TORN POLYTETRAFLUOROETHYLENE SUTURE USED AS ARTIFICIAL MITRAL CHORDAE TENDINAE:

Background: Although Polytetrafluoroethylene (PTFE) sutures have enough tensile breaking strength as cardiovascular materials, we experienced a torn PTFE suture after mitral valve repair. We hypothesized that intra-operative damage of the PTFE suture caused post-operatively torn-off PTFE suture, which was inappropriately handled during surgery using DeBakey-type forceps with anti-slipping teeth on the jaw face. This experiment was designed to determine how to be damaged of PTFE sutures by DeBakey-type forceps and to measure tensile breaking strength of the damaged sutures. Methods: PTFE sutures (CV-4 size, Gore-Tex) were observed by scanning electron microscope before and after damage by holding and pulling with DeBakey-type forceps. Tensile breaking strength of the damaged PTFE sutures (n = 12), which were partly (30% to 50% of the diameter) torn with DeBakey-type forceps, and non-damaged PTFE sutures (n = 12) were measured. Results: PTFE sutures were not remarkably damaged only by holding with DeBakey-type forceps. Holding, then pulling PTFE sutures with DeBakey-type forceps, however, easily caused completely or partially torn-off sutures. Tensile breaking strength of the partly (30% to 50% of the diameter) torn sutures was significantly decreased than non-damaged (1.36±0.39 vs. 2.43±0.26, p < 0.001). Conclusion: PTFE sutures may be damaged accidentally with DeBakey-type forceps in mitral valve repair. Careful handling of the PTFE sutures should be essential.