HEALING OF MICROVENOUS POLYTETRAFLUOROETHYLENE (PTFE) PROSTHESES IMPLANTED INTO THE RAT FEMORAL VEIN BY MEANS OF 3M PRECISE

Thirty PTFE prostheses (internal diameter, 1.0 mm; length, 5.0 mm; fib ril length, 30 mu m) were implanted into rats' femoral veins by means of a coupling device (3M precise microvascular anastomosis system, 3M, St Paul, MN) and evaluated with electron microscopy at regular interv als from 1 day to 3 weeks after implantation to study, in detail, the healing process. Eighty-three percent of mechanically anastomosed graf ts were found to be patent. At 1 and 3 days after implantation, the wh ole length of PTFE was covered with a clot layer containing platelets and a fibrin network. After 1 week, endothelial-like cells originating from the anastomotic sides grew in across the anastomoses. At 3 weeks , the prostheses were completely covered by an endothelial-like cell l ayer. These results demonstrate that the degree of neo-endothelializat ion in the microvenous PTFE prosthesis anastomosed with 3M rings was n ot delayed, as was seen in the healing of microarterial PTFE tubing th at was mechanically anastomosed.