Study on in vitro performance verification protocol for left ventricular assist device

2019 ◽  
Vol 43 (4) ◽  
pp. 242-251
Author(s):  
Shu Li ◽  
Po-Lin Hsu ◽  
Ye Hao ◽  
Haiping Ren

Objective: In vitro performance verification of ventricular assist devices using a mock circulatory loop is a prominent step to guarantee the system responses and the device performance and safety before the in vivo tests and ultimately clinical trials. Methods: In this article, we performed a comprehensive literature research to establish a verification matrix consisting of 12 test cases, defined by a set of physiological parameters which are commonly used to characterize a physiological condition. The clinical hemodynamic indicators for defining successful mechanical support were used as the acceptance criteria. A mock circulatory loop was customized to simulate the test cases, and a full verification protocol was described in details. An example left ventricular assist device was incorporated in the loop to accomplish a standard ventricular assist device performance verification. Result: The test cases based on clinical data with sufficient safety margin represent our understanding in defining the extremes of operation. The mock circulatory loop was capable of generating the test conditions in the verification matrix and reproducing the Frank–Starling law of the native heart. The effect of the left ventricular assist device assistance (characterized by the total systemic flow, mean aortic pressure, and left atrial pressure) was well verified by the proposed protocol and acceptance criteria. Conclusion: To date, all left ventricular assist devices made in China have been evaluated according this protocol and some of them have entered the clinical trial stage. We are closely observing the clinical data in order to further improve the performance of the platform and encourage more advances in mechanical circulatory assist devices.

2018 ◽  
Vol 42 (3) ◽  
pp. 113-124 ◽  
Author(s):  
Matteo Selmi ◽  
Wei-Che Chiu ◽  
Venkat Keshav Chivukula ◽  
Giulio Melisurgo ◽  
Jennifer Ann Beckman ◽  
...  

Introduction: Despite significant technical advancements in the design and manufacture of Left Ventricular Assist Devices, post-implant thrombotic and thromboembolic complications continue to affect long-term outcomes. Previous efforts, aimed at optimizing pump design as a means of reducing supraphysiologic shear stresses generated within the pump and associated prothrombotic shear-mediated platelet injury, have only partially altered the device hemocompatibility. Methods: We examined hemodynamic mechanisms that synergize with hypershear within the pump to contribute to the thrombogenic potential of the overall Left Ventricular Assist Device system. Results: Numerical simulations of blood flow in differing regions of the Left Ventricular Assist Device system, that is the diseased native left ventricle, the pump inflow cannula, the impeller, the outflow graft and the anastomosed downstream aorta, reveal that prothrombotic hemodynamic conditions might occur at these specific sites. Furthermore, we show that beyond hypershear, additional hemodynamic abnormalities exist within the pump, which may elicit platelet activation, such as recirculation zones and stagnant platelet trajectories. We also provide evidences that particular Left Ventricular Assist Device implantation configurations and specific post-implant patient management strategies, such as those allowing aortic valve opening, are more hemodynamically favorable and reduce the thrombotic risk. Conclusion: We extend the perspective of pump thrombosis secondary to the supraphysiologic shear stress environment of the pump to one of Left Ventricular Assist Device system thrombosis, raising the importance of comprehensive characterization of the different prothrombotic risk factors of the total system as the target to achieve enhanced hemocompatibility and improved clinical outcomes.


2020 ◽  
Vol 2020 (9) ◽  
Author(s):  
Lea Timmermann ◽  
Moritz Schmelzle ◽  
Evgenij Potapov ◽  
Marcus Müller ◽  
Christian Lojewski ◽  
...  

Abstract Successful implementation of left ventricular assist devices lead to a prolonged survival in patients with chronic terminal heart failure. Thus, patients with pre-existing left ventricular assist devices with abdominal comorbidities requiring abdominal surgery, e.g. for malignancy, are upcoming issues. We carried out a major liver resection for hepatocellular carcinoma in a patient with pre-existing left ventricular assist device. The importance of this case report is that it outlines the significance of oncologic resections in patients with left ventricular assist devices as an upcoming issue and provides an interdisciplinary approach.


