A simplified method for the study of thrombus formation on intravascular prostheses

Previous studies demonstrating that fabric-covered, prosthetic heart valves resist thrombus formation, have provoked interest in evaluating the behavior of intravascular metal surfaces, covered with a variety of materials. A simple device for carrying out such studies is described. Struts made from platinum-iridium wire were placed in the atria of 24 dogs. Three struts were uncovered, 12 were covered with porous synthetic fabric, and 9 were covered with everted vein segments. All three uncovered struts rapidly developed thrombus, but both types of covered struts consistently resisted thrombus formation. This study in adult dogs confirms previous findings in growing calves, and suggests a simple technique for the further elucidation of problems associated with thrombus formation on prosthetic heart valves.