Laryngeal atresia is a rare congenital condition that presents with hypoxia and failed intubation attempts at birth. When diagnosed prenatally, options exist to obtain airway access during delivery. However, postnatal diagnosis requires a high degree of clinical suspicion and the prompt initiation of surgical airway management in order to avoid morbidity and mortality.

BACKGROUND: Congenital high airway obstruction syndrome (CHAOS) is a rare condition that can progress to fetal hydrops and demise in utero or at birth unless interventions are undertaken to alleviate the tracheal obstruction. While the ex-utero intrapartum treatment (EXIT) procedure for airway stabilization is technically feasible, abnormal pulmonary development as a result of the antenatal obstructive process may result in severe postnatal respiratory complications.
METHODS: We describe a case of CHAOS with secondary hydrops treated in utero at 24 0/7 weeks\' gestation by fetoscopic tracheal decompression via laser perforation of the airway obstruction. Interval imaging after the fetoscopic operation demonstrated resolution of the fetal hydrops. Tracheostomy for airway stabilization was performed at the time of the EXIT procedure near term (36 0/7 weeks). The patient underwent tracheal reconstruction and decannulation at 3 years of life.
CONCLUSIONS: The primary goal of fetoscopic airway evaluation and intervention is not necessarily to perform definitive stabilization of the airway but rather to achieve sufficient decompression of the trachea to reverse fetal hydrops and salvage pulmonary development. In utero fetoscopic treatment may allow for prolongation of the pregnancy with delivery at or near term via EXIT procedure for definitive neonatal airway stabilization.

BACKGROUND: Without fetal or perinatal intervention, congenital high airway obstruction syndrome (CHAOS) is a fatal anomaly. The ex utero intrapartum treatment (EXIT) procedure has been used to secure the fetal airway and minimize neonatal hypoxia but is associated with increased maternal morbidity.
METHODS: A 16-year-old woman (gravida 1, para 0) was referred to our hospital at 31 weeks gestation with fetal anomalies, including echogenic lungs, tracheobronchial dilation, and flattened diaphragms. At 32 weeks, fetoscopic evaluation identified laryngeal stenosis, which was subsequently treated with balloon dilation and stent placement. The patient developed symptomatic and regular preterm contractions at postoperative day 7 with persistent sonographic signs of CHAOS, which prompted a repeat fetoscopy with confirmation of a patent fetal airway followed by Cesarean delivery under neuraxial anesthesia. Attempts to intubate through the tracheal stent were limited and resulted in removal of the stent. A neonatal airway was successfully established with rigid bronchoscopy. Direct laryngoscopy and bronchoscopy confirmed laryngeal stenosis with a small tracheoesophageal fistula immediately inferior to the laryngeal stenosis and significant tracheomalacia. A tracheostomy was then immediately performed for anticipated long-term airway and pulmonary management. The procedures were well tolerated by both mom and baby. The baby demonstrated spontaneous healing of the tracheoesophageal fistula by day of life 7 with discharge home with ventilator support at 3 months of life.
CONCLUSIONS: Use of repeated fetoscopy in order to relieve fetal upper airway obstruction offers the potential to minimize neonatal hypoxia, while concurrently decreasing maternal morbidity by avoiding an EXIT procedure. Use of the tracheal stent in CHAOS requires further investigation. The long-term reconstruction and respiratory support of children with CHAOS remain challenging.

Congenital high airway obstruction syndrome (CHAOS) is a rare congenital malformation, which results from deficient recanalization of the upper airways. Laryngeal atresia is the most common cause, other etiologies being trachea atresia, laryngeal or tracheal webs, subglottic stenosis, obstructing laryngeal cysts, and laryngeal or tracheal agenesis. There is decreased clearance of the fluid produced by fetal lungs due to obstruction leading to increased intratracheal pressure and thereby secondary proliferative lung growth. The heart becomes compressed in the midline due to hyperexpansion of the lungs causing elevated intrathoracic pressure, decreased venous return, and fetal cardiac failure. This sequence causes ascites, placento-megaly, and eventually hydrops fetalis. We present a case of antenatal diagnosis of a fetus with CHAOS corroborated by fetal autopsy.

Detailed assessment of the larynx is not easy because of its complex structures and the associated technical difficulties. We performed sonography in multiple planes to assess the laryngeal anatomy and movements of a fetus with laryngeal atresia. The distended trachea ended abruptly with an echogenic non-structured larynx which showed shallow rapid \"flutter-like\" movements and up and down but not adduction- abduction movements during swallowing. Shadowing from the chin could be reduced by scanning through fluid in the oral cavity or between the transverse processes of vertebrae in a coronal plane.

