Search

Sternal approximation post-cardiac 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 pericardio-phrenic release at the time of delayed sternal closure to prevent hemodynamic compromise and conduit compression after sternal approximation in such cases.

Neurologic impairments are a significant concern for survivors after pediatric cardiac surgery with cardiopulmonary bypass (CPB). We have previously shown that mesenchymal stromal cell (MSC) delivery through CPB has the potential to mitigate the effects of CPB on neural stem/progenitor cells. This study assessed the dose effects of MSCs.Piglets (n = 20) were randomly assigned to 1 of 4 groups: control, CPB, or CPB followed by MSC administration with low and high doses (10 × 10By magnetic resonance imaging, approximately 10 times more MSCs were detected within the entire brain after high-dose delivery than after low-dose delivery. No adverse events affecting hemodynamics, various biomarkers, and neuroimaging were detected after high-dose MSC delivery. High-dose MSCs significantly increased circulating levels of interleukin 4 after CPB. Both MSC groups normalized microglia activation after CPB, demonstrating MSC-induced reduction in cerebral inflammation. There was a significant increase in neuroblasts in the subventricular zone in both treatment groups. The thickness of the most active neurogenic area within the subventricular zone was significantly increased after high-dose treatment compared with CPB and low-dose MSCs, suggesting dose-dependent effects on the neurogenic niche.MSC delivery through CPB is feasible up to 100 × 10

The Yasui operation is indicated in an interrupted aortic arch and a posterior malaligned ventricular septal defect with a narrow subaortic region. We present a modification of the Yasui procedure in which the aortic reconstruction was simplified using a nonvalved cryopreserved femoral vein homograft to connect the pulmonary artery to the descending aorta. A side-to-side anastomosis was performed between the femoral vein homograft and ascending aorta to complete the neoaortic reconstruction. After baffling the left ventricle to the pulmonary artery with a patch, a valved segment from the same femoral vein homograft was used to restore continuity of the right ventricular outflow.

Background The Society of Thoracic Surgeons Congenital Heart Surgery Database Mortality Risk Model adjusts not only for procedure and age group pairings but also for additional patient factors, including the binary presence or absence of a chromosomal abnormality (CA), syndrome (S), and/or a noncardiac congenital anatomic abnormality (NCAA). This analysis refines case-mix adjustment by adding more granular adjustment for individual conditions (CA, S, and NCAA), consistent with a hypothesis that associated risk of mortality differs between individual conditions. Methods CA/S corresponding to the same condition were merged to a single condition code. Odds ratios were estimated for all CA/S. For CA/S associated with at least 10 deaths in neonates and infants and at least 10 deaths in children and adults, odds ratios were estimated for the effect of the CA/S separately in neonates/infants and in children/adults. In addition to these condition/age interactions, condition/age/procedure interactions were explored (eg, effect of Down syndrome was estimated based on age and procedure subgroups, including atrioventricular canal repair and single-ventricle palliation). Bayesian modeling was used to create 5 maximally homogeneous groups of CA/S from 81 candidate CA/S variables. A standard logistic regression model then incorporated indicator variables for the 5 categories of CAs/Ss, 7 unique NCAAs, and all other covariates in the previously published Society of Thoracic Surgeons Congenital Heart Surgery Database Mortality Model. Results Analysis included 107,062 operations in 100 centers (2010 to 2015). Operative Mortality was 3,629 (3.4%). In the development sample, the C statistics of the original nonaugmented model and the augmented model were 0.872 and 0.875, respectively. Conclusions The Society of Thoracic Surgeons Congenital Heart Surgery Database Mortality Risk Model has been augmented by addition of covariates representing individual CAs, Ss, and NCAAs.

The Society of Thoracic Surgeons Congenital Heart Surgery Database is the largest congenital and pediatric cardiac surgical clinical data registry in the world. It is the platform for all activities of The Society of Thoracic Surgeons related to the analysis of outcomes and the improvement of quality in this subspecialty. This report summarizes current aggregate national outcomes in congenital and pediatric cardiac surgery and reviews related activities in the areas of quality measurement, performance improvement, and transparency. The reported data about aggregate national outcomes are exemplified by an analysis of 10 benchmark operations performed from January 2012 to December 2015. This analysis documents the overall aggregate operative mortality (interquartile range among all participating programs) for the following procedural groups: off-bypass coarctation repair, 1.3% (0.0% to 1.8%); ventricular septal defect repair, 0.6% (0.0% to 0.9%); tetralogy of Fallot repair, 1.1% (0.0% to 1.4%); complete atrioventricular canal repair, 3.0% (0.0% to 4.7%); arterial switch operation, 2.7% (0.0% to 4.1%); arterial switch operation and ventricular septal defect repair, 5.3% (0.0% to 6.7%); Glenn/hemi-Fontan, 2.5% (0.0% to 4.5%); Fontan operation, 1.2% (0.0% to 1.2%); truncus arteriosus repair, 9.4% (0.0% to 16.7%); and Norwood procedure, 15.7% (8.9% to 25.0%).

Background We have previously shown that early primary repair of tetralogy of Fallot can be performed without increased morbidity or resource utilization. The technical performance score (TPS) is a self-assessment tool used to identify patients at risk of poor postoperative outcomes. We hypothesized that adequate technical repair can be obtained regardless of the patient's preoperative age or size. Methods A retrospective review of all tetralogy of Fallot patients repaired between September 2004 and December 2013 was performed. The postoperative predischarge echocardiogram was reviewed to assign a TPS rating of optimal, adequate, or inadequate. The TPS groups were compared by univariate analysis using the Kruskal-Wallis test for continuous variables and χ 2 analysis for categoric variables. Multivariable logistic regression analysis was performed to identify independent predictors of inadequate TPS. Results Among 167 patients (1 operative mortality), TPS was optimal in 88, adequate in 62, and inadequate in 17. Patients with worse TPS had longer ventilation time ( p = 0.031), hospital length of stay ( p = 0.036), and higher hospital charges ( p = 0.005). Multivariable regression analysis revealed discontinuous branch pulmonary arteries (odds ratio 18.24, 95% confidence interval: 1.42 to 234, p = 0.015) as the only independent predictor of inadequate TPS. Younger age at repair ( p = 0.245) and smaller weight ( p = 0.260) were not associated with inadequate TPS. Conclusions Technical adequacy of tetralogy of Fallot repair is affected by anatomic subsets (discontinuous branch pulmonary arteries) and not by the patient's age or size. Worse TPS is associated with higher postoperative morbidity and hospital charges. Younger age and size should not be a deterrent for early primary repair.

The intra-extracardiac (IE) Fontan modification has advantages over the lateral tunnel modification. A direct comparison of IE to the extracardiac (EC) modification so far has not been done. This study compared IE to EC Fontan with respect to early postoperative outcomes.We retrospectively compared outcomes of the Fontan operation using the IE or EC conduit modification between January 2012 and December 2016. IE and EC groups were compared using univariate and multivariable regression analysis. To eliminate the confounding effects of fenestration, repeat intergroup comparison was performed after excluding nonfenestrated patients.There were 81 patients grouped according to Fontan modification into the IE group (n = 43) or EC group (n = 38). The Fontan was fenestrated in 100% of the IE group but in only 55% of the EC group (p0.001). Cardiopulmonary bypass time was shorter for the IE group (74 vs 103, p0.001) The IE patients had median cross-clamp time of 34 minutes, whereas only 2 patients in the EC group required cross-clamping (35 and 95 minutes; p0.001). The IE group had significantly shorter median duration of pleural effusion (8 days vs 11 days, p = 0.007) and hospital length of stay (9 days vs 13 days, p = 0.001) than the EC group. Multivariable linear regression analysis revealed that the IE modification was independently associated with reduced duration of pleural effusion (p = 0.004) and hospital length of stay (p = 0.003). Presence of any unfavorable hemodynamics on preoperative assessment was also associated with longer duration of pleural effusion and hospital length of stay for patients with fenestration.The IE Fontan modification may be associated with reduced duration of postoperative pleural effusion and hospital length of stay compared with the EC modification.

