The Children's National Hospital Outcomes Registry: a plea for a benchmarking tool that provides longitudinal outcomes for patients and families.

Surgical advancements in paediatric cardiovascular surgery have led to improved survival rates for those patients with the most complex CHDs leading to greater numbers of patients who are living well into adulthood. Despite this new era of long-term survival, our current reporting systems continue to focus largely on using short-term postoperative outcomes as the criteria to both rate and rank hospitals. Using such limited criteria to rate and rank hospitals may mislead the intended audiences: patients and families. The goal of this article is to describe the creation of a local benchmarking report which aims to retrospectively review long-term outcomes from our single centre. This report is updated annually and published on our cardiac surgery webpage in an effort to be as transparent as possible for our patient and family communities.

Multiple Pediatric Extracorporeal Membrane Oxygenation Runs and Futility. What Are the Limits?

Despite high mortality rates, pediatric extracorporeal membrane oxygenation (ECMO) redeployments are frequently discussed in everyday clinical care. We aim to investigate predictors of mortality in those patients. Clinical data from a single pediatric center were retrospectively analyzed. Patients with multiple ECMO runs between 2010 and 2023 were included. A total of 70 (13%) patients required multiple ECMO runs. Of those, 56 (80%) died before discharge; late mortality was 89% at a median of 1.6 (1.0-3.9) years. A total of 47 (67%) patients had neurologic findings. Only one (1%) survivor had a normal neurodevelopmental follow-up. Duration of the first ECMO run (odds ratio [OR]: 2.63, 1.08-7.96), total duration on ECMO (OR: 4.72, 1.29-23.54), neurologic findings at any time (OR: 7.94, 1.46-43.24), need for renal replacement therapy (OR: 4.79, 1.06-25.58), and lactate values correlated with late mortality. All 19 (27%) patients with neurologic findings before the second run died. The frequency of multiple-run ECMOs increased within the study period. Outcomes in pediatric patients with multiple ECMO runs are disheartening. Given all patients in our cohort with neurological findings before the second ECMO run died, neurological findings should be taken into consideration when determining the utility of further ECMO support.

--Connecting Transcriptomics with Computational Modeling to Reveal Developmental Adaptations in Pediatric Human Atrial Tissue.

Nearly 1% of babies are born with congenital heart disease (CHD) - many of whom will require heart surgery within the first few years of life. A detailed understanding of cardiac maturation can help to expand our knowledge on cardiac diseases that develop during gestation, identify age-appropriate drug therapies, and inform clinical care decisions related to surgical repair and postoperative management. Yet, to date, our knowledge of the temporal changes that cardiomyocytes undergo during postnatal development is limited. In this study, we collected right atrial tissue samples from pediatric patients (n=117) undergoing heart surgery. Patients were stratified into five age groups. We measured age-dependent adaptations in cardiac gene expression, and used computational modeling to simulate action potential and calcium transients. Enrichment of differentially expressed genes (DEGs) revealed age-dependent changes in several key biological processes (e.g., cell cycle, structural organization), cardiac ion channels, and calcium handling genes. Gene-associated changes in ionic currents exhibited age-dependent trends, with changes in calcium handling (INCX) and repolarization (IK1) most strongly associated with an age-dependent decrease in the action potential plateau potential and increase in triangulation, respectively. We observed a shift in repolarization reserve, with lower IKr expression in younger patients, a finding potentially tied to an increased amplitude of IKs that could be triggered by elevated sympathetic activation in pediatric patients. Collectively, this study provides valuable insights into age-dependent changes in human cardiac gene expression and electrophysiology, shedding light on molecular mechanisms underlying cardiac maturation and function throughout development.

Left Atrioventricular Valve Regurgitation After Atrioventricular Septal Defect Repair.

