title: Evaluation of Onyx HD-500 embolic system in the treatment of 84 wide-neck intracranial aneurysms.
abstract: OBJECTIVE
  We report our results using Onyx HD-500 (Micro Therapeutics, Inc., Irvine, CA) in the endovascular treatment of wide-neck intracranial aneurysms, which have a high rate of incomplete occlusion and recanalization with platinum coils.
  
  
  METHODS
  Sixty-nine patients with 84 aneurysms were treated. Most of the aneurysms were located in the anterior circulation (80 of 84 aneurysms), were unruptured (74 of 84 aneurysms), and were incidental. Ten presented with subarachnoid hemorrhage, and 15 were symptomatic. All aneurysms had wide necks (neck >4 mm and/or dome-to-neck ratio <1.5). Fifty aneurysms were small (<12 mm), 30 were large (12 to <25 mm) and 4 were giant. Angiographic follow-up was available for 65 of the 84 aneurysms at 6 months, for 31 of the 84 aneurysms at 18 months, and for 5 of the 84 aneurysms at 36 months.
  
  
  RESULTS
  Complete aneurysm occlusion was seen in 65.5% of aneurysms on immediate control, in 84.6% at 6 months, and in 90.3% at 18 months. The rates of complete occlusion were 74%, 95.1%, and 95.2% for small aneurysms and 53.3%, 70%, and 80% for large aneurysms at the same follow-up periods. Progression from incomplete to complete occlusion was seen in 68.2% of all aneurysms, with a higher percentage in small aneurysms (90.9%). Aneurysm recanalization was observed in 3 patients (4.6%), with retreatment in 2 patients (3.3%). Procedural mortality was 2.9%. Overall morbidity was 7.2%.
  
  
  CONCLUSIONS
  Onyx embolization of intracranial wide-neck aneurysms is safe and effective. Morbidity and mortality rates are similar to those of other current endovascular techniques. Larger samples and longer follow-up periods are necessary.
authors.affiliation: Section of Interventional Neuroradiology, Med Imagem, Hospital Beneficencia Portuguesa, São Paulo, Brazil. roniepiske@uol.com.br
authors.forename: Ronie L
authors.initials: RL
authors.lastname: Piske
authors.forename: Luis H
authors.initials: LH
authors.lastname: Kanashiro
authors.forename: Eric
authors.initials: E
authors.lastname: Paschoal
authors.forename: Celso
authors.initials: C
authors.lastname: Agner
authors.forename: Sergio S
authors.initials: SS
authors.lastname: Lima
authors.forename: Paulo H
authors.initials: PH
authors.lastname: Aguiar
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D016001:Confidence Intervals; D004121:Dimethyl Sulfoxide / Q000737:chemistry / Q000627:therapeutic use*; D004621:Embolization, Therapeutic / Q000379:methods*; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods; D002532:Intracranial Aneurysm / Q000145:classification / Q000628:therapy*; D053208:Kaplan-Meier Estimate; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009333:Neck; D016017:Odds Ratio; D011145:Polyvinyls / Q000737:chemistry / Q000627:therapeutic use*; D012189:Retrospective Studies
chemical_list: C505752:Onyx HD 500; D011145:Polyvinyls; D004121:Dimethyl Sulfoxide