A Location-Based Tailored Endovascular Strategy for Managing Posterior Inferior Cerebellar Artery Aneurysms: A Single-Center 46-Case Series

BACKGROUND AND OBJECTIVES: To evaluate the clinical and angiographic outcomes of endovascular treatment for posterior inferior cerebellar artery (PICA) aneurysms, emphasizing a location-specific treatment stratification based on PICA segmental anatomy. METHODS: Patients with PICA aneurysms treated endovascularly between December 2016 and December 2024 were retrospectively analyzed. The PICA is classified into 5 segments, with the first 3 (P1-P3) designated as proximal and the P4-P5 as distal. We assessed the immediate and progressive aneurysm occlusion rates, procedure-related complications, and clinical outcomes. RESULTS: Forty-six patients (each with 1 PICA aneurysm; 37 ruptured) were included. Twenty-five aneurysms (54.3%) were located in the proximal PICA and 21 (45.7%) in the distal segments. Technical success was achieved in all procedures. Parent artery preservation was accomplished in all proximal aneurysms, treated with either coiling (n = 16) or stent-assisted coiling (n = 9). Most distal aneurysms (66.7%, 14/21) were treated with parent artery occlusion. Intraprocedural ischemic events occurred in 4 patients (8.7%), with one fatal in-stent thrombosis. Intraprocedural aneurysm rupture occurred in one case (2.2%). Postprocedural infarction was observed in 3 patients (6.5%), all of whom had unfavorable clinical outcomes at follow-up. Immediate postprocedural angiography revealed complete occlusion (Raymond Grade I) in 67.4% (31/46) of cases, increasing to 97.3% (36/37) at follow-up, with no recurrence. Favorable clinical outcomes (modified Rankin Scale: 0-2) were achieved in 76.1% of patients. CONCLUSION: An anatomy-based tailored endovascular approach for PICA aneurysms yields encouraging clinical and angiographic outcomes, with proximal lesions amenable to coiling or stent-assisted coiling and distal lesions effectively managed with parent artery occlusion.