A new technique combining virtual simulation and methylene blue staining for the localization of small peripheral pulmonary lesions

Background: Quickly and accurately localizing small peripheral pulmonary lesions can avoid prolonged operative time and unplanned open thoracotomy. In this study, we aimed to introduce and evaluate a new technique combining virtual simulation and methylene blue staining for the localization of small peripheral pulmonary lesions. Methods: Seventy four (74) patients with 80 peripheral pulmonary lesions <20 mm in size on computer tomography (CT) were virtually punctured using a radiotherapy planning simulator on the day before operation. Under general anaesthesia, methylene blue dye was injected to the virtually identified point according to the surface point, angle and depth previously determined by the simulator. The wedge resection of the marked lesion was performed under video-assisted thoracoscopic surgery (VATS) and the specimens were sent for immediate pathologic examination. According to pathology results, appropriate surgical procedures were decided and undertaken. Results: The average lesion size was 10.4 +/- 3.5 mm (range: 4-17 mm) and the average distance to the pleural surface was 9.4 +/- 4.9 mm. Our preoperative localization procedure was successful in 75 of 80 (94%) lesions. Histological examination showed 28 benign lesions and 52 lung cancers. The shortest distance between the edges of the stain and lesion was 5.1 +/- 3.1 mm. Localization time was 17.4 +/- 2.3 min. All patients with malignant lesions subsequently underwent lobectomy and systematic lymph node dissection. No complications were observed in all participants. Conclusions: The novel technique combining the preoperative virtual simulation and methylene blue staining techniques has a high success rate for localizing small peripheral pulmonary lesions, particularly for those tiny lesions which are difficult to visualise and palpate during VATS.