Long-Term Viability And Extensibility Of An In Situ Regenerated Canine Aortic Wall Using Hybrid Warp-Knitted Fabric

OBJECTIVES: Many surgical materials promoting tissue regeneration have been explored for use in paediatric cardiac surgery. The aim of this study is to evaluate the long-term viability and extensibility of the canine aortic wall regenerated using a novel synthetic hybrid fabric.METHODS: The sheet is a warp-knitted fabric of biodegradable (poly-l-lactic acid) and non-biodegradable (polyethylene terephthalate) yarns coated with cross-linked gelatine. This material was implanted as a patch to fill an oval-shaped defect created in the canine descending aorta. The tissue samples were explanted after 12, 24 or 36months (N=3, 2, 2, respectively) for histological examination and biomechanical testing.RESULTS: There was no shrinkage, rupture or aneurysmal change after 24months. The regenerated wall showed prototypical vascular healing without material degeneration, chronic inflammation, calcification or abnormal intimal overgrowth. Bridging tissue across the patch was well-formed and had expanded over time. The biodegradable yarns had completely degraded at 24months after implantation, as scheduled, but the regenerated aortic wall demonstrated satisfactory levels of mechanical strength and extensibility in tensile strength tests.CONCLUSIONS: The sheet achieved good long-term viability and extensibility in the regenerated aortic wall. These findings suggest that it is a promising surgical material for repairing congenital heart defects. Further developments of the sheet are required, including clinical studies.