Congenital high airway obstruction syndrome—antenatal diagnosis of a rare case of airway obstruction using multimodality imaging (original) (raw)

Prenatal MRI Findings of Fetuses with Congenital High Airway Obstruction Sequence

Korean Journal of Radiology, 2009

Objective: To define the MRI findings of congenital high airway obstruction sequence (CHAOS) in a series of fetuses. Materials and Methods: Prenatal fetal MR images were reviewed in seven fetuses with CHAOS at 21 to 27 weeks of gestation. The MRI findings were reviewed. The MRI parameters evaluated included the appearance of the lungs and diaphragm, presence or absence of hydrops, amount of amniotic fluid, airway appearance, predicted level of airway obstruction, and any additional findings or suspected genetic syndromes. Results: All the fetuses viewed (7 of 7) demonstrated the following MRI findings: dilated airway below the level of obstruction, increased lung signal, markedly increased lung volumes with flattened or inverted hemidiaphragms, massive ascites, centrally positioned and compressed heart, as well as placentomegaly. Other frequent findings were anasarca (6 of 7) and polyhydramnios (3 of 7). MRI identified the level of obstruction as laryngeal in five cases and tracheal in two cases. In four of the patients, surgery or autopsy confirmed the MRI predicted level of obstruction. Associated abnormalities were found in 4 of 7 (genetic syndromes in 2). Postnatal radiography (n = 3) showed markedly hyperinflated lungs with inverted or flattened hemidiaphragms, strandy perihilar opacities, pneumothoraces and tracheotomy. Two fetuses were terminated and one fetus demised in utero. Four fetuses were delivered via ex utero intrapartum treatment procedure. Conclusion: MRI shows a consistent pattern of abnormalities in fetuses with CHAOS, accurately identifies the level of airway obstruction, and helps differentiate from other lung abnormalities such as bilateral congenital pulmonary airway malformation by demonstrating an abnormally dilated airway distal to the obstruction. ongenital high airway obstruction sequence (CHAOS) is a rare, lifethreatening condition characterized by complete or near complete intrinsic obstruction of the fetal airway. CHAOS has been considered an almost invariably fatal condition (1) which often goes incorrectly diagnosed until autopsy. However, advances in prenatal imaging, earlier diagnosis in utero, in utero surgical treatment, and delivery via ex utero intrapartum treatment (EXIT) to tracheostomy may contribute to improving the outcome of this condition (1-7). With the exception of case reports (2, 8-10), there is little in the literature describing the MRI findings of CHAOS. We present the MRI findings in a series of seven fetuses with prenatal diagnosis of CHAOS. To our knowledge, this is the largest described series of patients with CHAOS and the first article focusing on the description of MRI findings.

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.

Congenital high airway obstruction syndrome: MR/US findings, effect on management, and outcome

Pediatric Radiology, 2008

Congenital high airway obstruction syndrome (CHAOS) is a rare disorder defined as any fetal abnormality that obstructs the larynx or trachea. Prompt airway intervention at delivery after accurate prenatal diagnosis may allow survival of this otherwise fatal condition. To identify prenatal MRI findings in CHAOS, to compare these findings with those of fetal US, to determine if imaging alters diagnosis and management decisions, and to correlate prenatal with postnatal imaging findings. Records and MRI scans of ten fetuses with CHAOS were reviewed, and the findings correlated with outside and same-day fetal US and postnatal imaging findings. Fetal lung volumes were measured on MRI scans. Large lung volumes were found in 90% of the fetuses. Increased lung signal intensity, inverted diaphragm, and a dilated, fluid-filled lower airway were identified in all. The obstruction level was identified in 90%. MRI changed screening US diagnosis in 70%, but was concordant with the tertiary care US imaging in 90%. Seven fetuses were terminated or died in utero, and three fetuses survived after ex utero intrapartum tracheostomy placement. Autopsy or bronchoscopy performed in 60% confirmed CHAOS. Postnatal chest radiographs and CT showed hyperinflation, while US and fluoroscopy showed diminished diaphragmatic motion. MRI demonstrates large lung volumes, increased lung signal intensity, inverted diaphragm, and dilated fluid-filled lower airway, and usually identifies the obstruction level. The degree of correlation between MRI and tertiary prenatal US is high, but CHAOS is frequently misdiagnosed on screening US. Correct diagnosis may enable planned airway management. Voluminous lungs and diaphragmatic abnormalities persist on postnatal imaging.

Congenital high airway obstruction syndrome (CHAOS): A potential for perinatal intervention

Journal of Pediatric Surgery, 1994

0 Congenital high airway obstruction syndrome (CHAOS) results in a predictable constellation of findings: large echogenie lungs, flattened or inverted diaphragms, dilated airways distal to the obstruction, and fetal ascites and/or hydrops. The authors report on four fetuses referred for evaluation. None of them survived. Postmortem evaluation showed that three fetuses had laryngeal atresia, and one had tracheal stenosis. Coexistent fetal anomalies were accurately diagnosed by ultrasound in three of the four patients. The finding of CHAOS on prenatal ultrasound examination is diagnostic of complete or near-complete obstruction of the fetal upper airway, most likely caused by laryngeal atresia. A greater understanding of the natural history of CHAOS may permit improved prenatal and perinatal management.

