All procedures involving animal models have been reviewed by the local institutional animal care committee and the JoVE veterinary review board.

1. Surgical technique

1. Perform sterilization of the surgical area using sterile gauze, povidone-iodine and 70% isopropyl alcohol. Drape the pig in the usual sterile fashion. Take a blood sample prior to incision. 
   NOTE: At this point, all equipment, including instruments, balloons, wires, etc. must be sterile.
2. Using an eleven blade or Bovie electrocautery, perform a midline laparotomy to enter the abdominal cavity.
3. Displace the abdominal viscera cephalad to the pig's left to expose the retroperitoneum. Cover the bowel with a moist blue towel to avoid desiccation. Make a sharp incision to enter the retroperitoneum, allowing access to the inferior vena cava (IVC) and infrarenal abdominal aorta.
   NOTE: Identification and protection of the ureters bilaterally is crucial at this portion of the case. Swine retroperitoneal anatomy (including the course of the ureters) grossly mirrors that of humans, with subtle variations detailed below.
4. Circumferentially dissect the aorta from the renal vessels, inferiorly to the aortic trifurcation. Take care to avoid IVC and lumbar artery injury. Once the entire infrarenal aorta is exposed, use calipers to measure the aortic diameter at the mid portion of the infrarenal aorta.
   NOTE: Unlike humans, swine have an aortic trifurcation, not bifurcation.