Endobronchial Ultrasound is Useful in the Assessment of Bronchial Wall Changes Related to Bronchial Thermoplasty.

Background: Bronchial thermoplasty (BT) is an interventional endoscopic treatment for severe asthma leading to the clinical improvement, but morphologic changes of bronchial wall related to the procedure and predictors of a favorable response to BT remain uncertain. The aim of the study was to validate an endobronchial ultrasound (EBUS) in assessing the effectiveness of BT treatment. Methods: Patients with severe asthma who met the clinical criteria for BT were included. In all patients clinical data, ACT and AQLQ questionnaires, laboratory tests, pulmonary function tests and bronchoscopy with radial probe EBUS and bronchial biopsies were collected. BT was performed in patients with the thickest bronchial wall L2 layer representing ASM. These patients were evaluated before and after 12 months of follow-up. The relationship between baseline parameters and clinical response was explored. Results: Forty patients with severe asthma were enrolled to the study. All 11 patients qualified to BT successfully completed the 3 sessions of bronchoscopy. BT improved asthma control (P=0.006), quality of life (P=0.028) and decreased exacerbation rate (P=0.005). Eight of the 11 patients (72.7%) showed a clinically meaningful improvement. BT also led to a significant decrease in the thicknesses of bronchial wall layers in EBUS (L1 decreased from 0.183 to 0.173 mm, P=0.003; L2 from 0.207 to 0.185 mm, P = 0.003; and L3-5 from 0.969 to 0.886 mm, P=0.003). Median ASM mass decreased by 61.8% (P=0.002). However, there was no association between baseline patient characteristics and the magnitude of clinical improvement after BT. Conclusion: BT was associated with a significant decrease in the thickness of the bronchial wall layers measured by EBUS including L2 layer representing ASM and ASM mass reduction in bronchial biopsy. EBUS can assess bronchial structural changes related to BT; however, it did not predict the favorable clinical response to therapy.

Assessment of remodeling in chronic obstructive pulmonary disease using imaging methods.

INTRODUCTION: While spirometry plays a key role in diagnosing chronic obstructive pulmonary disease (COPD), imaging methods including endobronchial ultrasound (EBUS) and chest computed tomography (CT) appear to be useful for investigating structural changes in the lungs. OBJECTIVES: The aim of this study was to evaluate remodeling in COPD patients using EBUS and chest CT. PATIENTS AND METHODS: The study included 33 patients with COPD, 15 patients with severe asthma, and 15 control subjects. All subjects underwent pulmonary function tests and bronchoscopy with EBUS to measure the total thickness of the bronchial wall and its layers. Additionally, in COPD patients, a chest CT was performed to measure total bronchial wall thickness. RESULTS: The total bronchial wall thickness measured by EBUS in patients with COPD (1.192 ±0.079 mm) was significantly smaller than that in asthmatic patients (1.433 ±0.230 mm, P = 0.001) and significantly greater than in control subjects (1.099 ±0.095 mm, P = 0.04), and was positively correlated with residual volume (RV) / total lung capacity (r = 0.5, P = 0.02), RV (r = 0.6, P = 0.007), and RV (%) (r = 0.5, P = 0.05). The thickness of the bronchial wall layers in patients with COPD were as follows: L1 = 0.135 ±0.018 mm, L2 = 0.151 ±0.026 mm, and L3-5 = 0.906 ±0.065 mm. There was no correlation between the thickness of the bronchial wall layers and forced expiratory volume in 1 second. CONCLUSIONS: The results of this study show that EBUS is a useful method for evaluating bronchial wall layers not only in asthma but also in COPD, and suggest that the pattern of remodeling differs in each of these diseases.

The use of endobronchial ultrasonography in assessment of bronchial wall remodeling in patients with asthma.

BACKGROUND: Endobronchial ultrasound (EBUS) is a new technique that enables the assessment of bronchial wall layers. The aim of the study was to verify the utility of EBUS for the assessment of bronchial wall remodeling in patients with asthma. METHODS: In 35 patients with asthma and 23 control subjects, high-resolution CT (HRCT) scanning and EBUS were used to measure bronchial wall thickness in the 10th segment of the right lung. With a radial 20-MHz probe, EBUS identified the 5-laminar structure of the bronchial wall. Layer 1 (L(1)) and layer 2 (L(2)) were analyzed separately, and layers 3 through 5 (L(3-5)), which corresponded to cartilage, were analyzed jointly. Digitalized EBUS images were used for the quantitative assessment of bronchial wall thickness and the wall area (WA) of the layers. Finally, bronchial biopsy specimens were taken for measuring the thickness of the reticular basement membrane (RBM). The thickness and WA of the bronchial wall layers, which were assessed using EBUS, were correlated with FEV(1) and RBM. RESULTS: There was no significant difference in the measurements of total bronchial wall thickness using EBUS and HRCT scanning. The thickness and WA of the bronchial wall and its layers were significantly greater in patients with asthma than in the control subjects. A negative correlation among the thicknesses of L(1), L(2), and L(3-5) and FEV(1), and a positive correlation with RBM were observed only in the patients with asthma. CONCLUSIONS: EBUS allows precise measurement of the thickness and WA of bronchial wall layers. The correlation of these parameters with asthma severity suggests implementation of EBUS in the assessment of bronchial wall remodeling in patients with asthma.