Comparison of Modes of Failure and Clinical Outcomes Between Explanted Porcine and Bovine Pericardial Bioprosthetic Valves.

OBJECTIVE: To compare pathological and hemodynamic modes of failure and operative outcomes between explanted porcine and bovine pericardial bioprosthetic valves.

METHODS: Patients who underwent explantation of their bioprosthetic valves at Toronto General Hospital from 2007-2019 were identified. Retrospective chart review was conducted to attain demographic information, operative outcomes, and echocardiography and pathology reports.

RESULTS: A total of 278 patients underwent explantation of their porcine (n=183) or bovine pericardial (n=95) valves. A greater proportion of the porcine group had severe regurgitation, compared to the bovine group (45.3% vs. 19.8%, p<0.001). Porcine valves had higher rates of cusp flail (19.4% vs. 3.3%, p<0.001). The rates of moderate or worse stenosis were higher among bovine pericardial valves (37.9% vs. 15.8%, p<0.001). On pathologic examination, the porcine valves exhibited more cusp tears (67.6% vs. 50.5%, p=0.006), while higher incidences of calcification were found in the bovine group (p<0.001). Rate of stroke was higher during the explantation procedure of the bovine valves (5.3% vs. 0.5%, p=0.040).

CONCLUSIONS: The primary mode of failure was regurgitation in porcine valves due to cusp tears and stenosis in bovine valves due to calcification. Establishing a clear understanding of failure modes based on valve material may improve design and guide valve selection at the time of surgery.