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.

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.

In vitro investigation of axial mechanical support devices implanted in the novel convergent cavopulmonary connection Fontan.

OBJECTIVES: The 2 opposing inflows and 2 outflows in a total cavopulmonary connection make mechanical circulatory support (MCS) extremely challenging. We have previously reported a novel convergent cavopulmonary connection (CCPC) Fontan design that improves baseline characteristics and provides a single inflow and outflow, thus simplifying MCS. This study aims to assess the feasibility of MCS of this novel configuration using axial flow pumps in an in vitro benchtop model. METHODS: Three-dimensional segmentations of 12 single-ventricle patients (body surface area 0.5-1.75 m2) were generated from cardiovascular magnetic resonance images. The CCPC models were designed by connecting the inferior vena cava and superior vena cava to a shared conduit ascending to the pulmonary arteries, optimized in silico. The 12 total cavopulmonary connection and their corresponding CCPC models underwent in vitro benchtop characterization. Two MCS devices were used, the Impella RP® and the PediPump. RESULTS: MCS successfully and symmetrically reduced the pressure in both vena cavae by >20 mmHg. The devices improved the hepatic flow distribution balance of all CCPC models (Impella RP®P = 0.045, PediPump P = 0.055). CONCLUSIONS: The CCPC Fontan design provides a feasible MCS solution for a failing Fontan by balancing hepatic flow distribution and symmetrically decompressing the central venous pressure. Cardiac index may also improve with MCS. Additional studies are needed to evaluate this concept for managing Fontan failure.

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.

Clinical Profile and Outcomes of Rheumatic Heart Disease Patients Undergoing Surgical Valve Procedures in Uganda.

Background: Chronic valvular heart disease is a well-known, long-term complication of acute rheumatic fever (ARF), which remains a major public health problem in low- and middle-income countries. Access to surgical management remains limited. Outcomes of the minority proportion of patients that access surgery have not been described in Uganda. Objectives: To describe the volume and type of rheumatic heart disease (RHD) valvular interventions and the outcomes of operated patients in the Uganda RHD registry. Methods: We performed a retrospective cohort study of all valve surgery procedures identified in the Uganda RHD registry through December 2021. Results: Three hundred and sixty-seven surgical procedures were performed among 359 patients. More than half were among young (55.9% were ≤20 years of age), female (59.9%) patients. All patients were censored at 15 years. The median (IQR) follow up period was 43 (22,79) months. Nearly half of surgeries (46.9%) included interventions on multiple valves, and most valvular operations were replacements with mechanical prostheses (96.6%). Over 70% of the procedures were sponsored by charity organizations. The overall mortality of patients who underwent surgery was 13% (47/359), with over half of the mortalities occurring within the first year following surgery (27/47; 57.4%). Fifteen-year survival or freedom from re-operation was not significantly different between those receiving valve replacements and those receiving valve repair (log-rank p = 0.76). Conclusions: There has been increasing access to valve surgery among Ugandan patients with RHD. Post-operative survival is similar to regionally reported rates. The growing cohort of patients living with prosthetic valves necessitates national expansion and decentralization of post-operative care services. Major reliance on charity funding of surgery is unsustainable, thus calling for locally generated and controlled support mechanisms such as a national health insurance scheme. The central illustration (Figure 1) provides a summary of our findings and recommendations.

Cardiac surgical outcomes of patients with heterotaxy syndrome.