Congenital High Airway Obstruction Syndrome is a rare pathology that may conduct the baby to death shortly after delivery. This outcome may cause emotional distress in the parents but it may also generate expensive medical malpractice claims about the reasons why the syndrome was not identified and/or correctly treated. The authors conducted a review of the cases in which Congenital High Airway Obstruction Syndrome caused death of the baby shortly after delivery. Then, they pointed out these ultrasonographic and anatomical reasons why the syndrome may be not identified and/or correctly treated: negative prenatal ultrasonography, recurrence of non-specific findings at prenatal ultrasonography, connection of respiratory and gastrointestinal tracts, tracheal agenesis or atresia, parent\'s refuse of post-partum therapeutic procedures, multiple malformations of the fetus/child. In conclusion, the authors highlighted that death shortly after delivery is usually caused by specific conditions that are not influenced by healthcare team\'s practice.

Background: Congenital High Airway Obstruction Syndrome (CHAOS) is an uncommon anomaly. Prenatal ultrasonography allows a prenatal diagnosis to prepare for immediate surgical correction at birth. If the obstruction is severe and a correct therapeutic approach is not planned, CHAOS can cause neonatal death shortly after delivery from a potentially surgically correctable lesion.Case report: This neonate died unexpectedly shortly after delivery due to CHAOS. Ultrasonographic findings of enlarged echogenic lungs, dilated airways distal to the obstruction, flattened or inverted diaphragms, or ascites were absent. This was due to a type-II laryngeal-atresia and a type-C esophageal-atresia, with a resultant distal fistula that allowed intrauterine decompression of the fluid in the lungs.Conclusions: The absence of prenatal ultrasonographic findings of CHAOS may be due to a lower fistula between respiratory and gastrointestinal tracts. This set of associations may not be a surgically correctable cause of CHAOS.

We present a case of prenatal hydrops secondary to congenital high airway obstruction syndrome (CHAOS) that was treated with fetoscopy-assisted needle decompression. A 22-year-old G3P2 woman presented after a 21-week ultrasound demonstrated CHAOS. The fetus developed hydrops at 25 weeks, characterized by abdominal ascites, pericardial effusion, and scalp edema. Fetal MRI showed complete obstruction of the glottis and subglottic airway, suggestive of laryngeal atresia. At 27 weeks, due to the progression of the hydrops, operative fetoscopy was proposed and performed. Fetal laryngoscopy confirmed fusion of the vocal cords and laryngeal atresia. The atretic segment was a solid cartilaginous block, preventing intubation. Using the fetoscope to stabilize the fetal head and neck, we performed ultrasound-guided percutaneous needle drainage of the cervical trachea through the anterior fetal neck. We removed 17 mL of viscous fluid from the lower trachea, resulting in immediate lung decompression. Two weeks later, ultrasound confirmed hydrops resolution. The patient was delivered and tracheostomy performed at 30 weeks via an ex utero intrapartum treatment (EXIT) procedure after progression of preterm labor. At 27 days of life, the infant was stable on minimal ventilator support. To our knowledge, this is the first successful report of an ultrasound-guided percutaneous tracheal decompression through the anterior neck of a fetus with CHAOS secondary to laryngeal atresia.

OBJECTIVE: The aim of this study was to evaluate the indications and the clinical outcomes of the fetuses managed with ex utero intrapartum treatment (EXIT) procedures.
METHODS: We retrospectively reviewed the medical records of all fetuses who underwent EXIT procedures between 2003 and 2018.
RESULTS: EXIT procedures were performed in nine cases. The prenatal diagnosis of the neonates was congenital high airway obstruction syndrome in four cases, the neck masse in five cases. Although the airway management under the EXIT procedure was successful in eight cases, the airway management failed in one case. During the EXIT procedures, the airway was managed by endotracheal intubation in two cases, whereas six cases underwent tracheostomy. Six cases with fetal airway obstruction survived to discharge, whereas three cases died due to airway management failure or complications of the underlying disease. A case with a cervical teratoma underwent tumor resection the day after birth due to rapid enlargement of the neck mass. Long-term survival was achieved in five cases.
CONCLUSIONS: We concluded that the EXIT procedure was effective and could be performed safely in the airway management of fetuses with suspected airway obstruction. The treatment strategy for the neck masses should be planned before birth.

Congenital high airway obstruction syndrome (CHAOS) is a rare sequence due to a complete obstruction of the fetal airway that blocks the larynx or trachea, either intrinsic atresia or extrinsic compression (e.g., congenital neck mass). Despite the true incidence of CHAOS is unknown, an incidence of 1 per 50,000 newborns is described. If any obstruction occurs in the tracheobronchial airway, this secretion cannot be extricated. Because of this situation, a knock-on effect starts: the enlargement of the lungs squeezes the heart and great veins, what results in a replacement of the heart to the center of the chest becoming small and dysfunctional. Decreased venous return and the failure of cardiovascular system end in ascites and hydrops. The diaphragm planes or inverts according to the severity of the process. In case of unrecognized syndrome during the prenatal period, it usually results in stillbirth or death shortly after delivery. The overall prognosis remains fatal, and long-term medical and surgical challenges for survivors remain considerable even after overcoming fetal intervention.