Aortobronchial fistula:
Clinical:
An aortobronchial fistula is a rare cause of hemoptysis. Etiologies include chronic infection, neoplasm, thoracic aortic aneurysm (especially mycotic), and prior vascular surgery. Patients present with recurrent hemoptysis- usually beginning with small quantities. The episodic nature of the hemoptysis is related to clot formation within the fistula. The average time between the first episode of hemoptysis and fatal hemorrhage is nearly 5 months. Bronchoscopy is the test most likely to identify the site of bleeding and the fistulous tract may be directly visualized. Unfortunately, the procedure may dislodge a clot and result in massive bleeding.X-ray:
Findings on CT include a thoracic aortic aneurysm with ground-glass opacity in the adjacent lung. The fistula itself may be seen in up to 50% of cases.The fistula is usually filled with clot and may not be evident on angiography. Catheter manipulation also poses the risk of precipitating hemorrhage.
REFERENCES:
(1) AJR 1998; Foster CL, et al. Aortobronchial fistula occuring after coarctation repair: Findings on aortography, helical CT, and CT angiography. 171: 401-402
