Congenital high airway obstruction sequence (CHAOS): A new case and a review of phenotypic features

Tracheal agenesis versus tracheal atresia: anatomical conditions, pathomechanisms and causes with a possible link to a novel MAPK11 variant in one case

BACKGROUND

In this study we aimed to describe the morphological and pathogenetic differences between tracheal agenesis and tracheal atresia, which are not clearly distinguished from each other in the literature, and to contribute thereby to the understanding and management of these conditions. Both tracheal agenesis and tracheal atresia represent rare disorders of still unknown aetiology that cannot be detected by prenatal ultrasound. If the affected foetuses survive until birth these conditions result in respiratory failure and in futile attempts to rescue the infant's life.

RESULTS

Autopsies and genetic analyses, including singleton or trio exome sequencing, were performed on five neonates/foetuses with tracheal agenesis and three foetuses with tracheal atresia. Tracheal agenesis was characterized by absence of the sublaryngeal trachea and presence of a bronchooesophageal fistula and by pulmonary isomerism and occurred as an isolated malformation complex or as part of a VACTERL association. Special findings were an additional so-called 'pig bronchus' and a first case of tracheal agenesis with sirenomelia. Tracheal atresia presenting with partial obliteration of its lumen and persistence of a fibromuscular streak resulted in CHAOS. This condition was associated with normal lung lobulation and single, non-VACTERL type malformations. Trio ES revealed a novel variant of MAPK11 in one tracheal agenesis case. Its involvement in tracheooesophageal malformation is herein discussed, but remains hypothetical.

CONCLUSION

Tracheal agenesis and tracheal atresia represent different disease entities in terms of morphology, pathogenesis and accompanying anomalies due to a primary developmental and secondary disruptive possibly vascular disturbance, respectively.

Fetal imaging of congenital lung lesions with postnatal correlation

Congenital lung lesions are a rare group of developmental pulmonary abnormalities that are often first identified prenatally on routine second-trimester US. Congenital pulmonary airway malformation (CPAM) is the most common anomaly while others include bronchopulmonary sequestration, congenital lobar overinflation, bronchogenic cyst and bronchial atresia. Clinical presentation is highly variable, ranging from apparent in utero resolution to severe mass effect with resultant hydrops fetalis and fetal demise. Differentiation among these lesions can be challenging because overlapping imaging features are often present. The roles of the radiologist are to identify key imaging findings that help in diagnosing congenital lung lesions and to recognize any ominous features that might require prenatal or perinatal intervention. High-resolution US and complementary rapid-acquisition fetal MRI provide valuable information necessary for lesion characterization. Postnatal US and CT angiography are helpful for lesion evaluation and for possible surgical planning. This article reviews the embryology of the lungs, the normal prenatal imaging appearance of the thorax and its contents, and the prenatal and neonatal imaging characteristics, prognosis and management of various congenital lung lesions.

Congenital High Airway Obstruction Syndrome (CHAOS): No Intervention, No Survival-A Case Report and Literature Review

Congenital high airway obstruction syndrome (CHAOS) is complete or partial obstruction of the fetal upper airway. CHAOS is a rare and fatal condition if no perinatal intervention is done. Antenatal sonographic imaging has typical findings that can help in an early diagnosis, which is important in deciding elective termination of the pregnancy or successful planning of appropriate perinatal management.

Nonimmune Hydrops Fetalis

Nonimmune hydrops fetalis (NIHF) historically has been considered a lethal fetal condition. Understanding NIHF to be a symptom or an end-stage status of a variety of fetal conditions, along with improved fetal diagnostics and interventions, has changed the landscape for at least some fetuses. Understanding the pathophysiologic mechanisms has led to the development of diagnostic algorithms, improved understanding of cause, and therefore fetal or neonatal treatments. Multidisciplinary counseling and shared decision making are critical to supporting families through pregnancy decisions, potential fetal therapeutic interventions, neonatal management decisions, and at times accepting or transitioning to palliative care.

Congenital high airway obstruction syndrome complicated with foregut malformation and high airway fistula to the alimentary tract – a case series with four distinct types

Background

Congenital high airway obstruction syndrome (CHAOS) is a rare disease and recently has been noticed to show typical prenatal images, such as hyperinflated lungs and flattened or inverted diaphragms. However, in some cases correct diagnosis may be difficult and in such cases the mortality rate increases.

Case presentation

We report four cases of CHAOS complicated with a high airway fistula to the alimentary tract and foregut malformation. The patients did not show the typical features of CHAOS in the fetus. This may be attributed to the high airway fistula acting as a decompression route for the accumulated lung fluids to the alimentary tract.

