Abstract: A prosthesis (18) comprising stents (7,8) sutured to a graft (5) comprising a tube of biocompatible material. The stents are attached to the inside surface of the tube and there is at least one fenestration (10) in the tube corresponding to an intersecting artery opening. A further stent (1) extends proximally and may have caudally facing barbs (2). Each fenestration includes one or more radiopaque markers (11) defining a periphery of the fenestration. A release mechanism for the prosthesis includes trigger wires (15,17) stitched into a fold (16) on the material to retain the prosthesis in a partially compressed state during deployment. A delivery device (20) has a sheath (26) to hold the compressed prosthesis during insertion and a top cap (24) to retain the top stent (1).