Enhancing Venous Outflow in the Lower Limb with Intermittent Pneumatic Compression. A Comparative Haemodynamic Analysis on the Effect of Foot vs. Calf vs. Foot and Calf Compression

Abstract

Objectives: intermittent pneumatic compression (IPC), an established method of deep-vein thrombosis prophylaxis, is also an effective means of leg inflow enhancement, improving the walking capacity and ankle pressure of claudicants, long-term. This study, using duplex ultrasonography, compares the haemodynamic effect of IPC of the (a) foot (at 120 mmHg [IPCfoot/120 mmHg], and 180 mmHg [IPCfoot/180 mmHg]), (b) calf (IPCcalf, 120 mmHg) and (c) both simultaneously (IPCfoot+calf, 120 mmHg), on the venous outflow of 20 legs of normals and 25 legs of claudicants. Results: the peak and mean velocities, volume flow and pulsatility index in the superficial femoral and popliteal veins of both groups increased significantly with all IPC modes (p<0.001). IPCfoot+calfproduced the highest enhancement followed by IPCcalf(p<0.01), which was more effective (p<0.001) than either IPCfoot/180 mmHgor IPCfoot/120 mmHg. The venous volume expelled with IPCcalfand IPCfoot+calfwas 2–2.5 and 3–3.5 times that with IPCfoot/180 mmHgrespectively. Velocity enhancement with IPC was similar between groups and the superficial femoral and popliteal veins. IPCfoot/180 mmHgproduced higher (p<0.01) flow velocities than IPCfoot/120 mmHgin both groups and veins examined; however, differences were limited. Conclusions: all IPC modes proved effective, IPCfoot+calfgenerating the highest venous outflow enhancement. Higher venous volumes expelled with IPCfoot+calfexplain its reported superiority on leg inflow over the other modes. Increase of applied pressure from 120 to 180 mmHg with IPCfootoffered only a small outflow improvement. Venous haemodynamics at rest and with IPC in claudicants do not differ significantly from those in healthy subjects.