Population-based study of tracheoesophageal fistula and esophageal atresia

Epidemiological characteristics of live births with esophageal atresia in Sao Paulo State, Brazil, from 2005 to 2018

Background

The estimated prevalence of esophageal atresia (EA) is 1 in 2500-4500 live births (LBs). Researchers have already identified risk factors, but the mechanisms are still unknown. The aim of this study is to identify EA prevalence trends and its risk factors in the São Paulo State (SPS) population database.

Methods

We conducted a population-based study using all EA cases identified by the Live Births Information System across 14 years (2005-2018) to estimate EA prevalence trends in recent years, stratified by maternal age and SPS geographical clusters. We calculated the prevalence trends, regression coefficient (β), annual percent change (APC), and 95% confidence interval (CI).

Results

We found 820 EA cases among 8,536,101 LBs with a prevalence of 1.0/10,000 LBs in SPS, Brazil. There was no significant difference in distribution by sex. Among all the cases, the majority (65%) were Caucasian; 51.8% were born at term; 43% had weight of ≥2500 g; 95.4% were singleton; and 73.4% of births were by cesarean section. From 2005 to 2018, there was an increasing trend of EA prevalence (APC=6.5%) with the highest APC of 12.2%. The highest EA prevalence rate (1.7/10,000 LB) was found in the group with maternal age of ≥35 years. No significant seasonal variation was found based on the conception month (p=0.061).

Conclusions

EA had an increasing prevalence trend in SPS, Brazil, in recent years, with the highest prevalence rate in the group with maternal age of ≥35 years. No seasonality was observed. This population-based study is the first to summarize the current epidemiology of EA in SPS LB.

From the Ground Up: Esophageal Atresia Types, Disease Severity Stratification and Survival Rates at a Single Institution

Esophageal atresia (EA), although a rare congenital anomaly, represents one of the most common gastrointestinal birth defects. There is a gap in our knowledge regarding the impact of perioperative critical care in infants born with EA. This study addresses EA types, disease severity stratification, and mortality in a retrospective cohort at a single institution. Institutional Review Board approved our retrospective cross-sectional study of term-born (n = 53) and premature infants (28–37 weeks of gestation; n = 31) that underwent primary surgical repair of EA at a single institution from 2009–2020. Demographic and clinical data were obtained from the electronic medical record, Powerchart (Cerner, London, UK). Patients were categorized by (i) sex, (ii) gestational age at birth, (iii) types of EA (in relation to respiratory tract anomalies), (iv) co-occurring congenital anomalies, (v) severity of disease (viz. American Society of Anesthesiologists (ASA) and Pediatric Risk Assessment (PRAm) scores), (vi) type of surgical repair for EA (primary anastomosis vs. Foker process), and (vii) survival rate classification using Spitz and Waterston scores. Data were presented as numerical sums and percentages. The frequency of anatomical types of EA in our cohort parallels that of the literature: 9.5% (8/84) type A, 9.5% (8/84) type B, 80% (67/84) type C, and 1% (1/84) type D. Long-gap EA accounts for 88% (7/8) type A, 75% (6/8) type B, and 13% (9/67) type C in the cohort studied. Our novel results show a nearly equal distribution of sex per each EA type, and gestational age (term-born vs. premature) by anatomical EA type. PRAm scoring showed a wider range of disease severity (3–9) than ASA scores (III and IV). The survival rate in our EA cohort dramatically increased in comparison to the literature in previous decades. This retrospective analysis at a single institution shows incidence of EA per sex and gestational status for anatomical types (EA type A-D) and by surgical approach (primary anastomosis vs. Foker process for short-gap vs. long-gap EA, respectively). Despite its wider range, PRAm score was not more useful in predicting disease severity in comparison to ASA score. Increased survival rates over the last decade suggest a potential need to assess unique operative and perioperative risks in this unique population of patients. Presented findings also represent a foundation for future clinical studies of outcomes in infants born with EA.

Can 18-years of data from a tertiary referral center help to identify risk factors in esophageal atresia?

BACKGROUND

Esophageal atresia is a complex esophageal malformation with an incidence of 1 in 3,500-4,000 live births, and it usually occurs together with anomalies in other systems or chromosomes. This study aimed to investigate the short-term and long-term results of cases of esophageal atresia retrospectively in our institution and to analyze the factors affecting the outcome.

METHODS

Charts of the patients managed for esophageal atresia in our tertiary pediatric surgery department were investigated retrospectively. Statistical analysis was performed to determine the risk factors for morbidity and mortality.

RESULTS

One hundred and thirteen (95.8%) of 118 cases underwent a single-stage or staged esophagoesophagostomy procedure. In only five of the 40 patients with a long gap between the two atretic ends was an esophageal replacement procedure required. The most common early and late complications were anastomotic stenosis (41.6%) and gastroesophageal reflux (44.9%). In logistic regression analysis, the birthweight (OR [95% CI] = 0.998 [0.997, 0.999], P = 0.001) and preoperative inotrope requirement (OR [95% CI] = 13.8 [3.6-53.3], P < 0.001) were the two risk factors in the mortality prediction model obtained by multivariate analysis. The gap length between the two atretic ends (OR [95% CI] = 1.436 [1.010, 2.041], P = 0.044) and the number of sutures for anastomosis (OR [95% CI] = 1.313 [1.042, 1.656], P = 0.021) were the two risk factors in the gastroesophageal reflux prediction model obtained by multivariate analysis.

CONCLUSIONS

Our study's early and late complication rates were like those found in other studies. Identifying risk factors would be beneficial and might help reduce the severity of potential complications in esophageal atresia patients. Prospective studies on large patient series would help develop registry-based, standardized management protocols.

H-type congenital tracheoesophageal fistula: Insights from 70 years of The Royal Children's Hospital experience

BACKGROUND

The long-term outcomes of H-type tracheoesophageal fistula (TOF), an uncommon variant of esophageal atresia/tracheoesophageal fistula (OA/TOF), are rarely described in the literature. We reviewed our institutional experience of 70 years.

METHODS

The Nate Myers Oesophageal Atresia Database was queried for patients with an H-type TOF (1948-2017). Data included presentation, diagnostic workup, surgical management, and outcomes.

RESULTS

Of 1088 patients with OA/TOF, 56 (5.1%) had an H-type TOF. The most common presenting symptoms were cyanotic episodes (68%), choking with feeds (52%), and aspiration pneumonitis (46%). The majority (82%) were symptomatic in the first week of life. Coexisting congenital anomalies were present in 46%: cardiac (13/56, 23%), genitourinary (10/56, 18%), and vertebral/skeletal (9/56, 16%). Patients were consistently diagnosed with prone contrast tube esophagogram (77% sensitivity on the first study and 96% after a second study). The fistula was most commonly approached through a right cervical collar incision. Right vocal cord palsy occurred in 22%, with one case of bilateral palsies. Other complications included leak (5.6%), recurrence (9.3%), stricture (1.9%), and diverticulum (1.9%). Although there was a trend towards a lower recurrence rate when interposition material was used, this was not statistically significant (3.3% vs 16.7%, p = 0.16). Survival in operative cases was 98.2%, and when all diagnosed cases were considered was 89.3%.

