Stent grafts and methods of deployment thereof are provided. The stent graft includes a tubular graft body having a graft wall defining a lumen extending between first and second end openings. A stent structure is coupled along the graft wall. A top stent includes a first portion coupled along an inner surface of the graft body at attachment locations, and a second portion extending beyond the first end opening outside of the graft body. The attachment locations are circumferentially spaced from one another in an annular pattern. An end of the stent structure is spaced from the first end opening by a clearance length. When the stent graft is in the radially expanded configuration, the first portion retracts to a retracted length from an extended length, and a portion of the second portion has a greater cross-sectional area and a different cross-sectional shape than the graft body.
