Flexible bronchoscopy-guided placement of self-expandable metallic stent for central airway obstruction-should preferably be the path less travelled!

Abstract

To the Editors: We congratulate the authors of the article, ‘Airway stenting: technological advancements and its role in interventional pulmonology’, published in Respirology in March 2020 for their very well-written review.1 Guibert et al. have presented in detail on the available airway stents, indications for airway stenting and the role of both flexible and rigid bronchoscopy in its deployment. We agree with the authors on the limited role for flexible bronchoscopy in placement of self-expandable metallic stent (SEMS), and that rigid bronchoscopy-guided placement of SEMS should be the recommended option. However, we propose that attributing the growing popularity of SEMS to the absence of skills in rigid bronchoscopy, although true, is quite worrisome. In our view, it is essential that bronchoscopists who perform airway stenting acquire skills for performing rigid bronchoscopy before attempting airway stenting with flexible bronchoscopy. Why so? Apart from offering quick control of obstruction and haemorrhagic complications (as stated by the authors), rigid bronchoscopy-guided SEMS placement has advantages of avoiding unanticipated procedural complications. In our centre, we have on occasions considered some airway stenting cases to be straight forward, and have proceeded with flexible bronchoscopy, only to be met by potentially avoidable challenges. We have faced acute respiratory decompensation when a critical airway became even ‘more critical’ with failure of expansion of the deployed stent (Fig. 1A,B). We have had miscalculated deployment of covered straight metallic stents, with the stent proximally covering vocal cords or distal stent deploying into the right main bronchus with subsequent closure of the left main bronchus lumen. Both were further complicated by the concealment of the proximal thread of the stent between the stent and underlying vocal cord or tracheal wall, making it a technical challenge to remove the stent (Fig. 1C,D). On one occasion, a covered straight metallic stent on deployment migrated through the right main bronchus into the proximal intermedius bronchus, leading to closure of both the left main and right upper lobe bronchi. Adding to our woes, the proximal thread of the stent was trapped in between the stent and underlying tracheal wall. After multiple failed attempts to catch the proximal edge of the stent with a flexible biopsy forceps, our patient developed acute vocal cord oedema and respiratory distress. As our backup rigid bronchoscopy was being swung into action, we were watching the peripheral oxygen saturation crash and realized we did not have much time. Thus, we caught the distal end of the stent in the intermedius bronchus with flexible biopsy forceps, and pulled it up through the lumen of the stent through the right main bronchus and trachea, in the process turning the stent inside out (Fig. 1E–H). These complications could have been avoided if these procedures were performed with rigid bronchoscopy. Hence, we insist that airway stenting should be performed under rigid bronchoscopy, and if performed under flexible bronchoscopy, rigid bronchoscopy should be available for any backup that may be necessary.