A valve prosthetic implant for treating a vein or other blood vessel includes a tubular, expandable anchoring frame extending from a proximal end to a distal end of the implant, a valve seat formed at or near the middle of the anchoring frame, an expandable ball disposed within the lumen of the anchoring frame, and a ball retention tether attached to the expandable ball and to the valve seat and/or the anchoring frame. The anchoring frame may include a cylindrical proximal portion at the proximal end, a cylindrical distal portion at the distal end, an inwardly angled inlet portion between the cylindrical proximal portion and a middle of the anchoring frame, and an inwardly angled outlet portion between the cylindrical distal portion and the middle of the anchoring frame.