Anatomy of the right upper lobe revisited and clinical considerations in Chinese population

OBJECTIVE: The anatomy of the tracheobronchial tree differs among not only various races but also individual ethnic groups. Different lengths of the right mainstem bronchus (RMSB) had been described in previous publications. Since the differences in the anatomy of the RMSB and right upper lobe bronchus (RUB) may have clinical relevance when selecting devices, specifically, the right-side double lumen tube (R-DLT) for lung isolation, we revisited the anatomy of the right upper lobe in a large scale Chinese population. METHODS: In this retrospective cohort study, we reviewed 2093 consecutive adult patients undergoing thoracic computed tomography (CT) scans from data base in our hospital. Demographic characteristics were collected. The lengths, internal diameters, and angles of the RMSB and RUB were measured using reconstructive CT images. The correlations between the demographic variables and the RMSB length and diameters were also analyzed. RESULTS: The incidence of the aberrant RUB originated equal or above the tracheal carina was 8.1‰. 52.3% of the patients had a length of RMSB less than 23 mm, and the incidence of RMSB length <23 mm in women was significantly higher than that in men (63.5% vs. 42.8%, p = 0.000). The right bronchial length (RBL) was less than 10 mm in 21% of cases (17.8% in men and 24.8% in women, respectively, p = 0.000). Both the RMSB lengths and diameters had poor correlations with the heights in either male or female patients. CONCLUSION: A much higher incidence of a shortened RMSB potentially make placement of a R-DLT more difficult in Chinese population. Both the lengths and diameters of the RMSB cannot be predicted by the height. Preoperative thoracic CT scan for each patient helps optimizing the selection of a lung isolation device, and the importance of an evaluation of the CT scans preoperatively by the anesthesiologists should be emphasized.