Right Ventricular and Outflow Tract Functional Characteristics After Repair of Tetralogy of Fallot with Major Aortopulmonary Collaterals.

This study describes right ventricle (RV) characteristics and right ventricle to pulmonary artery (RV-PA) conduit function pre- and post-repair in patients with tetraology of Fallot with major aortopulmonary collaterals (TOF/MAPCAs). We reviewed patients who underwent single-stage, complete unifocalization, and repair of TOF/MAPCAs between 2006 and 2019 with available pre- and early postoperative echocardiograms. For a subset of patients, 6-12 month follow-up echocardiogram was available. RV and left ventricle (LV) characteristics and RV-PA conduit function were reviewed. Wilcoxon signed rank test and McNemar's test were used. 170 patients were reviewed, 46 had follow-up echocardiograms. Tricuspid valve annular plane systolic excursion (TAPSE) Z-scores were reduced from pre- (Z-score 0.01) to post-repair (Z-score -4.5, p < 0.001), improved but remained abnormal at follow-up (Z-score -4.0, p < 0.001). RV fractional area change (FAC) and LV ejection fraction were not significantly different before and after surgery. Conduit regurgitation was moderate or greater in 11% at discharge, increased to 65% at follow-up. RV-PA conduit failure (severe pulmonary stenosis or severe pulmonary regurgitation) was noted in 61, and 63% had dilated RV (diastolic RV area Z-score > 2) at follow-up. RV dilation correlated with the severe conduit regurgitation (p = 0.018). Longitudinal RV function was reduced after complete repair of TOF/MAPCAs, with decreased TAPSE and preserved FAC and LV ejection fraction. TAPSE improved but did not normalize at follow-up. Severe RV-PA conduit dysfunction was observed prior to discharge in 11% of patients and in 61% at follow-up. RV dilation was common at follow-up, especially in the presence of severe conduit regurgitation.

The development and efficacy of a paediatric cardiology fellowship online preparatory course.

BACKGROUND: The transition from residency to paediatric cardiology fellowship is challenging due to the new knowledge and technical skills required. Online learning can be an effective didactic modality that can be widely accessed by trainees. We sought to evaluate the effectiveness of a paediatric cardiology Fellowship Online Preparatory Course prior to the start of fellowship. METHODS: The Online Preparatory Course contained 18 online learning modules covering basic concepts in anatomy, auscultation, echocardiography, catheterisation, cardiovascular intensive care, electrophysiology, pulmonary hypertension, heart failure, and cardiac surgery. Each online learning module included an instructional video with pre-and post-video tests. Participants completed pre- and post-Online Preparatory Course knowledge-based exams and surveys. Pre- and post-Online Preparatory Course survey and knowledge-based examination results were compared via Wilcoxon sign and paired t-tests. RESULTS: 151 incoming paediatric cardiology fellows from programmes across the USA participated in the 3 months prior to starting fellowship training between 2017 and 2019. There was significant improvement between pre- and post-video test scores for all 18 online learning modules. There was also significant improvement between pre- and post-Online Preparatory Course exam scores (PRE 43.6 ± 11% versus POST 60.3 ± 10%, p < 0.001). Comparing pre- and post-Online Preparatory Course surveys, there was a statistically significant improvement in the participants' comfort level in 35 of 36 (97%) assessment areas. Nearly all participants (98%) agreed or strongly agreed that the Online Preparatory Course was a valuable learning experience and helped alleviate some anxieties (77% agreed or strongly agreed) related to starting fellowship. CONCLUSION: An Online Preparatory Course prior to starting fellowship can provide a foundation of knowledge, decrease anxiety, and serve as an effective educational springboard for paediatric cardiology fellows.

Proton magnetic resonance spectroscopy assessment of neonatal brain metabolism during cardiopulmonary bypass surgery.

