Lower limb deep venous flow in patients with peripheral vascular disease

A prospective controlled study was undertaken to determine how peripheral vascular disease (PVD) influences flow in the deep veins of the leg.

Eighty-nine patients with peripheral vascular disease and 35 age-matched control subjects were studied. The popliteal vein diameter and flow velocity were measured at rest by means of color duplex ultrasound scanning, and these measurements were compared with the ankle-brachial pressure index. For 23 subjects, measurements were also performed during reactive hyperemia and then repeated after venous return from the foot was prevented by an ankle cuff.

There was a significant correlation between the ankle-brachial pressure index and the popliteal vein diameter (r = 0.35, P <.001) but a negative correlation between the ankle-brachial pressure index and venous flow velocity among patients with PVD (r = -0.24, P =.002). In PVD patients the diameter decreased further in reactive hyperemia, whereas it increased in control subjects ( P <.001). Preventing venous return from the foot in PVD patients led to diameter increase at rest and abolished the reduction in diameter caused by reactive hyperemia. Despite the reduction in diameter during reactive hyperemia, flow velocity increased less in patients with PVD than it did in control subjects (P =.01).

Chronic tissue ischemia results in constriction of the popliteal vein. This appears to be an active process related to the washout of humoral factors from ischemic tissues distally, which leads to an increase in flow velocity. The latter may confer some protection against the deep vein thrombosis that would otherwise tend to occur with low venous flow rates.