Ruptured hidden intracranial aneurysm during mechanical thrombectomy: A case report

BACKGROUND: Acute ischemic stroke (AIS) patients have a higher prevalence of cerebral aneurysm than a healthy reference population. However, it was recently reported that cases of an unknown hidden aneurysm in AIS patients with large-vessel occlusion are rare. We report a rare case of subarachnoid hemorrhage (SAH) during mechanical thrombectomy (MT) using a stent retriever for AIS. CASE DESCRIPTION: A 46-year-old patient with the right internal carotid artery terminal occlusion presented with the left-sided hemiparesis, hemispatial neglect, and dysarthria and underwent MT. Initial thrombectomy using a stent retriever and reperfusion catheter was unsuccessful. Angiography just before the second attempt showed SAH. Fortunately, we achieved recanalization of the thrombolysis in cerebral infarction 2b and hemostasis by lowering the blood pressure followed by coil embolization of the ruptured aneurysm. Only a few cases of ruptured aneurysms have been reported during MT using a stent retriever. Stent withdrawal is suspected to cause aneurysm rupture in cases with an unknown hidden middle cerebral artery bifurcation aneurysm. CONCLUSION: Preinterventional detection of a hidden aneurysm is difficult. Therefore, surgeons must always consider the possibility of a hidden aneurysm rupture in vessels distal to the occlusion site and make adequate preparations for the prompt treatment of ruptured aneurysms after MT.