Dear editor,

I was much interested in the recent article by Lai et al., by which they described a challenging case of right lung isolation because of a supernumerary tracheal bronchus.¹ Although they had provided valuable information, I would like to raise several concerns about right main bronchus (RMB) abnormalities, specifi cally in cases for thoracic procedures requiring right-sided one-lung isolation.

First, the distances from the bronchial cuff to the tracheal lumen orifi ce and the tracheal cuff were 3 cm and 4 cm, respectively, in the 37 French left-sided endobronchial tube (Mallinckrodt, Covidien, Mansfi eld, MA, USA). I believe that the obstructed supernumerary tracheal bronchus could be quickly relieved by merely withdrawing the tube 1 or 2 cm back if the aberrant bronchus originates only 2 cm above the carina. Under the bronchoscopic guidance, the proximal edge of the bronchial cuff should sit at the level of the carina. Deflation of the tracheal cuff is not reliable. Meanwhile, it may increase the risk of pulmonary aspiration. In their case, the tracheal cuff should be infl ated again once the operated lung collapsed adequately.

Second, abnormalities of the RMB, including short RMB (< 1 cm), carinal trifurcation and tracheal bronchus, are not uncommon and usually reported unexpectedly, even under fiberoptic bronchoscopic guidance of one-lung isolation.² However, for patients undergoing thoracic procedures, preoperative computed tomography can reveal most of the tracheobronchial abnormalities. Numerous cases reported in the literature had reminded us to look for tracheobronchial variations carefully before anticipated one-lung isolation. Most of the aberrant bronchi originate within 2 cm above the carina, and a left-sided double-lumen tube can easily separate the two lungs. For higher tracheal bronchus more than 2 cm, one should be aware that the tracheal bronchus may be occluded by the tracheal balloon of a double-lumen tube. In such cases, one-lung separation using endobronchial blockers are preferred but may need an extra blocker or a Fogarty embolectomy catheter inserted extraluminally to occlude the aberrant bronchus for right-sided procedures.

Third, an emerging trend of a nonintubated technique may be a perfect fit for these challenging patients by achieving one-lung isolation naturally, i.e., lung collapse after an iatrogenic open pneumothorax while the patients remain spontaneously breathing.^3,4 Nonetheless, an emergency airway management protocol should always be prepared in advance.

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