Computed Tomography-Guided Methylene Blue Localization: Single vs. Multiple Lung Nodules

Background: Preoperative localization for small invisible and impalpable pulmonary nodules is important in single-port video-assisted thoracoscopic surgery (VATS). Localization of multiple pulmonary nodules during VATS resection remains challenging. The aim of our study is to elucidate the efficacy of preoperative CT-guided methylene blue localization of both single and multiple pulmonary nodules. Methods: Consecutive patients undergoing preoperative CT-guided methylene blue dye localization for lung nodules, followed by VATS resection, were retrospectively analyzed between January 2014 and November 2019. Chi-square tests, Fisher's exact test and independent T-test were used to compare variables between the groups. Logistic regression was used to identify risk factors for procedure-related complications. Results: A total of 388 patients, including 337 with single nodule and 51 with multiple nodules, were analyzed. The success rate of preoperative CT-guided methylene blue localization for both single and multiple pulmonary nodules were comparable as 98.8% (333/337) vs. 100% (108/108). The procedure time was longer (23.2 +/- 9.4 vs. 7.6 +/- 4.8 min, p < 0.001) and risk of pneumothorax was higher (47.1 vs. 25.5%, p = 0.002) in the multiple nodule group. The procedure time (OR 1.079; 95% CI = 1.041-1.118; p < 0.001) was an independent risk factor for pneumothorax. Nodule depth (OR 2.829; 95% CI = 1.259-6.356; p = 0.011) was an independent risk factor for pulmonary hemorrhage. Conclusions: Preoperative CT-guided methylene blue localization for both single and multiple pulmonary nodules is safe, feasible, and effective.

Automated summary

This study investigated the efficacy of preoperative CT-guided methylene blue localization for both single and multiple pulmonary nodules in single-port video-assisted thoracoscopic surgery. The success rate of localization was comparable between single and multiple nodules, but the procedure time and risk of pneumothorax were higher in the multiple nodule group. Nodule depth was identified as an independent risk factor for pulmonary hemorrhage.