[The third venous system of the lower extremity and its clinical significance].

In deep venous thrombotic and aplasia cases superficial veins become dilated. With the resulting incompetence of the valves, venous blood stream is not directed to the heart, but to the ankle as well. In these cases the superficial system does not support the venous drainage of the limb, but gives a further load. The question is if one can ameliorate the venous drainage with removal of insufficient varicose veins, or does it make the outcome worse? A new examination was developed to determine if collateral veins in the subfascial space are enough to drain the venous blood of the limb. A tensiometer cuff was placed on the limb and inflated. The patient was asked to walk, if it was performed without complaints then the results was negative and the superficial veins were removed. In these cases no venous disturbances were detected during the operation or following that, in spite of the absence of deep venous circulation and radical removal of varicose venous bed. It means, that in the absence of deep venous circulation develops a collateral circulation not only in the subcutaneous, but in the subfascial space as well and it can alone maintain the venous drainage of the limb, this is the third venous system of the leg.