Visualization of bronchial circulation at bronchial anastomotic site using bronchial fluorescein angiography technique

OBJECTIVES Successful bronchial healing after a bronchoplastic procedure mainly depends on bronchial circulation at the anastomostic site. We developed a bronchial fluorescein angiography (B-FAG) technique for visualizing circulation on the bronchial surface. The technique was evaluated in animals. METHODS Fluorescein was used as a contrast agent and an autofluorescence imaging (AFI) bronchoscope as a detector. The left main pulmonary artery (PA) and main bronchus of 10 pigs were isolated. After transection of the left main bronchus and bronchial arteries and re-anastomosis of the bronchus, the pigs were randomly divided into two groups: the PA- group (n = 5), in which the pulmonary artery was transected; and the PA+ group (n = 5), in which the pulmonary artery was preserved. Following intravenous injection of fluorescein, the distal anastomotic site was observed for 30 min with autofluorescence imaging bronchoscopy. Bronchial specimens sampled 2 days after the surgical intervention were histologically evaluated. RESULTS In the PA- group, there was no fluorescein enhancement in the distal bronchus throughout the observation time. However, enhancement, which turned the bronchial surface from magenta to bright green, was clearly observed in less than 207 ± 102.5 s in the PA+ group. The enhancement status detected by bronchial fluorescein angiography was related to the extent of tissue damage, as was proven histologically in the acute healing stage. CONCLUSIONS Bronchial fluorescein angiography clearly visualized the circulatory status promptly after the anastomosis procedure at the central bronchus. This technique is a potentially practical approach to predict ischaemic airway complications following bronchial anastomosis.