Ruptured saccular aneurysm of the lenticulostriate artery embolized without parent artery occlusion in a case of moyamoya disease

In cases of moyamoya disease, an aneurysm of the lenticulostriate artery (LSA) is a rare finding. Preventive management of rebleeding from a ruptured aneurysm of the LSA is important to avoid poor outcomes. Endovascular embolization of a ruptured LSA aneurysm with parent artery occlusion has been reported in previous cases of moyamoya disease; however, to the best of our knowledge, a ruptured aneurysm treated only with coil embolization has not been described. A 42-year-old woman presented with sudden onset of dysarthria and right hemiparesis. Putaminal hemorrhage from a ruptured aneurysm in the left LSA was detected. Angiographically, moyamoya vessels were revealed. The aneurysm in the left LSA was saccular type and seemed to be related to moyamoya disease. As the aneurysm was successfully approached with a microcatheter, coil embolization without parent artery occlusion was performed. Rebleeding from the embolized aneurysm in the LSA did not occur. This is the first report of a ruptured LSA aneurysm embolized using coils through a flow-guiding microcatheter without parent artery occlusion in a case of moyamoya disease.