Development of a novel 3D perfusable vascular graft model to elucidate the mechanisms for congenital heart disorders.

Pediatric heart transplantation is hampered by a chronic shortage of donor organs. This problem is further confounded by graft rejection. Identification of earlier indicators of pediatric graft rejection and development of subsequent strategies to counteract these effects will increase the longevity of transplanted pediatric hearts. Heart transplant reject is due to a complex series of events, resulting in CAV, which is thought to be mediated through a host immune response. However, the earlier events leading to CAV are not very well known. We hypothesize that early events related to ischemia reperfusion injury during pediatric heart transplantation are responsible for CAV and subsequent graft rejection. Identification of the molecular markers of ischemia reperfusion injury and development of subsequent therapies to block these pathways can potentially lead to a therapeutic strategy to reduce CAV and increase the longevity of the transplanted heart. To accomplish this goal, we have developed a perfusable vascular graft model populated with endothelial cells and demonstrated the feasibility of this model to understand the early events of ischemia reperfusion injury.

Assessment of B-Natriuretic Peptide Levels After Stage 1 Palliation in Hypoplastic Left Heart Syndrome Patients.

We describe the perioperative BNP trends in patients with HLHS from S1P until interstage discharge to home, death, or S2P. This prospective cohort study includes all newborns with hypoplastic left heart syndrome (HLHS) who underwent Norwood procedures (S1P) at Texas Children's Hospital from April 2018 through April 2019. Our study included 19 newborns with HLHS. There was no interstage mortality; 47% were discharged home prior to the S2P procedure. Nine patients (50%) had higher BNP levels immediately after arrival to the cardiac intensive care unit (ICU) after S1P compared to preoperative levels. BNP levels were higher in those with a shorter duration of mechanical intubation (P = 0.02) and those with moderately depressed right ventricular systolic function in the immediate postoperative period (P = 0.02). RVPAs patients had higher BNP levels (median 3357 pg/mL) than mBTTs (median 2862 pg/mL), that was not statistically significant (P = 0.4). Despite higher BNP levels in RVPAs in the early postoperative period, these subjects had shorter mechanical ventilation, ICU, and hospital length of stay duration. BNP trends for HLHS patients vary in the postoperative period after S1P. RVPAs had higher BNP levels than mBTTs in the early postoperative period after S1P; however, this was not associated with worse outcomes.

Atrial tachyarrhythmias after lung transplantation in children: A common occurrence.

BACKGROUND: Atrial arrhythmia's (AA) following lung transplant in adults are a well-described clinical finding. In pediatrics, however, there are limited data with some reports suggesting that arrhythmias are rare. METHODS: We performed a single-center retrospective review of lung transplant recipients from January 2013 to June 2020. A detailed evaluation of clinical characteristics, presence of arrhythmias, and outcomes was completed. Arrhythmias were documented based on inpatient telemetry or remote Holter monitoring. Analyses assessing risk factors for arrhythmias and associations with clinical outcomes were performed. RESULTS: Ninety-one lung transplants were performed in 90 patients. Post-operative AA occurred following 19% transplants. Ectopic atrial tachycardia was seen in 14%, atrial flutter in 2%, and a combination in 2%. The majority of these arrhythmias occurred within the first 45 days post-operatively. Antiarrhythmic treatment was required in 59%, but none required ablation or electrical cardioversion. In patients followed for a year or more, 88% had resolution of their arrhythmia. Arrhythmias were not associated with mortality. In further analysis, however, the presence of arrhythmia was associated with an increased length of ICU stay (median of 12 days (IQR 6, 23) versus 5 days (IQR 4, 9); p = .019) and overall length of hospital stay (median of 26 days (IQR 19, 36) versus 17 days (IQR 19, 36); p = .043). CONCLUSIONS: Atrial tachyarrhythmias after lung transplantation are common in the pediatric population and usually occur early. Although they frequently require medical therapy and are associated with longer stays, there is no associated increased mortality. In addition, the arrhythmias typically self-resolve.

