From cadaver harvested homograft valves to tissue-engineered valve conduits

As cardiac surgery enters its 4th Era, the era of bioengineering, tissue engineering and biotechnology, surgical solutions will embrace living tissue transplants, hybrid structures (inert+living) and biological implants that are really endogenous protein factories. The evolution of conduit surgery from Dacron tubes with pig valves through the wet stored homograft and thence cryopreserved homograft era, is also now entering the tissue-engineered heart valve era. Such constructs will likely resolve many of the lingering issues, which limit the durability and usefulness of heart valved conduits. The saga of this evolution captures in microcosm the revolution that will ultimately result in better treatments for children and adults with structural heart disease. The biological, developmental, and regulatory challenges are described so that an appreciation can be developed for the complexity of this new science and its integration into clinical use. The promise, however, far outweighs the barriers and represents no less than a dramatic new Era in cardiac surgery. (C) 2005 Elsevier Ireland Ltd. All rights reserved.