Objectives: The study objectives were to analyze the outcomes of pediatric patients with heterotaxy syndrome undergoing cardiovascular surgery and to determine the predictors of mortality. Methods: A retrospective analysis of 82 patients diagnosed with heterotaxy syndrome who underwent cardiovascular surgery between January 2008 and December 2017 was performed. Univariate and multivariable Cox regression analyses to determine risk factors for mortality and Kaplan-Meier analysis for survival were performed. Results: Patient mortality in the cohort was 34% (28/82), including 36% (20/55) for single ventricle palliation and 30% (8/27) for biventricular repair. At 5 years, the probability of survival did not differ between the groups by log-rank testing (P = .829). Multivariable analysis found extracorporeal membrane oxygenation support (hazard ratio, 10.4; 95% confidence interval, 4.3-25.4; P < .001), total anomalous pulmonary venous return (hazard ratio, 4.3; 95% confidence interval, 1.7-10.8; P = .002), and birth weight 2.5 kg or less (hazard ratio, 2.4; 95% confidence interval, 1.0-5.4; P = .041) to be independent risk factors for mortality in all-comers. Pulmonary vein stenosis was a univariate predictor of mortality among all patients with heterotaxy (hazard ratio, 3.0; 95% confidence interval, 1.4-6.4; P = .005) and in the subgroup of patients with single ventricles (hazard ratio, 4.0; 95% confidence interval, 1.7-9.7; P = .002). Overall survival was 66% (54/82) at a median follow-up time of 2.2 years (0.4-4.1) from the initial surgery. Conclusions: Outcomes of children with heterotaxy syndrome, irrespective of the operative pathway, remain suboptimal in the current era. Risk factors for mortality in this population include birth weight 2.5 kg or less, extracorporeal membrane oxygenation, pulmonary vein stenosis, and total anomalous pulmonary venous return, which may help to further optimize surgical decision making. Multiorgan system involvment is frequently encountered in these patients.

Fate of aortic regurgitation after isolated repair of ventricular septal defect with concomitant aortic regurgitation in children.

Objectives: The aim of the study was to evaluate the course of aortic valve regurgitation in patients with preoperative aortic valve regurgitation and ventricular septal defect who underwent repair of the ventricular septal defect without aortic valve repair. Methods: A total of 37 consecutive patients with a ventricular septal defect and aortic regurgitation who underwent surgery between April 2007 and March 2016 were included in the study. Demographic, echocardiographic, operative, and clinical data were reviewed. Early and late mortality and morbidity were analyzed. Aortic regurgitation grade, left ventricular function, and dimensions were compared between the preoperative transesophageal echocardiography and postoperative transthoracic echocardiogram at last follow-up. Multivariate logistic regression analysis was performed to determine factors associated with improvement of aortic valve function. Results: There was no early or late mortality. No reoperations or reinterventions were required. A total of 17 patients had mild or greater aortic regurgitation preoperatively. Only 5 patients had mild or greater aortic regurgitation at follow-up of 4.3 years (0.5-10.1). Twenty-eight (76%) of the 37 patients showed an improvement in their aortic regurgitation grade. Left ventricular end-systolic and end-diastolic diameter z-scores were significantly lower at follow-up (P = .007 and P = .001, respectively). Multivariable logistic regression identified low preoperative left ventricular ejection fraction as the only predictor of nonimprovement of aortic regurgitation (95% confidence interval, 0.732-0.999, P = .002). Conclusions: Repair of a ventricular septal defect with accompanying aortic regurgitation can be performed with excellent results without surgical intervention on the aortic valve. Accompanying aortic regurgitation, especially trivial to mild, at the time of ventricular septal defect repair improves in the majority of cases. Low preoperative left ventricular ejection fraction is predictive of nonimprovement of aortic regurgitation grade.

Influence of Body Mass Index in Donor-Recipient Size Mismatch in Pediatric Heart Transplantation.

BACKGROUND: Body weight is the traditional metric for matching donor and recipient size for pediatric heart transplantation (pHT). We hypothesized that mismatch in body mass index (BMI) or body surface area (BSA) rather than weight is better associated with outcomes of transplantation and therefore should be used for donor-recipient size matching. METHODS: Analysis of the United Network for Organ Sharing database limited to pHT recipients was performed. Donor and recipient mismatch groups were created for weight, BMI, and BSA ratios. Differences in recipient characteristics between each cohort and the impact of mismatch on outcomes were statistically analyzed. RESULTS: A total of 4,465 patients were included in the analysis of which 43% had congenital heart disease (CHD). There were significant differences in patient characteristics by matching, independent of the matching parameter. Multivariable regression analysis showed that a low donor-recipient BMI ratio (compared to normal) (CHD OR 1.70; non-CHD 2.78) was a predictor of one-year mortality (all P < .001) in both CHD and non-CHD cohorts. Low BMI ratio was also associated with worse long-term survival in non-CHD groups, but not in the CHD cohort. Weight and BSA ratio did not predict one year or long-term survival. CONCLUSION: The use of low BMI donors compared to recipient may predict poor early and long-term survival and therefore should be avoided in pHT. The use of BMI matching may improve donor-recipient matching in pHT.