CONCLUSIONS

We have reported the largest single-center series of H-type TOF. Diagnosis is challenging, and surgical morbidity remains high. Despite this, long-term outcomes are favorable.

LEVEL OF EVIDENCE

IV.

Prenatal ultrasonographic findings of esophageal atresia: potential diagnostic role of the stomach shape

Objective

We investigated prenatal sonographic characteristics of esophageal atresia (EA) with advancing gestation. We focused on the degree of polyhydramnios and the stomach shape.

Methods

This study included 27 EA cases (EA group) and 81 idiopathic polyhydramnios cases (non-EA group). The non-EA group consisted of cases without any fetal structural anomaly, musculoskeletal disorder, chromosomal abnormality, or maternal diabetes. Both groups included only singleton pregnancies. Amniotic fluid index (AFI) and width/length (W/L) ratio as well as the product of width and length (W×L) of stomach were serially assessed during gestation and compared between the 2 groups. To predict EA using W/L ratio and W×L, receiver operating characteristic curve analysis was performed.

Results

Polyhydramnios was evident in 77.8% of EA cases. We observed 25.9% and 22.2% EA cases with an absent stomach and a small visible stomach, respectively. After 28 weeks, the EA group manifested significantly higher AFI than the non-EA group. After 32 weeks, W/L ratio in the EA group tended to be lower than that in the non-EA group (32–36 weeks: 1.36 vs. 1.72, P=0.092; >36 weeks: 1.43 vs. 1.63, P=0.024). To predict EA, the calculated area under the curve for W/L ratio was 0.651 after 32 weeks. The diagnosis of EA using a cut-off value of W/L ratio <1.376 showed sensitivity, specificity, positive likelihood ratio, and negative likelihood ratio to be 84.6%, 52.9%, 1.796, and 0.081, respectively.

Conclusion

A low W/L ratio of stomach after 32 weeks with progressive idiopathic polyhydramnios may be used to predict EA.

Histological, immunohistochemical and transcriptomic characterization of human tracheoesophageal fistulas

Esophageal atresia (EA) and tracheoesophageal fistula (TEF) are relatively frequently occurring foregut malformations. EA/TEF is thought to have a strong genetic component. Not much is known regarding the biological processes disturbed or which cell type is affected in patients. This hampers the detection of the responsible culprits (genetic or environmental) for the origin of these congenital anatomical malformations. Therefore, we examined gene expression patterns in the TEF and compared them to the patterns in esophageal, tracheal and lung control samples. We studied tissue organization and key proteins using immunohistochemistry. There were clear differences between TEF and control samples. Based on the number of differentially expressed genes as well as histological characteristics, TEFs were most similar to normal esophagus. The BMP-signaling pathway, actin cytoskeleton and extracellular matrix pathways are downregulated in TEF. Genes involved in smooth muscle contraction are overexpressed in TEF compared to esophagus as well as trachea. These enriched pathways indicate myofibroblast activated fibrosis. TEF represents a specific tissue type with large contributions of intestinal smooth muscle cells and neurons. All major cell types present in esophagus are present-albeit often structurally disorganized-in TEF, indicating that its etiology should not be sought in cell fate specification.

Human exome and mouse embryonic expression data implicate ZFHX3, TRPS1, and CHD7 in human esophageal atresia

INTRODUCTION

Esophageal atresia with or without tracheoesophageal fistula (EA/TEF) occurs approximately 1 in 3.500 live births representing the most common malformation of the upper digestive tract. Only half a century ago, EA/TEF was fatal among affected newborns suggesting that the steady birth prevalence might in parts be due to mutational de novo events in genes involved in foregut development.

METHODS

To identify mutational de novo events in EA/TEF patients, we surveyed the exome of 30 case-parent trios. Identified and confirmed de novo variants were prioritized using in silico prediction tools. To investigate the embryonic role of genes harboring prioritized de novo variants we performed targeted analysis of mouse transcriptome data of esophageal tissue obtained at the embryonic day (E) E8.5, E12.5, and postnatal.

RESULTS

In total we prioritized 14 novel de novo variants in 14 different genes (APOL2, EEF1D, CHD7, FANCB, GGT6, KIAA0556, NFX1, NPR2, PIGC, SLC5A2, TANC2, TRPS1, UBA3, and ZFHX3) and eight rare de novo variants in eight additional genes (CELSR1, CLP1, GPR133, HPS3, MTA3, PLEC, STAB1, and PPIP5K2). Through personal communication during the project, we identified an additional EA/TEF case-parent trio with a rare de novo variant in ZFHX3. In silico prediction analysis of the identified variants and comparative analysis of mouse transcriptome data of esophageal tissue obtained at E8.5, E12.5, and postnatal prioritized CHD7, TRPS1, and ZFHX3 as EA/TEF candidate genes. Re-sequencing of ZFHX3 in additional 192 EA/TEF patients did not identify further putative EA/TEF-associated variants.

CONCLUSION

Our study suggests that rare mutational de novo events in genes involved in foregut development contribute to the development of EA/TEF.

Neonatal Aerodigestive Disorders: Epidemiology and Economic Burden

Aerodigestive disorders, those affecting the upper and lower airway or upper gastrointestinal tract, are interrelated anatomically during fetal development and functionally after birth. Successful respiration and feeding requires careful coordination to promote effective swallowing and prevent aspiration. I describe the epidemiology, including the prevalence of the most common aerodigestive disorders. The ability of an infant to feed by mouth at discharge, without a surgically placed feeding tube, is an important neurodevelopmental marker. Therefore, aerodigestive disorders have a high potential for lifelong morbidities and health care expenditures. When available, published research on related medical costs for these disorders is provided.

