Endoleak characterization after endovascular aortic aneurysm repair using dynamic CT angiography

Introduction: Accurately characterizing the types of endoleaks following endovascular aneurysm repair (EVAR) can often be challenging with standard triphasic CT angiography. Dynamic CT angiography is a relatively new CT imaging technique that may enable more precise characterization of endoleaks following EVAR. Method: Between January 2022 and January 2023, dynamic CT angiography acquisitions were performed on 15 patients following EVAR due to uncertain etiology of endoleaks or growing aneurysms using a Philips Brilliance iCT 256 scanner. Depending on the region of interest and the presumed type of endoleak, 12-18 image series were recorded during the examinations, with a 16 cm cranio-caudal coverage and intervals of 4.4 seconds, or 8 cm coverage with intervals of 0.8-2 seconds. The dynamic CT angiography image series were analyzed using the Philips IntelliSpace Portal Functional CT software based on the temporal changes in Hounsfield units in selected regions of interest. Results: Average age was 74.7 +/- 9.3 years, with 10 males and 5 females among the patients. Following precise identification of arteries causing retrograde perfusion, two cases previously classified as Type V endoleaks were reclassified as Type II. In five cases with known Type II endoleaks, dynamic CT angiography identified that the inferior mesenteric artery and/or lumbar arteries were the main perfusion sources. In seven cases where endoleak types could not be clearly determined in previous examinations, exact types of endoleaks were successfully identified. In one case, a Type II endoleak from the inferior mesenteric artery was suspected during EVAR follow-up CT angiography, however, subsequent dynamic CT angiography showed no endoleak and an occluded inferior mesenteric artery. Conclusion: The dynamic CT angiography can serve as a promising adjunct to standard triphasic CT angiography examination following EVAR for characterizing difficult-to-diagnose endoleaks and aiding in the planning of future targeted therapeutic interventions. Orv Hetil. 2025; 166(18): 704-709.