title: Preoperative visualization of the marginal tentorial artery as an unusual collateral pathway in a patient with symptomatic bilateral vertebral artery occlusion undergoing arterial bypass surgery: A 7.0-T magnetic resonance imaging study.
abstract: BACKGROUND
  Extracranial-intracranial arterial bypass surgery is rarely performed for recurrent or progressing stroke due to vertebrobasilar artery steno-occlusive disease. Non-enhanced 7.0-T magnetic resonance (MR) imaging reveals cerebral arteries more clearly than 3.0-T or less MR imaging.
  
  
  METHODS
  A 45-year-old man developed recurrent transient ischemic attacks due to hemodynamic ischemia caused by occlusion of bilateral vertebral arteries despite antiplatelet therapy. MR angiography with a 7.0-T imager demonstrated that each marginal tentorial artery ran along the tentorial edge and anastomosed with each posterior cerebral artery (PCA) as collateral circulation. Superficial temporal artery (STA)-superior cerebellar artery (SCA) or PCA bypass surgery was planned through a subtemporal approach. During surgery, the SCA was not visible when the tentorial edge was elevated. The tentorium was not cut, and the STA was anastomosed with the P2 segment of the PCA. Ischemic symptoms completely resolved after surgery.
  
  
  CONCLUSIONS
  Preoperative 7.0-T MR imaging visualized the marginal tentorial artery as an unusual collateral pathway in a patient with symptomatic bilateral vertebral artery occlusion undergoing arterial bypass surgery.
authors.affiliation: Department of Neurosurgery, Iwate Medical University, Morioka, Iwate, Japan.
authors.forename: Yuiko
authors.initials: Y
authors.lastname: Sato
authors.affiliation: Department of Neurosurgery, Iwate Medical University, Morioka, Iwate, Japan.
authors.forename: Kuniaki
authors.initials: K
authors.lastname: Ogasawara
authors.affiliation: Department of Neurosurgery, Iwate Medical University, Morioka, Iwate, Japan.
authors.forename: Kenji
authors.initials: K
authors.lastname: Yoshida
authors.affiliation: Division of Ultra-High Field MRI and Department of Radiology, Iwate Medical University, Morioka, Iwate, Japan.
authors.forename: Makoto
authors.initials: M
authors.lastname: Sasaki
keywords: 7.0-T MR imaging; arterial bypass surgery; collateral circulation; vertebral artery occlusion