Here, we report on the development and performance of a robust 3-T single-voxel proton magnetic resonance spectroscopy (1 H MRS) experimental protocol and data analysis pipeline for quantifying brain metabolism during cardiopulmonary bypass (CPB) surgery in a neonatal porcine model, with the overall goal of elucidating primary mechanisms of brain injury associated with these procedures. The specific aims were to assess which metabolic processes can be reliably interrogated by 1 H MRS on a 3-T clinical scanner and to provide an initial assessment of brain metabolism during deep hypothermia cardiac arrest (DHCA) surgery and recovery. Fourteen neonatal pigs underwent CPB surgery while placed in a 3-T MRI scanner for 18, 28, and 37°C DHCA studies under hyperglycemic, euglycemic, and hypoglycemic conditions. Total imaging times, including baseline measurements, circulatory arrest (CA), and recovery averaged 3 h/animal, during which 30-40 single-voxel 1 H MRS spectra (sLASER pulse sequence, TR/TE = 2000/30 ms, 64 or 128 averages) were acquired from a 2.2-cc right midbrain voxel. 1 H MRS at 3 T was able to reliably quantify (1) anaerobic metabolism via depletion of brain glucose and the associated build-up of lactate during CA, (2) phosphocreatine (PCr) to creatine (Cr) conversion during CA and subsequent recovery upon reperfusion, (3) a robust increase in the glutamine-to-glutamate (Gln/Glu) ratio during the post-CA recovery period, and (4) a broadening of the water peak during CA. In vivo 1 H MRS at 3 T can reliably quantify subtle metabolic brain changes previously deemed challenging to interrogate, including brain glucose concentrations even under hypoglycemic conditions, ATP usage via the conversion of PCr to Cr, and differential changes in Glu and Gln. Observed metabolic changes during CPB surgery of a neonatal porcine model provide new insights into possible mechanisms for prevention of neuronal injury.

Comprehensive diagnostic catheterization in children with major aortopulmonary collateral arteries: A review of catheterization technique and anatomic nomenclature.

Achieving an optimal surgical result in patients with major aortopulmonary collateral arteries (MAPCAs) requires a thorough preoperative evaluation of the anatomy and physiology of the pulmonary circulation. This review provides a detailed description of diagnostic catheterization in patients with MAPCAs, including a summary of catheterization techniques, an overview of commonly used terms, and a review of MAPCA and pulmonary artery angiographic anatomy.

Airway Characteristics of Patients With 22q11 Deletion Undergoing Pulmonary Artery Reconstruction Surgery: Retrospective Cohort Study.

OBJECTIVES: We have previously shown that patients with a chromosome 22q11 microdeletion are at risk for prolonged respiratory failure after pulmonary artery reconstruction surgery compared with those with normal genotype. We sought to describe preexisting airway abnormalities in this patient population and examine relationships between airway abnormalities and outcomes. DESIGN: Single-center retrospective chart review from Society of Thoracic Surgery and Pediatric Cardiac Critical Care Consortium databases and the electronic medical record. SETTING: Lucile Packard Children's Hospital at Stanford from September 2017 to February 2019. PATIENTS: All patients undergoing pulmonary artery reconstruction surgery were considered for inclusion. INTERVENTIONS: We identified 127 patients meeting study inclusion criteria. Thirty-nine patients met specific criteria and underwent screening preoperative bronchoscopy including microdirect laryngoscopy and lower airway examination. Postoperative bronchoscopy was performed at the discretion of the intensive care team. MEASUREMENTS AND MAIN RESULTS: Airway abnormalities were detected in 25/26 of children (96%) with a chromosome 22q11 deletion who underwent preoperative bronchoscopy. Upper and lower airway pathologies were found in 19/25 (73%) and 21/25 (81%) patients, respectively, and it was common for patients to have more than one abnormality. Presence of 22q11 deletion was associated with longer duration of mechanical ventilation (9.1 vs 4.3 d; p = 0.001), use of noninvasive positive pressure support (13 vs 6 d; p = 0.001), and longer hospital stays (30 vs 14 d; p = 0.002). These outcomes were worse when compared with patients with known airway abnormalities who did not have 22q11 deletion. CONCLUSIONS: Preexisting upper and lower airway pathologies are common in patients with a chromosome 22q11 deletion who undergo pulmonary artery reconstruction surgery. Despite similar postoperative hemodynamics and outcomes as their counterparts without 22q11 deletion, 22q11 deletion is associated with more postoperative respiratory complications not entirely explained by preexisting airway abnormalities.

