Between January, 2013 and September, 2014, RP-EBUS-guided SPN localization with an ultrathin bronchoscope and methylene blue, followed by VATS, was conducted on 48 SPNs from 48 patients who underwent CT examination at the Nanjing Clinical Center of Respiratory Diseases and Imaging (Nanjing, China). The study included 18 men and 30 women, with a mean age of 54 years (range, 41–72 years). Of the 48 patients, 12 had a cancer history. The patient characteristics are summarized in Table I. The study protocol was approved by the Ethics Committee of the Nanjing Chest Hospital and all the patients provided written informed consent.

Each patient had been diagnosed with a pulmonary nodule on a CT scan of the chest, measuring 10 mm (Fig. 1). RP-EBUS scanning was conducted under anesthesia, with percutaneous blood oxygen saturation monitoring and continuous electrocardiography during the examination process. A 2.0-mm, 20-MHz radial mechanical transducer type endobronchial ultrasonic probe (UM-BS20-26R; Olympus, Tokyo, Japan) with a flexible balloon sheath (MAJ-643R; Olympus) was introduced through the 2.8-mm channel of a flexible bronchoscope (XBF-22L; Olympus). The probe was connected to the endobronchial ultrasonography unit (EU-M 20/30; Olympus). The visible bronchial segment was examined until the characteristic ultrasound signal indicating the presence of a solid lesion (Fig. 2). The EBUS probe was removed and 0.3 ml methylene blue was injected at the marked point, according to the angle and depth data.

Thoracoscopic segmentectomy was performed under general anesthesia using single-lung ventilation. The technique utilized three incisions. The observation port was ~1 cm in length at the midaxillary line in the 6th or 7th intercostal space. The main operation port was placed in the 3rd or 4th intercostal space at the anterior axillary line. The accessory operation port was usually placed at the posterior axillary line in the 6th intercostal space. Both operation ports were ~2 cm in length.

The methylene blue was visualized during the exploration and the location of the lesion was confirmed (Fig. 3). The initial step was dissection of the hilar lymph nodes to ensure safe sublobar resection. The lymph nodes were sent for frozen section analysis and sublobar resection was abandoned if positive nodes were identified.

The approach to thoracoscopic segmentectomy begun with ligation of the segmental pulmonary vein and artery using thoracoscopic linear mechanical staplers. The bronchus was further isolated and dissected by stapler. Subsequently, the ipsilateral lung was temporarily reinflated to help identify the segmental fissures. After the fissures were marked with electrocautery and squeezed by long kelly clamps, the segmental plane was finished with an endostapler. In certain cases, we had to convert to a thoracotomy due to problems such as adhesions or failure of localization.

In 35 (72.9%) of the 48 patients, the methylene blue was visualized in or adjacent to the pulmonary nodule as documented following VATS resection (Fig. 4). The maximal diameter of the SPNs, their distance from the pleural surface and their histological diagnosis are summarized in Tables II and III. The diameter of the nodules ± standard deviation (SD) was 12.8±4.2 mm and located at a distance of 11.2±9.7 mm from the pleural surface. A total of 35 nodules were malignant and 13 were benign. A total of 12 lesions were located in the right upper lobe, 10 were in the right lower lobe, 16 in the left upper lobe and 10 in the left lower lobe.

The duration of localization, measured from the administration of local anesthesia, ranged between 10 and 28 min (mean, 15 min) and the number of ultrafine bronchoscope insertions or adjustments ranged between 3 and 6 (mean, 3). The only complication of RP-EBUS-guided localization with the combination of an ultrafine bronchoscope and methylene blue was asymptomatic hemorrhage, which was observed in 8.3% of the patients. VATS was performed in all 48 patients; 38 cases underwent wedge resection, including 13 benign and 25 malignant lesions and the remaining 8 patients underwent lobectomy and lymphadenectomy. The mean surgery duration ± SD for wedge resection and lobectomy was 25±8 and 90±30 min, respectively.

In two cases the procedure was converted to thoracotomy: One SPN strongly adhered to the pleural surface and the other was difficult to localize. The characteristics of the RP-EBUS-guided localization with an ultrafine bronchoscope and methylene blue and subsequent VATS are summarized in Table IV.