Abstract 16506: A Defect of the Aortic Wall Regenerated by a Novel Warp Knitting Fabric Comprising a Combination of Biodegradable and Non-biodegradable Yarn

Introduction: Vascular wall regeneration has been attempted using various types of biodegradable materials and stem cells, but the results have been disappointing. Hypothesis: Aortic wall regeneration can be promoted by use of an elaborately designed synthetic cardiovascular patch (OFT patch). Methods: The OFT patch is made from an extensible warp-knitted fabric that is a combination of biodegradable (poly-L-lactic acid: PLLA) and non-biodegradable (polyethylene terephthalate: PET) yarn. The fabric was coated with gelatin crosslinked with glutaraldehyde to provide water resistance. The in vitro mechanical properties of the OFT patch were compared with those of currently used surgical patches. Part of the wall of the canine descending aorta was replaced with an OFT patch. The patch was explanted three months later for histological examination. Results: The OFT patch had excellent tensile strength, suture retention strength, and bending resistance that were equivalent to those of current patches. The aortic lumen of the explanted OFT patch was covered with smooth intimal tissue. Microscopic examination revealed ideal tissue regeneration characterized by layered smooth muscle cells and collagen fibers with tissue connection across the OFT patch with neo-arterioles in the early stage after implantation. There was little inflammatory reaction and no calcium deposition on the patch yarn, and no aneurysmal or stenotic changes in patch-implanted regions. Conclusions: Since the non-biodegradable yarn of the patch is program-designed to expand to quadruple its initial size, the regenerated vascular wall can grow in size as the biodegradable PLLA portion is absorbed. Our results suggest that the OFT patch is suitable for use as a surgical patch in pediatric cardiac surgery.