An intraluminal vascular graft is structure to be deployable within a vessel for incorporation therein without use of hooks or barbs. The intraluminal vascular graft structure comprises a tubular body formed of a biocompatible material and a frame structure, having both circumferential support and longitudinal support structures, which support the graft at a distal end thereof and upwardly from the distal end. The vascular graft also includes a porous collar which have sufficient porosity to promote and enhance ingrowth of tissue and other materials into the porous collar from the surrounding vessel environment, thereby facilitating incorporation of the intraluminal vascular graft into the vessel wall. The tubular body of the intraluminal vascular graft may include one or more leg portions suitable for repairing bifurcated vessels which, in conjunction with the circumferential and longitudinal support structures, and the porous collar, assure positioning and support of the vascular graft within the vessel and against the crotch of the bifurcation. The intraluminal vascular graft is designed to form a tight seal between the graft and inner vessel wall, especially at the upstream end of the graft, to prevent perigraft leakage and formation of pseudoaneurysms around the graft.