A multiple-sided medical device comprises a frame comprising wire or other resilient material and having a series of bends and interconnecting sides. The device has both a flat configuration and a second, folded configuration which a generally serpentine shape. The device is pushed from a delivery catheter into the lumen of a duct or vessel and may include one or more barbs for anchoring purposes. A full or partial covering of fabric or other flexible material such as DACRON, PTFE, or a collagen-based material such as small intestinal submucosa (SIS), may be sutured or attached to the frame to form an occlusion device, a stent graft, or an implantable, intraluminal valve such as for correcting incompetent veins in the lower legs and feet.