Skin microcirculatory responses in chronic venous insufficiency: the effect of short-term venous hypertension

The purpose of this study was to examine the effects on the skin microcirculation of a short period of venous hypertension. 34 subjects (17 patients with lipodermatosclerosis and 17 controls) were studied. Laser-Doppler flowmetry was used to assess the hyperaemic responsiveness of the skin following three minutes of ischaemia. This was done by measuring the ratio of peak to basal flow, and the time taken to reach 95% of peak flow. The limb was then subjected to 30 minutes of venous hypertension, following which the hyperaemic responses were repeated. Normal controls demonstrated a significant reduction in hyperaemic response after venous hypertension. Liposclerotic skin had a much less pronounced response to ischaemia which was not significantly affected by 30 minutes of venous hypertension. The clinically normal skin in venous patients showed intermediate values. The results suggest that a short period of venous hypertension causes an immediate deficit in microcirculatory function. This short time scale is consistent with the white cell activation theory of skin damage in venous disease. The loss of vasodilatory capacity by liposclerotic skin may reflect either the constricting effect of pericapillary fibrin cuffs or a fixed degree of capillary occlusion.