Development of a growable vascular graft.

ABSTRACT

A vascular graft that can grow with the growth of its recipient was developed. The graft implanted in the thoracic descending aorta grew slowly to the expected size within a year after implantation in puppies. Human saphenous vein was used as the substrate material. It was dipped into distilled water and sonicated, resulting in cell destruction, and followed by cross-linking with a polyepoxy compound to give both controlled biodegradability, hydrophilicity, and antithrombogenic properties. Four millimeter inner diameter (ID) grafts, enveloped with polyester mesh tubes of 10 mm ID, were implanted in 11 puppies. The diameter of the grafts grew to 9.5 mm from their original 4 mm. After 1 year, the graft walls that were reinforced with polyester mesh were covered with endothelial cells. The following requirements were provided in a growable graft 1) antithrombogenicity in a small caliber graft; 2) ability to grow as well as to terminate growth. The polyester mesh tube, which was larger than the graft, caused arrest of growth at the expected diameter, whereas the growth rate was controlled by the degree of graft cross-linking. With this method, any size graft can be made by changing the size of the original graft and the polyester mesh tube around it.