Purpose: To determine the optimal postoperative imaging modality for the follow-up of patients with endoluminal aortic stent grafts.
Material and methods: From August 1994 to November 1997, 214 patients (194 male and 20 female) with abdominal and thoracic aortic aneurysms were treated with endovascular stent grafts. 137 patients (129 male, 8 female) with 89 tube grafts and 48 bifurcated grafts (45 EVT, 88 Stentor/Vanguard, 3 Chuter, 1 Talent) were evaluated with contrast-enhanced spiral-CT, duplex ultrasound, and DSA at a mean follow-up of 11.1 months.
Results: We found 12 persistent primary endoleaks (8.8%), 17 secondary endoleaks (12.4%), 8 limb occlusions (5.8%), 28 endoluminal thrombi lining the stent graft (20.4%), and 26 suture breakages of the stent frame (19%). In 9 patients (6.6%) the proximal end of the stent partially covered the renal arteries. In 3 patients (2.2%) a partial renal infarction was seen. Spiral-CT was able to demonstrate all the above changes except for 3 sidebranch endoleaks that were documented by duplex ultrasound only and 8 suture breaks seen on abdominal plain films only. The median aneurysm diameter decreased from 48 mm pre-operatively to 46 mm at 24 months post-operatively in patients with endoleaks and from 44 mm to 36 mm in patients without endoleak. For several patients the decreasing aneurysm diameter did not reliably correlate with complete exclusion of the aneurysm.
Conclusion: For follow-up of endoluminal aortic stent grafts contrast-enhanced spiral-CT is superior to duplex ultrasound. DSA is necessary only for patients with complications requiring a secondary intervention.