Prevention of thrombosis of central venous catheters.

: All central venous catheters develop a fibrin sheath and clot formation which can cause pulmonary emboli, especially when the catheter is withdrawn. The degree of fibrin sheath and clot is dependent not on the length of residence in the vein but related more to the type of catheter material. A study was performed placing the more commonly used catheters in arteries and veins of canines for two weeks and then evaluating the volume of sheath and thrombus. Polyurethane catheters were the most thrombogenic, whereas polyurethane coated with hydromer was the least thrombogenic, followed closely by silicone catheters. Polyvinyl chloride catheters were intermediate in their thrombogenic activity.