Long-Term Follow-up of Aneurysms Treated with Hydrogel-Coated Coils Shows Progressive Thrombosis and Improvement in Raymond–Roy Classification

Abstract

BACKGROUND: Coil embolization of aneurysms has been shown to be a safe and effective method of aneurysm treatment. Hydrogel-coated coils were developed as a hybrid embolization device to increase the packing density of a coil mass in an aneurysm and to reduce retreatment and rerupture rates. Previous studies have shown a benefit compared with bare metal coils. OBJECTIVE: To present long-term follow-up of a cohort of patients treated with hydrogel-coated coils to better determine the effectiveness compared with bare platinum coils. METHODS: Between January 2003 and April 2012, we identified patients with both ruptured and unruptured aneurysms coiled at our institution, using some portion of hydrogel-coated coils. Planned follow-up angiography was performed at 6 months, 18 months, and 5 years post-treatment. All imaging was independently adjudicated by a single physician at a separate institution. The results were scored with the modified Raymond–Roy Occlusion Classification. RESULTS: A total of 145 patients with 153 treated aneurysms were included in the study analysis. Immediately after treatment, 49% of aneurysms were classified at Raymond–Roy Occlusion Classification I or II, which improved to 83% by 6 months. This percent plateaued at 18-month and 5-year follow-up, measuring 86% and 90%, respectively. The retreatment rate was 14% over the 5-year period, and there were no rerupture events captured. CONCLUSION: Treatment of intracranial aneurysms with coil embolization using hydrogel-coated aneurysms shows evidence of progressive occlusion, particularly over the first 6 months of follow-up. The retreatment rate is comparable with historical data, and the rerupture rate is low.