Preliminary Single Center North American Experience With The Berlin Heart Pediatric EXCOR Device

The use of mechanical assist devices in the pediatric population

The last two decades have witnessed an expansion in the devices, support strategies, and outcomes for pediatric patients who require mechanical circulatory support. The use of large registries that house data on these devices and the development of shared learning networks have provided clinicians with the ability to critically assess outcomes for emerging and existing technology. The purpose of this review is to provide the reader with perspective on the most contemporary devices utilized for pediatric mechanical circulatory support. It will examine existing support strategies and the most contemporary outcomes regarding these devices including those in high risk patients.

Approach to a Child with Congestive Heart Failure

Pediatric heart failure (PHF) is an important cause of mortality and morbidity. Whereas ischemic heart disease is the most important cause of heart failure in adults, congenital heart diseases (CHD) and cardiomyopathies are important etiologies of PHF. Management of PHF also differs from that of adults. Here authors have reviewed the literature on PHF with respect to etiology, symptoms, investigations and treatment strategies.

Experience with Temporary Centrifugal Pump Bi-ventricular Assist Device for Pediatric Acute Heart Failure: Comparison with ECMO

Though ventricular assist devices (VADs) are an important treatment option for acute heart failure, an extracorporeal membrane oxygenator (ECMO) is usually used in pediatric patients for several reasons. However, a temporary centrifugal pump-based Bi-VAD might have clinical advantages versus ECMO or implantable VADs. From January 2000 to July 2018, we retrospectively reviewed 36 pediatric patients who required mechanical circulatory support (MCS) for acute heart failure. Cases with postoperative MCS were excluded. Since 2016, we have tried to immediately add a right VAD rather than ECMO, when the patients begin to present features of right heart failure after left VAD support started in cases that the patients' respiratory function did not require an oxygenator. Original diagnoses included dilated cardiomyopathy (n = 18), myocarditis (n = 11), and others (n = 7). Eleven patients were supported by Bi-VAD, and 25 patients were supported by ECMO; of these. Four patients were successfully weaned from VAD, and 10 patients were weaned from ECMO. Eleven patients underwent heart transplantation. Overall, we have 15 (41.7%) early mortalities. There were no significant differences in early mortality, morbidity, and weaning rate between the Bi-VAD group and the ECMO group. During the support, patients with Bi-VADs significantly required fewer platelets and showed less hemolysis than ECMO patients. Patients with myocarditis were successfully weaned from Bi-VAD support and bridged to transplantation thereafter. A temporary centrifugal pump-based Bi-VAD was clinically comparable to ECMO for pediatric patients with acceptable pulmonary function.

The Evolution of a Pediatric Ventricular Assist Device Program: The Boston Children's Hospital Experience

Mechanical circulatory support in the form of ventricular assist devices (VADs) in children has undergone rapid growth in the last decade. With expansion of device options available for larger children and adolescents, the field of outpatient VAD support has flourished, with many programs unprepared for the clinical, programmatic, and administrative responsibilities. From preimplantation VAD evaluation and patient education to postimplant VAD management, the VAD program, staffed with an interdisciplinary team, is essential to providing safe, effective, and sustainable care for a new technology in an exceedingly complex patient population. Herein, this paper describes the Boston Children's Hospital VAD experience over a decade and important lessons learned from developing a pediatric program focusing on a high-risk but low-volume population. We highlight the paramount role of the VAD coordinator, clinical infrastructure requirements, as well as innovation in care spanning inpatient and outpatient VAD supports at Boston Children's Hospital.

Early Biventricular Assist Device Use in Children: A Single-Center Review of 31 Patients

Biventricular assist device (BiVAD) support is considered a risk factor for worse outcomes compared with left ventricular assist device (LVAD) alone for children with end-stage heart failure. It remains unclear whether this is because of the morbidity associated with a second device or the underlying disease severity. We aimed to show that early BiVAD support can result in good survival by analyzing our prospectively collected database for all pediatric patients who underwent BiVAD implantation. From 2005 to 2009, BiVADs were used exclusively. From 2010 to 2014, LVAD alone was considered, maintaining a low threshold for BiVAD support. All BiVADs were pulsatile devices. Thirty-one patients with median age of 3.5 years received BiVAD support. Diagnoses included dilated cardiomyopathy in 17 (55%), myocarditis in 6 (19%), and congenital heart disease in 3 (10%). Survival to transplant was achieved in 27 (87%) with a median duration of 41 days (interquartile range, 15-69). Adverse event rates (per 100 days of support) were bleeding at 0.52, infection at 1.17, and central nervous system dysfunction at 0.78. Of those who survived to transplant, 26 (96%) remain alive with a median follow-up of 55 months. These results show that BiVAD support can bridge patients to transplant with excellent long-term survival.