Systematic Review of Slide Tracheoplasty Outcomes.

OBJECTIVE: To identify factors predicting success in slide tracheoplasty surgery at a regional children's hospital and compare with available published literature. MEASURES: Retrospective chart review comparing demographics (age, weight) and clinical (operative and hospital course, need for additional airway intervention) factors experienced with slide tracheoplasty. Findings were compared with a systematic review of published literature. RESULTS: Of the 16 tracheal stenosis patients in our cohort, 13 (81.3%) presented with an additional congenital or cardiovascular anomaly. When adjusted for cardiovascular anomalies, congenital tracheal stenosis patients had a mean age of 5.2 months (range 6 days-17 months), mean weight of 5.04 kg, and average ICU and hospital length of stay of 31.5 and 36.0 days, respectively. Tracheostomy was required for 4 patients and no early deaths were recorded. Of the 391 children in the grouped cohort, mean age and weight was older at 7.67 months and larger at 5.70 kg. Length of stay in both ICU and overall hospital course was 31.6 and 43.5 days, respectively. Mortality etiology for 44 patients was reported: 17 (38.6%) cardiac-related and 28 (63.6%) late mortalities. Our overall calculated mortality risk of 1.26 (P < .05) was lower than reported ratios of 2.0+. CONCLUSION: Despite the numerous institutional studies involving tracheal stenosis, mortality and surgical challenges remain high. Future studies with the inclusion of specific perioperative data can prove to further evaluate correlations between presentation characteristics and mortality.

Effect of preoperative extracorporeal membrane oxygenation therapy on postventricular assist device outcomes: an analysis of the STS Pedimacs database.

OBJECTIVES: Extracorporeal membrane oxygenation (ECMO) support prior to ventricular assist device (VAD) therapy is frequently used for stabilizing INTERMACS 1 and 2 paediatric patients. Data regarding outcomes with this strategy is limited. METHODS: Patient characteristics and outcomes post-VAD therapy with and without preop ECMO support were compared. Survival and risk factor analysis was performed for all patients and INTERMACS profile 1 subgroup. RESULTS: Of 541 INTERMACS 1 and 2 patients enrolled in Paediatric Interagency Registry for Mechanical Circulatory Support registry, 391 received primary VAD implantation and ECMO prior to VAD therapy was utilized in 150 patients. Younger age (P < 0.0001) and shock (P < 0.0001) were more common in group 2, with lower survival at 1, 6 and 12 months compared to group 1 (P < 0.0001). Freedom from infection (P = 0.03) was higher in group 1. Freedom from stroke (P = 0.7) was similar. Paracorporeal continuous flow devices led to poor survival in both groups 1 and 2 (P = 0.4). Implantable continuous flow (P < 0.0001) and paracorporeal pulsatile devices (P = 0.007) had better survival in primary VAD group. INTERMACS profile 1, lower weight, hepatic dysfunction, renal failure, paracorporeal continuous and percutaneous devices were associated with higher mortality. Preop ECMO therapy was not associated with higher mortality (P = 0.12). Survival of INTERMACS profile 1 patient was similar at 1, 6 and 12 months in both groups (P = 0.1). CONCLUSIONS: INTERMACS profile 1, lower weight, hepatic dysfunction, renal failure and use of paracorporeal continuous flow or percutaneous assist devices are associated with a higher postoperative mortality. Preop ECMO therapy however is not independently associated with higher postop mortality.

Cerebral Sinus Venous Thrombosis in Infants after Surgery for Congenital Heart Disease.

