The ISAT study (International Subarachnoid Aneurysm Trial) was published in 2002[^1]. The ISAT study was a randomized, multicenter study in which, based on 2143 patients, it was demonstrated that in patients with a ruptured aneurysm, endovascular treatment of the Aneurysms resulted in significantly better survival free of disability compared with surgical clipping. The survival benefit continued to be present in the endovascular group after 7 years[^2]. The risk of recurrent subarachnoid hemorrhage was very low in both groups, but was overall higher in the group of patients who underwent endovascular treatment[^1] [^2].
Authors' conclusion
In patients with a ruptured intracranial aneurysm, for which endovascular coiling and neurosurgical clipping are therapeutic options, the outcome in terms of survival free of disability at 1 year is significantly better with endovascular coiling. The data available to date suggest that the long-term risks of further bleeding from the treated aneurysm are low with either therapy, although somewhat more frequent with endovascular coiling[^1].
In patients with ruptured intracranial aneurysms suitable for both treatments, endovascular coiling is more likely to result in independent survival at 1 year than neurosurgical clipping; the survival benefit continues for at least 7 years. The risk of late rebleeding is low, but is more common after endovascular coiling than after neurosurgical clipping[^2].