title: Microneurosurgical management of distal middle cerebral artery aneurysms.
abstract: BACKGROUND
  Distal middle cerebral artery aneurysms originate from branches of MCA distal to its main bifurcation or the peripheral branches. Distal middle cerebral artery aneurysms are the least frequently seen among the middle cerebral artery aneurysms. The purpose of this article is to review the practical anatomy, preoperative planning, and avoidance of complications in the microsurgical dissection and clipping of MdistAs.
  
  
  METHODS
  This review, and the whole series on intracranial aneurysms, are 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 10000 aneurysm patients since 1951. In the Kuopio Cerebral Aneurysm Database of 3005 patients with 4253 aneurysms, 69 patients carrying altogether 78 MdistAs formed 5% of all MCA aneurysms. Among the 18 patients with ruptured MdistAs (23%), an ICH occurred in 9 (50%).
  
  
  CONCLUSIONS
  Distal middle cerebral artery aneurysms are rare. The microneurosurgical treatment of MdistAs is challenging. They are often difficult to localize during the operation, and lack of collateral circulation makes their occlusion more demanding. High rate of ICH and high tendency of rebleeding urge acute or emergency surgery in most of ruptured cases. Microneurosurgical clipping is the most effective treatment of MdistAs.
authors.affiliation: Department of Neurosurgery, Helsinki University Central Hospital, Helsinki 00260, Finland.
authors.forename: Reza
authors.initials: R
authors.lastname: Dashti
authors.forename: Juha
authors.initials: J
authors.lastname: Hernesniemi
authors.forename: Mika
authors.initials: M
authors.lastname: Niemelä
authors.forename: Jaakko
authors.initials: J
authors.lastname: Rinne
authors.forename: Martin
authors.initials: M
authors.lastname: Lehecka
authors.forename: Hu
authors.initials: H
authors.lastname: Shen
authors.forename: Hanna
authors.initials: H
authors.lastname: Lehto
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: D000208:Acute Disease; D017542:Aneurysm, Ruptured / Q000150:complications / Q000453:epidemiology / Q000601:surgery; D015901:Angiography, Digital Subtraction / Q000379:methods; D006285:Health Planning / Q000379:methods; D046648:Hematoma, Subdural, Intracranial / Q000453:epidemiology / Q000601:surgery; D006801:Humans; D006849:Hydrocephalus / Q000453:epidemiology / Q000601:surgery; D002532:Intracranial Aneurysm / Q000150:complications / Q000453:epidemiology / Q000601:surgery*; D008866:Microsurgery / Q000379:methods*; D020768:Middle Cerebral Artery / Q000033:anatomy & histology; D019635:Neurosurgical Procedures / Q000379:methods*; D011183:Postoperative Complications / Q000517:prevention & control; D011300:Preoperative Care; D013345:Subarachnoid Hemorrhage / Q000209:etiology / Q000601:surgery