The prevention of intravascular thrombosis based upon electric properties.

Although many theories have been reported as to the cause of venous thrombus, the three factors listed and explained by Virchow a re still widely accepted. Various experimental studies have been done based upon the assumption that the disturbance in blood vessel intima was the main causing factor for the formation of thrombus due to mechanical or chemical injuries to the intima. A report wa'l made by Abramson in 1927 as to the negative charge nature of the surface of blood ce lls, and later in 1953, Sawyer et al., reported that the intima of blood vessEls was negatively charged in the physiological condition, and that thrombus was not caused by the electric repulsion of the blood cells and the intima. Furthermore, it was said that when the intima was mechanically or chemica lly injured, the negative charge of the intima underwent reversion of polarity, and the thrombus formed. This investigation was carried out in vitro by using autoradiography to deter· mine the necessary intensity of electricity, duration of electrification, and other factors which were required for the formation of thrombus by positive charge under normal condition. At the same time, to test the effect of thrombus prevention, experiments using negative charge were conducted in which the intima was mechanically injured to easily make thrombus. And, after applying electrification, the intimal surface of the blood vessel was observed microscopically. Negative charge was applied to the transplantation of a rtificial blood vessel for vein. Wrinkled teflon graft about 3 em in length was transplanted to the inferior vena cava of an adult dog. A platinum electrode was coiled around the part of end to end anastomosis and electrified as a negative electrode. After a certain period of time, patency was examined by venography. Patent cases were all of very early stage of electrification, and no thrombus formation occurred with a case of negative electrode of platinum coil used to prevent kinking and pressing.