Translating autologous heart valve tissue engineering from bench to bed

Tissue engineering is currently being actively investigated in order to ascertain if it can offer an alternative to prosthetic aortic heart valves which may overcome the current limitations of prosthetic aortic heart valves while at the same time conferring the advantages of a living autologous structure, such as biocompatibility, the capacity to grow, repair and remodel. In vitro studies have shown tissue engineered heart valves to have adequate structural and functional properties, indicating a promising future for heart valve tissue engineering. However criteria are required to be able to evaluate autologous heart valves and to deem them satisfactory for clinical use. Pre-clinical animal studies are needed, as a precursor to long term in vivo follow-up studies, in order to establish such criteria. The first challenge is to find appropriate techniques to evaluate the functionality of tissue engineered heart valves in vivo without having to sacrifice the animal. As such, the development of such non-invasive techniques that are able to assess the functionality of tissue engineered heart valves is the next step in translational research. This review discusses methods of evaluating the functionality of autologous heart valves when translating from in vitro to in vivo studies and determines potential assessment criteria imperative to achieve clinical applicability of tissue engineered heart valves in aortic valve replacement.