A Hybrid Tissue-Engineered Heart Valve

Purpose. This study describes the efforts to develop and test the first hybrid tissue-engineered heart valve whose leaflets are composed of an extra-thin superelastic Nitinol mesh tightly enclosed by uniform tissue layers composed of multiple cell types. Description. The trileaflet Nitinol mesh scaffolds underwent three-dimensional cell culture with smooth muscle and fibroblast/myofibroblast cells enclosing the mesh, which were finally covered by an endothelial cell layer. Evaluation. Quantitative and qualitative assays were performed to analyze the microstructure of the tissues. A tissue composition almost similar to that of natural heart valve leaflets was observed. The function of the valves and their Nitinol scaffolds were tested in a heart flow simulator that confirmed the trileaflet valves open and close robustly under physiologic flow conditions with an effective orifice area of 75%. The tissue-metal attachment of the leaflets once exposed to physiologic flow rates was tested and approved. Conclusions. Our preliminary results indicate that the novel hybrid approach with nondegradable scaffold for engineering heart valves is viable and may address the issues associated with current tissue-engineered valves developed with degradable scaffolds. (C) 2015 by The Society of Thoracic Surgeons