Advanced bronchoscopy for the diagnosis of peripheral pulmonary lesions

Bronchoscopy to examine peripheral pulmonary lesions is performed using a bronchoscope with an outer diameter of 5-6mm under fluoroscopy, but the diagnostic yield can be insufficient. Problems with transbronchial biopsy include a limited range of bronchoscope insertion, difficulty in guiding a bronchoscope and biopsy instruments to lesions, and insufficient confirmation of the arrival of biopsy instruments at the target lesion; as such, new techniques have been used to overcome these individual problems. Radial-endobronchial ultrasound is used to identify peripheral pulmonary lesions and sampling sites. In a meta-analysis, the diagnostic yield, that of lesions smaller than 2cm, and complication rate were 73, 56.3, and 1.0%, respectively. Virtual bronchoscopic navigation is a method to guide a bronchoscope to peripheral lesions under direct vision using virtual bronchoscopic images of the bronchial route, and the diagnostic yield, that of 2-cm or smaller lesions, and complication rate were 73.8, 67.4, and 1.0%, respectively. Electromagnetic navigation utilizes electromagnetism; the diagnostic yield was 64.9-71%, and the pneumothorax complication rate was 4% for this modality. Ultrathin bronchoscopes can be advanced to the peripheral bronchus under direct vision in contrast to normal-size bronchoscopes, and the diagnostic yield and pneumothorax complication rates were reported to be 63 and 1.5%, respectively. The overall diagnostic yield of these new techniques on meta-analysis was 70%, a higher yield than that obtained with conventional transbronchial biopsy. Each technique has advantages and disadvantages, and the investigation of appropriate combinations corresponding to individual cases is necessary.