Biventricular mechanical support devices--clinical perspectives

Cardiac transplantation remains the optimal treatment for end stage heart failure in selected patients. However, the shortage of donor hearts, rigorous eligibility criteria and long waiting lists have increased the demand for alternative treatment strategies such as mechanical circulatory support. While many patients are adequately supported with left ventricular assist devices, frequently there is right heart failure or involvement of the right ventricle, requiring biventricular support. Pulsatile flow biventricular devices and total artificial hearts approved for temporary biventricular support have limitations including size, high rates of adverse events and restricted mobility which makes them unsuitable for long term support. A number of centres have reported dual continuous flow left ventricular assist devices as a means of supporting the left and right heart. This review will summarise the literature on the outcomes and complications from current biventricular support devices and assess the role of dual continuous flow VAD therapy, and the new continuous flow total heart replacement devices.

Paediatric mechanical circulatory support with Berlin Heart EXCOR: development and outcome of a 23-year experience

This paper reviews the development and establishment of the Berlin Heart EXCOR® (BHE®) as a paediatric mechanical circulatory support and reports our entire experience with regard to indications, timing of implantation and explantation and outcome. The Berlin group reported the first successful paediatric bridge to transplantation using a pulsatile pneumatic paracorporeal biventricular assist device, the BHE®, in 1990 in an 8-year-old boy with end-stage heart failure and coarctation of the aorta. This experience prompted them to develop miniaturized pump systems for children through the company Berlin Heart Mediproduct GmbH. The development and production of BHE® to support paediatric patients with heart failure then began. Between 1990 and 2013, the BHE® has been implanted in 122 patients (median age 8.64 years, range 3 days to 17 years) with heart failure, who were inotrope-dependent or switched from extracorporeal membrane oxygenation support or had postcardiotomy low-output syndrome. Thirty-five patients were <1 year old (median 125 days). The aetiology of heart failure included cardiomyopathy in 56 (median age 9.14 years), fulminant myocarditis in 17 (median age 8.2 years), end-stage congenital heart disease in 18 (median age 6.4 years), postcardiotomy heart failure (after correction of congenital heart disease) in 28 (median age 9.6 years) and transplant graft failure in 3 (median age 12.5 years). The overall median duration of implantation was 63.6 (range 1-841) days. Fifty-six children eventually underwent orthotopic heart transplantation. Eighteen patients had myocardial recovery and were weaned successfully. They had entirely normal cardiac function after a range of 4-10 years after surgery. At the time of this report, five patients were still on support, with a duration of 354-369 days. Forty-three patients died on the system from loss of peripheral circulatory resistance, multiorgan damage, sepsis or haemorrhagic or thrombotic complications. Re-exploration because of bleeding was necessary in 22 patients. Pump exchange because of thrombus formation in the valves was necessary 35 times. With the introduction of a modified anticoagulation regimen in 2000, the pump exchange rate has decreased. The BHE® can reliably support the circulation at any age for long periods with good results. It is now an established treatment for children with heart failure of any aetiology.

Hemorrhage requiring surgical intervention among children on pulsatile ventricular assist device support

Bleeding complications are a source of morbidity after Berlin EXCOR VAD implantation yet remain poorly characterized. We evaluated our experience to describe the bleeding complications among pediatric VAD recipients. We hypothesized that those with bleeding requiring exploration had abnormal coagulation profile compared with those without bleeding. The retrospective study included 43 consecutive patients with end-stage heart failure supported on pediatric mechanical cardiac support as a bridge to transplantation. Day-/event-based analysis on factors below associated with (i) bleeding and (ii) bleeding in next 48 h. Cases with bleeding were compared with day-matched patients without bleeding complications. Among 43 subjects bleeding occurred in 47% of cases, which necessitated exploration or chest tube placement. Twenty of 34 interventions for bleeding occurred in the first seven post-operative days. No differences in coagulation parameters or use of antiplatelet agents were noted among those who had bleeding vs. those who did not. Our results indicate that (i) re-bleeding requiring re-exploration was common, (ii) most of the bleeding occurred early post-implantation, (iii) there were no differences in coagulation parameters or the use of antiplatelet agents within 48 h of bleeding compared with those who did not bleed on each successive post-operative day.

