Clinical significance of spread of lipiodol marking for pulmonary nodules and its influence on surgery

Objective Computed tomography (CT)-guided lipiodol marking is one of the targeting methods for resecting small pulmonary nodules or ground-glass nodules in video-assisted thoracic surgery (VATS). However, lipiodol spreading during marking has not been assessed, practically. In this study, we examined the clinical significance and the influence of lipiodol spreading on surgery. Methods From April 2010 to March 2021, 176 pulmonary nodules in 167 patients were marked with lipiodol under CT guided before VATS. The marking images after lipiodol injection were classified into “Spread” and “non-Spread.” Lung resection was sequentially performed on the same day. Results All target nodules were successfully resected in VATS. In the classification of marking images, Spread was 32 (18%), non-Spread was 144 (82%). There was a significant difference in duration of surgery (mean; 138.7 min vs. 118.3 min, p = 0.0496) and amount of bleeding (mean; 32.7 g vs. 11.2 g, p = 0.0173). Provided that limited to the data of wedge resections without intrathoracic pleural adhesion ( n = 117), there was no significant difference in duration of surgery (mean; 104.8 min vs. 99.6 min, p = 0.48), amount of bleeding (mean; 4.9 g vs. 5.3 g, p = 0.58). In the multivariate logistic regression analysis, the risk factor of lipiodol spreading was intrathoracic pleural adhesion (odds ratio: 3.16, 95% confidence interval: 1.12–8.97, p = 0.03). There was no relationship between marking image and complication rate. Conclusions Lipiodol spreading did not directly influence surgery and complication. However, it was a sign of intrathoracic pleural adhesion, which could lead to increased duration of surgery and amount of bleeding.