[Morphological changes of venous and lymphatic vessels of dog extremities after ligation of major vessels].

Morphological alterations in venous and lymphatic vessels were studied on 38 dogs over time after ligation of the main veins of the hind limb and induction of experimental chronic venous failure. Under these conditions the operated limb developed marked lymphovenous congestion with ectasis and dilatation of blood and lymphatic vessels and capillaries, venous and lymphatic vessels of the limb followed by an increase in the number of the vessels due to high blood content of "reserve" capillaries and small veins in the presence of acute tissue edema. Then the limb developed compensatory-adaptive processes, namely reconstruction of the venous system accompanied by formation of collateral main veins and lymphatic collectors that partially compensated for abnormal venous blood flow. Prolonged impairment of hemocirculation and venous congestion led to anoxia of venous walls, sclerosis, dystrophic, inflammatory and focal sclerotic lesions in the adjacent tissue. This experimental model can be successfully used for solving the problems of the pathogenesis and therapy of chronic venous failure.