Medicina ◽  
2020 ◽  
Vol 56 (9) ◽  
pp. 424
Author(s):  
Rafal Berger ◽  
Attila Nemeth ◽  
Christoph Salewski ◽  
Rodrigo Sandoval Boburg ◽  
Metesh Acharya ◽  
...  

Background and Objectives: Since the first use of ventricular assist devices (VADs) as bridge to recovery and bridge to cardiac transplantation in the early 1990s, significant technological advances have transformed VAD implantation into a routine destination therapy. With improved survival, many patients present for cardiac surgery for conditions not directly related to their permanent mechanical circulatory support. The aim of this study was to analyze the indications and outcomes of non-cardiac surgeries (NCSs) of left ventricular assist device (LVAD) patients in tertiary center. Material and Methods: We present a single-center experience after 151 LVAD implantations in 138 consecutive patients between 2012–2019 who had to undergo NCS during a follow-up period of 37 +/− 23.4 months on left ventricular assist device (LVAD). Results: A total of 105 procedures was performed in 63 LVAD recipients, resulting in peri-operative mortality of 3.8%. Twenty-five (39.7%) of patients underwent multiple surgeries. We found no significant difference in cumulative survival associated with the performed surgical interventions (p = 0.469). Conclusion: We demonstrated good overall clinical outcomes in LVAD patients undergoing NCS. With acceptable peri-operative mortality, NCS can be safely performed in LVAD patients on long-term support.


2019 ◽  
Vol 57 (1) ◽  
pp. 176-182
Author(s):  
Sinan Sabit Kocabeyoglu ◽  
Umit Kervan ◽  
Dogan Emre Sert ◽  
Mehmet Karahan ◽  
Emre Aygun ◽  
...  

Abstract OBJECTIVES The aim of this study was to examine the haemodynamic effects of preoperative levosimendan infusion in patients who underwent left ventricular assist device implantation and evaluate the prognoses. METHODS Between May 2013 and October 2018, 85 adult patients who underwent left ventricular assist device implantation were included; 44 and 41 patients suffered from dilated cardiomyopathy and ischaemic cardiomyopathy, respectively. Patients were divided into 2 groups: group A (58 patients) included those who received levosimendan infusion in addition to other inotropes and group B (27 patients) included those who received inotropic agents other than levosimendan. Levosimendan infusion was started at a dose of 0.1 µg⋅kg−1⋅min−1 for a maximum of 48 h without a bolus. The primary outcome was early right ventricular failure (RVF). The secondary outcomes were in-hospital mortality, need for right ventricular assist device, late RVF and recovery of end-organ functions. The safety end points of levosimendan included hypotension, atrial fibrillation, ventricular tachycardia or fibrillation and resuscitated cardiac arrest. RESULTS Patient characteristics were similar in both groups. No significant differences between groups were observed in the rates of early mortality, RVF, need for right ventricular assist device, cardiopulmonary bypass time and intensive care unit stay. Survival rates at 30 days, 1 year and 3 years and freedom from late RVF were similar between the groups. Administration of levosimendan was safe, generally well-tolerated and not interrupted because of side effects. CONCLUSIONS Levosimendan therapy was well-tolerated in patients who received permanent left ventricular assist devices. Combined preoperative therapy with inotropes and levosimendan significantly improves end-organ functions.


2015 ◽  
Vol 42 (6) ◽  
pp. 572-574
Author(s):  
Heidi J. Reich ◽  
Aamir Shah ◽  
Babak Azarbal ◽  
Jon Kobashigawa ◽  
Jaime Moriguchi ◽  
...  

