ELASTIC BEHAVIOR OF SUTURED CALF PERICARDIUM - INFLUENCE OF THE SUTURE THREADS

The purpose of this study was to assess the elastic behaviour of calf pericardium used in the construction of cardiac bioprosthesis valve le aflets, sutured with different types of commercially available sutures : silk, Gore-Tex, Surgilene and nylon. Thirty-two samples (four series of eight samples each) were subjected to tensile strength testing to breakage. The breaking stress (MPa) ranged between 4.89 MPa for sample s sutured with Gore-Tex and 5.22 MPa for those sewn with nylon. Three samples from each series were subjected to a stepwise stress test, inv olving increasing levels of stress followed by return to zero, to defi ne the elastic limit (the cut-off point beyond which strain is no long er reversible). Analysis of the results provided the mathematical func tions that govern the elastic behaviour (stress/strain) within the ela stic range for each type of sutured sample. The series sutured with Su rgilene presented the highest mean value (1.649 MPa). Finally, a stati stical study was carried out to determine which series showed the grea test probability of having the least interaction between the thread an d the pericardium. Allowing an interval of +/-10%, Gore-Tex showed the best probability in this respect. However, real fatigue testing is ne cessary to definitively determine which is the best suture to use. (C) 1996 Elsevier Science Limited