title: Paraclinoid aneurysms of the internal carotid artery: hydraulic simulation study on their locations and shape of the carotid siphon.
abstract: Hemodynamics of paraclinoid aneurysms were investigated focusing on the effects of their locations and shape of the carotid siphon. A transparent silicon model of the carotid siphon was constructed and a model aneurysm was attached to the outside of the curvature at three different sites. Glycerol solution was perfused into the model, and the half-life of the dye injected into the aneurysm was calculated as an index of the stagnant flow. Values of half-life changed significantly depending on the aneurysmal location and the siphon angle. When the siphon angle was 0 degree where C2 and C4 segments were parallel to each other, the half-life value was the lowest in the C2-C3 junction aneurysm, highest in the C3 segment aneurysm and intermediate in the C2 segment aneurysm. While the C2-C3 junction aneurysm maintained low values regardless of the angle, the C3 segment aneurysm values decreased and C2 segment aneurysm values increased with increases in the angle. These changes of half-life occur because the point at which the faster moving fluid component strikes the curved wall changes according to the siphon angle. These results are considered useful to determine the surgical indications, treatment modalities and post-surgical management of the aneurysms.
authors.affiliation: Department of Neurosurgery, Osaka Medical College, Takatsuki, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Yamaguchi
authors.forename: S
authors.initials: S
authors.lastname: Nagasawa
authors.forename: S
authors.initials: S
authors.lastname: Kawabata
authors.forename: M
authors.initials: M
authors.lastname: Kawanishi
authors.forename: Y
authors.initials: Y
authors.lastname: Tada
authors.forename: T
authors.initials: T
authors.lastname: Ohta
mesh_terms: D000328:Adult; D000783:Aneurysm / Q000473:pathology / Q000503:physiopathology*; D001783:Blood Flow Velocity / Q000502:physiology; D002340:Carotid Artery Diseases / Q000473:pathology / Q000503:physiopathology*; D002343:Carotid Artery, Internal / Q000473:pathology / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000502:physiology*; D004867:Equipment Design; D006801:Humans; D008955:Models, Cardiovascular