Feasibility and Safety of Bronchoscopic Transparenchymal Nodule Access in Canines

Background The current approaches for tissue diagnosis of a solitary pulmonary nodule are transthoracic needle aspiration, guided bronchoscopy, or surgical resection. The choice of procedure is driven by patient and radiographic factors, risks, and benefits. We describe a new approach to the diagnosis of a solitary pulmonary nodule, namely bronchoscopic transparenchymal nodule access (BTPNA). Methods In anesthetized dogs, fiducial markers were placed and thoracic CT images acquired. From the CT scan, the BTPNA software provided automatic point-of-entry prescribing of a bronchoscopic path (tunnel) through parenchymal tissue directly to the lesion. The preplanned procedure was uploaded to a virtual bronchoscopic navigation system. Bronchoscopic access was performed through the tunnels created. Proximity of the distal end of the tunnel sheath to the target was measured, and safety was recorded. Results In four canines, 13 tunnels were created. The average length of the tunnels was 32.3 mm (range, 24.7-46.7 mm). The average proximity measure was 5.7 mm (range, 0.1-12.9 mm). The distance from the pleura to the nearest point within the target was 7.4 mm (range, 0.1-15 mm). Estimated blood loss was < 2 mL per case. There were no pneumothoraces. Conclusions We describe a new approach to accessing lesions in the lung parenchyma. BTPNA allows bronchoscopic creation of a direct path with a sheath placed in proximity to the target, creating the potential to deliver biopsy tools within a lesion to acquire tissue. The technology appears safe. Further experiments are needed to assess the diagnostic yield of this procedure in animals and, if promising, to assess this technology in humans.