**3.3 Endovascular treatment (EVT)**

Since its conception, endovascular treatment has rapidly taken over as the major treatment for most intracranial aneurysms. While there is supporting data for ruptured intracranial aneurysms from the ISAT trial, there is no randomized controlled trial comparing surgery and endovascular treatment to surgical clipping for unruptured aneurysms. Relative indications for endovascular treatment are poor surgical candidate, favorable aneurysm and vascular anatomy, high risk for anesthesia complications and posterior circulation aneurysms. In 2012, a systematic review and meta-analysis reported different outcomes between endovascular treatments; >52 years, >10 mm and posterior circulation location were main risk factors to poor outcomes [61]. Coiling alone was safer compared to the percent of complications reported with balloon-assisted coiling 7.1% (99% CI 3.9–12.7), 9.3% (99% CI 4.9– 16.9) with stent-assisted coiling and 11.5% (99% CI 4.9–24.6) with flow-diverting stents. However, the increase of the complications reported with additional devices can be due to the more-complex aneurysm cases or due to the number and type of devices placed. Furthermore, in the last decade the neuro-interventional procedures have improved their outcomes with increased understanding of the various treatments and technological innovation improving safety and efficacy.
