Abstract WP130: Long Term Outcome of Large and Giant Unruptured Intracranial Aneurysms

Abstract

Objectives: Long term outcome of large / giant unruptured intracranial aneurysms (LG-UIAs) after endovascular therapy is still unknown. We retrospectively analyzed long-term results of patients with LG-UIAs who were followed up more than 5 years after endovascular therapy. Methods: We included patients from our complete database with UIAs greater than 10mm and treated at our hospital from January 2003 to December 2013. Retreatment rate of targeted aneurysms, rupture rate, and the modified Rankin scale (mRS) at last visit were evaluated till December 2018. Results: From 142 patients treated during the period were excluded 3 patients with perioperative rupture and 38 patients with less than 5 years follow-up period, finally analyzing 101 patients. The median aneurysm size was 12.0 mm (IQR 10.8-15). The median follow-up period was 9.4 years (IQR: 7-11), the longest being 13.3 years. Retreatment was performed on 36 patients (35.6%). Comparing cumulative re-treatment rates in groups with aneurysm sizes <15 mm and> 20 mm, it was predominantly higher for aneurysms> 20 mm (P = 0.02, Figure1 ). Rupture of targeted aneurysms was observed in 2 cases (1.98%, Figure2 ), and the longest period from last treatment was up to 12 years. The mRS 0-1 at the first treatment and the final visit were 98% and 93%, respectively, and mRS deterioration remained at 5%. Conclusion: The retreatment rate tended to increase in proportion to the size of the aneurysm, however the final neurological outcome was favorable when considering the natural history of these aneurysms. Since aneurysmal rupture could occur after 12 years of treatment, long-term follow-up should be considered for LG-UIAs.