title: Clinical presentation and treatment of distal anterior inferior cerebellar artery aneurysms.
abstract: Aneurysms located at the distal portion of the anterior inferior cerebellar artery (AICA) are rare, and their clinical features are not fully understood. We report the clinical features and management of nine distal AICA aneurysms in nine patients treated during the past decade at Kagoshima University Hospital and affiliated hospitals. Our series includes seven women and two men. Of their nine aneurysms, eight were ruptured and one was unruptured; six were saccular and three were dissecting aneurysms. The most prevalent location was the meatal loop (n = 5) followed by the postmeatal (n = 3) and premeatal segment (n = 1) of the AICA, suggesting hemodynamic stress as an etiology of these distal AICA aneurysms. Of the nine patients, five presented with angiographic features suggestive of increased hemodynamic stress to the AICA and the common trunk of the posterior inferior cerebellar artery, with vertebral artery stenosis, marked laterality, and a primitive hypoglossal artery. We addressed eight aneurysms (eight patients) surgically; one aneurysm in one patient disappeared in the course of 3 months without surgical treatment. Of the eight surgically treated aneurysms, seven were ruptured and one was unruptured, five were clipped via lateral suboccipital craniotomy, two were trapped via lateral suboccipital craniotomy, and one was embolized. Good outcomes were obtained in six of the eight patients who underwent operation (75 %). We consider increased hemodynamic stress attributable to anatomic variations in the AICA and related posterior circulation to be the predominant contributor to the development of distal AICA aneurysms. Direct clipping and trapping yielded favorable outcomes in our series.
authors.affiliation: Department of Neurosurgery, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, Kagoshima, 890-8544, Japan. hiroshitok@nag.bbiq.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tokimura
authors.forename: Takashi
authors.initials: T
authors.lastname: Ishigami
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Yamahata
authors.forename: Hajime
authors.initials: H
authors.lastname: Yonezawa
authors.forename: Shunichi
authors.initials: S
authors.lastname: Yokoyama
authors.forename: Akihiro
authors.initials: A
authors.lastname: Haruzono
authors.forename: Soichi
authors.initials: S
authors.lastname: Obara
authors.forename: Yosuke
authors.initials: Y
authors.lastname: Nishimuta
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Nagayama
authors.forename: Kazuho
authors.initials: K
authors.lastname: Hirahara
authors.forename: Takashi
authors.initials: T
authors.lastname: Kamezawa
authors.forename: Sei
authors.initials: S
authors.lastname: Sugata
authors.forename: Kazunori
authors.initials: K
authors.lastname: Arita
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D017542:Aneurysm, Ruptured / Q000601:surgery; D002526:Cerebellar Diseases / Q000473:pathology / Q000601:surgery*; D002533:Cerebral Angiography; D002560:Cerebrovascular Circulation / Q000502:physiology; D015897:Comorbidity; D004621:Embolization, Therapeutic; D005260:Female; D023261:Glasgow Outcome Scale; D006801:Humans; D002532:Intracranial Aneurysm / Q000473:pathology / Q000601:surgery*; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019635:Neurosurgical Procedures / Q000379:methods*; D012189:Retrospective Studies; D013345:Subarachnoid Hemorrhage / Q000209:etiology / Q000601:surgery; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D055815:Young Adult