2640 Meters Closer to The Stars: Does High Altitude Affect Fontan Results?

BACKGROUND

Risk factors and postoperative results of the Fontan operation in patients living at high altitude (> 2500 meters above sea level) in the Andean region remains unknown. Evaluate results and risk factor for immediate postoperative outcomes and short- and long-term functional class after Fontan.

METHODS

From June 2003 to February 2019, 104 patients receiving Fontan procedure at 2640 meters (8661 feet) above-sea-level were retrospectively studied. Preoperative catheterization, intraoperative variables and post-operative outcomes were described. Functional class was evaluated in patients living permanently below (Group I) and at or higher than 2500 meters (8202 feet) above sea level. (Group II) Risk factors for mortality were analyzed.

RESULTS

Median age at operation was 8.5 ± 4.4 years; Pulmonary artery pressure 16.2 ± 3.6 mmHg; EDVP 13.3 ± 3.8mmHg, PVRI 2.1(IQR 07-3.7) Wood units. Chest tube duration was 8,5 (6-12) days. Mortality was 4.8%, with 0 in the last 5 years. Higher preoperative pulmonary pressure (16.2 ± 3.6 vs 21.2 ± 3.40mmHg, (P Value 0.01), aortic cross clamp time (P value< 0.001) and renal failure (P value <0.01) were associated with mortality. Functional class improve to class I in 86.4%. Overall survival was 90. 7 % at ten years follow up.

CONCLUSIONS

Increased pulmonary pressure and PVRI are directly related to high altitude. Fontan-Kreutzer operation performed at high altitude in the Andean region is feasible with good results. We routinely fenestrate all cases to avoid dysfunction in the early postoperative period. Functional status is adequate after the operation.

Prediction of pulmonary hypertension using central-to-peripheral pulmonary vascular volume ratio on three-dimensional cardiothoracic CT in patients with congenital heart disease

PURPOSE

To evaluate whether the central-to-peripheral pulmonary vascular volume ratio measured using three-dimensional cardiothoracic CT can serve as a potential predictor of pulmonary hypertension (PH) in patients with congenital heart disease.

METHODS

Cardiothoracic CT was used to quantify right and left total, central, and peripheral pulmonary vascular volumes segmented based on a three-dimensional threshold-based approach in 60 patients with congenital heart disease (group with PH, n = 30; group without PH, n = 30). The CT-based central-to-peripheral pulmonary vascular volume ratios were correlated with the echocardiography-based maximum velocity of tricuspid regurgitation (TR Vmax) and systolic pulmonary arterial pressure (PAP) values. The diagnostic ability of the central-to-peripheral pulmonary vascular volume ratio to predict PH was analyzed.

RESULTS

The central-to-peripheral pulmonary vascular volume ratios were significantly higher in the group with PH compared to the group without PH (1.6 ± 0.9 vs. 0.8 ± 0.3 for the right side, p < 0.001; 2.4 ± 2.2 vs. 1.0 ± 1.4 for the left side, p < 0.004). The right central-to-peripheral pulmonary volume ratios were significantly positively correlated with the TR Vmax and estimated systolic PAP values (R = 0.627 and 0.633, respectively; p < 0.001) in patients with and without PH, while the ratios were moderately correlated with the TR Vmax and estimated systolic PAP values (R = 0.431 and 0.435, respectively; p < 0.020) in the group with PH. The right and left central-to-peripheral pulmonary vascular volume ratios demonstrated a good diagnostic ability for predicting the presence of PH (area under the receiver-operating characteristic curve = 0.867, p < 0.001 and 0.859, p < 0.001 for the right and left, respectively).

CONCLUSION

The CT-based central-to-peripheral pulmonary vascular volume ratio can be used to predict PH in patients with congenital heart disease.

Adults with tetralogy of Fallot show specific features of cerebral small vessel disease: the BACH San Donato study