Patterns of malformation associated with esophageal atresia/tracheoesophageal fistula: A retrospective single center study

Esophageal atresia/tracheoesophageal fistula (EA/TEF) is one of the most common gastrointestinal birth defects. It can occur in isolation or in association with other birth defects or genetic syndromes. We retrospectively reviewed the EA/TEF cases evaluated at Rady Children's Hospital San Diego (San Diego, CA) between 2007 and 2016. Data were collected for 157 patients. The majority of patients (105, 66.8%) had an associated major malformation present, and 52 patients (33.1%) had isolated EA/TEF. The patients with associated malformations were distributed as follows: 16 patients (10.2%) had a known genetic syndrome (the most common being Trisomy 21 in 11 patients); six patients (3.8%) had a suspected genetic syndrome; one patient had a suspected teratogenic syndrome (diabetic embryopathy); 30 patients had VACTERL association (19.1%); 32 patients had a "partial VACTERL" association (only two VACTERL-type defects without other malformation); nine patients (5.7%) had one additional non-VACTERL-type birth defect, two patients had VACTERL-type defects plus auricular malformations; and nine patients (5.7%) were classified as "unknown syndrome." A classification of the patterns of malformation of patients with congenital EA/TEF is proposed based on reviewing the data of this relatively large and phenotypically diverse patient group.

Suckling, Feeding, and Swallowing: Behaviors, Circuits, and Targets for Neurodevelopmental Pathology

All mammals must suckle and swallow at birth, and subsequently chew and swallow solid foods, for optimal growth and health. These initially innate behaviors depend critically upon coordinated development of the mouth, tongue, pharynx, and larynx as well as the cranial nerves that control these structures. Disrupted suckling, feeding, and swallowing from birth onward-perinatal dysphagia-is often associated with several neurodevelopmental disorders that subsequently alter complex behaviors. Apparently, a broad range of neurodevelopmental pathologic mechanisms also target oropharyngeal and cranial nerve differentiation. These aberrant mechanisms, including altered patterning, progenitor specification, and neurite growth, prefigure dysphagia and may then compromise circuits for additional behavioral capacities. Thus, perinatal dysphagia may be an early indicator of disrupted genetic and developmental programs that compromise neural circuits and yield a broad range of behavioral deficits in neurodevelopmental disorders.

Criticality in tailoring the treatment for tracheoesophageal fistulas in children

OBJECTIVE

Tracheo-oesophageal fistula (TOF) is a rare pathology. It can be congenital and concurrent with other congenital anomalies such as oesophageal atresia, laryngeal and tracheal agenesis, or it can be acquired. The purpose of this study was to analyse various management strategies and their outcomes in infants and children with TOF and identify potential areas for standardisation of the fistula repair procedures.

METHODS

At a single institution, a retrospective analysis of infants and children with congenital or acquired TOF between 2013 and 2019 was performed. Thirteen patients were identified. Data collection included: patient demography, associated congenital anomalies, details of fistula at the time of endoscopy, surgical approach and intra-operative findings, need for additional intervention(s), and outcomes.

RESULTS

Thirteen patients underwent endoscopic or open surgeries for correction of TOF. The TOF was congenital in ten patients and acquired in three patients. Eight patients had associated aero-digestive comorbidities, and six patients had systemic comorbidities. Three patients underwent endoscopic procedures and nine patients underwent an open TOF repair. One patient had tracheal agenesis and was not offered any treatment. Two patients required multiple endoscopic interventions for recurrent TOFs. Among four patients with prior tracheostomy, three were decannulated and one awaits decannulation. Conclusıon Appropriate case selection and surgical ergonomics are essential for patients with TOF to avoid recurrences. Preoperative endoscopy to obtain precise details regarding associated laryngotracheal lesions and demographics of the fistula is crucial.

Outcomes of multi-gestational pregnancies affected by esophageal atresia - tracheoesophageal fistula

BACKGROUND

Contemporary outcomes of infants with esophageal atresia with or without tracheoesophageal fistula (EA/TEF) from multi-gestational pregnancies compared to those of singleton pregnancies have not been reported.

METHODS

A single-center retrospective review of EA/TEF patients born from 1999 to 2013 was performed. Patient demographics, gestational age (GA), birth weight, associated anomalies, requirement for gastrostomy tube and mortality were reviewed.

RESULTS

Singleton EA/TEF patients outnumbered those from multi-gestational pregnancies nearly 10:1 (214 vs 22 patients). EA/TEF patients from multi-gestational pregnancies were more likely to be premature (77% vs. 32%), have lower birth weight (mean 1766 g vs. 2695 g), have associated duodenal atresia (18% vs. 6%) and require gastrostomy tube (41% vs. 33%) for feeding challenges compared to EA/TEF singletons. Mortality was also significantly greater for multi-gestational EA/TEF patients compared to singleton EA/TEF patients (18% vs. 6%).

CONCLUSION

EA/TEF infants from multi-gestational pregnancies have greater clinical complexity and mortality than singleton EA/TEF patients. Parents of EA/TEF multi-gestational infants should be appropriately counseled and supported.

Hypertrophic pyloric stenosis following repair of oesophageal atresia and tracheo-oesophageal fistula in a neonate

Development of hypertrophic pyloric stenosis (HPS) after a few weeks of repair of an oesophageal atresia (OA) and tracheo-oesophageal fistula (TOF) is a rare condition in early infancy. Although vomiting or feeding intolerance in operated cases of OA+TOF are attributed to oesophageal stricture, gastro-oesophageal reflux and oesophageal dysmotility, it may also be caused by HPS. Herein, we report a newborn infant who had OA and TOF operation on day 2 of life and diagnosed to have HPS at 15th day of age. Even though it is a rare anomaly, HPS should be kept on mind in the presence of persistent vomiting following repair of OA.

Population-based birth defects data in the United States, 2010-2014: A focus on gastrointestinal defects

BACKGROUND

Gastrointestinal defects are a phenotypically and etiologically diverse group of malformations. Despite their combined prevalence and clinical impact, little is known about the epidemiology of these birth defects. Therefore, the objective of the 2017 National Birth Defects Prevention Network (NBDPN) data brief was to better describe the occurrence of gastrointestinal defects.

METHODS

As part of the 2017 NBDPN annual report, 28 state programs provided additional data on gastrointestinal defects for the period 2010-2014. Counts and prevalence estimates (per 10,000 live births) were calculated overall and by demographic characteristics for (1) biliary atresia; (2) esophageal atresia/tracheoesophageal fistula; (3) rectal and large intestinal atresia/stenosis; and (4) small intestinal atresia/stenosis. Additionally, we explored the frequency of these malformations co-occurring with other structural birth defects.

RESULTS

Pooling data from all participating registries, the prevalence estimates were: 0.7 per 10,000 live births for biliary atresia (713 cases); 2.3 per 10,000 live births for esophageal atresia/tracheoesophageal fistula (2,472 cases); 4.2 per 10,000 live births for rectal and large intestinal atresia/stenosis (4,334 cases); and 3.4 per 10,000 live births for small intestinal atresia/stenosis (3,388 cases). Findings related to co-occurring birth defects were especially notable for esophageal atresia/tracheoesophageal fistula, rectal and large intestinal atresia/stenosis, and small intestinal atresia/stenosis, where the median percentage of non-isolated cases was 53.9%, 45.5%, and 50.6%, respectively.

