POSTOCCLUSIVE REACTIVE HYPEREMIA AND POSTURAL VASOCONSTRICTION IN DIFFERENT KINDS OF LEG ULCERS - INVESTIGATIONS WITH LASER-DOPPLER

Laser-Doppler fluxmetry was performed in 42 patients with leg ulcers ( 18 venous, 8 arterial, 12 diabetic-arteriolar and 4 mixed arterio-veno us) and in 9 healthy controls. Using a bipolar probe measurement was c arried out at the ulcer border and on the dorsum of the foot in the su pine and in the sitting position. Reactive hyperemia after three minut e arterial occlusion was produced in both body-positions. In every ulc er-group resting and peak fluxes showed a statistically significant in crease in the ulcer region as compared to normal skin of the lower leg in the control group, the quotient between peak and resting flux (<<r eactive hyperemia index>>) RHI) being significantly lower. The RHI val ues for four ulcer-patients with a dramatic detioration worsening eigh t months later were close to one, while the unchanged and improved cas es showed median values above 1,2. Sitting up was followed by a decrea se of flux in all ulcer-groups as well as in the control group. On the dorsum of the foot there was an increase of the laser Doppler flux in patients with arterial occlusive disease, i.e. in the group with arte rial and mixed ulcers. This study shows that the kind of microcirculat ory flow damage is not different in various causes of ulcerations. The reduced reactive hyperemic response compared to the increased resting fluxes (amount of RHI-decrease) might be a useful predictor for heali ng or non-healing of the ulcer.