Life expectancy in adults with congenital heart disease (ACHD) has increased. As these patients grow older, they experience aging-related diseases more than their healthy peers. To better characterize this field, we launched the multi-disciplinary BACH (Brain Aging in Congenital Heart disease) San Donato study, that aimed at investigating signs of brain injury in ACHD. Twenty-three adults with repaired tetralogy of Fallot and 23 age- and sex-matched healthy controls were prospectively recruited and underwent brain magnetic resonance imaging. White matter hyperintensities (WMHs) were segmented using a machine-learning approach and automatically split into periventricular and deep. Cerebral microbleeds were manually counted. A subset of 14 patients were also assessed with an extensive neuropsychological battery. Age was 41.78 ± 10.33 years (mean ± standard deviation) for patients and 41.48 ± 10.28 years for controls (p = 0.921). Albeit not significantly, total brain (p = 0.282) and brain tissue volumes (p = 0.539 for cerebrospinal fluid, p = 0.661 for grey matter, p = 0.793 for white matter) were lower in ACHD, while total volume (p = 0.283) and sub-classes of WMHs (p = 0.386 for periventricular WMHs and p = 0.138 for deep WMHs) were higher in ACHD than in controls. Deep WMHs were associated with poorer performance at the frontal assessment battery (r = -0.650, p = 0.012). Also, patients had a much larger number of microbleeds than controls (median and interquartile range 5 [3–11] and 0 [0–0] respectively; p < 0.001). In this study, adults with tetralogy of Fallot showed specific signs of brain injury, with some clinical implications. Eventually, accurate characterization of brain health using neuroimaging and neuropsychological data would aid in the identification of ACHD patients at risk of cognitive deterioration.

Troubled Judging of Bronchus Compression Due to Contrast-Filled Balloon in Three-Dimensional Rotational Angiography

Three-dimensional rotational angiography (3DRA) is a suitable technique to detect the risk of left main bronchus (LMB) compression during left pulmonary artery (LPA) stenting in partial cavopulmonary connection and total cavopulmonary connection (TCPC). We report on a case of a 4-year-old boy with hypoplastic left heart syndrome and TCPC in which 3DRA and bronchoscopy gave conflicting information on airway patency during balloon interrogation. The balloon with high contrast concentration created a severe artifact impeding visibility of the LMB. Simultaneous flexible bronchoscopy revealed an unobstructed LMB. Repeated 3DRAs with lower contrast concentration had no artifact and showed a patent airway in accordance with the bronchoscopy. Conventional LPA stenting was performed without indication for stent ovalization. The benefit of low contrast concentration in the interrogation balloon was demonstrated in a second case of an 11-year-old boy with TCPC. The margins of the LPA and LMB were clearly visible without blank-out artifact. Oval stent procedure was necessary to prevent LMB compression. When 3DRA is used for vessel-airway interrogation, the balloon contrast concentration should be low in order to avoid artifacts. When in doubt, simultaneous flexible bronchoscopy can overcome the dilemma in airway judgment.

Modeling complex effects of exposure to particulate matter and extreme heat during pregnancy on congenital heart defects: A U.S. population-based case-control study in the National Birth Defects Prevention Study

BACKGROUND/OBJECTIVE

Research suggests gestational exposure to particulate matter ≤2.5 μm (PM2.5) and extreme heat may independently increase risk of birth defects. We investigated whether duration of gestational extreme heat exposure modifies associations between PM2.5 exposure and specific congenital heart defects (CHDs). We also explored nonlinear exposure-outcome relationships.

METHODS

We identified CHD case children (n = 2824) and non-malformed live-birth control children (n = 4033) from pregnancies ending between 1999 and 2007 in the National Birth Defects Prevention Study, a U.S. population-based multicenter case-control study. We assigned mothers 6-week averages of PM2.5 exposure during the cardiac critical period (postconceptional weeks 3-8) using the closest monitor within 50 km of maternal residence. We assigned a count of extreme heat days (EHDs, days above the 90th percentile of daily maximum temperature for year, season, and weather station) during this period using the closest weather station. Using generalized additive models, we explored logit-nonlinear exposure-outcome relationships, concluding logistic models were reasonable. We estimated joint effects of PM2.5 and EHDs on six CHDs using logistic regression models adjusted for mean dewpoint and maternal age, education, and race/ethnicity. We assessed multiplicative and additive effect modification.

RESULTS

Conditional on the highest observed EHD count (15) and at least one critical period day during spring/summer, each 5 μg/m3 increase in average PM2.5 exposure was significantly associated with perimembranous ventricular septal defects (VSDpm; OR: 1.54 [95% CI: 1.01, 2.41]). High EHD counts (8+) in the same population were positively, but non-significantly, associated with both overall septal defects and VSDpm. Null or inverse associations were observed for lower EHD counts. Multiplicative and additive effect modification estimates were consistently positive in all septal models.

CONCLUSIONS

Results provide limited evidence that duration of extreme heat exposure modifies the PM2.5-septal defects relationship. Future research with enhanced exposure assessment and modeling techniques could clarify these relationships.

Mini right axillary thoracotomy for congenital heart defect repair can become a safe surgical routine

OBJECTIVE

Owing to its obvious cosmetic appeal, minimal invasive repair of congenital heart defects (CHDs) through the mini right axillary thoracotomy is becoming routine in many centres. Besides cosmesis, and before becoming a new norm, it is important to establish its outcomes as safe compared to repairs through traditional median sternotomy.