Anterior Chest Wall Reconstruction After Separation of Thoraco-Omphalopagus Conjoined Twins With Cadaveric Rib Grafts and Omental Flap.

BACKGROUND: Anterior chest wall defects have a wide range of etiologies in the pediatric population, ranging from infection, tumor, and trauma to congenital diseases. The reconstructive goals include restoring skeletal stability, obliterating dead space, preserving cardiopulmonary mechanics, and protecting vital underlying mediastinal organs. Although various reconstructive methods have been described in the literature, selecting the optimal method is challenging for the growing pediatric skeleton. Here, we report a case of previously thoraco-omphalopagus twins who underwent successful separation and reconstruction and presented for definitive anterior chest wall reconstruction. METHODS: A pair of previously thoraco-omphalopagus conjoined twins underwent definitive anterior chest wall defect reconstruction using cadaveric ribs and omental flap. Twin A received 2 cadaveric ribs, whereas twin B had a much larger sternal defect that required 3 cadaveric ribs combined with an omental flap for soft tissue chest coverage. Both twins were followed up for 8 months. RESULTS: Twin A's postoperative course was uneventful, and she was discharged on postoperative day 6. Twin B's course was complicated, and she was discharged on supported ventilation on postoperative day 10. At 8 months postoperatively, both twins healed well, and chest radiographs confirmed the stability of the chest reconstructions. The rib grafts in the twin with a tracheostomy were not mobile, and the patient had a solid sternum with adequate pulmonary expansion. The construct initially did not facilitate pulmonary functioning, but after a healing process, it eventually allowed for the twin with the tracheostomy who required pulmonary assistance to no longer need this device. CONCLUSIONS: Cryopreserved cadaveric ribs and omental flaps offer safe and reliable reconstructive methods to successfully reconstruct congenital anterior chest wall skeletal defects in the growing pediatric population. The involvement of multidisciplinary team care is key to optimizing the outcomes.

Intramural course of an anomalous left coronary artery is not always associated with a slit-like ostium.

Anomalous aortic origin of the left coronary artery from an incorrect aortic sinus has been reported as the second most common causes of sudden cardiac arrest in young athletes. Intramural course of the proximal left coronary artery is considered a high-risk morphology. It is associated with a slit-like ostium and elliptical shape of the proximal artery. In this case, all pre-operative cardiac images demonstrated a round ostium and round luminal shape of the left coronary artery, which suggested no evidence of intramural course. On intraoperative inspection, although the ostium and proximal left coronary artery appeared round, the patient had a long intramural course of the left coronary artery which our surgeons performed a successful unroofing procedure. The post-operative images showed a patent new ostium from the correct aortic sinus. These findings are very unusual and proved that we should not exclude intramural course even in the absence of a slit-like ostium and elliptical shape of the proximal left coronary artery.

Evolution of surgical repair of intraseptal anomalous left coronary artery with myocardial ischaemia.

BACKGROUND: Anomalous aortic origin of the left coronary artery with intraseptal course is a rare coronary anomaly associated with an increased risk of myocardial ischaemia. The role and techniques for surgical intervention are evolving, with numerous novel surgical techniques for this challenging anatomy reported in the last 5 years. We report our single-centre experience with surgical repair of intraseptal anomalous left coronary artery in the paediatric population, including clinical presentation, evaluation, and short- to mid-term outcomes. METHODS: All patients with coronary anomalies presenting to our institution undergo standardised clinical evaluation. Five patients aged 4 to 17 years underwent surgical intervention for intraseptal anomalous aortic origin of the left coronary artery between 2012 and 2022. Surgical techniques included coronary artery bypass grafting (n = 1), direct reimplantation with limited supra-arterial myotomy via right ventriculotomy (n = 1), and transconal supra-arterial myotomy with right ventricular outflow tract patch reconstruction (n = 3). RESULTS: All patients had evidence of haemodynamically significant coronary compression, and three had evidence of inducible myocardial ischaemia pre-operatively. There were no deaths or major complications. Median follow-up was 6.1 months (range 3.1-33.4 months). Patients who underwent supra-arterial myotomy (with or without reimplantation) had improved coronary flow and perfusion based on stress imaging and catheterisation data. CONCLUSIONS: Surgical approaches to intraseptal anomalous left coronary artery with evidence of myocardial ischaemia continue to evolve, with new techniques demonstrating promising improvement in coronary perfusion. Further studies are warranted to determine long-term outcomes and refine indications for repair.

