Figure 1. Diagram of the shunt preparation.

The iliac artery and iliac vein were connected by a shunt incorporating a screw clip resistance to control mean flow and a variable capacitor to allow independent control of the amplitude of pulsatile flow. A catheter tip pressure manometer was inserted via the inferior mesenteric artery into the abdominal aorta. A pair of piezo electric crystals was used to measure iliac artery diameter at D. An ultrasonic flow probe was used to measure iliac artery flow.