A stent assembly includes support rings each having interconnected circumferentially alternating inner prongs and outer prongs. The inner prongs define an inner diameter around a longitudinal axis. The outer prongs define an outer diameter greater than the inner diameter. A graft engages the support rings and follows a waving peripheral path. The graft may be a billowing graft. A second graft may surround the first graft such that tunnels are defined between the first graft and second graft. A method of making a stent assembly includes diametrically expanding the support rings onto a mandrel, engaging a graft with the support rings, and removing the support rings and graft from the mandrel permitting the stent assembly to contract to a neutral state.
