Thin film metallic devices implantable within a human subject for occlusion of an aneurysm or blood vessel are provided. The devices are movable from a porous, elongated, collapsed configuration for delivery to a deployed configuration within the body. The pores telescope as the device moves to its deployed configuration, which causes the device to longitudinally foreshorten and radially expand, while also decreasing in porosity for preventing blood flow. The occlusion devices may be either self-supporting or supported by a strut structure. Additionally, the occlusion devices may comprise a plurality of layers having unaligned pore systems which further reduce porosity in the deployed configuration.
