Noninvasive testing for the evaluation of chronic venous disease.

Abstract

AbstractNoninvasive tests for chronic venous disease include continuous wave Doppler to assess deep and superficial vein patency and valvular function, strain gauge plethysmography for measurement of venous capacitance and the rate of venous outflow, photoplethysmography to determine venous refilling time (a measure of valvular competence), and duplex scanning, which provides detailed information about the size and location of thrombi and flow patterns in normal and diseased valves. The physiologic information gained with these tests allows more rational treatment and provides insight into the pathophysiology and natural history of varicose veins, postthrombotic limbs, and venous claudication. The crucial distinction between primary and secondary varicose veins is readily made by determining the patency of deep veins with the continuous wave Doppler. Development of late sequelae following deep venous thrombosis (DVT) may be predicted by noninvasive testing. While venous outflow is uniformly decreased following DVT, venous refilling time is abnormally shortened in symptomatic limbs, indicating that postthrombotic sequelae occur in association with valvular incompetence. Further natural history studies with duplex scanning may provide important data on the cause of this valvular incompetence and its time course. Noninvasive testing can also aid in the diagnosis of venous claudication, which is associated with decreased venous outflow.