Subglottic cysts in the premature infant.

Supraglottic cysts in the newborn are a well-recognized entity, but subglottic cysts have been rarely reported. Over the past 6 years we have observed subglottic cysts in nine patients with relatively long intubations from the neonatal intensive care unit of two university hospitals. Most frequently the patients were extubated and did well for weeks or months, but then they had progressive biphasic stridor. On endoscopy the patients had a subglottic stenosis that was irregular but with a smooth mucosal lining. Usually the cysts were apparent, but in two patients the mucosa was thickened and the patients were treated as a subglottic stenosis with tracheostomy. These subglottic cysts were recognized at the time of laryngotracheoplasty. In six patients the cysts were managed either by marsupialization with cup forceps, endoscopic diathermy, or carbon dioxide laser without recurrence. It is our belief that this condition is most likely due to scarring and obstruction of mucus glands of the subglottic area from prolonged intubation. This entity should be recognized and looked for in the neonate who has an acquired subglottic stenosis and should first be treated conservatively with endoscopic marsupialization.