Prevention of calcification of bioprosthetic heart valve cusp and aortic wall with ethanol and aluminum chloride

Background. Calcification is frequently associated with device failure of bioprostheses fabricated from either glutaraldehyde pretreated porcine aortic valves or bovine pericardium. It was hypothesized that differential pretreatment with ethanol-aluminum chloride will prove safe and efficacious for inhibiting the calcification of both the porcine aortic valve bioprosthetic cusp and the aortic wall. Methods. Glutaraldehyde-fixed porcine aortic valves were subjected to differential aluminum chloride (AlCl3) and ethanol pretreatment; aortic wall segments were treated exclusively with AlCl3 (0.1 moles/L) for 45 minutes, 6 hours, or 8 hours (groups 3A, B, and C, respectively), followed by valve cusp incubations in ethanol (80%, pH 7.4). Nontreated control bioprosthetic valves were either stent-mounted porcine aortic valve bioprostheses (Carpentier-Edwards, group 1) (Edwards, Santa Anna, CA) or St. Jude Toronto SPV valves (St. Jude Medical, St. Paul, MN) (group 2). Mitral valve replacements were carried out in juvenile sheep for 150 days. Results. Calcium in cusps from group 3A was 2.84 +/- 0.62 mg calcium/g tissue versus control, 22.79 +/- 8.46 mg calcium/g tissue, p = 0.04. Valves pretreated with AlCl3 for 45 minutes, 6 hours, and 8 hours had significantly lower levels of calcium in the aortic wall compared to controls (40.38 +/- 5.66, 26.77 +/- 4.02, and 28.94 +/- 8.25 mg calcium/g tissue for groups 3A, 313, and 3C, respectively, vs 95.47 +/- 17.14 mg calcium/g tissue for group 1, p < 0.001, and 133.42 3.96 mg calciurnIg tissue for group 2, P < 0.001). Conclusions. Differentially applied ethanol and aluminum chloride pretreatment significantly inhibited calcification of both the glutaraldehyde-fixed porcine aortic valve bioprosthetic cusp and the aortic wall.