Current Role of Air Plethysmography in Arterial and Venous Disease Management

Abstract

Air plethysmography (APG) is a technique that allows the mea surment of limb volume changes with different maneuvers. The device consists of a cuff that is placed around the leg, a calibratable pressure transducer, and an analog chart recorder that provides a visual display. Parameters derived from performing various APG measurments with positional changes include the venous filling index, which quantitates venous reflux, the ejection fraction, which correlates with calf muscle pump function, and the residual volume frac tion, which correlates with ambulatory calf venous pressure. Venous occlusion techniques allow the measurment of arterial flow into the limb and the venous outflow fraction, which can be used to evaluate venous obstruction. Differenti ation of pathology in the deep venous system from that in the superficial venous system is possible. APG has been validated in the evaluation of venous insuf ficiency in the legs and has a place in the evaluation of symptomatic patients suspected of having deep venous thrombosis. The ability of the device to quan titate absolute arterial flow to the lower extremity makes it useful in evaluating operative results and following disease progression.