The invention relates to an implantable device to replace an organ valve,includingmain body openings at first and second ends thereof in fluid communicationwitheach other. A first membrane element allows fluid flow through the main bodyin afirst flow direction and blocks the flow in an opposed second flow direction.Themain body is reversibly transferable between first and second operatingstates. Inthe first operating state, the main body has a large ratio of length totransverseexpansion along the longitudinal axis of the main body. In the second state,suchratio is smaller. The main body is formed from a single wire-like element orfrom anumber of wire-like elements connected to each other by interlocking, winding,and/or twisting and/or weaving in the manner of a woven and/or layered fabricand/or net.