CONCLUSIONS

These population-based prevalence estimates confirm some previous studies, and provide a foundation for future epidemiologic studies of gastrointestinal defects. Exploring the genetic and environmental determinants of these malformations may yield new clues into their etiologies.

An epigenetic association of malformations, adverse reproductive outcomes, and fetal origins hypothesis related effects

VACTERL, the prototype for associated congenital anomalies, also has connections with functional issues such as pregnancy losses, prematurity, growth delays, perinatal difficulties, and parental subfertility. This segues into a broader association with similar connections even in the absence of malformations. DNA methylation disturbances in the ovum are a likely cause, with epigenetic links to individual components and to folate effects before conception, explaining diverse fetal and placental findings and providing a link to fetal origin hypothesis-related effects. The association encompasses the following: (1) Pre- and periconceptual effects, with frequent fertility issues and occasional imprinting disorders. (2) Early malformations. (3) Adverse pregnancy outcomes (APOs), as above. (4) Developmental destabilization that resolves soon after birth. This potentiates other causes of association findings, introducing multiple confounders. (5) Long-term fetal origins hypothesis-related risks. The other findings are exceptional when the same malformations have Mendelian origins, supporting a distinct pathogenesis. Expressions are facilitated by one-carbon metabolic issues, maternal and fetal stress, and decreased embryo size. This may be one of the commonest causes of adverse reproductive outcomes, but multifactorial findings, variable onsets and phenotypes, and interactions with multiple confounders make recognition difficult. This association supports VACTERL as a continuum that includes isolated malformations, extends the fetal origins hypothesis, explains adverse effects linked to maternal obesity, and suggests possible interventions.

Repair of congenital esophageal atresia with tracheoesophageal fistula repair in Ontario over the last 20years: Volume and outcomes

BACKGROUND/PURPOSE

This study was designed to determine the volume, postoperative surgical outcomes and, if possible, the relationship between outcome and institutional / surgeon volume in neonates undergoing repair of esophageal atresia with tracheoesophageal fistula (EA-TEF) over the last 20years in Ontario.

METHODS

Using administrative databases, a population based cohort study of patients undergoing EA-TEF repair in Ontario between 1993 and 2012 was conducted.

RESULTS

465 patients with the diagnosis of EA-TEF met inclusion criteria. The mean number of EA-TEF repairs per year per was 5.8. There was a significant difference in hospital annual volume between institutions (range 12.3-3.35: p<0.05). The average number of cases/surgeon for the last 10 study years ranged between 0.5 and 2 cases/year. Primary outcome revealed that repair of recurrent fistula or intestinal interposition was 5.3%, with no reportable difference between institutions. Secondary outcomes revealed that 45.6% underwent dilatation for esophageal strictures, and 19.8% underwent some type of drainage procedure of the chest. These rates were not significantly different between institutions.

CONCLUSION

This study provides insight into the outcomes following EA-TEF repair in Ontario and the difficulty in determining surgeon or institution volume outcome relationships, as both primary and secondary outcome event rates are very low.

LEVEL OF EVIDENCE

2.

Respiratory problems in children with esophageal atresia and tracheoesophageal fistula

Background

Children with congenital esophageal atresia (EA) and tracheoesophageal fistula (TEF) have chronic respiratory symptoms including recurrent pneumonia, wheezing and persistent cough. The aim of this study is to describe the clinical findings of a large group of children with EA and TEF surgically corrected and the instrumental investigation to which they have undergone in order to better understand the patient’s needs and harmonize the care.

Methods

A retrospective data collection was performed on 105 children with EA and TEF followed at Department of Pediatric Medicine of Bambino Gesù Children’s Hospital (Rome, Italy) between 2010 and 2015.

Results

69/105 (66%) children reported lower respiratory symptoms with a mean age onset of 2.2 ± 2.5 years and only 63/69 (91%) performed specialist assessment at Respiratory Unit. Recurrent pneumonia (33%) and wheezing (31%) were the most reported symptoms. The first respiratory evaluation was performed after surgically correction of gastroesophageal reflux (GER) at mean age of 3.9 ± 4.2 years. Twenty nine patients have undergone to chest CT with contrast enhancement detecting localized atelectasis (41%), residual tracheal diverticulum (34%), bronchiectasis (31%), tracheal vascular compression (21%), tracheomalacia (17%) and esophageal diverticulum (14%). Fifty three patients have undergone to airways endoscopy detecting tracheomalacia (66%), residual tracheal diverticulum (26%), recurrent tracheoesophageal fistula (19%) and vocal cord paralysis (11%).

Conclusions

Our study confirms that respiratory symptoms often complicate EA and TEF; their persistence despite medical and surgical treatment of GER means that other etiological hypothesis must be examined and that a complete respiratory diagnostic work up must be considered.

Long-term outcomes following H-type tracheoesophageal fistula repair in infants

PURPOSE

To evaluate outcomes following repair of H-type tracheoesophageal fistula (TEF).

METHODS

Retrospective chart review of infants with H-type TEF treated at our institution between 2000 and 2014. Patient demographics, surgical management, and postoperative function were evaluated.

RESULTS

Of the 268 patients with esophageal atresia/TEF treated at our center, 16 (6%) had an H-type TEF (10 males). Thirteen (81%) had associated anomalies. All patients were symptomatic: choking and sputtering were the most common presentation (n = 10, 63%). Diagnosis Age at diagnosis was 8 days (1 day-34 months). All patients were diagnosed based on a single esophagogram. Prior to surgery, 12 (75%) patients underwent bronchoscopy and 11 underwent cannulation of the TEF tract. Surgery All patients underwent open repair. One was started thoracoscopically but converted to open due to esophageal sero-muscular injury. Repair was achieved in all patients via a transcervical approach (right-sided incision in 15). One patient had an unsuccessful prior attempt at repair using tissue glue. Following TEF division, 11 patients had tissue interposition grafts placed (9 muscle, 2 fat). Postoperative course Eight (50%) patients had postoperative vocal cord paresis (6 right-sided, 2 bilateral). A patient developed recurrent TEF 78 days postoperatively that was subsequently repaired. Follow-up At 41 months (8-143), there were no mortalities, all patients with vocal cord paresis were asymptomatic despite the fact that only 3 of 8 (38%) regained function, and nine (56%) patients had gastro-esophageal reflux requiring treatment.

CONCLUSIONS

This large, single-center series demonstrates that H-type TEF can be diagnosed with esophagogram at an early age. Postoperative recurrent laryngeal nerve paresis and gastro-esophageal reflux disease are common following repair. Although most patients with vocal cord paresis eventually become asymptomatic, two-thirds do not regain vocal cord function. This reinforces the importance of routine examination of vocal cord movement following H-type TEF repair.

