# Comprehensive Tracheobronchial Morphometry in Korean Adults: Clinical Implications for Double-Lumen Tube Sizing and Right Upper Lobe Alignment

## TL;DR

This study provides detailed measurements of airway structures in Korean adults to improve the accuracy of double-lumen tube placement during surgery.

## Contribution

The study presents population-specific tracheobronchial morphometric data for Korean adults using 2D and 3D CT.

## Key findings

- Bronchial dimensions are larger in men, but height correlates more strongly with bronchial diameter in women.
- 2D CT tends to overestimate bronchial transverse diameters compared to 3D CT.
- RUL orifice deviation is greater in men than in women, with weak predictive value from height and weight.

## Abstract

Background/Objectives: Accurate knowledge of tracheobronchial anatomy is essential for safe airway management, particularly during one-lung ventilation using double-lumen tubes (DLTs). However, population-specific morphometric data in Asian adults remain limited. We aimed to establish a comprehensive morphometric profile of the tracheobronchial tree in Korean adults using 2D and 3D computed tomography (CT), and evaluate the clinical implications for DLT sizing and right upper lobe (RUL) alignment. Methods: This retrospective observational study included 398 adults who underwent preoperative chest CT. Measurements included tracheal dimensions, bronchial lengths, bronchial diameters, and anteroposterior angle of the RUL orifice. Height tertiles and sex-stratified linear regression analyses were performed to evaluate height–bronchial diameter relationships. Results: Bronchial dimensions were larger in men; however, height was more closely related to bronchial diameter in women. In women, each 1 cm increase in height corresponded to a 0.071 mm increase in left and a 0.077 mm increase in right bronchial transverse diameter (p < 0.001 for both). The RUL orifice showed posterior deviation of 15.5 ± 12.2° in men and 9.9 ± 11.4° in women, with height and weight being independent but weak predictors (R2 = 0.05). Bronchial diameter measurements showed consistent differences between 2D and 3D CT, with 2D images generally overestimating transverse diameters. Conclusions: The present analysis provides population-specific reference values for Korean adults. Our findings support the use of 2D CT as a practical tool for estimating bronchial dimensions and guiding DLT selection, and may serve as foundation for future airway devices tailored to Asian populations.