Low flow intermittent bronchoscopic oxygen insufflation to identify occult tracheo-esophageal fistulas

Background: Esophageal atresia and tracheo-esophageal fistula (TEF), a well described congenital anomaly of the aero-digestive tract, commonly presents with inability to swallow and feed immediately after birth. However, diagnosis of recurrent or isolated TEF can be challenging and requires a combination of endoscopic and contrast studies. We describe a hitherto unreported technique of low flow intermittent oxygen insufflation into the suspicious tract and examine its safety and diagnostic yield for identification of occult TEF. Methods: A retrospective single center cohort study, analyzing case notes of patients with TEF who underwent bronchoscopic oxygen insufflation for suspected recurrent or isolated TEF between 2006 and 2019 at a tertiary pediatric hospital. Results: One-hundred and seven patients with TEF underwent 142 bronchoscopies during the study period. Of these, 22 patients underwent 28 bronchoscopies with oxygen insufflation. Twelve (43%) open fistulas were identified; of these, 9 (75%) were found using oxygen insufflation, revealing the fistula in 4/9 (44%) cases that had not been apparent using simple bronchoscopic visualization alone. One fistula was missed with multiple investigations, including bronchography and found only using oxygen insufflation. No complications were encountered. Conclusions: Recurrent or isolated TEF may be missed using ordinary flexible bronchoscopy and imaging studies. Low flow oxygen insufflation can be applied safely and may detect otherwise occult TEF.