congenital high airway obstruction syndrome

Congenital high airway obstruction syndrome (CHAOS) is a rare and life-threatening fetal condition characterized by a complete or partial blockage of the upper airway. Laryngeal atresia is the most frequently observed cause, although other structural abnormalities such as laryngeal cysts, subglottic stenosis, tracheal atresia, or even agenesis may also lead to this condition. The disorder is typically detected during prenatal imaging and is primarily recognized in the fetal period, with significant implications for neonatal respiratory function. As precise prevalence estimates are not available, understanding of its frequency is limited.

The clinical features of congenital high airway obstruction syndrome primarily center on the obstruction of the fetal airway. Prenatal imaging may reveal signs such as enlarged, fluid-filled lungs or other indicators of airway blockage, which raise concern for this condition. After birth, affected infants might experience severe respiratory distress due to the inability to establish an effective airway. Not all individuals experience the same degree of obstruction, and severity can vary considerably.

The underlying cause of congenital high airway obstruction syndrome involves developmental anomalies affecting the upper airway. Laryngeal atresia is the most common etiology, although other airway malformations such as laryngeal cysts, subglottic stenosis or atresia, tracheal atresia, and agenesis of the larynx or trachea have been implicated. The precise genetic basis is not yet established, and inheritance patterns have not been clearly defined, suggesting that the condition may result from complex developmental factors.

Currently, management of congenital high airway obstruction syndrome focuses on supportive care and symptom management rather than any treatment specifically approved for the condition. At birth, establishing a secure airway is critical, often necessitating emergency interventions by a multidisciplinary team that may include neonatologists and pediatric otolaryngologists. Supportive measures are tailored to each individual’s needs, and families are encouraged to discuss options with their healthcare providers to determine the best approach. Genetic counseling may also be considered to help families understand the condition and evaluate future family planning options.

The prognosis for congenital high airway obstruction syndrome varies widely depending on the severity and specific anatomical features present. With current standards of care and advances in neonatal supportive treatments, some affected infants have experienced improved outcomes. However, due to the life-threatening nature of the airway obstruction, many cases remain challenging, and outcomes are highly variable. Outcomes described in medical literature continue to evolve as standards of care improve, and families should consult with specialized care teams and genetic counselors for personalized guidance.

Clinical trials are underway exploring new treatment approaches for congenital high airway obstruction syndrome. Individuals interested in clinical trials are encouraged to search ClinicalTrials.gov or consult their care team about eligibility.