Left heart hypoplasia in the fetus: Echocardiographic predictors of outcome.

INTRODUCTION: Fetal left heart hypoplasia (LHH) with an apex-forming left ventricle may require neonatal intervention but it is difficult to predict. METHODS: We performed a retrospective study of fetuses with LHH defined as normal segmental anatomy, apex-/near-apex forming left ventricle, and ≥1 left-sided z-score ≤ -2 between 1997 and 2014. Fetuses with mitral or aortic atresia, critical aortic stenosis, extracardiac anomalies, or fetal intervention were excluded. Classification and regression tree analyses (CART) were performed to construct algorithms to predict postnatal circulation: no surgery versus biventricular surgery versus single ventricle (SV) palliation. RESULTS: Among 138 included fetuses, 52 (37%) underwent neonatal surgery, with 10 (7%) undergoing SV palliation. The strongest single outcome discriminator was exclusively left-to-right flow foramen ovale (FO) flow ≥32 weeks gestational age (GA) (seen in 0% with no surgery, 22% with biventricular surgery, 88% with SV palliation). On CART analysis >32 weeks GA, fetuses with right-to-left FO flow and aortopulmonary ratio >0.76 had 0% probability of neonatal surgery, while those with left-to-right FO flow and mitral valve z-score < -3.6 had a 70% probability of SV palliation. CONCLUSION: SV palliation is an uncommon outcome of fetal LHH. Fetal FO flow and other echocardiographic measures can help determine risk and type of postnatal intervention.

Opioid Weaning Protocol Using Morphine Compared With Nonprotocolized Methadone Associated With Decreased Dose and Duration of Opioid After Norwood Procedure.

OBJECTIVES: Opioids are used to manage pain, comfort, maintain devices, and decrease oxygen consumption around Norwood palliation (NP), but in high dose and prolonged exposure, they increase risk of tolerance and iatrogenic withdrawal syndrome (IAWS). Variability in practice for IAWS prevention potentially increases opioid dose and duration. We hypothesize that protocolized weaning with morphine (MOR) versus nonprotocolized methadone (MTD) is associated with reduction in opioid exposure. DESIGN: A before-versus-after study of outcomes of patients weaned with protocolized MOR versus nonprotocolized MTD including subset analysis for those patients with complications postoperatively. Primary endpoints include daily, wean phase, and total morphine milligram equivalent (MMEq) dose, duration, and, secondarily, length of stay (LOS). SETTING: Quaternary-care pediatric cardiac ICU. PATIENTS: Neonates undergoing single-ventricle palliation. INTERVENTIONS: Introduction of IAWS prevention protocol. MEASUREMENTS AND MAIN RESULTS: Analysis included 54 patients who underwent the NP in 2017-2018 including the subset analysis of 34 who had a complicated postoperative course. The total and wean phase opioid doses for the MTD group were significantly higher than that for the MOR group: 258 versus 22 and 115 versus 6 MMEq/kg; p < 0.001. Duration of opioid exposure was 63 days in the MTD group and 12 days in MOR group (p < 0.001). Subanalysis of the complicated subset also identifies higher total and wean dose for MTD group (293 vs 41 and 116 vs 7 MMEq/kg; p < 0.001) with a longer duration (65 vs 22 days; p = 0.001). Within the subset, LOS was 55% longer in the MTD group than that in the MOR group (150 vs 67 d; p = 0.01) and not different in the uncomplicated group. CONCLUSIONS: After complex NP, a protocolized opioid weaning using MOR versus MTD is associated with 65% shorter opioid duration, 10-fold decreased dose, and shortened LOS.

Hospital outcomes for pediatric heart transplant recipients undergoing tracheostomy: A multi-institutional analysis.

