Centrifugal Ventricular Assist Research Articles

Fifteen years of the first Brazilian Centrifugal Ventricular Assist Device for long term Mechanically Assisted Circulatory Support

More than simply being a review paper and telling the story of the development of a ventricular assist device, this paper aims to critically review changes in technical nomenclature and scientific positioning, taxonomy and its applications, therapeutic indications and the results of its application in patients. After 15 years of the first Brazilian Centrifugal Ventricular Assist Device, many things have changed for the better. Mechanically Assisted Circulatory Support is a therapy consolidated as a safe and effective alternative for the treatment of congestive heart failure, as well as heart transplantation and other drug therapies. It is still seen as science fiction in several countries or media, but that is a cruel reality in our post-truth and fake news times. In reality, it should receive more funding resources especially in developing countries and emerging economies with strong hospital industry of the cardiovascular field that may have surprising results with all the technology already established.

Invited Commentary

Left ventricular assist devices (LVADs) have improved outcomes for many patients with end-stage heart disease. Nevertheless, there is a subset of patients with biventricular failure for whom left ventricular support alone is insufficient. Predicting which patients will have refractory right ventricular failure after LVAD implantation can be challenging. However, because a delay in appropriate right ventricle support can lead to irreversible organ failure and death, many centers elect to mechanically support the right ventricle in high-risk patients undergoing LVAD surgery. In this study, Arabía and colleagues [1Arabía F.A. Milano C.A. Mahr C. et al.Biventricular support with intracorporeal, continuous flow, centrifugal ventricular assist devices.Ann Thorac Surg. 2018; 105: 548-556Abstract Full Text Full Text PDF PubMed Scopus (23) Google Scholar] used the Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) database to examine the outcomes of patients who had durable centrifugal continuous-flow (CCF) LVADs implanted in a biventricular configuration. This group was then compared with patients who had a temporary right ventricular assist device (RVAD) implanted at the time of LVAD surgery. Only 38 patients had biventricular durable devices reported over the period of this study. However, from the data available, the authors conclude that there is no difference between the temporary and durable implantable device groups in terms of overall survival or progression to transplantation. Although the numbers are small, this study serves as a much needed reference and will help to guide discussion about expected outcomes in patients who require biventricular mechanical support. That being said, the data supporting a durable LVAD implant in an RVAD configuration over a temporary RVAD are less convincing. The use of CCF LVADs in the RVAD configuration is tempting as it provides patients the opportunity for early ambulation and may be the only option for discharge home. These theoretic advantages, however, must be critically weighed against the high rates of device malfunction, which approach 30% in this series. One third of these required reoperation and pump exchange for presumed pump thrombosis. Certainly, there are temporary RVAD configurations that avoid femoral cannulation and patient immobility. Our preference for right ventricular support in a transplant candidate is to place temporary RVAD cannulas through tunneled thoracic grafts. This enables chest closure, early ambulation, and bedside decannulation in the event of right ventricle recovery. If CCF devices are to be used for right-side support, it is still unclear what the appropriate cannulation strategy should be. In this paper, it appears that a right atrial approach has a survival advantage over right ventricular cannulation, which is potentially related to device malfunction in the latter group. However, the sample size is too small to make meaningful conclusions at this point. Perhaps the most important point to be made about durable right-sided support is that the ideal pump does not yet exist. There is an opportunity for the development of RVADs that are specifically modeled for the unique characteristic of right-sided pressures and anatomy. Until that time, we will continue to benefit from studies such as this one that demonstrate clearly the outcomes of therapies for this complex patient population. Biventricular Support With Intracorporeal, Continuous Flow, Centrifugal Ventricular Assist DevicesThe Annals of Thoracic SurgeryVol. 105Issue 2PreviewThe incidence of right ventricular dysfunction requiring right ventricular assist device after left ventricular assist device placement has been reported between 10% to 30%. The mortality rate is higher compared with patients who require left ventricular assist device only; the most effective and safest biventricular assist device remains unknown. We aimed to determine the survival outcomes and frequency of adverse events in patients with two durable, intracorporeal, continuous flow centrifugal pumps for support. Full-Text PDF

Single-Centre Experience of Durable Bi-Ventricular Support with HeartWare Continuous Flow, Centrifugal Ventricular Assist Devices (HeartWare BiVADs)

Single-Centre Experience of Durable Bi-Ventricular Support with HeartWare Continuous Flow, Centrifugal Ventricular Assist Devices (HeartWare BiVADs)

(236) - Early Results of Biventricular Support with Durable, Intracorporeal Continuous Flow Centrifugal Ventricular Assist Devices: Analysis from INTERMACS

(236) - Early Results of Biventricular Support with Durable, Intracorporeal Continuous Flow Centrifugal Ventricular Assist Devices: Analysis from INTERMACS

(30) - Centrifugal Ventricular Assist Device Flow Rates

The use of ventricular assist devices (VADs) in pediatric heart failure (HF) has increased dramatically in recent years, despite high rates of morbidity and mortality. We reviewed all patients (pts) at our center who were placed on centrifugal continuous flow VADs (CentriMag, PediMag) to assess the relationship of flow rates to complications and outcomes.