METHODS

Between 2013 and 2021, 116 consecutive patients underwent defect repairs through mini right axillary thoracotomy. Patient, operative data, and hospital outcomes were compared to contemporary mini right axillary thoracotomy and sternotomy series.

RESULTS

There was no mortality or need for approach conversion (mean age 4.3 years, range 0.17-17, mean weight 18.6 kg, range 4.8-74.4) in 118 repairs for atrial septal defect, ventricular septal defect, partial anomalous pulmonary venous return, partial atrioventricular canal with mitral cleft, scimitar syndrome, double-chambered right ventricle, cor triatriatum, and tricuspid valve repair. Protocol included on-table extubation, achieved in 97 children, with 23 outliers leading to 0.7 average hours of mechanical ventilation (range 0-66 hours), indwelling chest drain time of 2.6 days (range 1-9 days), intensive care stay of 1.8 days (range 1-10 days), and hospital stay of 3.9 days (range 2-18 days). Late revisions were required in one patient after scimitar repair for scimitar vein stenosis at 2 weeks, and in another for repair of superior caval vein stenosis after a Warden operation at 2 months; reoperations (5/116 = 4.3%) were successfully performed through the same mini right axillary incision.

CONCLUSIONS

While providing obvious cosmetic advantages, the minimally invasive right axillary thoracotomy approach for the surgical repair of common CHDs yields excellent results and is safe compared to the benchmark median sternotomy approach.

Prenatal and postnatal chromosomal microarray analysis in 885 cases of various congenital heart defects

PURPOSE

This study aimed to evaluate the prevalence of clinically significant (pathogenic and likely pathogenic) variants detected by chromosomal microarray (CMA) tests performed for prenatally and postnatally detected congenital heart defects.

METHODS

A retrospective evaluation of CMA analyses over a period of four years in a single tertiary medical center was performed. Detection rate of clinically significant variants was calculated in the whole cohort, prenatal vs. postnatal cases, and isolated vs. non-isolated CHD. This rate was compared to previously published control cohorts, and to a theoretical detection rate of noninvasive prenatal testing (NIPS; 5 chromosomes).

RESULTS

Of the 885 cases of CHD, 111 (12.5%) clinically significant variants were detected, with no significant difference between the 498 prenatal and the 387 postnatal cases (10.8% vs. 14.7%, p = 0.08). In both groups, the detection rate was significantly higher for non-isolated vs. isolated CHD (76/339 = 22.4% vs. 35/546 = 6.4%, respectively, p < 0.05). The detection rate was higher than the background risk in both groups, including cases of postnatal isolated CHD. 44% of abnormal findings in the prenatal setting would be detectable by NIPS.

CONCLUSION

CMA should be performed for both prenatally and postnatally detected CHD, including postnatal cases of isolated CHD, while NIPS can be considered in specific scenarios.

Estimating the frequency of causal genetic variants in foetuses with congenital heart defects: a Chinese cohort study

BACKGROUND

The belief that genetics plays a major role in the pathogenesis of congenital heart defects (CHD) has grown popular among clinicians. Although some studies have focused on the genetic testing of foetuses with CHD in China, the genotype-phenotype relationship has not yet been fully established, and hotspot copy number variations (CNVs) related to CHD in the Chinese population are still unclear. This cohort study aimed to assess the prevalence of chromosomal abnormalities in Chinese foetuses with different types of CHD.

RESULTS

In a cohort of 200 foetuses, chromosomal abnormalities were detected in 49 (24.5%) after a prenatal chromosome microarray analysis (CMA), including 23 foetuses (11.5%) with aneuploidies and 26 (13.0%) with clinically significant CNVs. The additional diagnostic yield following whole exome sequencing (WES) was 11.5% (6/52). The incidence of total chromosomal abnormality in the non-isolated CHD group (31.8%) was higher than that in the isolated CHD group (20.9%), mainly because the incidence of aneuploidy was significantly increased when CHD was combined with extracardiac structural abnormalities or soft markers. The chromosomal abnormality rate of the complex CHD group was higher than that of the simple CHD group; however, the difference was not statistically significant (31.8% vs. 23.6%, P = 0.398). The most common CNV detected in CHD foetuses was the 22q11.2 deletion, followed by deletions of 5p15.33p15.31, deletions of 15q13.2q13.3, deletions of 11q24.2q25, deletions of 17p13.3p13.2, and duplications of 17q12.

CONCLUSIONS

CMA is the recommended initial examination for cases of CHD in prenatal settings, for both simple heart defects and isolated heart defects. For cases with negative CMA results, the follow-up application of WES will offer a considerable proportion of additional detection of clinical significance.