Background White matter (WM) injury is common after neonatal cardiopulmonary bypass (CPB). We have demonstrated that the inflammatory response to CPB is an important mechanism of WM injury. Microglia are brain-specific immune cells that respond to inflammation and can exacerbate injury. We hypothesized that microglia activation contributes to WM injury caused by CPB. Methods Juvenile piglets were randomly assigned to 1 of 3 CPB-induced brain insults (1, no-CPB; 2, full-flow CPB; 3, CPB and circulatory arrest). Neurobehavioral tests were performed. Animals were sacrificed 3 days or 4 weeks postoperatively. Microglia and proliferating cells were immunohistologically identified. Seven analyzed WM regions were further categorized into 3 fiber connections (1, commissural; 2, projection; 3, association fibers). Results Microglia numbers significantly increased on day 3 after CPB and circulatory arrest, but not after full-flow CPB. Fiber categories did not affect these changes. On post-CPB week 4, proliferating cell number, blood leukocyte number, interleukin (IL)-6 levels, and neurologic scores had normalized. However, both full-flow CPB and CPB and circulatory arrest displayed significant increases in the microglia number compared with control. Thus brain-specific inflammation after CPB persists despite no changes in systemic biomarkers. Microglia number was significantly different among fiber categories, being highest in association and lowest in commissural connections. Thus there was a WM fiber-dependent microglia reaction to CPB. Conclusions This study demonstrates prolonged microglia activation in WM after CPB. This brain-specific inflammatory response is systemically silent. It is connection fiber-dependent which may impact specific connectivity deficits observed after CPB. Controlling microglia activation after CPB is a potential therapeutic intervention to limit neurologic deficits after CPB.

Background Extracorporeal membrane oxygenation (ECMO) support is often required in the management of perioperative congenital heart surgery (CHS) patients. However, 24-hour in-hospital congenital cardiac surgical coverage (24-CCSC) is not available at all institutions. The purpose of this study is to evaluate the effect of 24-CCSC on perioperative ECMO outcomes in CHS patients. Methods An institutional review board approved, retrospective review of 128 perioperative CHS ECMO patients at a single, quaternary care children's hospital between January 2003 and December 2012 was performed. Primary endpoints evaluated were mortality in children supported with ECMO after undergoing cardiac surgery and ECMO-related morbidity after initiation of 24-CCSC with advanced congenital cardiac surgical fellows. Patients were divided into 2 groups based on whether 24-CCSC was absent (cohort 1: January 2003 to July 2007) or present (cohort 2: August 2007 to December 2012) at the time of ECMO management. Results The surgical procedures performed were similar in both cohorts based on STAT Mortality Categories (5 Society of Thoracic Surgeons-European Association for Cardio-Thoracic Surgery Congenital Heart Surgery Mortality Categories). The overall mortality rate in children supported with ECMO after undergoing cardiac surgery was 53%. This mortality was significantly reduced from 68% to 43% ( p = 0.007) with 24-CCSC. Multivariate logistic regression analysis revealed that 24-CCSC ( p = 0.009) and lower STAT Mortality Category ( p = 0.042) were independent predictors of operative survival. Cardiac arrhythmias (36% to 16%; p = 0.012) and pulmonary complications (32% to 8%; p Conclusions The presence of 24-CCSC significantly decreased the rate of mortality in children supported with ECMO after undergoing cardiac surgery, as well as cardiac arrhythmias and pulmonary complications for perioperative CHS patients receiving ECMO support. This study demonstrates that CHS programs would benefit from 24-CCSC in the care of this critically ill patient population.

Although early primary repair of tetralogy of Fallot has gained wider acceptance, there is some speculation that repair at a younger age may be associated with increased morbidity and resource utilization.A retrospective review of all consecutive patients undergoing tetralogy of Fallot repair between September 2004 and December 2011 was performed. Primary end points were hospital charges, and surrogates of postoperative hospital resource utilization, including ventilation time, intensive care unit (ICU) stay, and hospital stay. The secondary end point was operative death. Logistic regression analysis was used to determine factors associated with increased postoperative hospital resource utilization.Among 164 patients in the study, there was 1 hospital death (0.6%). After excluding 9 patients who had palliative procedures before their repair, 155 comprised the primary repair group. Multivariate linear regression analysis revealed prematurity (p = 0.018), a nonelective operation (p0.001), and major extracardiac anomalies (p = 0.003) were independent predictors of increased postoperative hospital charges. Prematurity (p0.002), low birth weight (p = 0.047), and major extracardiac anomalies (p0.001) were significant predictors of increased ventilation time. Prematurity (p0.001), a nonelective operation (p0.001), and low birth weight (p = 0.048) significantly increased ICU length of stay. A nonelective operation (p = 0.025) and major extracardiac anomalies (p0.001) were predictors of an increased hospital stay. Younger age at repair was not associated with any increase in ventilation time, ICU stay, hospital stay, or with an increase in hospital charges.Extracardiac anomalies, prematurity, low birth weight, and nonelective surgical intervention are predictors of increased morbidity and increased hospital resource utilization and impose a significant cost burden to the care of these patients. Early primary repair of tetralogy of Fallot can be safely performed without any increase in morbidity or increased hospital resource utilization.

A 5-year-old boy was found to have a congenital left ventricular outflow tract (LVOT) aneurysm of the intervalvular fibrosa, LVOT obstruction after repair of a perimembranous ventricular septal defect, and aortic coarctation. The patient underwent successful plication of the aneurysm, resection of the fibrous subaortic stenosis, and septal myectomy.

We have previously demonstrated that early primary repair of tetralogy of Fallot with pulmonary stenosis (TOF) can be safely performed without increase in hospital resource utilization or compromise to surgical technical performance scores (TPS). We sought to identify the optimal timing for elective early primary repair of TOF with respect to intermediate-term reintervention.Retrospective review of all patients with TOF undergoing elective primary repair between September 2004 and December 2013 was performed. Patients were stratified into reintervention group or no reintervention group. Multivariable Cox regression analysis identified independent predictors of reintervention. Youden's J-index in receiver operating characteristic analysis identified optimal age cutoff predictive of reintervention. Kaplan-Meier analysis with the log-rank test compared reintervention rates stratified by age and TPS.A total of 129 patients with median (interquartile range) age and weight of 78 days (56 to 111) and 5 kg (4.1 to 5.7), respectively, underwent primary repair. After a median (interquartile range) follow-up of 2.3 years (0.1 to 4.6), 18 patients (14%) required a total of 22 reinterventions. Youden's J-index revealed significantly lower risk of intermediate-term reintervention when repaired after 55 days of age (8% for55 days old versus 31% for ≤55 days of age). Multivariable Cox regression identified age 55 days and younger (hazard ratio [HR] 4.5, 95% confidence interval [CI] 1.6 to 12.8, p = 0.004), valve sparing repair (HR 15.3, 95% CI 1.8 to 128.5, p0.001), residual right ventricular outflow tract (RVOT) gradient (HR 1.11, 95% CI 1.1 to 1.2, p0.001), and inadequate TPS (HR 21.5, 95% CI 7.4 to 63, p0.001) as independent predictors of overall intermediate-term reintervention.Elective repair in patients greater than 55 days of age, irrespective of size of the patient, can be safely performed without any increase in reintervention rates. Both residual peak RVOT gradient and TPS are effective in identifying patients at increased risk of reintervention.

