Serial CT volume measurements after endovascular aortic aneurysm repair

Purpose: To evaluate the efficacy of transluminal stent-graft placement in aortic aneurysms using postoperative enhanced spiral computed tomographic ( CT) volumetric measurements of the aneurysm sac, the intra-aneurysmal vascu lar channel (IAVC), the thrombus, and the stent-graft. Methods: Among 53 patients (45 men; mean age 74 years, range 59-85) who und erwent elective endovascular aortic aneurysm repair, 37 patients with 27 ab dominal and 10 thoracic aortic aneurysms completed at least a 6-month follo w-up that included computerized CT volumetric analysis prior to discharge a nd at 3, 6, 12, 24, and 36 months. A variety of bifurcated (n=23) and tube (n=14) stent-grafts were observed for signs of endoleak and aneurysm enlarg ement. Results: Mean follow-up was 16 months (range 6-48). Total aneurysm volumes and thrombus volumes decreased, whereas IAVC and stent-graft volumes increa sed over time. Between the postoperative and 12-month imaging studies, redu ctions in total aneurysm (p=0.011) and thrombus (p<0.001) volumes were sign ificant. No statistically significant difference in volume changes for the aneurysm sac (p=0.555) or the thrombus (p=0.920) was found when comparing t he 24 patients without primary leak to the 12 with primary type-II leak. In all 5 cases with secondary leak, the volume of the aneurysm sac increased after initial shrinkage. C onclusions: Postoperative CT volumetric analysis is an effective tool for e valuating the outcome of endovascular aortic aneurysm repair. Thrombus volu me measurements are more accurate than total aneurysm volumes. In patients in whom contrast agents are contraindicated, volume measurements can also b e obtained without the use of contrast.