Tracheostomy is associated with increased mortality and resource utilization in children with CHD. However, the prevalence and hospital outcomes of tracheostomy in children with HTx are not known. We describe the prevalence and compare the post-HTx hospital outcomes of pediatric patients with Pre-TT and Post-TT to those without tracheostomy. A multi-institutional retrospective cohort study was performed using the Pediatric Health Information System database. Hospital mortality, mediastinitis, LOS, and costs were compared among patients with Pre-TT, Post-TT, and no tracheostomy. Pre-TT was identified in 29 (1.1%) and Post-TT was identified in 41 (1.6%) of 2603 index HTx hospitalizations. Patients with Pre-TT were younger and more likely to have CHD, a non-cardiac birth defect, or an airway anomaly compared to those without Pre-TT. Pre-TT was not independently associated with increased post-HTx in-hospital mortality. Age at HTx < 1 year, CHD, and Post-TT were associated with increased in-hospital mortality. Pre-TT that occurred during the HTx hospitalization and Post-TT were associated with increased resource utilization. Tracheostomy was not associated with mediastinitis.

Variables Prevalent Among Early Unplanned Readmissions in Infants Following Congenital Heart Surgery.

Medically complex children including infants undergoing cardiac surgery are at increased risk for hospital readmissions. Investigation of this population may reveal opportunities to optimize systems and coordination of care. A retrospective study of all infants undergoing cardiac surgery from 2015 through 2016 at a large tertiary institution who were readmitted within 1 year of discharge from cardiac surgical hospitalization was performed. Data specific to patient characteristics, surgical hospitalization, and readmission hospitalization are described. Unplanned readmissions within 1 year of hospital discharge were analyzed with Cox proportional hazard regression to identify factors associated with increased hazard for earlier unplanned readmission. Comparable to previous reports, 12% (78/658) of all surgical hospitalizations were associated with unplanned readmission within 30 days. Infectious etiology, followed by cardiac and gastrointestinal problems, was the most common reasons for unplanned 30-day readmission. Unplanned readmissions within 2 weeks of discharge were multifactorial and less commonly related to cardiac or surgical care. Primary nasogastric tube feeding at the time of discharge was the only significant risk factor for earlier unplanned readmission (p = 0.032) on multivariable analysis. Increased care coordination with particular attention to feeding and comorbidity management may be future targets to effectively mitigate readmissions and improve quality of care in this population.

Smaller right pulmonary artery is associated with longer survival time without scimitar vein repair.

INTRODUCTION: The optimal management of scimitar syndrome remains incompletely defined. We (1) evaluated the impact of aortopulmonary collateral (APC) occlusion, (2) compared outcomes according to surgical approach for patients who underwent surgery, and (3) identified anatomic factors associated with longer survival time without scimitar vein repair. METHODS: We conducted a single center, retrospective study of 61 patients diagnosed with scimitar syndrome between 1995 and 2019. Right pulmonary artery to total pulmonary artery cross-sectional area (RPA:PA CSA) quantitatively assessed right pulmonary artery size. Anatomical features were analyzed for association with longer survival time without scimitar vein repair. RESULTS: Median follow-up time was 6 years (Q1-Q3, 2-12), with 96% 5-year survival. Twenty-three patients underwent APC occlusion, which significantly decreased symptoms of overcirculation (100%-46%; p = .001) and systolic pulmonary artery pressure (median, 34-29 mmHg; p = .004). Twenty-three patients underwent scimitar vein repair; 5-year freedom from scimitar vein stenosis was 90% among patients who underwent a reimplantation compared with 42% in patients with baffle repair (p = .1). Three patients underwent surgery before the first year of age, with lower 5-year freedom from scimitar vein stenosis (0% vs. 84%; p < .001). On multivariate analysis, a lower RPA:PA CSA was associated with longer survival time without scimitar vein repair (p = .003). CONCLUSIONS: APC occlusion improves the clinical status of young and hemodynamically unstable patients. Repair at an early age is associated with an increased risk of scimitar vein stenosis. Scimitar vein repair might be avoided in patients with a smaller right pulmonary artery.

