title: Clinical presentation and treatment of distal posterior inferior cerebellar artery aneurysms.
abstract: Aneurysms located at the distal portion of the posterior inferior cerebellar artery (PICA) are rare, and their clinical features are not fully understood. We report the clinical features and management of 30 distal PICA aneurysms in 28 patients treated during the past decade at Kagoshima University Hospital and affiliated hospitals. Our series includes 20 women and eight men. Of their 30 aneurysms, 24 were ruptured, and six were unruptured; there were 27 saccular and two fusiform aneurysms; one was dissecting. Their location was at the anterior-medullary (n = 4), lateral-medullary (n = 9), tonsillomedullary (n = 7), telovelotonsillar (n = 6), and cortical (n = 4) segment of the PICA. In 18 patients, angiographic features suggested hemodynamic stress including an absent contralateral PICA or ipsilateral anterior inferior cerebellar artery, termination of the vertebral artery (VA) at the PICA, and hyperplasia or occlusion of the contralateral VA. As three patients died before surgery, 27 aneurysms in 25 patients were surgically treated. Of these, 6 were unruptured aneurysms; 20 were clipped via midline or lateral suboccipital craniotomy, and 5 were embolized with Guglielmi coils; in one, the PICA flow was reconstructed by OA-PICA anastomosis, and in the other one, the PICA was resected. Of the 25 surgically treated patients, 22 (88%) had good outcomes. The predominant contributor to the development of distal PICA aneurysms is thought to be increased hemodynamic stress attributable to anomalies in the PICA and related posterior circulation. Both direct clipping and coil embolization yielded favorable outcomes in our series. However, considering the difficulties that may be encountered at direct clipping in the acute stage and the availability of advanced techniques and instrumentation, aneurysmal coiling is now the first option to address these aneurysms.
authors.affiliation: Department of Neurosurgery, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima 890-8520, Japan. hiroshitok@nag.bbiq.jp
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Tokimura
authors.forename: Hitoshi
authors.initials: H
authors.lastname: Yamahata
authors.forename: Takashi
authors.initials: T
authors.lastname: Kamezawa
authors.forename: Kenichiro
authors.initials: K
authors.lastname: Tajitsu
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Nagayama
authors.forename: Sei
authors.initials: S
authors.lastname: Sugata
authors.forename: Kosuke
authors.initials: K
authors.lastname: Takiguchi
authors.forename: Ayumi
authors.initials: A
authors.lastname: Taniguchi
authors.forename: Masaki
authors.initials: M
authors.lastname: Niiro
authors.forename: Kazuho
authors.initials: K
authors.lastname: Hirahara
authors.forename: Koji
authors.initials: K
authors.lastname: Takasaki
authors.forename: Tatsuki
authors.initials: T
authors.lastname: Oyoshi
authors.forename: Kazunori
authors.initials: K
authors.lastname: Arita
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002526:Cerebellar Diseases / Q000175:diagnosis* / Q000628:therapy*; D002533:Cerebral Angiography; D002536:Cerebral Arteries / Q000473:pathology*; D002560:Cerebrovascular Circulation; D005260:Female; D006261:Headache / Q000209:etiology; D006801:Humans; D002532:Intracranial Aneurysm / Q000175:diagnosis* / Q000628:therapy*; D018810:Magnetic Resonance Angiography; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009325:Nausea / Q000209:etiology; D014057:Tomography, X-Ray Computed; D016896:Treatment Outcome; D014786:Vision Disorders / Q000209:etiology