The present invention relates to an endoluminal prosthesis to be deployed at a vessel bifurcation, comprising a one-piece graft sleeve with a branching portion, defining a first prosthesis lumen and having, in its deployed state, a first diameter, said branching portion being reinforced by stent elements, and a trunk portion, defining a second prosthesis lumen in fluid communication with said first prosthesis lumen and having, in its deployed state, a second diameter. Said trunk portion is essentially free from reinforcing stent-material (FIG. 4).
