COMPLEX RIGHT ICA ANEURYSM WITH COLLATERAL REFORMATION: A CASE REPORT

Abstract

A 34-year-old female presented for evaluation of an incidentally detected intracranial aneurysm on CT cerebral angiography. Imaging revealed a complex aneurysm involving the supraclinoid segment of the right internal carotid artery (ICA), consisting of a fusiform dilatation with peripheral wall calcification and an associated saccular component measuring 5.5×7.0×6.1 mm. The M1 segment of the right middle cerebral artery (MCA) was markedly attenuated, yet the distal MCA branches (M2–M4) were opacified, likely via collateral circulation. The A1 segment of the right anterior cerebral artery (ACA) was reduced in calibre (possible hypoplasia). Venous anomalies including hypoplasia of the left transverse and sigmoid sinuses were also noted. There was no evidence of subarachnoid or intraparenchymal hemorrhage, thrombus, or arteriovenous malformation. This case highlights a complex, unruptured aneurysm in a young adult, with associated vascular anomalies and collateral-dependent distal perfusion. Given the absence of hemorrhage and the high surgical risk, conservative management with rigorous blood pressure control, lifestyle modification, and serial imaging surveillance was instituted. The case underscores the importance of individualized decision-making in complex cerebrovascular lesions.