OBJECTIVE: To determine the prevalence of and risk factors for cerebral sinus venous thrombosis (CSVT) in neonates undergoing congenital heart disease (CHD) repair. STUDY DESIGN: Neonates who had CHD repair with cardiopulmonary bypass and postoperative brain magnetic resonance imaging (MRI) between 2013 and 2019 at a single tertiary care center were identified from institutional databases. Demographic, clinical, and surgical data were abstracted from these databases and from the medical record; 278 neonates with CHD had cardiopulmonary bypass, 184 of whom had a postoperative brain MRI. RESULTS: Eight patients (4.3%) had a CSVT. Transposition of the great arteries with an intact ventricular septum (P < .01) and interrupted aortic arch (P = .02) were associated with an increased risk for CSVT. Other risk factors for CSVT included cross-clamp time (98 [IQR, 77.5-120] minutes vs 67 [IQR, 44-102] minutes; P = .03), units of platelets (3.63 [IQR, 3-4] vs 2.17 [IQR, 1-4]; P < .01) and packed red blood cells (0.81 [IQR, 0.25-1] vs 1.21 [IQR, 1-1]; P = .03) transfused intraoperatively, and time between surgery and MRI (10 [IQR, 7-12.5] days vs 20 [IQR, 12-35] days; P < .01). Five patients (62.5%) were treated with anticoagulation. All patients had complete or partial resolution of their CSVT, regardless of treatment. CONCLUSIONS: Brain MRI after cardiopulmonary bypass in neonates revealed a low prevalence of CSVT (4.3%). Further studies are needed to establish best practices for surveillance, prevention, and treatment of CSVT in this population.

Compression Device-Assisted Extracorporeal Cardiopulmonary Resuscitation Cannulation in Pediatric Patients-A Simulation Study.

Background: Surgical neck cannulation for pediatric extracorporeal cardiopulmonary resuscitation (ECPR) requires multiple interruptions of manual chest compressions to facilitate the procedure. Effective uninterrupted CPR is essential to prevent neurological injury. We hypothesized that an automated chest compression device can be used to provide effective and uninterrupted chest compressions during pediatric neck ECPR cannulation. The feasibility of surgically cannulating the right carotid artery and right internal jugular vein in an infant during ongoing automated chest compressions was tested in a simulation study. Methods: A working prototype of a pediatric chest compression device was designed to provide automated chest compressions on an infant CPR manikin at the rate of 120 compressions/minute. A feedback device attached to the manikin was used to monitor the effectiveness of CPR. A synthetic artery, vein along with carotid sheath and skin was utilized to simulate surgical neck exploration. ECPR simulation was conducted using the compression device to provide chest compressions. Results: Four ECPR simulations were conducted during which vessel sparing (n = 2) and non-vessel sparing (n = 2) cannulation of the right internal carotid artery and right internal jugular vein were performed during ongoing mechanical chest compressions. All four cannulations were successfully performed without the need to interrupt chest compressions. Conclusions: In a simulated environment, pediatric ECPR neck cannulation with uninterrupted chest compressions may be accomplished using an automated chest compression device. The strategy of compression device-assisted ECPR cannulation requires further study and could potentially reduce the neurological complications of ECPR.

Mechanical support of pulmonary blood flow as a strategy to support the Norwood circulation-lumped parameter model study.

OBJECTIVES: We hypothesize that mechanical assistance of the pulmonary blood flow in a Norwood circulation can increase systemic blood flow and oxygen delivery. The aim of the study was to compare haemodynamics of an unassisted Norwood Blalock-Taussig shunt circulation with a mechanically assisted pulmonary flow-based Norwood circulation, using a lumped parameter computational model. METHODS: A neonatal circulatory lumped parameter model was developed to simulate a Norwood circulation with a 3.5-mm Blalock-Taussig shunt in a 3.5-kg neonate. A roller pump circulatory assist device with an inflow bladder was incorporated into the Norwood circulation to mechanically support the pulmonary circulation. Computer simulations were used to compare the haemodynamics of the assisted and unassisted circulations. Assisted and unassisted models with normal (56%) and reduced ejection fraction (30%) were compared. RESULTS: Compared to the unassisted Norwood circulation, the systemic flow in the assisted Norwood increased by 25% (ejection fraction = 56%) and 41% (ejection fraction = 30%). The central venous pressure decreased by up to 3 mmHg (both ejection fraction = 56% and ejection fraction = 30%) at a maximum pulmonary assist flow of 800 ml/min. Initiation of assisted pulmonary flow increased the arterial oxygen saturation by up to 15% and mixed venous saturation by up to 20%. CONCLUSIONS: This study demonstrates that an assisted pulmonary flow-based Norwood circulation has higher systemic flow and oxygen delivery compared to a standard Norwood Blalock-Taussig shunt circulation.

