Two stage EDTA anti-calcification method for bioprosthetic heart valve materials.

Background: The aim of this study was to investigate the effect of two-stageEDTA treatment in diminishing calcific degeneration in bovine pericardial bioprosthetic heart valve material.Material/Methods: Conventionally preserved pericardium specimens were divided into two groups. GroupI (controls, n=18) pieces were first fixed in phosphate-buffered solution (PBS)+0.6% glutaraldehyde at+4 degrees C for 24 hours, then stored in PBS+0.2% glutaraldehyde at room temperature for 6 days. GroupII (study group, n=18) pieces were treated with PBS containing 100 microg/ml ethylenediaminetetraaceticacid (EDTA) at +4 degrees C for 24 hours, then fixed in PBS+0.6% glutaraldehyde as was group I at +4degrees C for 24 hours. After a second exposure to PBS containing 100 microg/ml EDTA at room temperaturefor 24 hours, they were stored in PBS+0.2% glutaraldehyde at room temperature for 4 days. Pericardialpatches were inserted into the dorsal pouches of 18 juvenile male Wistar rats. After 7 weeks of implantation,all the pericardium pieces were harvested from sacrificed rats. The calcium content and biomechanicalproperties of the explanted tissues were evaluated and also examined histopathologically. Results: Thedifference in the calcium content of the control and study groups was statistically significant. Biomechanicaland histopathologic assessment also supported these findings. Conclusions: Application of two-stage EDTAwas found to be useful in the attenuation of calcification in bioprosthetic heart valve materials withmildly increased durability. As calcification was reduced by approximately 50%, it can be consideredfor use with other agents as an adjuvant treatment.

Keywords: Bioprosthesis, Animals, Calcinosis - prevention & control, Calcium - analysis, Cattle, Edetic Acid - pharmacology, Heart Valve Prosthesis, Heart Valve Prosthesis Implantation, Pericardium - ultrastructure, Rats, Tissue Preservation - methods