An endoluminal prosthesis includes a tubular main graft body (20) including a sidewall and proximal and distal ends with a first stent (30a) positioned near the proximal end of the main graft body, a second stent (30b) positioned adjacent to and distal of the first stent and an opening (50) in the sidewall positioned longitudinally between a peak of the first stent and a valley of the second stent. A tubular branch (60) is disposed in the opening and is flexibly orientable between a retrograde configuration in which a first end opening is oriented toward the distal end and a second end opening is oriented toward the proximal end and an antegrade configuration in which the first end opening is oriented toward the proximal end and the second end opening is oriented toward the distal end.