Assessment of Lower Extremity Venous Valvular Insufficiency Examinations

Abstract

Usually, venous insufficiency affecting an extremity results from elevated pressure, whereas arterial insufficiency usually is caused by reduced pressure energy. Except when caused by arteriovenous fistulae, elevated venous pressures are caused by obstruction to outflow and/or by incompetence of the venous valves, particularly at popliteal level and in the calf perforator veins. In the lower extremity, such elevated venous pressures can result in chronic changes that cause symptoms and/or signs that range from “tired legs” to ulceration. Although mild venous hypertension may constitute only a relative inconvenience such as varicose veins, more severe cases can lead to debilitating ulceration that may demand a change in lifestyle. Assessing an extremity for venous valvular insufficiency means detecting venous reflux. This work describes the plethysmographic, continuous-wave Doppler, and duplex ultrasound imaging modalities that can be used for detecting venous reflux in the deep, superficial, and perforating veins. Although plethysmographic and continuous-wave Doppler modalities have been supplanted largely by duplex ultrasound imaging, they have been included for completeness because they can continue to fulfill a role in overall functional assessment. Whatever the testing modality used to assess venous reflux, it is essential to verify the patency of the deep veins before any intervention in the superficial venous system.