Recent advances in computational methodology for simulation of mechanical circulatory assist devices

Ventricular assist devices (VADs) provide mechanical circulatory support to offload the work of one or both ventricles during heart failure. They are used in the clinical setting as destination therapy, as bridge to transplant, or more recently as bridge to recovery to allow for myocardial remodeling. Recent developments in computational simulation allow for detailed assessment of VAD hemodynamics for device design and optimization for both children and adults. Here, we provide a focused review of the recent literature on finite element methods and optimization for VAD simulations. As VAD designs typically fall into two categories, pulsatile and continuous flow devices, we separately address computational challenges of both types of designs, and the interaction with the circulatory system with three representative case studies. In particular, we focus on recent advancements in finite element methodology that have increased the fidelity of VAD simulations. We outline key challenges, which extend to the incorporation of biological response such as thrombosis and hemolysis, as well as shape optimization methods and challenges in computational methodology.

Options for the failing ventricle in pediatric heart disease

The management of the pediatric patient with the failing ventricle poses its own therapeutic challenges, not least because patient size limits options available. Once medical management has hit its ceiling, attention is turned to surgical options for mechanical support. The approach to these options has to bear in mind that there may be many potential causes for pump failure, and that these occur often in the context of pulmonary hypertension and poor gas exchange. Although extracorporeal life support has been the mainstay of treatment for acute heart failure, in the last decade, attention has been focusing on longer-term options to bridge to recovery or eventual transplant. Added to this are more novel applications of ventricular assist devices, notable in the management of the failing Fontan circulation where there are no perfect solutions. There is growing interest in the use of such devices to power this delicate circulation and extend the functional capacity of patients without resorting to transplantation. In this review article, we explore the role each of these surgical modalities has to play in the management of the child with acute and chronic heart failure, and explore the recent developments in the rapidly growing field of pediatric ventricular assist.

Berlin Heart EXCOR pediatric ventricular assist device for bridge to heart transplantation in US children

BACKGROUND

Recent data suggest that the Berlin Heart EXCOR Pediatric ventricular assist device is superior to extracorporeal membrane oxygenation for bridge to heart transplantation. Published data are limited to 1 in 4 children who received the device as part of the US clinical trial. We analyzed outcomes for all US children who received the EXCOR to characterize device outcomes in an unselected cohort and to identify risk factors for mortality to facilitate patient selection.

METHODS AND RESULTS

This multicenter, prospective cohort study involved all children implanted with the Berlin Heart EXCOR Pediatric ventricular assist device at 47 centers from May 2007 through December 2010. Multiphase nonproportional hazards modeling was used to identify risk factors for early (<2 months) and late mortality. Of 204 children supported with the EXCOR, the median duration of support was 40 days (range, 1-435 days). Survival at 12 months was 75%, including 64% who reached transplantation, 6% who recovered, and 5% who were alive on the device. Multivariable analysis identified lower weight, biventricular assist device support, and elevated bilirubin as risk factors for early mortality and bilirubin extremes and renal dysfunction as risk factors for late mortality. Neurological dysfunction occurred in 29% and was the leading cause of death.

CONCLUSIONS

Use of the Berlin Heart EXCOR has risen dramatically over the past decade. The EXCOR has emerged as a new treatment standard in the United States for pediatric bridge to transplantation. Three-quarters of children survived to transplantation or recovery; an important fraction experienced neurological dysfunction. Smaller patient size, renal dysfunction, hepatic dysfunction, and biventricular assist device use were associated with mortality, whereas extracorporeal membrane oxygenation before implantation and congenital heart disease were not.

