Patent ID: 7637937

Claim:
A method of treating a subject with a medical device for implantation in a body vessel of the venous system, said body vessel comprising an elliptical cross-section having a major axis and a minor axis wherein the cross-section of the body vessel can undergo change as a result of blood flowing therethrough, comprising the steps of: (a) radially compressing a medical device into a radially compressed delivery configuration, the medical device comprising (i) an elliptical annular frame having a tubular configuration defining a lumen about a longitudinal axis, the frame being movable between an expanded configuration and a compressed configuration, the frame in the expanded configuration having an elliptical cross- section having a major axis and a minor axis, where the frame has a first maximum radial distance along the major axis greater than a second maximum radial distance along the minor axis, the frame having a circular cross-section in the radially compressed delivery configuration, the frame including at least one annular ring member having at least two circumferential regions forming a closed ring frame, each circumferential region having a different radial compressibility, wherein the radial compressibility of the circumferential region along the major axis is greater than the radial compressibility along the minor axis, and (ii) one or two valve leaflets attached to the frame, the valve leaflet having a free edge unattached to the frame and positioned within the lumen of the frame along the major axis of the elliptical cross-section of the frame, the free edge of the one or more valve leaflets moveable in response to fluid flow through the lumen; (b) delivering the medical device in the radially compressed delivery configuration to a point of treatment within said body vessel of the venous system; and (c) deploying the medical device at the point of treatment by radially expanding the medical device from the radially compressed delivery configuration to a radially expanded configuration such that the major and minor axes of the frame are substantially aligned with the major and minor axes of said body vessel respectively, wherein the cross-section of the frame is configured to move between the elliptical cross-section and the circular cross-section to conform to the changing cross-section of said body vessel of the venous system.