The Society of Thoracic Surgeons Congenital Heart Surgery Database is the largest congenital and pediatric cardiac surgical clinical data registry in the world. It is the platform for all activities of The Society of Thoracic Surgeons related to the analysis of outcomes and the improvement of quality in this subspecialty. This article summarizes current aggregate national outcomes in congenital and pediatric cardiac surgery and reviews related activities in the areas of quality measurement, performance improvement, and transparency. The reported data about aggregate national outcomes are exemplified by an analysis of 10 benchmark operations performed from January 2011 to December 2014 and documenting overall discharge mortality (interquartile range among programs with more than 9 cases): off-bypass coarctation, 1.0% (0.0% to 0.9%); ventricular septal defect repair, 0.7% (0.0% to 1.1%); tetralogy of Fallot repair, 1.0% (0.0% to 1.7%); complete atrioventricular canal repair, 3.2% (0.0% to 6.5%); arterial switch operation, 2.7% (0.0% to 5.6%); arterial switch operation plus ventricular septal defect, 5.3% (0.0% to 6.7%); Glenn/hemiFontan, 2.1% (0.0% to 3.8%); Fontan operation, 1.4% (0.0% to 2.4%); truncus arteriosus repair, 9.6% (0.0 % to 11.8%); and Norwood procedure, 15.6% (10.0% to 21.4%).

The integrity of the blood brain barrier (BBB) after cardiopulmonary bypass (CPB) with hypothermic circulatory arrest (HCA) is controversial in children. We tested the hypothesis that the BBB is disrupted by HCA.Forty-one piglets (mean weight 11 kg) were randomly allocated to acute and survival experiments. Five groups (25 piglets, 5 per group) underwent acute studies: anesthesia alone (control); CPB at 37°C with full-flow (FF); CPB at 25°C with very low flow (LF); HCA at 15°C, and HCA at 25°C. Two groups (16 piglets, 8 per group) underwent survival studies: CPB at 25°C with LF and HCA. In the acute studies, Evans blue dye (EBD) extravasation through the BBB into the brain was measured using two methods: EBD absorbance of homogenized brain, and immunohistochemical localization of EBD-linked albumin for cortex, caudate nucleus, thalamus, hippocampus, and cerebellum. In the survival studies, cerebral histology was assessed with hematoxylin-eosin stain after sacrifice at 4 days after surgery.The BBB disruption was clearly observed around watershed areas for 25°C HCA compared with other conditions. Microscopic data showed that leakage of EBD in 25°C HCA was more severe than control in all brain areas (p0.05), and EBD and albumin were colocalizing. Histologic damage scores were significantly higher in watershed areas with 25°C HCA.The BBB was impaired around watershed areas by 25°C HCA for 1 hour according to both macroscopic and microscopic data. An increase in permeability of the BBB may be both a sign and a mechanism of brain damage.

Information from clinical studies is limited regarding the optimal method for myocardial protection in immature hearts, and specifically the benefits of different cardioplegia (CP) formulations. We compared two CP techniques by evaluation of the cardiac index using thermodilution catheters.The study cohort includes 102 neonates and infants (aged 2 to 269 days) undergoing biventricular repair surgery. A total of 52 patients were managed with commercially available crystalloid CP ("standard CP") and 50 had a custom mix of crystalloid CP with dilute blood ("custom CP"). Repeated-measures analysis of variance was applied to compare the cardiac index every 3 hours during the 24-hour postoperative period between the two groups and stratified by diagnosis. Adjustment for possible confounders was used to more objectively compare the groups.Standard crystalloid CP provided superior myocardial protection in patients who had transposition of great arteries (p0.001), and this advantage held after adjusting for age and cross-clamp time. Shorter ventilatory times and intensive care unit stays were also noted for the standard CP group (p = 0.01). Cardiac index after cardiopulmonary bypass was lower in patients who had transposition of great arteries and intact ventricular septum compared with the group who had transposition of great arteries and ventricular septal defect; and in both subgroups, the standard CP technique was superior to the custom CP solution. Age at operation was inversely correlated with the cardiac index.Younger patients, particularly neonates, have a significantly higher postoperative cardiac index with standard CP than with custom CP. The advantage is not apparent beyond the neonatal period.

Background The empirically derived 2014 Society of Thoracic Surgeons Congenital Heart Surgery Database Mortality Risk Model incorporates adjustment for procedure type and patient-specific factors. The purpose of this report is to describe this model and its application in the assessment of variation in outcomes across centers. Methods All index cardiac operations in The Society of Thoracic Surgeons Congenital Heart Surgery Database (January 1, 2010, to December 31, 2013) were eligible for inclusion. Isolated patent ductus arteriosus closures in patients weighing less than or equal to 2.5 kg were excluded, as were centers with more than 10% missing data and patients with missing data for key variables. The model includes the following covariates: primary procedure, age, any prior cardiovascular operation, any noncardiac abnormality, any chromosomal abnormality or syndrome, important preoperative factors (mechanical circulatory support, shock persisting at time of operation, mechanical ventilation, renal failure requiring dialysis or renal dysfunction (or both), and neurological deficit), any other preoperative factor, prematurity (neonates and infants), and weight (neonates and infants). Variation across centers was assessed. Centers for which the 95% confidence interval for the observed-to-expected mortality ratio does not include unity are identified as lower-performing or higher-performing programs with respect to operative mortality. Results Included were 52,224 operations from 86 centers. Overall discharge mortality was 3.7% (1,931 of 52,224). Discharge mortality by age category was neonates, 10.1% (1,129 of 11,144); infants, 3.0% (564 of 18,554), children, 0.9% (167 of 18,407), and adults, 1.7% (71 of 4,119). For all patients, 12 of 86 centers (14%) were lower-performing programs, 67 (78%) were not outliers, and 7 (8%) were higher-performing programs. Conclusions The 2014 Society of Thoracic Surgeons Congenital Heart Surgery Database Mortality Risk Model facilitates description of outcomes (mortality) adjusted for procedural and for patient-level factors. Identification of low-performing and high-performing programs may be useful in facilitating quality improvement efforts.

The purpose of this study is to define a safe minimum flow rate for specific bypass conditions using continuous monitoring with near-infrared spectroscopy and direct observation of the cerebral microcirculation.Two series of experiments (n = 72 in each) were conducted in which piglets were cooled to a temperature of 15 degrees, 25 degrees, or 34 degrees C on cardiopulmonary bypass with hematocrit 20% or 30%, pH-stat management in all, followed by 1 or 2 hours of reduced flow (10, 25, or 50 mL.kg(-1).min(-1)). Animals in series one had a cranial window placed over the parietal cortex to evaluate the microcirculation with intravital microscopy. Plasma was labeled with fluorescein-isothiocyanate-dextran for assessment of functional capillary density (FCD) and microvascular diameter. In series two, near-infrared spectroscopy was utilized to detect tissue oxygenation index (TOI). Outcome measures included histologic and neurologic injury scores.The TOI during low flow and FCD during rewarming and after weaning from cardiopulmonary bypass were associated with neurologic injury. Failure of FCD to return to baseline during rewarming predicted worse functional and histologic outcome (p0.001). Regression analysis indicated that temperature and low-flow rate were multivariable predictors of TOI and FCD during rewarming (p0.001).Tissue oxygen index derived from near-infrared spectroscopy is a useful real-time monitor for detecting inadequate cerebral perfusion during cardiopulmonary bypass. Minimal safe pump flow rate varies according to the conditions of bypass: using pH stat management and with an hematocrit of either 20% or 30%, a flow rate as low as 10 mL.kg(-1).min(-1) is safe for as long as 2 hours at a temperature of 15 degrees C. However, under the same conditions at 34 degrees C, a flow rate of 10 mL.kg(-1).min(-1) is very likely to be associated with neurologic injury.

