In vitro pH-controlled calcification of biological heart valve prostheses
✍ Scribed by M. Krings; D. Kanellopoulou; D. Mavrilas; B. Glasmacher
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 202 KB
- Volume
- 37
- Category
- Article
- ISSN
- 0933-5137
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✦ Synopsis
Abstract
Background: Bioprosthetic heart valves still suffer from calcification. In the department of Cryobiology & Biomaterials, we have established an in vitro calcification test method which is suitable for the investigation of calcification patterns of heart valves. In a modified test protocol we use the pH‐dependency of the calcification process to control and stabilise the process by keeping the calcification ions more constant than in the established test protocol. Methods: Five glutaraldehyde‐fixed porcine heart valve bioprostheses underwent accelerated dynamic in vitro calcification individually. Three valves were tested according to the established test protocol. Two valves were studied with the new pH‐controlled loop system. pH drop was used as an index for the consumption of the calcification ions. The degree of calcification was determined by means of μX‐ray (high resolution x‐ray on mammography machine), conventional and micro computer tomography (CT, μ‐CT). Results: We determined the average degree of calcification after 12 million cycles. The value was calculated to be 12 % vs. 67 % (established vs. pH‐controlled group) using μX‐ray (2D), 3 % vs. 16 % using CT, and 3 % vs. 33 % using μ‐CT. Conclusion: A new faster and more potent in vitro calcification method has been developed. Optimisation of this pH‐controlled method in order to implement an additional direct calcification ion concentration control is under construction.