The polydimethylesiloxe which is one compoment of the ordinary silicone rubber is known to have better blood compatibility than the rubber itself. Noticing this fact, we made silica free silicone tube (SFS) by coating pure polydimethylesiloxe on the inner surface of medical graded silicone (MGS) tube with a new technique and tested its blood compatibility by implanting the tube in the arterivenous shunt in dogs.
The patent period was monitered by the temperature change on the tubes detected with a thirmistor circuit. The average patent period of 5 SFS tubes was 15 days which was about 4 times longer than those of ordinary MGS tubes simultaneously tested.
