Upper Urinary Tract Injuries

1

What is the most common type of renal trauma in the United States, blunt or penetrating?

Approximately 90% of renal injuries are caused by blunt mechanism in the United States.

2

Why are pediatric patients more susceptible to major renal injuries?

Pediatric patients have weaker abdominal muscle, less ossified thoracic cage, decreased perirenal fat, and increased renal size in relation to the rest of the body.

3

When should a patient be investigated for renal trauma?

All blunt trauma patients with gross hematuria or those with shock and microscopic hematuria should be investigated for renal injuries. For penetrating trauma, all patients with hematuria (gross or microscopic) should be investigated.

4

When does one suspect renal trauma?

The mechanism of injury and physical examination will raise the suspicion for renal trauma. Flank ecchymosis, location of penetrating wounds, associated injuries (e.g., rib fracture), gross hematuria, and hypovolemic shock are things associated with renal injuries. Patients with anatomic renal abnormalities (e.g., hydronephrosis, ureteropelvic junction obstruction, ectopic kidney) can have hematuria out of proportion to the history of renal trauma. Injury to the renal hilum can cause little or no hematuria despite a severe injury.

5

What imaging study is the best to evaluate renal trauma?

Computerized axial tomography (CAT) scan of the abdomen and pelvis with intravenous (IV) contrast is the best image modality to investigate renal trauma. Delayed images (excretory phase) should be performed to delineate the collecting system and ureters.

6

When do you perform a single-shot intravenous pyelogram (IVP)?

The single-shot IVP can be used in patients when a CAT scan could not be performed before surgical exploration (e.g., shock). This image study is not adequate to diagnose and classify renal and ureteral injuries; however, it can help to determine the presence of contralateral kidney. A single film is taken 10 minutes after the administration of 2 mg/kg of contrast (max 150 mg).

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