ABSTRACT Arterial and venous reconstructions are frequently needed to reestablish circulation in various diseases, organ transplantations, interventional operations, trauma, etc. Autologous grafts, mostly saphenous veins, are the gold standard for vascular patches to reconstruct arteries and veins. The disadvantages of autologous venous patches, however, are obvious, including multiple surgeries, limitations on dimensions and numbers of donor sites, and donor complications. Synthetic and biological materials are used to supplement autologous patches in clinical practice but have a number of shortcomings. Synthetic patches have relatively high rate of occlusion and risk of pseudoaneurysm formation and infection which may require life-long follow up in susceptible populations. Biological materials have been used to reconstruct arteries and veins with variable outcomes which suggest the need for further refinement. In this Phase I SBIR proposal, we propose to evaluate the pulmonary visceral pleura (PVP) as a biological patch for reconstruction of arteries and veins in vascular surgery. The PVP plays an important role in lung function, and is inherently compliant and non-thrombogenic. Our preliminary data show that glutaraldehyde-fixed PVP patches implanted in carotid and femoral arteries and jugular veins maintained excellent 4-month patency and developed functional neo-endothelial and -smooth muscle cells. We hypothesize that the PVP patch will vascularize in-vivo and therefore provide long-term patency, since the non- thrombogenic nature of the structure of mesothelium and the biocompatibility of PVP patches to promote vascular tissue self-assembly. To test this hypothesis, we will validate the safety and efficacy of the PVP patches using conduit artery and vein in a translational swine model. We will carry out these studies in aged and hyperlipidemic swine model, since vascular repair or reconstruction are frequently needed in the aging patients with hyperlipidemic complications. This proposal addresses a clinically significant problem and successful completion will provide surgeons with various size options of patches for vascular surgery to ultimately improve patient outcomes. PVP is abundant (from swine, bovine, etc.) and can be fabricated into the desired sizes of vascular patches.