Introduction Giant intracranial aneurysms are rare vascular lesions consisting of aneurysms measuring ≥25 mm in diameter. These aneurysms arise in specific regions within the circle of Willis, as they tend to be located where they can grow and remain asymptomatic without rupturing for many years. Their formation is the result of multiple factors including their association with a unique genomic landscape.

Methods We performed a systematic review of the literature through the PubMed, Scopus and, Web of Science databases according to PRISMA guidelines. We aimed to identify prior reports involving multimodality management of giant intracranial aneurysms. Specifically, we sought to highlight the integral role of both neuroendovascular and microsurgical interventions in treatment of these rare vascular lesions.

Results 10 studies reporting outcomes for 91 patients were included in this meta-analysis. Mean age varied from 39.0 to 60.1 years. Many were found extending off of the supraclinoid ICA. Overall mortality rate associated with multimodal management of 5.4% was noted. Radiographic obliteration rates were reported in 3/10 studies included. Further, 1 study reported an 82.9% rate of successful obliteration, while the remaining studies achieved 100% rates of obliteration across 15 patients in total. Bypass patency rates ranged from 94.3% to 100%. Rates of good outcomes (mRS 0–2, GOS 4–5) ranged from 60% up to a maximum of 87.5%.

Conclusion Combined, multimodality endovascular and microsurgical treatments appear to be most successful for the treatment of giant aneurysms because of their adaptability, the flexibility they confer, and the synergistic effect of combining the strengths of multiple modalities.

Disclosures N. Brown: None. Z. Pennington: None. S. Patel: None. R. Rahmani: None. J. Catapano: None. M. Lawton: None.