Impact of glutaraldehyde on calcification of pericardial bioprosthetic heart valve material.
BACKGROUND
This study was conducted to investigate the impact of the preservation method of bioprosthetic heart valve materials on calcification rates and biocompatibility of the biologic tissue.


METHODS
In subcutaneous rat implants, conventionally preserved bioprosthetic heart valve material was compared with bovine pericardium that was treated with L-glutamic acid to reduce residual glutaraldehyde released from the fixed tissue. Both these methods were compared with bovine pericardium that was stabilized by a dye-mediated photooxidation reaction without glutaraldehyde. Biocompatibility of these biomaterials was tested in vitro using human endothelial cell cultures.


RESULTS
Conventionally preserved bovine pericardium with a high amount of glutaraldehyde incorporated into the tissue resulted in severe calcification 63 days after subcutaneous implantation in rats (165.4 +/- 20 mg Ca2+/g dry weight). Postfixation treatment with L-glutamic acid, which reduces free, unbound aldehyde groups, showed a significant decrease in calcification (89.6 +/- 14 mg Ca2+/g dry weight). Glutaraldehyde-free preservation by dye-mediated photooxidation showed no calcification after 63 days of subcutaneous implantation (1.0 +/- 0.4 mg Ca2+/g dry weight). Regular endothelial cell proliferation was observed on photooxidized and L-glutamic acid-treated tissue, whereas conventionally treated tissue caused endothelial cell death.


CONCLUSIONS
This study underlines the detrimental role of glutaraldehyde in the calcification process of bioprosthetic heart valve materials and emphasizes alternative preservation methods that reduce or avoid the use of glutaraldehyde.
Grabenwöger
M
M
Department of Cardio-Thoracic Surgery, University of Vienna, Austria.
Sider
J
J
Fitzal
F
F
Zelenka
C
C
Windberger
U
U
Grimm
M
M
Moritz
A
A
Böck
P
P
Wolner
E
E
D000818:Animals; D001672:Biocompatible Materials; D001705:Bioprosthesis; D002114:Calcinosis / Q000139:chemically induced / Q000473:pathology*; D002455:Cell Division; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology / Q000648:ultrastructure; D005976:Glutaral / Q000494:pharmacology*; D006350:Heart Valve Prosthesis; D006801:Humans; D066298:In Vitro Techniques; D008297:Male; D010496:Pericardium / Q000187:drug effects* / Q000473:pathology; D010777:Photochemistry; D051381:Rats; D017207:Rats, Sprague-Dawley; D014021:Tissue Preservation / Q000379:methods
D001672:Biocompatible Materials; D005976:Glutaral