title: Assessing collateral cerebral perfusion with technetium-99m-HMPAO SPECT during temporary internal carotid artery occlusion.
abstract: Cerebral infarction following internal carotid artery occlusion results from either embolism or inadequate collateral blood flow. Although risk of embolism can be minimized, detecting compromised collateral circulation is more difficult. Cerebral angiography, carotid stump pressures and clinical evaluation during internal carotid artery occlusion are of limited utility. Xenon-133 radionuclide studies and stable xenon computed tomography are not readily available. We evaluated 99mTc-HMPAO SPECT, during temporary carotid artery occlusion, in 20 patients considered for internal carotid artery occlusion. Fourteen demonstrated symmetric cerebral perfusion during occlusion; eleven underwent transient and three had permanent carotid artery occlusion without complications. Five patients had ipsilateral globally decreased perfusion during temporary occlusion. One patient underwent transient occlusion of this vessel and one underwent carotid sacrifice without bypass grafting; both recovered without sequelae. The three remaining patients underwent carotid artery bypass grafting prior to sacrifice of this vessel. One patient with a small focal perfusion defect underwent carotid artery sacrifice without bypass grafting and developed acute neurologic deficits postoperatively. These initial results suggest that symmetric cerebral perfusion during temporary occlusion indicates that internal carotid artery occlusion will be tolerated. Although its implications are not yet well defined, the abnormal study identifies patients potentially at risk for postocclusion complications, thus providing a basis for neurosurgical management.
authors.affiliation: Division of Nuclear Medicine, Long Island Jewish Medical Center, New Hyde Park, NY 11042.
authors.forename: C J
authors.initials: CJ
authors.lastname: Palestro
authors.forename: C
authors.initials: C
authors.lastname: Sen
authors.forename: M
authors.initials: M
authors.lastname: Muzinic
authors.forename: M
authors.initials: M
authors.lastname: Afriyie
authors.forename: S J
authors.initials: SJ
authors.lastname: Goldsmith
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001157:Arterial Occlusive Diseases / Q000000981:diagnostic imaging* / Q000503:physiopathology; D001921:Brain / Q000098:blood supply* / Q000000981:diagnostic imaging; D002340:Carotid Artery Diseases / Q000000981:diagnostic imaging* / Q000503:physiopathology; D002343:Carotid Artery, Internal / Q000000981:diagnostic imaging / Q000502:physiology; D002560:Cerebrovascular Circulation / Q000502:physiology*; D003097:Collateral Circulation / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015609:Organotechnetium Compounds; D010091:Oximes; D019690:Technetium Tc 99m Exametazime; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon
chemical_list: D015609:Organotechnetium Compounds; D010091:Oximes; D019690:Technetium Tc 99m Exametazime