Disturbances of cutaneous microcirculatory autoregulation in arterial occlusive disease.

Skin blood flux at the dorsum of the foot was measured during local heating--by use of laser Doppler flowmetry--in 6 healthy subjects, 6 claudicants, and 6 patients with rest pain. Significantly different flux increases were noted among the three groups during the first six minutes of heating. Healthy subjects showed an initial rapid increase, followed by an abrupt reduction influx through a probable myogenic autoregulatory microcirculatory control mechanism. In patients the flux increase was slow and continuous, well correlated with the distal perfusion pressure; autoregulatory control was diminished or absent. With less than 100 mmHg perfusion pressure the microvessels are probably constantly dilated through a reduced sympathetic vasoconstriction tone, and further autoregulatory mechanisms are impaired. Measuring of functional behavior of cutaneous microcirculation under low arterial inflow pressure could represent a method for sensitive diagnosis of arterial insufficiency.