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

Abstract

Jerzy Soja,1,2 Karolina Górka,1,2 Iwona Gross-Sondej,1,2 Bogdan Jakieła,2 Sławomir Mikrut,3 Krzysztof Okoń,4 Adam Ćmiel,5 Piotr Sadowski,4 Wojciech Szczeklik,6 Anna Andrychiewicz,7 Tomasz Stachura,1,2 Grażyna Bochenek,1,2 Stanisława Bazan-Socha,2 Krzysztof Sładek1,2 1Department of Pulmonology and Allergology, University Hospital, Kraków, Poland; 2 2nd Department of Internal Medicine, Jagiellonian University Medical College, Kraków, Poland; 3Faculty of Mining, Surveying and Environmental Engineering, AGH University of Science and Technology, Kraków, Poland; 4Department of Pathology, Jagiellonian University Medical College, Kraków, Poland; 5Department of Applied Mathematics, AGH University of Science and Technology, Kraków, Poland; 6Centre for Intensive Care and Perioperative Medicine, Jagiellonian University Medical College, Kraków, Poland; 7Department of Endoscopy, University Hospital, Kraków, PolandCorrespondence: Jerzy Soja, Department of Internal Medicine, Faculty of Medicine, Jagiellonian University Medical College, Jakubowskiego 2, Krakow, 30-688, Poland, Email [email protected]: 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.Keywords: airway remodeling, airway smooth muscle, bronchial thermoplasty, bronchial wall layers, endobronchial ultrasound

Keywords

• airway remodeling
• airway smooth muscle
• bronchial thermoplasty
• bronchial wall layers
• endobronchial ultrasound