Experimental evaluation of arterial steal in in vitro models of femoro-tibial bypass with adjuvant arteriovenous shunt.
Arteriovenous shunts are now increasingly used with long femoro-tibial grafts in critical ischaemia of the lower limb. This might result in reduction in blood flow to an already compromised tibial artery, a condition known as arterial 'steal'. In vitro models of the femoro-tibial bypass with adjuvant arteriovenous shunt were investigated in terms of flow rate distribution. Results show that arterial steal will occur at high flow rates through the shunt only when a significant proximal stenosis is present. The degree of steal was independent of the configuration and size of the shunts studied. A simple resistance model was used to predict steal under various flow conditions. The clinical significance of the results is discussed.