title: Monitoring and preventing blood flow insufficiency due to clip rotation after the treatment of internal carotid artery aneurysms.
abstract: The authors report a case in which anterior choroidal artery (AChA) blood flow insufficiency due to aneurysm clip rotation was detected intraoperatively by motor evoked potential (MEP) monitoring and ischemia was successfully avoided. The patient had an incidentally discovered aneurysm for which occlusion of its neck was performed through a standard frontotemporal craniotomy without changing the MEP amplitude. After it was confirmed that the surrounding arteries were not stenotic, the brain retractor on the frontal lobe was released; MEP amplitude subsequently decreased. Rotation of the clip toward the frontal base by repositioning of the frontal lobe caused the AChA stenosis at the origin of its branches. On reorienting the clip toward the frontal lobe, the AChA stenosis was released and MEP amplitude recovered. To prevent repeated clip rotation, a large amount of gelatin (Spongel) was inserted between the frontal base and the clip. The authors confirmed that clip rotation did not occur after repositioning of the frontal lobe. Motor evoked potential amplitude was maintained until dural closure. Postoperatively, the patient demonstrated no neurological deficit and there was no newly developed low-density area on computerized tomography scans.
authors.affiliation: Department of Neurosurgery, Fukushima Medical University, Fukushima, Japan. jsakuma@fmu.ac.jp
authors.forename: Jun
authors.initials: J
authors.lastname: Sakuma
authors.forename: Kyouichi
authors.initials: K
authors.lastname: Suzuki
authors.forename: Tatsuya
authors.initials: T
authors.lastname: Sasaki
authors.forename: Masato
authors.initials: M
authors.lastname: Matsumoto
authors.forename: Masahiro
authors.initials: M
authors.lastname: Oinuma
authors.forename: Masahisa
authors.initials: M
authors.lastname: Kawakami
authors.forename: Takeshi
authors.initials: T
authors.lastname: Itakura
authors.forename: Namio
authors.initials: N
authors.lastname: Kodama
mesh_terms: D000328:Adult; D002545:Brain Ischemia / Q000175:diagnosis / Q000601:surgery*; D002340:Carotid Artery Diseases / Q000175:diagnosis / Q000601:surgery*; D002343:Carotid Artery, Internal / Q000473:pathology / Q000601:surgery*; D002483:Cellulose, Oxidized; D002831:Choroid Plexus / Q000098:blood supply*; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D005625:Frontal Lobe / Q000473:pathology / Q000601:surgery; D006801:Humans; D002532:Intracranial Aneurysm / Q000175:diagnosis / Q000601:surgery*; D007431:Intraoperative Complications / Q000175:diagnosis / Q000601:surgery*; D016343:Monitoring, Intraoperative; D013525:Surgical Instruments
chemical_list: D002483:Cellulose, Oxidized; C013695:Surgicel