An apparatus for treating an aneurysm in a blood vessel includes an occlusion element configured to be releasably coupled to an elongate delivery shaft and configured to be delivered in a collapsed configuration through an inner lumen of a delivery catheter, the occlusion element including an inverted mesh tube having an outer layer and an inner layer, the outer layer transitioning to the inner layer at an inversion fold, wherein at least the outer layer is formed into a first expanded shape including: a smooth outer cylinder configured to engage a wall of an aneurysm throughout a 360° circumference; and a substantially distal-facing surface including one or more heat-formed undulations, the one or more undulations configured to apply a radial force on the wall of the aneurysm.