Thoracic CT findings following endovascular stent-graft treatment for thoracic aortic aneurysm.

Purpose: To investigate the transient computed tomographic (CT) findings and morphological characteristics of the descending thoracic aorta following endovascular repair of thoracic aortic aneurysm (TAA).

Methods: Of 50 TAAs repaired using custom-made endoprostheses between May 1997 and September 2005, 35 (25 men; mean age 67 years) were successfully treated and followed for >3 months by thoracic CT. The TAA etiologies were 22 degenerative/atherosclerotic, 7 dissection-related from intramural hematoma, 2 traumatic, 2 anastomotic, and 2 penetrating ulcers. The CT findings following stent-graft placement were retrospectively studied.

Results: Over a mean follow-up of 27.0+/-25 months (range 3-92), periaortic changes were observed in 17 (48.6%) patients, and the amount of pleural effusion increased in 13 (37.1%). In all cases, these findings disappeared without specific treatment during the follow-up period. Late secondary endoleak was observed in 1 (2.9%) patient, and there was 1 (2.9%) caudal migration of the proximal end of the stent-graft. Five (14.3%) aneurysms increased in size. Two patients, both with dissection, showed aortic neck dilatation. There was a positive relationship between neck dilatation and dissection-related TAA etiology (p = 0.035).

Conclusion: Although aortic neck dilatation is less common after endovascular TAA repair than after abdominal repairs, patients with dissection-related TAA may be a subgroup prone to aneurysm neck dilatation.