Introduction Coiling is still the first-line endovascular treatment for the management of intracranial aneurysms. This treatment was not evaluated in recent, large series. ARETA study has evaluated the safety and efficacy of aneurysm coiling but the recruitment took place roughly 10 years ago (2013/2015).

Aim of Study The European study INSTANT is evaluating endovascular treatment of intracranial aneurysms with OPTIMA coils (Balt, Montmorency, France).

Methods INSTANT study included patients with ruptured, unruptured, or recanalized aneurysms treated with OPTIMA coils. The primary endpoint was evaluation of safety (morbidity and mortality at one-month). Several secondary endpoints were further evaluating safety and efficacy. All adverse events and anatomical results were independently evaluated.

Results The study population for this analysis consisted of 294 patients (56.3 ± 12.0 years, 186 women, [63.3%]) included in 18 European centers during the period ( 04/2019 – 04/2022). Aneurysms were sacciform in all patients, ruptured in 133/294 patients (45.2%) and unruptured or recanalized in 161/294 patients (54.8%). Aneurysm location was anterior communicating artery in 126/294 patients (42.9%), middle cerebral artery in 52/294 (17.7%), carotid siphon in 95/294 patients (32.3%) and vertebrobasilar system in 21/294 (7.1%).

Mortality at 1-month was 0.0% in patients with unruptured aneurysms and 3.0% in those with ruptured aneurysms, all related to subarachnoid hemorrhage and its complications. Morbidity at 1-month was 1.2% in patients with unruptured aneurysms and 21.1% in those with ruptured aneurysms.

Conclusion INSTANT study provides a recent evaluation of safety and efficacy of coiling in the management of ruptured and unruptured/recanalized aneurysms.

Disclosure of Interest Laurent Pierot is consultant for Balt.

Other authors have nothing to disclose.