Effect of Therapeutic Venous Ligation on Blood Flow in Cases of Arterial Occlusion.

Abstract

That the incidence of gangrene in a healthy extremity, whose main arterial supply has been suddenly interrupted, is reduced by the simultaneous or early obstruction of the concomitant or proximal venous return has been demonstrated repeatedly by clinical and experimental observers. The physiological explanation of this phenomenon, however, is in part still the subject of controversy. It is recognized by all recent workers that ligation of the venous return causes an increase in the blood pressure of the affected extremity. Opinions as to its effect upon the flow of blood, however, differ widely. Brooks and Martin believe that this procedure decreases the blood flow, while Holman and Edwards maintain that the blood supply is increased. Neither of these 2 groups of workers measured the flow of blood directly. Recently there has been devised in our laboratory a direct, continuous volume flow apparatus, a modification of the Ludwig stromuhr and of Stolnikow's double inlet-outlet apparatus, which is controlled by an electrically regulated valve. By means of this instrument we have measured directly the changes in blood flow to an extremity, resulting from ligation of its principal peripheral arterial supply and venous return. A preliminary report on this work forms the basis of this paper. Male dogs, weighing 13 to 17 kg. were anesthetized by the intravenous injection of 200 mg. per kg. of sodium barbital. Coagulation was prevented by 30 mg. of heparin per kg. The volume flow apparatus was placed in the right iliac artery, thus measuring the blood which entered the right femoral artery as well as the chief collateral arterial supply to the right leg. The systemic blood pressure was taken from one of the carotid arteries. The right superficial femoral artery and the right common iliac vein were exposed to permit ligation.