Microcirculation disturbances in different stages of chronic venous insufficiency

Abstract

Summary Objectives: The aim of this study was to investigate patients with different clinical stages of chronic venous insufficiency (CVI) by laser Doppler fluxmetry (LDF) in order to asses whether these clinical entities correspond to specific flow regulation. Methods: 3 groups of subjects were incorporated in the study. Microcirculation investigations were carried out at rest and after hemodynamics tests. Changes in the laser Doppler flux minus the biological zero value were measured after 3 minutes of arterial occlusion and by experimental venous hypertension (40 and 70 mmHg) and expressed relatively to the pretest resting value. Results: Resting LDF was significantly higher in patients with CVI II and CVI III stage as compared to the both groups with healthy subjects and the group with CVI I stage (p <0.001). In patients with CVI II and CVI III stage LDF remained nearly unchanged after arterial occlusion (6% increase vs. 342% in healthy subjects and 214% increase in patients with CVI I (p <0.001 vs. p <0.001). Experimental venous hypertension (cuff pressure 70 mmHg) led to profound reduction of flux in all 3 groups (I: –90%; II: –91.7%; III: –91.4%). At the same time, absolute LDF values during experimental venous hypertension (40 and 70 mmHg) were significantly higher in patients with CVI II and III in comparison to patients with CVI I and healthy subjects (p <0.001 vs. p <0.001). Conclusion: It seems that in severe CVI patients the venoarteriolar reflex, despite being comparable in magnitude to that in healthy subjects, may nonetheless be insufficient to reduce LDF during experimental venous hypertension to the level similar to that in healthy subjects and patients with CVI I.