Tissue engineering of cardiovascular structures.

Congenital and acquired diseases of the heart valves and great arteries are leading causes of morbidity and mortality. Current prosthetic or bioprosthetic replacement devices are imperfect and subject patients to one or more ongoing risks including thrombosis, limited durability, increased susceptibility to infection, and need for reoperations due to lack of growth. Tissue engineering (TE) is a new discipline that offers the potential to create replacement structures from autologous cells and biodegradable polymers. Because TE constructs contain living cells, they may have the potential for growth and self-repair and remodeling. Cardiac valve leaflets and large conduit arteries have been made with the TE approach. These TE structures have functioned in the pulmonary circulation of growing lambs for up to 4 months and have demonstrated 1) structural organization to resemble normal valve and artery, 2) satisfactory physiologic function, 3) lack of thrombus formation, and 4) growth.