Stents and method of inserting a stent into a delivery catheter are disclosed. In a disclosed embodiment, a stent for redirecting blood flow away from an aneurysmal sac is provided. The stent comprises an elongate frame (2) that is radially contractable from a fully radially expanded state to a radially contracted state in a process involving elongation of the frame, wherein: the fully radially expanded state represents the state of the frame at body temperature when no external force is applied to the frame； in the radially contracted state the frame has a maximum lateral dimension that is at least 30% smaller than the maximum lateral dimension of the frame in the fully radially expanded state； and the frame comprises a low porosity region (4) for positioning at the opening to the aneurysmal sac, the low porosity region having a porosity of less than 50% when the frame is in the fully radially expanded state.