Repair of total anomalous pulmonary venous connection (TAPVC) continues to be associated with significant mortality. We reviewed patients undergoing consecutive TAPVC repairs over a 10-year period at Children's Hospital Boston. The impact of current surgical and perioperative management strategies on short-term outcomes (postrepair pulmonary venous obstruction and mortality) is evaluated.All patients with surgically corrected TAPVC from November 1989 to December 2000 were included. Charts were reviewed for patient demographics, operation variables, and postoperative course.There were 123 patients in the cohort, of which 72 (59%) were male. The median age and weight at operation were 10 days and 3.6 kg, respectively. Sixty-eight (55%) patients presented with pulmonary venous obstruction, and 65 (53%) underwent emergent TAPVC repair. Thirty-nine (32%) had single-ventricle anatomy, and 84 (68%) had two-ventricle anatomy. Thirty patients (24%) died. Kaplan-Meier survival at 1 month was 65% (95% confidence interval [CI], 55% to 75%) for single-ventricle patients versus 90% (95% CI, 90% to 100%) for two-ventricle patients; at 36 months it was 47% (95% CI, 35% to 59%) versus 87% (95% CI, 81% to 93%), respectively. By Cox multivariable regression analysis, a single ventricle (p0.001, hazard ratio, 4.8; 95% CI, 2.5 to 9.2) was an independent mortality risk factor. Prerepair pulmonary venous obstruction was a multivariate risk factor for death among single-ventricle patients. Postrepair pulmonary venous obstruction occurred in 11%. If year of operation is used as a predictor, two-ventricle patient survival has significantly improved (p0.05).Despite current interventions, single-ventricle patients continue to have a worse prognosis than two-ventricle patients.

We present a hybrid technique of left ventricular assist device exclusion after bridge to recovery in a pediatric patient, using percutaneous occlusion of the outflow graft and surgical excision of driveline. This technique has the advantage of avoiding chest reentry and cardiopulmonary bypass.

Background Historically the Fontan operation in patients with single ventricle heterotaxy syndrome and atrial isomerism has been associated with high mortality. We studied whether recent modifications of the surgical technique have improved outcome. Methods A retrospective review of 135 patients with heterotaxy syndrome who underwent a Fontan operation between 1981 and 2000 was performed. Results There were 93 patients with right isomerism and 42 with left isomerism. Anomalies of venous return included 25 patients with extracardiac pulmonary venous connection (19%) and 37 patients with an interrupted inferior vena cava (27%). Thirty-six patients (27%) had at least moderate atrioventricular valve regurgitation. The type of Fontan procedure included 17 patients with an atriopulmonary Fontan connection, 67 with a lateral tunnel modification, 19 with an intraatrial tube graft, 25 with an extracardiac tubegraft, and 7 with an intra-extra atrial tube graft. A fenestration was placed in 93 patients (78%). Early mortality was 19% before 1991, 3% since 1991, and no patient has died early since 1993. Ten-year survivals were 70% for Fontan operations before 1990 and 93% for Fontan operations after 1990. Thirty-two patients (23%) had prolonged pleural effusions. Risk factors for death included anomalous pulmonary venous connection ( p = 0.02) and higher preoperative pulmonary vascular resistance ( p = 0.002). Sixty-two patients (47%) had some form of early postoperative arrhythmia. At 10 years, freedom from late bradyarrhythmia and late tachyarrhythmia were 78% and 70%, respectively. Preoperative arrhythmias, older age at operation, and anatomic features were each independent predictors of late arrhythmia. Conclusions The Fontan operation can now be performed in patients with heterotaxy syndrome with excellent survival. However, morbidity in terms of postoperative arrhythmias and prolonged pleural effusions remains significant. Fontan staging, appropriate choice of Fontan modification, aggressive treatment of concomitant malformations, and use of a baffle fenestration contribute to improved outcome.

Background . Patients with absent pulmonary valve syndrome (APVS) with respiratory distress (RD) have previously had a high mortality. In 1990 we adopted a strategy of primary repair including total replacement of the aneurysmal central pulmonary arteries (PAs) for patients with RD. Methods . Retrospective review was made of 54 consecutive patients with APVS between 1960 and 1998. Median age and weight were 4 months and 4.8 kg. RD was present in 23 patients (10 neonates, 16 required ventilation). Fifteen patients had repair with homograft replacement of the PAs and VSD closure (group 1). Twenty-seven patients had transannular patch with VSD closure with PA-plasty (group 2, n=21) or without PA plasty (group 3, n=6). Twelve had miscellaneous procedures (group 4); in 6 the VSD was left open. Results . Operative, 1-, 5-, and 10-year survivals were 83%, 80%, 78%, and 78%, respectively. Risk factors for operative mortality in multivariate analysis were RD ( p = 0.04), neonates ( p = 0.02), weight less than 3 kg ( p = 0.02), open VSD ( p = 0.02) and surgery before 1990 ( p = 0.04). Since 1990 operative mortality has decreased to 11% ( p = 0.04). RD was the only time-related predictor of survival in multivariate analysis ( p = 0.004). In patients with RD, survival with homograft was 73% versus 41% with other techniques ( p = 0.2). Mean follow-up was 72 ± 50 months. There were no significant differences in freedom from reintervention rates among the surgical groups ( p = 0.08). Conclusions . Aggressive homograft replacement of the central pulmonary arteries has been associated with improved survival in patients with APVS especially in neonates with severe RD.

The most common forms of risk adjustment for pediatric and congenital heart surgery used today are based mainly on the estimated risk of mortality of the primary procedure of the operation. The goals of this analysis were to assess the association of patient-specific preoperative factors with mortality and to determine which of these preoperative factors to include in future pediatric and congenital cardiac surgical risk models.All index cardiac operations in The Society of Thoracic Surgeons Congenital Heart Surgery Database (STS-CHSD) during 2010 through 2012 were eligible for inclusion. Patients weighing less than 2.5 kg undergoing patent ductus arteriosus closure were excluded. Centers with more than 10% missing data and patients with missing data for discharge mortality or other key variables were excluded. Rates of discharge mortality for patients with or without specific preoperative factors were assessed across age groups and were compared using Fisher's exact test.In all, 25,476 operations were included (overall discharge mortality 3.7%, n=943). The prevalence of common preoperative factors and their associations with discharge mortality were determined. Associations of the following preoperative factors with discharge mortality were all highly significant (p0.0001) for neonates, infants, and children: mechanical circulatory support, renal dysfunction, shock, and mechanical ventilation.Current STS-CHSD risk adjustment is based on estimated risk of mortality of the primary procedure of the operation as well as age, weight, and prematurity. The inclusion of additional patient-specific preoperative factors in risk models for pediatric and congenital cardiac surgery could lead to increased precision in predicting risk of operative mortality and comparison of observed to expected outcomes.

Background . Optimal management of double-outlet right ventricle with subpulmonary ventricular septal defect remains controversial. We reviewed our 7-year experience with patients who had this anatomic configuration. Methods . Between January 1992 and January 1999, 20 patients underwent an arterial switch operation (ASO group), and 12 underwent a bidirectional Glenn procedure followed by a modified Fontan in 10 (Glenn/Fontan). Mean follow-up was 23 ± 18 months. Results . An initial palliative operation was done in 19 patients (9 in the ASO group, 10 in the Glenn/Fontan group). There were no deaths in the Glenn/Fontan group. Four patients in the ASO group died within 33 days postoperatively. Two of them had a single coronary artery, 1 had a straddling mitral valve, 1 had a hypoplastic aortic arch, and 1 had multiple ventricular septal defects. Three patients had reoperation for subaortic stenosis (n = 2) or pulmonary stenosis (n = 1) after the ASO. Four patients (3 in the ASO group, 1 in the Glenn/Fontan) required a pacemaker for postoperative complete atrioventricular block. Actuarial survival at 5 years for the entire group was 87% (70% confidence interval, 81% to 93%). Conclusions . The ASO remains our preferred treatment for infants with double-outlet right ventricle and subpulmonary ventricular septal defect. However, associated anatomic defects are important risk factors.

