title: Induced-Wedge Technique to Improve Liquid Embolic Agent Penetration into Spinal Dural Arteriovenous Fistula.
abstract: OBJECTIVE
  To promote embolization of spinal dural arteriovenous fistula (SDAVF) with a small long tortuous feeder that may impede successful application of an embolic agent.
  
  
  METHODS
  An induced-wedge technique was developed in which blood flow was blocked by coiling at the proximal part of the microcatheter for secure injection of N-butyl cyanoacrylate. We used this technique in 11 patients with SDAVF (male/female ratio, 8:3): 7 thoracic, 2 lumbar, 1 sacral, and 1 cervical. Clinical outcome was evaluated by the Aminoff-Logue Disability Scale.
  
  
  RESULTS
  Penetration of embolic agent through the fistula into the vein was complete (n = 5), nearly complete (no penetration of embolic agent into the vein but no residual fistula on 3 adjacent selective angiograms; n = 4), or partial (embolization with a small residual filling of the draining vein; n = 2). All patients improved neurologically during follow-up (median, 18 months; range, 7-37 months) and achieved complete recovery. Of the 2 patients who obtained partial obliteration, one showed disappearance of the residual lesion on angiography 21 months later and the other achieved complete results after repeat embolization.
  
  
  CONCLUSIONS
  The induced-wedge technique can improve SDAVF embolization by providing better penetration of the liquid embolic agent to the fistula and vein.
authors.affiliation: Department of Radiology, University of Ulsan, College of Medicine, Asan Medical Center, Songpa-gu, Seoul, Korea. Electronic address: dcsuh@amc.seoul.kr.
authors.forename: Dae Chul
authors.initials: DC
authors.lastname: Suh
authors.affiliation: Department of Radiology, University of Ulsan, College of Medicine, Asan Medical Center, Songpa-gu, Seoul, Korea.
authors.forename: Su Hee
authors.initials: SH
authors.lastname: Cho
authors.affiliation: Department of Radiology, University of Ulsan, College of Medicine, Asan Medical Center, Songpa-gu, Seoul, Korea.
authors.forename: Ji Eun
authors.initials: JE
authors.lastname: Park
authors.affiliation: Department of Radiology, University of Ulsan, College of Medicine, Asan Medical Center, Songpa-gu, Seoul, Korea; Department of Interventional Radiology, Taizhou People's Hospital, Taizhou, Jiangsu Province, China.
authors.forename: Hairi
authors.initials: H
authors.lastname: Liu
authors.affiliation: Department of Radiology, University of Ulsan, College of Medicine, Asan Medical Center, Songpa-gu, Seoul, Korea.
authors.forename: Sung Chul
authors.initials: SC
authors.lastname: Jung
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D015901:Angiography, Digital Subtraction; D020785:Central Nervous System Vascular Malformations / Q000000981:diagnostic imaging / Q000601:surgery*; D004121:Dimethyl Sulfoxide / Q000627:therapeutic use*; D004621:Embolization, Therapeutic / Q000379:methods*; D004659:Enbucrilate / Q000627:therapeutic use*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D011145:Polyvinyls / Q000627:therapeutic use*; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: C450660:Onyx copolymer; D011145:Polyvinyls; D004659:Enbucrilate; D004121:Dimethyl Sulfoxide
keywords: Embolization technique; Glue embolization; Spinal dural arteriovenous fistula