Effect of ethanol and ether in the prevention of calcification of bioprostheses

Background. Lipids play a significant role in the process of calcification of bioprostheses. We assessed whether lipid extraction by ethanol, ether, o r a surfactant could mitigate calcification of glutaraldehyde-treated biopr ostheses. Methods. On 200 bovine pericardium samples pretreated with 0.6% glutaraldeh yde, lipid extraction was carried out by ethanol, ether, or the tween 80 su rfactant, and combinations thereof. The treated tissues were implanted subc utaneously in 50 juvenile rats for 4 and 6 months. Lipids were analyzed by Fourier transform infrared spectrophotometer and chromatography before impl antation. Calcium content of implanted tissues was assessed by atomic absor ption spectrometer. Results. Ethanol, ether, or surfactant did mitigate calcification. The most efficient pretreatments were the combination of ethanol and surfactant (ca lcium content: 15.5 +/- 6.8 mug/mg dry tissue after 6 months implantation) or the combination of ethanol, ether, and surfactant (13.1 +/- 6.2 mug/mg d ry tissue) when compared with surfactant alone (42.9 +/- 12.7 mug/mg dry ti ssue). Conclusions. Ethanol or the combination of ethanol and ether added to the c urrently used glutaraldehyde-surfactant treatment further mitigates calcifi cation. (C) 2001 by The Society of Thoracic Surgeons.