Transbronchial cryobiopsy under simultaneous confocal laser endomicroscopy guidance for peripheral pulmonary lesions – a pilot study

Introduction Radial endobronchial ultrasound (rEBUS) guided transbronchial biopsy (TBB) is the most used technique for the diagnosis of peripheral pulmonary lesions. However, the TBB cannot be performed under simultaneous ultrasound guidance as the rEBUS probe has to be removed prior to the biopsy. To provide an endobronchial imaging-based guided TBB, the safety and feasibility of cryobiopsy under simultaneous probe-based confocal laser endomicroscopy (pCLE) control is analyzed for the first time in this prospective pilot study. Methods Fifteen patients with a pulmonary lesion suspicious for malignancy were enrolled in this prospective pilot trial from September 2023 to December 2024 at the Division of Pulmonology, Department of Internal Medicine II, Medical University of Vienna, Austria. After identifying the lesion by the rEBUS, a cryoprobe and an AQ FlexTM probe were inserted simultaneously under fluoroscopic guidance. Based on the pCLE images, the position of the cryoprobe was optimized and TBB were performed. The safety and feasibility were evaluated. Results In 11 patients in whom the pulmonary lesions were identified by rEBUS, a transbronchial cryobiopsy could be performed under simultaneous pCLE guidance without any complications. The cryoprobe and the AQ FlexTM probe could be inserted easily in parallel into the lesion in all casesOverall, the agreement between the “tool-in-lesion” signal based on CLE images and the proof of malignancy was found to be 82%. Conclusion A transbronchial cryobiopsy under simultaneous pCLE guidance using an AQ FlexTM probe for peripheral pulmonary lesions is feasible and safe. Further studies are needed to evaluate the additional benefit of CLE imaging.