Discussion
The main goals of EA/TEF management are timely recognition of underlying malformation and reduction of associated complications. To our knowledge this is the first study concerning preoperative management of neonates with EA/TEF and moderate respiratory distress; where we utilized the novel FE-NIV-SPI approach to make accurate diagnosis, insert NTFG tube and subsequent management to stabilize condition before surgical intervention.
Shunting of ventilation through the fistula presents a major challenge in managing neonates of EA/TEF with respiratory distress requiring PPV support. Placing the ETT tip distal to the fistula is the principle key to minimize ventilation loss through fistula. However, majority of the TEFs reported are located within 1.0 cm from carina or even at the level of carina, making this distal placement of ETT difficult.17 Routine preoperative endoscopy in neonates with EA/TEF remains inconsistent, but several studies highlighted its usefulness in locating the fistula and associated airway anomalies for deciding operating approach.6,7,18–21Previous literatures described using Fogarty catheter6or a semi-rigid umbilical catheter7 either to directly balloon-occlude the fistula or prevent gastric distention, respectively, for improving lung ventilation. This case series demonstrated that the FE-NIV offered a practical and effective benefits in both pre- and post-operative clinical management.
This FE-NIV-SPI technique provides several advantages especially in high-risk neonates. 1) In our previous study11 of same setting, the SPI with duration of 0 to 5 seconds could create well correlated positive pressure levels of 4.1±3.3 to 65.5±18.5 cmH2O in laryngopharyngeal space. This transient, dynamic and controllable positive pressure is safe and enough to expand the collapsed aeroesophageal lumens in case of EA/TEF. 2) Oxygen insufflation through the nasopharyngeal catheter can directly flush upper airway dead space, as the effects of “apneic oxygenation”,22-26 which may significantly prolong onset of desaturation. 3) Both assist inspiration and expiration can be optionally achieved by this simple maneuver to provide enough oxygenation and ventilation. 4) No instruments such as mask, ETT, ventilation bag or mechanical ventilator are needed, hence eliminate preparation time and provide an unobstructed and unimpeded viewing field for FE assessment and manipulation. 5) With improved PPV and visual field, that facilitates accurate FE assessment of aeroesophageal tracks such as length of TM, orifice diameter of TEF, distance between TEF and carina, depth of the blind esophageal pouch; and consequent interventions such as precise insertion of NTFG tube, ETT intubation, laser and balloon measurement and even stent implantation in these compromised neonates.
The NTFG tube placement has the following advantages. 1) Early occlusion of the fistula prevents PPV loss that eliminate distension of stomach or intestine, as the Case 1 with duodenal atresia (DA), and allows for gastric feeding. 2) It facilitates effective lung ventilation, even in neonates who require ETT PPV. 3) It offers stabilizing option that can avert the need for emergent gastrostomy. 4) It preserves intact peritoneal cavity and provides future benefits for intra-abdomen procedures. 5) During surgical repair of EA/TEF, NTFG tube decompression declines risk of surgical field contamination by gastric contents. 6) NTFG tube can also act as a guide for locating the fistula during operation. For patients similar to Case 1, staged repair consisting of gastrostomy and fistula ligation followed by DA repair one week later had been reported.27 This approach could allow for a less hurried and well-prepared simultaneous surgical correction of both EA/TEF and DA lesions in one session. Nevertheless, cannulation of NTFG tube or concurrent ETT intubation require skillful technique of FE-NIV, especially when performed in small neonates with multiple comorbidities. Further large studies are required for validation and widespread application.