In the present case, the patient presented with esophageal atresia type C concurrently with duodenal atresia. In such case, the gas delivered into the stomach via a TEF lacks an outlet due to the simultaneous obstruction of the duodenum and the esophagus. Consequently, the risk of gastric distension and rupture increases significantly [13,14,15]. This necessitates a heightened level of vigilance in airway and respiratory management. Therefore, considering the patient was scheduled for ongoing ventilatory management in the NICU post-gastrostomy and was also slated for corrective surgery for TEF, we believed it was beneficial to estimate the TEF location after the gastrostomy through the approaches presented.

The location of the TEF was verified at the level of the junction between the superior vena cava and the azygos vein during the corrective surgery for TEF, indicating that our estimation methods were efficacious [16]. A prior study has indicated that in approximately 88% of esophageal atresia cases, a TEF was located above the tracheal bifurcation [17]. On the other hand, in 12% of cases, a TEF was situated below the tracheal bifurcation, exclusively in the right main bronchus, with no instances reported in the left main bronchus [17]. Given the high probability of a TEF being present in the right main bronchus when situated below the tracheal bifurcation, it becomes possible to approximate the TEF location by advancing a tracheal tube.

In addition to the methods described in this report, both fiber-optic and rigid bronchoscopes can be applicable [18, 19]. However, the use of a fiber-optic bronchoscope is precluded when the inner diameter of the tracheal tube is narrow, as demonstrated in this case. Furthermore, a rigid bronchoscopy, ideally conducted under general anesthesia with preserved spontaneous respiration, is not feasible in facilities lacking a rigid pediatric bronchoscope. While our method requires a pre-established gastrostomy, it offers a practical alternative for locating a TEF when equipment for narrow-diameter fiber-optic or rigid bronchoscopy is unavailable.

In the current case, a 2.5-mm inner diameter tracheal tube was utilized. Consequently, locating the TEF via a fiber-optic bronchoscope was not feasible at our facility, which lacked a readily available fiber-optic bronchoscope with an outer diameter of 2.2 mm. Although we could have used a 2.5-mm fiber-optic bronchoscope by switching to a 3.0-mm inner diameter tracheal tube, we chose not to switch, as the 2.5-mm tube provided adequate positive pressure ventilation with a manageable air leak.

We recognize several limitations of the methods. Firstly, the practice of blindly advancing a tracheal tube may precipitate complications such as gastric distention and rupture resulting from positive pressure ventilation. However, as evidenced in the present case, the gastrostomy tube facilitated the evacuation of intragastric gas, enabling the prevention of severe complications. Secondly, if the tracheal tube inadvertently strays into a TEF, air bubbles may continuously emanate from the gastrostomy tube. Under such circumstances, the misplacement would be detected through a reduction in the end-tidal carbon dioxide concentration. Thirdly, if a TEF is in the right main bronchus and the tracheal tube is advanced to the left main bronchus, no air bubbles would emerge from the gastrostomy tube, potentially leading to misidentification of the TEF location. Thus, if air bubbles cease after left main bronchus intubation, intubation of right main bronchus may be needed to locate the TEF.

Based on the foregoing considerations, we advocate for the technique of blindly advancing a tracheal tube and estimating the location of a TEF by observing gas outflow from a gastrostomy tube submerged in water, synchronized with positive pressure ventilation. This estimation strategy would enable the identification of a TEF location without the need for a thin fiber-optic bronchoscope. Although this method should be performed with a high degree of caution by anesthesiologists, this technique would be especially useful in environments where medical resources are limited. Further investigation into this technique is warranted.