A prosthesis can comprise an expandable frame, a plurality of distal anchors and a plurality of proximal anchors. The anchors can extend outwardly from the frame. The frame can be configured to radially expand and contract for deployment within a body cavity. The frame and anchors can have one of many different shapes and configurations. For example, when the frame is in an expanded configuration, the proximal anchors can extend a significant distance away from the exterior of the frame, such as a length equal to or greater than about one half the diameter of the frame. As another example, the anchors can have looped ends.