title: Ideal clipping methods for unruptured middle cerebral artery bifurcation aneurysms based on aneurysmal neck classification.
abstract: Endovascular coiling is widely used for many cerebral aneurysms; however, in cases of middle cerebral artery bifurcation (MCBIF) aneurysms, it is associated with a higher incidence of unfavorable outcomes compared to microsurgical clippings. In this retrospective study, we aimed to investigate the outcomes of microsurgical clipping for unruptured MCBIF aneurysms and determine the ideal clipping methods for different aneurysm subtypes. From January 2011 to December 2013, 203 aneurysms with saccular shape (<25 mm) were treated by an experienced neurosurgeon. Depending on the involvement of the aneurysmal thin wall, the aneurysm neck was classified as follows: subtype I, limited bifurcation; subtype II, progressed to M1 trunk; subtype III, progressed to M2 trunk; subtype IV, progressed to M1 and one M2 trunk; and subtype V, progressed to M1 and two M2 trunks. The clipping methods included simple, sliding, interlocking, or mixed approaches. Aneurysm clippings were accomplished without any morbidity in all cases, and seven cases had a minimal neck remnant. The following clipping methods were predominantly used: subtype I, simple (90.2%) and sliding (8.8%) (mean = 1.2 clips); subtype II, interlocking (51.4%), sliding (30.0%), mixed (15.7%), and simple (2.9%) (2.4 clips); subtype III, simple (57.5%) and sliding (42.5%) (1.5 clips); subtype IV, interlocking (64.3%) (2.1 clips), simple (10.7%), sliding (14.3%), and mixed (10.7%); and subtype V, interlocking (50.0%), sliding (35.7%), and mixed (14.3%) methods with multiple clips (2.8 clips). If an appropriate clipping method is selected according to the neck classification, satisfactory surgical obliteration can be achieved for unruptured MCBIF aneurysms without morbidity.
authors.affiliation: Department of Neurosurgery, Kangdong Sacred Heart Hospital, Hallym University College of Medicine, 150, Seongan-ro, Gangdong-gu, Seoul, 134-701, Republic of Korea.
authors.forename: Hong Jun
authors.initials: HJ
authors.lastname: Jeon
authors.affiliation: Department of Neurosurgery, Severance Hospital, Stroke Center, Yonsei University College of Medicine, 50-1, Yonsei-ro, Seodaemon-gu, Seoul, 120-752, Republic of Korea.
authors.forename: So Yeon
authors.initials: SY
authors.lastname: Kim
authors.affiliation: Department of Neurosurgery, Severance Hospital, Stroke Center, Yonsei University College of Medicine, 50-1, Yonsei-ro, Seodaemon-gu, Seoul, 120-752, Republic of Korea.
authors.forename: Keun Young
authors.initials: KY
authors.lastname: Park
authors.affiliation: Department of Neurosurgery, Severance Hospital, Stroke Center, Yonsei University College of Medicine, 50-1, Yonsei-ro, Seodaemon-gu, Seoul, 120-752, Republic of Korea. leejw@yuhs.ac.
authors.forename: Jae Whan
authors.identifier: http://orcid.org/0000-0002-3968-998X
authors.initials: JW
authors.lastname: Lee
authors.affiliation: Department of Neurosurgery, Severance Hospital, Stroke Center, Yonsei University College of Medicine, 50-1, Yonsei-ro, Seodaemon-gu, Seoul, 120-752, Republic of Korea.
authors.forename: Seung Kon
authors.initials: SK
authors.lastname: Huh
mesh_terms: D000328:Adult; D000368:Aged; D002539:Cerebral Arterial Diseases / Q000601:surgery*; D004621:Embolization, Therapeutic / Q000379:methods; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000601:surgery*; D008297:Male; D008866:Microsurgery / Q000379:methods; D008875:Middle Aged; D020768:Middle Cerebral Artery / Q000601:surgery*; D019635:Neurosurgical Procedures; D012189:Retrospective Studies; D013525:Surgical Instruments
keywords: Intracranial aneurysm; Microsurgery; Middle cerebral artery; Neck classification