title: Treatment of unruptured duplicated middle cerebral artery aneurysm: case report.
abstract: BACKGROUND
  Duplication of the middle cerebral artery (DMCA) is an anomalous vessel arising from the internal carotid artery (ICA). The origin of the DMCA lies between the anterior choroidal artery and the distal end of the ICA. The association of cerebral aneurysm and DMCA is rare.
  
  
  METHODS
  In this 63-year-old woman, preoperative angiography and 3-dimensional computed tomography angiography revealed an aneurysm at the origin of the DMCA. The aneurysm was clipped and superficial temporal artery-DMCA anastomosis was performed. She was discharged with no neurologic deficits. Duplication of the middle cerebral artery can be divided into 2 types based on whether the site of separation from the ICA is at the top of the ICA (type A) or between the ICA top and the anterior choroidal artery (type B). The diameter of type A DMCA is comparable with that of the main middle cerebral artery trunk; in type B, it is smaller. In all 18 previously reported cases, the aneurysm was associated with type B DMCA.
  
  
  CONCLUSIONS
  For appropriate treatment planning, it is necessary to determine the DMCA type and the anatomic relationship between the aneurysm and the DMCA. In patients with type B DMCA, the possibility of aneurysm formation should be considered.
authors.affiliation: Department of Neurosurgery, Graduate School of Medical Science, Kumamoto University, Kumamoto 860-8556, Japan. ykai@kaiju.medic.kumamoto-u.ac.jp
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Kai
authors.forename: Jun-ichiro
authors.initials: J
authors.lastname: Hamada
authors.forename: Motohiro
authors.initials: M
authors.lastname: Morioka
authors.forename: Shigetoshi
authors.initials: S
authors.lastname: Yano
authors.forename: Mareina
authors.initials: M
authors.lastname: Kudo
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Kuratsu
mesh_terms: D000714:Anastomosis, Surgical / Q000379:methods*; D002533:Cerebral Angiography; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000601:surgery*; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000601:surgery; D019635:Neurosurgical Procedures / Q000379:methods*; D013699:Temporal Arteries / Q000000981:diagnostic imaging / Q000601:surgery; D014057:Tomography, X-Ray Computed; D014656:Vascular Surgical Procedures / Q000379:methods*