Improved safety of intracranial aneurysm coiling with OPTIMA™: Results of the INSTANT study

BACKGROUND AND PURPOSE: Coiling remains a widely used, first-line endovascular treatment for intracranial aneurysms. However, recent large-scale evaluations are limited since the ARETA study, which assessed the safety and efficacy of aneurysm coiling in patients treated between 2013 - 2015. A detailed analysis of the INSTANT study is presented, which provides recent data on endovascular treatment of intracranial aneurysms with the OPTIMA™ coil system (Balt). MATERIALS AND METHODS: INSTANT is a European, non-interventional, prospective study that assessed patients with ruptured, unruptured, or recanalized aneurysms treated with OPTIMA™. The primary endpoint was the morbi-mortality of patients treated with OPTIMA™ at 30 days, with an additional assessment at 12 months as a secondary endpoint. RESULTS: From April 2019 to September 2022, 294 patients (56.3±12.0 years, 186 women [63.3%]) were enrolled in 18 European centers. Aneurysms were acutely ruptured in 45.2% of cases (N=133/294) and unruptured/recanalized in 54.8% (N=161/294). The overall mortality at 30 days was 0.0% in patients with unruptured aneurysms and 3.0% (N=4/133, [95% CI:0.1-5.9]) in those with ruptured aneurysms, which were all related to SAH and its complications. Overall, morbidity at 30 days was 1.2% (N=2/161, [95% CI:0.0-3.0]) in patients with unruptured aneurysms and 21.1% (N=28/133, [95% CI:14.1-28.0]) in patients with ruptured aneurysms. No deaths or adverse events resulting in morbidity were related to OPTIMA™ or the procedure (0.0%). CONCLUSIONS: In the INSTANT study, treatment of intracranial aneurysms with the OPTIMA™ coil system showed low morbidity and mortality at 30 days and 12 months, unrelated to the device or procedure.