Blood Blister-like Aneurysm Treated with Coil Embolization without Stent Assistance

We report a case of blood blister-like aneurysm treated with coil embolization without stent assistance. A 34-year-old man with a medical history of hypertension presented with subarachnoid hemorrhage. Initial digital subtraction and computed tomography angiography did not demonstrate definite vascular pathologies. Two weeks later, follow-up angiography showed a wide neck aneurysm on the dorsal wall of left distal internal carotid artery, which was not found on the first angiograms. This blood blister-like aneurysm was successfully treated with coil embolization without stent assistance, and the regrowth or recanalization has not been identified for 6 months. While both surgical and endovascular procedures are quite challenging, endovascular coiling with stent assistance for this aneurysm is generally recommended. But endovascular coiling without stent assistance may be attempted for instances such as relatively narrow neck and young age.