Microsurgical and endovascular treatment of posterior inferior cerebellar artery aneurysms: a systematic review and meta-analysis

INTRODUCTION: Posterior inferior cerebellar artery (PICA) aneurysms are uncommon vascular lesions of the posterior fossa. In addition to aneurysmal morphology, structural anatomic considerations may confer additional procedural risk, and as a result there is currently no consensus as to whether a surgical or endovascular approach offers greater safety and efficacy for patients. EVIDENCE ACQUISITION: We systematically examined peer-reviewed literature describing PICA aneurysm treatment planning from January 2000 to May 2021 using the PRISMA methodology. A meta-analysis of proportions was performed. Certainty of the evidence was assessed using the GRADE approach. EVIDENCE SYNTHESIS: Fifty-eight studies including 1673 PICA aneurysms were analyzed. Overall treatment occlusion rate was 97% (95% confidence interval [CI]: 93-100%) for surgery and 85% (95% CI: 78-92%) for endovascular therapy. The recurrence rate was 6% in the endovascular group and 1% for surgery. Overall morbidity and mortality were 16% and 7%, respectively. Intraoperative complications occurred in 9% of the surgical patients. CONCLUSIONS: Despite a large body of literature, analysis indicates that 62% of studies had moderate or serious risk of bias, suggesting very-low certainty results. Therefore, treatment via either approach should be determined on a case-by-case basis and according to institutional experience.