Hemodynamic evaluation of a new pulsatile blood pump during low flow cardiopulmonary bypass support.

BACKGROUND: The VentriFlo® True Pulse Pump (VentriFlo, Inc, Pelham, NH, USA) is a new pulsatile blood pump intended for use during short-term circulatory support. The purpose of this study was to evaluate the feasibility of the VentriFlo and compare it to a conventional centrifugal pump (ROTAFLOW, Getinge, Gothenberg, Sweden) in acute pig experiments. METHODS: Pigs (40-45 kg) were supported by cardiopulmonary bypass (CPB) with the VentriFlo (n = 9) or ROTAFLOW (n = 5) for 6 h. Both VentriFlo and ROTAFLOW circuits utilized standard CPB components. We evaluated hemodynamics, blood chemistry, gas analysis, plasma hemoglobin, and microcirculation at the groin skin with computer-assisted video microscopy (Optilia, Sollentuna, Sweden). RESULTS: Pigs were successfully supported by CPB for 6 h without any pump-related complications in either group. The VentriFlo delivered an average stroke volume of 29.2 ± 4.8 ml. VentriFlo delivered significantly higher pulse pressure (29.1 ± 7.2 mm Hg vs. 4.4 ± 7.0 mm Hg, p < 0.01) as measured in the carotid artery, with mean aortic pressure and pump flow comparable with those in ROTAFLOW. In blood gas analysis, arterial pH was significantly lower after five hours support in the VentriFlo group (7.30 ± 0.07 vs. 7.43 ± 0.03, p = 0.001). There was no significant difference in plasma hemoglobin level in both groups after six hours of CPB support. In microcirculatory assessment, VentriFlo tended to keep normal capillary flow, but it was not statistically significant. CONCLUSIONS: VentriFlo-supported pigs showed comparable hemodynamic parameters with significantly higher pulse pressure compared to ROTAFLOW without hemolysis.

New Technology Mimics Physiologic Pulsatile Flow During Cardiopulmonary Bypass.

The VentriFlo True Pulse Pump (Design Mentor, Inc., Pelham, NH, USA) is the first blood pump designed to mimic human arterial waveforms in a standard oxygenation circuit. Our aim was to demonstrate the feasibility and safety of this pump in preparation for future studies to determine possible clinical advantages. We studied four piglets (41.4-46.2 kg): three with an implanted VentriFlo pulsatile pump and one with the nonpulsatile ROTAFLOW pump (MAQUET Holding B.V. & Co. KG, Rastatt, Germany) as a control. Hemodynamics was monitored during 6-h cardiopulmonary bypass (CPB) support and for 2 h after weaning off CPB. The VentriFlo demonstrated physiologic arterial waveforms with arterial pulse pressure of 24.6 ± 5.7 mm Hg. Pump flows (2.0 ± 0.1 L/min in ROTAFLOW; 1.9 ± 0.1 L/min in VentriFlo) and plasma free hemoglobin levels (27.9 ± 12.5 mg/dL in ROTAFLOW; 28.5 ± 14.2 mg/dL in VentriFlo) were also comparable, but systemic O2 extraction (as measured by arterial minus venous O2 saturation) registered slightly higher with the VentriFlo (63.2 ± 6.9%) than the ROTAFLOW (55.4 ± 6.5%). Histological findings showed no evidence of ischemic changes or thromboembolism. This pilot study demonstrated that the VentriFlo system generated pulsatile flow and maintained adequate perfusion of all organs during prolonged CPB.

Total artificial heart.

End-stage heart failure represents a highly morbid condition for the patient with limited treatment options. From a surgical perspective, the treatment options for effective long-term survival are usually limited to heart transplantation, heart-lung transplantation or implantation of a destination mechanical circulatory support device. Assuming an advanced heart-failure patient is indeed deemed a candidate for transplantation, the patient is subject to shortages in donor organ availability and thus possible further decompensation and potential death while awaiting transplantation. Various extracorporeal and implantable ventricular-assist devices (VADs) may be able to provide temporary or long-term circulatory support for many end-stage heart-failure patients but mechanical circulatory support options for patients requiring long-term biventricular support remain limited. Implantation of a total artificial heart (TAH) currently represents one, if not the best, long-term surgical treatment option for patients requiring biventricular mechanical circulatory support as a bridge to transplant. The clinical applicability of available versions of positive displacement pumps is limited by their size and complications. Application of continuous-flow technology can help in solving some of these issues and is currently being applied in the research towards a new generation of smaller and more effective TAHs. In this review, we discuss the history of the TAH, its development and clinical application, implications for anaesthetic management, published outcomes and the future outlook for TAHs.