Microcirculatory changes parallel the clinical deterioration of chronic venous insufficiency

Objective: This study was designed to determine microcirculatory changes in patients belonging to different chronic venous insufficiency (CVI) classes. Methods: A total of 80 patients from all CVI classes and 15 symptom-free volunteers were studied prospectively. Venous reflux was verified with duplex scanning. Patients with conditions that may have affected the local microcirculation were excluded. Skin blood flux (SBF) was measured using a laser Doppler flowmeter in the supine position in a constant room temperature of 22°C and after 10 minutes acclimatization. The veno-arteriolar response (VAR) was estimated from the SBF change from supine to dependent position. The vasomotor activity (VMA) was determined from the baseline SBF. The amplitude of cycles (AC) and SBF during heat stress at 45°C were also measured. Results: Mean age, duration of disease and prevalence of deep vein thrombosis were greater in classes 4-6 compared with classes 1-3 (P<0.02). Although there was an increase in SBF and AC in classes 2 and 3 compared with the controls this was not significant. Values for SBF and AC were higher in classes 4-6 than classes 1-3 (P<0.01), and higher in class 6 than class 4 (P<0.01). Upon heating, the SBF increased more in classes 1-3 than in classes 4-6 (P<0.01), and in class 4 more than in class 6 (P<0.01). Values for VAR and VMA decreased with worsening of CVI, but these changes were not significant. Conclusions: Deterioration of the microcirculation is largely responsible for the clinical symptoms and signs seen in patients with CVI classes 4-6.