Characterization of the upper pouch tracheo–oesophageal fistula in oesophageal atresia

Aim A small proportion of infants with oesophageal atresia (OA) are thought to have a proximal tracheoesophageal fistula (TOF). Failure to recognize these can hamper mobilization of the upper pouch and lead to life-threatening episodes of aspiration once oral feeding starts. We reviewed our experience of upper pouch fistulae to identify characteristic features of proximal TOF. Methods A retrospective review of TOF/OA patient notes and bronchoscopy photographs and videos, identified from our database from 01/01/2006 to 12/31/2015, was performed. Results Eight (6.1%) infants were identified (M:F 5:3) from a total population of 131 newly diagnosed TOF/OA infants during the period. Their median gestational age was 33 (range 28–39) weeks, and median birth weight was 1647g (range 1100–3400g). Five were initially diagnosed with pure OA and 3 with a distal TOF. All patients underwent rigid bronchoscopy at the initial surgery but only one proximal fistula was identified. The 7 missed proximal fistulae were subsequently found either during on-table oesophagograms for gap assessment (n=2), at the time of thoracotomy when mobilizing the upper pouch (n=3), or during subsequent bronchoscopy for symptoms post OA repair (n=2). Two patients needed a further operation to divide the fistula. Review of the bronchoscopy videos identified four characteristic differences between upper and lower pouch fistulae. Proximal fistulae are found just distal to the vocal cords, are very small, often no more than a pit, do not open and close with ventilation, and are best identified by insufflation of the esophagus. Conclusion Upper pouch fistulae are relatively easy to miss because of different characteristics compared with H-type or distal fistulae that have not previously been mentioned in the literature. Level of evidence: level IV.