Pressure dynamics in chronic venous disease

Abstract

Peripheral venous pressure is regulated by central and peripheral mechanisms. Peripheral venous hypertension is an important pathologic component of chronic venous disease and is present in about two-third of patients with chronic venous disease. It can result from reflux, obstructive lesions or high arterial inflow. The dominant influence in patients with peripheral venous hypertension appears to be obstruction rather than reflux. Reflux can be superficial or deep or both. In about 70% of patients with reflux, valvular incompetence is present in the superficial, deep and perforator systems in some combination. In an ex vivo experimental model, conduit pressure increased with smaller native or functional caliber, focal stenosis and increased post-capillary inflow. Venous pressure in the lower limb can be measured in a variety of ways: supine resting pressure, erect resting pressure and ambulatory venous pressure. These measurements are affected by factors such as intra-abdominal pressure, intra-thoracic pressure, gravity, venoarteriolar reflux, valve reflux and venous obstruction. Venous obstruction is associated with elevated supine pressures while reflux is associated with elevated erect resting and ambulatory venous pressures. Ambulatory venous pressure reflects venous hypertension in patients with advanced venous disease. However, our investigation has shown that ambulatory venous pressure hypertension is rarely present if air plethysmography testing is negative. Consideration maybe given to the omission of the ambulatory venous pressure testing if air plethysmography testing is normal.