Abstract 11955: Development of in vivo, Tissue-Engineered, Autologous, 3D Heart Valvular Tissue, Type SC Biovalve With Excellent Mechanical Properties, Valular Functions, and in vivo Performances
Background: Autologous pericardium is widely used for the reconstruction of intracardiac structures and pulmonary artery, and for aortic valve leaflets after fixation with glutaraldehyde for mechanical strengthening. We developed autologous prosthetic tissues by using in-body tissue architecture (IBTA) technology, which is a novel and practical approach of regenerative medicine based on the tissue encapsulation phenomenon of foreign materials in living bodies. In this study, IBTA-based heart valves with robust tissue wall [Biovalve (BV) Type SC] were prepared by using a novel caged mold. The mechanical properties of the valves were compared with human pericardium, and in vivo durability was evaluated in animal implantation study after in vitro evaluation using a pulsatile circulation circuit.
Methods and Results: The BV preparation molds could be produced rapidly by using a 3D printing machine, based on the designed 3D-shape and size of native heart valves regardless of their type. Upon 1- or 2-month goat subcutaneous embedding of the molds aortic or pulmonary valve-shaped BVs (diameter 5-30 mm) were formed as type SC from completely autologous connective tissue with collagen and fibroblasts. All surfaces of the BVs that were in contact with blood were highly smooth and flat. The three leaflet tissues were seamlessly connected with the surrounding conduit tissue, and showed homogeneous wall thickness and excellent mechanical strength that was equivalent to or more than that of the human pericardium, with individual or regional differences. As an aortic valve, in vitro evaluation of the BV showed excellent valvular functions (regurgitation ratio 5.7% at 70 beats per minute). In a goat model, postoperative echocardiography after surgical replacement of the biovalves with stents showed smooth movement of the leaflets with little regurgitation under systemic circulation. In all implantation studies, the luminal surface after implantation was very smooth and fully covered with thin neointima, including endothelial cells without thrombus formation.
Conclusion: Functional, completely autologous, robust, 3D aortic or pulmonary BVs showing the potential for clinical application were developed by in-body embedding of specially designed molds.
Author Disclosures: Y. Nakayama: None. Y. Takewa: None. T. Moriwaki: None. H. Sumikura: None. S. Miyamoto: None. K. Okamoto: None. M. Funayama: None. M. Furukoshi: None. E. Tatsumi: None.
- © 2015 by American Heart Association, Inc.