture as well as perineal or scrotal edema are consistent with possible bladder injury. Vaginal bleeding, a high-riding prostate, a perineal hematoma, and/or blood at the urethral meatus are concerning for urethral disruption.
DIAGNOSIS AND DIFFERENTIAL
There is no direct relationship between the degree of hematuria and the severity of renal injury. There is some evidence that microscopic hematuria in patients with a blood pressure <90 mm Hg or any gross hematuria is associated with a more significant renal injury. In children where renal trauma is being considered, isolated microscopic hematuria with <50 red blood cells per high-powered field makes a significant renal injury less likely. An IV contrast-enhanced abdominal/pelvic CT scan is the imaging “gold standard” for the stable trauma patient with a suspected kidney injury. A 10-minute delayed image is needed to ascertain whether there is any urine extravasation but can be omitted if the kidney is normal and there are no fluid collections. A retrograde cystogram (plain film or CT) is the “gold standard” for demonstrating bladder injury, and a retrograde urethrogram is indicated for demonstrating urethral injuries. Color Doppler ultrasonography is the preferred imaging technique for investigating closed scrotal and testicular injuries. A focused assessment with sonography in trauma (FAST) exam can detect intra-abdominal fluid collections but cannot reliably evaluate renal, bladder, or ureteral injuries Table 167-1.
Imaging for Genitourinary Trauma
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Imaging for Genitourinary Trauma
|Injury ||Imaging ||Comments |
|Multisystem trauma or suspected renal parenchymal or vascular injury ||Abdominal-pelvic IV contrast CT scan || |
Include pelvis to view entire GU tract
Delayed films needed to identify urinary extravasation
|Any visceral injury resulting in free intraperitoneal fluid ||FAST ||Identifies free fluid, but does not specify type of visceral injury and does not identify renal vascular injury |
|Renal artery injury ||Renal angiography ||Details vascular injuries |
|Ureteral injury ||Abdominal-pelvic IV contrast CT scan ||Delayed films needed to identify extravasation; obtain IV pyelogram or retrograde pyelogram if still suspicious with negative CT |
|Bladder injury ||Retrograde cystogram ||Can use plain radiographs or CT scan |
|Urethral injury ||Retrograde urethrogram ||Discuss sequencing with radiologist, because if performed prior to abdominal-pelvic contrast ...|