The hemodynamics of venous ulceration

Venous ulceration is the result of progressive chronic venous insufficiency, the pathophysiology of which is complex and incompletely understood. Ambulatory venous hypertension in this disease has been well-documented; however, relatively little attention has been directed toward other parameters of venous function. This study evaluates a spectrum of hemodynamic variables and the degree to which they are altered in patients with venous ulceration, and correlates ambulatory venous pressure (AVP) with the noninvasive estimate of this parameter. Air-plethysmography was used to evaluate 36 ulcerated extremities from 30 patients with chronic venous disease and 80 asymptomatic extremities from 54 patients. This technique measures the functional venous volume (VV), assesses valvular function [Venous Filling Index (VFI)], evaluates the efficiency of the calf muscle-pump [Ejection Fraction (EF)], and provides an estimation of ambulatory venous pressure [Residual Volume Fraction (RVF)]. In addition, AVP's were recorded in 13 asymptomatic extremities from 10 patients and 16 ulcerated extremities from 14 patients with chronic venous disease. Significant differences existed between the two groups for all of the hemodynamic parameters. Ulcerated extremities had greater venous volumes, displayed marked deterioration in valvular competence and calf muscle-pump function, and showed significant ambulatory venous hypertension compared to the asymptomatic group. Additionally, the relationship between RVF and AVP appeared linear, with a correlation coefficient of 0.87. Air-plethysmography currently provides the most complete evaluation of venous hemodynamics and should improve our understanding of the pathophysiology of chronic-venous disease.