Intraoperative electromagnetic navigational bronchoscopic localization of small, deep, or subsolid pulmonary nodules

Background: Localizing small or deep pulmonary nodules or subsolid groundglass opacities often is difficult during video-assisted thoracoscopic surgery (VATS) or robotic-assisted thoracoscopic surgery (RATS). This can result in larger resections or conversion to thoracotomy. The goal of this study is to evaluate the role of electromagnetic navigational bronchoscopic localization (ENBL) as a safe and accurate intraoperative method to localize small, deep, or subsolid nodules. Methods: This is a single-institution, single-surgeon retrospective study of all patients (51) who underwent combined ENBL and resection of 54 nodules between May 2013 and August 2015. Localization was performed by intraoperative ENBL-guided transbronchial injection of a liquid marker. The liquid marker used was methylene blue, either alone or in addition to indocyanine green and Isovue. A fiduciary also was added in 2 cases. Immediately after localization, the patients underwent VATS for evaluation before proceeding with RATS for anatomical sublobar resection. Results: The mean preoperative largest nodule diameter on computed tomography scan was 13.3 mm (range, 4-44 mm). The mean distance from the surface of the lung to the middle of the nodule was 22 mm (range, 4-38 mm). Thirty-one nodules were solid (57.4%), whereas 23 were ground-glass opacities (42.6%). ENBL successfully localized the nodules for initial sublobar resection in 53 of 54 nodules (98.1%). Minimally invasive thoracoscopic surgery was performed successfully in 49 of 51 patients (96.1%), by RATS in 47 (92.2%), and VATS in 2 (3.9%). Two patients required conversion to thoracotomy secondary to extensive adhesions. Of the 54 nodules, final diagnosis was adenocarcinoma in 32 (59.2%), metastatic disease in 7 (13%), squamous cell carcinoma in 2 (3.7%), neuroendocrine tumor in 2 (3.7%), and benign in 11 (20.3%). There were no operative mortalities. Morbidities included acute renal insufficiency in 2 patients and prolonged air leak requiring a Heimlich valve in 3 patients. Mean length of stay was 3.9 days. Conclusions: ENBL is a safe and accurate intraoperative modality for targeted sublobar resection of pulmonary nodules that are deemed difficult to localize.