title: Liquid 2-poly-hydroxyethyl-methacrylate embolization of experimental arteriovenous malformations: feasibility study.
abstract: OBJECTIVE
  We investigated the use of 2-poly-hydroxyethyl-methacrylate (2-P-HEMA) as an embolic agent in swine arteriovenous malformations (AVMs).
  
  
  METHODS
  In seven mini swine, experimental AVMs were created surgically. The aim of treatment was complete embolization of the nidus compartment filled by the feeding artery, without brain embolization. Six animals received pure liquid 2-P-HEMA, and one, 50% 2-P-HEMA. For radiopacity, liquid 2-P-HEMA was mixed with tungsten powder. Six animals underwent angiographic follow-up within 5-8 mo (mean, 6.5 mo). Evaluation criteria were controllability, procedural reproducibility, and duration of the nidus occlusion. To detect complications, brain MR imaging and CT were performed. Histopathologic studies were performed to prove occlusion and assess histopathologic responses.
  
  
  RESULTS
  2-P-HEMA was easily injected through microcatheters, with a reproducible technique. Because of the radiopacity of the mixture, deep nidus penetration was controlled with fluoroscopy and confirmed with CT and histopathologic examination. In five AVMs embolized with pure 2-P-HEMA, feeder obliteration was long term. One animal had vasospasm during embolization, and complete obliteration of the main feeder was maintained for 3 mo, but partial recanalization developed 2 mo later. One animal receiving pure 2-P-HEMA had an infarction. In the animal embolized with 50% 2-P-HEMA, angiography and CT revealed embolic material in the circle of Willis; the animal died after embolization. No marked inflammatory reaction in the vessel wall or perivascular tissue was observed in the embolized AVMs.
  
  
  CONCLUSIONS
  Experimental AVM embolization with pure 2-P-HEMA, made radiopaque with tungsten, is technically feasible in swine. Because of its properties, 2-P-HEMA has great potential as a therapeutic embolic agent.
authors.affiliation: Section of Neuroradiology, Department of Neurosurgery, University of Freiburg, Germany.
authors.forename: Joachim
authors.initials: J
authors.lastname: Klisch
authors.forename: Lin
authors.initials: L
authors.lastname: Yin
authors.forename: Flavio
authors.initials: F
authors.lastname: Requejo
authors.forename: Barbara
authors.initials: B
authors.lastname: Eissner
authors.forename: Kai M
authors.initials: KM
authors.lastname: Scheufler
authors.forename: Ralf
authors.initials: R
authors.lastname: Kubalek
authors.forename: Markus
authors.initials: M
authors.lastname: Buechner
authors.forename: Axel
authors.initials: A
authors.lastname: Pagenstecher
authors.forename: Heiner
authors.initials: H
authors.lastname: Nagursky
authors.forename: Martin
authors.initials: M
authors.lastname: Schumacher
mesh_terms: D015901:Angiography, Digital Subtraction; D000818:Animals; D002533:Cerebral Angiography; D004195:Disease Models, Animal; D004621:Embolization, Therapeutic / Q000379:methods*; D005240:Feasibility Studies; D002538:Intracranial Arteriovenous Malformations / Q000000981:diagnostic imaging / Q000473:pathology / Q000628:therapy*; D011102:Polyhydroxyethyl Methacrylate; D013552:Swine
chemical_list: D011102:Polyhydroxyethyl Methacrylate