Figure 1.

Venus P, a trileaflet porcine pericardial valve on a self-expanding nitinol frame, went through three modifications. The initial modular design (I) consisting of separate midvalve segment connected to proximal and distal flare changed to unibody design (II) on a single nitinol frame. Thin porcine pericardial strips that lined the six open cells of distal flare were removed in the third (III) design. The recent design (IV) connected the sharp edges through nitinol wires to the five open cells in the distal flare. The midvalve segment of the first-generation modular design without the flares on either side formed the straight design valve