The number of postoperative surgical or diagnostic procedures following congenital heart surgery correlates with both mortality and hospital length of stay.

BACKGROUND: Outcomes for congenital heart disease have dramatically improved over the past several decades. However, there are patients who encounter intraoperative or postoperative complications and ultimately do not survive. It was our hypothesis that the number of postoperative procedures (including surgical and unplanned diagnostic procedures) would correlate with hospital length of stay and operative mortality. METHODS: This was a retrospective review of 938 consecutive patients undergoing congenital heart surgery at a single institution over a 2-year timeframe. The number of postoperative surgical and unplanned diagnostic procedures were counted and the impact on hospital length of stay and mortality was assessed. RESULTS: 581 of the 938 (62%) patients had zero postoperative diagnostic or surgical procedures. These patients had a median length of stay of 6 days with a single operative mortality (0.2%). 357 of the 938 (38%) patients had one or more postoperative diagnostic or surgical procedures. These patients had a total of 1586 postoperative procedures. There was a significant correlation between the number of postoperative procedures and both hospital length of stay and mortality (p < .001). Patients who required 10 or more postoperative procedures had a median hospital length of stay of 89 days and had a 50% mortality. There were no survivors in patients who had 15 or more postoperative procedures. CONCLUSIONS: The data demonstrate that the number of postoperative procedures was highly correlated with both hospital length of stay and mortality.

Overview of Cardiopulmonary Bypass Techniques and the Incidence of Postoperative Complications in Pediatric Patients Undergoing Complex Pulmonary Artery Reconstruction.

Cardiopulmonary bypass (CPB) is routinely used for performing congenital heart operations. While most congenital heart operations can be performed with bypass times under 2 hours, complex pulmonary artery reconstructions require longer periods of CPB to facilitate the surgical repair. This article is intended to summarize the surgical and perfusion techniques utilized in patients undergoing complex pulmonary artery reconstructions at our institution. The initial portion of this manuscript provides an in-depth description of the surgical techniques employed for pulmonary artery reconstructions. This information is important in order to understand why prolonged CPB is a necessary requirement. The manuscript then provides a detailed description of the perfusion techniques and the modifications to the CPB circuit. Finally, the manuscript provides a summary of data from a clinical study evaluating the application of these techniques in 100 consecutive children undergoing complex pulmonary artery reconstruction. The data from this study demonstrated that there was a poor correlation between duration of CPB and both the number of postoperative complications and hospital length of stay. Major adverse cardiac events occurred in 11 (11%) patients with one hospital mortality. These results suggest that prolonged CPB does not predispose to adverse outcomes in this select population of patients.

Outcomes in Patients with Alagille Syndrome and Complex Pulmonary Artery Disease.

OBJECTIVE: To assess outcomes in a large cohort of patients with Alagille syndrome (ALGS) who underwent pulmonary artery reconstruction surgery for complex pulmonary artery disease. STUDY DESIGN: Patients with ALGS who underwent pulmonary artery reconstruction surgery at Lucile Packard Children's Hospital Stanford were reviewed. Patients were examined as an overall cohort and based on the primary cardiovascular diagnosis: severe isolated branch pulmonary artery stenosis, tetralogy of Fallot (TOF) without major aortopulmonary collateral arteries (MAPCAs), or TOF with MAPCAs. RESULTS: Fifty-one patients with ALGS underwent pulmonary artery surgery at our center, including 22 with severe branch pulmonary artery stenosis, 9 with TOF without MAPCAs, and 20 with TOF and MAPCAs. Forty-one patients (80%) achieved a complete repair. Five of the patients with TOF with MAPCAs (25%) underwent complete repair at the first surgery, compared with 8 (89%) with TOF without MAPCAs and 19 (86%) with isolated branch pulmonary artery stenosis. At a median follow-up of 1.7 years after the first surgery, 39 patients (76%) were alive, 36 with a complete repair and a median pulmonary artery:aortic systolic pressure of 0.38. Nine patients (18%), including 8 with isolated branch pulmonary artery stenosis, underwent liver transplantation. CONCLUSIONS: Most patients with ALGS and complex pulmonary artery disease can undergo complete repair with low postoperative right ventricular pressure. Patients with TOF/MAPCAs had the worst outcomes, with higher mortality and more frequent pulmonary artery interventions compared with patients with TOF without MAPCAs or isolated branch pulmonary artery stenosis. Complex pulmonary artery disease is not a contraindication to liver transplantation in patients with ALGS.