Considerations on Afterload Management for Patients with Centrifugal Ventricular Assist Devices

This case report illustrates the challenges in managing patients with centrifugal ventricular assist devices (VADs). As these devices have evolved, their physical properties have changed, impacting patient management. Levitated centrifugal pumps have a non-linear response to afterloads. The device output will decrease significantly in the presence of high systemic vascular resistance. Blood pressure control is integral to the management of patients in the immediate and later postoperative period.

Letter to the Editor�Re: First Clinical Application of the DuraHeart Centrifugal Ventricular Assist Device for a Japanese Patient

Letter to the Editor�Re: First Clinical Application of the DuraHeart Centrifugal Ventricular Assist Device for a Japanese Patient

First Clinical Application of the DuraHeart Centrifugal Ventricular Assist Device for a Japanese Patient

The DuraHeart ventricular assist device (VAD) is a third-generation implantable centrifugal pump with a magnetically levitated impeller. Since February 2007, the device has been clinically applied with excellent results as a bridge to heart transplantation in Europe. As of this writing, however, the device has yet to be approved by the Ministry of Health, Labour and Welfare for clinical use in Japan. We herein report the first clinical application of this device for a Japanese patient. A 31-year-old man with dilated cardiomyopathy was transferred to the Heart and Diabetes Center NRW (HDZ-NRW) in Bad Oeynhausen, Germany, where he was to await heart transplantation. The transfer was safely completed under management with low-dose dopamine. His condition gradually deteriorated at HDZ-NRW, and the DuraHeart left ventricular assist device was implanted for the left ventricle at 7 weeks after admission. Shortly thereafter, however, on POD 7, a Thoratec VAD had to be inserted on the right side due to refractory right heart failure. The right ventricular assist device could be explanted after a 3-month assist, and the patient is now waiting for heart transplantation at home in Germany.

Computational Fluid Dynamic Analysis of the Flow around the Pivot Bearing of the Centrifugal Ventricular Assist Device (Effects of Design Variations of the Washout Hole, the Pivot and the Back Gap)

Flow mechanisms within a monopivot centrifugal pump were clarified in order to prevent stagnation around the pivot bearing, which may cause thrombogenesis. We focused on the geometric effects of the pump, which included the effects of the washout hole diameter, the pivot friction area and the back gap width of the impeller relative to the washout around the pivot bearing. Flow patterns were carefully examined around the pivot bearing, including the region inside the washout hole and the back gap of the impeller, by computational fluid dynamic analysis. Based on the results from the computational fluid dynamic analyses, we found that a balance relationship between the washout hole diameter and the back gap width of the impeller affected the secondary flow toward the pivot bearing that eliminated the stagnation around the pivot bearing. In addition, while increasing in the pivot friction area eliminated stagnation around the pivot bearing, it also increased hemolysis within the pump.

Characteristics and outcomes of patients bridged to cardiac transplantation on centrifugal ventricular assist devices: a case series of the early experience of one Canadian transplant centre.

Centrifugal ventricular assist devices (VADs) have been used successfully to bridge patients in cardiogenic shock to cardiac transplantation, though complications are frequent and often life-threatening. To describe characteristics and examine outcomes of patients bridged to cardiac transplantation on centrifugal VADs. A retrospective health record review was conducted on all adults over a 12 year period (N=20) placed on centrifugal VADs with the intent to bridge to cardiac transplantation at a major Canadian transplant centre. Complications of VAD support necessitated removal of 12 patients from the transplant list; seven (35%) survived to cardiac transplantation. Of the seven recipients, five survived to discharge and four remain alive and well. Bridging patients on centrifugal VADs to cardiac transplantation requires improvement, including maintaining patient stability during the period of early VAD institution, aggressively managing complications of VAD support, and consideration of long-term pulsatile devices. However, if patients survive to transplantation, good long-term outcomes are expected.

Use of a Rate‐Limited Ultrafiltration Circuit with Centrifugal Ventricular Assist

Renal insufficiency and pulmonary edema are frequently observed in patients who require centrifugal ventricular assist for postcardiotomy ventricular failure. We describe a technique of using a rate-limited ultrafiltration device in parallel with the assist device circuit to remove excess intravascular volume.

Autopsy findings in patients on postcardiotomy centrifugal ventricular assist.

Reported experience with ventricular assist devices (VAD) routinely includes the rate of thromboembolic events, which is commonly calculated from clinically evident findings. Fifty-four patients have had postcardiotomy circulatory support with the Sarns centrifugal device at our institution. We have reviewed 43 patients who failed to survive VAD support to compare the thromboembolism rate diagnosed clinically to that determined at autopsy. In the 35 patients who had no autopsy, there was one clinically apparent thromboembolic event (2.3%). In eight similar patients who had autopsy, there was no clinically apparent thromboembolism. Five of these eight patients (63%) had acute thromboembolic infarcts determined at autopsy. Three had evidence of pulmonary thromboembolism, two cerebrovascular infarction, two liver infarcts, two splenic infarcts, two kidney infarcts, and one each gastric, pancreatic, prostate, adrenal, cervical, and ileal infarcts. All had left and/or right ventricular infarctions. It is concluded that patients dying following VAD have commonly suffered perioperative myocardial infarction. When evaluating complications associated with VAD, one should consider that the true incidence of thromboembolic events is underestimated by clinical findings.