Unmasking thrombosed abdominal aortic aneurysm: diagnostic pitfalls from a surgical case series

Background: Computed tomography angiography (CTA) with 3D reconstructions and digital subtraction angiography (DSA) is the diagnostic cornerstone for aortic pathology. This case series highlights a critical diagnostic pitfall: thrombosed abdominal aortic aneurysms (AAAs) that mimic simple aortic occlusions on 3D reconstruction images and DSA a finding with significant implications for surgical management. Methods: We retrospectively reviewed all cases of radiologically diagnosed infrarenal aortic occlusion at the National University Hospital (previously known as Al-Assad University Hospital), Damascus, between January 2023 and January 2025 (n = 30). Within this cohort, we identified three cases where a discrepancy existed between the findings on 3D reconstructed/DSA images and those on axial CTA source images. Case Series: Three male patients, all active smokers presenting with chronic lower limb ischemia, were initially diagnosed with infrarenal aortic occlusion based on 3D reconstruction images and DSA. However, in all three cases, careful review of the axial CTA source images revealed a thrombosed infrarenal abdominal aortic aneurysm (AAA). The intraoperative diagnosis of a thrombosed aneurysm was established during successful open surgical repair in all cases, which involved the placement of a 16 × 8 mm Dacron graft via an end-to-end aortic anastomosis . Conclusion: In our institutional experience, this specific diagnostic finding was present in 3 of 30 cases (10%) initially diagnosed as aortic occlusion at the National University Hospital over the last 3 years. Consequently, meticulous review of axial source images is indispensable to ensure accurate diagnosis and appropriate surgical planning for thrombosed AAAs masquerading as simple occlusions.