A meta-analysis revealed that the mortality from coiling of a basilar bifurcation aneurysm was 0.9%, and the risk of permanent complications was 5.4%.158 More recently, with regard to treatment of posterior circula- tion aneurysms, the mortality and morbidity in 112 ruptured aneurysms was 3.7% and 9.4%, respectively.159 These data have led to an increasing tendency toward coiling ruptured posterior circulation aneurysms. One study that compared clipping versus coiling of basilar apex aneurysm (44 patients in each treatment arm) found a poor outcome rate of 11% in the endovascular treatment group versus 30% in the surgical group. In that study, the main difference was the rate of ischemia and hemorrhage during the surgical intervention. The rates of recurrent hemorrhage and delayed ischemia were actually similar in both groups.159 Incomplete aneurysm occlusion and recurrent aneurysm filling from progressive coil compaction are particularly difficult challenges encountered with endovascular treatment of basilar artery aneurysms. In a study of 41 posterior circulation aneurysms, 35 (85%) had complete or near- complete immediate angiographic occlusion. The follow-up time frame for this study was 17 months, and of the 29 patients for whom follow-up was obtained, those with com- pletely occluded aneurysms did not reveal any compaction. In the remaining patients who had near-complete occlusion, 47% had experienced recanalization, with 1 patient experi- encing a rehemorrhage.160 On the basis of these findings, closer follow-up with sequential DSA is needed in patients who undergo coiling of posterior circulation aneurysms, particularly those who do not exhibit complete occlusion on immediate follow-up angiography. Surgical and Endovascular Methods of Treatment of Ruptured Cerebral Aneurysms: Recommendations 1. Surgical clipping or endovascular coiling of the rup- tured aneurysm should be performed as early as feasible in the majority of patients to reduce the rate of rebleeding after aSAH (Class I; Level of Evidence B). 