Outcome of pediatric heart transplantation recipients treated with ventricular assist device

This study was conducted to evaluate the long-term prognosis of pediatric HTx patients treated with VAD before transplantation. The clinical data of six patients bridged to HTx with Berlin Heart EXCOR pediatric device were analyzed retrospectively. Information about graft function, CA results, and EMB findings as well as appearance DSA was collected. Also, information about growth and cognitive function was analyzed. These findings were compared with age-, gender-, and diagnosis-matched HTx patients. During the median follow-up time of four and half yr after HTx, the prognosis including graft function, number of rejection episodes, and incidence of coronary artery vasculopathy, growth and cognitive development did not differ between VAD-bridged HTx patients compared with control patients. In both groups, one patient developed positive DSA titer after HTx. Our single-center experience suggests that the prognosis of pediatric HTx patients treated with VAD before transplantation is not inferior to that of other HTx patients.

Mechanical circulatory support for end-stage heart failure in repaired and palliated congenital heart disease

Approximately one in one hundred children is born with congenital heart disease. Most can be managed with corrective or palliative surgery but a small group will develop severe heart failure, leaving cardiac transplantation as the ultimate treatment option. Unfortunately, due to the inadequate number of available donor organs, only a small number of patients can benefit from this therapy, and mortality remains high for pediatric patients awaiting heart transplantation, especially compared to adults. The purpose of this review is to describe the potential role of mechanical circulatory support in this context and to review current experience. For patients with congenital heart disease, ventricular assist devices are most commonly used as a bridge to cardiac transplantation, an application which has been shown to have several important advantages over medical therapy alone or support with extracorporeal membrane oxygenation, including improved survival to transplant, less exposure to blood products with less immune sensitization, and improved organ function. While these devices may improve wait list mortality, the chronic shortage of donor organs for children is likely to remain a problem into the foreseeable future. Therefore, there is great interest in the development of mechanical ventricular assist devices as potential destination therapy for congenital heart disease patients with end-stage heart failure. This review first discusses the experience with the currently available ventricular assist devices in children with congenital heart disease, and then follows to discuss what devices are under development and may reach the bedside soon.

Pediatric outcomes after extracorporeal membrane oxygenation for cardiac disease and for cardiac arrest: a review

We reviewed reported survival and neurological outcomes, and predictors of these outcomes for pediatric cardiac extracorporeal membrane oxygenation (ECMO) and extracorporeal cardiopulmonary resuscitation (ECPR). We searched PubMed from 2000 to April 2011. Cumulative survival after cardiac ECMO in children was 788/1755 (45%); renal dysfunction, dialysis, neurologic complication, lactate, and ECMO duration consistently predicted this outcome, whereas single ventricle and ECPR did not. Neurological outcomes after cardiac ECMO were based on poorly described telephone questions in two studies for 47 patients with 51% significantly impaired and detailed follow-up testing for 42 patients in three studies with mental delay in 38% and mental score >85 (average or above) in 33%. Cumulative survival after ECPR in children was 371/762 (49%); noncardiac disease, renal dysfunction, neurologic complication, and pH on extracorporeal life support consistently predicted this outcome, whereas duration of CPR did not. Neurological outcomes after ECPR were based predominantly on the pediatric cerebral performance category (PCPC) score by chart review, with 161/181 (79%) having PCPC <2. No study reported detailed follow-up testing for survivors of ECPR. Survival outcomes of most cardiac subgroups were similar, except for concerning mortality in cavopulmonary connection patients. Priority areas for study include identification of potentially modifiable predictors of long-term outcomes.

Neurodevelopmental outcomes in children with congenital heart disease: evaluation and management: a scientific statement from the American Heart Association

BACKGROUND

The goal of this statement was to review the available literature on surveillance, screening, evaluation, and management strategies and put forward a scientific statement that would comprehensively review the literature and create recommendations to optimize neurodevelopmental outcome in the pediatric congenital heart disease (CHD) population.

