Hagihira et al.  1reported the usefulness of a new double-lumen endobronchial tube specially designed for patients with a short right mainstem bronchus. Using x-ray data, they outlined that Japanese patients have, on average, a shorter right mainstem bronchus than American patients. We would caution against such x-ray measurements because of the spatial orientation of the main bronchi. This is particularly important when the left mainstem bronchus diameter is measured to choose an appropriate double-lumen tube. As the left mainstem bronchus is oblique through the horizontal plane, it is necessary to perform a multiplane reconstruction of the tracheobronchial tree using transverse, sagittal, and coronal tomodensitometric slices to obtain a strictly orthogonal slice of the left mainstem bronchus.2Such precautions are mandatory to prevent mismeasurement.

*Hôpital Foch, Suresnes, France. m.fischler@hopital-foch.org

1.
Hagihira S, Takashina M, Mashimo T: Application of a newly designed right-sided, double-lumen endobronchial tube in patients with a very short right mainstem bronchus. Anesthesiology 2008; 109:565–8
2.
Olivier P, Hayon-Sonsino D, Convard JP, Laloë PA, Fischler M: Measurement of left mainstem bronchus using multiplane CT reconstructions and relationship between patient characteristics or tracheal diameters and left bronchial diameters. Chest 2006; 130:101–7