Commissural dehiscence and pannus formation of porcine heart valve bioprostheses.

:  From May 1976 to June 2001, 95 porcine heart valve bioprostheses (BPs) were explanted. Among them, 85 prostheses were available for an analysis of structural valve deterioration (SVD). There were 32 Hancock (H) BPs and 53 Carpentier-Edwards (CE) BPs, with a mean implantation duration of 12 ± 3.5 and 11.0 ± 4 years, respectively. There were two extraordinary complications. One was commissural dehiscence (CD) of the CEBPs in 10/53 cases (18.9%), with a mean duration of 12.7 ± 2.7 years. This was not observed in the HBPs. The other was pannus formation in both BPs. In the mitral position, it was 25/32 (78.1%) in HBPs and 37/53 (69.8%) in CEBPs. In the aortic position, it was 4/32 (1.3%) in the HBPs and 11/53 (20.8%) in the CEBPs. We conclude that CD could not be diagnosed preoperatively and anticoagulation is therefore indicated to prevent pannus formation of such prostheses, particularly in those located in the mitral position.