| Abstract: | In twenty-five acute canine experiments polyvinyl chloride (PVC) tubes, both uncoated and coated with tridodecylmethylammonium chloride/heparin (TDMAC/heparin) complex, were tested in thoracic aortic bypass lasting five hours and in inferior vena caval bypass lasting thirty minutes. In aortic bypass, heparin-coated tubes were almost totally nonthrombogenic in contrast to uncoated tubes which had definite thrombus formation. Smoothly tapered tubes were significantly less thrombogenic than were hybrid tubes with junctions. Tube design, especially junction-free construction, was more important than heparin coating in preventing thrombus formation. In vena caval bypass heparin-coated tubes were totally nonthrombogenic in contrast to uncoated tubes which did show thrombus formation and thrombo-embolism. The smoothly tapered TDMAC/heparin-coated shunt tubes were successfully employed in four patients during thoracic aortic aneurysmal resection. |