Predictors of Post-traumatic stress symptomology in parents of infants with Congenital Heart Disease post-surgery and after four months

PURPOSE

To identify predictors of post-traumatic stress symptomology among parents of infants with complex congenital heart defects at hospital discharge and after 4 months.

DESIGN & METHODS

A secondary analysis utilizing data from a larger RCT performed in three pediatric cardiac centers in North America. Analysis included 158 parent-infant dyads. Generalized Linear Modeling was used to identify predictors of parental post-traumatic symptomology at hospital discharge, and after 4 months. Considered predictors included demographics/SES, illness, and psychosocial parameters.

RESULTS

At discharge, parenting stress, education, and infant's medication number were linked to post-traumatic stress symptomology severity; Parenting stress, education, insurance type, and medications number predicted number of symptoms; Tube-assisted feeding predicted PTSD. At 4 months, parenting stress, ethnicity, and number of ED visits predicted PTSS severity; Parenting stress, ethnicity, and cardiologist visits predicted number of symptoms; Parenting stress, single ventricle physiology, and number of children predicted PTSD.

CONCLUSIONS & PRACTICAL IMPLICATIONS

Parental psychosocial factors, additionally to illness and sociodemographic indicators, can potentially risk parents to experience PTSS/PTSD. Nursing and other healthcare professionals can participate in early screening of such factors to determine familial risk.

TRIAL REGISTRATION

NCT01941667.

Associations between ambient heat exposure early in pregnancy and risk of congenital heart defects: a large population-based study

Some epidemiological studies have confirmed the association between environmental factors and congenital heart defects (CHD). While the possibility that maternal ambient heat exposures are related to CHD has received little attention. Our study aims to investigate the association between maternal ambient extreme heat exposure early in pregnancy and the risk of CHD in offspring in China. We conducted a retrospective cohort study of 1,918,105 fetuses between 2 and 8 weeks after gestation from May to October in Guangdong, China, 2015-2019. The main heat exposure was defined as extreme heat events (EHE) by using the 90th (EHE90) or 95th (EHE95) percentile of the daily maximum temperature. For each EHE definition, we further defined four indicators: having EHE or not, frequency, duration, and cumulative days. We used the log-binomial regression models to calculate the prevalence ratios (PR) of CHD with 95% confidence intervals (CI) for the associations between CHD and EHE, adjusted for potentially confounding covariates. There are 1,918,105 infants included in the study, of which 9588 had CHD, with a prevalence rate of 499.9 per 100,000 (95% CI: 489.9, 509.8). We found that all EHE indicators were positively associated with the increased risks of overall CHD, some CHD classes (congenital malformations of cardiac septa, congenital malformations of great arteries, and congenital malformations of great arteries), and some CHD subtypes (atrial septal defect and patent ductus arteriosus). In addition, the PR yielded higher estimates when exposing to EHE95. For instance, the risk of suffering congenital malformations of great arteries was 1.548 (95% CI: 1.401, 1.712) for EHE90 exposure and 1.723 (95% CI: 1.565, 1.898) for EHE95 exposure, respectively. Our study demonstrated that EHE during 2-8 weeks postconception was associated with overall CHD in offspring, particularly atrial septal defects and patent ductus arteriosus. The associations strengthened with the extent and cumulative days of maternal exposure to EHE.

Outcome of ventricular septal defect closure with the Nit-Occlud® Le VSD-Coil: single centre experience

The objective of this study was to review the outcome of patients who underwent transcatheter closure of ventricular septal defect (VSD) using Nit-Occlud^® Leˆ VSD-Coil.A retrospective study was carried out at King Abdulaziz Cardiac Center on all paediatric patients who underwent interventional VSD closure, during the period from 2011 and 2016. Data were collected, including demographic information, cardiac diagnosis, pre-operative diagnosis, intra-operative findings and postoperative events. Out of 46 patients, who were evaluated for VSD device closure, 17 of them were excluded; 24 patients out of 29 had successful closure of VSD using Nit-Occlud Leˆ VSD-Coil (success rate of 83%), and five cases were referred to surgery. The age group was from 2 years up to 18 years. Almost 90% of VSD was the perimembranous (PM) type (26 patients) and 3 patients (10%) with muscular VSD. Ten of the 26 PM VSDs had TV accessory tissue partially covering the VSD defects. The hemodynamic assessment showed pulmonary blood flow to systemic blood flow ratio (Qp:Qs) > 1.5 in almost all the patients who underwent defect closure. Immediate closure of the defect was achieved in 11/24 patients (45%). In five additional patients, there was a tiny residual and eight with a small residual. With 6 months of follow-up, only six patients remained with tiny residual VSD defects.The Nit-Occlud^® Leˆ VSD-Coil device has minimal effects on the aortic and tricuspid valves, and there was no permanent atrioventricular block, especially in patients with PM VSDs. Patients with a residual shunt should be followed, especially for haemolysis.

