| 摘要 |
<p>A ventricular assist device (16) includes a pair of valved conduits (18, 20) and a pumping portion (14) connected by these conduits (18, 20) into the circulatory system of a host patient (10). The pumping portion (14) and valved conduits (18, 20) are constructed and configured to minimize the number of material-surface transitions which blood must cross in flowing through the device (16). Also, the valved conduits (18, 20) include porcine xenograft valves (102), which are externally supported by stending structure (100) located outside of the blood-contacting flow path of the device (16). A flexible shape-retaining inner wall member (46) of the valved conduits (18, 20) is impervious to blood, but defines a porous inner surface (48) on which a stable biological interface may form. Also, this inner wall member (46) is shaped with sinuses (114) which do not replicate either the porcine sinuses from which the xenograft valves (102) were taken, or human aortic sinuses. However, the sinuses of the inner wall member (46) are configured to provide effective valve action by the formation of vigorous vortices in the blood flow downstream of these valves, and to avoid the formation of clots on the blood-contacting surfaces of the valved conduits (18, 20).</p> |