Association Between Exogenous Nitric Oxide Given During Cardiopulmonary Bypass and the Incidence of Postoperative Kidney Injury in Children.

OBJECTIVE: To compare the incidence and severity of acute kidney injury (AKI) after cardiac surgery with cardiopulmonary bypass and the administration of exogenous nitric oxide in children. DESIGN: A retrospective cohort study. SETTING: A single institution, university hospital. PARTICIPANTS: All children younger than 18 years of age who underwent surgery with cardiopulmonary bypass. INTERVENTIONS: Medical records of all eligible patients between January 4, 2017, and June 28, 2019, were reviewed. Patients were divided into two groups based on whether they received exogenous nitric oxide. MEASUREMENTS AND MAIN RESULTS: The primary endpoint was a change in serum creatinine level, defined as the difference between the preoperative creatinine and peak postoperative creatinine. The secondary endpoint was the incidence and severity of postoperative AKI. A difference-in-difference method using fixed-effect multiple linear regression was carried out to compare the difference in maximum serum creatinine changes between the control and intervention groups. Five hundred ninety-one patients were included in the analysis: 298 (50.5%) in the control group and 293 (49.5%) in the intervention group. Control and intervention groups did not vary significantly in terms of baseline characteristics except for bypass time. After adjusting for all baseline variables, there was no statistically significant difference in the increase in serum creatinine between the control and the intervention groups (0.01 [95% CI: -0.03, 0.05], p = 0.545). CONCLUSIONS: This single-center, retrospective, cohort study found no change in the incidence and severity of postoperative AKI after the administration of nitric oxide into the cardiopulmonary bypass circuit in children.

Incidence and predictors of epilepsy in children with congenital heart disease.

OBJECTIVE: Children with CHD may be at increased risk for epilepsy. While the incidence of perioperative seizures after surgical repair of CHD has been well-described, the incidence of epilepsy is less well-defined. We aim to determine the incidence and predictors of epilepsy in patients with CHD. METHODS: Retrospective cohort study of patients with CHD who underwent cardiopulmonary bypass at <2 years of age between January, 2012 and December, 2013 and had at least 2 years of follow-up. Clinical variables were extracted from a cardiac surgery database and hospital records. Seizures were defined as acute if they occurred within 7 days after an inciting event. Epilepsy was defined based on the International League Against Epilepsy criteria. RESULTS: Two-hundred and twenty-one patients were identified, 157 of whom were included in our analysis. Five patients (3.2%) developed epilepsy. Acute seizures occurred in 12 (7.7%) patients, only one of whom developed epilepsy. Predictors of epilepsy included an earlier gestational age, a lower birth weight, a greater number of cardiac surgeries, a need for extracorporeal membrane oxygenation or a left ventricular assist device, arterial ischaemic stroke, and a longer hospital length of stay. CONCLUSIONS: Epilepsy in children with CHD is rare. The mechanism of epileptogenesis in these patients may be the result of a complex interaction of patient-specific factors, some of which may be present even before surgery. Larger long-term follow-up studies are needed to identify risk factors associated with epilepsy in these patients.

Periocardiophrenic Release to Prevent Conduit Compression After Neonatal Truncus Arteriosus Repair.

