Pediatric ventricular assist devices: Bridge to a new era of perioperative care

Computational Evaluation of Cardiac Function in Children Supported with Heartware VAD, HeartMate 2 and HeartMate 3 Left Ventricular Assist Devices

Heart failure is one of the principal causes of morbidity and mortality in children. Treatment techniques may not work, and heart transplantation may be required as a result. The current state of donor-organ supply means that many patients cannot undergo transplantation. In these patients, ventricular assist devices (VADs) may be used to bridge the time until the transplantation. Continuous-flow VADs are increasingly being implanted to paediatric patients. The aim of this study was to evaluate cardiac function in children supported with Heartware HVAD, HeartMate2 and HeartMate3 devices using computational simulations. A lumped-parameter model simulating cardiac function in children around 12 years of age was used to simulate dilated cardiomyopathy and heart-pump support. The operating speeds in HVAD, HeartMate2 and HeartMate3 were selected as 2600 rpm, 8700 rpm and 5200 rpm constant speed, respectively, while the Lavare cycle and artificial-pulse modes were used to generate mean pump outputs at around 4.40 L/min and mean arterial pressures at around 82 mmHg in each device. Aortic pulse pressure was 11 mmHg, 14 mmHg and 6 mmHg under HVAD, HeartMate2 and HeartMate3 support, respectively. HVAD’s Lavare cycle and HeartMate3’s artificial pulse increased aortic pulse pressure to 15 mmHg and 20 mmHg. HeartMate3 with artificial-pulse mode may be more beneficial in reducing arterial-pulsatility-associated problems.

Neurosurgical intervention in children with ventricular assist devices: A single-center case series review

BACKGROUND

The incidence of neurological complications related to ventricular assist devices (VAD) remains high and includes life-threatening conditions such as intracranial hemorrhage or ischemic stroke. Although no definitive management guidelines exist, operative interventions may be required for major neurological injuries.

AIMS

This case series describes the perioperative management of children at a single center who underwent neurosurgical procedures for major intracranial bleeds or ischemic strokes while on VAD support.

METHODS

A database review identified all pediatric VAD patients who underwent a neurosurgical procedure for an intracranial hemorrhage or ischemic stroke from April 2014 to January 2020. Data regarding patient characteristics, preoperative medical management, intraoperative anesthetic management, and postoperative outcomes were collected using retrospective chart review.

RESULTS

Ninety VADs were implanted in 78 patients. Five neurosurgical interventions were performed: four for intracranial hemorrhages and one for an ischemic stroke. All four patients with hemorrhages were receiving anticoagulation at the time of their event and the three patients on warfarin received emergent reversal with prothrombin concentrate complex and vitamin K. Three patients also received pre-procedural platelet transfusions. Two of the five procedures were emergent bedside external ventricular drain placements, and three were surgical operations. All three patients who underwent operative procedures received invasive hemodynamic monitoring and were supported with a combination of inotropes and afterload reduction. One patient required a massive blood product transfusion. The two patients who underwent external ventricular drain placement had no further surgical interventions and died from the severity of their neurological injuries. All three patients who underwent operative procedures survived to transplantation and discharge home.

CONCLUSIONS

Perioperative concerns for the anesthesiologist include VAD hemodynamic management, bleeding, VAD thrombosis, and prevention of secondary brain injury. A systematic, multidisciplinary approach to management is paramount to attain favorable outcomes.

Cardiac Emergencies in Kids

Encountering a child with congenital heart disease after surgical palliation in the emergency department, specifically the single-ventricle or ventricular assist device, without a basic familiarity of these surgeries can be extremely anxiety provoking. Knowing what common conditions or complications may cause these children to visit the emergency department and how to stabilize will improve the chance for survival and is the premise for this article, regardless of practice setting.

A Review of Physiologic Considerations and Challenges in Pediatric Patients With Failing Single- Ventricle Physiology Undergoing Ventricular Assist Device Placement

Advances in surgical techniques and outpatient cardiac care have led to a growing population of pediatric patients surviving well into adulthood with previous single-ventricle palliation. Continued improvement in survival has resulted in subsequent increases in the number of patients with single-ventricle physiology listed for heart transplantations. Some of these patients require mechanical circulatory support as a bridge to transplantation, although establishing successful mechanical circulatory support in these complex patients remains challenging. Only limited published data exist describing the perioperative anesthetic management and key considerations dedicated to patients with failing single-ventricle physiology presenting for ventricular assist devices. This clinical review aims to provide a focused evaluation of the vital perioperative considerations encountered in this novel population.

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.

Complications in children with ventricular assist devices: systematic review and meta-analyses

Heart failure is a significant cause of mortality in children with cardiovascular diseases. Treatment of heart failure depends on patients' symptoms, age, and severity of their condition, with heart transplantation required when other treatments are unsuccessful. However, due to lack of fitting donor organs, many patients are left untreated, or their transplant is delayed. In these patients, ventricular assist devices (VADs) are used to bridge to heart transplant. However, VAD support presents various complications in patients. The aim of this study was to compile, review, and analyse the studies reporting risk factors and aetiologies of complications of VAD support in children. Random effect risk ratios (RR) with 95% confidence intervals were calculated to analyse relative risk of thrombosis (RR = 3.53 [1.04, 12.06] I² = 0% P = 0.04), neurological problems (RR = 0.95 [0.29, 3.15] I² = 53% P = 0.93), infection (RR = 0.31 [0.05, 2.03] I² = 86% P = 0.22), bleeding (RR = 2.57 [0.76, 8.66] I² = 0% P = 0.13), and mortality (RR = 2.20 [1.36, 3.55] I² = 0% P = 0.001) under pulsatile-flow and continuous-flow VAD support, relative risk of mortality (RR = 0.45 [0.15, 1.37] I² = 36% P = 0.16) under left VAD and biVAD support, relative risk of thrombosis (RR = 1.72 [0.46, 6.44] I² = 0% P = 0.42), infection (RR = 1.77 [0.10, 32.24] I² = 46% P = 0.70) and mortality (RR = 0.92 [0.14, 6.28] I² = 45% P = 0.93) in children with body surface area < 1.2 m² and > 1.2 m² under VAD support, relative risk of mortality in children supported with VAD and diagnosed with cardiomyopathy and congenital heart diseases (RR = 1.31 [0.10, 16.61] I² = 73% P = 0.84), and cardiomyopathy and myocarditis (RR = 0.91 [0.13, 6.24] I² = 58% P = 0.92). Meta-analyses results show that further research is necessary to reduce complications under VAD support.

Anesthesia in Pediatric Patients With Congenital Heart Disease Undergoing Noncardiac Surgery: Defining the Risk

The incidence of moderate to severe congenital heart disease (CHD) in the United States is estimated to be 6 per 1,000 live-born, full-term infants. Recent advances in pediatric cardiology, surgery, and critical care have improved significantly the survival rates of patients with CHD leading to an increase in prevalence in both children and adults. Children with CHD significant enough to require cardiac surgery frequently also undergo noncardiac surgical procedures. With this increased demand for procedures that require anesthesia, all anesthesiologists, and more specifically, pediatric anesthesiologists will encounter patients with repaired or unrepaired CHD and other cardiac diseases in their practice. They often are faced with the question, "Is this patient too high risk for anesthesia?" The objective of this literature review is to provide a greater understanding of patients at high risk and to quantify the risk for patients, their families, and clinicians. In addition, specific high-risk lesions (single ventricle, Williams-Beuren syndrome, pulmonary hypertension, cardiomyopathies, and ventricular assist devices) are described.