Update on Foregut Molecular Embryology and Role of Regenerative Medicine Therapies

Esophageal atresia (OA) represents one of the commonest and most severe developmental disorders of the foregut, the most proximal segment of the gastrointestinal (GI) tract (esophagus and stomach) in embryological terms. Of intrigue is the common origin from this foregut of two very diverse functional entities, the digestive and respiratory systems. OA appears to result from incomplete separation of the ventral and dorsal parts of the foregut during development, resulting in disruption of esophageal anatomy and frequent association with tracheo-oesophageal fistula. Not surprisingly, and likely inherent to OA, are associated abnormalities in components of the enteric neuromusculature and ultimately loss of esophageal functional integrity. An appreciation of such developmental processes and associated defects has not only enhanced our understanding of the etiopathogenesis underlying such devastating defects but also highlighted the potential of novel corrective therapies. There has been considerable progress in the identification and propagation of neural crest stem cells from the GI tract itself or derived from pluripotent cells. Such cells have been successfully transplanted into models of enteric neuropathy confirming their ability to functionally integrate and replenish missing or defective enteric nerves. Combinatorial approaches in tissue engineering hold significant promise for the generation of organ-specific scaffolds such as the esophagus with current initiatives directed toward their cellularization to facilitate optimal function. This chapter outlines the most current understanding of the molecular embryology underlying foregut development and OA, and also explores the promise of regenerative medicine.

Embryonic hypocellularity, blastogenetic malformations, and fetal growth restriction

An association between congenital malformations and fetal growth restriction (FGR) can be largely explained by a relationship with early embryonic hypocellularity. The malformations include the VACTERL association, which is exceptional as a Mendelian syndrome, but is commonly associated with monozygotic twinning, maternal diabetes, and some forms of aneuploidy, all characterized by a small embryo early in development. Parsimony suggests that these different links to VACTERL are related to the hypocellularity as a single common factor, rather than as an expression of three independent pathogenetic processes. A distinct non-genetic pathogenesis is further supported by increased frequencies in the same conditions of a single umbilical artery (SUA), which is also unusual in Mendelian disorders. SUA often involves the atrophy of one artery, which may be facilitated by altered hemodynamics in a smaller embryo, providing a direct link to hypocellularity. Hypocellularity may also explain a possible connection between VACTERL and certain mitochondrial disorders, where reduced energy might slow early cell division and growth, reducing the size of the embryo. © 2016 Wiley Periodicals, Inc.

Esophageal atresia with tracheoesophageal fistula in a patient with 7q35-36.3 deletion including SHH gene

Terminal 7q deletion is rarely reported in the literature. Holoprosencephaly and sacral dysgenesis are found in association with this deletion, due to haploinsufficiency of SHH and HLBX9 genes respectively. We report on a 2-year-old boy with 7q35-36.3 deletion encompassing SHH identified by oligonucleotide array comparative genomic hybridization. In addition to other frequent features, the patient presented with esophageal atresia and tracheoeosophageal fistula diagnosed at birth. This case, together with two others previously described, one presenting with esophageal atresia, the other with congenital esophageal stenosis, confirms the possible association between congenital esophageal malformations and 7q terminal deletion including SHH.

Prevalence and descriptive epidemiology of esophageal atresia in the Russian Federation

BACKGROUND

This study examined the prevalence of esophageal atresia (EA) and the relationship between EA and demographic factors in the Russian Federation.

METHODS

Data were obtained from a population-based congenital malformations registry across 14 years (2000-2013) in 24 regions of the Russian Federation and included cases of EA among live births and stillbirths.

RESULTS

The total number of births was 6,478,706. There were 1317 cases of isolated EA, resulting in a rate of 2.03 (95% confidence interval [CI], 1.92-2.15) per 10,000 births or 1 case per 4926 births. There were differences in the prevalence of EA among regional registries of the Russian Federation. The prevalence of EA during the study period was stable. 57.3% of all cases were cases of EA with tracheo-esophageal fistula (compared with 42.7% of cases without fistula). The male/female sex ratio was 1.3. The relative risk of EA was higher for live births with birth weight less than 3000 g (relative risk [RR] = 2.58 (95% CI, 2.36-2.82), for older maternal age (RR = 1.47 (95% CI, 1.24-1.75), for males (RR = 1.09; 95% CI, 1.03-1.17), and for the first gravidity (RR = 1.17; 95% CI, 1.09-1.25).

CONCLUSION

In this study, the prevalence of EA across different regions of the Russian Federation was analyzed. The prevalence of EA in the period under study remained stable, and the relative risk of EA was associated with maternal age, birth weight and gravidity. Birth Defects Research (Part A) 106:854-859, 2016. © 2016 Wiley Periodicals, Inc.

Comorbid Conditions in Neonates With Congenital Heart Disease

OBJECTIVES

The objectives of this review are to discuss the pathophysiology, clinical impact and treatment of major noncardiac anomalies, and prematurity in infants with congenital heart disease.

DATA SOURCE

MEDLINE and PubMed.

CONCLUSION

Mortality risk is significantly higher in patients with congenital heart disease and associated anomalies compared with those in whom the heart defect occurs in isolation. Although most noncardiac structural anomalies do not require surgery in the neonatal period, several require surgery for survival. Management of such infants poses multiple challenges. Premature infants with congenital heart disease face challenges imposed by their immature organ systems, which are susceptible to injury or altered function by congenital heart disease and abnormal circulatory physiology independent of congenital heart disease. For optimal outcomes in premature infants or in infants with multiple congenital anomalies, a collaborative interdisciplinary approach is necessary.

An assessment of quality of life of operated cases of esophageal atresia in the community

AIMS

To evaluate the outcome of the operated children of esophageal atresia (EA) focusing on their early and late morbidity and mortality and quality of life (QoL) of survivors.

SETTINGS AND DESIGN

A cross-sectional follow-up with retrospective analysis of available medical and surgical records of children who underwent repair for EA.

MATERIALS AND METHODS

The medical records of the children who underwent repair for EA during the period from 2000 to 2011 at the Christian Medical College Hospital, Vellore, were collected retrospectively. Patients with parents were invited to visit the hospital for follow-up and nutritional status, digestive and respiratory symptoms, status of associated anomalies and QoL assessment of children done. QoL assessment was done using the PedsQL™ 4.0 generic core scales questionnaire comprising 4 scale scores: physical, emotional, social functioning, and school functioning. Mean scores are calculated based on a 5-point response scale for each item and transformed to a 0-100 scale with a higher score representing better QoL.

STATISTICAL ANALYSIS USED

Statistical Package for Social Sciences (SPSS) version 16 using Chi-square or Fisher's exact test.

