Distal posterior inferior cerebellar artery dissecting aneurysms: a systematic review and meta-analysis.

Abstract

Distal posterior inferior cerebellar artery (PICA) dissecting aneurysms are rare, anatomically complex, and clinically underreported. Management strategies remain poorly standardized, and long-term outcomes are not well defined. This paper aims to systematically review the anatomical, clinical, and therapeutic characteristics of distal PICA dissecting aneurysms. Following PRISMA guidelines, a comprehensive search of PubMed and SCOPUS identified 15 eligible studies, including 68 patients. Data on clinical presentation, aneurysm characteristics, treatment strategies, and outcomes were extracted. Pooled proportions and meta-analyses were conducted using random-effects models. Among 68 patients, 91.2% presented with subarachnoid hemorrhage. Endovascular treatment was preferred (69.1%), achieving a higher complete occlusion rate (90%) and low retreatment (9%), and rebleeding rates (8%). Surgical treatment (23.5%) had similar efficacy (81% occlusion). The complete occlusion rate was not significantly different between the two (OR: 1.43; log OR = 0.360; 95% CI: -0.848 to 1.569, p = 0.559). Functional outcomes were favorable overall, with 79.4% of patients achieving mRS < 2. Stroke was the most frequent complication (14.2%). No significant differences were found between reconstructive and deconstructive approaches (p = 0.971). Flow diversion was not utilized in any case. Distal PICA dissecting aneurysms, though uncommon, pose a high risk of hemorrhage. Endovascular parent artery occlusion offers high occlusion rates with low morbidity. The absence of flow-diversion strategies highlights current device limitations and illustrates the need for anatomy-specific, prospective studies to guide optimal management.