Fatal aortobronchial fistula.

Aortobronchial fistula is a rare condition characterized by the development of a communication between the aorta and a branch of the bronchial tree that results from processes that arise within the aorta, in the tissues of the mediastinum, or in the adjacent thoracic organs. Three cases are reported to demonstrate characteristic features. Case 1: An 82-year-old woman was found collapsed with blood clot in her mouth. At autopsy an atherosclerotic thoracic aortic aneurysm was found which had eroded into the underlying left main bronchus with filling of the larynx, trachea and main bronchi with fluid blood. There was no evidence of dissection. Case 2: A 30-year-old woman collapsed and died. At autopsy, coarctation of the thoracic aorta was found with a saccular aneurysm distal to this which was joined to the left main bronchus by a mass of necrotic tissue. The bronchus contained a cast of blood; blood was also present within the trachea and within the distal airways of the left lung. Case 3: A six-year-old girl collapsed with massive airway haemorrhage following bronchoscopy. At autopsy coarctation of the thoracic aorta was identified with a saccular aneurysm distal to this. A transverse tear of the thinned aneurysm wall communicated with a mass of necrotic friable tissue that extended through the wall of the left main bronchus. Distal airways were filled with fluid blood. All three deaths were due to haemorrhage from aortobronchial fistulas. The pathogenesis of aortobronchial fistulas involves a variety of mechanical, infective and neoplastic processes. Many cases will not be diagnosed until autopsy examination is performed.