Individualized endovascular management of distal posterior circulation aneurysms: a single-center experience and decision framework

Abstract

Purpose Distal intracranial aneurysms (IAs) of the posterior circulation are rare and often pose significant surgical challenges. Although endovascular treatment (EVT) has emerged as an alternative, clear management guidelines remain lacking. We report a single-center experience with EVT for these complex lesions, focusing on procedural outcomes, complications, and follow-up results. Methods We retrospectively reviewed patients with distal posterior circulation IAs who underwent EVT at our institution between January 2017 and December 2024. Treatment strategies were individualized based on aneurysm morphology, vascular access tortuosity, parent artery (PA) caliber, distal collateral circulation, and the functional importance of the PA territory. Outcomes assessed included technical success, perioperative complications, angiographic occlusion, and clinical status at the last follow-up, as measured by the modified Rankin Scale (mRS). Results Nineteen patients (10 men, 9 women; median age 58 years) with 19 aneurysms were included. Aneurysm locations were posterior cerebral artery (n = 8), posterior inferior cerebellar artery (n = 7), anterior inferior cerebellar artery (n = 3), and superior cerebellar artery (n = 1). Fifteen aneurysms were ruptured, and 15 were dissecting in nature. EVT was technically successful in all cases with no intraprocedural complications. Treatment modalities included intra-aneurysmal coiling (n = 7), stent-assisted coiling (SAC, n = 2), and parent artery occlusion (PAO, n = 10). Immediate complete occlusion was achieved in 5/7 coiled aneurysms, 2/2 SAC aneurysms, and all 10 PAO aneurysms. No new neurological deficits occurred in patients who underwent intra-aneurysmal coiling or SAC, while five patients with insufficient collateral circulation who underwent PAO developed territorial infarction with neurological deficits. At a mean follow-up of 8.4 months, all PAO and SAC aneurysms remained stably occluded. However, three of seven coiled aneurysms—all of which were saccular-configured dissecting aneurysms—showed recurrence. No rebleeding occurred. Favorable functional outcomes (mRS ≤ 2) were achieved in 18 patients (94.7%). Conclusion For surgically intractable distal posterior circulation aneurysms, EVT represents a viable alternative. Individualized treatment strategies should be formulated according to aneurysm characteristics, vascular access tortuosity, parent artery caliber, distal collateral perfusion, and whether the PA supplies eloquent brain territories. Appropriate individualized management can yield favorable clinical outcomes in the majority of patients.