ALTHOUGH doctors since the time of William Harvey may have had some conception of the pathologic physiology of thrombosis and embolism and although John Hunter,1 in 1794, reported intravascular coagulation occurring during life, it was not until the time of Virchow2 (1845) that arterial embolism was clearly described and until later in the century (1895) that the operation of embolectomy was first attempted by Ssabanejeff3 in Russia. From then until 1911 embolectomy was performed a dozen or more times without success before Labey4 first successfully removed an embolus from the femoral artery. A short time later Key,5 , 6 in Sweden, was . . .