Christine Sullivan
PENETRATING TRAUMA TO THE FLANK
PATHOPHYSIOLOGY
The flank is the area between the anterior and posterior axillary lines, from the sixth rib to the iliac crest.
Any intraperitoneal or retroperitoneal structure may be injured. Missile pathways are unpredictable, and the appearance of stab wounds can be misleading.
CLINICAL FEATURES
Patients may present with hemorrhagic shock, peritonitis, evisceration, or an innocuous-appearing wound with stable vital signs.
Gross blood on digital rectal examination indicates bowel injury.
Blood at the urethral meatus or hematuria suggests genitourinary injury.
DIAGNOSIS AND DIFFERENTIAL
Wound exploration is of limited value.
CT is the diagnostic study of choice in hemodynamically stable patients. Double-contrast (PO and IV) studies, with the addition of rectal contrast when there is suspicion of rectal or sigmoid colon injury, is recommended.
EMERGENCY DEPARTMENT CARE AND DISPOSITION
Follow standard resuscitation protocols, including immediate surgical consultation.
Emergent laparotomy is indicated when patients are hemodynamically unstable and have peritonitis, and in patients with most flank gunshot wounds. Many stab wounds can be managed conservatively.
Give broad-spectrum antibiotics (eg, piperacillintazobactam 3.375 grams IV) if the patient has peritonitis.
In stable patients, utilize CT to determine the need for operation and to detect occult injuries. CT can often determine the exact depth of stab wounds. High-risk stab wounds (penetration beyond the deep fascia) require surgical consultation and admission.
Admit all patients for observation with the exception of those sustaining low-risk stab wounds (superficial to deep fascia). Patients with low-risk stab wounds whose diagnostic evaluation reveals no injury can be discharged if stable after observation for several hours.
PENETRATING BUTTOCK INJURIES
PATHOPHYSIOLOGY
Operative intervention is rarely required for stab wounds to the buttock.
CLINICAL FEATURES
Approximately 30% of patients with gunshot wounds to the buttock require surgical intervention. An entrance wound above the level of the greater trochanters or a transpelvic or transabdominal bullet trajectory predicts the need for laparotomy.
Gross hematuria is associated with the need for surgery.
Perform a rectal examination for gross blood.
Evaluate the lower extremities for vascular or neurologic injury, including special attention for sciatic and femoral nerve injury.
DIAGNOSIS AND DIFFERENTIAL
Wound exploration is of limited value except in very superficial stab wounds to detect gross foreign bodies.
Hemodynamically stable patients should undergo CT with oral, intravenous, and rectal contrast.
Proctosigmoidoscopy can be performed if blood is noted on rectal examination or if the missile pathway suggests possible rectal injury.
A cystourethrogram (either as a separate study or in conjunction with CT scanning) can be performed in patients with hematuria or wounds near the genitourinary tract.
CT angiography or traditional angiography and venography may be indicated if pelvic hematoma is found on CT.
Plain abdominal or pelvic radiographs can help determine missile pathway and detect fractures.
EMERGENCY DEPARTMENT CARE AND DISPOSITION
Follow standard resuscitation protocols, including immediate surgical consultation.
Emergent laparotomy is indicated when patients are hemodynamically unstable, have peritonitis, or have an intrapelvic or transabdominal bullet path.
Give broad-spectrum antibiotics (eg, piperacillin-tazobactam 3.375 grams IV) if the patient has symptoms concerning for peritonitis.
If no immediate indication for laparotomy is found, utilize CT to determine the need for operation and to detect occult injuries.
Admit all patients for observation with the exception of those sustaining very superficial stab wounds whose diagnostic evaluation reveals no significant injury.
For further reading in Tintinalli’s Emergency Medicine: A Comprehensive Study Guide, 7th ed., see Chapter 261, “Penetrating Trauma to the Flank and Buttocks,” by Alasdair K.T. Conn.