METHODS AND RESULTS

A writing group appointed by the American Heart Association and American Academy of Pediatrics reviewed the available literature addressing developmental disorder and disability and developmental delay in the CHD population, with specific attention given to surveillance, screening, evaluation, and management strategies. MEDLINE and Google Scholar database searches from 1966 to 2011 were performed for English-language articles cross-referencing CHD with pertinent search terms. The reference lists of identified articles were also searched. The American College of Cardiology/American Heart Association classification of recommendations and levels of evidence for practice guidelines were used. A management algorithm was devised that stratified children with CHD on the basis of established risk factors. For those deemed to be at high risk for developmental disorder or disabilities or for developmental delay, formal, periodic developmental and medical evaluations are recommended. A CHD algorithm for surveillance, screening, evaluation, reevaluation, and management of developmental disorder or disability has been constructed to serve as a supplement to the 2006 American Academy of Pediatrics statement on developmental surveillance and screening. The proposed algorithm is designed to be carried out within the context of the medical home. This scientific statement is meant for medical providers within the medical home who care for patients with CHD.

CONCLUSIONS

Children with CHD are at increased risk of developmental disorder or disabilities or developmental delay. Periodic developmental surveillance, screening, evaluation, and reevaluation throughout childhood may enhance identification of significant deficits, allowing for appropriate therapies and education to enhance later academic, behavioral, psychosocial, and adaptive functioning.

Antithrombotic therapy in neonates and children: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines

BACKGROUND

Neonates and children differ from adults in physiology, pharmacologic responses to drugs, epidemiology, and long-term consequences of thrombosis. This guideline addresses optimal strategies for the management of thrombosis in neonates and children.

METHODS

The methods of this guideline follow those described in the Methodology for the Development of Antithrombotic Therapy and Prevention of Thrombosis Guidelines: Antithrombotic Therapy and Prevention of Thrombosis, 9th ed: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines.

RESULTS

We suggest that where possible, pediatric hematologists with experience in thromboembolism manage pediatric patients with thromboembolism (Grade 2C). When this is not possible, we suggest a combination of a neonatologist/pediatrician and adult hematologist supported by consultation with an experienced pediatric hematologist (Grade 2C). We suggest that therapeutic unfractionated heparin in children is titrated to achieve a target anti-Xa range of 0.35 to 0.7 units/mL or an activated partial thromboplastin time range that correlates to this anti-Xa range or to a protamine titration range of 0.2 to 0.4 units/mL (Grade 2C). For neonates and children receiving either daily or bid therapeutic low-molecular-weight heparin, we suggest that the drug be monitored to a target range of 0.5 to 1.0 units/mL in a sample taken 4 to 6 h after subcutaneous injection or, alternatively, 0.5 to 0.8 units/mL in a sample taken 2 to 6 h after subcutaneous injection (Grade 2C).

CONCLUSIONS

The evidence supporting most recommendations for antithrombotic therapy in neonates and children remains weak. Studies addressing appropriate drug target ranges and monitoring requirements are urgently required in addition to site- and clinical situation-specific thrombosis management strategies.

Ventricular assist device support in children and adolescents with heart failure: the Children's Medical Center of Dallas experience

Children with heart failure unresponsive to medical therapy are left with few options for survival. Ventricular assist devices (VADs) are life-saving options for such patients, allowing for bridge to transplantation or cardiac recovery. Retrospective review of cases from May 2006 to October 2010 was undertaken. Fourteen patients underwent implantation of VADs for refractory heart failure. Mean age was 9 years (range 1-17 years), and weight was 41 kg (range 9.7-71 kg). Indications for support: end-stage cardiomyopathy (n = 8), myocarditis (n = 3), univentricular failure (n = 2), and congenital heart disease/postcardiotomy (n = 1). Level of limitation at time of implant included critical cardiogenic shock in six (43%) and progressive decline in eight (57%). Extracorporeal membrane oxygenation was used as a bridge to VAD in five (36%) patients. Preimplant variables: 86% of patients requiring mechanical ventilation (mean 10.3 days), hyperbilirubinemia in 75%, and acute renal insufficiency in 79%. Device selection was systemic VAD in 11 (79%) and biventricular assist device in three (21%). Berlin Heart EXCOR was used in eight patients, while six patients received a Thoratec implantable VAD or paracorporeal VAD. Mean duration of support was 68 days (range 8-363 days). Overall survival was 79%. Ten patients (71%) were successfully bridged to transplantation, three (21%) died while on a device, one remains on support, and no patients were weaned from VAD. Children supported for single ventricle heart failure had a 50% survival with none currently bridged to transplantation. Complications included bleeding requiring reoperation in 21% (n = 3), stroke in 29% (n = 4), and driveline infections in 7% (n = 1). In two patients, a total of six pump exchanges were performed for thrombus formation. Survival for pediatric patients of all ages is excellent using current device technology with a majority of patients being successfully bridged to transplantation. Morbidity is acceptably low considering the severity of illness. Significant challenges exist with long-term extracorporeal support due to lack of donor availability and the high incidence of preformed alloantibodies especially in the failing single ventricle.

