[Microvascular consequences of low distal blood perfusion rates]

It is classical, in obstructive arterial disease, to be most concerned with the truncal arteries, although nutrition and exchanges occur at the level of the terminal vessels. The most important events occur in the muscles and in the skin, at the extremity of the limb and one wonders whether "ischaemic disease" could perhaps be summarized as the result of low perfusion rates. The laws of hydraulics are unusual in this situation, the microcirculation is autonomous and autoregulated. The architectonics are also unusual: the distribution into asymmetrical parallel networks explains the heterogeneity of the distribution in which stasis, conglutination and red cell rigidity, interstitial flooding and the rheological consequences play a major though unequal role in the skin and the muscle. The problems of the haematocrit, viscosity, surface tension or interface and the electrostatic potentials are more important at this level and they determine the therapeutic decisions.