Abstract
An expanded polytetrafluoroethylene (PTFE) graft can be made stretchable by elastomer coating with longitudinal compression. Using polyurethane as the elastomer, we produced elastomer end-coated stretch PTFE grafts (elastomer PTFE grafts) and implanted them in twelve female adult mongrel dogs to assess handling characteristics and healing. Each dog had bilateral aortoiliac grafts placed, one a standard PTFE and the other an elastomer PTFE graft. The grafts were 7-Scm in length and 6mm in diameter. The elastomer PTFE grafts showed superior longitudinal elasticity, retention of shape, no graft tearing with suture tension and no needle hole bleeding. The grafts were harvested at intervals to 120 days postoperatively. Satyisfactory patency was obtained with both standard (8/10) and elastomer PTFE grafts (9/10) at 90-120 days. No significant difference in the thichness of intima and the length of pannus ingrowth wes noted between the standard and elastomer PTFE grafts. Complete separation from the surrounding tissue because of no outer tissue incorporation was seen at the elastomer treated graft segments as opposed to the well incorporated untreated segments. In conclusion, the elastomer PTFE graft provided excellent handling characteristics without detracting from patency; however, the lack of outer tissue incorporation may be a potential disadvantage in its clinical use.
