The AB Portable Driver Generates Higher Drive-Line Pressures Possibly Leading to Accelerated Hemolysis

The AB5000 Circulatory Support System is paracorporeal pulsatile ventricular assist device. The AB Portable Driver is a portable console for this system. We experienced two cases with accelerated hemolysis while receiving support by the AB Portable Driver. The purpose of this study was to clarify the mechanical differences associated with the hemolysis between the AB5000 console and the AB Portable Driver. The mock circulatory system modeled by an AB5000 ventricle and a blood sampling bag of vinyl chloride was run with an AB5000 console or AB Portable Driver. The peak drive-line pressure, the mean arterial cannula pressure and the pumping rate of the VAD were recorded. The AB5000 console generated a peak drive-line pressure of 280-300 mm Hg in LVAD mode and 210-220 mm Hg in RVAD mode, approximately 100 mm Hg lower than officially documented. In contrast, the AB Portable Driver generated pressures of 310-330 mm Hg in LVAD mode and 230-250 mm Hg in RVAD mode, 65-95 mm Hg higher than officially documented. The AB Portable Driver console generates higher drive-line pressures than the AB5000 console, possibly explaining the accelerated hemolysis.

Biventricular mechanical support devices--clinical perspectives

Cardiac transplantation remains the optimal treatment for end stage heart failure in selected patients. However, the shortage of donor hearts, rigorous eligibility criteria and long waiting lists have increased the demand for alternative treatment strategies such as mechanical circulatory support. While many patients are adequately supported with left ventricular assist devices, frequently there is right heart failure or involvement of the right ventricle, requiring biventricular support. Pulsatile flow biventricular devices and total artificial hearts approved for temporary biventricular support have limitations including size, high rates of adverse events and restricted mobility which makes them unsuitable for long term support. A number of centres have reported dual continuous flow left ventricular assist devices as a means of supporting the left and right heart. This review will summarise the literature on the outcomes and complications from current biventricular support devices and assess the role of dual continuous flow VAD therapy, and the new continuous flow total heart replacement devices.

Current status of extracorporeal ventricular assist devices in Japan

Extracorporeal VADs are less expensive, their prices reimbursable by the health insurance being about one-sixth of those of implantable VADs in Japan. However, a disadvantage is that, in Japan, their use is restricted to hospitals, necessitating prolonged hospitalization, reducing the patients' quality of life. According to the Japanese registry for Mechanically Assisted Circulatory Support, the survival rate does not differ significantly between patients with extracorporeal and implantable VADs. As in Europe and North America, extracorporeal VADs in Japan are commonly used as Bridge to Decision or Bridge to Recovery. Extracorporeal VADs are switched to implantable VADs as a Bridge-to-Bridge strategy after stabilization or when cardiac function recovery fails. They are also used as right ventricular assist devices (RVADs) in patients with right heart failure. A special characteristic of extracorporeal VADs in Japan is their frequent use as a Bridge to Candidacy. In Japan, indications for implantable VADs are restricted to patients registered for heart transplantation. Therefore, in patients who cannot be registered for transplantation because of transient renal dysfunction, etc., due to heart failure, extracorporeal VADs are used first, and then replaced by implantable VADs after transplant registry is done. Here, we describe the current status of extracorporeal VADs in Japan, focusing on the environmental backgrounds, along with a review of the relevant literature.