Direct visualization of postoperative aortobronchial fistula on computed tomography

Area of Science:

• Cardiovascular Surgery
• Thoracic Surgery
• Diagnostic Imaging

Background:

• Postoperative aortobronchial fistula (ABF) is a rare complication following thoracic aortic surgery, with an incidence of 0.3%-5.0%.
• Diagnosis of ABF is challenging due to its rarity and infrequent direct visualization on imaging.
• The latency period for ABF development can be extensive, with diagnosis occurring years after the initial surgery.

Purpose of the Study:

• To explore the correlation between computed tomography (CT) imaging findings and clinical manifestations of ABF.
• To evaluate the diagnostic utility of CT in identifying ABF and associated complications after thoracic aortic surgery.

Main Methods:

• Retrospective analysis of six patients with suspected ABF (identified by perigraft air on CT) between January 2004 and September 2022.
• Review of chest CT findings including direct fistula confirmation, peri-graft changes (fluid, dirty fat, ring enhancement), atelectasis, hemorrhage, and bronchodilation.
• Correlation of CT findings with clinical presentation, complications, and outcomes.

Main Results:

• ABF was diagnosed a mean of 14 years post-surgery; 4/6 patients were asymptomatic initially.
• CT directly confirmed ABF in 67% of cases.
• Peri-graft dirty fat (67%) and ring enhancement (50%) were linked to graft infection; endoleaks/pseudoaneurysms (33%) correlated with hemoptysis.

Conclusions:

• Chest CT is effective in confirming aortobronchial fistulas (ABF) after thoracic aortic surgery, including asymptomatic cases.
• CT imaging plays a vital role in diagnosing ABF and identifying associated complications such as graft infection and hemoptysis.