|
Introduction: Heart valve tissue engineering has been presented as a “promising” solution” for over 20 years. These living devices are supposed to have the capacity to grow, heal and repair or remodel. This would avoid structural valve degeneration of currently used biological heart valve prostheses or the need for life-long anticoagulation or mechanical devices. Especially for patients with stenotic aortic valve disease, which is the third most common cardiovascular condition in Western societies, this solution might be useful.
Methods: A literature search has been performed for the years 2010-2014 with focus for results of tissue engineered valves of in-vitro, in-vivo animal and patient studies
Results: Most experiments were still in-vitro. Especially those experiments which focus on synthetic biodegradable scaffolds have not left the laboratory, because these cannot withstand systemic pressures. The animal studies involved scaffolds of biologic origin with or without reseeding with cells. Cells were harvested from vascular, embryonal tissues or from bone marrow. Large animal studies (ovine, porcine) dealt with implantations in pulmonary position and right ventricular reconstruction, which might be useful in the treatment of congenital heart defects. Implantation in the systemic – high pressure – circulation were only performed in small animals (rat model). One goat model showed some remarkable results, but only on very short time.
Conclusions: Tissue engineered valves seemed very promising, a promise that will not be fulfilled soon. Synthetic bioresorbable scaffolds have not left the laboratory yet. Scaffolds of biologic origin already have been tested in animals, mostly in pulmonary origin. It is by no means certain that behavior of tissue engineered valves in animals reflect the clinical situation, which is much more demanding. Also non-scientific hurdles such as official registration and commercialization of such devices have to be taken.. |
