Background: Autologous pericardium is widely used as a plastic material in intracardiac structures, in the pulmonary artery, and in aortic valve leaflets. For aortic valve reconstruction (AVRec) using the Ozaki procedure, it has produced excellent clinical results over a 10-year period. In-body tissue architecture (iBTA), which is based on the phenomenon of tissue encapsulation of foreign materials, can be used to prepare autologous prosthetic tissues. In this preliminary study, we examined whether biosheets can be used as valve leaflet material for glutaraldehyde-free AVRec by subchronic implantation experiments in goats and evaluated its performance compared with glutaraldehyde-treated autologous pericardium for AVRec.
Methods: Biosheets were prepared by embedding molds for two months into the dorsal subcutaneous spaces of goats. Autogenic biosheets (n = 4) cut into the shape of the valve were then implanted to the aortic valve annulus of four goats for three months without glutaraldehyde treatment. Autologous pericardium (n = 4) was used in four goats as a control. Valve function was observed using echocardiography.
Results: All goats survived the three-month study period. With biosheets, the leaflet surfaces were very smooth and, on histology, partially covered with a thin neointima (including endothelial cells). Biosheets were more thoroughly assimilated into the aortic root compared with autologous pericardium.
Conclusions: For the first time, biosheets were used for large animal AVRec. Biosheets could function as leaflets in the aortic position and may have the ability to assimilate into native valves.
Keywords: Aortic root; Tissue Engineering; Valve repair; Valve replacement.