Immediate Clinical Outcome of Patients Harboring Unruptured Intracranial Aneurysms Treated by Endovascular Approach

TLDR

Management of unruptured intracranial aneurysms is controversial and prospective outcomes of endovascular treatment are lacking. The ATENA study aimed to prospectively assess clinical outcomes and risks of endovascular treatment for unruptured intracranial aneurysms. In a prospective cohort of 649 patients with 1100 aneurysms, 739 unruptured aneurysms were treated endovascularly—mostly with coils alone (54.5%), balloon remodeling (37.3%) or stenting (7.8%)—across 700 procedures at 27 centers. Endovascular treatment failed in 4.3% of aneurysms, with technical adverse events in 15.4% of patients (including thromboembolic, rupture, device problems), and 5.4% experienced neurological deficits or death; 1‑month morbidity and mortality were 1.7% and 1.4%, demonstrating feasibility with low morbidity and mortality.

Abstract

Background and Purpose— The management of unruptured intracranial aneurysms remains controversial and the results of endovascular treatment are not precisely known because no prospective data exist. The first prospective multicenter study (ATENA) was conducted in Canada and France to determine clinical outcome and risks of this treatment. Methods— Six hundred forty-nine patients harboring a total of 1100 aneurysms from 27 Canadian and French neurointerventional centers were prospectively and consecutively treated by endovascular coil embolization. Of these, 739 unruptured intracranial aneurysms were treated during 700 procedures. Aneurysms were selectively treated in the great majority of cases (98.4%) with coils alone (54.5%), the balloon remodeling technique (37.3%), or stenting (7.8%). Results— Endovascular treatment failed in 32 aneurysms (4.3%). Technical adverse events with or without clinical modification were encountered in 15.4% of patients and included thromboembolic complications (7.1% per procedure), intraoperative rupture (2.6% per procedure), and device-related problems (2.9% per procedure). Adverse events associated with transient or permanent neurological deficit or death were encountered in 5.4% of cases. The 1-month morbidity and mortality rates were 1.7% and 1.4%, respectively. Conclusions— Endovascular treatment of unruptured intracranial aneurysms is feasible in a high percentage of cases with low morbidity and mortality rates.