Mode of failure of the Hancock pericardial valve xenograft

Bioprostheses made of bovine pericardium became popular as cardiac valve substitutes mainly because they had superior hemodynamic performance compared with porcine bioprostheses.1,2 However, after a period of initial enthusiasm, reports showed that some of these devices are not free of complications.3\u20137 We8 have observed similar results at medium-term follow-up in patients with the Hancock pericardial xenograft. We now describe the pathologic substrates of failure of such device