Paravalvular leaks around prosthetic valves implanted in the mitral position: technical refinements of the ovine model.

Background And Aim Of The Study: Currently, the sheep model is preferred for preclinical in-vivo evaluation of prosthetic heart valves implanted in the mitral position. In sheep, the anatomy and tissue characteristics in, and around, the native mitral valve's posterior commissure (12:00-3:00 quadrant) makes valve implantation technically challenging. As the majority of non-infectious paravalvular leaks occurred in this quadrant, the surgical technique was modified to offer greater exposure of the annulus in this region and permit more accurate placement of sutures.

A juvenile sheep model for the long-term evaluation of stentless bioprostheses implanted as aortic root replacements.

Background And Aim Of The Study: Orthotopic valve replacement in large animals is an important component of the preclinical assessment of bioprosthetic valves. To provide the most useful preclinical information, the development of models that parallel clinical practice patterns is essential. Therefore, we sought to develop a technically feasible and reproducible model for chronic evaluation of stentless bioprosthetic aortic valves implanted as aortic root replacements in juvenile sheep.

A novel annuloplasty system with rigid and flexible elements: initial experimental results in sheep and the case for untreated autologous pericardium.

Background And Aims Of The Study: A precise annuloplasty is difficult to perform with pericardium as the ring material because unwanted plication of the pericardium itself typically occurs when the sutures are tied. A novel annuloplasty system has been developed which should allow a predictably precise measured plication of the annulus without plication of the pericardium itself. A feasibility study was designed to evaluate this new concept.

Feasibility evaluation of a new pericardial bioprosthesis with dye mediated photo-oxidized bovine pericardial tissue.

Background And Aims Of The Study: In an attempt to overcome the problem of calcification of bioprostheses, a novel bovine pericardial tissue valve preserved with a non-aldehyde, dye mediated photo-oxidation process (PhotoFixTM) developed by CarboMedics, Inc. The device was evaluated by implantation in the mitral position of juvenile sheep with a mean age of 3.5 months.