Use of nasopharyngeal airway for interim dilatation of lower tracheal stenosis.

Sir,

A 14-year-old boy, with tracheal stenosis, was scheduled for endoscopic assessment under anesthesia. History includes head injury with craniotomy, and tracheostomy was performed postoperatively. Previous bronchoscopic assessment revealed a 3 cm tracheal stenosis segment 1 cm above carina, the tracheostomy tube (TT) was replaced with a 5.0 mm ID cuffed endotracheal tube (ETT) bypassing the stenosis through the tracheal stoma. The patient subsequently underwent multiple bronchoscopic assessment and finally Vygone extra length 6.0 mm TT secured after confirmed bilateral air entry. Again the patient developed respiratory distress; the TT was replaced with a 6.0 mm ID cuffed ETT and posted for further bronchoscopy.

We connected the routine monitors to the patient. Anesthesia was induced with oxygen; sevoflurane, breathing spontaneously through the ETT and adequacy of ventilation was checked. Fentanyl and atracurium were given to facilitate rigid bronchoscopic examination; supra-glottic, glottic, and subglottic airway revealed no abnormality. ETT was removed to allow assessment of lower airway; ventilation was achieved through ventilating bronchoscope. Endoscopic findings revealed a circumferential stenosed segment starting 2.2 cm above the carina measuring 3 cm in length. It was observed that bronchoscope (size 10.0 mm) could be passed beyond the stenosed segment, meaning it was a dilatable stenosis and ventilation was easy without any audible air leak. It was also observed that the stenotic segment was collapsing while removing the bronchoscope. As the patient had undergone multiple bronchoscopic assessments (six times) under general anesthesia without any definite management, we thought of nasopharyngeal airway (NPA) and no. 7.5 mm (OD, 10.0 mm) sterile NPA was inserted as a stent through the tracheal stoma, which was easily placed and bypassing of the stenotic segment was confirmed endoscopically. The unobstructed ventilation and bilateral air entry were checked, and NPA was secured in place [Figure 1]. In the postoperative period, the NPA was changed to the higher size after every 3 days till we could pass the no. 8.5 mm NPA without any resistance. After this, it was replaced with a 12.0 mm size of montgomery silicon T-tube (MT).

Figure 1

(a) Nasopharyngeal airway placed through the tracheal stoma, bypassing of the stenotic segment in OT. (b) A patient in a ward with nasopharyngeal airway as an interim tracheal stent

Tracheal stenosis is the most common late airway complication of prolonged intubation and/or tracheostomy.[1] The therapeutic options include: Tracheal resection and reconstruction, laser reconstruction, electrocautery excision of the tissue, tracheal dilatation, and stenting.

In these cases of tracheal stenosis where the TT/extra length TT are not sufficient to bypass the stenosis segment, the MT is required. It becomes a very costly affair as we start first with a small tube and gradually increase the tube size to achieve adequate tracheal lumen. So the patient buys a new MT every time thereby increasing the expenditure. In our case, we used the gradually increasing sizes of NPA which was less costly as compared to the MT. NPA is a simple, non-collapsible, sterile, easily available, and cheaper airway adjunct; primarily used for securing airway in emergency situations.[2] We suggest that NPA can be used as an interim tracheal stent in lower tracheal stenosis where TT/extra length TT is not sufficient to bypass the stenotic segment, like in our case.