scholarly journals Hybrid membranes for the production of blood contacting surfaces: physicochemical, structural and biomechanical characterization

2021 ◽  
Vol 25 (1) ◽  
Author(s):  
Martina Todesco ◽  
Carlo Zardin ◽  
Laura Iop ◽  
Tiziana Palmosi ◽  
Pietro Capaldo ◽  
...  
Keyword(s):  
Artificial Heart ◽  
Point Of View ◽  
Total Artificial Heart ◽  
Circulatory Support ◽  
Hybrid Membranes ◽  
Ventricular Assist ◽  
Actuation System ◽  
Mechanical Circulatory Support Devices ◽  
End Stage ◽  
Porcine Pericardium

Abstract Background Due to the shortage of organs’ donors that limits biological heart transplantations, mechanical circulatory supports can be implanted in case of refractory end-stage heart failure to replace partially (Ventricular Assist Device, VAD) or completely (Total Artificial Heart, TAH) the cardiac function. The hemocompatibility of mechanical circulatory supports is a fundamental issue that has not yet been fully matched; it mostly depends on the nature of blood-contacting surfaces. Methods In order to obtain hemocompatible materials, a pool of hybrid membranes was fabricated by coupling a synthetic polymer (polycarbonate urethane, commercially available in two formulations) with a decellularized biological tissue (porcine pericardium). To test their potential suitability as candidate materials for realizing the blood-contacting surfaces of a novel artificial heart, hybrid membranes have been preliminarily characterized in terms of physicochemical, structural and mechanical properties. Results Our results ascertained that the hybrid membranes are properly stratified, thus allowing to expose their biological side to blood and their polymeric surface to the actuation system of the intended device. From the biomechanical point of view, the hybrid membranes can withstand deformations up to more than 70 % and stresses up to around 8 MPa. Conclusions The hybrid membranes are suitable for the construction of the ventricular chambers of innovative mechanical circulatory support devices.

scholarly journals Success of Thrombectomy in Management of Ischemic Stroke in Two Patients with SynCardia Total Artificial Heart in Bridge-to-Transplantation

2021 ◽  
Vol 8 (9) ◽  
pp. 126
Author(s):  
Brendan Le Picault ◽  
Charles-Henri David ◽  
Pierre-Louis Alexandre ◽  
Cédric Lenoble ◽  
Philippe Bizouarn ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Case Report ◽  
Artificial Heart ◽  
Mechanical Thrombectomy ◽  
Total Artificial Heart ◽  
Neurological Deficits ◽  
Circulatory Support ◽  
Hemorrhagic Complication ◽  
Bridge To Transplant ◽  
End Stage

Introduction: Circulatory assistance from a SynCardia Total Artificial Heart (SynCardia-TAH) is a reliable bridge-to-transplant solution for patients with end-stage biventricular heart failure. Ischemic strokes affect about 10% of patients with a SynCardia-TAH. We report for the first time in the literature two successful thrombectomies to treat the acute phase of ischemic stroke in two patients treated with a SynCardia-TAH in the bridge-to-transplant (BTT). Case report: We follow two patients with circulatory support from a SynCardia-TAH in the bridge-to-transplant for terminal biventricular cardiac failure with ischemic stroke during the support period. An early in-hospital diagnosis enables the completion of a mechanical thrombectomy within the first 6 h of the onset of symptoms. There was no intracranial hemorrhagic complication during or after the procedure and the patients fully recovered from neurological deficits, allowing a successful heart transplant. Conclusion: This case report describes the possibility of treating ischemic strokes under a SynCardia-TAH by mechanical thrombectomy following the same recommendations as for the general population with excellent results and without any hemorrhagic complication during or after the procedure.

Differences in Shear Stress, Residence Time and Estimates of Hemolysis Between Different Ventricular Assist Devices

2011 ◽  
Author(s):  
Katharine H. Fraser ◽  
Tao Zhang ◽  
Bartley P. Griffith ◽  
Zhongjun J. Wu
Keyword(s):  
Cardiovascular Disease ◽  
Mechanical Circulatory Support ◽  
Ventricular Assist Devices ◽  
Circulatory Support ◽  
Ventricular Assist ◽  
The Past ◽  
The Us ◽  
Mechanical Circulatory Support Devices ◽  
End Stage ◽  
Support Devices

Cardiovascular disease is the leading cause of mortality globally. Among various forms of cardiovascular disease, heart failure (HF) affects 5.7 million patients in the United States1. Despite optimal treatment, some patients still do not improve and the available therapies fail to control their symptoms; for them, cardiac transplantation may be the only option. However, only around 2200 transplants are performed in the US each year1, or only about 6% of the estimated 35,000 US patients who would benefit actually receive a heart. To address the need to support the circulation in patients with end-stage HF a wide variety of mechanical circulatory support devices (MCSDs) have been developed over the past four decades.

The Effect of Impeller Position on CFD Calculations of Blood Flow in Magnetically Levitated Centrifugal Blood Pumps

2010 ◽  
Author(s):  
Katharine H. Fraser ◽  
M. Ertan Taskin ◽  
Tao Zhang ◽  
J. Scott Richardson ◽  
Barry Gellman ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
The United States ◽  
Lifestyle Changes ◽  
Circulatory Support ◽  
Ventricular Assist ◽  
Bridge To Transplant ◽  
Mechanical Circulatory Support Devices ◽  
The Right ◽  
End Stage ◽  
Transcatheter Interventions

