title: Preoperative embolization of cerebral arteriovenous malformations with onyx.
abstract: OBJECTIVE
  Preoperative embolization facilitates the surgical management of complex cerebral arteriovenous malformations (cAVMs). This analysis aims to investigate the risks for preoperative cAVM embolization with Onyx.
  
  
  METHODS
  We retrospectively analyzed clinical data of all patients who underwent embolization with Onyx as a preoperative treatment of cAVMs at our institution since 2005 (US Food and Drug Administration [FDA] approval). Patients with arteriovenous fistulas were excluded. A total of 107 patients were treated for cAVMs during the study period. Of those patients, 41 underwent cAVM embolizations with Onyx in 82 procedures.
  
  
  RESULTS
  After the embolization, the cAVM diameter was reduced from 3.71 +/- 1.55 cm to 3.06 +/- 1.89 cm (P < .05). Median volume reduction was 75%. Complete occlusion with embolization alone was achieved in 4 (10%) cAVMs. The recurrence rate for completely occluded cAVMs was 50% (2 patients). A total of 71% of the 41 patients treated with Onyx underwent surgery, and 15% underwent radiosurgery. There were 9% who have not yet received definitive treatment of their residual cAVMs. A new permanent neurologic deficit occurred in 5 patients (6.1% per procedure or 12.2% per patient).
  
  
  CONCLUSIONS
  A considerable risk for a permanent neurologic deficit remains for cAVM embolization with Onyx. The risk has to be carefully weighted against the benefit of volume reduction in the treatment of cAVMs.
authors.affiliation: Department of Neurosurgery, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA. erik.hauck@utsouthwestern.edu
authors.forename: E F
authors.initials: EF
authors.lastname: Hauck
authors.forename: B G
authors.initials: BG
authors.lastname: Welch
authors.forename: J A
authors.initials: JA
authors.lastname: White
authors.forename: P D
authors.initials: PD
authors.lastname: Purdy
authors.forename: L G
authors.initials: LG
authors.lastname: Pride
authors.forename: D
authors.initials: D
authors.lastname: Samson
mesh_terms: D000293:Adolescent; D000328:Adult; D003131:Combined Modality Therapy; D004121:Dimethyl Sulfoxide; D004621:Embolization, Therapeutic / Q000009:adverse effects* / Q000379:methods / Q000401:mortality*; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000401:mortality / Q000601:surgery / Q000628:therapy; D008297:Male; D008875:Middle Aged; D009017:Morbidity; D011145:Polyvinyls; D011300:Preoperative Care; D012008:Recurrence; D012189:Retrospective Studies; D012307:Risk Factors; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: C450660:Onyx copolymer; D011145:Polyvinyls; D004121:Dimethyl Sulfoxide