Antimineralization treatments in stentless porcine bioprostheses: An experimental study

Background and aim of the study: Photo-oxidation treatment of porcine stent less bioprostheses (Photofix) was compared with glutaraldehyde fixation, wi th either AOA (Freestyle valve) or Tween-80 (Edwards Prima Plus valve). Methods: Six valves of each type were implanted in juvenile sheep, in the p ulmonary position. Valves were explanted after three or six months and exam ined macroscopically, by X-radiography, and by light and transmission elect ron microscopy. Calcium content was determined by atomic absorption spectro metry. Results: The cusps of all valves were free of calcification, and had normal histology and function. Calcium contents (median +/- IQR) were 0.63 +/- 0. 45, 0.73 +/- 1.46 and 0.46 +/- 1.42 pg/mg for the Photofix, Freestyle and P rima Plus valves, respectively (p = NS). Calcium contents of the aortic wal l portions were 0.71 +/- 1.27 (Photofix), 10.78 +/- 77.22 (Freestyle) and 2 8.70 +/- 66.53 (Prima Plus) (p <0.05 for Photofix versus Freestyle or Prima Plus). Conclusion: Photo-oxidation of a porcine stentless valve prevents calcifica tion not only in the cusps, but also in the aortic wall portion.