| 摘要 |
A tiny electrically powered hydrodynamic blood pump is disclosed which occupies one third of the aortic or pulmonary valve position, and pumps directly from the left ventricle to the aorta or from the right ventricle to the pulmonary artery. The device is configured to exactly match or approximate the space of one leaflet and sinus of valsalva, with part of the device supported in the outflow tract of the ventricular cavity adjacent to the valve. In the configuration used, two leaflets of the natural tri-leaflet valve remain functional and the pump resides where the third leaflet had been. When implanted, the outer surface of the device includes two faces against which the two valve leaflets seal when closed. To obtain the best valve function, the shape of these faces may be custom fabricated to match the individual patient's valve geometry based on high resolution three dimensional CT or MRI images. Another embodiment of the invention discloses a combined two leaflet tissue valve with the miniature blood pump supported in the position usually occupied by the third leaflet. Either stented or un-stented tissue valves may be used. This structure preserves two thirds of the valve annulus area for ejection of blood by the natural ventricle, with excellent washing of the aortic root and interface of the blood pump to the heart. In the aortic position, the blood pump is positioned in the non-coronary cusp. A major advantage of the transvalvular VAD is the elimination of both the inflow and outflow cannulae usually required with heart assist devices. |