Correlation of Near-Infrared Spectroscopy Oximetry and Corresponding Venous Oxygen Saturations in Children with Congenital Heart Disease

Invasive and non-invasive monitoring allow for early detection of hemodynamic compromise, facilitating timely intervention and avoidance of further decline. While venous oximetry is useful for assessing the adequacy of systemic oxygen delivery (DO₂), it is most often intermittent, invasive, and costly. Near-infrared spectroscopy (NIRS) oximetry allows for the non-invasive estimation of the adequacy of DO₂. We assessed the correlation between cerebral NIRS oximetry and superior vena cava (SVC) and jugular venous (JV) oxygen saturations and between renal NIRS oximetry and inferior vena cava (IVC) oxygen saturations. Systematic review of the literature was conducted to identify studies with data regarding near-infrared spectroscopy and venous saturation. The PubMed, EMBASE, Medline, and Cochrane databases were queried using the following terms in isolation and various combinations: "congenital heart disease," "near infrared spectroscopy," "venous saturation," and "pediatric." Pediatric studies in which simultaneous NIRS oximetry and corresponding venous oxygen saturations were simultaneously collected after cardiac surgery or catheterization were identified. Data were pooled from these studies to analyze the correlation between NIRS oximetry and the corresponding venous oxygen saturations. A total of 16 studies with 613 patients were included in the final analyses. Data were present to compare cerebral and renal NIRS oximetry with corresponding venous oxygen saturation. Cerebral NIRS and SVC and JV oxygen saturations and renal NIRS and IVC oxygen saturations demonstrated strong degrees of correlation (r-value 0.70 for each). However, cerebral NIRS and IVC oxygen saturation had a week degree of correlation (r-value of 0.38). Pooled analyses demonstrate that cerebral NIRS oximetry correlates strongly with SVC or JV oxygen saturation while renal NIRS oximetry correlates strongly with IVC oxygen saturations. A weak correlation was noted between cerebral NIRS oximetry and IVC oxygen saturations.

Main Physical Features, Echocardiographic and Renal Ultrasonographic Findings of Turner Syndrome in 107 Pediatric Patients

Turner syndrome (TS) is one of the most common malformation syndromes in females. A total number of 107 TS patients, diagnosed between 2000 and 2018, were evaluated for their phenotypic features, and cardiac and renal findings. The mean age of patients at admission was 10.08 ± 4.9 years (range, newborn to 18 years). Four different karyotype groups were encountered, and the most common findings in all groups were short stature, followed by cubitus valgus. Echocardiographic findings of 85 patients were available among which 63 (n = 63/85, 74.1%) were found to be normal. The most common cardiac anomaly was left ventricular outflow tract/aortic arch pathology detected in 9 patients (n = 9/22, 40.9%). Renal malformations were detected in 15 patients (n = 15/84, 17.9%) by renal ultrasonography, and horseshoe kidney was the most common renal malformation, followed by left multicystic dysplastic kidney. There was no significant difference in the frequency of renal malformation and cardiac anomalies among the 4different karyotype groups (χ² exact test, p > 0.05). Compared with the literature, the frequency of renal anomalies was detected at a lower rate. Karyotype analysis should be carried out in all female patients with short stature, even if there are no associated phenotypic findings suggestive of TS. Since cardiac anomalies are frequently seen in TS patients and they represent a common cause of mortality, echocardiography should be carried out as soon as the definite diagnosis is established. Renal anomalies may be less frequent than cardiac anomalies; however, evaluation of TS patients with renal ultrasonography should be done at the time of diagnosis. Although renal ultrasonography can be used as the initial renal screening in TS patients, it may underestimate the frequency of renal malformation; hence, further management may be required.

