Advantages and rational application of indocyanine green fluorescence in pulmonary nodule surgery: a narrative review.

Background and Objective: The early detection and early treatment of high-risk pulmonary nodules directly affect the long-term survival rate of patients. However, conventional nodule localization methods, such as hook-wire, technetium-99m, and methylene blue are associated with issues such as a high-frequency of complications, low patient tolerance, serious side effects, and inability to identify pigmented lungs. For patients who require segmentectomy, there is often a lack of effective path planning, resulting in insufficient resection margins or excessive loss of lung function. Therefore, effective and rational nodule localization and surgical approaches are crucial. This narrative review aimed to evaluate the advantages of indocyanine green (ICG) fluorescence in pulmonary nodule surgery and clarify its application in various types of patients. Methods: We searched the PubMed and Web of Science databases from January 2010 to January 2024 using the terms "localization of pulmonary nodules", "localization of pulmonary nodules AND indocyanine green", "localization of pulmonary nodules AND complication", "localization of pulmonary nodules AND surgical planning", and "localization of pulmonary nodules AND underlying lung disease". Information used to write this narrative review was from clinical phenomena, statistical data, and authors' conclusions. Key Content and Findings: The commonly used localization methods of pulmonary nodule such as computed tomography (CT)-guided percutaneous placement of hook-wire are accompanied with serious complications: including hemopneumothorax and ache. Meanwhile, routine dye commonly fails to localize the nodules in patients with anthracosis. ICG with the enhanced permeability and retention (EPR) effect can be used effectively for preoperative and intraoperative localization of pulmonary nodules and its nature of allowing the observance of the condition of pulmonary blood vessels has gradually become a hotspot of research in this field. Conclusions: For nodules with a depth of less than 1 cm, no penetration depth problem is encountered when ICG fluorescence is used. Percutaneous puncture can effectively identify the location of nodules at low cost. Compared with other localization methods, it can effectively avoid problems such as pain, radiation exposure, marker displacement, and the existence of anthrax lesions in the lungs. For patients on whom it is difficult to locate nodules due to tissue results, virtual bronchoscopy or electromagnetic navigation bronchoscopy can effectively identify nodules and reduce complications such as pneumothorax. For patients whose operation is postponed due to fever, sudden cardiovascular and cerebrovascular diseases, there is no risk of nodule localization material detachment by using ICG. ICG can also be used in patients with pulmonary physiological or pathological diseases. Meanwhile, in patients with deep pulmonary nodules, ICG fluorescence can help plan the surgical path, ensure the margin of resection, reduce lung function damage, and prevent bronchial fistula. Therefore, the rational use of ICG fluorescence technology can effectively locate nodules, assist surgeons in planning surgical methods, potentially reducing complications and ultimately improving patient prognosis.