Background Subglottic cysts (SGCs) are a rare, but important cause of stridor in children. They can cause significant upper airway obstruction, with potentially lethal consequences, particularly when exacerbated by upper respiratory tract infection. Although seen typically in pre-term infants, there is a paucity of literature regarding their aetiology.

Aim To examine the background characteristics and to determine any risk factors in paediatric patients with SGCs.

Methods A retrospective case control study was conducted, reviewing reports of all laryngotracheobronchoscopies (LTB) conducted in a tertiary paediatric hospital, between January 2009 and 2014. SGCs were identified in 15 patients from the 1095 LTBs performed. Cases were matched to controls based on gestational age at birth, birth weight and age. Medical records of cases and controls were reviewed to identify possible risk factors.

Results Of the 15 patients with SGCs, 14 were born prematurely. All of the patients with SGCs had been ventilated, and 13 of the 15 controls were ventilated. Overall time of ventilation and frequency of re-intubations were similar between the two groups, however SGCs patients had significantly higher frequency of ETT suctioning conducted during period of ventilation.

Conclusion This study demonstrated an association of SGCs in the pre-term infants with previous intubation. SGCs were more prevalent in infants that required more frequent suctioning. Consequently it is likely that infants with repeated or multiple manipulations of the airway may be at higher risk for developing SGCs and should be followed up closely to avoid potential life threatening complications.