Prenatal diagnosis of congenital high airway obstruction syndrome (CHAOS). Five case report

Medical ultrasonography, 2015

Congenital high airway obstruction syndrome (CHAOS) is an extremely rare life-threatening condition. Laryngeal atresia appears to be the most frequent cause. Generally the diagnosis is made with severely enlarged and highly echogenic lungs and additional ultrasound findings. The prognosis of the affected infants is often poor. Five cases are reported here that were diagnosed in a tertiary center between 2008 and 2014.

Case report Prenatal diagnosis of congenital high airway obstruction syndrome (CHAOS). Five case report

2020

Congenital high airway obstruction syndrome (CHAOS) is an extremely rare life-threatening condition. Laryngeal atresia appears to be the most frequent cause. Generally the diagnosis is made with severely enlarged and highly echogenic lungs and additional ultrasound findings. The prognosis of the affected infants is often poor. Five cases are reported here that were diagnosed in a tertiary center between 2008 and 2014.

More or less CHAOS: case report and literature review suggesting the existence of a distinct subtype of congenital high airway obstruction syndrome

Ultrasound in Obstetrics & Gynecology, 2007

Congenital obstruction of the upper airway (CHAOS) is a rare, usually lethal abnormality. A literature review of 36 prenatally diagnosed cases of CHAOS and the analysis of our own case suggest the existence of a distinct subtype of CHAOS, raising important implications for diagnosis and management. Serial fetal ultrasound examinations at 17–23 weeks' gestation showed hyperechoic and enlarged lungs, mediastinal shift, flattened diaphragm, polyhydramnios and apparently fluid‐filled esophagus, findings interpreted as bilateral cystic adenomatoid malformation Type III. Ultrasound findings normalized around 32 weeks. The diagnosis of CHAOS was made after birth at term by direct laryngoscopy prompted by ventilatory difficulties and failed attempts at intubation. A pinhole opening posterior to the cricoid cartilage allowed the passage of an endotracheal tube. Based on observations in our case and those of five similar cases in the literature, we describe for the first time a subtype of...

A rare case report of congenital high airway obstruction syndrome presenting in a 23 weeks foetus

International Journal of Reproduction, Contraception, Obstetrics and Gynecology

Congenital High Airway Obstruction Syndrome or CHAOS is a blockage of the foetus’s trachea or larynx due to many factors including narrowing of the airway, a web-like membrane or even tracheal atresia. In the uterus, the foetal lungs constantly produce fluid and as a result of this airway blockage in the trachea, the lung fluid cannot escape out of the foetal mouth. Because of this the foetus’s lungs become distended with fluid and over distended lungs can put pressure on the heart and affect the heart’s ability to function. If the heart cannot function effectively hydrops or congestive heart failure can occur. We present a rare case of CHAOS diagnosed prenatally at about 23 weeks by USG in our hospital.

Prenatal Diagnosis and Outcome of Tracheal Agenesis as Part of Congenital High Airway Obstruction Syndrome. Case Presentation and Literature Review

Medicina, 2021

Tracheal atresia is an extremely rare condition whereby a partial or total obstruction of the trachea is seen. It is almost always lethal, with just a handful of cases that ended with a good outcome. In this study we report on a 15-week male fetus, diagnosed with hyperechogenic lungs, midline heart position and inverted diaphragm. Sonographic findings suggest congenital High Airway Obstruction Syndrome (CHAOS) An ultrasound scan and fetal MRI were not able to point out the exact obstruction level. In spite of extensive counselling, the parents opted to carry on with the pregnancy. Fetal demise was noted on a scan at 19 weeks gestation. After the elective termination of pregnancy, a post-mortem examination showed partial tracheal atresia with no other anomalies. Despite technological progress in CHAOS syndrome, a precise diagnosis and accurate prognosis remain elusive.

Congenital high airway obstruction syndrome: natural history and management

Journal of Pediatric Surgery, 2003

Background: Congenital high airway obstruction syndrome (CHAOS) is a life-threatening condition with a poorly understood natural history. Methods: A retrospective review of five patients with CHAOS between 1997 and 2002 was performed. Results: All fetuses had large echogenic lungs, dilated airways, inverted diaphragms, and massive ascites. One fetus with a laryngeal cyst was terminated at 22 weeks. A twin fetus with findings suggestive of a tracheal web had progressive hydrops, which led to fetal demise. The remaining 3 patients delivered via the ex utero intrapartum treatment (EXIT) procedure survived. The first patient tolerated progressive hydrops for 12 weeks in utero. He had tracheal atresia but underwent laryngotracheoplasty successfully. He is the first long-term CHAOS survivor and is speaking at 5 years of age. The 2 patients with relatively stable lung volumes prenatally have laryngeal atresia with a pinpoint posterior laryngeal fistula. Their postnatal clinical courses were much more benign than the first survivor. Conclusions: The prenatal natural history and postnatal course of CHAOS depends on whether the airway obstruction is complete. The EXIT procedure offers the potential for salvage of this otherwise lethal condition. Hydrops may be well tolerated prenatally for weeks with potential resolution if airway fistulization is present.