Design, Modeling, and Experimental Characterization of A Valveless Pulsatile Flow Mechanical Circulatory Support Device

2021 ◽  
Vol 15 (2) ◽  
Author(s):  
Mengtang Li ◽  
Ye Chen ◽  
Marvin J. Slepian ◽  
Joseph Howard ◽  
Seth Thomas ◽  
...  

Abstract Mechanical circulatory support (MCS) devices, i.e., ventricular assist devices (VADs) and total artificial hearts (TAHs), while effective and vital in restoring hemodynamics in patients with circulatory compromise in advanced heart failure, remain limited by significant adverse thrombotic, embolic and bleeding events. Many of these complications relate to chronic exposure, via these devices, to nonpulsatile flow and the high shear stress created by current methods of blood propulsion or use of prosthetic valves. Here we propose a novel noncompressing single sliding vane MCS device to: 1) dramatically reduce pump operating speed thus potentially lowering the shear stress imparted to blood; 2) eliminate utilization of prosthetic valves thus diminishing potential shear stress generations; 3) allow direct flow rate control to generate physically desired blood flow rate include pulsatile flow; and 4) achieve compactness to fit into the majority of patients. The fundamental working principle and governing design equations are introduced first with multiple design and performance objectives presented. A first prototype was fabricated and experimental tests were conducted to validate the model with a 93.10% match between theoretical and experimental flow rate results. After model validation, the proposed MCS was tested to illustrate the ability of pulsatile flow generation. Finally, it was compared with some representative MCS pumps to discuss its potential of improving current MCS design. The presented work offers a novel MCS design and paves the way for next steps in device hemocompatibility testing.

Perfusion ◽  
2020 ◽  
Vol 35 (6) ◽  
pp. 474-483
Author(s):  
Inge Köhne

Since the use of continuous flow blood pumps as ventricular assist devices is standard, the problems with haemolysis have increased. It is mainly induced by shear stress affecting the erythrocyte membrane. There are many investigations about haemolysis in laminar and turbulent blood flow. The results defined as threshold levels for the damage of erythrocytes depend on the exposure time of the shear stress, but they are very different, depending on the used experimental methods or the calculation strategy. Here, the results are resumed and shown in curves. Different models for the calculation of the strengths of erythrocytes are discussed. There are few results reported about tests of haemolysis in blood pumps, but some theoretical approaches for the design of continuous flow blood pumps according to low haemolysis have been investigated within the last years.


Author(s):  
Einar Gude ◽  
Arnt E. Fiane

AbstractHeart failure with preserved ejection fraction (HFpEF) is increasing in prevalence and represents approximately 50% of all heart failure (HF) patients. Patients with this complex clinical scenario, characterized by high filling pressures, and reduced cardiac output (CO) associated with progressive multi-organ involvement, have so far not experienced any significant improvement in quality of life or survival with traditional HF treatment. Left ventricular assist devices (LVAD) have offered a new treatment alternative in terminal heart failure patients with reduced ejection fraction (HFrEF), providing a unique combination of significant pressure and volume unloading together with an increase in CO. The small left ventricular cavity in HFpEF patients challenges left-sided pressure unloading, and new anatomical entry points need to be explored for mechanical pressure and volume unloading. Optimized and pressure/volume-adjusted mechanical circulatory support (MCS) devices for HFrEF patients may conceivably be customized for HFpEF anatomy and hemodynamics. We have developed a long-term MCS device for HFpEF patients with atrial unloading in a pulsed algorithm, leading to a significant reduction of filling pressure, maintenance of pulse pressure, and increase in CO demonstrated in animal testing. In this article, we will discuss HFpEF pathology, hemodynamics, and the principles behind our novel MCS device that may improve symptoms and prognosis in HFpEF patients. Data from mock-loop hemolysis studies, acute, and chronic animal studies will be presented.


2019 ◽  
Vol 57 (1) ◽  
pp. 183-188 ◽  
Author(s):  
Charles-Henri David ◽  
Astrid Quessard ◽  
Ciro Mastroianni ◽  
Guillaume Hekimian ◽  
Julien Amour ◽  
...  

