Abstract 15849: Development of a New Aortic Valve Reconstruction Material Using In-Body Tissue Architecture

Background and PurposeAortic valve neocuspitization (AVNeoOzaki Procedure) using autologous pericardium treated with glutaraldehyde has resulted satisfactory clinical outcomes over the six years. However, for young patients, there are concerns about an insufficient amount of the pericardium in reoperation cases and decreased coaptation due to growth; the durability of the autologous pericardium is also unknown. In-body tissue architecture (IBTA), which is based on the phenomenon of tissue encapsulation of foreign materials, can prepare autologous prosthetic tissues that show potential for regeneration and growth in several animal models. This study aimed to develop a new leaflet material for ANeo using IBTA.MethodsMolds were subcutaneously embedded in goats. Several months later, collagenous connective tissue membranes (biosheets) had formed in the molds were obtained. After the entire thickness of the biosheets was determined using optical coherence tomography, AVNeo was performed using the portions of the sheets ranging from 0.20-0.35 mm in thickness. As a control, AVNeo was performed using autologous pericardium treated with glutaraldehyde.ResultsUsing biosheets that were 0.20-0.35 mm thick with little variation, the procedure was able to be performed with the same operability as autologous pericardium. Postoperative echocardiography showed that the mobility, pressure gradient and regurgitation of the biosheet models were not markedly different from those of the autologous pericardium models. Three months later, in autologous pericardium models, the pericardial tissue remained, and the numbers of αSMA-positive cells had increased around it ; in contrast, in the biosheet models, the tissue completely fused to the annulus with invasion by αSMA- positive cells. Six months later, the biosheet models showed further infiltration of αSMA-positive cells toward the leaflet along with the new appearance of elastic fibers at the left ventricular side and endothelial cells at the surface like the native valves.ConclusionBiosheets showed completely different reactions from autologous pericardium and may be useful as a new aortic valve reconstruction material changing into the native valve.