title: Risk Factors for Subsequent Hemorrhage in Patients with Cerebellar Arteriovenous Malformations.
abstract: OBJECTIVE
  The aim of this study was to identify the risk factors for subsequent hemorrhage in patients with untreated cerebellar arteriovenous malformations (AVMs).
  
  
  METHODS
  We searched our AVM database at Beijing Tiantan Hospital and identified 149 patients with cerebellar AVMs who were at least 1 month treatment free after initial diagnosis between 2000 and 2015. The patients were followed up from initial diagnosis until subsequent hemorrhage, initiation of treatment, or the end of 2015. The natural history of cerebellar AVMs was analyzed.
  
  
  RESULTS
  The overall annual rupture rate was 8.6%, with a mean follow-up period of 4.2 years (range, 1 month to 15 years). The annual rupture rate for previously ruptured AVMs was 10.8% during the whole follow-up period, 12.4% in the first 5 years (18.8% in the first year and 9.0% in the subsequent 4 years) and 6.7% in more than 5 years after initial diagnosis. The overall annual rupture rate for previously unruptured AVMs was 4.0%. Childhood at diagnosis, AVM size ≥3 cm and exclusively deep venous drainage were independent risk factors for subsequent hemorrhage. Previous AVM rupture significantly increased the hemorrhagic risk during the first 5 years but did not significantly affect subsequent hemorrhage thereafter.
  
  
  CONCLUSIONS
  Childhood at diagnosis, large AVM size, and AVMs with exclusively deep venous drainage are independent risk factors for subsequent hemorrhage in patients with cerebellar AVMs. Previous rupture may increase the hemorrhagic risk during the first 5 years after diagnosis but may not significantly increase the risk in the following years.
authors.affiliation: Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, People's Republic of China; China National Clinical Research Center for Neurological Diseases, Beijing, People's Republic of China; Center of Stroke, Beijing Institute for Brain Disorders, Beijing, People's Republic of China; Beijing Key Laboratory of Translational Medicine for Cerebrovascular Diseases, Beijing, People's Republic of China.
authors.forename: Xianzeng
authors.initials: X
authors.lastname: Tong
authors.affiliation: Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, People's Republic of China; China National Clinical Research Center for Neurological Diseases, Beijing, People's Republic of China; Center of Stroke, Beijing Institute for Brain Disorders, Beijing, People's Republic of China; Beijing Key Laboratory of Translational Medicine for Cerebrovascular Diseases, Beijing, People's Republic of China.
authors.forename: Jun
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, People's Republic of China; China National Clinical Research Center for Neurological Diseases, Beijing, People's Republic of China; Center of Stroke, Beijing Institute for Brain Disorders, Beijing, People's Republic of China; Beijing Key Laboratory of Translational Medicine for Cerebrovascular Diseases, Beijing, People's Republic of China.
authors.forename: Fuxin
authors.initials: F
authors.lastname: Lin
authors.affiliation: Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, People's Republic of China; China National Clinical Research Center for Neurological Diseases, Beijing, People's Republic of China; Center of Stroke, Beijing Institute for Brain Disorders, Beijing, People's Republic of China; Beijing Key Laboratory of Translational Medicine for Cerebrovascular Diseases, Beijing, People's Republic of China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Cao
authors.affiliation: Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, People's Republic of China; China National Clinical Research Center for Neurological Diseases, Beijing, People's Republic of China; Center of Stroke, Beijing Institute for Brain Disorders, Beijing, People's Republic of China; Beijing Key Laboratory of Translational Medicine for Cerebrovascular Diseases, Beijing, People's Republic of China.
authors.forename: Yuanli
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, People's Republic of China; China National Clinical Research Center for Neurological Diseases, Beijing, People's Republic of China; Center of Stroke, Beijing Institute for Brain Disorders, Beijing, People's Republic of China; Beijing Key Laboratory of Translational Medicine for Cerebrovascular Diseases, Beijing, People's Republic of China. Electronic address: captain9858@vip.sina.com.
authors.forename: Shuo
authors.initials: S
authors.lastname: Wang
authors.affiliation: Department of Neurosurgery, Beijing Tiantan Hospital, Capital Medical University, Beijing, People's Republic of China; China National Clinical Research Center for Neurological Diseases, Beijing, People's Republic of China; Center of Stroke, Beijing Institute for Brain Disorders, Beijing, People's Republic of China; Beijing Key Laboratory of Translational Medicine for Cerebrovascular Diseases, Beijing, People's Republic of China.
authors.forename: Jizong
authors.initials: J
authors.lastname: Zhao
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D002526:Cerebellar Diseases / Q000150:complications*; D002543:Cerebral Hemorrhage / Q000453:epidemiology* / Q000209:etiology*; D002648:Child; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000150:complications*; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D015233:Models, Statistical; D012189:Retrospective Studies; D012307:Risk Factors; D012737:Sex Factors; D055815:Young Adult
keywords: Cerebellar arteriovenous malformations (AVMs); Hemorrhagic risk; Natural history