Subarachnoid hemorrhage associated with cerebral hyperperfusion syndrome after simultaneous carotid endarterectomy and coronary artery bypass grafting procedures: A case report and review of the literature

Background: Intracranial hemorrhage associated with cerebral hyperperfusion syndrome (CHS) is a potentially devastating complication of carotid endarterectomy (CEA) or carotid artery stenting. Intracranial hemorrhage can comprise of intracerebral hemorrhage or subarachnoid hemorrhage (SAH), but SAH after CEA is rare. We report a case of SAH associated with CHS that followed simultaneous CEA and coronary artery bypass grafting (CABG). Case description: A 78-year-old man developed left-sided hemiparesis and was admitted to our institution. A preoperative study showed severe stenosis of the right carotid artery associated with markedly reduced cerebral blood flow (CBF), and a CEA was scheduled after initiating medical treatment. However, the patient developed unstable angina requiring an emergency CABG before undergoing an elective CEA. Given the risk of stroke associated with performing CABG alone, simultaneous CEA and CABG were urgently performed. The patient received dual antiplatelet therapy preoperatively and anticoagulation intraoperatively for the CABG procedure, and the anticoagulation was continued postoperatively due to the development of atrial fibrillation. Three days after the surgery, the patient developed a headache and magnetic resonance imaging demonstrated right-sided cortical SAH. Single-photon emission computed tomography revealed a significantly increased CBF. Therefore, the SAH appears to have been associated with CHS after the CEA. The hemorrhage was managed conservatively and resolved without an associated neurological deficit. Conclusion: SAH after CEA is rare clinical manifestation of CHS. Simultaneous CEA and CABG, or aggressive perioperative antithrombotic therapy, may increase the risk of its occurrence. Early diagnosis and careful management are important for favorable outcomes