Pulmonary arteries of Williams syndrome patients exhibit altered serotonin metabolism genes and degenerated medial layer architecture.

BACKGROUND: Williams-Beuren syndrome (WS) is characterized by cardiovascular abnormalities associated with a multigene deletion on 7q11.23, in particular elastin (ELN). Peripheral pulmonary artery stenosis (PPAS) frequently affects pediatric patients with WS. Molecular investigation of WS pulmonary arterial (PA) tissue is limited by tissue scarcity. METHODS: We compared transcriptomes, tissue architecture, and localized changes in protein expression in PA tissue from patients with WS (n = 8) and donors (n = 5). RESULTS: Over 100 genes were differentially expressed at the ≥4-fold level, including genes related to the serotonin signaling pathway: >60-fold downregulation of serotonin transporter SLC6A4 and >3-fold upregulation of serotonin receptor HTR2A. Histologic examination revealed abnormal elastin distribution and smooth muscle cell morphology in WS PA, with markedly shorter, disorganized elastin fibers, and expanded proteoglycan-rich extracellular matrix between muscle layers. CONCLUSIONS: There were significant abnormalities in the PA expression of genes regulating serotonin signaling, metabolism, and receptors in WS. Those changes were associated with distinct changes in the arterial structure and may play a role in the stenosis-promoting effects of elevated shear stress at PA bifurcations in WS. IMPACT: Serotonin pathway signaling is significantly altered in the pulmonary arteries of patients with Williams syndrome and severe peripheral arterial stenosis. The present study compares the histological and biochemical characteristics of pulmonary arteries from patients with Williams syndrome to those of controls, something that has not, to our knowledge, been done previously. It demonstrates marked abnormalities in the pulmonary arteries of patients with Williams syndrome, especially significant pathologic alterations in the signaling of the serotonin pathway. The findings of this study provide direction for the development of potential therapies to treat pulmonary artery stenosis in patients with Williams syndrome.

Longitudinal Assessment of Right Ventricular Function in Hypoplastic Left Heart Syndrome.

Overall survival of patients with hypoplastic left heart syndrome (HLHS) has shown continued improvement. Right ventricular (RV) dysfunction, in the long term, adversely affects prognosis in these patients. This study examines changes in echocardiographic markers of RV function in a longitudinal cohort. We retrospectively reviewed patients with HLHS managed at our institution from 7/1994 to 1/2016. Follow-up included surgical and clinical data, and echocardiographic measures. Measures of RV function preceding and following all three stages of single ventricular palliation were collected. Freedom from transplant-free survival was assessed by Kaplan-Meier analysis. Multivariable associations with time to death or transplant were explored using the Cox proportional hazards model. A total of 120 patients with HLHS were identified. Norwood operation was performed in all patients. The probability of survival for the cohort was 71 ± 4.4%, 69 ± 4.5% and 66 ± 4.7% at 1, 2 and 5 years respectively after stage I Norwood operation. RV fractional area change (FAC), compared to post-Norwood was decreased at all subsequent stages with the greatest change noted post-superior cavo-pulmonary shunt from 40.7 ± 9.3% to 31.1 ± 8.3% (p < 0.001). Similarly, tricuspid valve annular systolic excursion (TAPSE) Z-score declined from -2.9 ± 1.3 to -9.7 ± 1.3 (p < 0.001) with a decrement at every stage of evaluation. In comparison to patients with post-Norwood RV FAC >35% and TAPSE Z-score > -5, patients with RV FAC ≤ 35% and TAPSE Z-score ≤ -5 had a significantly lower transplant-free survival (p < 0.0001). In patients with HLHS undergoing staged palliation, decrement in RV function manifests longitudinally. Post-Norwood RV FAC and TAPSE Z-score appear to be early markers of poor outcome in this population.

