Early stenosis of Medtronic Mosaic bioprosthesis in the aortic position.

The Medtronic Mosaic valve (Medtronic, Inc, Minneapolis, Minn) is a third-generation stented porcine bioprosthesis combining physiologic fixation and a-amino-oleic acid antimineralization treatment to improve hemodynamic performance and durability. Despite encouraging short-term and midterm clinical results, however, there has been a heightened interest in the safety and efficacy of this device after a recent case series study of early valve failure resulting from an unknown cause. We present here 2 case reports of early structural valve dysfunction after implantation of the Mosaic valve in the aortic position.