Conclusion

The combination of CHAOS, foregut malformation and a high airway fistula is very rare and classified into four distinct types: (1) CHAOS with a high airway fistula but not with a foregut malformation; (2) CHAOS with esophageal atresia and tracheoesophageal fistula; (3) CHAOS with a high airway fistula and duodenal atresia; and (4) CHAOS with esophageal atresia, tracheoesophageal fistula and duodenal atresia. It may be useful for treating physicians to be aware of these four distinct types and the typical characteristics of each type.

A system-based approach to the genetic etiologies of non-immune hydrops fetalis

A wide spectrum of genetic causes may lead to nonimmune hydrops fetalis (NIHF), and a thorough phenotypic and genetic evaluation are essential to determine the underlying etiology, optimally manage these pregnancies, and inform discussions about anticipated prognosis. In this review, we outline the known genetic etiologies of NIHF by fetal organ system affected, and provide a systematic approach to the evaluation of NIHF. Some of the underlying genetic disorders are associated with characteristic phenotypic features that may be seen on prenatal ultrasound, such as hepatomegaly with lysosomal storage disorders, hyperechoic kidneys with congenital nephrosis, or pulmonary valve stenosis with RASopathies. However, this is not always the case, and the approach to evaluation must include prenatal ultrasound findings as well as genetic testing and many other factors. Genetic testing that has been utilized for NIHF ranges from standard chromosomal microarray or karyotype to gene panels and broad approaches such as whole exome sequencing. Family and obstetric history, as well as pathology examination, can yield additional clues that are helpful in establishing a diagnosis. A systematic approach to evaluation can guide a more targeted approach to genetic evaluation, diagnosis, and management of NIHF.

Antenatal Ultrasound Diagnosis of Congenital High Airway Obstruction Syndrome: A Case Report and Review of Literature

Congenital high airway obstruction syndrome (CHAOS) is a rare life-threatening fetal condition resulting from obstruction of the upper fetal airway which may be partial or complete. Prenatal diagnosis is crucial as it usually results in stillbirth or death after delivery if unrecognized. We report a case of CHAOS that was diagnosed prenatally due to characteristic ultrasound features. We also briefly review literature in light of current management options.

A rare form of congenital high airway obstruction syndrome and a literature review of ex utero intrapartum treatment

Objective

This is a rare presentation of a fetus with a right mainstem bronchus occlusion leading to congenital high airway obstruction syndrome (CHAOS).

Methods

A review of 15 articles reporting on the use of the ex utero intrapartum treatment (EXIT) procedure.

Results

A total of 22 reported cases of CHAOS had undergone the EXIT procedure from 1994 to 2016. Seventy-seven percent of fetuses that underwent EXIT were alive at the last point of follow-up, but only 36% were alive without any sequelae.

Conclusion

CHAOS is a rare malformation, but after the development of EXIT, survival is a viable option. It is associated with other malformations, but its etiology is entirely unknown.

Clinical presentation and airway management of tracheal atresia: A systematic review

OBJECTIVES

Tracheal atresia (TA) is a rare congenital condition that typically requires an unexpected and emergent resuscitation in the delivery room. The mortality rate associated is very high, with only a few long-term survival cases reported. We describe the findings of a systematic review on the clinical presentation and airway management of TA.

METHODS

Using the keywords "tracheal atresia", "tracheal agenesis" and "tracheal hypoplasia" a search through Embase and Pubmed databases was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) protocol. Articles published from 1950 to 2015 in English, French, Italian, Portuguese and Spanish were included. Exclusion criteria were cases of stillborn, and unclear diagnosis or outcome.

RESULTS

149 cases of TA were identified after reviewing 1125 initial references. There was a male preponderance (65%), and associated malformations were described in 94.2% of patients. Prenatal ultrasound was abnormal in 56.3% of cases, with polyhydramnios being the most common finding. The most frequent type of TA was Faro Type C. 94 (41.3%) patients did not survive beyond the first 24 h of life. Only 13 (8.4%) patients survived more than three months of life, after undergoing a variety of surgical approaches.

CONCLUSION

This review, which to our knowledge is the largest one to date, confirms that TA is a rare malformation, occurs more frequently in males, and has a very high mortality rate. Depending on the presence and type of concomitant malformation, as well of the length of the remaining trachea, different surgical management options are described.