Fibrinogen Concentrate as an Alternative to Cryoprecipitate in a Postcardiopulmonary Transfusion Algorithm in Infants Undergoing Cardiac Surgery: A Prospective Randomized Controlled Trial.

BACKGROUND: Infants undergoing cardiac surgery are at risk for bleeding and massive transfusion due to an immature coagulation system, complex surgeries, and cardiopulmonary bypass (CPB) effects. Hemodilution from CPB promotes an acquired hypofibrinogenemia that results in impaired fibrin formation, inadequate clot formation, and increased bleeding. In North America, the current standard of care to supplement fibrinogen is cryoprecipitate. An alternative option is the off-label use of fibrinogen concentrate (FC; RiaSTAP; CSL Behring, Marburg, Germany), a purified fibrinogen. Because perioperative allogenic transfusions are associated with increased morbidity and mortality, we sought to determine whether FC would be an acceptable alternative to cryoprecipitate in a post-CPB transfusion algorithm in infants undergoing open-heart surgery. METHODS: We randomized 60 infants (<12 months) undergoing nonemergent cardiac surgery with CPB at 2 tertiary care children's hospitals to receive either cryoprecipitate or FC in a post-CPB transfusion algorithm. Infants underwent a stratified randomization based on institution and surgical complexity. The primary outcome was the difference in number of intraoperative allogenic blood product transfusions. Secondary outcomes included 24-hour chest tube output (CTO), mechanical ventilation time, adverse events (AEs), intensive care unit (ICU) length of stay (LOS), hospital LOS, postoperative thrombosis, and death within 30 days of surgery. The primary analysis followed the intent-to-treat (ITT) principle and was performed using linear regression adjusted for institution and complexity of surgery. A per-protocol (PP) analysis was also performed. RESULTS: Between June 2016 and January 2018, we enrolled 60 patients with complete data available for 25 patients who received cryoprecipitate and 29 patients who received FC. Patients in the cryoprecipitate group (median age: 4 months [2-6 months]) received 5.5 (4.0-7.0) allogeneic blood units in the ITT analysis and 6.0 units (5.0-7.0 units) in the PP analysis. Patients in the FC group (median age: 4 months [2-5]) received 4 units (3.0-5.0 units) in the ITT analysis and 4.0 units (3.0-5.0 units) in the PP analysis. In the adjusted ITT analysis, the FC group received 1.79 units (95% confidence interval [CI], 0.64-2.93; P = .003) less than the cryoprecipitate group. In the adjusted PP analysis, the FC group received 2.67 units (95% CI, 1.75-3.59; P < .001) less than the cryoprecipitate group. There were no significant differences in secondary outcomes or AEs. CONCLUSIONS: Our findings suggest that FC may be considered as an alternative to cryoprecipitate for the treatment of hypofibrinogenemia in infants with bleeding after CPB. Although we found no significant differences between secondary outcomes or AEs, further studies are needed to assess safety.

Corrected Transposition: Anatomic Repair Using the Hemi-Mustard Atrial Baffle and Bidirectional Superior Cavopulmonary Connection.

Anatomic repair for congenitally corrected transposition requires thoughtful surgical planning at both initial (neonatal or late) presentation, and during definitive repair. An algorithmic approach to the overall management of this lesion, with its many associated intracardiac anomalies, is presented. Modified atrial switch with bidirectional superior cavopulmonary connection is commonly utilized and demonstrates favorable results through a 20-year experience. Herein, technical considerations learned during the implementation of this strategy are described and emphasize the concept, in selected cases, of native pulmonary root preservation by translocation as an adjunct that is uniquely suited by adopting this approach.

