VENOARTERIOLAR RESPONSE TO EXPERIMENTAL VENOUS HYPERTENSION IN LEGS WITH CHRONIC VENOUS INSUFFICIENCY AND IN HEALTHY LEGS, MEASURED USING ADOUBLE-WAVELENGTH LASER-DOPPLER TECHNIQUE

The venoarteriolar response (VAR) of the skin in legs caused by experi mental venous hypertension was measured using a new, double-wavelength laser Doppler probe technique (543 nm and 780 nm). This enables the m easurement of the laser Doppler flux in the superficial and deep layer s of the skin simultaneously. The recordings were obtained from the le g with the patient in a recumbent position with a sphygmomanometer cuf f around the thigh. The VAR was recorded at the cuff pressures of 30 m mHg and 60 mmHg. Ten patients with chronic venous insufficiency (CVI) and 20 control subjects with healthy legs were investigated. The VAR i ncreased in relation to the increase of cuff pressure at both waveleng ths. There were no significant differences in the VAR between the cuff pressures within or between the legs with CVI and healthy legs. The V AR measured at 780 nm was very significantly greater than the VAR meas ured at 543 nm in legs with CVI (p<0.005), as well as in healthy legs (p<0.001). The VAR depends both on the wavelength of the laser Doppler light used-and on the degree of venous hypertension. The VAR is not i mpaired in legs with CVI compared with healthy legs.