Abstract 371: Using Double Pipeline Endovascular Devices to Treat a Rare Dolichoectatic Fusiform Loop‐Donut Shaped Aneurysm of The Anterior Cerebral Artery

BACKGROUND Donut‐shaped dolichoectatic fusiform aneurysms are among the rarest and most technically demanding vascular anomalies, with their complex 360° geometry rendering conventional endovascular strategies high‐risk and difficult to manage. Owing to their rarity, current treatment paradigms remain poorly defined, and surgical clipping has traditionally been the mainstay of therapy. This report presents the first demonstration of the technical feasibility of telescoping double Pipeline flow diverters across a complete arterial loop, achieving durable flow diversion with strong wall apposition, no significant intimal hyperplasia, and robust flow stagnation. METHODS A 40‐year‐old woman with progressive neurological symptoms, prior meningioma resection, and a dolichoectatic fusiform loop‐donut aneurysm of the ACA A2 segment. Given the growth of the aneurysm compared to previous scans, with the formation of two daughter sacs on the diagnostic angiogram, and after a multidisciplinary evaluation including the patient's preference, we opted to treat the aneurysm using a novel endovascular approach; Two Pipeline Flex Embolization Devices (2.5×20 mm and 3×14 mm, MEDTRONIC, Irvine, CA) with Shield Technology were deployed in a telescoping 360° configuration across the aneurysm loop to maximize endoluminal coverage and flow diversion. RESULTS This innovative strategy achieved marked intra‐aneurysmal flow stagnation and maintained parent vessel patency, as confirmed by post‐procedural angiography and MRA. The patient remained neurologically intact both immediately and at follow‐up, with no significant intimal hyperplasia noted on follow‐up 6‐month DSA and 1‐year MRA. CONCLUSIONS This case represents, to the best of our knowledge, the first demonstration of an endovascularly treated intracranial ACA A2 fusiform 360° donut aneurysm using telescoped double Pipeline flow diverter deployment, highlighting an innovative option for lesions previously considered nearly exclusive to surgical clipping. Overlapping flow diverters in a 360° configuration enable comprehensive endoluminal reconstruction while maintaining reasonable flow diversion properties, offering a promising endovascular solution in cases with distal access and challenging anatomy. Keywords: Pipeline Embolization Device, donut‐shaped aneurysm, anterior cerebral artery, flow diversion, fusiform aneurysm, endovascular treatment. image