A 25-year-old woman is brought to the emergency department with multiple gunshot wounds to her abdomen. Her blood pressure is 70 mm Hg. Her abdomen is massively distended. Large intravenous lines are placed, and a nasogastric tube and Foley catheter are inserted. The patient is brought immediately to the OR. After 2 L of normal saline, her blood pressure is 75/0 mm Hg, pulse rate is 140 bpm, and respiration rate is 30 breaths per minute. The next step in management should be which of the following?

Open the abdomen and use a large Richardson retractor to compress the abdominal aorta against the vertebrae just below the diaphragm. The advantages of occluding the subdiaphragmatic aorta (as opposed to the supradiaphragmatic aorta) are that it: (a) avoids opening another major cavity; and (b) results in less diminution of blood flow to the spinal cord and renal circulation. Further attempts to resuscitate the patient with whole blood will not be successful until bleeding sites are controlled; such measures may even increase bleeding by elevating blood pressure, which reopens vessels that have already stopped bleeding. Attempting to control individual bleeding sites with packing is difficult in a patient with multiple gunshot wounds who is exsanguinating.