[Stentless bioprosthesis for aortic valve replacement]

The stentless aortic bioprosthesis was reported to reduce left ventricular mass (LVM) in the early period after implantation and have better hemodynamic performance and a larger effective orifice area (EOA) than stented valves. However, its clinical advantage over the stented valve is still unclear. We have implanted stentless bioprostheses in 61 patients and had a low operative mortality rate (1.6%). LVM index, left ventricular end-diastolic volume (LVEDV) index, left ventricular end-systolic volume (LVESV) index, and peak pressure gradient (PG) were rapidly reduced after implantation. Ten-year-freedom from cardiac-related death, thromboemolism, and structural valve deterioration rates were 91.0%, 100%, and 95.0%, respectively. Furthermore, using MRI analysis, blood velocity through stentless valves was similar to that through native aortic valves in comparison with stented valves. In conclusion, the stentless valve enables more physiologic blood flow through the valve, and thus it may be useful in patients with small annuli or those who require better hemodynamic performance to enable physical activity.