Background: Polytetrafluoroethylene (PTFE) sutures have been widely used as a mitral chord substitute. We present the cases of 4 patients who underwent mitral valve repair with chordal replacement by PTFE sutures and these required another operation. This gave us the chance to examine the PTFE sutures.
Methods: Structural analysis of the PTFE sutures was performed 26 to 378 days postoperatively. The specimens were examined grossly, microscopically, and by scanning or transmission electron microscopy or both.
Results: The PTFE suture in 1 patient was found to be completely covered with endothelial cells 154 days postoperatively. There was no calcification, and the flexibility and pliability of the PTFE sutures was preserved. Even though the PTFE sutures seemed uncovered on visual inspection, there was a thin lining of collagen and fibrin on the surface. Endothelial cells were seen in areas that looked clear in one specimen 26 days postoperatively.
Conclusions: We think that the new layer of collagen could be promising in terms of durability and that the endothelial layer wil resemble normal tissue in its anticoagulant properties.