Indocyanine green inhalation visualizes lung tumour during video-assisted thoracoscopic surgery.

Objectives: Accurate intraoperative identification of small lung tumours is crucial for precise resection of these lesions during video-assisted thoracoscopic surgery. This study aimed to evaluate the feasibility and safety of indocyanine green (ICG) inhalation for intraoperative visualization of lung tumours.

Methods: From January 2022 to May 2022, 43 patients with lung nodules were included into this study. All patients received intraoperative ICG inhalation for visualization of lung tumours under near-infrared imaging. The primary outcomes of this trial were the detection rate and background-tumour ratio of lung nodules, and the secondary objectives were time to search for nodules and operative time to nodules excision.

Results: A total of 50 pulmonary nodules in 43 patients were identified and completely resected. And 44 lung nodules were detected during intraoperative fluorescent exploration with a median inhaled ICG dose of 18.8 mg. In vivo, the median background-tumour ratio was 7.10. The median detection time of nodules was 100 s and the median operative time to nodules excision was 18 min. Quantification analysis showed that the fluorescence intensity of postoperative sputum declined to ∼10% of the first fluorescent sputum within 20 h. No adverse events attributed to ICG inhalation were recorded during the follow-up period.

Conclusions: Intraoperative inhalation of ICG was a feasible and safe method for detection of lung tumours at low dose of ICG. This technique could be a remedial measure for identification of unpalpable lung nodules without preoperative localization.

Trial Registration: Chinese Clinical Trial Registry, Identifier: ChiCTR2100053708.