RESULTS

Of 79 patients operated during the said period, there were 10 deaths and a total of 69 (87%) children survived. Of the 66 patients available for follow-up, we interviewed 30 parents and children while for the remaining 36 children, out-patients charts were reviewed retrospectively. Mean follow-up duration was 3.56 years. The height and weight for age measurement showed 47% and 56% of children respectively as below the 5(th) percentile. Main problems faced by operated EA children were of the respiratory (26%) and gastroesophageal (36%) tracts. In spite of the mentioned problems faced, the overall QoL of this group appeared good. In 23 of 30 patients, who answered PedsQL™, more than 70% had scores >85 out of 100 in QoL scoring.

CONCLUSIONS

While survivals of the children born with EA have improved, these children still face nutritional, respiratory, and gastroesophageal problems during their early childhood. In spite of this, the overall QoL of this patient group appears good.

Weekday vs. weekend repair of esophageal atresia and tracheoesophageal fistula

PURPOSE

We hypothesize that weekend esophageal atresia and tracheoesophageal fistula (EA/TEF) repair has worse outcomes compared to procedures performed on weekdays.

METHODS

Kids' Inpatient Database (1997-2009) was searched for EA/TEF in infants admitted at <8days of life. Cases were limited to patients who underwent repair during their hospitalization. Risk-adjusted multivariate analysis (MVA) compared complications, mortality, and resource utilization (length of stay [LOS] total charges [TC]) between weekday and weekend procedures.

RESULTS

Overall, 861 EA/TEF cases with known day of repair were identified. Cohort survival was 96%. On risk-adjusted MVA, complication rates were higher with EA/TEF repair on a weekend (OR: 2.2) compared to a weekday. Additionally, complications (OR: 6.5) and LOS (OR: 9.3) were found to be higher among African American children compared to Caucasians. LOS was higher in patients with Medicaid (OR: 2.4) and repairs performed at non-teaching hospitals (OR: 3.2). Weekend vs. weekday procedure had no significant effect on mortality or resource utilization.

CONCLUSION

By risk-adjusted MVA, increased complication rates for EA/TEF are seen in patients undergoing repair on weekends compared to weekdays. Additionally, African American children experienced higher complication rates compared to Caucasians. LOS after repair varies according to race, payer status, and hospital characteristics.

Respiratory Care of Infants and Children with Congenital Tracheo-Oesophageal Fistula and Oesophageal Atresia

Despite acute respiratory and chronic respiratory and gastro-intestinal complications, most infants and children with a history of oesophageal atresia / trachea-oesophageal fistula [OA/TOF] can expect to live a fairly normal life. Close multidisciplinary medical and surgical follow-up can identify important co-morbidities whose treatment can improve symptoms and optimize pulmonary and nutritional outcomes. This article will discuss the aetiology, classification, diagnosis and treatment of congenital TOF, with an emphasis on post-surgical respiratory management, recognition of early and late onset complications, and long-term clinical outcomes.

Oesophageal atresia and tracheo-oesophageal fistula in Western Australia: Prevalence and trends

AIM

A recent international study reported a higher prevalence of oesophageal atresia with or without tracheo-oesophageal fistula (OA±TOF) in Western Australia (WA). The aim of this study was to examine the prevalence and trends of OA and/or TOF in WA, determine the proportion of cases with associated anomalies and explore the impact of time of diagnosis.

METHODS

The study population comprised all infants born in WA, 1980-2009, and registered with OA and/or TOF on the WA Register of Developmental Anomalies (WARDA).

RESULTS

OA±TOF and TOF alone affect, on average, one in every 2927 births in WA, with a total prevalence of 3.00 and 0.42 per 10 000 births, respectively. The prevalence of OA±TOF increased by 2.0% per annum, with only cases with associated anomalies (64% of cases) demonstrating an increase. TOF rates were stable. Among OA±TOF infants, the proportion of live births, stillbirths and elective terminations of pregnancy for fetal anomaly (TOPFA) was 79%, 6% and 15%, respectively, whereas the majority (94%) of TOF only cases were live births. In 2000-2009, there was 30% fall in OA±TOF live births with 61 (58%) cases diagnosed in first week of life, 10 (9%) prenatally and 34 (32%) at post-mortem only.

CONCLUSIONS

A higher prevalence of OA±TOF in WA was observed with increase over time attributable to increase with associated anomalies. Consistent reporting, availability of prenatal diagnosis and ascertainment of cases following TOPFA or post-mortem examinations can significantly affect prevalence of OA and/or TOF.

One shall become two: Separation of the esophagus and trachea from the common foregut tube

The alimentary and respiratory organ systems arise from a common endodermal origin, the anterior foregut tube. Formation of the esophagus from the dorsal region and the trachea from the ventral region of the foregut primordium occurs by means of a poorly understood compartmentalization process. Disruption of this process can result in severe birth defects, such as esophageal atresia and tracheo-esphageal fistula (EA/TEF), in which the lumina of the trachea and esophagus remain connected. Here we summarize the signaling networks known to be necessary for regulating dorsoventral patterning within the common foregut tube and cellular behaviors that may occur during normal foregut compartmentalization. We propose that dorsoventral patterning serves to establish a lateral region of the foregut tube that is capable of undergoing specialized cellular rearrangements, culminating in compartmentalization. We review established as well as new rodent models that may be useful in addressing this hypothesis. Finally, we discuss new experimental models that could help elucidate the mechanism behind foregut compartmentalization. An integrated approach to future foregut morphogenesis research will allow for a better understanding of this complex process.

Population-based study of esophageal and small intestinal atresia/stenosis

BACKGROUND

The aim of this study was to describe the prevalence of esophageal atresia/stenosis and small intestinal atresia/stenosis in Nagano, Japan, together with associated anomalies, prenatal diagnosis and survival.

METHODS

A population-based cohort study of the prevalence of esophageal atresia/stenosis and small intestinal atresia/stenosis was conducted in Nagano in January 1993-December 2011. The Mann-Whitney test, χ(2) test and Kruskal-Wallis test were used to compare variables. P < 0.05 was considered statistically significant.

RESULTS

In total, 74 cases of esophageal atresia/stenosis and 87 cases of small intestinal atresia/stenosis (31 duodenal, 56 jejuno-ileal) were identified. Prevalences were 1.97 for esophageal atresia/stenosis and 2.23 for small intestinal atresia/stenosis (0.83 for duodenal atresia/stenosis and 1.49 for jejuno-ileal atresia/stenosis) per 10,000 births, respectively. The prevalence of esophageal atresia/stenosis increased significantly from 1993-2001 to 2002-2011 (relative risk [RR], 1.6), as did the prevalences of duodenal atresia/stenosis (RR, 2.2) and jejuno-ileal atresia/stenosis (RR, 3.1). Chromosomal anomalies, particularly trisomy 21, were seen significantly more often in association with duodenal atresia/stenosis (55%) than with esophageal atresia/stenosis (28%, P < 0.01) or jejuno-ileal atresia/stenosis (2%, P < 0.01). The proportion of patients associated with prenatally diagnosed chromosomal anomaly was higher compared to postnatal diagnosis (P < 0.01) in the esophageal atresia/stenosis group.

