Methods for increasing the patency of biodegradable, synthetic vascular grafts are provided. The methods include administering one or more cytokines and/or chemokines that promote outward tissue remodeling of the vascular grafts and vascular neotissue formation. The disclosed methods do not require cell seeding of the vascular grafts, thus avoiding many problems associated with cell seeding. Biodegradable, polymeric vascular grafts which provide controlled release of cytokines and/or chemokines at the site of vascular graft implantation are also provided.