Implantable valve for treating venous insufficiency having a self-expanding frame encased in polymer having a distal section for blood in-flow, a bulbous center section and a proximal section for blood out-flow. Polymeric leaflets have proximal ends forming a valve outlet which opens and closes in response to venous blood flow and distal portions integral with the inner polymer surface of the distal end of said bulbous section. The leaflets define a predominantly biomimetic sinus region with the bulbous section. Opening of the valve induces flushing of blood from the sinus region for smooth non-traumatic blood flow through said valve.
