[The mechanisms of critical impairments of microcirculation in patients with chronic ischemia of lower extremities].

The interrelationships of the arterial inflow, venous return and state of microcirculation were studied in 115 patients with different degrees of chronic ischemia of the lower extremities due to obliterating diseases of the arteries using ultrasonic dopplerography, photoplethysmography, percutaneous determination of the partial oxygen pressure. It was found that the main adaptive mechanism of compensation of the deficient arterial inflow was compensatory angiotrophoneurosis, slowing down of blood flow in the microcirculation bed due to a spasm of the venule precapillary sphincter. The threshold levels of critical impairments of the macro- and microdynamics were established which allowed prognosis of the development of critical ischemia of lower extremities.