Influence of healing on the disturbed blood flow regulation in venous ulcers

Cutaneous blood flow regulation is disturbed in severe chronic venous insufficiency (CVI). The feedback system between the transmural pressure in the postcapillary venules and the precapillary resistance regulating arterioles has gone awry. The upregulated control system causes "luxus"-hyperperfusion. In this study laser Doppler fluxmetry was performed in 6 patients' florid venous ulcers (U) and later in the former ulcer area after healing (H) and in the inner ankle area of 12 healthy volunteers (C). Laser Doppler flux (LDF) changes were measured with the leg elevated and lowered as well as after arterial and during venous occlusion. The results proved a diminished (p < 0.01) flux increase with the leg elevated (U: LDF = -9%, H: LDF = 3.1%, C: LDF = 80%) and after arterial occlusion (U: LDF = 1.3%, H: LDF = 0%; C: 189.6%) in severe CVI both in florid ulcers and after healing. The ability to reduce flux when transmural pressures were increased remained. Leg lowering reduced flux by 46.4% in ulcers and by 36.8% after healing. This postural response to high transmural pressures, however, seemed weakened compared to controls, where LDF decreased by 65.8%. Our findings suggest that the postural feedback system remains disturbed and upregulated even after a venous ulcer has healed.