BACKGROUND: Whether patients with moderate left atrioventricular valve regurgitation (LAVVR) after surgical repair of complete atrioventricular septal defect (CAVSD) should be observed or undergo reoperation remains unclear. METHODS: Moderate LAVVR was diagnosed in 87 of 220 patients who underwent CAVSD repair: 47 during the initial hospital stay and 40 after a median of 7 months (interquartile range, 2-18 months) after the initial operation. RESULTS: Of these 87 patients who had moderate LAVVR, 15 died, for an overall mortality of 17%. The regurgitation became severe in 39 patients (45%) within a median of 2 months (interquartile range, 1-7 months) leading to 33 reoperations and 10 deaths. In 23 of 87 patients (26%), regurgitation remained at a moderate level over a median follow-up period of 8 months (interquartile range, 1-48 months). In 25 of 87 patients (29%), the regurgitation decreased to mild after a median of 9 months (interquartile range, 5-19 months). The only independent risk factor for increased severity of regurgitation and reoperation was the echocardiographic appearance of the jet centered around the cleft rather than central at the time of diagnosis of moderate regurgitation (odds ratio, 3.5; 95% CI, 1.5-9.0; P = .007). CONCLUSIONS: Moderate LAVVR after CAVSD repair is often linked to death and reoperation, but regurgitation remains stable in one-quarter of patients and improves in one-third. The deterioration usually occurs within the first year after surgery. The initial observation of patients with residual or new moderate regurgitation for up to 1 year or until further deterioration seems reasonable, as long as the regurgitation is centrally located.

The Use of the CardioCel 3D 60° Patch for Aortic Arch Reconstruction in Infancy-A Word of Caution.

BACKGROUND: There are limited data on outcomes after implantation of the CardioCel 3D 60° patch in great vessel repair. After anecdotally witnessing an increase in negative outcomes, we reviewed our experience using this patch in our neonate and infant patients undergoing aortic arch repair. METHODS: Aortic arch repair with implantation of the CardioCel 3D 60° patch was performed in 24 patients between July 2018 and July 2021. Dominant cardiac morphologies were hypoplastic left heart syndrome (66%), atrioventricular canal defects (13%), and other (21%). Median age at implantation was 44 days (interquartile range [IQR], 6-112 days). Recurrent obstruction was defined as the need for reoperation or catheter intervention or recurrent peak pressure gradient of descending aorta ≥25 mm Hg on echocardiography. RESULTS: Five deaths occurred after a median of 217 days (IQR, 69-239 days). Twelve patients (50%) had recurrent obstruction. Three patients (13%) required redo aortic arch operation after a median of 148 days (IQR, 128-193 day), with extensive fibrous coating of the patch interior causing obstruction. Eleven patients (46%) required at least 1 balloon angioplasty on their aorta after a median of 102 days (IQR, 83-130 days) after repair, and 3 needed >1 catheter intervention. The estimated probability of having recurrent obstruction was 85% at 6 months and 71% at the 1-year follow (P = .06). CONCLUSIONS: Recurrent aortic obstruction occurred in half of our patients shortly after repair. The use of the CardioCel 3D 60° patch for aortic arch reconstruction in neonates and infants should be reevaluated.

Excellent Survival With a Focus on Pulmonary Artery Reinterventions After the Arterial Switch Operation.

Background: We sought to evaluate the outcomes in patients who underwent the arterial switch operation (ASO) over a 20-year period at a single institution. Methods: The current study is a retrospective review of 180 consecutive patients who underwent the ASO for biventricular surgical correction of dextro-transposition of the great arteries (d-TGA) between 2002 and 2022. Results: Among 180 patients, 121 had TGA-intact ventricular septum, 47 had TGA-ventricular septal defect and 12 had Taussig-Bing Anomaly (TBA). The median follow-up time was 6.7 years (interquartile range: 3.9-8.7 years). There were five early (2.8%) and one late (0.6%) mortality. Survival was 96.6% at one year and beyond. Reoperations were performed in 31 patients (17%). Taussig Bing Anomaly was found to increase the risk of reoperation by 17 times (P < .0001). A total of 37 (21%) patients underwent 53 reinterventions (14 surgical procedures, 39 catheter interventions) specifically addressing pulmonary artery (PA) stenosis. Freedom from PA reintervention was 97%, 87%, 70%, and 55% at 1, 5, 10, and 15 years, respectively. By bivariable analysis, TBA (P = .003, odds ratio [OR]: 6.4, 95% confidence interval [CI]: 1.9-21.7), mild PA stenosis at discharge (P ≤ .001, OR: 6.1, 95% CI: 2.7-13.6), and moderate or severe PA stenosis at discharge (P ≤ .001, OR: 12.7, 95% CI: 5-32.2) were identified as predictors of reintervention on PA. In the last follow-up of 174 survivors, 24 patients (14%) had moderate or greater PA stenosis, two (1%) had moderate neoaortic valve regurgitation, and 168 were New York Heart Association status I. Conclusions: Our results demonstrated excellent survival and functional status following the ASO for d-TGA; however, patients remain subject to frequent reinterventions especially on the pulmonary arteries.