Evolving technology and improvements in the design of modern, continuous-flow left ventricular assist devices have substantially reduced the rate of device malfunction. As the number of implanted devices increases and as survival prospects for patients with a device continue to improve, device malfunction is an increasingly common clinical challenge. Here, we present our initial experience with an endovascular microaxial flow left ventricular assist device as a successful bridge to transplantation in a 54-year-old man who experienced left ventricular assist device malfunction.


2020 ◽  
Vol 24 (4) ◽  
pp. 355-359
Author(s):  
Kaitlin M Flannery ◽  
Komal Kamra ◽  
Katsuhide Maeda ◽  
Paul Shuttleworth ◽  
Christopher Almond ◽  
...  

We present the successful perioperative management of an 11-year-old patient presenting for heart transplant with a left ventricular assist device, symptomatic acquired von Willebrand syndrome, and recent preoperative intracranial hemorrhage. A brief review of the pathophysiology of acquired von Willebrand syndrome is included. As the number of pediatric patients supported with ventricular assist devices continues to increase, the management of symptomatic acquired von Willebrand syndrome during the perioperative period is an important consideration for anesthesiologists.


2019 ◽  
Vol 28 (1) ◽  
pp. 15-21 ◽  
Author(s):  
Archana Puri ◽  
Raj Tobin ◽  
Shameek Bhattacharjee ◽  
Mukul Chandra Kapoor

Left ventricular assist devices are implanted in patients with chronic left heart failure refractory to maximal medical therapy. These devices were initially meant as bridge-to-transplant therapy, but with technological advances they are now also used as destination therapy. With improved survival, many patients with implanted devices need noncardiac surgery. We present three representative cases of noncardiac surgery in such patients to highlight the issues involved in their management. We also review the contemporary literature on various aspects of perioperative management. Anesthesia for noncardiac surgery in these patients was initially the domain of cardiac anesthesiologists, but with an increasing number of such patients needing surgery, general anesthesiologists are frequently tasked to provide anesthetic care. An understanding of left ventricular assist device physiology and issues unique to these patients is essential for safe management of these cases.


2018 ◽  
Vol 8 (4) ◽  
pp. 369-378 ◽  
Author(s):  
Rajkumar Doshi ◽  
Avneet Singh ◽  
Rajiv Jauhar ◽  
Perwaiz M Meraj

Background: The interventional treatment of complex high-risk indicated patients is technically difficult and can result in poor outcomes. Thus, percutaneous left ventricular assist devices are being increasingly used to provide hemodynamic support. No data is available comparing male and female for Complex High-risk Indicated Patients treated with percutaneous left ventricular assist devices. Our goal was to evaluate in-hospital as well as short term outcomes comparing males and females. Methods: There were 160 complex high-risk indicated patients with percutaneous left ventricular assist device use who were not in cardiogenic shock. A total of 132 male and 28 female patients were included. Ejection fraction below 35% with one additional criterion such as use of atherectomy device or treatment on unprotected left main disease or multi-vessel disease were our inclusion criteria. An Impella 2.5 or Impella CP (Abiomed Inc.) device was used as a left ventricular support device. Results: There was no difference in in-hospital mortality between the genders after performing a propensity score matched analysis (8.3% vs. 12.5%, p=0.54). Secondary outcomes of myocardial infarction, cardiogenic shock, congestive heart failure, dysrhythmia, major adverse cardiac events and composite of all complications were higher in males. Furthermore, 30-day survival was similar in males and females (88.9% vs. 87.5%, p=0.31). In addition, worse complications rates and survival were noted in patients with incomplete revascularization compared with those patients with complete revascularization in both gender. Conclusion: This study demonstrated no gender difference in clinical outcomes when using percutaneous left ventricular assist device support for the treatment of complex high-risk indicated patients. Overall, males had higher secondary outcomes compared with females with no difference in in-hospital mortality or 30-day survival rates.


Sign in / Sign up

Export Citation Format

Share Document