Effect of lipiodol and methylene blue on the thoracoscopic preoperative positioning

Area of Science:

• Pulmonary imaging and interventional procedures
• Radiopaque contrast agents
• Preclinical research

Background:

• Accurate lung nodule localization is critical for effective diagnosis and treatment.
• Traditional methods using methylene blue alone have limitations in staining capacity and visualization.
• Lipiodol, a radiopaque agent, combined with methylene blue may enhance localization accuracy.

Purpose of the Study:

• To compare the site-specific accuracy of a lipiodol and methylene blue mixture (MLM) versus pure methylene blue for lung positioning in a rabbit model.
• To evaluate the staining degree, capacity, and radiopacity of MLM and methylene blue.
• To assess the positioning accuracy and suitability for clinical application.

Main Methods:

• CT-guided percutaneous injection of MLM (0.6 ml, 1:5) and pure methylene blue (0.5 ml) into rabbit lungs.
• Evaluation of staining degree via lung tissue biopsy.
• Assessment of site-specific accuracy using a 4-point system at 6 and 24 hours post-injection.
• Evaluation of MLM radiopacity and direct vision during positioning.

Main Results:

• MLM demonstrated significantly higher staining capacity (2.8 vs. 2.2) and excellent staining ability (81% vs. 38%) compared to methylene blue.
• While MLM had a smaller staining range (0.6 cm vs. 1.0 cm), its radiopacity was acceptable or excellent in 62% of cases.
• MLM achieved a 100% suitable positioning rate with good direct vision, outperforming methylene blue.

Conclusions:

• Percutaneous injection of MLM is a viable method for lung positioning in preclinical models.
• MLM shows superior performance over pure methylene blue in terms of staining capacity and positioning accuracy.
• Further investigation in human subjects is warranted to confirm the clinical feasibility of MLM for lung localization.