Abstract OBJECTIVES Postcardiotomy cardiogenic shock (PCCS) is associated with high mortality rates of 50–80%. Although veno-arterial extracorporeal membrane oxygenation has been used as mechanical circulatory support in patients with PCCS, it is associated with a high rate of complications and poor quality of life. The Impella 5.0 and Impella Left Direct (LD) (Impella 5.0/LD) are minimally invasive left ventricular assist devices that provide effective haemodynamic support resulting in left ventricular unloading and systemic perfusion. Our goal was to describe the outcome of patients with PCCS supported with the Impella 5.0/LD at La Pitié-Salpêtrière Hospital. METHODS We retrospectively reviewed consecutive patients supported with the Impella 5.0/LD for PCCS between December 2010 and June 2015. Survival outcome and in-hospital complications were assessed. RESULTS A total of 29 patients (63 ± 14 years, 17% women) with PCCS were supported with the Impella 5.0/LD. At baseline, 69% experienced chronic heart failure, 66% had dilated cardiomyopathy and 57% had valvular disease. The mean EuroSCORE II was 22 ± 17 and the ejection fraction was 28 ± 11%. Most of the patients underwent isolated valve surgery (45%) or isolated coronary artery bypass grafting (38%). The mean duration of Impella support was 9 ± 7 days. Weaning from the Impella was successful in 72.4%, and 58.6% survived to discharge. Recovery of native heart function was observed in 100% of discharged patients. Survival to 30 days and to 1 year from Impella implant was 58.6% and 51.7%, respectively. CONCLUSIONS The Impella 5.0 and the Impella LD represent an excellent treatment option for critically ill patients with PCCS and are associated with favourable survival outcome and native heart recovery.


2014 ◽  
Vol 8s1 ◽  
pp. CMC.S15718 ◽  
Author(s):  
Nisha A. Gilotra ◽  
Gerin R. Stevens

Cardiogenic shock remains a challenging disease entity and is associated with significant morbidity and mortality. Temporary mechanical circulatory support (MCS) can be implemented in an acute setting to stabilize acutely ill patients with cardiomyopathy in a variety of clinical situations. Currently, several options exist for temporary MCS. We review the indications, contraindications, clinical applications, and evidences for a variety of temporary circulatory support options, including the intra-aortic balloon pump (IABP), extracorporeal membrane oxygenation (ECMO), CentriMag blood pump, and percutaneous ventricular assist devices (pVADs), specifically the TandemHeart and Impella.


2021 ◽  
Vol 32 (4) ◽  
pp. 424-433
Author(s):  
Emalie Petersen

Heart failure is a leading cause of morbidity and mortality in the United States. Treatment of this condition increasingly involves mechanical circulatory support devices. Even with optimal medical therapy and use of simple cardiac devices, heart failure often leads to reduced quality of life and a shortened life span, prompting exploration of more advanced treatment approaches. Left ventricular assist devices constitute an effective alternative to cardiac transplantation. These devices are not without complications, however, and their use requires careful cooperative management by the patient’s cardiology team and primary care provider. Left ventricular assist devices have undergone many technological advancements since they were first introduced, and they will continue to evolve. This article reviews the history of different types of left ventricular assist devices, appropriate patient selection, and common complications in order to increase health professionals’ familiarity with these treatment options.


2018 ◽  
Vol 39 (suppl_1) ◽  
Author(s):  
H Spillemaeker ◽  
A Dupont ◽  
A Kauskot ◽  
A Rauch ◽  
F Vincent ◽  
...  

2018 ◽  
Vol 42 (3) ◽  
pp. 133-142 ◽  
Author(s):  
Gemma Radley ◽  
Sabrina Ali ◽  
Ina Laura Pieper ◽  
Catherine A Thornton

Heart failure remains a disease of ever increasing prevalence in the modern world. Patients with end-stage heart failure are being referred increasingly for mechanical circulatory support. Mechanical circulatory support can assist patients who are ineligible for transplant and stabilise eligible patients prior to transplantation. It is also used during cardiopulmonary bypass surgery to maintain circulation while operating on the heart. While mechanical circulatory support can stabilise heart failure and improve quality of life, complications such as infection and thrombosis remain a common risk. Leukocytes can contribute to both of these complications. Contact with foreign surfaces and the introduction of artificial mechanical shear stress can lead to the activation of leukocytes, reduced functionality and the release of pro-inflammatory and pro-thrombogenic microparticles. Assessing the impact of mechanical trauma to leukocytes is largely overlooked in comparison to red blood cells and platelets. This review provides an overview of the available literature on the effects of mechanical circulatory support systems on leukocyte phenotype and function. One purpose of this review is to emphasise the importance of studying mechanical trauma to leukocytes to better understand the occurrence of adverse events during mechanical circulatory support.


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