The physical properties of bovine pericardium: a study of the effects of stretching during chemical treatment in glutaraldehyde.

The uniaxial stress/strain response of bovine pericardium up to a stress of 1 N/mm2 was studied. The tissue was chemically modified in 0.5% buffered glutaraldehyde for 24 hours under various conditions of constraint. Four groups were studied: an unrestricted control group, a group held at their original length, a group stretched to a stress of 0.04 N/mm2, and a group stretched to a stress of 0.4 N/mm2 during treatment. Histological examination revealed changes in structural organization of the collagen, which explained the alterations in the stress/strain response. A significant alteration in mechanical properties after glutaraldehyde treatment was observed, with considerable loss of extensibility for the prestretched tissues. A valve made from such a prestretched tissue may be stenotic and possibly subject to early failure.