Background . Near-infrared spectroscopy (NIRS) is used to monitor cerebral oxygenation during cardiac surgery. However, interpretation of the signals is controversial. The aim of the study was to determine which NIRS variable best correlated with brain damage as assessed by animal behavior and neurohistologic score and to compare the accuracy of NIRS and magnetic resonance spectroscopy (MRS) in predicting brain injury. Methods . Forty 5-week-old piglets underwent 60 minutes of deep hypothermic circulatory arrest (DHCA) at 15°C. Changes in brain adenosine triphosphate (ATP), phosphocreatine (PCr), and intracellular pH (pHi) were determined by MRS and correlated to changes in oxygenated hemoglobin (HbO 2 ), deoxygenated hemoglobin (Hb), and oxidized cytochrome a,a 3 (CytOx) NIRS signals. Brains were fixed on day 4 and examined using a neurohistologic score. Results . Reductions in CytOx and HbO 2 values were correlated closely with decreases in ATP, PCr, and pHi. The changes in CytOx and PCr showed the strongest correlation ( r = 0.623). Maximal CytOx reduction during DHCA of more than −25 μM ∗ differential pathlength factor (DPF) predicted brain damage with a sensitivity of 100% and a specificity of 75%. The histologic score was also correlated with a decrease in ATP ( r = −0.52 for CytOx; r = −0.32 for ATP); HbO 2 , PCr, and pHi showed no correlations. Conclusions . Reduction in CytOx correlates with decreased brain energy state and predicts histologic brain injury after DHCA with a high sensitivity. These data suggest that the level of CytOx could be a very important predictor of brain damage during DHCA.

Background . The present study examines the long-term outcome of pediatric patients with cardiac disease who required mechanical circulatory support with extracorporeal membrane oxygenation or ventricular assist devices. Methods . Telephone interviews and questionnaires were administered to parents and physicians of pediatric cardiac patients who were in-hospital survivors after requiring mechanical circulatory support, with either extracorporeal membrane oxygenation or ventricular assist devices. Data was collected regarding these patients' general health, cardiac status, and neurologic outcome, and compared between the two modes of support. Results . Follow-up was available for 26 patients supported with extracorporeal membrane oxygenation (25 survivors, 96%) and 11 patients supported with ventricular assist devices (10 survivors, 91%); median follow-up 42 months, 11 to 92 months). More than 80% of survivors were in New York Heart Association class I or II. Of 31 patients for whom neurologic assessment data was available, moderate to severe neurologic impairment was more common for extracorporeal membrane oxygenation supported patients [13 of 21, 59%) than for ventricular assist device supported patients (2 of 10, 20% p = 0.03). Neurologic impairment was associated with small patient size and the use of circulatory arrest during cardiac surgical repair, but was not associated with in-hospital neurologic complications, carotid cannulation, or presupport cardiac arrest. Conclusions . The long-term survival and cardiac functional status of pediatric cardiac patients requiring mechanical circulatory support is favorable. Extracorporeal membrane oxygenation supported patients demonstrate higher rates of neurologic impairment than patients supported with ventricular assist devices. Poor neurologic outcomes are associated with institution of support in younger patients with more complex congenital heart disease.

Background . Valved homograft conduit repair in neonates and young infants creates a physiologically normal biventricular circulation, and unlike shunts, avoids surgery on the branch pulmonary. Methods . Retrospective chart review was used for 84 patients operated on between 1990 and 1995 (mean age 26 ± 28 days, mean weight 3.3 ± 0.8 kg) undergoing homograft conduit repair in the first 3 months of life. Cases were divided into simple and complex, eg, absent pulmonary valve syndrome or associated interrupted arch. Mean homograft size was 9.0 ± 2 mm. Results . Early mortality was 4.7% (simple) and 30% (complex). Mean hospital stay was 18 days. Mean follow-up was 34 months. Thirty-seven (47%) patients underwent conduit replacement. Median time to reoperation was 3.1 years. Mean size of replacement homograft was 17 ± 2 mm. There were no deaths at reoperation. Mean hospital stay at conduit change was 6.3 days. Probability of survival at 5 years is 75%. Conclusions . Biventricular repair employing a conduit can be performed safely in noncomplex anomalies in the first 3 months of life. Time interval until repeat surgery is relatively short but equal or greater than that with most palliative procedures.

Background. Repair of anomalous origin of the left coronary artery from the pulmonary artery (ALCAPA) in infants carries a high operative risk, particularly in infants with myocardial infarction and poor left ventricular function. The marked recovery of left ventricular function reported late after repair, however, suggests that an aggressive approach to repair should be undertaken. Methods. Of 31 children undergoing primary repair of ALCAPA at our institution from 1987 to 1996, 26 were infants (6 weeks to 9 months old). All but 2 had severe left ventricular dysfunction, and 8 had moderate to severe mitral regurgitation. Seven children were unable to be weaned from cardiopulmonary bypass because of poor left ventricular function and elevated left atrial pressure. These 7 children were placed on mechanical left ventricular support using a centrifugal pump, with support ranging from 2.2 to 70.6 hours. Results. One child died shortly after the start of left ventricular assist (2.2 hours), and another died of arrhythmia within 24 hours after successful decannulation. All 5 survivors had significant improvement in left ventricular function, with 2 requiring late mitral valve repair. Conclusions. Infants with ALCAPA who have severe left ventricular dysfunction represent a higher risk group for repair. However, with use of mechanical circulatory support in those unable to be weaned from cardiopulmonary bypass, a high survival rate can be achieved with good long-term recovery. We conclude that an aggressive approach to early repair in all children with ALCAPA is warranted, regardless of the degree of left ventricular dysfunction.

Background . A recent study found that a higher-perfusate hematocrit was associated with improved neurologic recovery after deep hypothermic circulatory arrest. The current study examined the relative contributions of oxygen delivery and colloid oncotic pressure to this result, as well as the efficacy of different colloidal agents and modified ultrafiltration. Methods . Twenty-six piglets were randomized into five groups (n = 5 or 6 animals per group): control group 1—blood and crystalloid prime, hematocrit of 20%; group 2—blood and hetastarch prime, hematocrit of 20%; group 3—blood and pentafraction prime, hematocrit of 20%; group 4—blood and crystalloid prime with 10 minutes of modified ultrafiltration; group 5—whole blood prime, hematocrit of 30%. All groups underwent 60 minutes of deep hypothermic circulatory arrest at 15°C. Results . Groups 2 and 3 showed less body weight gain (analysis of variance, p = 0.001; group 2 versus group 1, p = 0.0009; group 3 versus group 1, p = 0.0009) and body water content after cardiopulmonary bypass (analysis of variance, p = 0.001; group 2 versus group 1, p = 0.003; group 3 versus group 1, p = 0.013). Group 5 showed more rapid recovery of phosphocreatine and intracellular acidosis, as measured by magnetic resonance spectroscopy, during rewarming than group 1 did (phosphocreatine, p = 0.0329; intracellular acidosis, p = 0.0462). Group 3 also showed accelerated recovery of intracellular acidosis ( p = 0.0411). Cytochrome a,a3 recovery, determined by near-infrared spectroscopy, was significantly better in group 5 than in group 1 and worse in group 2 than in group 1 after rewarming. The neurologic deficit score and overall performance category score were best in group 5 (neurologic deficit score, p = 0.012; overall performance category score, p = 0.046) on the first postoperative day. Group 3 also had a better overall performance category score than group 1 did ( p = 0.0068). Only group 1 and 2 animals showed histologic damage. Conclusions . Both higher hematocrit and higher colloid oncotic pressure with pentafraction improve cerebral recovery after deep hypothermic circulatory arrest. The higher hematocrit improves cerebral oxygen delivery but does not reduce total body edema. Modified ultrafiltration after cardiopulmonary bypass is less effective than having a higher initial prime hematocrit or colloid oncotic pressure.

