The present embodiments provide a stent graft having a tubular configuration defining a lumen therethrough, the stent graft having a proximal section and a distal section. A folded section is positioned between the proximal section and the distal section. The folded section includes a first fold directed toward the distal end and engaged with the proximal section and a second fold directed toward the proximal end and engaged with the distal section. A valve arrangement is positioned in at least one of the first and second folds providing access from an exterior of the graft to the interior of the stent graft for insertion of an additional device.