A bifurcated endovascular stent is formed from a pair of individual tubular component stents that can be placed independently in sequence in the branched region of a body vessel to form the bifurcated stent in situ. The first placed component stent includes a side opening and may be placed to extend both proximally and distally of the bifurcated junction with the side opening facing the entry to the branch vessel. The first component stent then is expanded within the vessel. The second component stent then can be advanced through the first component stent, through the side opening and into the branch vessel where it can be expanded. The portions of the first and second component stents that surround the region of the vessel juncture are constructed to provide enhanced lateral support for the walls of the vessel in the region of the junction. A delivery catheter is provided and includes a guidewire duct adapted to facilitate entry of a guidewire into the branch vessel while the first component stent is being deployed in the other lumen of the vessel.