Mild external compression of the leg increases muscle blood flow and oxygenation

Abstract

Venous insufficiency is associated with decreases in muscle blood flow (MBF) and oxygenation of the leg. We hypothesize that mild external compression of the leg increases microvascular MBF and oxygenation in a leg experiencing venous hypertension. Thigh compression was used as a model for venous hypertension in five healthy subjects (3 males, 2 females). MBF was measured using photoplethysmography (PPG) and relative muscle oxygenation was measured using near-infrared spectroscopy (NIRS). Both PPG and NIRS probes were placed on the anterior compartment of the leg. An inflatable tourniquet was placed on the thigh and inflated to 65 mmHg. An inflatable cuff covered the entire leg including the probes and was inflated to 40 mmHg. After establishing a baseline, MBF and oxygenation were measured during 12 min of venous occlusion along with a 4-min interval of superimposed leg cuff compression. Baseline of MBF was normalized to 100%; all subsequent data (see table) were divided by this reference value (means ± SE). Baseline muscle oxygenation was established after 6 min of venous occlusion and is reported as ΔmV. In a model of venous hypertension, mild external compression increases leg muscle blood flow and oxygenation. These findings may explain the beneficial effects of compression therapy on healing of venous stasis ulcers.