Age-related structural changes in cardiac valves: implications for tissue-engineered repairs.

Elderly patients would receive substantial benefits from tissue-engineered heart valves (TEHVs), but most TEHV research has not focused on applications for this growing patient population. There will be numerous technical challenges involved in developing TEHVs for the elderly, such as designing tissues to accommodate higher blood pressure and larger aortic roots that may be friable or calcified. Concomitant medications may also affect the biology of the TEHV. Due to the predominantly senescent behavior of cells from older persons, a nonautologous cell source may be required to develop the TEHV. Decellularized heart valve allografts from elderly donors may not be durable enough to use as a scaffold, but several polymer and natural biodegradable scaffolds may provide promising alternatives. The selection of cell sources, scaffolds, and mechanical/biologic conditioning will need to be precisely targeted to meet the diverse physiological, medical, and surgical requirements of elderly patients.