Development of congenital laryngeal atresias and clefts

Congenital supraglottic laryngeal obstruction still is being described as subglottic stenosis. There are three clearly defined types of congenital laryngeal atresia, which result from arrest at consecutive developmental stages. Type 1 consists of a supraglottic obstruction, absent vestibule, and stenotic infraglottis, and type 2 is a supraglottic obstruction that separates a shallow primitive vestibule above from a nonstenotic infraglottis. These two types usually are accompanied by other defects, many of them severe. In type 3, a perforated membrane partly obstructs the glottis. Arrest of the dorsal advance of the chondrifying cricoid before the ends meet to form the dorsal lamina results in a complete laryngeal cleft, and incomplete fusion of the ends may leave a notch and/or foramen within the lamina. Failure of the interarytenoid tissue to develop will produce a local cleft, and maldevelopment of the cricoid cartilage or infraglottic submucosa can result in true subglottic stenosis without supraglottic obstruction.