title: Microneurosurgical management of middle cerebral artery bifurcation aneurysms.
abstract: BACKGROUND
  Of the MCA aneurysms, those located at the main bifurcation of the MCA (MbifA) are by far the most frequent. The purpose of this article is to review the practical anatomy, preoperative planning, and avoidance of complications in the microsurgical dissection and clipping of MbifAs.
  
  
  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 patient selection the catchment area in southern and eastern Finland.
  
  
  RESULTS
  These 2 centers have treated more than 10,000 patients with intracranial aneurysm's since 1951. In the Kuopio Cerebral Aneurysm Data Base of 3005 patients with 4253 aneurysms, MbifAs formed 30% of all ruptured aneurysms, 36% of all unruptured aneurysms, 35% of all giant aneurysms, and 89% of all MCA aneurysms. Importantly, in 45%, rupture of MbifA caused an ICH.
  
  
  CONCLUSIONS
  Middle cerebral artery bifurcation aneurysms are often broad necked and may involve one or both branches of the bifurcation (M2s). The anatomical and hemodynamic features of MbifAs make them usually more favorable for microneurosurgical treatment. In population-based services, MbifAs are frequent targets of elective surgery (unruptured), acute surgery (ruptured), and emergency surgery (large ICH), even advanced approaches (giant). The challenge is to clip the neck adequately, without neck remnants, while preserving the bifurcational flow.
authors: Department of Neurosurgery, Helsinki University Central Hospital, 00260 Helsinki, Finland.
authors: Reza
authors: R
authors: Dashti
authors: Juha
authors: J
authors: Hernesniemi
authors: Mika
authors: M
authors: Niemelä
authors: Jaakko
authors: J
authors: Rinne
authors: Matti
authors: M
authors: Porras
authors: Martin
authors: M
authors: Lehecka
authors: Hu
authors: H
authors: Shen
authors: Baki S
authors: BS
authors: Albayrak
authors: Hanna
authors: H
authors: Lehto
authors: Päivi
authors: P
authors: Koroknay-Pál
authors: Rafael Sillero
authors: RS
authors: de Oliveira
authors: Giancarlo
authors: G
authors: Perra
authors: Antti
authors: A
authors: Ronkainen
authors: Timo
authors: T
authors: Koivisto
authors: Juha E
authors: JE
authors: Jääskeläinen
mesh_terms: D002533:Cerebral Angiography / Q000379:methods / Q000592:standards; D002560:Cerebrovascular Circulation / Q000502:physiology; D006801:Humans; D002532:Intracranial Aneurysm / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D007431:Intraoperative Complications / Q000209:etiology / Q000517:prevention & control; D020768:Middle Cerebral Artery / Q000000981:diagnostic imaging / Q000473:pathology / Q000601:surgery*; D019635:Neurosurgical Procedures / Q000295:instrumentation / Q000379:methods* / Q000592:standards; D011300:Preoperative Care / Q000592:standards; D013525:Surgical Instruments / Q000592:standards; D014656:Vascular Surgical Procedures / Q000295:instrumentation / Q000379:methods* / Q000592:standards