A pre-loaded delivery device that facilitates accurate placement of a stent graft assembly in the aorta is disclosed. A stent graft is carried on the delivery device and held in a pre-deployment configuration by a sheath. A split in the sheath facilitates the pre-cannulation of one or more branch arteries extending from the aorta before the stent graft is fully released in the aorta. The stent graft comprises a tubular body having at least one scalloped fenestration formed in one end of the graft material and at least one fenestration formed in the graft material of the main tubular body. A helical internal side branch extends from the fenestration within the lumen of the main tubular body. The helical side branch is configured to curve at least partially around the scalloped fenestration. The assembly further comprises a connection stent graft extending from the fenestration into a branch vessel.