Investigating congenital isolated tracheo-oesophageal fistula: considering CT scan?

A 4-year-old boy was referred with recurrent pneumonia and aspiration of liquids. Clinical examination, complete blood count and sweat test were normal. A tracheo-oesophageal fistula (TEF) was suspected as a differential diagnosis. Barium swallow was unremarkable. Tracheoscopy showed a small mucous irregularity on the posterior wall, but intra-oesophageal instillation of methylene blue was not perceived in the trachea. Tracheoscopy was interrupted prematurely due to poor respiratory tolerance. Finally, chest CT scan showed a millimetre-wide TEF originating from the trachea …