[Anatomy for the bronchologist: a prospective study of the normal endobronchial anatomic variants].

A comprehensive knowledge of the normal pattern of endobronchial branching is essential to any pulmonologist. The classification systems available are predominantly static descriptions and only seldom do they refer to possible variations within the normal spectrum. To evaluate all possible anatomical variants of the tracheobronchial tree we conducted a prospective study in our endoscopy unit between February, 1st and July, 10th (2009). A total of 181 individuals were included in the study. Anatomical variants were found to be present in 79 individuals (43% of total). Overall we found 20 different anatomical variants. Variations were more frequently found within the right upper lobe (16.6% of individuals). Middle lobe and lingula presented no variations. The variant most frequently found was the presence of a bifurcate pattern of the right upper bronchus (13.8%). The present study revealed a relatively high frequency of anatomical alternatives to the normal endobronchial branching pattern. Recognition of these variants and the frequency of their expression are fundamental for the bronchologist in establishing the limits of normal anatomy and preparing endobronchial techniques or surgical procedures.