Survival benefits of the wait-and-grow approach in small babies (≤2000 g) requiring heart surgery.

Objective: The best approach to minimize the observed higher mortality of newborn infants with low birth weight who require congenital heart surgery is unclear. This retrospective study was designed to review outcomes of newborn infants weighing <2000 g who have undergone cardiovascular surgery to identify patient parameters and clinical strategies for care associated with higher survival. Methods: A retrospective chart review of 103 patients who underwent cardiovascular surgery from 2010 to 2021 who were identified as having low birth weight (≤2000 g). Patients who underwent only patent ductus arteriosus ligation or weighing >3500 g at surgery were excluded. Results: Median age was 24 days and weight at the time of surgery was 1920 g. Twenty-six (25%) operative mortalities were recorded. Median follow-up period was 2.7 years. The 1- and 3-year overall Kaplan-Meier survival estimate was 72.4% ± 4.5% and 69.1% ± 4.6%. The 1-year survival of patients who had a weight increase >300 g from birth to surgery was far superior to the survival of those who did not achieve such a weight gain (81.4% ± 5.6% vs 64.0% ± 6.7%; log-rank P = .04). By multivariable Cox-hazard regression analysis, the independent predictor of 1-year mortality was genetic syndrome (hazard ratio, 3.54; 95% CI, 1.67-7.82; P < .001), whereas following a strategy of increasing weight from birth to surgery resulted in lower mortality (hazard ratio, 0.49; 95% CI, 0.24-0.90; P = .02). Conclusions: A strategy of wait and grow for newborn infants with very low birth weight requiring heart surgery results in better survival than immediate surgery provided that the patient's condition allows for this waiting period.

Connecting Transcriptomics with Computational Modeling to Reveal Developmental Adaptations in the Human Pediatric Myocardium.

Background: Nearly 1% or 1.3 million babies are born with congenital heart disease (CHD) globally each year - many of whom will require palliative or corrective heart surgery within the first few years of life. A detailed understanding of cardiac maturation can help to expand our knowledge on cardiac diseases that develop during gestation, identify age-appropriate cardiovascular drug therapies, and inform clinical care decisions related to surgical repair, myocardial preservation, or postoperative management. Yet, to date, our knowledge of the temporal changes that cardiomyocytes undergo during postnatal development is largely limited to animal models. Methods: Right atrial tissue samples were collected from n=117 neonatal, infant, and pediatric patients undergoing correct surgery due to (acyanotic) CHD. Patients were stratified into five age groups: neonate (0-30 days), infant (31-364 days), toddler to preschool (1-5 years), school age (6-11 years), and adolescent to young adults (12-32 years). We measured age-dependent adaptations in cardiac gene expression, and used computational modeling to simulate action potential and calcium transients. Results: Enrichment of differentially expressed genes (DEG) was explored, revealing age-dependent changes in several key biological processes (cell cycle, cell division, mitosis), cardiac ion channels, and calcium handling genes. Gene-associated changes in ionic currents exhibited both linear trends and sudden shifts across developmental stages, with changes in calcium handling ( I NCX ) and repolarization ( I K1 ) most strongly associated with an age-dependent decrease in the action potential plateau potential and increase in triangulation, respectively. We also note a shift in repolarization reserve, with lower I Kr expression in younger patients, a finding likely tied to the increased amplitude of I Ks triggered by elevated sympathetic activation in pediatric patients. Conclusion: This study provides valuable insights into age-dependent changes in human cardiac gene expression and electrophysiology among patients with CHD, shedding light on molecular mechanisms underlying cardiac development and function across different developmental stages.

Alarming rate of liver cirrhosis after the small conduit extracardiac Fontan: A comparative analysis with the lateral tunnel.