A method for anticoagulation of children on mechanical circulatory support

Anticoagulation of children on mechanical circulatory support presents a challenge. We implanted 28 devices in children and infants using a consistent anticoagulation protocol. We performed a retrospective review of all children implanted in our program with mechanical assist devices since 1997. Heparin, dipyridamole, and aspirin were used for anticoagulation and antiaggregation. Coagulation monitoring included thromboelastography (TEG), platelet aggregration studies, international normalized ratio, partial thromboplastin time, and platelet count. Twenty-eight children, ages 1 month to 16 years (mean 5.3; median 2.4 years), were implanted for 3-107 days (mean 27; median 17). Eighteen received left ventricular assist devices, seven received biventricular assist devices, and three received total artificial hearts. Adverse events during the 720 days of device support included the following: six (21%) reoperations for bleeding; seven strokes (25%): two fatal, two with a mild residual deficit, and three without deficit; and three (11%) visceral emboli: two fatal and one nonfatal. There were eight deaths (29%). Causes of death were embolic (four), graft failure post-transplantation (one), preimplant anoxic brain damage (two), and postexplant heart failure (one). 24/28 (86%) survived to transplantation or weaning from device and 20/28 (71%) were discharged from the hospital, 10 after transplantation and 10 after native heart recovery. All 20 early survivors survived long term. We describe an anticoagulation protocol based upon TEG and platelet aggregation studies and using heparin, aspirin, and dipyridamole. Adequate anticoagulation is more difficult in children. However, 71% of the patients in our study survived long term.

Pediatric Ventricular Assist Devices: The Future (as of 2011)

In the last decade, there have been enormous advances in the field of pediatric-specific mechanical circulatory support. In the past, small children requiring bridge to transplant or recovery were limited to extracorporeal membrane oxygenation. Now, in various stages of development, there are several devices that offer the promise of the same quality of support enjoyed by older teenagers and adolescents, with the potential to substantially reduce transplant waiting list mortality and optimize transplant outcomes. Advances have been driven by both industry and, for the first time, by funding from the US National Institutes of Health.

Clinical experience with Berlin Heart Excor in pediatric patients in Argentina: 1373 days of cardiac support

The objective of this study was to describe our experience (1373 days of support) with the Berlin Heart Excor (BH) ventricular-assist device (VAD) as bridging to cardiac transplantation in pediatric patients with end-stage cardiomyopathy. This study involved a retrospective observational cohort. Records of patients supported with the BH VAD were reviewed. Data regarding age, sex, weight, diagnosis, preoperative condition, single versus biventricular support, morbidity, and mortality were collected. Criteria for single versus biventricular support and intensive care unit management were registered. The procedure was approved by our Institutional Ethics Committee, and informed consent was obtained. Between March 2006 and March 2010, 12 patients with diagnosis of dilated (n = 10) and restrictive (n = 2) cardiomyopathy were supported. Median age was 56.6 months (range 20.1-165.9); mean weight was 18.3 kg (range 8.5-45); and nine patients were female. Every patient presented with severe heart failure refractory to pharmacological therapy. Biventricular support was necessary in four patients. Nine patients underwent heart transplantation. No child was weaned off the BH VAD because of myocardial recovery. Mean length of support was 73 days (range 3-331), and the total number of days of support was 1373. Three patients had fatal complications: 2 had thrombo-hemorrhagic stroke leading to brain death, and one had refractory vasoplegic shock. The BH VAD is a useful and reasonable safe device for cardiac transplantation bridging in children with end-stage heart failure. Team experience resulted in less morbidity and mortality, and time for implantation, surgical procedure, anticoagulation monitoring, and patient care improved.

