Transbronchial Access of Solitary Pulmonary Nodules Without Bronchus Sign Using a Novel Puncture Dilatation Catheter: Initial Feasibility Experience.

Radial endobronchial ultrasound (rEBUS) guided biopsy is highly effective for solitary pulmonary nodules exhibiting a bronchus sign. While ancillary techniques like cryobiopsy improve yields for lesions adjacent to the airway, nodules situated deeper within the lung parenchyma or behind stenotic, fibrotic airways often require specialised transbronchial access. Conventional transbronchial access tools are frequently limited by their large calibre, requiring bronchoscopes with wide working channels and complex, multi-step deployment that increases procedural complexity. We report our initial clinical experience with a novel, single-use transbronchial puncture dilatation catheter. This device features a flexible sheath with a tapered distal end and an integrated needle stylet, specifically designed to simplify bronchial wall penetration and parenchymal tunnelling via a thin bronchoscope with 2.0 mm working channel. We present two cases: a solitary pulmonary nodule lacking a bronchus sign and a second case involving a fibrotic, stenotic airway that precluded standard rEBUS probe insertion. In both instances, the novel catheter facilitated successful 'off-road' navigation, allowing for rEBUS verification and definitive sampling with cryoprobe and forceps. Both procedures were technically successful, yielding metastatic adenocarcinoma and caseating granulomatous inflammation, respectively. This case series explores the early clinical utility of this simplified transbronchial access tool and discusses its current limitations.