Although the quality of the data is modest, most agree that with current endovascular technol- ogy, middle cerebral artery aneurysms can be difficult to treat with coil embolization, and in this location, surgical treatment has tended to yield more favorable results.146,150 152 Although some have suggested that older patients are ideal candidates for coiling rather than clipping, data on this population are sparse and at times conflicting.141,153,154 Although patients presenting with an intraparenchymal hematoma 50 mL have a higher incidence of unfavorable outcome, hematoma evacuation within 3.5 hours has been shown to improve outcome in this subgroup and argues in favor of microsurgery for most patients with large parenchymal clots.155 By con- trast, patients presenting during the vasospasm period, espe- cially those with confirmed vasospasm, may be better treated with endovascular techniques, depending on the anatomy of the aneurysm and its relationship to the spasm.150 Patients presenting with poor clinical grade appear to benefit more from endovascular coiling, especially if they are also elderly, because advanced age renders long-term durability less important.156 Still, it is critical that patients with poor clinical grade be treated in centers where both modalities are available.157 Endovascular treatment of posterior circulation aneurysms has been gaining widespread acceptance based on several observational studies. 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. 