Endovascular treatment of a blister-like aneurysm of the internal carotid artery.

BACKGROUND: Blister-like aneurysms of the supraclinoid internal carotid artery have recently been recognized as having unique pathological and clinical features. Little is known regarding their optimal treatment modality. METHODS: We report a case of a blister-like aneurysm of the internal carotid artery treated with Guglielmi detachable coil (GDC) embolization. CASE REPORT: A 55-year-old man presented with a Hunt & Hess grade II subarachnoid hemorrhage. Computed tomography revealed diffuse subarachnoid blood. Cerebral angiography demonstrated a broad-based bulge on the medial wall of the right distal internal carotid artery. The patient was taken to the operating room and underwent a right pterional craniotomy and wrapping of this unclippable aneurysm. On postoperative day 11, he developed signs of vasospasm, and repeat angiography showed remarkable growth of the aneurysm. The aneurysm was believed to be amenable to endovascular therapy and was treated by GDC embolization. The patient recovered well and remained neurologically intact on follow-up examinations. Repeat cerebral angiography was performed three and nine months following his initial presentation and revealed a significant aneurysm neck remnant. This neck remnant was treated by repeat GDC embolization 13 months following his subarachnoid hemorrhage. CONCLUSIONS: Blister-like aneurysms of the internal carotid artery are important to recognize and are difficult to manage using traditional surgical approaches. Early repeated cerebral angiography is indicated and, where appropriate, endovascular therapy should be considered in the management of these patients