Perioperative management of pediatric patients on mechanical cardiac support

The population of children with end-stage heart failure requiring mechanical circulatory support is growing. These children present for diagnostic imaging studies, various interventions and noncardiac surgical procedures that require anesthetic care. This article is a review of the population demographics of children on mechanical cardiac support, the alternative devices available, and the important concepts for safe perioperative management of these patients. The discussion will be limited to devices for short- and long-term cardiac support, excluding extracorporeal membrane oxygenation (ECMO) for respiratory support.

Factors associated with in-hospital mortality in infants undergoing heart transplantation in the United States

OBJECTIVE

Infants undergoing heart transplantation have the highest early posttransplant mortality of any age group. We sought to determine the pretransplantation factors associated with in-hospital mortality in transplanted infants in the current era.

METHODS

All infants under 12 months of age who underwent primary heart transplantation during a recent 10-year period (1999-2009) in the United States were identified using the Organ Procurement and Transplant Network database. Multivariable logistic regression was used to identify independent pretransplantation factors associated with in-hospital mortality.

RESULTS

Of 730 infants in the study (median age 3.8 months), 462 (63%) had congenital heart disease, 282 (39%) were supported by a ventilator, 94 (13%) with extracorporeal membrane oxygenation, and 22 (3%) with a ventricular assist device at the time of transplantation. Overall, 82 (11.2%) infants died before their initial hospital discharge. In adjusted analysis, in-hospital mortality was associated with repaired congenital heart disease (odds ratio [OR], 3.6; 95% confidence interval [CI], 1.8, 7.2), unrepaired congenital heart disease not on prostaglandin E (OR, 2.8; CI, 1.3, 6.1), extracorporeal membrane oxygenator support (OR, 6.1; CI, 2.8, 13.4), ventilator support (OR, 4.4; CI, 2.3, 8.3), creatinine clearance less than 40 mL·min(-1)·1.73 m(-2) (OR, 3.1; CI, 1.7, 5.3), and dialysis (OR, 6.2; CI, 2.1, 18.3) at transplantation.

CONCLUSIONS

One in 9 infants undergoing heart transplantation dies before hospital discharge. Pretranplantation factors associated with early mortality include congenital heart disease, extracorporeal membrane oxygenator support, mechanical ventilation, and renal failure. Risk stratification for early posttransplant mortality among infants listed for heart transplantation may improve decision-making for transplant eligibility, organ allocation, and posttransplant interventions to reduce mortality.

Implantation of a Berlin Heart ventricular assist device

Until recently the only mode of mechanical circulatory support available in North America for use as bridge to cardiac transplantation in small children was extra-corporeal membrane oxygenation. However, since 2005 the Berlin Heart pediatric ventricular assist device has been increasingly widely used for both biventricular and left ventricular support. The device is available in a wide range of sizes, allowing its use in children as small as 5 kg and as large as 60 kg. It has been applied in end-stage heart failure of both structural/congenital and myopathic etiology (including myocarditis). In the article the technique for implantation of the device will be described, with focus on certain details that facilitate safe implantation and subsequent explantation, whether in the setting of a heart transplant operation or in the setting of recovery of native heart function.

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.

Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS)-defined morbidity and mortality associated with pediatric ventricular assist device support at a single US center: the Stanford experience

BACKGROUND

The use of ventricular assist devices (VADs) to bridge pediatric patients to heart transplantation has increased dramatically over the last 15 years. In this report, we present the largest US single-center report of pediatric VAD use to date. We present detailed descriptions of morbidity and mortality associated with VAD support, using standard Interagency Registry for Mechanically Assisted Circulatory Support (INTERMACS) criteria for pediatrics to facilitate the comparison of these results to other studies.

METHODS AND RESULTS

We retrospectively identified 25 patients younger than 18 years with 27 episodes of mechanical circulatory support using VADs as bridge to heart transplantation from January 1998 to December 2007. Survival to transplant for the entire cohort was 74%. The most common major morbidities, as defined by INTERMACS criteria for a pediatric population, were respiratory failure, major localized infections, major bleeding events, hepatic dysfunction, and right heart failure. Major neurological events occurred in 48% of the study population. The median time to the first occurrence of an adverse event was less than 14 days for respiratory failure, right heart failure, major localized infection, and major bleeding. Patients who died before transplantation had significantly more adverse events per day of support than did those who were successfully transplanted. Episodes of major bleeding, tamponade, acute renal failure, respiratory failure, and right heart failure were all associated with increased risk of mortality.

