In-Silico Evaluation of Effects of Swirl Direction and Intensity on Aortic Flow Patterns Induced by an Aortic Pump Using Computational Fluid Dynamics

Author(s):  
Priti G. Albal ◽  
Prahlad G. Menon

Congestive heart failure has reached epidemic proportions in developed countries afflicting an estimated 23 million patients worldwide and more than 5.7 million patients suffering from it annually in USA. Left ventricular assist devices (LVADs) have gained acceptance for non-transplant NYHA Class III & IV HF patients to provide full or partial circulatory support as a bridge to transplant or destination therapy. Recently, investigators have suggested advantages of deploying a continuous flow pump within the aorta, through transcatheter deployment (eg: Abiomed Impella pump) and an anchoring device to lodge the pump across the diameter of the ascending aorta (AAo). In this study we evaluate feasibility of such a device anchored virtually at the AAo of a patient-specific aortic arch, using computational fluid dynamics (CFD). Constant inflow rate conditions of 0.7 m/s in the axial direction with varying swirl / tangential intensity at the AAo inlet (viz. pump outlet) was modeled simulative of a range of conditions affecting aortic helical grade (viz. secondary flow), using FLUENT 14.5 (ANSYS Inc.). A change of swirl intensity from +30% (right-handed, physiological) to −30% (left-handed) swirl led to increases in peak WSS (by 10.31%) and mean WSS (by 13.04%). This simulation based pilot study indicates that WSS in transverse aortic arch is a versatile indicator of non-physiological helical flow grade and may be a promising design parameter for hemodynamics-informed aortic pump design.

2017 ◽  
Vol 9 ◽  
pp. 117906521771421 ◽  
Author(s):  
Gabriel A Hernandez ◽  
Jonatan D Nunez Breton ◽  
Sandra V Chaparro

Advances in mechanical circulatory support devices provided the technology to develop long-term, implantable left ventricular assist devices as bridge to transplant, destination therapy, and in a lesser group of patients, as bridge to recovery. Despite the benefits from this innovative therapy, with their increased use, many complications have been encountered, one of the most common being infections. With the driveline acting as a portal to the exterior environment, an infection involving this structure is the most frequent one. Because patients with destination therapy are expected to receive circulatory support for a longer period of time, we will focus this review on the risk factors, prevention, and treatment options for driveline infections.


Nutrients ◽  
2021 ◽  
Vol 13 (3) ◽  
pp. 861
Author(s):  
Gennaro Martucci ◽  
Federico Pappalardo ◽  
Harikesh Subramanian ◽  
Giulia Ingoglia ◽  
Elena Conoscenti ◽  
...  

Heart failure (HF) remains a leading cause of morbidity, hospitalization, and mortality worldwide. Advancement of mechanical circulatory support technology has led to the use of continuous-flow left ventricular assist devices (LVADs), reducing hospitalizations, and improving quality of life and outcomes in advanced HF. Recent studies have highlighted how metabolic and endocrine dysfunction may be a consequence of, or associated with, HF, and may represent a novel (still neglected) therapeutic target in the treatment of HF. On the other hand, it is not clear whether LVAD support, may impact the outcome by also improving organ perfusion as well as improving the neuro-hormonal state of the patients, reducing the endocrine dysfunction. Moreover, endocrine function is likely a major determinant of human homeostasis, and is a key issue in the recovery from critical illness. Care of the endocrine function may contribute to improving cardiac contractility, immune function, as well as infection control, and rehabilitation during and after a LVAD placement. In this review, data on endocrine challenges in patients carrying an LVAD are gathered to highlight pathophysiological states relevant to this setting of patients, and to summarize the current therapeutic suggestions in the treatment of thyroid dysfunction, and vitamin D, erythropoietin and testosterone administration.


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.


Sign in / Sign up

Export Citation Format

Share Document