Background Flow diversion (FD) is a commonly used endovascular modality for cerebral aneurysm treatment. While adjunctive coiling combined with flow diversion (FDC) is often used, rates of occlusions and risk of complications remain controversial compared to FD alone.

Methods A PRISMA-guided systematic literature review of the MEDLINE and Cochrane Library databases. Comparative studies evaluating FDC compared to FD alone were included. Meta-analysis was completed to investigate the following outcome variables: rate of occlusion on initial imaging study, rate of occlusion on long term follow-up, need for retreatment, and major complications. Odds ratios (OR) with corresponding confidence intervals (CI) were completed using a random effects model.

Results In total, 16 studies met full inclusion criteria with 3433 total patients. FD alone was used in 2899 patients while adjunctive coiling with FD was used in 534 patients. 2672 aneurysms had descriptions of location, of which 2226 aneurysms treated were anterior circulation and 326 aneurysms treated were posterior circulation. 2174 aneurysms had morphological descriptions, of which, 1,675 were saccular, 430 were either fusiform or dissecting/pseudoaneurysm, 18 were blister and 51 were not categorized in any of the aforementioned groups. There was no difference in complete occlusion at initial post-procedure imaging between FD and FDC (OR: 6.44; 95% CI, 0.78 to 52.87, P = 0.08). However, on long term follow up, FDC was associated with a higher odd of achieving full occlusion compared to FD alone (OR: 1.92; 95% CI, 1.05 to 3.51, P = 0.03). Additionally, there was no significant difference regarding need for retreatment (OR: 0.84; 95% CI: 0.020 to 3.58, P = 0.81) or in occurrence of major complications (OR: 0.81; 95% CI, 0.45 to 1.46, P = 0.49) between the two modalities.

Conclusion Flow diversion with adjunctive coiling facilitates a higher odd of full occlusion at long term follow-up without differences in major complications. Further research regarding risk and benefit stratification based on additional aneurysm characteristics, such as size and location is warranted.

Disclosures R. Ismail: None. D. Schartz: None. N. Ellens: None. M. Bender: None.