Hydrogel-Coated Versus Bare Platinum Coils for Intracranial Aneurysm Embolization

Background: Aneurysm recurrence after endovascular coiling remains an important limitation in the treatment of intracranial aneurysms. Hydrogel-coated coils were developed to increase packing density and improve the durability of aneurysm occlusion. Objective: To compare the efficacy and safety of hydrogel-coated coils versus bare platinum coils in patients undergoing endovascular embolization of intracranial aneurysms. Methods: A meta-analysis of randomized controlled trials comparing hydrogel-coated coils with bare platinum coils was performed. The primary outcome was major recurrence or recanalization, as defined by each included study. Secondary outcomes included retreatment and mortality. Risk ratios (RRs) with 95% confidence intervals (CIs) were calculated using a random-effects model. Results: Six randomized controlled trials including 2,551 patients were analyzed. Major recurrence/recanalization occurred in 193 of 1,278 patients in the hydrogel group and 268 of 1,273 patients in the bare platinum group. Hydrogel-coated coils were associated with a significantly lower risk of major recurrence/recanalization compared with bare platinum coils (RR 0.73; 95% CI 0.60-0.87; p<0.001; I 2 =12.7%). Retreatment was lower with hydrogel-coated coils but did not reach statistical significance (RR 0.75; 95% CI 0.50-1.12; p=0.164; I 2 =18.2%). Mortality did not differ significantly between groups (RR 1.29; 95% CI 0.70-2.38; p=0.417; I 2 =27.9%). Conclusion: Hydrogel-coated coils were associated with a significant reduction in major aneurysm recurrence or recanalization compared with bare platinum coils, without a significant difference in retreatment or mortality. These findings support an angiographic durability benefit of hydrogel-coated coils.