Deletion of 22q11 chromosome is associated with postoperative morbidity after unifocalisation surgery.

BACKGROUND: A 22q11 chromosome deletion is common in patients with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals. We sought to determine whether 22q11 chromosome deletion is associated with increased postoperative morbidity after unifocalisation surgery. METHODS: We included all patients with this diagnosis undergoing primary or revision unifocalisation ± ventricular septal defect closure at our institution from 2008 to 2016, and we excluded patients with unknown 22q11 status. Demographic and surgical data were collected. We compared outcomes between those with 22q11 chromosome deletion and those without using non-parametric analysis. RESULTS: We included 180 patients, 41% of whom were documented to have a chromosome 22q11 deletion. Complete unifocalisation was performed in all patients, and intracardiac repair was performed with similar frequency regardless of 22q11 chromosome status. Duration of mechanical ventilation was longer in 22q11 deletion patients. This difference remained significant after adjustment for delayed sternal closure and/or intracardiac repair. Duration of ICU stay was longer in patients with 22q11 deletion, although no longer significant when adjusted for delayed sternal closure and intracardiac repair. Finally, length of hospital stay was longer in 22q11-deleted patients, but this difference was not significant on unadjusted or adjusted analysis. CONCLUSION: Children with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals and 22q11 deletion are at risk for greater prolonged mechanical ventilation after unifocalisation surgery. Careful attention should be given to the co-morbidities of this population in the perioperative period to mitigate risks that may complicate the postoperative course.

Assessment of airway abnormalities in patients with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals.

BACKGROUND: Children with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals (TOF/MAPCAs) are at risk for post-operative respiratory complications after undergoing unifocalisation surgery. Thus, we assessed and further defined the incidence of airway abnormalities in our series of over 500 children with TOF/MAPCAs as determined by direct laryngoscopy, chest computed tomography (CT), and/or bronchoscopy. METHODS: The medical records of all patients with TOF/MAPCAs who underwent unifocalisation or pulmonary artery reconstruction surgery from March, 2002 to June, 2018 were reviewed. Anaesthesia records, peri-operative bronchoscopy, and/or chest CT reports were reviewed to assess for diagnoses of abnormal or difficult airway. Associations between chromosomal anomalies and airway abnormalities - difficult anaesthetic airway, bronchoscopy, and/or CT findings - were defined. RESULTS: Of the 564 patients with TOF/MAPCAs who underwent unifocalisation or pulmonary artery reconstruction surgery at our institution, 211 (37%) had a documented chromosome 22q11 microdeletion and 28 (5%) had a difficult airway/intubation reported at the time of surgery. Chest CT and/or peri-operative bronchoscopy were performed in 234 (41%) of these patients. Abnormalities related to malacia or compression were common. In total 35 patients had both CT and bronchoscopy within 3 months of each other, with concordant findings in 32 (91%) and partially concordant findings in the other 3. CONCLUSION: This is the largest series of detailed airway findings (direct laryngoscopy, CT, and bronchoscopy) in TOF/MAPCAS patients. Although these findings are specific to an at-risk population for airway abnormalities, they support the utility of CT and /or bronchoscopy in detecting airway abnormalities in patients with TOF/MAPCAs.

Perfusion Methods and Modifications to the Cardiopulmonary Bypass Circuit for Midline Unifocalization Procedures.

