title: Microneurosurgical management of proximal middle cerebral artery aneurysms.
abstract: BACKGROUND
  The M1As are located in the main trunk (M1) of the MCA, between the bifurcation of the ICA and the main bifurcation of M1. Proximal MCA aneurysms are often small and thin-walled, which makes their proper clipping tedious. There are few reports on their microsurgery.
  
  
  METHODS
  This review, and the whole series on intracranial aneurysms, is mainly based on the personal microneurosurgical experience of the senior author (JH) in 2 Finnish centers (Helsinki and Kuopio), which serve, without selection, the catchment area in the southern and eastern Finland.
  
  
  RESULTS
  These 2 centers have treated more than 10000 patients with aneurysm since 1953. We review the practical anatomy, preoperative planning, and avoidance of complications in the microsurgical dissection and clipping of M1As which form 7.4% of all intracranial and 14% of all MCA aneurysms in our patients.
  
  
  CONCLUSIONS
  Proximal MCA aneurysms are often wide-necked and intimately connected to an M1 branch at its origin on M1, features that favor exosurgery rather than endosurgery. The direction and course of the parent and branching arteries and the orientation of the fundus are the most important factors affecting the efficacy and safety of clipping.
authors.affiliation: Department of Neurosurgery, Helsinki University Central Hospital, 00260 Helsinki, Finland.
authors.forename: Reza
authors.initials: R
authors.lastname: Dashti
authors.forename: Jaakko
authors.initials: J
authors.lastname: Rinne
authors.forename: Juha
authors.initials: J
authors.lastname: Hernesniemi
authors.forename: Mika
authors.initials: M
authors.lastname: Niemelä
authors.forename: Leena
authors.initials: L
authors.lastname: Kivipelto
authors.forename: Martin
authors.initials: M
authors.lastname: Lehecka
authors.forename: Ayse
authors.initials: A
authors.lastname: Karatas
authors.forename: Emel
authors.initials: E
authors.lastname: Avci
authors.forename: Keisuke
authors.initials: K
authors.lastname: Ishii
authors.forename: Hu
authors.initials: H
authors.lastname: Shen
authors.forename: José G
authors.initials: JG
authors.lastname: Peláez
authors.forename: Baki S
authors.initials: BS
authors.lastname: Albayrak
authors.forename: Antti
authors.initials: A
authors.lastname: Ronkainen
authors.forename: Timo
authors.initials: T
authors.lastname: Koivisto
authors.forename: Juha E
authors.initials: JE
authors.lastname: Jääskeläinen
mesh_terms: D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000601:surgery*; D008866:Microsurgery / Q000379:methods*; D019635:Neurosurgical Procedures / Q000379:methods*; D011859:Radiography