PATHOLOGICAL ASPECTS OF POLYTETRAFLUOROETHYLENE SUTURES IN HUMAN HEART

Background. Polytetrafluoroethylene (PTFE) sutures have been widely us ed as a mitral chord substitute. We present the cases of 4 patients wh o underwent mitral valve repair with chordal replacement by PTFE sutur es and these required another operation. This gave us the chance to ex amine the PTFE sutures. Methods. Structural analysis of the PTFE sutur es was performed 26 to 378 days postoperatively. The specimens were ex amined grossly, microscopically, and by scanning or transmission elect ron microscopy or both. Results. The PTFE suture in 1 patient was foun d to be completely covered with endothelial cells 154 days postoperati vely. There was no calcification, and the flexibility and pliability o f the PTFE sutures was preserved. Even though the PTFE sutures seemed uncovered on visual inspection, there was a thin lining of collagen an d fibrin on the surface. Endothelial cells were seen in areas that loo ked clear in one specimen 26 days postoperatively. Conclusions. We thi nk that the new layer of collagen could be promising in terms of durab ility and that the endothelial layer will resemble normal tissue in it s anticoagulant properties.