Sternal approximation postcardiac surgery in neonates can sometimes be challenging. Neonatal truncus arteriosus repair using a right ventricle-to-pulmonary artery homograft conduit is one such surgical procedure wherein there is a risk of developing conduit compression after sternal closure. We describe our technique of pericardiophrenic release at the time of delayed sternal closure to prevent hemodynamic compromise and conduit compression after sternal approximation in such cases.

Repeat Extracorporeal Membrane Oxygenation Support Is Appropriate in Selected Children With Cardiac Disease: An Extracorporeal Life Support Organization Study.

OBJECTIVE: Children requiring multiple consecutive extracorporeal membrane oxygenation (ECMO) runs likely have ongoing cardiac pathology (eg, residual lesions, myocardial dysfunction) and are exposed to increased complications and end-organ failure. Often, repeat back-to-back ECMO is suggested to be futile due to poor reported survival. METHODS: Using Extracorporeal Life Support Organization (ELSO) data (2011-2019), we evaluated children (n = 669) who received multiple cardiac ECMO runs (≥2) within 30 days interval. Factors associated with hospital mortality were evaluated using multivariable regression analysis. RESULTS: Median ECMO runs was 2 (range: 2-5) including 294 (44%) patients who received extracorporeal cardiopulmonary resuscitation (ECPR). There were 250 (37%) hospital survivors. Survivors were more likely older, Caucasian, and less likely to have hypoplastic left heart syndrome, require >2 runs, receive longer support duration, require inotropes or have acidosis while on ECMO, or develop renal and neurological complications. On multivariable analysis, factors associated with death included neonates (odds ratio [OR] = 3.6, 95% CI = 1.8-7.5, P = .0002), African Americans (OR = 2.7, 95% CI = 1.4-4.9, P = .0307), longer ECMO duration (OR = 1.1, 95% CI = 1.05-1.11, P < .0001, per 10 hours), central cannulation at initial run (OR = 1.7, 95% CI = 1.1-2.8, P = .0285), renal failure (OR = 3.0, 95% CI = 1.9-4.6, P < .0001), and neurological complications (OR = 3.8, 95% CI = 2.2-6.8, P < .0001). CONCLUSIONS: In selected children with cardiac pathology, multiple back-to-back ECMO and/or ECPR runs are associated with 37% hospital survival. Although registry data limit the ability to clearly determine selection criteria for repeat ECMO, our findings suggest that in properly selected patients, repeat ECMO support is not futile. Ongoing assessment of support adequacy, end-organ function, and cardiopulmonary recovery is necessary as longer support and emerging complications are associated with poor survival.

Interposition Technique for Pulmonary Valve Replacement.

BACKGROUND: Stented bioprosthesis implant at surgical pulmonary valve replacement (PVR) ideally should be 25 to 27 mm to facilitate future percutaneous PVR. This often requires accommodating 35 to 37 mm diameter sewing ring in the pulmonary position and requires anterior patch augmentation of the right ventricular outflow tract (RVOT). We present a novel "interposition" technique of PVR that allows upsizing the valve without RVOT patch augmentation. METHODS: Using standard cardiopulmonary bypass, the main pulmonary artery (MPA) is dissected and transected at an appropriate level. The remnants of pulmonary valve leaflets are excised. The valve stent posts are telescoped into distal MPA, the MPA continuity is restored by end-to-end anastomosis of the proximal and distal MPA, with the interposed prosthetic valve sewing ring in the suture line between the two edges of the MPA with the bulk of the sewing ring extravascular. RESULT: A total of seven patients (tetralogy of Fallot, three; congenital pulmonary stenosis, four; age range: 15-33 years) underwent the procedure. No patient required RVOT patch augmentation, all patients were extubated in the operating room and were fast-tracked to recovery. Our proposed technique of PVR has the following advantages: accommodate larger size valve, eliminates risk of a paravalvar leak, coronary compression, and anterior tilting of the prosthesis. CONCLUSION: The valve interposition technique avoids the need for RVOT patch, allows implantation of an adequate sized prosthetic valve, maintains native geometry of the pulmonary artery without the risk of tilting of the prosthesis, and eliminates the risk of paravalvular regurgitation and left coronary compression.