USE OF THE 3M PRECISE MICROVASCULAR ANASTOMOTIC SYSTEM IN GRAFTING 1-MM DIAMETER ARTERIES WITH POLYTETRAFLUOROETHYLENE PROSTHESES - A LONG-TERM STUDY

The 3M Precise Microvascular Anastomotic System has had an experimental long-term testing for the first time in polytetrafluoroethylene (PTFE) 1-mm diameter arterial grafts. The grafts were placed in the infrarenal aorta of 48 rats. At different time intervals (2 weeks, 16 weeks and 1 year), each section containing a graft and its pair of anastomotic devices was removed and processed for light and scanning electron microscopy, with the aid of a newly-designed device. Eighty-three percent of the mechanically anastomosed grafts were found to be patent. Only 14.8 percent of the grafts harvested at 16 weeks or 1 year showed neo-endothelial lining on the inner surface of the graft. A constant finding of this study was the marked atrophy of the aortic media within the devices, that was progressively evident from 2 weeks to 1 year. A network of capillaries within the graft walls was present at 16 weeks. In one case, a large capillary was found to traverse the graft wall and to reach the luminal surface, suggesting that transmural capillaries may contribute to the formation of neo-intima in 1-mm PTFE grafts.