Effects of treatment with lower extremity intermittent negative pressure for peripheral artery disease

Abstract

In peripheral artery disease (PAD), arterial blood flow to the extremities is impeded. Exposure of the extremity to cyclic pressure changes increases the macro- and micro circulation. This has recently become a treatment option, as new treatment devices for the application of intermittent negative pressure (INP) to the lower leg have been developed. The overall aim of this thesis was to investigate the physiological and clinical effects of lower extremity INP treatment in patients with PAD. In an experimental study, Hoel et al. showed that application of -40 mmHg INP significantly increased arterial and skin blood flow in the leg, and that -10 mmHg INP not increased blood flow. In a double blind, randomized controlled multicenter trial of 72 patients with intermittent claudication, Hoel et al. showed that treatment with -40 mmHg INP for one hour, twice daily for 12 weeks increased pain free walking distance compared with sham treatment with -10 mmHg INP. For the patients with the most symptomatic disease, treatment with -40 mmHg INP increased both pain free- and maximal walking distance compared with sham treatment. A significant proportion of the patients in the treatment group had a reduction in von Willebrand Factor compared with the sham control group, and the levels of von Willebrand Factor were reduced in the treatment group after 12 weeks, which might indicate a beneficial effect on arterial endothelial activation and endothelial injury. In a follow-up study, Hoel et al. found that the positive effects on walking distance persisted from 12 to 24 weeks of INP treatment. The INP treatment was safe and had few side-effects in patients with PAD.