Various stents and stent-graft systems for treatment of medical conditions are disclosed. In one embodiment, an exemplary stent-graft system may be used for endovascular treatment of a thoracic aortic aneurysm. The stent-graft system may comprise proximal and distal components, each comprising a graft having proximal and distal ends, where upon deployment the proximal and distal components at least partially overlap with one another to provide a fluid passageway therebetween. The proximal component may comprise a proximal stent having a plurality of proximal and distal apices connected by a plurality of generally straight portions, where a radius of curvature of at least one of the proximal apices may be greater than the radius of curvature of at least one of the distal apices. The distal component may comprise a proximal z-stent coupled to the graft, where the proximal end of the graft comprises at least scallop formed therein that generally follows the shape of the proximal z-stent. Further, the distal component may comprise at least one z-stent stent coupled to the distal end of the graft and extending distally therefrom that reduces proximal migration of the distal component.