Use of methylene blue and a spring microcoil in the preoperative localization of small pulmonary nodules under CT guidance: a meta-analysis

OBJECTIVE: Methylene blue (MB) and spring microcoils are used for the preoperative localization of small pulmonary nodules (SPNs). We aimed to compare the efficacy and safety of these methods using published data. METHODS: We identified randomized controlled trials and observational studies that assessed preoperative SPN localization using MB or spring microcoil and compared these using a meta-analysis. RESULTS: Seven studies of 933 patients were identified, in whom 1081 SPNs were located. Four hundred twenty-four SPNs were located using MB (n = 359 participants), and 657 SPNs were located using the spring microcoil method (n = 574 participants). The prevalence of technical success of SPN localization was higher using MB (mean deviation [MD]: 0.43; 95% confidence interval [CI]: 0.20, 0.93); the incidence of postoperative complications was lower (MD: 1.70; 95% CI: 1.09, 2.65); and the time taken for removal was longer (MD: −12.37; 95% CI: −22.60, −2.13). There were no differences with respect to the successful wedge resection rate, the time taken for localization, the duration of the procedure, or the mean hospital stay. CONCLUSIONS: Both methods can detect SPNs; however, MB is associated with a higher success rate and fewer postoperative complications, while spring microcoil localization is associated with more rapid removal.