Placental and fetal characteristics of the Ohia mouse line recapitulate outcomes in human hypoplastic left heart syndrome

Congenital heart defects (CHDs) are the most common birth defect worldwide. The morbidity and mortality associated with these defects is compounded by increased frequency of fetal growth abnormalities. In the Ohia mouse model of hypoplastic left heart syndrome (HLHS), the double homozygous genotype is embryonically lethal at mid-pregnancy; a time in which optimal establishment of the placenta is crucial to fetal survival. We aimed to characterize placental and fetal growth and development in the double heterozygous genotype (Sap130^m/+Pcdha9^m/+). There was a shift in frequency of fetuses with reduced weight near term in the Sap130^m/+Pcdha9^m/+ fetuses compared to wildtype, driven by lower fetal weight in male fetuses compared to female. This shift in fetal weight distribution in the Sap130^m/+Pcdha9^m/+ fetuses was associated with reduced labyrinth region area (P < 0.001) and reduced fetal capillary density (P < 0.001) in the placentas, the latter being significantly lower in male Sap130^m/+Pcdha9^m/+ placentas compared to female. mRNA expression of several nutrient transporters was also lower in placentas from males compared to placentas from females, irrespective of genotype. Overall, this data shows that whilst the double heterozygous fetuses do not carry heart defects, placental development and function is impaired, particularly in males. Such differences are similar to findings in studies of human placentas and highlights the importance of this mouse model in continuing to understand the developmental links and disruptions to the heart-placenta axis.

How does the convergence of prematurity and congenital heart disease impact the developing brain?

Prematurity and congenital heart disease (CHD) are individually associated with increased risk of brain injury and adverse neurodevelopmental outcomes. Delayed brain development in newborns with CHD has been documented to begin in utero and predisposes newborns with CHD to brain injury. Little is known about the combined risks when prematurity and CHD co-occur. The purpose of this review is to highlight the unique vulnerability of preterm newborns with CHD to brain dysmaturation and brain injury, and the urgent need for prospective research.

Genetic evaluation of newborns with critical congenital heart defects admitted to the intensive care unit

Rapid and efficient diagnostics is crucial for newborns with congenital heart defects (CHD) in intensive care unit (ICU) but is often challenging. Given that genetic factors play a role in 20-30% cases of CHD, it is likely that genetic tests could improve both its speed and efficiency. We aimed to analyze the utility of rapid and cost-effective multiplex ligation dependent probe amplification analysis (MLPA) for chromosomal analysis in newborns with critical CHD. One hundred consecutive newborns admitted with critical CHD to the ICU were included in the study. Those with normal MLPA findings were further tested by chromosomal microarray and clinical exome sequencing. Overall, pathogenic/likely pathogenic variants were determined in ten (10%) newborns by MLPA, three (3%) by chromosomal microarray, and three (3%) by clinical exome sequencing. The most common variant detected was deletion of 22q11.2 region.Conclusion: MLPA is fast and cost-effective analysis that could be used as the first-tier test in newborns with critical CHD admitted to the ICU. What is Known: • MLPA is an established method for chromosome analysis in patients with CHD, but detection rate in newborns with critical CHD is unknown. What is New: • Study suggests that detection rate of casual variants using MLPA in newborns with critical CHD is 10%.

Anesthetic Management of a Patient With Ring 18 Syndrome

Ring 18 syndrome or ring chromosome 18 is an extremely rare genetic disorder involving the fusion of the 18th chromosomal ends to form a ring, often with genetic material loss of varying degrees. Although clinical presentation can be extremely variable, characteristic features usually include craniofacial malformations, delayed development, hypotonia, and other skeletal and congenital heart defects. We report the management of a 20-year-old male with ring chromosome 18 who underwent general anesthesia for dental treatment. Clinical manifestations for this patient included intellectual disability, short stature, hypertelorism, flat nasal bridge, micrognathia, a "carp-shaped" mouth, and aortic and pulmonary valve regurgitation. Although mask ventilation and oral intubation were easily performed, nasal intubation was difficult because of rhinostenosis. When providing general anesthesia for a patient with ring chromosome 18, anesthesiologists should evaluate the patient preoperatively for congenital heart defects and prepare for a potential difficult airway.

Access to paediatric cardiac surgery in Colombia: a population-based study

OBJECTIVES

Globally congenital heart disease mortality is declining, yet the proportion of infant deaths attributable to heart disease rises in Colombia and other middle-sociodemographic countries. We aimed to assess the accessibility of paediatric cardiac surgery (PCS) to children <18 years of age in 2016 in the South American country of Colombia.

METHODS

In Bogotá, Colombia, a multi-national team used cross-sectional and retrospective cohort study designs to adapt and evaluate 4 health system indicators at the national level: first, the population with timely geographic access to an institution providing PCS; second, the number of paediatric cardiac surgeons; third, this specialized procedure volume and its national distribution; and fourth, the 30-day perioperative mortality rate after PCS in Colombia.

RESULTS

Geospatial mapping approximates 64% (n = 9 894 356) of the under-18 Colombian population lives within 2-h drivetime of an institution providing PCS. Twenty-eight cardiovascular surgeons report performing PCS, 82% (n = 23) with formal training. In 2016, 1281 PCS procedures were registered, 90% of whom were performed in 6 of the country's 32 departments. National non-risk-adjusted all-cause 30-day perioperative mortality rate after PCS was 2.73% (n = 35).