Pulmonary atresia with ventricular septal defect and major aortopulmonary collateral arteries (PA/VSD/MAPCAs) is a rare form of congenital heart disease. The midline unifocalization procedure has been developed for the treatment of PA/VSD/MAPCAs. These are complex and very lengthy procedures that require an entirely different method of perfusion. The purpose of this study was to review our perfusion modifications to support these unifocalization procedures. Sixty-four unifocalization procedures have been performed at our institution during the past 3 years. The median age was 4.1 months (range 1 month-3.5 years) and the median weight at surgery was 4.5 kg (range 3.5-19 kg). The median duration of cardiopulmonary bypass was 352 minutes (range 128-629 minutes), and the median duration of cross-clamp was 24 minutes (range 14-72 minutes). The conduct of surgery included cooling to a rectal perfusion temperature of 25° and a flow rate of 100 mL/kg/min. A pH-stat strategy and del Nido cardioplegia were used. Modifications to the cardiopulmonary bypass circuit include upsizing the oxygenator, reservoir, cannulae, vent catheter, and tubing. All circuits were modified to include the capability of performing an intraoperative flow study. This study is used to determine whether the VSD can be closed during surgery. A collateral flow study circuit is also set up for first-time operations to measure the residual collateral flow after all of the MAPCAs have been harvested. Patients who require midline unifocalization will invariably require very lengthy periods of support on cardiopulmonary bypass. We have adapted our perfusion circuitry to prepare for the demands on the bypass circuit to meet the requirements of this patient population. Our institution has developed a systematic approach for the conduct of perfusion to best serve our patients presenting with PA/VSD/MAPCAs.

Comprehensive Management of Major Aortopulmonary Collaterals in the Repair of Tetralogy of Fallot.

The heterogenous anatomy of Tetralogy of Fallot with major aortopulmonary collateral arteries has engendered a similar degree of diversity in its management and, ultimately, outcome. We summarize our comprehensive treatment paradigm for this lesion evolved over 15 years of experience through 458 patients and the results obtained. An updated analysis of 307 patients treated primarily at our institution is included. A review of recent literature, comparison of management strategies, and discussion of ongoing controversies are provided.

Postoperative feeding problems in patients with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals undergoing unifocalisation surgery.

BACKGROUND: Patients with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals are at risk for prolonged hospitalisation after unifocalisation. Feeding problems after congenital heart surgery are associated with longer hospital stay. We sought to determine the impact of baseline, intra-operative, and postoperative factors on the need for feeding tube use at the time of discharge. METHODS: We included patients with the aforementioned diagnosis undergoing unifocalisation from ages 3 months to 4 years from 2010 to 2016. We excluded patients with a pre-existing feeding tube. Patients discharged with an enteric tube were included in the feeding tube group. We compared the feeding tube group with the non-feeding-tube group by univariable and multi-variable logistic regression. RESULTS: Of the 56 patients studied, 41% used tube feeding. Median age and weight z-score were similar in the two groups. A chromosome 22q11 deletion was associated with the need for a feeding tube (22q11 deletion in 39% versus 15%, p=0.05). Median cardiopulmonary bypass time in the feeding tube group was longer (335 versus 244 minutes, p=0.04). Prolonged duration of mechanical ventilation was associated with feeding tube use (48 versus 3%, p=0.001). On multi-variable analysis, prolonged mechanical ventilation was associated with feeding tube use (odds ratio 10.2, 95% confidence intervals 1.6; 63.8). CONCLUSION: Among patients with tetralogy of Fallot, pulmonary atresia, and major aortopulmonary collaterals who were feeding by mouth before surgery, prolonged mechanical ventilation after unifocalisation surgery was associated with feeding tube use at discharge. Anticipation of feeding problems in this population and earlier feeding tube placement may reduce hospital length of stay.

Practice Patterns in Postoperative Echocardiographic Surveillance after Congenital Heart Surgery in Children: A Single Center Experience.

