Advances in techniques for identifying small pulmonary nodules.

Since the introduction of video-assisted thoracoscopic surgery, the demand for its use in resecting small pulmonary nodules has increased. In parallel, the development of high-resolution computed tomography has led to an increase in the detection of the early lung cancers appearing as nodules with ground-glass opacity. Several techniques to resect these small lesions have been devised, the most familiar of which is the use of a computed tomography-guided percutaneous hook wire. We recently developed virtual-assisted lung mapping to achieve safer and more reliable resection of these lesions. Virtual-assisted lung mapping is carried out using three-dimensional computed tomography, bronchoscopy, and fluoroscopically guided navigation to mark the lung surface with dye. A prospective study showed that this technique was safe and had a high success rate. Multiple marking around the targeted lesion allows for a sufficient surgical margin at resection. We recently introduced an electromagnetic navigation bronchoscopy system to confirm the sites to be marked by virtual-assisted lung mapping in the operating room prior to video-assisted thoracoscopic surgery. We are now studying a method to enable minimally invasive, safe, and reliable resection of lesions located deep in the lung parenchyma.