CONCLUSION

The prevalence of esophageal and small intestinal atresia/stenosis increased significantly from 1993-2001 to 2002-2011. Prenatally diagnosed esophageal atresia/stenosis is associated with multiple anomalies, particularly chromosomal anomalies, compared to other small intestine atresia/stenosis.

Role of SOX2 in foregut development in relation to congenital abnormalities

The uptake of the two essential ingredients for life, oxygen and nutrients, occurs primarily through the oral cavity, but these two lifelines need to be separated with high accuracy once inside the body. The two systems, the gas exchange pulmonary system and the gastro-intestinal feeding system, are derived from the same primitive embryonic structure during development, the foregut, which need to be separated before birth. In certain newborns, this separation occurs not or insufficiently, leading to life threatening conditions, sometimes incompatible with life. The development of the foregut, trachea and lungs is influenced and coordinated by a multitude of signaling cascades and transcription factors. In this review, we will highlight the development of the foregut and pulmonary system and focus on associated congenital abnormalities in light of known genetic alterations with specific attention to the transcription factor SOX2.

The diagnosis of fetal esophageal atresia and its implications on perinatal outcome

The current diagnostic accuracy and perinatal outcome of fetuses with esophageal atresia (EA) continues to be debated. In this review, we report on our experience at a tertiary care fetal center with the prenatal ultrasound diagnosis of EA. Enrollment criteria included a small/absent stomach bubble with a normal or elevated amniotic fluid index between 2005 and 2013. Perinatal outcomes were analyzed and compared to postnatally diagnosed EA cases. Of the 22 fetuses evaluated, polyhydramnios occurred in 73%. Three (14%) died in utero or shortly after birth, but none had EA. In the presence of an absent/small stomach and polyhydramnios, the positive predictive value for EA was 67%. In fetal EA cases confirmed postnatally (group 1, n = 11), there were no differences in gestational age, birthweight, or mortality when compared to postnatally diagnosed infants (group 2, n = 59). Group 1 was associated with long-gap EA, need for esophageal replacement, and increased hospital length of stay. When taken in context with the current literature, we conclude that ultrasound findings suggestive of EA continue to be associated with a relatively high rate of false positives. However, among postnatally confirmed cases, there is an increased risk for long-gap EA and prolonged hospitalization.

A novel treatment approach to H-type esophageal lung in presence of pulmonary artery sling with pneumonectomy and intrathoracic tissue-expander placement

Congenital tracheal anomalies occur in 1:10,000 births and can be associated with congenital cardiac disease. This patient presented with right mainstem atresia, right bronchoesophageal fistula without esophageal atresia (H-type esophageal lung), and left pulmonary arterial (PA) sling. Taking this into consideration, surgical management included right pneumonectomy and placement of expandable prosthesis into the thoracic cavity to buttress the mediastinum and prevent tracheal deviation-induced kinking of the PA sling, which provided pulmonary blood flow to the remaining functional lung. To our knowledge, this is the first reported case of esophageal lung in conjunction with a PA sling, as well as the first documented use of an expandable prosthesis to prevent acute postpneumonectomy syndrome. This case can provide clinicians with increased clinical knowledge for treatment of this rare and potentially lethal combination of congenital anomalies.

A nationwide analysis of clinical outcomes among newborns with esophageal atresia and tracheoesophageal fistulas in the United States

BACKGROUND

The aim of this study was to examine national outcomes in newborn patients with esophageal atresia and tracheoesophageal fistula (EA/TEF) in the United Sates.

METHODS

Kids' Inpatient Database (KID) is designed to identify, track, and analyze national outcomes for hospitalized children in the United States. Inpatient admissions for pediatric patients with EA/TEF for kids' Inpatient Database years 2000, 2003, 2006, and 2009 were analyzed. Patient demographics, socioeconomic measures, disposition, survival and surgical procedures performed were analyzed using standard statistical methods.

RESULTS

A total of 4168 cases were identified with diagnosis of EA/TEF. The overall in-hospital mortality was 9%. Univariate analysis revealed lower survival in patients with associated acute respiratory distress syndrome, ventricular septal defect (VSD), birth weight (BW) < 1500 g, gestational age (GA), time of operation within 24 h of admission, coexisting renal anomaly, imperforate anus, African American race, and lowest economic status. Multivariate logistic regression identified BW < 1500 g (odds ratio [OR] = 4.5, P < 0.001), operation within 24 h (OR = 6.9, P < 0.001), GA <28 wk (OR = 2.2, P < 0.030), and presence of VSD (OR = 3.8, P < 0.001) as independent predictors of in-hospital mortality. Children's general hospital and children's unit in a general hospital were found to have a lower mortality rate compared with not identified as a children's hospital after excluding immediate transfers (P = 0.008).

CONCLUSIONS

BW < 1500 g, operation within 24 h, GA < 28 wk, and presence of VSD are the factors that predict higher mortality in EA/TEF population. Despite dealing with more complicated cases, children's general hospital and children's unit in a general hospital were able to achieve a lower mortality rate than not identified as a children's hospital.

BMP antagonism by Noggin is required in presumptive notochord cells for mammalian foregut morphogenesis

Esophageal atresia with tracheoesophageal fistula (EA/TEF) is a serious human birth defect, in which the esophagus ends before reaching the stomach, and is aberrantly connected with the trachea. Several mouse models of EA/TEF have recently demonstrated that proper dorsal/ventral (D/V) patterning of the primitive anterior foregut endoderm is essential for correct compartmentalization of the trachea and esophagus. Here we elucidate the pathogenic mechanisms underlying the EA/TEF that occurs in mice lacking the BMP antagonist Noggin, which display correct dorsal/ventral patterning. To clarify the mechanism of this malformation, we use spatiotemporal manipulation of Noggin and BMP receptor 1A conditional alleles during foregut development. Surprisingly, we find that the expression of Noggin in the compartmentalizing endoderm is not required to generate distinct tracheal and esophageal tubes. Instead, we show that Noggin and BMP signaling attenuation are required in the early notochord to correctly resolve notochord cells from the dorsal foregut endoderm, which in turn, appears to be a prerequisite for foregut compartmentalization. Collectively, our findings support an emerging model for a mechanism underlying EA/TEF in which impaired notochord resolution from the early endoderm causes the foregut to be hypo-cellular just prior to the critical period of compartmentalization. Our further characterizations suggest that Noggin may regulate a cell rearrangement process that involves reciprocal E-cadherin and Zeb1 expression in the resolving notochord cells.

