title: Posterior fossa brain arteriovenous malformations : Clinical features and outcomes of endovascular embolization, adjuvant microsurgery and radiosurgery.
abstract: BACKGROUND
  Posterior fossa brain arteriovenous malformations (PFbAVM) are relatively rare brain disorders but have a high risk of hemorrhage. Endovascular embolization to reduce the lesion size before treatment may improve the outcome of PFbAVM. The purposes of this study were to identify risk factors associated with hemorrhage in PFbAVM and to assess clinical outcomes in patients receiving initial endovascular embolization.
  
  
  METHODS
  From 1999 to 2013 a total of 63 patients with PFbAVMs were treated (31 males and 32 females, 14.1 % of all AVM cases). A retrospective examination of patient demographics, clinical presentation, angiographic features, treatment modalities, complications and outcomes was carried out. The re-hemorrhage rate, obliteration rate and modified Rankin scale (MRS) were used as measures of outcome.
  
  
  RESULTS
  Of the 63 PFbAVM patients 54 (85.7 %) exhibited hemorrhage and 15 had confirmed aneurysms. The cerebellar location (P = 0.007) and deep venous drainage (P = 0.012) were independent predictors of hemorrhage in multivariate analyses. The mean estimated devascularization was 46.9 % (range 10-100 %) in the 20 patients (31.7 %) treated by endovascular embolization. The 16 patients with residual niduses were further treated by radiosurgery, microsurgery or embolization. Complete obliteration was attained in 12 patients (67 %) while 2 (5.7 %) were left with persisting neurological deficits and 1 had a re-hemorrhage 3 years later (annual rate of 4.6 %). Favorable outcome (MRS ≤ 2) was obtained in the 20 patients receiving initial endovascular embolization (P = 0.039 versus preoperative MRS).
  
  
  CONCLUSIONS
  Cerebellar location and deep venous drainage are predictors of hemorrhage in PFbAVM. Adjuvant endovascular embolization is useful and safe for PFbAVM prior to microsurgery or radiosurgery.
authors.affiliation: The National Key Clinical Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, 510282, Guangzhou, China.
authors.forename: Ling-Feng
authors.initials: LF
authors.lastname: Lai
authors.affiliation: The National Key Clinical Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, 510282, Guangzhou, China.
authors.forename: Jia-Xiang
authors.initials: JX
authors.lastname: Chen
authors.affiliation: The National Key Clinical Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, 510282, Guangzhou, China.
authors.forename: Kuang
authors.initials: K
authors.lastname: Zheng
authors.affiliation: The National Key Clinical Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, 510282, Guangzhou, China.
authors.forename: Xu-Ying
authors.initials: XY
authors.lastname: He
authors.affiliation: The National Key Clinical Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, 510282, Guangzhou, China.
authors.forename: Xi-Feng
authors.initials: XF
authors.lastname: Li
authors.affiliation: The National Key Clinical Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, 510282, Guangzhou, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Zhang
authors.affiliation: The National Key Clinical Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, 510282, Guangzhou, China.
authors.forename: Qiu-Jing
authors.initials: QJ
authors.lastname: Wang
authors.affiliation: The National Key Clinical Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, 510282, Guangzhou, China. duanchuanz@163.com.
authors.forename: Chuan-Zhi
authors.initials: CZ
authors.lastname: Duan
authors.affiliation: The National Key Clinical Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, 510282, Guangzhou, China.
authors.forename: Min
authors.initials: M
authors.lastname: Chen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D004621:Embolization, Therapeutic; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000628:therapy*; D008297:Male; D008866:Microsurgery; D008875:Middle Aged; D016634:Radiosurgery; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult
keywords: Cerebral hemorrhage; Endovascular embolization; Intracranial aneurysm; Outcome; Retrospective study