CONCLUSIONS

INTERMACS criteria can be successfully used to analyze pediatric VAD outcomes. These data serve as a baseline for future studies of VAD support in children and indicate good survival rates but considerable morbidity.

Anesthesia for noncardiac procedures for children with a Berlin Heart EXCOR Pediatric Ventricular Assist Device: a case series

OBJECTIVES

To report our experience of providing anesthesia for noncardiac procedures in children with in situ Berlin Heart EXCOR Pediatric ventricular assist devices and to suggest principles of anesthetic management.

BACKGROUND

With the initiation of the first North American training and support center for Berlin Heart at our institution in 2006, we have been asked to provide anesthesia for noncardiac procedures to these children. No current anesthetic approach to these children has been reported.

METHODS/MATERIALS

Anesthetic records for all noncardiac procedures for children with Berlin Heart between August 2006 and February 2009 in a tertiary care pediatric hospital were retrospectively reviewed. Charts were reviewed for demographic and clinical data, perioperative management, and occurrence of hypotension.

RESULTS

Twenty-nine procedures were performed on 11 patients. Hypotension was a common occurrence with all anesthetic induction and maintenance agents even at low doses. Ketamine induction, however, was less likely to produce hypotension, odds ratio for hypotension 0.1333 (95% confidence range 0.021-0.856). Hypotension was responsive to fluid bolus (60%) and alpha-receptor agonists (100%). Preoperative stability and presence of biventricular ventricular assist device (BiVAD) did not predict intraoperative hemodynamic course.

CONCLUSIONS

Unlike patients with other ventricular assist devices, these children do not tolerate reductions in systemic vascular resistance (SVR) because of the relatively fixed cardiac output of this device. Agents that reduce SVR should be avoided where possible. Preoperative stability is not predictive. Fluids and alpha-agonists should be first-line response to hypotension in this population. Further study of this unusual population is warranted to further delineate best anesthetic practice.

Extracorporeal membrane oxygenation for the support of infants, children, and young adults with acute myocarditis: a review of the Extracorporeal Life Support Organization registry

OBJECTIVE

To describe survival outcomes for pediatric patients supported with extracorporeal membrane oxygenation for severe myocarditis and identify risk factors for in-hospital mortality.

DESIGN

Retrospective review of Extracorporeal Life Support Organization registry database.

SETTING

Data reported to Extracorporeal Life Support Organization from 116 extracorporeal membrane oxygenation centers.

PATIENTS

Patients < or = 18 yrs of age supported with extracorporeal membrane oxygenation for myocarditis during 1995 to 2006.

INTERVENTIONS

None.

MEASUREMENTS AND MAIN RESULTS

Of 19,348 reported pediatric extracorporeal membrane oxygenation uses from 1995 to 2006, 260 runs were for 255 patients with a diagnosis of myocarditis (1.3%). Survival to hospital discharge was 61%. Seven patients (3%) underwent heart transplantation and six patients survived to discharge. Of 100 patients not surviving to hospital discharge, extracorporeal membrane oxygenation support was withdrawn in 70 (70%) with multiple organ failure as the indication in 58 (83%) patients. In a multivariable model, female gender (adjusted odds ratio, 2.3, 95% confidence interval, 1.3-4.2), arrhythmia on extracorporeal membrane oxygenation (adjusted odds ratio, 2.7, 95% confidence interval, 1.5-5.1), and renal failure requiring dialysis (adjusted odds ratio, 5.1, 95% confidence interval, 2.3-11.4) were associated with increased odds of in-hospital mortality.

CONCLUSION

Extracorporeal membrane oxygenation is a valuable tool to rescue children with severe cardiorespiratory compromise related to myocarditis. Female gender, arrhythmia on extracorporeal membrane oxygenation, and need for dialysis during extracorporeal membrane oxygenation were associated with increased mortality.