title: Surgical Strategy for Complex Anterior Cerebral Artery Aneurysms: Retrospective Case Series and Literature Review.
abstract: OBJECTIVE
  Giant, or complex, aneurysms of the anterior cerebral artery (ACA) are rare, but their surgical treatment is important. The authors describe their experiences with bypasses for complex ACA aneurysms and discuss the new classification of ACA bypasses, the concept of using bypasses for insurance during the approach to the aneurysm, and simplifying the surgical algorithms for these complex ACA aneurysms.
  
  
  METHODS
  Over a 19-year period, 7 cases of complex ACA aneurysm were treated with bypasses and reviewed retrospectively. The bypasses were classified into 4 groups according to donor blood flow: internal carotid artery-ACA, external carotid artery-ACA, communicating bypass, and reconstruction bypass of the ipsilateral postcommunicating ACA.
  
  
  RESULTS
  The cases included 1 precommunicating aneurysm, 3 communicating aneurysms, 2 postcommunicating aneurysms, and 1 double aneurysm (communicating and postcommunicating). The types of bypass included 1 internal carotid artery-ACA, 6 communicating bypasses, 3 external carotid artery-ACAs, and 2 reconstruction bypass of the postcommunicating ACA. Postoperative modified Rankin Scale scores were 0 (6 cases) and 3 (1 case of a communicating aneurysm with complicated memory disturbance because of infarction). One case revealed asymptomatic infarction.
  
  
  CONCLUSIONS
  Surgical treatment of complex ACA aneurysms requires knowledge of a variety of bypass techniques. Although the type of bypass should be selected according to patient-specific anatomy and the neurosurgeon's preference, the new classification of bypass-specified ACA aneurysms may alter the way surgeons think about ACA bypasses, and in combination with the concept of the protective bypass, can be used to establish a comprehensive algorithm for each type of complex ACA aneurysm.
authors.affiliation: Stroke Center, Department of Neurosurgery, Teishinkai Hospital, Hokkaido, Japan. Electronic address: nakao1980@gmail.com.
authors.forename: Nakao
authors.initials: N
authors.lastname: Ota
authors.affiliation: Stroke Center, Department of Neurosurgery, Teishinkai Hospital, Hokkaido, Japan.
authors.forename: Rokuya
authors.initials: R
authors.lastname: Tanikawa
authors.affiliation: Stroke Center, Department of Neurosurgery, Teishinkai Hospital, Hokkaido, Japan.
authors.forename: Masataka
authors.initials: M
authors.lastname: Miyama
authors.affiliation: Stroke Center, Department of Neurosurgery, Teishinkai Hospital, Hokkaido, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Matsumoto
authors.affiliation: Stroke Center, Department of Neurosurgery, Teishinkai Hospital, Hokkaido, Japan.
authors.forename: Takanori
authors.initials: T
authors.lastname: Miyazaki
authors.affiliation: Stroke Center, Department of Neurosurgery, Teishinkai Hospital, Hokkaido, Japan.
authors.forename: Hidetoshi
authors.initials: H
authors.lastname: Matsukawa
authors.affiliation: Stroke Center, Department of Neurosurgery, Teishinkai Hospital, Hokkaido, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Yanagisawa
authors.affiliation: Stroke Center, Department of Neurosurgery, Teishinkai Hospital, Hokkaido, Japan.
authors.forename: Go
authors.initials: G
authors.lastname: Suzuki
authors.affiliation: Stroke Center, Department of Neurosurgery, Teishinkai Hospital, Hokkaido, Japan.
authors.forename: Shiro
authors.initials: S
authors.lastname: Miyata
authors.affiliation: Stroke Center, Department of Neurosurgery, Teishinkai Hospital, Hokkaido, Japan.
authors.forename: Kosumo
authors.initials: K
authors.lastname: Noda
authors.affiliation: Stroke Center, Department of Neurosurgery, Teishinkai Hospital, Hokkaido, Japan.
authors.forename: Toshiyuki
authors.initials: T
authors.lastname: Tsuboi
authors.affiliation: Stroke Center, Department of Neurosurgery, Teishinkai Hospital, Hokkaido, Japan.
authors.forename: Rihei
authors.initials: R
authors.lastname: Takeda
authors.affiliation: Stroke Center, Department of Neurosurgery, Teishinkai Hospital, Hokkaido, Japan.
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Kamiyama
authors.affiliation: Stroke Center, Department of Neurosurgery, Teishinkai Hospital, Hokkaido, Japan.
authors.forename: Sadahisa
authors.initials: S
authors.lastname: Tokuda
mesh_terms: D000328:Adult; D000368:Aged; D020771:Anterior Cerebral Artery / Q000601:surgery*; D002342:Carotid Artery, External / Q000473:pathology / Q000601:surgery; D002343:Carotid Artery, Internal / Q000473:pathology / Q000601:surgery; D002544:Cerebral Infarction / Q000209:etiology / Q000523:psychology / Q000628:therapy; D002548:Cerebral Revascularization / Q000379:methods*; D002560:Cerebrovascular Circulation; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D002532:Intracranial Aneurysm / Q000601:surgery*; D020767:Intracranial Thrombosis / Q000209:etiology / Q000628:therapy; D008297:Male; D008569:Memory Disorders / Q000209:etiology / Q000523:psychology; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods*; D011183:Postoperative Complications / Q000523:psychology; D012189:Retrospective Studies; D016896:Treatment Outcome
keywords: Anterior cerebral artery aneurysm; Bypass surgery; Modified Rankin Scale; Protective bypass; Surgical strategy