BAL Contribution to Lung Cryo-TBB in ILD

The c-TBB procedure was performed under general anesthesia with rigid bronchoscopy guidance. The biopsy site was selected based on the area of highest involvement seen on thoracic CT. After evaluating the trachea and main bronchi with a rigid bronchoscope, a flexible bronchoscope was advanced into the target segment. Using a 1.9 mm, 90 cm cryoprobe, tissue was frozen and rapidly retracted with the bronchoscope to obtain the biopsy. The specimen was placed in formalin without damage. Hemorrhage control was achieved with a Fogarty balloon. A chest X-ray was taken two hours later to check for pneumothorax risk.

The BAL protocol, including pre-procedural preparations and the procedure itself, was performed in accordance with the American Thoracic Society (ATS) guidelines. In cases of diffuse involvement, BAL was performed from the middle lobe or lingula, while in localized involvement, it was done from the affected area. The target segment was occluded with the bronchoscope, and room-temperature 0.9% NaCl solution was instilled in 20 cc portions and gently aspirated to prevent airway collapse. A minimum of 100 mL (maximum 300 mL) saline was used, with at least 30% recovery required. Cellular analysis of BAL fluid was conducted per ATS guidelines. Normal cell distribution: alveolar macrophages \>85%, lymphocytes 10-15%, neutrophils ≤3%, eosinophils ≤1%, squamous/ciliated columnar epithelial cells ≤1%.