title: Combined therapy of cerebral arteriovenous malformations: histological differences between a non-adhesive liquid embolic agent and n-butyl 2-cyanoacrylate (NBCA).
abstract: OBJECTIVE
  Based on 2 casuistics, the intraoperative qualities of a new, non-adhesive liquid embolic agent (Onyx, Micro Therapeutics. Inc., Irvine, CA, USA) are to be compared to those of n-butyl 2-cyanoacrylate (NBCA) with regard to the histopathological results after preoperative embolization of a cerebral arteriovenous malformation (AVM).
  
  
  METHODS
  In a case example, the intraoperative quality of the nidus after embolization of a parieto-occipital AVM with Onyx--a new, non-adhesive liquid embolic agent--consisting of ethylene-vinyl alcohol copolymer (EVOH), dimethyl sulfoxide (DMSO) and tantalum, is described. In the second patient, embolization of a frontal high-flow AVM was performed with NBCA. Both patients underwent surgery with complete resection ofthe AVM.
  
  
  RESULTS
  From a neurosurgical point of view, Onyx is suitable for preoperative embolization of AVMs, because the nidus intraoperatively remains elastic and formable and can be dissected from the surrounding brain tissue quite well by microsurgical technique. Inflammatory reactions can be found mainly in the lumina of the vessels.
  
  
  CONCLUSIONS
  Onyx promises to be an embolic agent well suitable for subsequent neurosurgical resection. Further studies considering various intervals of time between embolization and resection as well as histopathological and electron microscopical examinations are necessary for evaluation of our first experience with this new embolization agent.
authors.affiliation: Department of Neurosurgery, University Hospital, Eberhard-Karls University, Tübingen, Germany. frank.duffner@med.uni-tuebingen.de
authors.forename: F
authors.initials: F
authors.lastname: Duffner
authors.forename: R
authors.initials: R
authors.lastname: Ritz
authors.forename: A
authors.initials: A
authors.lastname: Bornemann
authors.forename: D
authors.initials: D
authors.lastname: Freudenstein
authors.forename: H
authors.initials: H
authors.lastname: Wiendl
authors.forename: R
authors.initials: R
authors.lastname: Siekmann
mesh_terms: D000328:Adult; D002533:Cerebral Angiography; D004121:Dimethyl Sulfoxide; D004621:Embolization, Therapeutic / Q000379:methods*; D004659:Enbucrilate / Q000031:analogs & derivatives*; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery / Q000628:therapy*; D008297:Male; D019635:Neurosurgical Procedures; D011145:Polyvinyls; D011300:Preoperative Care; D013635:Tantalum; D014014:Tissue Adhesives / Q000627:therapeutic use*
chemical_list: D011145:Polyvinyls; D014014:Tissue Adhesives; C020320:ethylene-vinyl alcohol copolymer; D013635:Tantalum; D004659:Enbucrilate; D004121:Dimethyl Sulfoxide