Most fistulae occur between the thoracic descending aorta and left bronchus.
Risk factors:
(1) aortic pseudoaneurysm following trauma or surgery
(2) true aortic aneurysm
(3) penetrating trauma
(4) mycotic aneurysm of the aorta
Clinical features:
(1) hemoptysis, which may be recurrent and which is eventually massive
(2) variable hoarseness (cardiovocal syndrome)
(3) variable chest pain
(4) variable cough
(5) variable dyspnea
A plain chest X-ray may show the aneurysm but is relatively insensitive. A CT scan or MRI is often diagnostic.
Reasons for a delayed diagnosis:
(1) failure to consider diagnosis since it is rare
(2) failure to identify risk factors
(3) nonspecific findings
(4) minimal or intermittent hemoptysis
(5) failure to order a CT scan or MRI
(6) angiography may be inconclusive if an occlusive clot prevents flow of contrast material
Bronchoscopy may show elevation of the mucosa over the encroaching aorta and/or fresh blood. The bronchoscope can dislodge an occlusive clot, which may be precipitate serious hemorrhage.
The prognosis is poor if the diagnosis is delayed. Early diagnosis with prompt therapy can be life-saving. Many cases can be managed by an endocascular approach.
