Endovascular Coiling for a Ruptured Middle Cerebral Artery-lenticulostriate Artery Bifurcation Aneurysm Suspected to Be a Pseudoaneurysm: A Case Report

Intracranial pseudoaneurysm is a rare entity. Pseudoaneurysm can change its shape dynamically, and the optimal treatment must be selected on the basis of the individual situation. Due to the fragility of the pseudoaneurysm wall, surgical intervention can be difficult. Moreover, a middle cerebral artery-lenticulostriate artery bifurcation aneurysm is uncommon. Surgical intervention carries a risk of ischemic complications in perforating branches. We treated a 43-year-old woman with cardiopulmonary arrest due to a subarachnoid hemorrhage. A right middle cerebral artery-lenticulostriate artery bifurcation aneurysm was detected, which was suspected to be a pseudoaneurysm. The aneurysmal shape changed dynamically, probably because of thrombus formation and resolution. Delayed cerebral vasospasm was also observed. A simple coil embolization was performed initially on day 13 after onset, but early recanalization was observed on day 26, and a second coil embolization was carried out with good obliteration on day 34. The patient subsequently had mild left hemiparesis and mild cognitive dysfunction. After 4 months of rehabilitation, the hemiparesis resolved. Angiography 6 months after onset showed that good obliteration was maintained. For this rare complex condition of a pseudoaneurysm and middle cerebral artery-lenticulostriate artery bifurcation aneurysm, tailored endovascular treatment may be a feasible option.