Recommendations for the endovascular treatment of intracranial aneurysms: a statement for healthcare professionals from the Committee on Cerebrovascular Imaging of the American Heart Association Council on Cardiovascular Radiology.

Intracranial aneurysms are common, with a prevalence of 0.5% to 6% in adults, according to angiography and autopsy studies.1 Most intracranial aneurysms are asymptomatic and are never detected. Some are discovered incidentally in neuroimaging studies and some produce symptoms due to compression of neighboring nerves or adjacent brain tissue. Others are detected only after they have ruptured and caused subarachnoid hemorrhage, a devastating type of stroke associated with 32% to 67% case fatality and 10% to 20% long-term dependence in survivors due to brain damage.2 To prevent subarachnoid hemorrhage, physicians have developed methods to treat aneurysms. For ruptured aneurysms, early treatment within 24 to 72 hours has been recommended because the risk of subsequent rupture is high, with approximately 20% risk of rerupture in the first 2 weeks after subarachnoid hemorrhage.3 Each additional rupture substantially increases the risk of mortality and morbidity. Treatment has also been recommended for most unruptured aneurysms,4 although there is uncertainty about treatment of some small aneurysms 10 mm because their risk of rupture appears low.5,6 The American Heart Association formed this special writing group to summarize the literature and create recommendations on endovascular therapy of ruptured and unruptured intracranial aneurysms. This statement is meant to extend previous statements on treatment of subarachnoid hemorrhage3 and on treatment of unruptured aneurysms.4 During the review, it became evident that any recommendations would be based primarily on expert opinion weighing evidence only from nonrandomized cohort studies and case series. Background In 1937, Walter Dandy reported the first successful surgical clipping of the neck of an aneurysm. Microsurgical techniques have steadily evolved since then, with development of a variety of surgical approaches and metal aneurysm clips. Repair of aneurysms in nearly all intracranial locations is possible by placing a clip made from a stable metal (including platinum, titanium, tungsten, and steel alloys) across the neck of the aneurysm, thus excluding it from the cerebral circulation. Endovascular treatment of intracranial aneurysms was first described in the early 1970s by Fedor Serbinenko, a Russian neurosurgeon.7,8 He used a vascular catheter with a detachable latex balloon to treat aneurysms, either by depositing the balloon directly into the aneurysm lumen or by occluding the artery from which the aneurysm arose. In 1991, Guido Guglielmi was the first to describe the technique of occluding aneurysms from an endovascular approach with electrolytic detachable platinum coils, termed Guglielmi detachable coils (GDCs).9,10 GDCs are introduced directly into the aneurysm through a microcatheter and detached from a stainless-steel microguidewire by an electrical current (Figure 1). The aneurysm is packed with 1 or more GDCs, thereby excluding it from the circulation (Figure 2). As clinical experience with this technique has increased and coil design has improved, coil embolization has been used with increasing frequency even in patients who could be treated by conventional surgical clipping.11,12 Furthermore, some centers are treating patients with surgical clipping only if they cannot be treated primarily by endovascular coil