Development of a heat-melting method for stent graft suturing

支架移植存在几个亟待解决的问题。其中之一是缝合结扎后的磨损问题。可膨胀的金属线通过缝合线固定，织物通过缝合线嫁接，缝合线由聚酯纤维等聚合物材料制成。由于聚合物材料通常很滑，需要三次以上的结扎才能防止结子松动，从而导致体积增大。通常，细长的支架移植物不需要笨重的结节。为了解决这一问题，我们开发了一种由普通涤纶纤维涂覆特殊聚合物制成的混合缝合线，该缝合线的熔点在180~220摄氏度左右，而普通涤纶纤维在260摄氏度熔化。使用我们的特殊缝线，当移植物在220摄氏度加热时，被测试的支架移植物的结扎部位的所有结都被聚合物熔化固定。因此，支架移植物加热220摄氏度后，磨损问题就完全解决了。

Stent grafts have several problems which should be solved urgently. One of them is a fraying problem after suture ligation. Expandable metal wires are fixed by sutures with fabric grafts by sutures, which are made of polymer materials such as polyester fibers. As polymer materials are usually slippery, more than three-time ligations are required to prevent the knots become loose, which resulted in bulky. Generally bulky knots are not desirable for slim stent grafts. In order to solve the problem, we have developed a hybrid suture made of regular polyester fibers coated with special polymer having a lower melting point, around 180~220 Celsius,while regular polyester fibers melts at 260 Celsius. Using our special sutures, all the knots of ligated sites of the tested stent graft were fixed by meltdown of the polymer when the graft was heated at 220 Celsius. Consequently, the fraying problem is completely overcome after 220 Celsius heating of stent grafts.