Endovascular treatment has been an important treatment modality for ruptured aneurysms. International Subarachnoid Aneurysm Trial (ISAT) has shown that endovascular coiling of ruptured aneurysm had lower mortality and disability at 1 year compared with microsurgical clipping (23.5% vs 30.9%) [
15]. The Barrow Ruptured Aneurysm Trial has shown that endovascular coiling resulted in fewer unfavorable outcomes when comparing the safety of clipping and coiling for ruptured aneurysms [
16]. However, the endovascular coiling of ruptured wide-necked aneurysms remains challenging because of the probability of the coil protruding into the parent artery causing serious complications.
SAC alters hemodynamics characters of parent artery and aneurysms and contributes to thrombosis in the aneurysms to decrease the risk of recurrence of aneurysms [
5,
7]. Several previous studies have shown the safety and efficacy of SAC for ruptured aneurysms [
5,
7,
17,
18]. However, most studies involved a wide range of time intervals after the onset of hemorrhage. Although SAC of acutely ruptured cerebral aneurysms is feasible, the sizes of samples were relatively small in retrospective studies [
4,
19‐
21]. A single-center retrospective study that reported the safety and efficacy of SAC of ruptured cerebral aneurysms (no more than 28 days of hemorrhage) has shown that the rates of periprocedural complications and mortality in SAC group did not differ from those of non-SAC group (overall perioperative complications: 8.3% vs 4.5%,
P = 0.120; mortality:1.5% vs 0.7%,
P = 0.796), which accompanied with a higher occlusion rate and lower recurrence rate in SAC group (82.5% vs 66.7, 3.5% vs 14.5%,
p = 0.007) [
22]. Meanwhile, Xue et al [
23] conducted a retrospective study on the safety and efficacy of LVIS-assisted coiling of acutely ruptured wide-necked intracranial aneurysms (no more than 28 days) compared with a single coiling strategy, which showed a similar result of perioperative complications of 7.6%. A current systematic review enrolling 399 patients who received SAC of a ruptured cerebral aneurysm (less than 7 days after onset) reported approximately 12% of overall perioperative complications [
14]. Nevertheless, a meta-analysis including 499 patients with ruptured cerebral aneurysms who underwent SAC has shown that the rate of adverse events was approximately 20.2% [
24].
The evidence of SAC of acutely ruptured cerebral aneurysm is lacking. Meanwhile, there is no prospective multicenter study regarding the genuinely acutely ruptured aneurysms defined as within 72 hours after the onset of the syndrome. The safety and efficiency of SAC of acutely ruptured cerebral aneurysms require further prospective study. Many detailed questions including the optimal time for early treatment, the appropriate regimen of antiplatelet therapy, and risk factors for perioperative complications remain unknown [
25‐
27]. In this study, we will perform a prospective, multicenter, and observational registry study of consecutive patients with wide-neck acutely ruptured cerebral aneurysms to improve the safety strategy of SAC of acutely ruptured cerebral aneurysms.