Year: 2026
Type: article
Study design: Case Report
Abstract: Spontaneous disappearance of small unruptured intracranial aneurysms is exceedingly rare, as most reported cases describe resolution in the context of rupture, giant aneurysms, or dissecting lesions. We report two cases of small saccular aneurysms that vanished during long-term magnetic resonance angiography follow-up. In Case 1, a 3.6 × 3.4-mm right internal carotid artery aneurysm demonstrated gradual reduction followed by complete disappearance, coinciding with proximal hemodynamic alteration. In Case 2, a 3.6 × 2.9 mm aneurysm of the right middle cerebral artery remained stable for 7 years before disappearing following asymptomatic M2 branch occlusion. These observations suggest that spontaneous thrombosis may occur even after prolonged morphologic stability, particularly when hemodynamic conditions shift toward reduced flow or altered shear stress. Recognition of this phenomenon is important for follow-up strategies, and additional imaging details are provided in the supplementary material.
Source: Asian Journal of Neurosurgery
Institution: Kanazawa Medical University
Language: English
Subfield: Neurology
Field: Medicine
Domain: Health Sciences
Open Access status: hybrid
OpenAlex ID: W7127318577