Pediatric ventricular assist devices: current challenges and future prospects

Bürki, Sarah; Adachi, Iki

doi:10.2147/vhrm.s82379

Cited by 64 publications

(63 citation statements)

References 45 publications

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“…However, a high incidence of hemorrhagic and thrombotic complications was also noted. As a result, pediatric centers have just started implanting adult intracorporeal CF devices in children .…”

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confidence: 99%

The Progress in the Novel Pediatric Rotary Blood Pump Sputnik Development

et al. 2018

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In this work, the study results of an implantable pediatric rotary blood pump (PRBP) are presented. They show the results of the numerical simulation of fluid flow rates in the pump. The determination method of the backflows and stagnation regions is represented. The operating points corresponding to fluid flow rates of 1, 3, and 5 L/min for 75-80 mm Hg pressure head are investigated. The study results have shown that use of the pump in the 1 L/min operating point can potentially lead to the appearance of backflows and stagnation regions. In the case of using pumps in fluid flow rates ranging from 3 to 5 L/min, the number of stagnation regions decreases and the fluid flow rate changes marginally. Using the pump in this flow rate range is considered judicious. The study shows an increase in shear stress with an increase in fluid flow rates, while there is no increase in shear stress above the critical condition of 150 Pa (which does not allow us to reliably speak about the increased risk of blood cell damage). The aim of this work was to design, prototype, and study interaction of the Sputnik PRBP with the cardiovascular system. A three-dimensional model of Sputnik PRBP was designed with the following geometrical specifications: flow unit length of 51.5 mm, flow unit diameter of 10 mm, and spacing between the rotor and housing of 0.1 mm. Computational fluid dynamics studies were used to calculate head pressure-flow rate (H-Q) curves at rotor speeds ranging from 10 000 to 14 000 rpm (R = 0.866 between numerical simulation and experiment) and comparing flow patterns at various points of the flow rate operating range (1, 3, and 5 L/min) for operating pressures ranging from 75 to 80 mm Hg. It is noted that when fluid flow rate changes from 1 L/min to 3 L/min, significant changes are observed in the distribution of zero flow zones. At the inlet and outlet of the pump, when going to the operating point of 3 L/min, zones of stagnation become minuscule. The shear stress distribution was calculated along the pump volume. The volume in which shear stress exceed 150 Pa is less than 0.38% of the total pump volume at flow rates of 1, 3, and 5 L/min. In this study, a mock circulatory system (MCS) allowing simulation of physiological cardiovascular characteristics was used to investigate the interaction of the Sputnik PRBP with the cardiovascular system. MCS allows reproducing the Frank-Starling autoregulation mechanism of the heart. PRBP behavior was tested in the speed range of 6 000 to 15 000 rpm. Decreased contractility can be expressed in a stroke volume decrease approximately from 18 to 4 mL and ventricle systolic pressure decrease approximately from 92 to 20 mm Hg. The left ventricle becomes fully supported at a pump speed of 10 000 rpm. At a pump speed of 14 000 rpm, the left ventricle goes into a suction state in which fluid almost does not accumulate in the ventricle and only passes through it to the pump. The proposed PRBP showed potential for improved clinical outcomes in pediatric patients with a body surface area g...

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confidence: 99%

The Progress in the Novel Pediatric Rotary Blood Pump Sputnik Development

et al. 2018

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“…Primary graft dysfunction is reported as dysfunction affecting the right ventricle (RV), left ventricle (LV), or both, according to echocardiographic findings. Primary graft dysfunction (PGD) is common and ranges from 2.3 to 28.2% depending on the definition [6][7][8][9][10].…”

Section: Primary Graft Dysfunction 21 Definitions and Classificationmentioning

confidence: 99%

Mechanical Circulatory Support (MCS) for Primary Graft Dysfunction (PGD)

Canêo¹,

Barzilai²

2019

Advances in Extra-Corporeal Perfusion Therapies

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Primary graft dysfunction is the main cause of early mortality after heart transplantation (HT). Preventive strategies to avoid primary graft dysfunction (PGD) have been focused on better donor choice and maintenance, heart preservation methods in long-distance retrievals with prolonged ischemia time, and better myocardial protection during implantation, among others. Hemodynamic deterioration, caused by cardiogenic shock due to pump failure unresponsive to inotropes, has a catastrophic progression if not corrected in time. Severe PGD without response to inotropes and heart rhythm control in the absence of cardiac tamponade should be treated promptly with mechanical circulatory support. Extracorporeal life support (ECLS) should be installed early, before the occurrence of multiorgan dysfunction or prior to cardiac arrest, as highlighted in the literature.The aim of this chapter is to discuss the use of mechanical circulatory support (MCS) and its impact on the success to survival for patients with PGD.

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“…In other words, the main target population for the EXCOR in the current era is infants or small children weighing less than 20 kg. Depending on the size of the pump and required pump output, appropriate cannulas are to be selected (5,6,9, and 12 mm). The pump(s) is(are) then connected to the Ikus driving unit, which is a stationary unit for the Berlin Heart EXCOR that generates the suction and driving pressure to mobilize the membrane inside the pump.…”

Section: Device Mechanics Berlin Heart Excormentioning

confidence: 99%

“…For example, if required pump output is 1,200 mL/min, the best pump size would be 15 mL that can be run at 80 beats per minute (15 mL Â 80 equals 1,200 mL). 9 The details of anticoagulation management for this particular VAD will be discussed in the next section.…”

Section: Device Mechanics Berlin Heart Excormentioning

confidence: 99%

Management of Hemostasis for Pediatric Patients on Ventricular-Assist Devices

Adachi

Kostousov

Hensch

et al. 2017

Semin Thromb Hemost

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Ventricular-assist devices (VADs) have seen increased utilization in the pediatric population. Formerly, this therapeutic modality was limited to only the pulsatile VAD, EXCOR (Berlin Heart GmbH). However, the continuous flow VAD devices, HeartMate II (Abbott Inc.) and HeartWare (Medtronic Inc.), are now increasingly used in this population. Postoperatively, VAD patients are acutely anticoagulated using unfractionated heparin, often beginning 24 to 48 hours after VAD placement. Once the patient is stabilized and ready to transition to a lower acuity or outpatient setting, low-molecular-weight heparin or warfarin therapy may be instituted. Also, because of the risk for thrombotic and thromboembolic complications, antiplatelet strategies are employed using medications such as aspirin, clopidogrel, or dipyridamole. Platelet-rich plasma or whole blood platelet aggregation studies, platelet function analyzer-100 (Siemens), VerifyNow (Accriva Diagnostics), or thromboelastography platelet mapping (Haemonetics) may be used to help monitor antiplatelet effects, though the interpretation of the strength of the antiplatelet effect remains difficult. Care must be taken to monitor the hematologic complications of VAD, including acquired von Willebrand syndrome, which increases the risk for bleeding, and intravascular hemolysis, which increases the risk of thrombosis. Appropriate device placement and anticoagulation management are imperative to help avoid neurological dysfunction and ischemic stroke, the most devastating potential complications of VAD therapy. As our experience grows, we continue to gain an increased understanding of the management of anticoagulation, need for antiplatelet medication, and appropriate monitoring for these critical patients.

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Pediatric ventricular assist devices: current challenges and future prospects

Cited by 64 publications

References 45 publications

The Progress in the Novel Pediatric Rotary Blood Pump Sputnik Development

The Progress in the Novel Pediatric Rotary Blood Pump Sputnik Development

Mechanical Circulatory Support (MCS) for Primary Graft Dysfunction (PGD)

Management of Hemostasis for Pediatric Patients on Ventricular-Assist Devices

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