OBJECTIVES: To review current institutional practice and describe factors contributing to variation in inpatient postoperative imaging surveillance after congenital heart surgery. STUDY DESIGN: We reviewed records of all children who underwent congenital heart surgery from June to December 2014. Number and primary indications for postoperative transthoracic echocardiograms (TTEs), providers involved, cardiovascular intensive care unit (CVICU) and total hospital length of stay, and Risk-Adjustment for Congenital Heart Surgery-1 scores were recorded. RESULTS: A total of 253 children (age at surgery: 8 months [2 days-19 years]) received 556 postoperative TTEs (median 1 TTE/patient [1-14]), and 23% had ≥3 TTEs. Fifteen of 556 TTEs (2.7%) revealed a new abnormal finding. The majority of TTEs (59%) were performed in the CVICU (1.5 ± 1.1 TTEs/week/patient), with evaluation of function as the most common indication (44%). Attending physician practice >10 years was not associated with fewer TTEs (P = .12). Patients with ≥3 TTEs had higher Risk-Adjustment for Congenital Heart Surgery-1 scores (P = .001), longer CVICU lengths of stay (22 vs 3 days; P < .0001), longer overall hospitalizations (28 vs 7 days; P < .0001), and a higher incidence of mechanical circulatory support (10% vs 0%; P < .0001) than those with <3 TTEs. Eight patients with ≥3 TTEs did not survive, compared with 3 with <3 TTEs (P = .0004). CONCLUSIONS: There was wide intra-institutional variation in echocardiographic use among similar complexity surgeries. Frequency of postoperative echocardiographic surveillance was associated with degree of surgical complexity and severity of postoperative clinical condition. Few studies revealed new abnormal findings. These results may help establish evidence-based guidelines for inpatient echocardiographic surveillance after congenital heart surgery.

Acute Kidney Injury in Patients Undergoing the Extracardiac Fontan Operation With and Without the Use of Cardiopulmonary Bypass.

OBJECTIVES: To describe the prevalence and risk factors for acute kidney injury in patients undergoing the extracardiac Fontan operation with and without cardiopulmonary bypass, and to determine whether acute kidney injury is associated with duration of mechanical ventilation, cardiovascular ICU and hospital postoperative length of stay, and early mortality. DESIGN: Single-center retrospective cohort study. SETTING: Pediatric cardiovascular ICU, university-affiliated children's hospital. PATIENTS: Patients with a preoperative creatinine before undergoing first-time extracardiac Fontan between January 1, 2004, and April 30, 2012. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Acute kidney injury occurred in 55 of 138 patients (39.9%), including 41 (29.7%) with stage 1, six (4.4%) with stage 2, and eight (5.8%) with stage 3 acute kidney injury. Cardiopulmonary bypass was strongly associated with a higher risk of any acute kidney injury (adjusted odds ratio, 4.8 [95% CI, 1.4-16.0]; p = 0.01) but not stage 2/3 acute kidney injury. Lower renal perfusion pressure on the day of surgery (postoperative day, 0) was associated with a higher risk of stage 2/3 acute kidney injury (adjusted odds ratio, 1.2 [95% CI, 1.0-1.5]; p = 0.03). Higher vasoactive-inotropic score on postoperative day 0 was associated with a higher risk for stage 2/3 acute kidney injury (adjusted odds ratio, 1.9 [95% CI, 1.0-3.4]; p = 0.04). Stage 2/3 acute kidney injury was associated with longer cardiovascular ICU length of stay (mean, 7.3 greater d [95% CI, 3.4-11.3]; p < 0.001) and hospital postoperative length of stay (mean, 6.4 greater d [95% CI, 0.06-12.5]; p = 0.04). CONCLUSIONS: Postoperative acute kidney injury in patients undergoing the extracardiac Fontan operation is common and is associated with lower postoperative renal perfusion pressure and higher vasoactive-inotropic score. Cardiopulmonary bypass was strongly associated with any acute kidney injury, although not stage 2/3 acute kidney injury. Stage 2/3 acute kidney injury is a compelling risk factor for longer cardiovascular ICU and hospital postoperative length of stay. Increased attention to and management of renal perfusion pressure may reduce postoperative acute kidney injury and improve outcomes.

Right Ventricular Outflow Tract Obstruction: Pulmonary Atresia With Intact Ventricular Septum, Pulmonary Stenosis, and Ebstein's Malformation.

OBJECTIVES: The objectives of this review are to discuss the anatomy, pathophysiology, clinical course, and current treatment strategies for pulmonary atresia with intact ventricular septum, pulmonary stenosis, and Ebstein's anomaly. DATA SOURCE: MEDLINE and PubMed. CONCLUSIONS: Considerable advances have been made in management strategies for these complex congenital heart lesions, which have led to improved outcomes.