Long-term Evaluation of a Novel Tissue-engineered Heart Valve Without Any Foreign Bodies
Yoshiaki Takewa1, Yasuhide Nakayama2, Junichi Shimamura1, Nobumasa Katagiri1, Eisuke Tatsumi1.
1National Cerebral and Cardiovascular Center, Osaka, Japan, 2Biotube Inc., Tokyo, Japan.
OBJECTIVE: We are developing a novel autologous tissue-engineered heart valve (Biovalve) with a unique in-body tissue engineering. This is expected to be a viable bioprosthesis keeping better biocompatibility. In this study, we developed a conduit-type valve without any foreign bodies and tested the feasibility and long-term availability in large animal experiments.
METHODS: We created plastic molds for Biovalves with 3D printer easily and quickly considering the recipient character. We embedded them in the subcutaneous spaces of adult goats about 2 months. After extracting the molds with the tissue en-block and removing the plastic molds only, Biovalve with tri-leaflets similar to those of the native valves were constituted from completely autologous connective tissues and fibroblasts. Total 20 conduit-type Biovalves were implanted in the apico-aortic bypass or the pulmonary artery of goats, (8 and 12, respectively). No anticoagurants were used after implantation.
RESULTS: Biovalves were successfully implanted and showed smooth movement of the leaflets with a little regurgitation in angiogram, and the maximum duration reached to 3 years 4 months. Histological examination of the Biovalves showed the autologous cells covering the laminar surface of the valve leaflets as the endothelium and also getting inside to construct characteristic tissues like native leaflets.
CONCLUSIONS: The Biovalves have a potential to be used for viable bioprosthetic valves and to keep better function and biocompatibility longer than current ones.
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