The development of pulsatile ventricular assist devices for children has been limited mainly by size constraints. The purpose of this study was to evaluate the MEDOS trileaflet-valved, pulsatile, pediatric right ventricular assist device (stroke volume = 9 mL) in a neonatal lamb model of acute right ventricular failure.Right ventricular failure was induced in ten 3-week-old lambs (8.6 kg) by right ventriculotomy and disruption of the tricuspid valve. Control group 1 (n = 5) had no mechanical support whereas experimental group 2 (n = 5) had right ventricular assist device support for 6 hours. The following hemodynamic parameters were measured in all animals: heart rate and right atrial, pulmonary arterial, left atrial, and systemic arterial pressures. Cardiac output was measured by an electromagnetic flow probe placed on the pulmonary artery.All results are expressed as mean +/- standard deviation and analyzed by Student's t test. A p value less than 0.05 was considered statistically significant. Base-line measurements were not significantly different between groups and included systemic arterial pressure, 80.6 +/- 12.7 mm Hg; right atrial pressure, 4.6 +/- 1.6 mm Hg; mean pulmonary arterial pressure, 15.6 +/- 4.2 mm Hg; left atrial pressure, 4.8 +/- 0.8 mm Hg; and cardiac output, 1.4 +/- 0.2 L/min. Right ventricular injury produced hemodynamics compatible with right ventricular failure in both groups: mean systemic arterial pressure, 38.8 +/- 10.4 mm Hg; right atrial pressure, 16.8 +/- 2.3 mm Hg; left atrial pressure, 1.4 +/- 0.5 mm Hg; and cardiac output, 0.6 +/- 0.1 L/min. All group 1 animals died at a mean of 71.4 +/- 9.4 minutes after the operation. All group 2 animals survived the duration of study. Hemodynamic parameters were recorded at 2, 4, and 6 hours on and off pump, and were significantly improved at all time points: mean systemic arterial pressure, 68.0 +/- 13.0 mm Hg; right atrial pressure, 8.2 +/- 2.3 mm Hg; left atrial pressure, 6.4 +/- 2.1 mm Hg; and cardiac output, 1.0 +/- 0.2 L/min.The results demonstrate the successful creation of a right ventricular failure model and its salvage by a miniaturized, pulsatile right ventricular assist device. The small size of this device makes its use possible even in small neonates.

Background The management of tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collateral arteries is controversial because of the wide variability of pulmonary artery (PA) and major aortopulmonary collateral arteries morphology. Several different staged strategies have been used to promote growth of diminutive PA branches. We have preferred a right ventricular (RV)-PA homograft for symmetrical growth of the central PA branches. In this study we evaluated the success of this strategy. Methods Between 2006 and 2012, 23 patients with pulmonary atresia and diminutive PAs underwent RV-PA homograft implantation. Median age was 2 months (range, 4 days to 18 months), and median body weight was 5.1 kg (range, 1.7 to 8.5 kg). The type of homograft was aortic in 8, pulmonary in 6, and femoral vein in 9. The mean diameter of the homograft was 10.5 mm (range, 6 to 16 mm). All procedures were performed on cardiopulmonary bypass. The PA diameter was measured at the time of the operation and subsequent catheterization. Results The median size of the branch PA was 2.1 mm. In the 18 patients who had serial assessment of PA size, the right PA increased by 307% ± 184%, the left PA increased by 283% ± 139%, and the Nakata index increased from 28.8 ± 20.1 mm 2 /m 2 to 253 ± 96 mm 2 /m 2 during a median period of 347 days (range, 44 to 1,520 days). The PA growth ratio (PA growth in mm/mo) was similar between the right PA (0.42 ± 0.46 mm/mo) and the left PA (0.43 ± 0.47 mm/mo). There was no acute conduit failure. Seventeen patients required 28 percutaneous interventions for embolization of an aortopulmonary collateral or stenosis of the conduit or PA. There were no hospital deaths. Three patients died late after other procedures during a mean follow-up of 44.7 months. Twenty patients (87%) have undergone complete repair to date. Conclusions RV-PA homograft implantation can be performed in neonates and infants with minimal risk of acute occlusion. The RV-PA homograft promotes rapid and balanced growth of central pulmonary arteries leading to complete repair in most patients.

Background. In the first weeks of life there are important maturational changes in the central nervous system in many species in energy metabolism, synapse number, and concentration of neuronal excitatory receptors. Methods. Four groups of 10 piglets (aged 1, 2, 4, and 10 weeks) underwent 1 hour of deep hypothermic circulatory arrest at 15°C, with cooling and rewarming on cardiopulmonary bypass. Cerebral blood flow and metabolic rate measurements and electroencephalographic recordings were obtained from 5 animals per group. The remaining animals underwent cerebral magnetic resonance spectroscopy. Results. Preoperative cerebral blood flow and glucose consumption were higher at 4 and 10 weeks than at 1 and 2 weeks. Cerebral adenosine triphosphate content decreased more rapidly during deep hypothermic circulatory arrest at 4 and 10 weeks. Phosphocreatine recovery was greater at 30 minutes of reperfusion at 10 weeks compared with 1 week. Recovery of cerebral phosphocreatine/adenosine triphosphate ratio and intracellular pH was remarkably uniform at all ages. Latency to recovery of electroencephalographic activity decreased with increasing age ( p = 0.04). Conclusions. Differences in acute recovery of brain energy metabolism and electroencephalogram after cardiopulmonary bypass and 1 hour of deep hypothermic circulatory arrest in piglets between 1 and 10 weeks of age are small. Further studies are required to correlate these acute findings with subsequent neurologic outcome.

Background Previous acute studies in immature piglets at our institution have demonstrated improved recovery of cerebral blood flow, intracellular pH, and high-energy phosphates with the administration of multidose University of Wisconsin solution as cerebroplegia during a period of deep hypothermic circulatory arrest (HCA). In an effort to define further the clinical applicability of this technique, we have developed a survival model of swine cardiopulmonary bypass (CPB) and HCA. Methods 12 Yorkshire pigs (age 4 to 5 weeks) were placed on CPB via the right femoral artery and right atrium. Animals were cooled to a rectal temperature of 15 °C and submitted to 90 minutes of HCA. Group UW (n = 6) received a single infusion of 50 mL/kg of 4 °C University of Wisconsin solution delivered antegrade to the cerebral circulation. The control group (n = 6) received no intervention. Animals were reperfused, rewarmed to 35 °C, and weaned from CPB. Neurologic assessments using neurologic deficit scoring (0 = normal, 500=brain death) and overall performance categories (1 = normal, 5=brain death) were performed at 24-hour intervals for 5 days. On the 5th postoperative day all brains were perfusion-fixed and examined for histologic evidence of neuronal injury (0 = normal, 5=severe injury). Results All animals were extubated 18 to 20 hours postoperatively. There was no significant difference between the mean neurologic score of the two groups. The mean day 5 neurologic deficit score was 108 for the UW group and 68 for the control group ( p > 0.05). The day 5 overall performance category was 2.8 for the UW group and 2.0 for the control group ( p > 0.05). Three of the UW animals but none of the control animals experienced generalized seizures. Histologic examination revealed more severe damage in UW animals, primarily in the cerebral cortex. Injury was more widespread in UW animals, involving cerebellum and hippocampus. The mean histologic injury score was 3.8 for UW animals and 2.4 for the control group ( p = 0.06). Conclusions A clinically relevant survival model of CPB with HCA in immature swine is feasible. Cold UW solution as single-dose cerebroplegia is not beneficial, and may be injurious to the immature swine brain subjected to CPB and HCA. Further studies are indicated to determine optimal composition and administration of cerebroplegic solutions.

