SELECTION AND INTERACTION OF BIOMATERIALS USED IN THE CONSTRUCTION OFCARDIAC BIOPROSTHESES

The mechanical behavior of calf pericardium employed in the manufactur e oi cardiac bioprostheses was assessed according to the region from w hich it was selected. For this purpose, selected samples of the tissue were sewn with different types of commercially available sutures and subjected to tensile testing, the results of which were compared with the findings in selected, but not sutured, tissue used as a control. T he results confirm a loss of resistance-that is, a reduction of the ca pacity of sutured samples of the biomaterial to withstand and breakage stress compared with control samples. Taking into account the marked resistance to breakage of the suture thread, this phenomenon can only be explained as a consequence of the deleterious mechanical interactio n between the suture and chemically treated pericardium. This interact ion is illustrated by the shearing force which is responsible for the loss of resistance in the tested samples. These trials demonstrate tha t the results can be improved and the deleterious interaction diminish ed, although not eliminated, when the pericardium is selected from a g iven region. (C) 1998 John Wiley & Sons, Inc.