A delivery system for an endoluminal device including an introducer, the introducer having a distal end intended to remain outside a patient in use and a proximal end. A stent graft having a first and second end is retained upon the introducer, the stent graft defining a fenestration disposed through a wall of the stent graft between the first and second end. A valve arrangement is disposed within an interior lumen of the stent graft about the fenestration. A retention system including a trigger wire engages and retains the valve arrangement away from the fenestration. The fenestration is in fluid communication with the interior lumen of the stent graft.
