Pediatric ventricular assist devices: what are the key considerations and requirements?

ABSTRACT

Introduction: The development of ventricular assist devices (VADs) have enabled myocardial recovery and improved patient survival until heart transplantation. However, device options remain limited for children and lag in development.

Areas covered: This review focuses on the evolution of pediatric VADs in becoming to be an accepted treatment option in advanced heart failure, discusses the classification of VADs available for children, i.e. types of pumps and duration of support, and defines implantation indications and explantation criteria, describes attendant complications and long-term outcome of VAD support. Furthermore, we emphasize the key considerations and requirements in the application of these devices in infants, children and adolescents.

Expert opinion: Increasing use of VADs has facilitated a leading edge in management of advanced heart failure either as a bridge to transplantation or as a bridge to myocardial recovery. In newborns and small children, the EXCOR Pediatric VAD remains the only reliable option. In some patients ventricular unloading may lead to complete myocardial recovery. There is a strong need for pumps that are fully implantable, suitable for single ventricle physiology, such as the right ventricle.

KEYWORDS:

• Anticoagulation
• congenital heart diseases
• cardiomyopathy
• heart failure
• heart transplantation
• myocardial recovery
• myocarditis
• thrombosis
• ventricular assist devices

Article highlights

• Berlin Heart EXCOR® Pediatric, is the only VAD which can be used for newborns, infants and small children ≤ 25 kg.

• Ventricular assist devices ensure patient survival until heart transplantation becomes possible, with comparable long-term post-transplant survival as those undergoing primary heart transplantation.

• Myocardial recovery is more likely feasible for children <2 years of age and those with biopsy-proven myocarditis

• Implantation of the BVAD in infants and small children is a challenging endeavor, because of the small pericardial space, possibly resulting in the positioning of the four cannulae after reconstructive surgery becoming complex.

• Young children on long-term VAD need repeated exchanges of the system to a larger size to accommodate growth, reflecting the lack of devices addressing the anatomic and physiologic needs of children. Use of adult VADs in children remains limited as they remain too large.

• Anticoagulation management is imperative, not only to allow for significant postnatal development of the hemostatic system in children but also to obviate the risk of thromboembolic complications inherently induced by VAD–blood interactions.

• Neurologic dysfunction is one of the most prevalent adverse events in children on VADs, and it often determines outcome.

• The miniaturized pump and tube system showed an increased thrombogenicity due to the small caliber of tubes, cannulae and chambers which is more pronounced in the small sized pumps in comparison to adult size pumps.

• The initial experience with implantable axial-flow VADs indicated that there were unique issues with the pediatric device and pediatric recipient that preclude universal application of the management principles conceived for the adult device, i.e. risks and treatment for thrombus formation, timing of implantation, consideration of patient’s size, device design, chest space, pump thrombosis and anticoagulation management.

• In adult VADs implanted to children, the most commonly observed adverse events were bleeding, renal dysfunction, need for a longer duration of ventilator support, right ventricular failure and pump thrombosis.

Declaration of interest

The authors have no relevant affiliations or financial involvement with any organization or entity with a financial interest in or financial conflict with the subject matter or materials discussed in the manuscript. This includes employment, consultancies, honoraria, stock ownership or options, expert testimony, grants or patents received or pending, or royalties.

Reviewer disclosures

One peer reviewer was a consultant in the NIH funded Jarvik 2015 study. Peer reviewers on this manuscript have no other relevant financial relationships or otherwise to disclose.

Additional information

Funding

This paper was not funded.