Second study on the recurrence risk of isolated esophageal atresia with or without trachea-esophageal fistula among first-degree relatives: no evidence for increased risk of recurrence of EA/TEF or for malformations of the VATER/VACTERL association spectrum

BACKGROUND

Esophageal atresia with/without trachea-esophageal fistula (EA/TEF) denotes a spectrum of severe congenital malformations. The aim of this systematic study was to determine both the recurrence risk for EA/TEF, and the risk for malformations of the VATER/VACTERL association spectrum, in first-degree relatives of patients with isolated EA/TEF.

METHODS

A total of 108 unrelated patients with isolated EA/TEF were included. These individuals had 410 first-degree relatives including 194 siblings. The presence of EA/TEF and malformations of the VATER/VACTERL association spectrum in relatives was systematically assessed. Data from the EUROCAT network were used for comparison.

RESULTS

None of the first-degree relatives displayed any form of EA/TEF. In two families, a first-degree relative presented with malformations from the VATER/VACTERL association spectrum. However, no increase in the risk for malformations of the VATER/VACTERL association spectrum was found compared with the control cohort (p = 0.87). In three families, one more distantly related relative presented with EA/TEF.

CONCLUSION

In contrast to previous studies, our results suggest a very low recurrence risk for isolated EA/TEF and/or for malformations of the VATER/VACTERL association spectrum among first-degree relatives.

Type-A long-gap esophageal atresia treated by thoracoscopic esophagoesophagostomy after sequential extrathoracic esophageal elongation (Kimura's technique)

INTRODUCTION

We report four cases of long-gap esophageal atresia (LGEA) treated with thoracoscopic esophagoesophagostomy (TEE) after sequential extrathoracic esophageal elongation (SEEE: Kimura's technique).

METHODS

All initially had gastrostomy, then SEEE. The proximal end of the esophagus was introduced into the apex of the thorax under direct vision during TEE.

RESULTS

Mean birth weight was 1.9 kg. Mean gestational age was 35.0 weeks (range 30-39); mean age at initial esophagostomy was 43.2 days (range 15-110); SEEE was performed for a mean of 3 times (range 2-4) at mean intervals of 5.3 months (range 2-10), with the upper esophageal segment lengthened by a mean of 2.1 cm each time (range 1.1-3.5). Mean age and weight at TEE were 22.3 months and 9.8 kg, respectively. Gap was initially 4.5 vertebrae (range 4-5). Mean operating time was 9.6 h. TEE was successful in 3; 1 required thoracotomy, then re-anastomosis after 11 months of anastomosis leakage; 2 cases with post-TEE anastomosis leakage were treated conservatively. Postoperatively, all cases required fundoplication and esophageal dilatation (2, 3, 5, 8 times, respectively). At mean follow-up of 3.6 years, 2 eat normally and 2 eat minced food.

CONCLUSIONS

TEE after SEEE appears to be a feasible option for treating LGEA.

Specific biochemical amniotic fluid pattern of fetal isolated esophageal atresia

BACKGROUND

Perinatal care of esophageal atresia (EA) may be improved by prenatal diagnosis. Ultrasound findings (polyhydramnios and/or nonvisualization of fetal stomach) lead to a detection rate of ~50%. An amniotic fluid (AF) biochemical pattern characterized by high total protein, γ-glutamyl transpeptidase (GGTP), and normal l-leucine-aminopeptidase (AMP) leads to a 100% detection rate. The aim of this study was to explain this specific pattern.

METHODS

On the basis of enzyme activities assay, the following four objectives were sought: (i) comparing AF markers between EA and other digestive tract atresias, (ii) determining local GGTP synthesis in the esophagus (immunohistobiochemistry), (iii) determining the presence of a specific AF-AMP activity inhibitor, and (iv) comparing AF-AMP and AF-GGTP half-lives.

RESULTS

The AF-EA pattern was similar to that observed in upper duodenal atresia (above the Oddi sphincter). No local synthesis of GGTP was observed in the esophagus. No AF-AMP activity inhibitor was found. AF-GGTP had a longer half-life than AF-AMP.

CONCLUSION

Due to the swallowing anomaly observed in EA, GGTP and AMP values physiologically observed at 18 wk will decrease on the basis of the half-lives of markers, with a flat slope for GGTP and a sharp slope for AMP, therefore explaining the differences observed in the AF-EA pattern.

Poisson versus logistic regression in a descriptive epidemiologic analysis of data from a Birth Defects Registry

BACKGROUND

The objective of this study was to compare results from four statistical approaches to describe the epidemiology of a birth defect.

METHODS

Cases of tracheoesophageal fistula and/or esophageal atresia were selected from the Texas Birth Defects Registry, and live births from Texas birth certificate data. All were delivered in 1999 through 2009. Data on infant and maternal characteristics were taken from the vital record. Four approaches were compared: a cohort design using Poisson regression (PR) and three case-control analyses using logistic regression (LR) with 10 controls per case (LR10), four controls per case (LR4), or affected controls having other birth defects. Analyses were conducted for all 11 years and for just 1 year (2009).

RESULTS

Using all 11 years, there were 869 cases of tracheoesophageal fistula and/or esophageal atresia, and results for PR, LR10, and LR4 were similar. Results using only 2009 were more divergent: PR yielded more statistically significant global tests (type III analyses) and narrower 95% confidence intervals, followed closely by LR10. For both time periods, results using affected controls were different from those using PR and LR.

CONCLUSION

For these descriptive epidemiologic analyses, PR yielded the most precise estimates. However, LR provided similar estimates, and using 10 controls per case yielded precision almost as good as PR.

Normal exon copy number of the GLI2 and GLI3 genes in patients with esophageal atresia

Esophageal atresia (EA) is a congenital developmental defect of the alimentary tract concerning the interruption of the esophagus with or without connection to the trachea. The incidence of EA is 1 in 3000-3500 of live-born infants, and occurs in both isolated and syndromic (in combination with abnormalities in other organ systems) forms. The molecular mechanisms underlying the development of EA are poorly understood. Knockout studies in mice indicate that genes like Sonic hedgehog, Gli2, and Gli3 play a role in the etiology of EA. These facts led us to hypothesize that Sonic hedgehog-GLI gene rearrangements are associated with EA in humans. To test this hypothesis, we screened patients with isolated and syndromic EA for GLI2 and/or GLI3 microrearrangements using methods to estimate the copy number (Multiplex Ligation-dependent Probe Amplification, real-time polymerase chain reaction). To our best knowledge this is the first study assessing copy number of GLI2 and GLI3 genes in patients with EA.