Design of an Implantable Blood Pump for Mechanical Circulatory Support in Pediatric Patients

2017 ◽  
Author(s):  
Trevor A. Snyder ◽  
Phillip Coghill ◽  
Kooroush Azartash-Namin ◽  
Jingchun Wu ◽  
J. Ryan Stanfield ◽  
...  
Keyword(s):  
Heart Failure ◽  
Continuous Flow ◽  
Mechanical Circulatory Support ◽  
Pediatric Patients ◽  
Pediatric Population ◽  
Right Heart Failure ◽  
Ventricular Assist Devices ◽  
Circulatory Support ◽  
Hydrodynamic Characteristics ◽  
Vaned Diffuser

While the use of pulsatile- and continuous-flow ventricular assist devices (VADs) has become widely accepted as an acceptable treatment for end-stage heart failure in adults over the last three decades, the technology development for pediatric-specific patients is lagging behind that of adult devices. Only one pulsatile-flow VAD has been approved for use in pediatric patients in the U.S., just five years ago [1]. One continuous-flow device was approved specific to this population under Humanitarian Device Exemption (HDE), but is not in clinical use today [2]. As continuous-flow rotary blood pumps (RBPs) have become commonplace for mechanical circulatory support (MCS) in adults due to smaller size and greater reliability, significant resources have gone into the development of RBPs for pediatric use [3]. Further, RBPs designed for adult MCS have been used off-label in pediatric patients [4]. Development of an implantable device specific to a pediatric population includes challenges of anatomic placement and fixation. We have developed a RBP for adult MCS specific to right heart failure using computational fluid dynamics (CFD) and flow visualization [5]. The miniaturized device includes a rotating impeller and a vaned-diffuser in a 7 mm axial hydraulic diameter. As seen in Figure 1, the hydrodynamic characteristics suitable for a right-VAD (RVAD) may also be suitable for pediatric patients. Currently, the only approved device is placed extracorporeal due to size constraints in the intended population [1]. This report shows results of computational simulations for anatomic fit and fluid flow studies of our device geometry in pediatric patients.

Mechanical Circulatory Support: Heart Failure Therapy “in Motion”

2016 ◽  
Vol 11 (5) ◽  
pp. 305-314 ◽  
Author(s):  
Stephan M. Ensminger ◽  
Gino Gerosa ◽  
Jan F. Gummert ◽  
Volkmar Falk
Keyword(s):  
Heart Failure ◽  
Adverse Events ◽  
Continuous Flow ◽  
Mechanical Circulatory Support ◽  
First Generation ◽  
Ventricular Assist Devices ◽  
Circulatory Support ◽  
Destination Therapy ◽  
Flow Devices

Because the first generation of pulsatile-flow devices was primarily used to bridge the sickest patients to transplantation (bridge-to-transplant therapy), the current generation of continuous-flow ventricular assist devices qualifies for destination therapy for patients with advanced heart failure who are ineligible for transplantation. The first-generation devices were associated with frequent adverse events, limited mechanical durability, and patient discomfort due device size. In contrast, second-generation continuous-flow devices are smaller, more quiet, and durable, thus resulting in less complications and significantly improved survival rates. Heart transplantation remains an option for a limited number of patients only, and this fact has also triggered the discussion about the optimal timing for device implantation. The increasing use of continuous-flow devices has resulted in new challenges, such as adverse events during long-term support, and high hospital readmission rates. In addition, there are a number of device-related complications including mechanical problems such as device thrombosis, percutaneous driveline damage, as well as conditions such as hemolysis, infection, and cerebrovascular accidents. This review provides an overview of the evolution of mechanical circulatory support systems from bridge to transplantation to destination therapy including technological advances and clinical improvements in long-term patient survival and quality of life. In addition, recent changes in device implant strategies and current trials are reviewed and discussed. A brief glimpse into the future of mechanical circulatory support therapy will summarize the innovations that may soon enter clinical practice.

scholarly journals Can mechanical circulatory support be an effective treatment for HFpEF patients?

2021 ◽  
Author(s):  
Einar Gude ◽  
Arnt E. Fiane
Keyword(s):  
Heart Failure ◽  
Ejection Fraction ◽  
Mechanical Circulatory Support ◽  
Left Ventricular ◽  
Ventricular Assist Devices ◽  
Left Ventricular Cavity ◽  
Circulatory Support ◽  
Left Ventricular Assist Devices ◽  
Mechanical Pressure ◽  
Entry Points

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.

scholarly journals Haemolysis induced by mechanical circulatory support devices: unsolved problems

Perfusion ◽  
2020 ◽  
Vol 35 (6) ◽  
pp. 474-483
Author(s):  
Inge Köhne
Keyword(s):  
Shear Stress ◽  
Continuous Flow ◽  
Mechanical Circulatory Support ◽  
Ventricular Assist Devices ◽  
Circulatory Support ◽  
Ventricular Assist ◽  
Theoretical Approaches ◽  
Blood Pumps ◽  
Mechanical Circulatory Support Devices ◽  
Support Devices

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.

scholarly journals Mechanical Circulatory Support in Advanced Heart Failure

2021 ◽  
pp. 263246362110327
Author(s):  
Sonali Arora ◽  
Auras R. Atreya
Keyword(s):  
Heart Failure ◽  
Cardiogenic Shock ◽  
Heart Transplantation ◽  
Medical Therapy ◽  
Mechanical Circulatory Support ◽  
Advanced Heart Failure ◽  
Ventricular Assist Devices ◽  
Circulatory Support ◽  
Ventricular Assist ◽  
Advanced Therapies

Advanced heart failure (HF) with persistent and progressive clinical decline despite maximal medical therapy portends a high mortality in the absence of advanced therapies, such as ventricular assist devices or heart transplantation. A subset of these advanced HF patients deteriorates into refractory cardiogenic shock, that is challenging to manage with vasoactive agents alone. Temporary mechanical circulatory support (MCS) device options have evolved over the years and provide a viable option to rescue and rest the myocardium of patients in cardiogenic shock. The goal of such therapy is to serve as bridge to recovery, or more often, a bridge to durable advanced therapies. For those patients with progressive advanced HF despite extensive medical therapy, durable MCS devices (ventricular assist devices) are available when heart transplantation is not feasible. In this article, we review currently available temporary and durable MCS devices, with a focus on their hemodynamic profiles, to inform optimal device selection for patients with advanced HF.

Sign in / Sign up

Export Citation Format

Share Document