Matched Comparison of Flow Diversion and Coiling in Small, Noncomplex Intracranial Aneurysms

Background: Flow diversion is typically reserved for large, giant, or morphologically complex aneurysms. Coiling remains a first-line treatment for small, morphologically simple aneurysms.

Objective: To compare coiling and flow diversion in small, uncomplicated intracranial aneurysms (typically amenable to coiling).

Methods: Forty patients treated with the pipeline embolization device (PED) for small (<10 mm), morphologically simple aneurysms that would have also been amenable to coiling were identified. These patients were matched in a 1:1 fashion with 40 patients with comparable aneurysms treated with coiling. Matching was based on age, gender, aneurysm size, and aneurysm morphology.

Results: The 2 groups were comparable with regard to baseline characteristics including age, gender, and aneurysm size. The complication rate did not differ between the 2 groups (2.5% with coiling vs 5% with PED; P = .6). Multivariate analysis did not identify any predictor of complications. Complete occlusion (100%) at follow-up was significantly higher in patients treated with PED (70%) than coiling (47.5%, P = .04). In multivariate analysis, treatment with PED predicted aneurysm obliteration ( P = .04). A significantly higher proportion of coiled patients (32.5%) required retreatment compared with flow diversion (5%, P = .003). In multivariate analysis, coiling predicted retreatment ( P = .006). All patients achieved a favorable outcome (modified Rankin Scale: 0-2) regardless of group.

Conclusion: This matched analysis suggests that flow diversion provides higher occlusion rates, lower retreatment rates, and no additional morbidity compared with coiling in small, simple aneurysms amenable to both techniques. These results suggest a potential benefit for flow diversion over coiling even in small, uncomplicated aneurysms.