Use of Extracorporeal Membrane Oxygenation After Congenital Heart Disease Repair: A Systematic Review and Meta-Analysis

Heart failure in children and adolescents: an update on diagnostic approaches and management

Cardiac failure is a clinical syndrome that may develop in children owing to cardiac dysfunction or underlying structural heart diseases. Considering the differences in diagnostic and therapeutic approaches for pediatric heart failure (PHF) and adult heart failure, we have reviewed the current literature on PHF. Relevant studies were extracted from MEDLINE/PubMed, Google Scholar, and Clinical Trial Registries using the terms "pediatric heart failure" or "heart failure in children" and "management" or "decongestive therapy." Recent advances in diagnostic approaches, such as cardiac magnetic resonance, speckle-tracking echocardiography, tissue Doppler imaging, and molecular diagnostic techniques, have increased our under -standing of PHF. It is imperative that clinicians evaluate the interrelated factors responsible for the develop ment of PHF, including myocardial function, pulmonary and systemic blood flow, heart rhythm, valve function, and nutritional status. Although recent advances have demon strated the efficacy of many new drugs in adult heart failure trials, it cannot be concluded that these drugs will show similar efficacy in children, considering the heterogeneous nature of the underlying mechanisms and variable pharmacody-namics and pharmacokinetics. Therefore, the underlying pathophysiology of PHF and the mechanisms of action of different drugs should be considered when selecting appropriate therapies. Further trials are needed to establi sh the efficacy and safety of these drugs, and a combined mul-ti disciplinary strategy will help enhance PHF outcomes.

Early outcomes of moderate-to-high-risk pediatric congenital cardiac surgery and predictors of extracorporeal circulatory life support requirement

Background

Cardiopulmonary failure refractory to medical management after moderate-to-high-risk congenital cardiac surgery may necessitate mechanical support with veno-arterial extracorporeal membrane oxygenation (ECMO). On the extreme, ECMO can also be initiated in the setting of cardiac arrest (extracorporeal cardiopulmonary resuscitation, ECPR) unresponsive to conventional resuscitative measures.

Methods

This was a single-center retrospective cohort study of patients (n = 510) aged <3 years old who underwent cardiac surgery with cardiopulmonary bypass with a RACHS-1 score ≥3 between 2011 and 2014. Perioperative factors were reviewed to identify predictors of ECMO initiation and mortality in the operating room (OR) and the intensive care unit (ICU).

Results

A total of 510 patients with a mean surgical age of 10.0 ± 13.4 months were included. Among them, 21 (4%) patients received postoperative ECMO-12 were initiated in the OR and 9 in the ICU. ECMO cannulation was associated with cardiopulmonary bypass duration, aortopulmonary shunt, residual severe mitral regurgitation, vaso-inotropic score, and postprocedural lactate (p < 0.001). Of the 32 (6%) total deaths, 7 (22%) were ECMO patients-4 were elective OR cannulations and 3 were ICU ECPR. Prematurity [hazard ratio (HR): 2.61, p < 0.01), Norwood or Damus-Kaye-Stansel procedure (HR: 4.29, p < 0.001), postoperative left ventricular dysfunction (HR: 5.10, p = 0.01), residual severe tricuspid regurgitation (HR: 6.06, p < 0.001), and postoperative ECMO (ECPR: HR: 15.42, p < 0.001 vs. elective: HR: 5.26, p = 0.01) were associated with mortality. The two patients who were electively cannulated in the ICU survived.

Discussion

Although uncommon, postoperative ECMO in children after congenital cardiac surgery is associated with high mortality, especially in cases of ECPR. Patients with long cardiopulmonary bypass time, residual cardiac lesions, or increased vaso-inotropic requirement are at higher risk of receiving ECMO. Pre-emptive or early ECMO initiation before deterioration into cardiac arrest may improve survival.

National In-Hospital Outcomes of Mechanical Mitral Valve Replacement in the Pediatric Population

Background: National data about the outcomes of children undergoing mechanical mitral valve replacement (m-MVR) are scarce. Methods: A retrospective review of hospitalizations from the Kids' Inpatient Database was performed for patients ≤18 years of age in the United States. A total of 500 patients underwent m-MVR in 2009, 2012, 2016, and 2019. Patients with single ventricle physiology were excluded (n  =  13). These patients were categorized into three groups according to age: neonates (<1 month, n  =  20), infants (1-12 months, n  =  76 patients), and children (1-18 years, n  =  404). Outcomes were compared between the three groups. Results: The proportion of m-MVR involving children undergoing MV procedures (repair and replacement) has increased from 17.3% in 2009 to 30.8% in 2019 (Ptrend < .01). History of cardiac surgery was present in 256 patients (51.2%). Concomitant procedures were performed in 119 patients (23.8%). Intra- or postoperative extracorporeal membrane oxygenation was required in 19 patients (3.8%). The overall in-hospital mortality was 4.8% and was significantly higher in neonates and infants compared with older children (10% vs 11.8% vs 3.2%, P = .003). The length of hospital stay was longer in the neonatal group (median, 57 days, interquartile range, [24.8-90] vs 29.5 days [15.5-61] vs 10 days [7-18], P < .01). Nonhome discharges were more common in neonates and infants (40% vs 36.8% vs 13.1%, P < .01). Conclusion: Mechanical mitral valve replacement is increasingly performed over time with acceptable in-hospital morbidity and mortality, especially in older children and adolescents. Neonates and infants are associated with worse hospital survival, prolonged hospitalization, and significant rates of nonhome discharges.

