CALCIFICATION OF BOVINE PERICARDIUM - GLUTARALDEHYDE VERSUS NO-REACT BIOMODIFICATION

Background. Calcific degeneration is the most frequent cause of clinic al dysfunction of glutaraldehyde (GA)-pretreated bioprosthetic heart v alves. The No-React (NR) process has been shown to be a promising anti calcification treatment. In this comparative study, our objective was to delineate the advantages of the NR treatment over GA. Methods. Bovi ne pericardial strips pretreated with GA and NR were individually incu bated in calcium phosphate solution for 21 days at 37 degrees C. The p retreated bovine pericardium then was implanted subcutaneously in rats and retrieved at 14, 21, and 35 days after-implantation. Mineral and morphologic analyses were performed on each specimen. Results. The NR- treated pericardium revealed significantly reduced in vitro calcificat ion compared with the GA-treated tissue (mean tissue calcium content 1 .3 +/- 0.2 versus 5.9 +/- 0.7 mu g/mg; p < 0.001). Mineral analysis sh owed progressive calcification of the GA-pretreated pericardium over t he period of implantation (calcium content increasing from 49.6 +/- 9. 6 mu g/mg after 2 weeks to 134.3 +/- 9.1 mu g/mg at 5 weeks after-impl antation). The NR-treated implants had calcified significantly less (p < 0.05) at each corresponding interval. Moreover, morphologic examina tions demonstrated a protracted inflammatory response in the form of g iant cell and mononuclear cell infiltration associated with intrinsic collagen disruption in the GA-treated tissue; the NR-treated pericardi um maintained morphologic integrity with a mild inflammatory response. Conclusions. The NR biochemical process appears not only to attenuate pericardial calcification, but also to abort the host's destructive i nflammatory response to the xenograft.