脳動脈瘤・頚動脈狭窄症に対する脳血管内治療(<特集>一般脳神経外科医が知っておくべきsubspecialtyの知識) The Basic Information of Neuroendovascular Therapy for Cerebral Aneurysms and Carotid Stenosis to the Neurosurgeons(<SPECIAL ISSUE>Knowledge of Subspecialty General Neurosurgeons should Know)

脳動脈瘤に対して行われる一般的な血管内治療は,瘤内コイル塞栓術(コイル治療)と母動脈閉塞術である.破裂脳動脈瘤に対するコイル治療の有効性は,ISATによって確認された.コイル治療に適した動脈瘤は,アプローチしやすく,neckが4mm以下,もしくはdomeの50%以下で,径が10mm以下のものとされる.10mmを超える大型動脈瘤では,高率に再開通を生じ,長期成績が良好とはいえない.部分血栓化動脈瘤の瘤内塞栓術は無効とされている.頚動脈狭窄症においては,内膜切除術(CEA)に対するステント留置術(CAS)の非劣性がSAPPHIRE試験で確認された.本邦では,CEA高危険群で症候性50%,無症候性80%以上の頚動脈狭窄症がCASの適応となる.低侵襲であるが,不安定プラークにおける末梢性塞栓症が課題である.

The standard endovascular treatment for cerebral aneurysms is endosaccular COIL embolization (coiling) and parent artery occlusion with internal trapping. The ISAT study on the treatment of ruptured aneurysms demonstrated the superiority of coiling over clipping in 2002. Small aneurysms with a small neck (4mm or less, 50% or less of dome size) and a dome of 10mm or less in size are good for coiling. Aneurysms larger than 11mm in size tend to be recanalized after long-term follow-up. Partially thrombosed aneurysms should not be treated with coils. The SAPPHIRE study proved that carotid artery stenting (CAS) in high-risk patients was not inferior to carotid endarterectomy. The treatment indication in Japan is carotid stenosis with 50% or more in symptomatic high-risk patients, and 80% or more in asymptomatic high-risk patients. CAS is a less invasive technique for carotid revascularization. Thromboembolic complications due to plaque debris, however, must be overcome.