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 using heat or pressure welding crimping, adhesive, or other techniques 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.