Short-Term Mortality Among Pediatric Patients With Heart Diseases Undergoing Veno-Arterial Extracorporeal Membrane Oxygenation: A Systematic Review and Meta-Analysis

BACKGROUND

Veno-arterial extracorporeal membrane oxygenation serves as a crucial mechanical circulatory support for pediatric patients with severe heart diseases, but the mortality rate remains high. The objective of this study was to assess the short-term mortality in these patients.

METHODS AND RESULTS

We systematically searched PubMed, Embase, and Cochrane Library for observational studies that evaluated the short-term mortality of pediatric patients undergoing veno-arterial extracorporeal membrane oxygenation. To estimate short-term mortality, we used random-effects meta-analysis. Furthermore, we conducted meta-regression and binomial regression analyses to investigate the risk factors associated with the outcome of interest. We systematically reviewed 28 eligible references encompassing a total of 1736 patients. The pooled analysis demonstrated a short-term mortality (defined as in-hospital or 30-day mortality) of 45.6% (95% CI, 38.7%-52.4%). We found a significant difference (P<0.001) in mortality rates between acute fulminant myocarditis and congenital heart disease, with acute fulminant myocarditis exhibiting a lower mortality rate. Our findings revealed a negative correlation between older age and weight and short-term mortality in patients undergoing veno-arterial extracorporeal membrane oxygenation. Male sex, bleeding, renal damage, and central cannulation were associated with an increased risk of short-term mortality.

CONCLUSIONS

The short-term mortality among pediatric patients undergoing veno-arterial extracorporeal membrane oxygenation for severe heart diseases was 45.6%. Patients with acute fulminant myocarditis exhibited more favorable survival rates compared with those with congenital heart disease. Several risk factors, including male sex, bleeding, renal damage, and central cannulation contributed to an increased risk of short-term mortality. Conversely, older age and greater weight appeared to be protective factors.

Extracorporeal membrane oxygenation in paediatric cardiac surgery: 5-year single centre experience

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) has become an integral part of paediatric cardiac surgery. We report the experience of a well-established ECMO service over 5 years.

METHODS

This retrospective study analysed all paediatric patients who required ECMO support following cardiac surgery from April 2015 to March 2020. Inclusion criteria were age less than 18 years and post-operative ECMO support. Patients were analysed dividing into groups according to the urgency for ECMO support (extracorporeal cardiopulmonary resuscitation (ECPR) and cardiac ECMO) and according to age (neonatal and paediatric ECMO groups). They were followed for 30-day, 6-month mortality, long-term survival, postoperative morbidity and the need for reintervention.

RESULTS

Forty-six patients were included who had a total of venoarterial (VA) 8 ECMO runs. The 5-year incidence of the need for VA ECMO after cardiac surgery was 3.3% (48 of the overall 1441 cases recorded). The median follow-up period was 3.5 (interquartile ranges, 0.8-4.7) years. Thirty-day, 6-month and follow-up survival rate was 85%, 65% and 52% respectively. At the 6-month follow-up, the ECPR group showed a trend towards worse survival compared with the cardiac ECMO group (47% vs. 55%) but with no statistical significance (p = 0.35). Furthermore, the survival rates between paediatric (60%) and neonatal (46%) ECMO groups were similar, with no statistical significance (p = 0.45). The rate of acute neurological events was 27% (13/48).

CONCLUSION

ECPR and neonatal ECMO groups had higher mortality. VA ECMO 30-day and 6-month survival rates were 85% and 65% respectively. Major neurological injury resulting in ECMO termination occurred in 3 patients. Accumulated experiences and protocols in ECMO management can improve mortality and morbidity.

Risk Factors and Outcomes of Children with Congenital Heart Disease on Extracorporeal Membrane Oxygenation-A Ten-Year Single-Center Report

For children born with congenital heart defects (CHDs), extracorporeal life support may be necessary. This retrospective single-center study aimed to investigate the outcomes of children with CHDs on extracorporeal membrane oxygenation (ECMO), focusing on various risk factors. Among the 88 patients, 36 (41%) had a single-ventricle heart defect, while 52 (59%) had a biventricular defect. In total, 25 (28%) survived, with 7 (8%) in the first group and 18 (20%) in the latter. A p-value of 0.19 indicated no significant difference in survival rates. Children with biventricular hearts had shorter ECMO durations but longer stays in the intensive care unit. The overall rate of complications on ECMO was higher in children with a single ventricle (odds ratio [OR] 1.57, 95% confidence interval [CI] 0.67-3.7); bleeding was the most common complication in both groups. The occurrence of a second ECMO run was more frequent in patients with a single ventricle (22% vs. 9.6%). ECMO can be effective for children with congenital heart defects, including single-ventricle patients. Bleeding remains a serious complication associated with worse outcomes. Patients requiring a second ECMO run within 30 days have lower survival rates.

