Experience With the Levitronix CentriMag in the Pediatric Population as a Bridge to Decision and Recovery

Extracorporeal membrane oxygenation, Berlin, and ventricular assist devices: a primer for the cardiologist

PURPOSE OF REVIEW

Mechanical circulatory support (MCS) has become an indispensable tool in the management of children with impending respiratory and cardiac failure. Though extracorporeal membrane oxygenation (ECMO) was classically the only form of support available to pediatric patients, considerable advances have allowed ventricular assist devices (VADs) to become increasingly utilized in children. This review provides an update of recent advances in ECMO and VAD management in children.

RECENT FINDINGS

The options for mechanical support in infants and small children with end-stage heart failure are limited. As such, the greatest advances in the past decade have come in the successful adoption of the Berlin Heart EXCOR device, with a marked improvement in survival to transplant over ECMO. Further advances have been made in the use of adult VADs in children. For instance, the HeartWare HVAD has been utilized in children as young as 3 years of age, despite being designed for use in adult patients.

SUMMARY

The availability of mechanical support options for children remains limited to ECMO and a small number of VADs. While outcomes of VAD support in pediatric patients have been promising, further study in smaller and more complex pediatric patients is necessary.

A Cost-effective and Reliable Method to Predict Mechanical Stress in Single-use and Standard Pumps

Pumps are mainly used when transferring sterile culture broths in biopharmaceutical and biotechnological production processes. However, during the pumping process shear forces occur which can lead to qualitative and/or quantitative product loss. To calculate the mechanical stress with limited experimental expense, an oil-water emulsion system was used, whose suitability was demonstrated for drop size detections in bioreactors(1). As drop breakup of the oil-water emulsion system is a function of mechanical stress, drop sizes need to be counted over the experimental time of shear stress investigations. In previous studies, the inline endoscopy has been shown to be an accurate and reliable measurement technique for drop size detections in liquid/liquid dispersions. The aim of this protocol is to show the suitability of the inline endoscopy technique for drop size measurements in pumping processes. In order to express the drop size, the Sauter mean diameter d32 was used as the representative diameter of drops in the oil-water emulsion. The results showed low variation in the Sauter mean diameters, which were quantified by standard deviations of below 15%, indicating the reliability of the measurement technique.

Ventricular assist device use in congenital heart disease with a comparison to heart transplant

Despite advances in medical and surgical therapies, some children with congenital heart disease (CHD) are not able to be adequately treated or palliated, leading them to develop progressive heart failure. As these patients progress to end-stage heart failure they pose a unique set of challenges. Heart transplant remains the standard of care; the donor pool, however, remains limited. Following the experience from the adult realm, the pediatric ventricular assist device (VAD) has emerged as a valid treatment option as a bridge to transplant. Due to the infrequent necessity and the uniqueness of each case, the pediatric VAD in the CHD population remains a topic with limited information. Given the experience in the adult realm, we were tasked with reviewing pediatric VADs and their use in patients with CHD and comparing this therapy to heart transplantation when possible.

Thoratec CentriMag for temporary treatment of refractory cardiogenic shock or severe cardiopulmonary insufficiency: a systematic literature review and meta-analysis of observational studies

The aim of the study was to systematically evaluate effect of CentriMag heart pump (Thoratec Corporation) as temporary ventricular assist device (VAD) and part of extracorporeal membrane oxygenation (ECMO) system on outcomes in patients with cardiac or cardiac-respiratory failure. A systematic search was conducted in five databases for the period 2003 to 2012. Fifty-three publications with data for 999 patients, supported with CentriMag, were included. In 72% studies, CentriMag was used as a VAD and in 25% as part of ECMO circuit. Mean duration of VAD support was 25.0 days in precardiotomy group, 10.9 days in postcardiac surgery cardiogenic shock group, 8.8 days in post-transplant graft failure and rejection group, and 16.0 days in post-LVAD placement right ventricular failure group. Survival on support was 82% (95% CI 70-92) for VAD support in precardiotomy cardiogenic shock indication, 63% (95% CI 46-78) in VAD support in postcardiac surgery cardiogenic shock indication, 62% (95% CI 46-76) in VAD support in post-transplant graft rejection or failure indication, and 83% (95% CI 73-92) in VAD support in post-LVAD placement right ventricular failure indication. CentriMag is an effective technology for temporary support of patients with cardiac and cardiorespiratory failure.

Use of short-term circulatory support as a bridge in pediatric heart transplantation

BACKGROUND

Heart transplantation is considered the gold standard therapy for the advanced heart failure, but donor shortage, especially in pediatric patients, is the main limitation for this procedure, so most sick patients die while waiting for the procedure.

OBJECTIVE

To evaluate the use of short-term circulatory support as a bridge to transplantation in end-stage cardiomyopathy.

METHODS

Retrospective clinical study. Between January 2011 and December 2013, 40 patients with cardiomyopathy were admitted in our Pediatric Intensive Care Unit, with a mean age of 4.5 years. Twenty patients evolved during hospitalization with clinical deterioration and were classified as Intermacs 1 and 2. One patient died within 24 hours and 19 could be stabilized and were listed. They were divided into 2 groups: A, clinical support alone and B, implantation of short-term circulatory support as bridge to transplantation additionally to clinical therapy.

RESULTS

We used short-term mechanical circulatory support as a bridge to transplantation in 9. In group A (n=10), eight died waiting and 2 patients (20%) were transplanted, but none was discharged. In group B (n=9), 6 patients (66.7%) were transplanted and three were discharged.The mean support time was 21,8 days (6 to 984 h). The mean transplant waiting list time was 33,8 days. Renal failure and sepsis were the main complication and cause of death in group A while neurologic complications were more prevalent en group B.

CONCLUSION

Mechanical circulatory support increases survival on the pediatric heart transplantation waiting list in patients classified as Intermacs 1 and 2.

Partial mechanical circulatory support in children

Partial mechanical support devices are capable of partially unloading only one ventricle, often the systemic one, in the setting of acute circulatory failure. They are rarely used in the pediatric population, as the mode of circulatory failure in patients with congenital heart disease often involves biventricular or a predominantly right ventricular component. The devices include intra-aortic balloon pumping, Impella, TandemHeart, and CentriMag. They are rarely used as a bridge-to-recovery, but more often as a bridge-to-decision, or bridge-to-conversion to full mechanical support systems, such as extracorporeal membrane oxygenation or ventricular assist devices. Currently, lack of availability of more complete support devices, cost issues, or lack of infrastructure and personnel may still be indications to continue using partial mechanical support as opposed to more complete forms of biventricular circulatory support.

First reported use of the heartware HVAD in the US as bridge to transplant in an adolescent

Limited options exist for mechanical circulatory support as a bridge to transplantation in pediatric patients with advanced heart failure. This is particularly true when it comes to intracorporeal technologies. We describe the first reported experience with the use of the HVAD in the US as a successful bridge to transplantation in a 13-yr-old patient.