CONCLUSIONS

Colombia's paediatric population had variable access to cardiac surgery in 2016, largely dependent upon geography. While the country may have the capacity to provide timely, high-quality care to those who need it, our study enables future comparative analyses to measure the impact of health system interventions facilitating healthcare equity for the underserved populations across Colombia and the Latin American region.

Newborn pulse oximetry screening for critical congenital heart defects

We looked at existing recommendations and supporting evidence addressing the effectiveness of pulse oximetry effective for detecting critical congenital heart defects (CCHDs) in newborns. We also looked at the impact of timing of oximetry and the site of testing in the accuracy of screening, and at the potential harms and limitations of pulse oximetry screening,

We conducted a literature search up to the 13^th of August 2019 by using key terms and manual search in selected sources. We summarized the recommendations and the strength of the recommendation when and as reported by the authors. We summarized the main findings of systematic reviews with the certainty of the evidence as reported.

Current evidence supports consistent accuracy for detection of CCHDs in newborns by pulse oximetry screening in addition to antenatal ultrasonography and clinical examination. Overall, early diagnosis of CCHD with pulse oximetry is judged to be beneficial and cost-effective, and potential harms associated with false-positive tests are not serious, while missing CCHDs and other serious diseases detected by hypoxaemia in absence of pulse oximetry screening can lead to serious consequences. The site of testing (post-ductal versus pre- and post-ductal) had no significant effect on sensitivity nor specificity for detection of CCHDs.

Association between maternal exposure to gaseous pollutants and atrial septal defect in China: A nationwide population-based study

BACKGROUND

The association between maternal exposure to gaseous air pollutants and congenital heart defects (CHD) remains unclear. The concentration-response relationship and the time windows of susceptibility to gaseous pollutants may vary by pollutant species and CHD subtypes.

OBJECTIVE

We aimed to examine the relationship between maternal exposures to four species of gaseous pollutants (NO₂, O₃, SO₂, and CO) and atrial septal defect (ASD), which is a common subtype of CHD, and to determine the critical time windows of susceptibility for each gaseous pollutant.

METHODS

Among 1,253,633 infants born between October 1, 2013 and December 31, 2016 in China, 1937 newborns were diagnosed with isolated ASD, a prevalence of 1.55‰. Maternal exposures to the gaseous pollutants were estimated by matching the geocoded maternal addresses with the gridded ambient concentrations. The adjusted odds ratios (aOR) between exposures and ASD were quantified by using mixed-effects logistic regression models.

RESULTS

We found significantly positive associations between ASD and maternal exposures to NO₂, O₃, SO₂, and CO during entire pregnancy, first-, second-, and third-trimester. However, no statistically significant association was found between maternal exposure to PM_2.5, PM_2.5-10 and ASD risk (P > 0.05). In the fully adjusted model with respect to average exposure over entire pregnancy, the adjusted odds ratios (aOR) for each 10 μg/m³ increment of NO₂, O₃, SO₂ were 1.33 (95% CI: 1.22-1.45), 1.13 (95% CI: 1.10-1.16), 1.28 (95% CI: 1.20-1.35), respectively; the aOR for each 100 μg/m³ increment of CO was 1.10 (95% CI: 1.06-1.15). The observed concentration-response relationships varied by exposure periods and pollutants, with the strongest association for NO₂ during the 1st-8th embryology weeks, for O₃ during the third trimester, for SO₂ during the second trimester, and for CO without obvious variation.

CONCLUSIONS

The findings suggest an increased risk of ASD in association with maternal exposures to four common gaseous pollutants. From the perspective of birth defects prevention and ASD risk mitigation, it is critical to reduce maternal exposure to gaseous pollutants especially during the most susceptible time windows.

Gestational exposure to perfluoroalkyl substances and congenital heart defects: A nested case-control pilot study

BACKGROUND

Accumulating evidence suggests that environmental pollutants may contribute to the occurrence of congenital heart defects (CHDs). However, no previous studies have evaluated the impact of perfluoroalkyl substances (PFAS), persistent environmental pollutants, on CHDs. This exploratory study aimed to generate testable hypotheses of the association between gestational PFAS and the risk of CHDs.