BACKGROUND: The association between the prevalence of cirrhosis and the types of Fontan operations remains unclear. METHODS: We conducted a retrospective chart review of 332 patients who underwent the Fontan procedure at our institution. Four patients who underwent the atriopulmonary connection Fontan were excluded from the analysis. Patients who had intracardiac-extracardiac conduit (126) between 1989 and 2021 were pooled with those having extracardiac conduit (ECC) (134). The 260 patients who underwent the ECC and the 68 patients who had the lateral tunnel (LT) Fontan constitute the core of the study. RESULTS: Median age at the Fontan procedure was 23.7 months (interquartile range [IQR], 20.8-32.6) in the LT group, compared with 28.8 months (IQR, 24.6-39.5) in the ECC group (P < .01). The median follow-up was 14.8 years (IQR, 12.5-16.5) in the LT group and 7 years (IQR, 2.8-10.4) in the extracardiac conduit group. During the follow-up period, 3 patients (4.4%) with LT and 17 patients (6.5%) with ECC (11 patients with 16 mm or less conduit size) were diagnosed with cirrhosis. The prevalence of cirrhosis at 1, 5, 10, and 15 years was 0%, 0%, 0%, and 4.4% in the LT group, respectively, and 0%, 0.9%, 7.7%, and 29.8% in the ECC group (P < .01) Rates of mortality, Fontan revision, Fontan takedown, transplant, and complications were comparable between the 2 groups. CONCLUSIONS: The extracardiac conduit Fontan seems to be associated with faster development of cirrhosis.

Repair of the complete atrioventricular septal defect-impact of postoperative moderate or more regurgitation.

OBJECTIVES: To study the risk factors for mortality, moderate or more left atrioventricular valve regurgitation (LAVVR) and reoperation after the surgical repair of complete atrioventricular septal defect (cAVSD) in a single centre. METHODS: The current study is a retrospective review of patients who underwent surgical repair of cAVSD between 2000 and 2021. Patients with unbalanced ventricles not amenable to biventricular repair, double outlet right ventricle and malpositioned great arteries were excluded. The clinical predictors of outcome for end points were analysed with univariate and multivariable Cox regression analysis or Fine-Gray modelling for competing risks. Time-dependent end points were estimated using the Kaplan-Meier curve analysis and cumulative incidence curves. RESULTS: The median follow-up time was 2.3 years. Among 220 consecutive patients were 10 (4.6%) operative and 21 late mortalities (9.6%). A total of 26 patients were identified to have immediate postoperative moderate or more regurgitation and 10 of them ultimately died. By multivariable analysis prematurity and having more than moderate regurgitation immediately after the operation were identified as predictors of overall mortality (P = 0.003, P = 0.012). Five- and ten-year survival rates were lower for patients with immediate postoperative moderate or more LAVVR {51.9% [confidence interval (CI): 27.5-71.7%]} when compared to patients without moderate or more regurgitation [93.2% (CI: 87.1-96.4%) and 91.3% (CI: 83.6-95.5%)]. CONCLUSIONS: The patients who undergo cAVSD repair remain subjected to a heavy burden of disease related to postoperative residual LAVVR. Immediate postoperative moderate or more LAVVR contributes significantly to overall mortality. Whether a second run of bypass can decrease this observed mortality should be investigated.

Prevalence and clinical implications of heightened plastic chemical exposure in pediatric patients undergoing cardiopulmonary bypass.

BACKGROUND: Phthalate chemicals are used to manufacture plastic medical products, including many components of cardiopulmonary bypass (CPB) circuits. We aimed to quantify iatrogenic phthalate exposure in pediatric patients undergoing cardiac surgery and examine the link between phthalate exposure and postoperative outcomes. STUDY DESIGN AND METHODS: The study included pediatric patients undergoing (n=122) unique cardiac surgeries at Children's National Hospital. For each patient, a single plasma sample was collected preoperatively and two additional samples were collected postoperatively upon return from the operating room and the morning after surgery. Concentrations of di(2-ethylhexyl) phthalate (DEHP) and its metabolites were quantified using ultra high-pressure liquid chromatography coupled to mass spectrometry. RESULTS: Patients were subdivided into three groups, according to surgical procedure: (1) cardiac surgery not requiring CPB support, (2) cardiac surgery requiring CPB with a crystalloid prime, and (3) cardiac surgery requiring CPB with red blood cells (RBCs) to prime the circuit. Phthalate metabolites were detected in all patients, and postoperative phthalate levels were highest in patients undergoing CPB with an RBC-based prime. Age-matched (<1 year) CPB patients with elevated phthalate exposure were more likely to experience postoperative complications. RBC washing was an effective strategy to reduce phthalate levels in CPB prime. DISCUSSION: Pediatric cardiac surgery patients are exposed to phthalate chemicals from plastic medical products, and the degree of exposure increases in the context of CPB with an RBC-based prime. Additional studies are warranted to measure the direct effect of phthalates on patient health outcomes and investigate mitigation strategies to reduce exposure.

