title: The limitations and risks of transarterial Onyx injections in the treatment of grade I and II DAVFs.
abstract: OBJECTIVE
  Embolization of grade III-V intracranial DAVFs using Onyx is feasible with promising results, indicating stability at the time of mid-term follow-up. This article is to evaluate the role of transarterial Onyx embolization in the treatment of grade I and II intracranial dural arteriovenous fistulas (DAVFs), including its limitations and risks.
  
  
  METHODS
  We retrospectively studied consecutive 26 patients (8 women and 18 men) treated for an grade I and II intracranial DAVF since 2006 in whom a transarterial approach was attempted with Onyx-18 embolization. There were 18 transverse-sigmoid sinus, 4 cavernous sinus, 2 superior sagittal sinus, 1 inferior petrosal sinus and 1 intradiploic fistulas. Five fistulas were Type I, 8 were Type IIa, and 13 were Type IIa+b, according to the Cognard classification. The mean clinical follow-up period was 15.6 months.
  
  
  RESULTS
  Anatomic cure was proven in 13 patients (50%) and clinical cure was obtained in 17 cases (65.4%). These 13 cures were achieved after a single procedure. All these 13 patients underwent a follow-up angiography, which has confirmed the complete cure. Partial occlusion was obtained in 13 patients. Complications were as follows: 2 cardiac Onyx migration, 2 reflexive bradyarrythmia, 1 transient visual hallucination, 2 transient fifth nerve palsies and 1 permanent seventh nerve palsy in inferior petrosal sinus DAVF.
  
  
  CONCLUSIONS
  Based on this experience, grade I and II intracranial DAVFs may be treated with transarterial Onyx embolization to reduce the shunted blood flow and to facilitate subsequent transvenous embolization or surgery.
authors.affiliation: Beijing Neurosurgical Institute and Beijing Tiantan Hospital, Capital Medical University, No. 6, Tiantan Xili, Chongwen, Beijing 100050, China. lvxianli000@163.com
authors.forename: Xianli
authors.initials: X
authors.lastname: Lv
authors.forename: Chuhan
authors.initials: C
authors.lastname: Jiang
authors.forename: Youxiang
authors.initials: Y
authors.lastname: Li
authors.forename: Lian
authors.initials: L
authors.lastname: Liu
authors.forename: Jie
authors.initials: J
authors.lastname: Liu
authors.forename: Zhongxue
authors.initials: Z
authors.lastname: Wu
mesh_terms: D000293:Adolescent; D000328:Adult; D020785:Central Nervous System Vascular Malformations / Q000000981:diagnostic imaging / Q000628:therapy*; D002561:Cerebrovascular Disorders / Q000000981:diagnostic imaging / Q000628:therapy*; D004121:Dimethyl Sulfoxide / Q000008:administration & dosage* / Q000009:adverse effects; D004621:Embolization, Therapeutic / Q000009:adverse effects / Q000379:methods*; D005260:Female; D006490:Hemostatics / Q000008:administration & dosage; D006801:Humans; D007269:Injections, Intra-Arterial; D008297:Male; D008875:Middle Aged; D011145:Polyvinyls / Q000008:administration & dosage* / Q000009:adverse effects; D011859:Radiography; D012307:Risk Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D006490:Hemostatics; C450660:Onyx copolymer; D011145:Polyvinyls; D004121:Dimethyl Sulfoxide