Aortopulmonary fistula: role of computed tomography.

A 67 year old man presented with a two month history of haemoptysis-10-20ml of fresh blood about once a week. Eight years earlier he had undergone elective resection of a saccular aneurysm of the descending thoracic aorta of unknown aetiology. The aneurysm only had been excised and a Dacron onlay patch had been inserted. He had made an uneventful recovery and remained well until October (a) 1985. He gave up smoking at the time of that operation. Physical examination showed a well healed thoracotomylW wound but nothing else of note. Routine haematological and _ biochemical investigations showed no abnormality. A lateral 7 chest radiograph showed mild dilatation of the descending aorta. Bronchoscopy revealed some fresh blood in the left lower lobe posterior basal segmental bronchus. Cytological examination of sputum gave normal results. Computed tomography was performed, 50ml N. nam 300 being used as enhancement. This showed an aneur, mn of the mid third of the descending aorta (fig la) adjacent a large airway (fig lb). An aortogram confirmed the pres.nce of a small aneurysm at this site but did not show a fistula. In view of the continuing haemoptysis we proceeded to an exploratory left thoracotomy on 11 December 1985. Mobilisation of the left lower lobe revealed an area of the posterior basal segment that was densely adherent to a false Fig 1 (a) Compute aneurysm arising from the edge of the original Dacron shows a smallfalse a patch. The lower lobe was separated from the aorta at this Pulmonary cut show point and aorto-aortic bypass established with a 9mm hepabronchus. rinised Gott shunt. The false aneurysm, Dacron patch, and fistula were excised (fig 2), together with a complete circumference of aorta. The repair was performed with an interposition graft of low porosity Meadox Dacron. A pleural flap was raised to separate the graft from the lower lobe. A small amount of the posterior basal segment was resected with the false aneurysm and the remaining lung repaired with a stapler. The patient made a straightforward recovery and was well and active on review eight months later. Histological examination of the aorta showed severe ath-