Reconstruction of Fibrous Skeleton of the Heart for Double-Valve Replacement in A Pediatric Patient - Modified Commando Procedure.

The so-called Commando procedure, initially described by David and colleagues, consists in the reconstruction of the mitro-aortic fibrous lamina by a patch that enlarges both annuli. Its use has been described to upsize the aortic and mitral annulus for double valve replacement in adolescents. We describe a modified technique of this reconstruction of the fibrous skeleton of the heart, combined with Konno procedure to further enlarge the aortic annulus. In modified Commando procedure, following the reconstruction of aortomitral continuity with a bovine pericardium CardioCel patch (Admedus Regen Pty Ltd, Perth, WA, Australia), an aortic valved conduit that was made on the bench in order to have bottom skirt that enabled the suturing of the composite conduit far inside the left ventricle outflow tract. Coronary buttons were implanted at the supra-commissural level. The advantages of this modified Commando procedure are (1) the creation of a new aortic annulus when the integrity of this annulus has been compromised, (2) the upsizing of both annuli to any possible size of aortic and mitral prostheses, and (3) the relief of any residual left ventricular outflow tract obstruction.

Real-Time Detection of Circulating Thrombi in an Extracorporeal Circuit Using Doppler Ultrasound: In-Vitro Proof of Concept Study.

BACKGROUND: Thromboembolic stroke continues to be by far the most common severe adverse event in patients supported with mechanical circulatory assist devices. Feasibility of using Doppler ultrasound to detect circulating thrombi in an extracorporeal circuit was investigated. METHODS: A mock extracorporeal circulatory loop of uncoated cardiopulmonary bypass tubing and a roller pump was setup. A Doppler bubble counter was used to monitor the mean ultrasound backscatter signal (MUBS). The study involved two sets of experiments. In Scenario 1, the circuit was sequentially primed with human blood components, and the MUBS was measured. In Scenario 2, the circuit was primed with heparinized fresh porcine blood, and the MUBS was measured. Fresh blood clots (diameter <1,000 microns, 1,000-5,000 microns, >5,000 microns) were injected into the circuit followed by protamine administration. RESULTS: In Scenario 1 (n = 3), human platelets produced a baseline MUBS of 1.5 to 3.5 volts/s. Addition of packed human red blood cells increased the baseline backscatter to 17 to 21 volts/s. Addition of fresh frozen plasma did not change the baseline backscatter. In Scenario 2 (n = 5), the blood-primed circuit produced a steady baseline MUBS. Injection of the clots resulted in abrupt and transient increase (range: 3-30 volts/s) of the baseline MUBS. Protamine administration resulted in a sustained increase of MUBS followed by circuit thrombosis. CONCLUSIONS: Doppler ultrasound may be used for real-time detection of circulating solid microemboli in the extracorporeal circuit. This technology could potentially be used to design safety systems that can reduce the risk of thromboembolic stroke associated with mechanical circulatory support therapy.

Narrowing Down the Symptomatology of Isolated Vascular Rings in Children.