Midterm outcomes of pulmonary artery sling repair with and without tracheoplasty.

OBJECTIVE: Review a single-centre experience with pulmonary artery sling repair and evaluate risk factors for re-intervention. METHODS: Patients with surgically repaired pulmonary artery sling at a single institution between 1996 and 2018 were retrospectively reviewed. A univariate Cox regression analysis was used to evaluate variables for association with freedom from re-intervention. RESULTS: Eighteen patients had pulmonary artery sling repair. At operation, median age and weight were 6.9 months (interquartile range 4.1-18.1) and 9.5 kg (interquartile range 6.5-14.5), respectively. A median hospital length of stay was 12 days (interquartile range 5.8-55.3). Twelve patients (67%) had complete tracheal rings, of whom six (50%) underwent tracheoplasty (five concurrently with pulmonary artery sling repair). Airway re-intervention was required in five (83%) of the six patients who underwent tracheoplasty. One patient had intraoperative diagnosis and repair of pulmonary artery sling during unrelated lesion repair and required tracheoplasty 24 days post-operatively. One patient died 55 days after pulmonary artery sling repair and tracheoplasty following multiple arrests and re-interventions. Median post-operative follow-up for surviving patients was 6.3 years (interquartile range 11 months-13 years), at which time freedom from re-intervention was 61%. When controlling for patient and tracheal size, initial tracheoplasty was associated with decreased freedom from re-intervention (hazard ratio 21.9, 95% confidence interval 1.7-284.3, p = 0.018). CONCLUSIONS: In patients with pulmonary artery sling, tracheoplasty is associated with decreased freedom from re-intervention. In select patients with pulmonary artery sling and complete tracheal rings, conservative management without tracheoplasty is feasible. Further study is necessary to delineate objective indications for tracheoplasty.

The intraoperative use of recombinant activated factor VII in arterial switch operations.

BACKGROUND: The rate of bleeding complications following arterial switch operation is too low to independently justify a prospective randomised study for benefit from recombinant factor VIIa. We aimed to evaluate factor VIIa in a pilot study. METHODS: We performed a retrospective cohort study of patients undergoing arterial switch operation from 2012 to 2017. Nearest-neighbour propensity score matching on age, gender, weight, and associated cardiac defects was used to match 27 controls not receiving recombinant factor VIIa to 30 patients receiving recombinant factor VIIa. Fisher's exact test was performed to compare categorical variables. Wilcoxon's rank-sum test was used to compare continuous variables between cohorts. RESULTS: Post-operative thrombotic complications were not associated with factor VIIa administration (Odds Ratio (OR) 0.28, 95% CI 0.005-3.77, p = 0.336), nor was factor VIIa administration associated with any re-explorations for bleeding. No intraoperative transfusion volumes were different between the recombinant factor VIIa cohort and controls. Post-operative prothrombin time (10.8 [10.3-12.3] versus 15.9 [15.1-17.2], p < 0.001) and international normalised ratio (0.8 [0.73-0.90] versus 1.3 [1.2-1.4], p < 0.001]) were lower in recombinant factor VIIa cohort relative to controls. CONCLUSIONS: In spite of a higher post-bypass packed red blood cell transfusion requirement, patients receiving recombinant factor VIIa had a similar incidence of bleeding post-operatively. With no difference in thrombotic complications, and with improved post-operative laboratory haemostasis, a prospective randomised study is warranted to evaluate recombinant factor VIIa.

Mandibular Distraction in Robin Sequence With Multi-Level Airway Disease: Always Contraindicated?

