Development of an implantable undulation type ventricular assist device for control of organ circulation.

It is well known that a rotary blood pump (RP) is effective as a small ventricular assist device (VAD). It might be still more effective if pulsation was available. The undulation pump (UP), which is a type of small RP, can also produce pulsation. In Japan, a development project for an implantable type UP ventricular assist device (UPVAD) is now advanced. Six universities and some companies together have been in charge of the development project for 5 years. In this study, the influence which the UP under development has on circulation in internal organs was investigated. Goats with the same weight as an average Asian person were used for the experiment. The left chest cavity was opened after resection of the fourth rib and the heart was approached. A cannula was inserted in the left ventricle from the apex. An outflow cannula was inserted into the left descending aorta. Heart muscle was excised using a newly developed puncher. The UPVAD was implanted using a left-heart bypass system. The myocardial blood flow, carotid arterial blood flow, and the kidney blood flow were recorded together with an electrocardiogram, blood pressure, and the flow rate. In these animal experiments, the blood circulation dynamic state was stabilized and sufficient support of the left heart was observed. Myocardial blood flow, carotid arterial flow, and a kidney blood flow increase resulting from UPVAD support was observed. Often the problem of multiple organ failure is important at the time of clinical application of a ventricular assist device. Assisting circulation to internal organs is important for prevention of multiple organ failure. It was concluded that the UPVAD might be useful for prevention of multiple organ failure.