Emergency superficial temporal artery–superior cerebellar artery bypass for hyperacute basilar artery occlusion following elective middle cerebral artery aneurysm clipping: illustrative case

A 69-year-old man with a recent history of bilateral cerebellar infarction underwent elective microsurgical clipping of a left M1 middle cerebral artery aneurysm. The authors confirmed complete aneurysm exclusion with postoperative CTA. Eight hours later, the patient developed aphasia and deep state coma. CTA perfusion revealed BAO, with extensive cerebellar penumbra and a small core. Due to severe preexisting right vertebral and basilar intracranial atherosclerotic disease, urgent STA-SCA bypass was performed with a right subtemporal approach. Intraoperative studies confirmed graft patency reperfusion. The patient recovered consciousness and was discharged with a modified Rankin Scale score of 3. https://thejns.org/doi/10.3171/CASE25710.