Vascular rings may cause respiratory or gastrointestinal symptoms due to compression of the trachea and/or esophagus. Advances in imaging have enabled early detection in asymptomatic patients posing new management dilemmas. Surgery is expected to relieve symptoms, although this has not been well studied. We sought to evaluate the presence and pattern of symptoms associated with vascular rings before surgical intervention and to detail symptom resolution after surgery. A 10-year retrospective review of patients diagnosed with an isolated vascular ring was performed between January 2010 and December 2019. 100 patients were identified; 35 double aortic arch (DAA) and 65 right aortic arch and left ligamentum arteriosum (RALL). 73 patients were symptomatic on presentation; 47 had respiratory, 5 had gastrointestinal, and 21 had both types of symptoms. Surgical repair was performed in 75 patients; 74 were symptomatic. Respiratory symptoms were more likely in patients with preoperative tracheal narrowing (p < 0.001). Moderate-severe respiratory symptoms led to surgery in RALL patients (OR 10.6, p = 0.0001). DAA patients were more likely to undergo surgery (p < 0.001) irrespective of symptom severity. At a median post-surgical follow-up of 4 months, there was a significant reduction in symptom burden (p < 0.001), except for asthma symptoms (p = 0.131). Symptom resolution was not dependent on the vascular ring anatomy (p = 0.331) or the age at operation (p = 0.158). Vascular rings are typically accompanied by respiratory symptoms and less commonly GI symptoms, both of which resolve in most patients after surgery. Those who present predominantly with asthma-like symptoms may not achieve resolution after surgery.

Perioperative Morbidity and Outcomes in Pediatric Patients Transitioned From Extracorporeal Membrane Oxygenation to Ventricular Assist Device Support: A Study of the Society of Thoracic Surgeons Congenital Heart Surgery Database.

As a bridge to transplant strategy, children transitioned from extracorporeal membrane oxygenation (ECMO) to ventricular assist device (VAD) have higher waitlist mortality compared with those who receive de novo VAD. However, the contribution of the immediate perioperative period and differences in the two groups are not well studied. We performed a nested case-control study between children receiving de novo VAD (group 1) and those transitioned from ECMO to VAD (group 2) between 2014 and 2019 using The Society of Thoracic Surgeons (STS) database. A total of 735 children underwent VAD placement with 498 in group 1 and 237 in group 2. Patients in group 2 were significantly younger, smaller, and significantly sicker, were twice as likely to transition to biventricular VAD and need unplanned reoperations. Overall mortality was 16% for group 1 and 34% for group 2 ( p < 0.01). Regression analysis showed that ECMO use (odds ratio [OR], 2.17 [1.3-3.4]), ventilator need (OR, 2.2 [1.3-3.9]), and cardiogenic shock (OR, 1.8 [1.2-2.8]) were all independent preoperative predictors of VAD mortality while dialysis need (OR, 25.5 [8.6-75.3]), stroke (OR, 6.2 [3.1-12.6]), and bleeding (OR, 1.9 [1.1-3.4]) were independent postoperative predictors of VAD mortality within 30 days (all p < 0.05). The study demonstrated significant baseline differences between the two cohorts, warranting avoidance of comparison. Early elective VAD placement in this cohort of patients should be sought to avoid interim ECMO and high post-VAD mortality.

Gaseous Nitric Oxide-Cangrelor Combination to Prevent Clots in Extracorporeal Life Support System.

INTRODUCTION: The objective of this study was to investigate the potential synergistic utility of a combination of gaseous nitric oxide (gNO)-intravenous Cangrelor as an effective pharmacological option for the prevention of thrombosis in an animal model of extracorporeal life support (ECLS) circuits. METHODS: 10 newborn lambs were placed on ECLS. 5 of them were administered a combination of gNO and intravenous Cangrelor. The remaining 5 were not administered any anticoagulant. The primary end point was duration of ECLS without clot formation. The secondary outcome measure was the absolute maximum transmembrane pressure gradient. RESULTS: The mean duration of ECLS were 168 min (standard deviation 224.98 min) in the control group and 402 min (standard deviation 287.5 min) in the experimental group (P = 0.17). The peak trans-oxygenator pressure difference was 43 mm Hg (standard deviation 23 mm Hg) in the control group and 62 mm Hg (standard deviation 71 mm Hg) in the experimental group(P = 0.64). Two animals in the experimental group were supported up to 12 h without clot formation. Clot formation in the experimental group occurred after placement of the cannulae but prior to initiation of ECLS flows after cannulation. CONCLUSIONS: A combination of gNO and Cangrelor is prevents clot formation in an experimental animal model when administered through a clean clot-free circuit. However, the combination s ineffective when there are pre-existing clots in the circuit. A bolus of anticoagulation prior to cannulation is needed prior to testing this combination in future studies with a larger sample size.