In patients with Pierre Robin sequence (PRS), understanding the mechanism of airway obstruction and the potential for concurrent airway lesions is important for determining appropriate intervention. When concomitant airway anomalies are present with PRS, mandibular distraction osteogenesis alone is often contraindicated and unsuccessful at alleviating the obstruction, mandating the need for tracheostomy. Herein, the authors present the second-reported case of PRS with concomitant complete tracheal rings and highlight the importance collaborative surgical efforts to avoid tracheostomy. Our patient was born with signs and symptoms of PRS and concomitant complete tracheal rings. At birth, he developed respiratory compromise that was resistant to invasive and noninvasive intervention and was transferred to our care. The severity of his airway compromise necessitated operative intervention. Due to the patient's complex medical condition, avoiding the long-term sequelae of a tracheostomy and performing mandibular distraction was favorable. However, due to his multi-level airway disease, a 2-staged approach was planned: sliding tracheoplasty to release the tracheal rings, followed by mandibular distraction to correct the micrognathia. The patient tolerated both procedures and was successfully distracted and eventually weaned into room air. When managing patients with PRS in the setting of severe respiratory distress, securing the airway and carefully evaluating for concomitant airway anomalies is crucial. Even in the setting of multi-level airway disease where mandibular distraction is typically contraindicated, by directly addressing each anatomic level of airway obstruction, the airway can be safely secured and the resultant consequences of tracheostomy can be avoided. Careful planning with a multidisciplinary team is essential.

Characteristics and Outcomes of Pediatric Patients Supported With Ventricular Assist Device-A Multi-Institutional Analysis.

OBJECTIVES: The use of ventricular assist devices for pediatric patients with heart failure is increasing, but is associated with significant morbidity and mortality. Our objectives were to describe the admission outcomes and resource utilization of pediatric patients supported with ventricular assist devices, utilizing a multicenter database. DATA SOURCES: Pediatric Health Information System database (comprising 49 nonprofit children's hospitals). STUDY SELECTION: Retrospective cohort analysis of the database from January 2006 to September 2015 for all admissions less than or equal to 21 years old with ventricular assist device implantation. DATA EXTRACTION: The primary outcome was hospital mortality. The secondary outcomes were hospital length of stay and adjusted cost. DATA SYNTHESIS: We analyzed 744 ventricular assist device implantations (740 patients), 422 (57%) males, and 363 (49%) non-Hispanic white. Median age at admission was 5.9 years (interquartile range, 0.9-13.5 yr), and median length of stay was 69 days (interquartile range, 36-122 d). The overall hospital mortality was 188 (25%), whereas 395 (53%) were transplanted and 141 (19%) were discharged on ventricular assist device. Extracorporeal membrane oxygenation was used, in addition to ventricular assist device, in 340 (46%). The majority of ventricular assist device implantations (453, 61%) were from 2011 to 2015 (compared to 2006-2010). More patients discharged on ventricular assist device from 2011 to 2015 (23% vs 13% in 2006-2010; p = 0.001). There was no difference in median age, mortality, length of stay, or adjusted costs between these time periods. On multivariable analysis, underlying congenital heart disease, renal failure, liver congestion, sepsis, cerebrovascular accident, and extracorporeal membrane oxygenation were associated with hospital mortality. Sepsis and ventricular assist device replacement/repair were associated with higher adjusted cost and longer length of stay. CONCLUSIONS: The pediatric ventricular assist device experience continues to grow, with a significant increase in the number of patients undergoing ventricular assist device implantation and a higher proportion being discharged from hospital on ventricular assist device support in recent years. Underlying congenital heart disease, renal failure, sepsis, cerebrovascular accident, and extracorporeal membrane oxygenation are significantly associated with hospital mortality.

Cortisol Response in Children After Second Cardiopulmonary Bypass.

A surge in cortisol levels is seen after surgery with cardiopulmonary bypass (CPB). Based on evidence of attenuation of the cortisol response to repeated stress in other settings, we hypothesized that the magnitude of cortisol increase in children after a second exposure to CPB would be reduced. Serial cortisol levels were measured at three time points after each CPB: immediately (day 0), on the first morning (day 1), and second morning (day 2). Forty-six children underwent two surgeries with CPB during the study period. The mean age (standard deviation) at first and second surgery was 3.5 (6.3) months and 10.4 (9.9) months, respectively. Cortisol levels at the first surgery were 109 (105) µg/dl, 29 (62) µg/dl, and 17 (12) µg/dl on day 0, 1, and 2, respectively; similarly at second surgery, it was 61 (57) µg/dl on day 0 to 20 (16) µg/dl and 11 (10) µg/dl on day 1 and 2, respectively. After log-transformation and adjusting for time interval between surgeries, cortisol levels at the second surgery were lower by 42% on day 0 (p = 0.02), and 46% lower on day 2 (p = 0.02). A second exposure to CPB in children with congenital heart disease is associated with an attenuated cortisol release.

