(OP 296) Tissue Engineered Vascular Prostheses

Objectives: Patency of shelf-ready small calibre vascular pros-theses is still sub-optimal. Vascular tissue engineering may be a new approach for improving vascular prostheses, however, biodegradable scaffolds are needed. The purpose of our study was to evaluate biocompatibility and thrombogenicity of the following electro-spun nanofibre polymer grafts: poly-dioxanone(PDS) co-polymer with polylactic-acid(PDS-PLA) or co-polymer with polycaprolactone(PDS-PCL) and to assess their in vivo vascular remodelling. Methods: These medical grade polymers were selected because of biomechanical strength, surgeon's handling, degradation, cellular ingrowth and tissue reaction in subcutaneous and vascular implantation models. In 27 Sprague Dawley rats, 2 mm-ePTFE grafts (n=9 controls), 2 mm-PDS-PLA grafts (n=9) and 2 mm-PDS-PCL grafts (n=9) were interposed in the infrarenal abdominal aorta for 3, 6 and 12 weeks. Digital substraction angiography was performed for patency assessment before euthanasia and grafts were harvested for morphologic and scanning electron microscopic examination. Results: Patency rates were excellent for all types of grafts (100%). Angiography at follow-up showed aneurysmal formation in one of three PDS-PLA grafts and none in PDS-PCL grafts. The neoendothelialization measured by morphometry was significantly increased in PDS-PLA and PDS-PCL compared to ePTFE grafts at 3-weeks (p