A New Method for the Detection of Air Leaks Using Aerosolized Indocyanine Green

Efficient methods for the detection and repair of pleural defects are crucial for preventing postoperative air leaks; however, there are few studies on sealing test methods. We developed a new sealing test method that involves the administration of aerosolized indocyanine green into the airway. This experimental study aimed to confirm whether this method could identify alveolar-pleural fistulas.

Thoracotomy was performed on 6 beagles under general anesthesia. Pleural defects accompanying air leaks were created in the cranial and caudal lobes. Using a pediatric jet nebulizer kit, 5 mL of 2.5 mg/mL aerosolized indocyanine green solution was administered to the entire lung through a catheter placed in the trachea. Pleural defects were observed using a near-infrared light scope, and the time until confirmation of the defect sites was measured.

Of the 25 pleural defect sites created, 24 could be identified under a near-infrared light camera. The average time required for confirming the site of pleural defect was 13.8 seconds (95% confidence interval, 7.32-16.8 seconds).

By administering aerosolized indocyanine green into the airway, the site of alveolar-pleural fistula could be identified with a near-infrared light camera in a canine pleural defect model. This method could be a valid sealing test and is suitable for video-assisted thoracic surgery, as it allows for observation of the lung in a collapsed state with a long observation time. Further studies are needed to determine the optimal dose of indocyanine green and to confirm the method's applicability and efficacy in humans.