Cardiovascular disease is the leading cause of mortality globally. Among various forms of cardiovascular disease, heart failure (HF) affects 5.7 million patients in the United States with about 670,000 new patients diagnosed for the first time annually (1). The fatality rate for HF is high, with one in five people dying within 1 year (1). The number of deaths has increased (1) despite advances in surgical treatment and new pharmaceutical therapies. Many therapies are available to treat patients with HF, including lifestyle changes, medications, transcatheter interventions and surgery. However, despite optimal medical and surgical therapies, some patients still do not improve and the available therapies fail to control their symptoms; for them, cardiac transplantation may be the only treatment option. However, only approximately 2300 donor hearts become available each year resulting in around 2200 transplants (1), or only about 6% of the estimated 35,000 US patients who would benefit from a heart actually receiving a transplant. To address the need to support the circulation in patients with end-stage HF a wide variety of mechanical circulatory support devices (MCSDs) have been developed over the past four decades. These MCSDs have been developed as a bridge to transplant, a bridge to recovery, and as an end stage treatment. They can be implanted as a ventricular assist device (VAD) to support the left ventricle (LVAD) or the right ventricle (RVAD) or two devices are used to support both left and right ventricles (Bi-VAD).

Mechanical Bridge to Transplantation with the Vienna Heart in TAH and LVAD Configuration

1992 ◽  
Vol 15 (3) ◽  
pp. 147-167 ◽  
Author(s):  
A. Moritz ◽  
A. Rokitansky ◽  
H. Schima ◽  
A. Prodinger ◽  
G. Laufer ◽  
...  
Keyword(s):  
Artificial Heart ◽  
Clinical Problem ◽  
Left Ventricular ◽  
Total Artificial Heart ◽  
Circulatory Support ◽  
Ventricular Assist ◽  
Septic Focus ◽  
Left Ventricular Assist ◽  
Liver And Kidney ◽  
Kidney Insufficiency

The Vienna heart uses a vacuum formed, pellethane pulsatile ventricle and is available in left ventricular assist (LVAD) and total artificial heart (TAH) configurations. This device was used as mechanical support of the failing heart in nine patients intended for heart transplantation. In two patients with cardiomyopathy an orthotopic TAH was implanted; one survived despite severe preoperative ischemic liver damage, and the other died of sepsis. In seven patients an atrio-aortic LVAD was implanted; six had suffered an acute myocardial infarction with cardiogenic shock, and one could not be weaned off bypass. Three patients survived. These included one 65-year-old with incipient ARDS at operation, and a 40-year-old with preoperative liver and kidney insufficiency who was transplanted in septicemia. In this patient the septic focus, natural and artificial heart, were removed at transplantation. Four patients died. In one we were unable to establish satisfactory circulation, one died after failure of the transplanted heart, one suffered a lethal cerebral embolism and one developed multi-organ failure after repeated attacks of ventricular fibrillation. With the Vienna heart sufficient circulatory support could be established with cardiac outputs between 6 and 8 l/min for the TAH and 3.5 to 4.5 I/min for the LVAD. With this type of support an overall survival rate of 44% could be achieved. Mechanical hemolysis was not a clinical problem and no device failure occurred.

Design Optimization of a Novel Polymeric Prosthetic Heart Valve and a Ventricular Assist Device via Device Thrombogenicity Emulation

2013 ◽  
Author(s):  
Thomas E. Claiborne ◽  
Wei-Che Chiu ◽  
Marvin J. Slepian ◽  
Danny Bluestein
Keyword(s):  
Heart Valves ◽  
Anticoagulation Therapy ◽  
Prosthetic Heart Valve ◽  
Total Artificial Heart ◽  
Ventricular Assist Devices ◽  
Circulatory Support ◽  
Prosthetic Heart Valves ◽  
Ventricular Assist ◽  
Mechanical Circulatory Support Devices ◽  
Optimization Methodology

Thrombotic complications, such as hemorrhage or embolism, remain a major concern of blood contacting medical devices [1], including prosthetic heart valves (PHV) and mechanical circulatory support devices, e.g. ventricular assist devices (VAD) or the Total Artificial Heart (TAH) [2]. In most cases device recipients require life-long anticoagulation therapy, which increases the risk of hemorrhagic stroke and other bleeding disorders. In order to obviate the need for anticoagulants and reduce stroke risks, our group developed a unique optimization methodology, Device Thrombogenicity Emulation (DTE) [2–5]. With the DTE, the thrombogenic potential of a device is evaluated using extensive numerical modeling and calculating multiple platelet trajectories flowing through the device. The platelet stress-time waveforms are then emulated in our Hemodynamic Shearing Device (HSD) and their activation level is measured with our Platelet Activation State (PAS) assay. This provides a proxy validation of the simulation. We identify high shear stress producing regions within the device and modify its design to reduce or eliminate those potentially thrombogenic ‘hot-spots.’ Through an iterative process, we can optimize the device design prior to prototyping.

Sa1894 Gastrointestinal Bleeding in Ventricular Assist Device and Total Artificial Heart Implantations

2014 ◽  
Vol 146 (5) ◽  
pp. S-322
Author(s):  
Jatinder Lachar ◽  
Sanah Christopher ◽  
Maureen Flattery ◽  
Keyur Shah ◽  
Daniel G. Tang ◽  
...  
Keyword(s):  
Gastrointestinal Bleeding ◽  
Ventricular Assist Device ◽  
Artificial Heart ◽  
Total Artificial Heart ◽  
Assist Device ◽  
Ventricular Assist

Development of Mechanical Circulatory Support Devices: 55 Years and Counting

2021 ◽  
Vol 32 (4) ◽  
pp. 424-433
Author(s):  
Emalie Petersen
Keyword(s):  
Mechanical Circulatory Support ◽  
Left Ventricular ◽  
Ventricular Assist Devices ◽  
Circulatory Support ◽  
Left Ventricular Assist Devices ◽  
Ventricular Assist ◽  
Assist Devices ◽  
Left Ventricular Assist ◽  
Mechanical Circulatory Support Devices ◽  
Support Devices

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.

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