Cerebral protection during deep hypothermic circulatory arrest is predicted on efficient and complete cerebral cooling. Institutions approach cooling quite differently. We compared two different cooling strategies in terms of measured jugular venous bulb saturations in 39 infants undergoing deep hypothermic cardiopulmonary bypass to evaluate the effect of institutional cooling practices on jugular venous bulb saturation, an indirect measure of cerebral cooling efficiency.The patients were grouped based on the method of core cooling. In group A (n = 17), core cooling was achieved rapidly by setting the water bath temperature of the heat exchanger at 4 degrees to 5 degrees C, and the patient was cooled until rectal temperature and nasopharyngeal temperature were 15 degrees C or lower. In group B (n = 22), the heat exchanger was initially set at 18 degrees C and slowly lowered to 12 degrees C. Hypothermic temperatures of 12 degrees C were maintained until the nasopharyngeal temperature was 18 degrees C or less and the rectal temperature was 20 degrees C or lower. Once cooling was complete, blood samples were analyzed by cooximetry for determination of arterial oxygen saturation and jugular venous bulb saturation.In group A, the measured jugular venous bulb saturation was 98.0% +/- 0.9% and the oxygen saturation to jugular venous bulb saturation difference was 0.3% +/- 0.5%, measured at the time that institutional cooling objectives were achieved (total cooling time, 15.0 +/- 0.45 minutes). In group B, jugular venous bulb saturation was 86.2% +/- 12% and the oxygen saturation to jugular venous bulb saturation difference was 10.8% +/- 12.2%, measured at the time that institutional cooling objectives were achieved (total cooling time, 17.5 +/- 1.1 minutes (p0.01).Differences in cardiopulmonary bypass cooling techniques may alter the rate at which jugular bulb saturations rise. We believe this represents an indirect measure of the efficiency of brain cooling and therefore of cerebral protection.

Children with visceral heterotaxy often present with total anomalous pulmonary venous drainage (TAPVD) associated with univentricular congenital heart disease. We reviewed our experience with the primary surgical management of this lesion under these circumstances. Over a recent 10-year span, 38 patients within the first 3 days of life were admitted to our institution and underwent primary palliation. Twenty-one of them had TAPVD, 18 to a systemic vein. Twelve (67%) of these 18 were seen with obstruction of the anomalous connection and underwent emergency operation. In 7 patients, repair of TAPVD was combined with a systemic-pulmonary artery shunt because of additional obstruction of the pulmonary blood supply, with two deaths. One patient had primary shunting and then repair of TAPVD. Four patients underwent repair of TAPVD alone. Two of them then showed signs of insufficient pulmonary blood flow, received a shunt in a second procedure, and subsequently died. Early mortality in the group with obstructed TAPVD was thus 4 (33%) of 12 patients. Statistical analysis of all 38 patients (univariate analysis, chi 2 testing) showed that neither the presence of TAPVD (p = 0.7) nor TAPVD repair alone (p = 0.8) or with shunting (p = 0.8) was a definite risk factor for early death. The performance of a shunt during the first operation, however, was associated with lower early mortality (p = 0.03). Total anomalous pulmonary venous drainage is a common finding in newborns with visceral heterotaxy. Its presence and its subsequent early repair (requiring cardiopulmonary bypass) do not increase the mortality risk. The need of a concomitant shunt in obstructed TAPVD can initially be underestimated.

The integrity of the blood-cerebrospinal fluid (CSF) barrier during cardiopulmonary bypass (CPB) with hypothermic circulatory arrest (HCA) has not been systematically studied, especially in children. We tested the hypothesis that the blood-CSF barrier is disrupted by CPB.The study randomized 25 piglets (mean weight, 11 kg) to five groups (5 per group): anesthesia alone (control); CPB at 37 degrees C with full-flow (FF); CPB at 25 degrees C with very low flow (LF); and HCA at 15 degrees C and 25 degrees C. pH-stat strategy was applied during CPB. An epidural catheter was inserted into the cisterna magna for collection of CSF. CSF and blood samples were collected at seven points: after induction of anesthesia (baseline), at 10, 50 and 115 minutes after start of CPB, just before the end of CPB, and at 30 and 120 minutes after CPB. Albumin levels in CSF and plasma were measured to assess blood-CSF barrier integrity and the albumin ratio (CSF/plasma) was calculated (Q(Alb)).In both HCA groups, the Q(Alb) was significantly higher than in the control and 37 degrees C FF groups (all p0.05), whereas Q(Alb) in the 37 degrees C group was not significantly different vs control.The blood-CSF barrier is impaired by CPB with 1 hour of 15 degrees C or 25 degrees C HCA. Further investigations are needed to understand the behavior of the blood-CSF barrier during CPB and its role in neuroprotection.

An 11.5-month-old child was found to have a widely patent ductus arteriosus 8 months after percutaneous Amplatzer device closure of the ductus. Angiography confirmed that the occlusion device had migrated to the descending thoracic aorta. The child underwent surgical removal of the device, which was firmly embedded in the aorta and could not be removed percutaneously.

In previous studies we have shown that delayed capillary reperfusion after low flow bypass predicts neurologic injury. In this acute study, we hypothesized that low flow reduces endothelial nitric oxide synthase (eNOS) expression, which may lead to more profound inflammatory response and delayed capillary perfusion.Twelve piglets (13.2 +/- 0.7 kg) had a cranial window placed over the parietal cerebral cortex for direct examination of the microcirculation using intravital fluorescence microscopy. Animals were cooled to 15 degrees C or 34 degrees C on cardiopulmonary bypass (pH stat, hematocrit 30%, pump flow 100 mL/kg/minute) followed by 2 hours of low flow (50 mL/kg/minute) or very low flow (10 mL/kg/minute). Rhodamine staining was used to observe adherent and rolling leukocytes in postcapillary venules. The eNOS protein expression was determined by Western immunoblotting.High temperature and low flow rate correlated with significantly reduced eNOS expression (p0.01). Univariate comparisons based on Student t tests indicated that eNOS protein levels were lower at 34 degrees C than at 15 degrees C (0.7 +/- 0.6 vs 1.7 +/- 0.5, p0.01) and at 10 mL/kg per minute compared with 50 mL/kg per minute (0.8 +/- 0.7 vs 1.6 +/- 0.5, p = 0.03). Moreover, two-way analysis of variance revealed that temperature (F = 21.6, p0.001) and flow rate (F = 13.8, p = 0.005) were independent multivariate predictors of eNOS expression. During low flow bypass, eNOS was inversely correlated with numbers of adherent (p = 0.002) and rolling (p = 0.006) leukocytes, following an exponential decay curve closely.eNOS expression is reduced after very low flow bypass, particularly at a higher bypass temperature. This is associated with delayed capillary reperfusion. Reduced eNOS is also associated with increased white cell activation which may lead to greater neurologic injury.

Background. Experimental data have suggested that early postoperative temperature management after cerebral ischemia may alter neurologic outcome. We explored whether minor deviations in early postoperative body temperature after infant heart surgery affects developmental outcome. Methods. In a study of infants undergoing repair of congenital heart disease, 95% of whom had a period of deep hypothermic circulatory arrest, postoperative temperature data were collected following cardiac surgery. Subjects were infants who had been enrolled in one of two prospective randomized single-center trials. Development was tested at age one year (the Bayley Scales of Infant Development) and at four years (Wechsler Preschool and Primary Scale of Intelligence, including Full Scale IQ, a Verbal IQ, and a Performance IQ). Results. Perioperative temperature data were reviewed in 329 patients, of whom 244 (74%) were evaluated at age one year and 156 (48%) were evaluated at four years. The temperature profile was recorded during the rewarming phase and for 36 hours postoperatively on the Intensive Care Unit. There were no significant associations between postoperative temperature and any of the neurodevelopmental tests at age one or four years. A further analysis assessing the percentage of time over specific temperature cutoff points of 37.5°C, 38°C, 38.5°C, and 39°C, revealed no significant effect. Conclusions. Neurodevelopmental outcome at one and four years after repair of complex congenital heart disease was not significantly affected by the early postoperative body temperature profile of the infant when a management strategy aiming for normothermia is employed.

Tetralogy of Fallot S,D,I is a recently discovered form of tetralogy with solitus atria (S) and d-loop ventricles (D), but with inverted normally related great arteries (I). Because of infundibuloarterial inversion, the right coronary artery must traverse the stenotic pulmonary outflow tract, increasing the risk of surgical trauma to the right coronary artery. Here we report a case of successful surgical repair of tetralogy of Fallot S,D,I without the use of an extracardiac conduit.

