Treatment of multiple organ failure by a totally implantable ventricular assist device

Multiple organ failure (MOF) becomes an important problem during clinical use of the ventricular assist device (VAD). To improve the clinical record of the VAD, the function of other organs may be vitally important. For that reason, we have been developing a VAD system aiming at improving the function of other organs. Development of the vibrating flow pump (VFP), which can generate a unique flow pattern from 10 to 50Hz, is still ongoing in our institute. In order to evaluate brain blood flow and oxygen consumption, oxyhemoglobin was measured with NIRO (Hamamatsu Photo.) in healthy adult goats. Four healthy adult goats were anesthetized with halothane inhalation, and left thoracotomy was performed for left heart bypass. Oxyhemoglobin in the brain was measured with the recording of the hemodynamic variables during left heart assistance with the VFP system. During left heart bypass with the VFP system, the hemodynamic parameters kept within the normal range, and satisfactory pump output was easily obtained. Pump output was kept within 40%-50% bypass to evaluate the effect of high-frequency oscillating assist flow on brain blood flow with the same cardiac output. Interesting results were observed during the experiments. During 30Hz driving of the VFP left heart assistance, oxyhemoglobin suggested that brain blood flow was significantly increased compared with another drive frequency with the same total cardiac output. These results suggest that we can control brain blood flow with a totally implantable VAD system such as the VFP system, which can control the frequency of the blood flow.