[The external saphenous vein and the Doppler effect]

After medium physical exertion, twelve athletes had their venous reflux measured using a Doppler fluxometer. A rise in the speed of the blood flow was recorded. This is due to the hyperactivity of the thoraco-abdominal and cardiac pumps, whose efficiency is boosted by arteriocapillary vasodilation. In some cases, this happens only in the deep system. But in others, this "arterialization" is apparent in the superficial system too, and especially in the region of the short saphenous vein. This occurs in such a way as to suggest that the deep course becomes saturated and so the reflux is redirected along the superficial course. This hypothesis is an argument in favour of the existence of vein to vein anastomosis.