Persistent Left Superior Vena Cava

Persistent left superior vena cava (PLSVC) is a common cardiac anomaly associated with congenital heart diseases. A diagnosis of PLSVC usually warrants a detailed fetal echocardiography. Lesser known associations are the extra cardiac anomalies notably the upper airway and the gastrointestinal tract anomalies. We highlight here the importance of detailed fetal assessment for extra cardiac anomalies in addition to fetal echocardiography in fetuses diagnosed with PLSVC. We hereby present a preterm infant who presented with a triad of PLSVC, laryngeal atresia, and esophageal atresia.

Two case reports of unexpected tracheal agenesis in the neonate: 3 C's beyond algorithms for difficult airway management

Background

Handling neonates with postnatal respiratory failure due to congenital airway malformations implies knowledge about emergency management of unexpected difficult airway. In these stressful situations both technical and communication skills of the caretakers are essential.

Case presentation

Two cases with prenatally unknown tracheal agenesis are reported.

Conclusion

In the presented cases, airway malformation and subsequent difficulties upon endotracheal intubation were not adequately communicated between caretakers. We discuss the aspects of culture, communication, and capnography.

Pregnancy outcomes in severe polyhydramnios: no increase in risk in patients needing amnioreduction for maternal pain or respiratory distress

INTRODUCTION

Polyhydramnios is a common complication of fetal malformations and has been described to have high risk of pregnancy complications such as prematurity and placental abruption. In a subgroup of women severe polyhydramnios may lead to maternal dyspnea or untreatable pain, and amnioreduction is the procedure indicated to relieve those symptoms. There is a lack of information concerning the increase in the risk for the pregnancy when the procedure is indicated. Therefore, this study sought to evaluate the risk of complications in pregnancies with severe polyhydramnios that needed amnioreduction in relation to the basal risk for the pregnancy of having polyhydramnios without the need for the procedure.

MATERIALS AND METHODS

Patients with singleton pregnancies and severe polyhydramnios followed in our fetal medicine center were evaluated retrospectively. Pregnancy complications (prematurity rate, fetal death, premature rupture of membranes, placental abruption and chorioamnionitis) were studied in the group of patients needing the procedure and their risk was compared to the risk of having a pregnancy with severe polyhydramnios but with no need for the procedure.

RESULTS

One hundred and thirty-five patients were evaluated. Forty-four patients (32.6%) needed amnioreduction. There was no increase in the risk of having complications when the procedure was needed OR = 1.4 (CI 0.46-1.26).

CONCLUSION

Amnioreduction performed to relieve maternal symptoms did not statistically increase the risk of pregnancy complications with severe polyhydramnios in single pregnancies.

Congenital high airway obstruction syndrome (CHAOS): discussing the role and limits of prenatal diagnosis starting from a single-center case series

OBJECTIVES

we aimed to report our experience about congenital high airway obstruction syndrome (CHAOS) that is a rare and fatal congenital anomaly; laryngeal atresia is the most frequent cause. Sonographic findings are enlarged echogenic lungs, dilated trachea, and ascites.

METHODS

we performed a single-center case series analysis collecting antenatally through ultrasound examination, and some of them confirmed by autopsy.

RESULTS

we report six cases of CHAOS diagnosed by antenatal ultrasonography between 2007 and 2013.

CONCLUSION

to date literature provides very few individual case reports. This work describes typical sonographic findings of this syndrome and it underlines the importance of early prenatal diagnosis to improve prognosis thought an ex utero intrapartum treatment, that seems to be the only chance of survival for the affected fetus.

Postmortem magnetic resonance appearances of congenital high airway obstruction syndrome

BACKGROUND

Congenital high airway obstruction syndrome (CHAOS) is a rare life-threatening condition characterised by complete or near-complete developmental obstruction of the foetal airway. Although antenatal imaging findings have been described, the postmortem MRI findings have not been reported.

OBJECTIVE

To present postmortem MRI features of CHAOS.

MATERIALS AND METHODS

We retrospectively reviewed our hospital pathology and imaging databases for cases of CHAOS over a 2-year period.

RESULTS

We identified two cases of CHAOS. In both cases, postmortem plain radiographs demonstrated gross abdominal distension with distortion and splaying of the rib cage. Both foetuses had characteristic postmortem MRI findings including large-volume fluid-filled lungs on T2-weighted imaging, diaphragmatic eversion, fluid-filled airway dilatation below the level of obstruction, centrally positioned and compressed heart, and massive ascites. One foetus had an associated limb abnormality.

CONCLUSION

Postmortem MRI in foetuses suspected of having CHAOS allows confirmation of the diagnosis, determination of the anatomical level of the atresia or stenosis, and identification of associated abnormalities without the need for invasive autopsy.