Background. Hemodilution continues to be widely used during cardiopulmonary bypass (CPB) for both adults and children. Previous studies with nonbypass models have suggested that an increase in cerebral blood flow (CBF) compensates for the reduced oxygen-carrying capacity; however, this increased CBF is achieved by an increase in cardiac output. We hypothesized that even with the fixed-flow perfusion of CPB, CBF would be increased during hemodilution. Methods. Two experiments were conducted and analyzed separately. In each experiment, 10 piglets were randomized to two different groups, one with a total blood prime yielding a high hematocrit (25% or 30%), and the other with a crystalloid prime resulting in a low hematocrit (10% or 15%). Animals were cooled with pH-stat strategy at full flow (100 or 150 mL · kg 1 · min 1 ) to a nasopharyngeal temperature of 15°C, a period of low flow (50 mL · kg 1 · min 1 ) preceding deep hypothermic circulatory arrest (45 or 60 minutes), and a period of rewarming at full flow. Cerebral blood flow was measured at the beginning of CPB, at the end of cooling, at the end of low flow, 5 minutes after the start of rewarming, and at the end of rewarming by injection of radioactive microspheres. Results. Mean arterial pressure was significantly greater with higher hematocrit at each time point (p< 0.05). Cerebral blood flow and the cerebral metabolic rate of oxygen decreased during cooling and further during low flow bypass but were significantly greater with lower hematocrit during mild hypothermia and at the end of rewarming (p< 0.05). Conclusions. Hemodilution is associated with decreased perfusion pressure, increased CBF and increased the cerebral metabolic rate of oxygen during hypothermic CPB.

Retrograde cerebral perfusion (RCP) is used in some centers during aortic arch surgery for brain protection during hypothermic circulatory arrest. It is still unclear however whether RCP provides adequate microcirculatory blood flow at a capillary level. We used intravital microscopy to directly visualize the cerebral capillary blood flow in a piglet model of RCP.Twelve pigs (weight 9.7 +/- 0.9 kg) were divided into two groups (n = 6 each): deep hypothermic circulatory arrest (DHCA) and RCP. After the creation of a window over the parietal cerebral cortex, pigs underwent 10 minutes of normothermic bypass and 40 minutes of cooling to 15 degrees C on cardiopulmonary bypass ([CPB] pH-stat, hemocrit 30%, pump flow 100 mL x kg(-1) x min(-1)). This was followed by 45 minutes of DHCA and rewarming on CPB to 37 degrees C. In the RCP group the brain was retrogradely perfused (pump flow 30 mL x kg(-1) x min(-1)) during DHCA through the superior vena cava after inferior vena cava occlusion. Plasma was labeled with fluorescein-isothiocyanate-dextran for assessing microvascular diameter and functional capillary density (FCD), defined as total length of erythrocyte-perfused capillaries per observation area. Cerebral tissue oxygenation was determined by nicotinamide adenine dinucleotide hydrogen (NADH) autofluorescence, which increases during tissue ischemia.During normothermic and hypothermic antegrade cerebral perfusion the FCD did not significantly change from base line (97% +/- 14% and 96% +/- 12%, respectively). During retrograde cerebral perfusion the FCD decreased highly significantly to 2% +/- 2% of base line values (p0.001). Thus there was no evidence of significant capillary blood flow during retrograde cerebral perfusion. The microvascular diameter of cerebral arterioles that were slowly perfused significantly decreased to 27% +/- 6% of base line levels during RCP. NADH fluorescence progressively and significantly increased during RCP, indicating poorer tissue oxygenation. At the end of retrograde cerebral perfusion there was macroscopic evidence of significant brain edema.RCP does not provide adequate cerebral capillary blood flow and does not prevent cerebral ischemia. Prolonged RCP induces brain edema. However, there might be a role for a short period of RCP to remove air and debris from the cerebral circulation after DHCA because retrograde flow could be detected in cerebral arterioles.

The optimal pH strategy and hematocrit during cardiopulmonary bypass with deep hypothermic circulatory arrest (DHCA) remain controversial. We studied the interaction of pH strategy and hematocrit and their combined impact on cerebral oxygenation and neurological outcome in a survival piglet model including monitoring by near-infrared spectroscopy (NIRS).Thirty-six piglets (9.2+/-1.1 kg) underwent DHCA under varying conditions with continuous monitoring by NIRS (pH-stat or alpha-stat strategy, hematocrit 20% or 30%, DHCA time 60, 80, or 100 minutes). Neurological recovery was evaluated daily. The brain was fixed in situ on postoperative day 4 and a histological score (HS) for neurological injury was assessed.Oxygenated hemoglobin (HbO2) and total hemoglobin signals detected by NIRS were significantly lower with alpha-stat strategy during cooling (p0.001), suggesting insufficient cerebral blood supply and oxygenation. HbO2 declined to a plateau (nadir) during DHCA. Time to nadir was significantly shorter in lower hematocrit groups (p0.01). Significantly delayed neurologic recovery was seen with alpha-stat strategy compared with pH-stat (p0.05). The alpha-stat group had a worse histological score compared with those assigned to pH-stat (p0.001). Neurologic impairment was estimated to be over 10 times more likely for animals randomized to alpha-stat compared with pH-stat strategy (odds ratio = 10.7, 95% confidence interval = 3.8 to 25.2).Combination of alpha-stat strategy and lower hematocrit exacerbates neurological injury after DHCA. The mechanism of injury is inadequate cerebral oxygenation during cooling and a longer plateau period of minimal O2 extraction during DHCA.

Low- and very low-birth weight infants are now candidates for reparative cardiac surgery. Outcomes after coarctation repair have not been characterized in this patient population.We performed a retrospective review of 18 consecutive neonates less than 2 kg who underwent repair of aortic coarctation between August 1990 and December 1999.Median weight was 1,330 g, and median gestational age was 31 weeks. A ventricular septal defect was present in 5 patients, and Shone's complex in 4. Sixteen patients had resection and end-to-end anastomosis, and 2 had resection and subclavian flap. Median clamp time was 15.5 minutes. One patient died during hospitalization. Two patients died late postoperatively (5-year estimated survival 80%). Mean follow-up was 28.5 months. Eight patients (44%) had a residual or recurrent coarctation, 5 underwent balloon dilation, and 3 underwent reoperation. Freedom from reintervention for recoarctation was 60% at 5 years. Shone's complex or a hypoplastic arch was an independent risk factor for decreased survival (p0.001). Very low birth weight was a multivariate predictor for increased risk of recoarctation (p = 0.01).Coarctation repair in less than 2-kg premature non-Shone's infants can be performed with a low mortality. The rate of recoarctation is higher in the very low-birth weight infants, but can be managed with low risk.

Background . From May 1996 to August 1998 a minimal access approach was used for 135 of 200 consecutive surgical atrial septal defects closures in children through young adults ranging in age from 6 months to 25 years (median 5 years). Methods . A 3.5- to 5-cm midline incision was centered over the xiphoid with division of the xiphoid alone (transxiphoid) or of the lower sternum (ministernotomy); both groups underwent bicaval venous cannulation through the incision. Cardioplegia and aortic cross-clamping were administered through the incision. Cephalad retraction of the sternum with a fixed-arm retractor aided exposure. Results . There have been no early or late deaths and no bleeding or wound complications. No procedure required conversion to a full sternotomy, and no cannulation attempt was abandoned for an alternate site. Cross-clamp and cardiopulmonary bypass times were equivalent to those in the full sternotomy group. The mean length of hospital stay in the ministernotomy group was 2.7 days. Conclusions . The closure of atrial septal defects can be performed through a transxiphoid or ministernotomy approach, conferring a satisfactory cosmetic result without compromising the safety or accuracy of the repair.

We report the case of a 41-year-old woman who presented with extensive papillary fibroelastomas of the heart after multiple previous surgical procedures for hypertrophic cardiomyopathy. This case is significant because of the locally aggressive nature of the cardiac papillary fibroelastoma.