Reoperation after isolated subaortic membrane resection.

BACKGROUND: The resection of a subaortic membrane remains far from a curative operation. We sought to examine factors associated with reoperation and the degree of aortic valve regurgitation as a potential long-term source for reoperation. METHODS: All patients who underwent resection of an isolated subaortic membrane between 1995 and 2018 were included. Patients who underwent other procedures were excluded. Paired categorical data were compared using McNemar's test. Univariate time-to-event analyses were performed using Kaplan-Meier methods with log-rank tests for categorical variables and univariate Cox models for continuous variables. RESULTS: A total of 84 patients (median age 6.6, 31% females) underwent resection of isolated subaortic membrane. At a median follow-up of 9.3 years (interquartile range 0.6-22.5), 12 (14%) patients required one reoperation and 1 patient required two reoperations. Median time to first reoperation was 4.6 years. The degree of aortic valve regurgitation improved post-operatively from pre-operatively (p = 0.0007); however, the degree of aortic valve regurgitation worsened over the course of follow-up (p = 0.010) to equivalence with pre-operative aortic valve regurgitation (p = 0.18). Performance of a septal myectomy was associated with longer freedom from reoperation (p = 0.004). CONCLUSIONS: In patients with isolated subaortic membranes, performance of a septal myectomy can minimise risk for reoperation. Patients should be serially monitored for degradation of the aortic valve, even if aortic regurgitation is not present post-operatively.

Elevated arterial blood pressure after superior cavo-pulmonary anastomosis is associated with elevated pulmonary artery pressure and cerebrovascular dysautoregulation.

BACKGROUND: Elevated arterial blood pressure (ABP) is common after superior bidirectional cavopulmonary anastomosis (BCPA). The effects of elevated ABP after BCPA on cerebrovascular hemodynamics are unknown. We sought to determine the relationship between elevated ABP and cerebrovascular autoregulation after BCPA. METHODS: Prospective, observational study on infants with single-ventricle physiology after BCPA surgery. Continuous recordings of mean ABP, mean cavopulmonary artery pressure (PAP), near-infrared spectroscopy measures of cerebral oximetry (regional cerebral oxygen saturation (rSO2)), and relative cerebral blood volume index were obtained from admission to extubation. Autoregulation was measured as hemoglobin volume index (HVx). Physiologic variables, including the HVx, were tested for variance across ABP. RESULTS: Sixteen subjects were included in the study. Elevated ABP post-BCPA was associated with both, elevated PAP (P<0.0001) and positive HVx (dysautoregulation; P<0.0001). No association was observed between ABP and alterations in rSO2. Using piecewise regression, the relationship of PAP to ABP demonstrated a breakpoint at 68 mm Hg (interquartile range (IQR) 62-70 mm Hg). Curve fit of HVx as a function of ABP identified optimal ABP supporting robust autoregulation at a median ABP of 55 mm Hg (IQR 51-64 mm Hg). CONCLUSIONS: Elevated ABP post-BCPA is associated with cerebrovascular dysautoregulation, and elevated PAP. The effects, of prolonged dysautoregulation within this population, require further study.

Type A interrupted aortic arch and type III aortopulmonary window with anomalous origin of the right pulmonary artery from the aorta.

Interruption of the aortic arch, aortopulmonary window, and anomalous origin of the right pulmonary artery from the ascending aorta are very rare congenital anomalies. It is even rarer to have all three anomalies in the same setting. We present a case of a newborn who was diagnosed with these lesions and describe the primary repair of these anomalies.

Circumflex aorta with double aortic arch in an infant.

Circumflex aorta and double aortic arch are two forms of rare vascular rings. We present a case of an infant who was diagnosed with circumflex aorta and double aortic arch, and describe the surgical management of this rare anomaly.