Abstract 3450: A New Valvular Substitute Based on Detergent Decellularized Human Aortic Allografts
Objectives: Our successful clinical use of decellularized human pulmonary heart valves expands the interest for creation of a bioartificial aortic valve graft. In this study we reported successful generation of decellularized conduits based on human aortic valves and the comparison of decellularization protocols of both valvular grafts.
Methods and Results: Seven human aortic (HAVC) and pulmonary valve conduits (HPVC) harvested from non-beating heart donors were treated using two detergents (Hanover protocol). Ten washing cycles (WC) in Ringer solution during 5 days were used to remove cellular and detergent remnants. Decellularization and washing steps were performed at room temperature under continuous shaking conditions. Decellularized cusps and wall were investigated to demonstrate the quality of decellularization process, maintenance of scaffold composition and architectonic. Tissue toxicity was controlled by reseeding with human venous endothelial cells (HVEC). Detergent treatment of HAVC and HPVC resulted in complete loss of cusp and wall cellularity after 36 and 48h respectively. DNA-assay revealed reduction of DNA content for more then 96% in HAVC and 98% in HPVC as compared to native tissue. Prolonged treatment in HAVC group influence minimally scaffold architectonic of the cusps, preservation of collagen and elastic fibers as shown in Hematoxylin-Eosin, Elastica van Gieson and Pentachrom stainings. EM and immunohistostaining for Collagen I, Laminin and Collagen-IV revealed effective preservation of scaffold components as well the basement membrane over the entire luminal surface of the decellularized grafts in both groups. In both groups, the absence of matrix toxicity after 10 WC was demonstrated by efficient adhesion and growing capacity of HVEC after reseeding on decellularized scaffolds.
Conclusion: In conclusion, decellularized and nontoxic aortic valve conduit may be achieved using Hanover protocol. However, an individual modification is necessary dependent on type of tissue. These results may be a promising contribution for clinical valve replacement and TE of aortic heart valves.