Outcomes of Extracorporeal Membrane Oxygenation in Patients After Repair of Congenital Heart Defects

Extracorporeal membrane oxygenation (ECMO) is widely used after congenital heart surgery. The purpose of this study is to analyze the factors influencing mortality and morbidity in patients who require ECMO support after congenital cardiac surgery. All 109 patients (5.8% of total cases) who underwent ECMO support after congenital heart surgery between January 2014 and 2021 were included in this single-center study. The mean age was 10.13 ± 20.55 months, and the mean weight was 6.41 ± 6.79 kg. 87 (79.8%) of the patients were under 1 year of age. A total of 54 patients (49.5%) were weaned successfully from ECMO support, and 27 of them (24.8%) were discharged. The childhood age group had the best outcomes. Seventy-seven percent of the children were weaned successfully, and 50% were discharged. 69 patients (63.3%) had biventricular physiology; weaning and survival outcomes were better than single ventricle patients (P-value 0.002 and < 0.001, respectively). Low cardiac output (n = 49; 44.9%) as an ECMO indication had better outcomes than extracorporeal cardiopulmonary resuscitation (n = 31; 28.4%) (P = 0.05). Most of the patients had ≥ 4 Modified Aristotle Comprehensive Complexity (MACC) levels, and higher MACC levels were associated with a higher mortality rate. The most common procedure was the Norwood operation (16.5%), with the worst outcome (5.5% survival). Bleeding and renal complications were the most common complications affecting outcomes. Results were more satisfactory in patients with biventricular repair, childhood, and lower MACC levels. Early initiation of ECMO in borderline patients without experiencing cardiac arrest or multiorgan failure may improve outcomes.

Bridging with Veno-Arterial Extracorporeal Membrane Oxygenation in Children: A 10-Year Single-Center Experience

Veno-arterial extracorporeal membrane oxygenation (V-A ECMO) is frequently used in children with and without congenital heart disease (CHD). This study, of a single-center and retrospective design, evaluated the use and timing of V-A ECMO in a pediatric cohort who underwent V-A ECMO implantation between January 2009 and December 2019. The patients were divided into a pre-/non-surgical group and a post-surgical group. Among the investigated variables were age, gender, weight, duration of ECMO, ECMO indication, and ventricular physiology, with only the latter being statistically relevant between the two groups. A total of 111 children (58 male/53 female), with a median age of 87 days (IQR: 7–623) were supported using V-A ECMO. The pre-/non-surgical group consisted of 59 patients and the post-surgical group of 52 patients. Survival at discharge was 49% for the pre-/non-surgical group and 21% for the surgical group (p = 0.04). Single-ventricle physiology was significant for a worse outcome (p = 0.0193). Heart anatomy still has the biggest role in the outcomes of children on ECMO. Nevertheless, children with CHD can be successfully bridged with ECMO to cardiac operation.

A narrative review of modern approach and outcomes evaluation in congenital heart defects

OBJECTIVE

The purpose of this review is to highlight critical advances and innovative approaches to the most challenging clinical situations in congenital heart surgery, to establish a new perspective from which to evaluate current clinical practice patterns and contemporary United States program ranking systems.

BACKGROUND

The past decades have witnessed substantial advances in the treatment of congenital heart defects. New strategies are deeply rooted in calculated risk-taking innovations. Pioneer surgeons developed, improved and refined critical operative skills and techniques to optimize cardiovascular physiology, decrease operative mortality and improve clinical outcomes.

METHODS

Unfortunately, in the modern surgical era, supportive environments to allow surgeons to make similar gains and innovative contributions remain scarce. In the current practice, overall procedure volume is prioritized to safeguard quality metrics, including hospital survival and length of stay, surgical complications, and neurocognitive outcomes. As a result, exceptional surgical results have become translated and defined by public ranking systems such as the US News and World Report Best Children's Hospital National Ranking (USNWR) and the Congenital Heart Surgery Database of the Society for Thoracic Surgeons (CHSD-STS), primary based upon early post-operative mortality. This reality places surgeons in a vulnerable position where pressure to achieve a high clinical ranking contrasts with a surgeon definition of "acceptable" surgical risk. Currently, the most frequently used risk stratification tools do not factor in important differences in strategies, such as staged palliation versus complete repair, or bi-ventricular versus uni-ventricular physiology. This favors hospitals pursuing multistage surgical approaches, even if the result is worse long-term morbidity, mortality and increased resource utilization. This economy of ranking-based decision-making causes surgeons either avoid operating altogether or accept less advantageous multi-staged treatment strategies for patients with elevated expected mortality. Such an environment also might present much farther-reaching negative impacts on the growth and development of junior surgeons and trainees, as well as on the pursuit of new surgical innovations to aid future generations of patients.

CONCLUSIONS

Risk aversive surgical behavior is creating an environment not favorable for the children born with truly complex congenital heart defects.

KEYWORDS

Biventricular conversion; congenital heart surgery; multidisciplinary approach; risk-stratification; surgical outcomes.