METHODS

A nested case-control study was conducted in a cohort of 11,578 newborns. Exposure odds ratios were compared between 158 CHD cases and 158 non-malformed controls delivered at the same hospital, individually matched by maternal age (±5 years) and parity. Concentrations of 27 PFAS, including linear and branched isomers, were determined in maternal peripheral blood and cord blood plasma collected before and during delivery using a ultra-performance liquid chromatography coupled to mass spectrometry. Conditional logistic regression was utilized to evaluate associations between individual PFAS and the risk of CHDs, adjusted for confounding variables.

RESULTS

Maternal gestational exposure to the highly branched perfluorooctanesulfonate (PFOS) isomer potassium 6-trifluoromethyperfluoroheptanesulfonate [6 m-PFOS, adjusted odds ratio (aOR) (95% CI) = 2.47(1.05,5.83)] and perfluorodecanoic acid [PFDA, aOR (95% CI) = 2.33(1.00,5.45)] were associated with increased odds of septal defects with statistical significance, while linear PFOS [aOR (95% CI) = 3.65(1.09,12.16)] and perfluoro-n-dodecanoic acid [PFDoA, aOR (95% CI) = 6.82(1.75, 26.61)] were associated with conotruncal defects. Effect estimates also suggested associations for higher maternal 6 m-PFOS and PFDA concentrations with ventricular septal defect. However, we did not observe these associations in cord blood.

CONCLUSION

These exploratory findings suggested that gestational exposure to most PFAS, especially linear PFOS, 6 m-PFOS, PFDA, and PFDoA, was associated with greater risks for septal and conotruncal defects. However, a larger, adequately powered study is needed to confirm our findings, and to more comprehensively investigate the potential teratogenic effects of other more recently introduced PFAS, and on associations with individual CHD subtypes.

Outcomes of home mechanical ventilation with tracheostomy after congenital heart surgery

OBJECTIVE

After congenital heart surgery, some patients may need long-term mechanical ventilation because of chronic respiratory failure. In this study, we analysed outcomes of the patients who need tracheostomy and home mechanical ventilation.

METHODS

Amongst 1343 patients who underwent congenital heart surgery between January, 2014 and June, 2018, 45 needed tracheostomy and HMV. The median age of these patients was 6.4 months (12 days-6.5 years). Nineteen patients underwent palliation while 26 patients underwent total repair. Post-operative diaphragm plication was performed in five patients (11%). Median duration of mechanical ventilation before tracheostomy was 32 days (8-154 days). The patients were followed up with their home ventilators in ward and at home. Mean follow-up time was 36.24 ± 11.61 months.

RESULTS

The median duration of ICU stay after tracheostomy was 27 days (range 2-93 days). Follow-up time in ward was median 30 days (2-156 days). A total of 12 patients (26.6%) were separated from the ventilator and underwent decannulation during hospital stay. Thirty-two patients (71.1%) were discharged home with home ventilator support. Of them, 15 patients (46.9%) were separated from the respiratory support in median of 6 weeks (1 week-11 months) and decannulations were performed. Total mortality was 31.1%. in which four patients are still HMV dependent. There was no significant difference for decannulation between total repair and palliation patients.

CONCLUSION

HMV via tracheostomy is a useful option for the treatment of children who are dependent on long-term ventilation after congenital heart surgery although there are potential risks.

Procedural Predictors and Outcomes of Percutaneous Secundum Atrial Septal Defect Closure in Children Aged <6 Years

BACKGROUND

Percutaneous atrial septal defect (ASD) closure is the treatment of choice for patients with a suitable ASD anatomy; however, the procedural characteristics and outcomes in children aged <6 years are unclear. The feasibility and safety of percutaneous ASD closure in children aged <6 years was evaluated and the predictors of procedural failure and challenging cases were identified.Methods and Results:Patients from a single center between 2006 and 2018 (n=407) were retrospectively evaluated. There were 265 (65.1%) female patients. The median age at the time of the procedure and ASD size were 3.4 (0.9-5.9) years and 13.3 (3.8-27.0) mm, respectively. Medical records and echocardiographic images were analyzed. A challenging case was indicated by the use of non-conventional techniques. The procedure was completed in 399 patients (98.0%). Post-procedural acute complications occurred in 5 patients, including 1 with device embolization. Two patients underwent surgical device removal. During the follow up (30.3 [3.6-140.8] months), aggravated mitral regurgitation occurred in 5 patients. A multivariate logistic regression revealed large-sized ASD as a predictor of procedural failure (odds ratio=1.828, 95% confidence interval: 1.139-2.934, P=0.012) and challenging cases (odds ratio=1.371, 95% confidence interval: 1.180-1.593, P<0.001).

CONCLUSIONS

Percutaneous ASD closure is feasible and safe in children aged <6 years; however, patients with large-sized ASD are at high risk of procedural failure and becoming a challenging case.