Intraoperative idiopathic subarachnoid hemorrhage during carotid artery stenting: A case report and literature review.

Carotid artery stenting (CAS) has a fatal complication of intracranial hemorrhage (ICH) associated with cerebral hyperperfusion syndrome (CHS), i.e. brain hemorrhage and subarachnoid hemorrhage (SAH). Although SAH accounts for a small percentage of these patients, it is difficult to make a differential diagnosis of this syndrome from CHS without ICH because the clinical presentations resemble each other. Furthermore, not only does the cause of SAH following CAS remain unclear but also the role of controlling postoperative blood pressure is not detected in preventing ICH after CAS. Herein, we report a case of SAH following CAS and review previous literature to discuss the mechanism and the management of this fatal complication. A 78-year-old woman with a history of arteriosclerotic obliteration and myocardial infarction was referred to our department for intervention to asymptomatic severe stenosis of the right internal carotid artery. We performed CAS under local anesthesia. Although her blood pressure was controlled to normotension during the procedure, the patient complained of headache following predilation. Postoperative emergent non-contrast computed tomography revealed SAH with leakage of contrast medium occupying the right sylvian fissure. We continued strict blood pressure control, and the patient was discharged without any neurological deficit. A well-opened lumen of the stent was recognized three months later at the outpatient visit. Strict control of intraoperative and postoperative blood pressure may improve the outcome of SAH following CAS though the role in preventing ICH after CAS is unclear.