Ventricular cardiac-assist devices in infants and children: anesthetic considerations

Pediatric Ventricular Assist Device Implantation: An Anesthesia Perspective

Background

Ventricular assist devices (VADs) are increasingly being implanted in children, yet there is little literature to guide anesthetic management for these procedures.

Aims

To describe the pediatric population presenting for VAD implantation and the anesthetic management these patients receive. To compare (a) children under and over 12 months of age and (b) children with and without congenital heart disease.

Methods

Retrospective review of patients aged 0 to 17 years who underwent VAD implantation at a single center between 2014 and 2019.

Results

Seventy-seven VADs were implanted in 68 patients (46 left VADs, 24 biventricular VADs, 6 right VADs, and 1 univentricular VAD). One procedure was abandoned. Preoperatively, 20 (26%) patients were supported with extracorporeal membrane oxygenation and 57 (73%) patients were ventilated. Intraoperative donor blood products were required in 74 (95%) cases. Postimplantation inotropic support was required in 66 (85%) cases overall and 46 (100%) patients receiving a left VAD. Infants under 12 months were more likely to require preoperative extracorporeal membrane oxygenation (42% vs 19%), have femoral venous access (54% vs 28%), receive an intraoperative vasoconstrictor (42% vs 24%), and have delayed sternal closure (63 vs 22%). Mortality was higher in patients under 12 months (25% vs 19%) and in patients with congenital heart disease (25% vs 20%).

Conclusions

Children undergoing VAD implantation require high levels of preoperative organ support, high-dose intraoperative inotropic support, and high-volume blood transfusion. Children under 12 months and those with congenital heart disease are particularly challenging for anesthesiologists and have worse overall outcomes.

Ventricular Assist Devices and Anesthesia

Ventricular assist devices (VADs) have revolutionized longterm care for patients with congestive heart failure. These patients represent about 1% of the adults in the United States, considering that heart failure is a contributing factor in more than 250,000 deaths annually. It has been estimated that about 60,000 patients per year in the United States could benefit from heart transplantation or long-term mechanical support. Because of the short supply of donor hearts for transplant, assist devices have become of great value. At least four assist devices are clinically available, and two other devices are being investigated. Because cardiopulmonary bypass is required for implantation of these devices, anesthetizing these critically compromised patients requires extensive monitoring, skillful anesthetic management, and expert postoperative care.

Anesthetic management of children with in situ Berlin Heart EXCOR

Modern mechanical devices can support children with severely impaired cardiac function until a donor heart is found for transplantation or native function recovers. Pediatric heart transplantation offers a good chance of survival with a high quality of life to individuals with limited life expectancy and/or severe limitation to daily activities, but many die on the transplant list or are not listed because of a shortage of donor organs. In recent cohorts, there is better outcome when ventricular assist devices (VADs) rather than extracorporeal membrane oxygenation are used as a 'bridge' to transplantation. Anesthesiologists working in centers where VADs are available may increasingly be asked to provide anesthesia to children with such devices in situ, including procedures outside the cardiac surgical operating room. The Berlin Heart EXCOR device is a VAD system with increasing popularity in pediatric practice and has system components available in sizes suitable even for neonates. Postimplantation considerations include hemodynamics, thromboembolic complications and their prevention by anticoagulation, antimicrobial therapy, and the rehabilitation and mobilization of recipients. VAD-specific emergencies must be recognized and managed appropriately by anesthesiologists looking after Berlin Heart recipients. These include malignant dysrhythmias, sudden loss of VAD output, air or clot embolism, and sudden cyanosis. Provision of anesthesia for patients with an in situ Berlin Heart requires attention to particular considerations in preoperative assessment, induction, maintenance, and postoperative care.

Perioperative management of ventricular assist devices in children and adolescents

Ventricular assist devices are an integral part of therapy for patients with end-stage heart failure. Devices can either bridge to recovery or to transplantation. Options for ventricular assist devices include those that are centrifugal, pulsatile, and new rotary/axial devices. Care of the patient on a ventricular assist device is multifaceted, involving pharmacologic or mechanical support of the right ventricle, management of systemic vascular resistance, and manipulation of the hematologic system to avoid bleeding or thrombosis. In addition, care of these patients involves support of all end organs and avoidance of infectious complications. Care of these patients is complex, requiring a highly integrated team for optimal outcome.

Perioperative management in pediatric heart transplantation from 1988 to 2001: anesthetic experience in a single center

Pediatric cardiac transplantation is currently an accepted option for end-stage heart disease and congenital cardiac malformations. This report focuses on the anesthetic perioperative management in 12 yr. From 1988 to 2001 we performed 90 heart transplantations in 88 children, infants and neonates. The pediatric heart transplant program of the children's heart center at our university hospital started in June 1988 with the transplantation of a 2-yr-old boy who was suffering from congenital heart disease. Since then, 88 transplants have been performed. We divided our patients into two groups. Group 1 ranged from 1988 to 1996 and Group 2 from 1997 to 2001. The patient characteristics have not significantly changed over the years in our institution. At the time of transplantation, mean age of the patients was 2.6 +/- 4.3 yr from the period of 1988-1996 and 2.5 +/- 4.1 yr from 1997 to 2001. Since 1988, 90 transplants (Tx) in 88 patients have been performed. Two patients needed re-Tx within 2 days after the initial operation because of primary graft failure. Indications for Tx were congenital heart disease (n = 67) and cardiomyopathy (n = 21). In the subgroup of the patients suffering from congenital heart disease there were 46 with the diagnosis of HLHS, followed by endocardial fibroelastosis (n = 7); the remaining 14 patients had other complex cardiac malformations and some underwent corrective palliative cardiac surgery before Tx. Sixty-three patients were younger than 1 yr of age and only five children were older than 10 yr. Twenty-three percent of the patients on the waiting list died before Tx was possible. The overall survival rate was 79% at 1 yr and 73% at 5 and 10 yr. Infants with HLHS had a lower probability of survival after 5 yr compared with other diagnosis (69% vs. 84%). Until now 21 patients have died after Tx. The duration of anesthesia, time of CPB and the age at the time of surgery decreased over the years. It is always a challenge for the anesthesiologist to treat these patients with pulmonary hypertension as one of the most critical risks in this group of patients. The preventive therapy with vasodilators as well as the availability of mechanical assist devices before and after heart transplantation reduces the effects of transitional pulmonary hypertension and prevents the development of post-operative right heart failure.