[Internal coil trapping for a doughnut-shaped giant intracranial aneurysm: a case report].

We present the case of a 65-year-old woman with a doughnut-shaped giant intracranial aneurysm that was treated using endovascular internal coil trapping. She presented with a history of headache. Magnetic resonance imaging and cerebral angiography showed a doughnut-shaped giant intracranial aneurysm in the intracavernous portion of the internal cerebral artery. A microcatheter was placed distal to the internal cerebral artery, along the wall of the aneurysm. The aneurysm was then occluded by internal coil trapping without bypass surgery, because the outcome of the balloon occlusion test was acceptable. The aneurysm was completely obliterated without causing permanent neurological deficits.