Induced-Wedge Technique to Improve Liquid Embolic Agent Penetration into Spinal Dural Arteriovenous Fistula

World Neurosurg. 2016 Dec;96:309-315. doi: 10.1016/j.wneu.2016.09.002. Epub 2016 Sep 13.


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.

Keywords: Embolization technique; Glue embolization; Spinal dural arteriovenous fistula.

MeSH terms

  • Aged
  • Aged, 80 and over
  • Angiography, Digital Subtraction
  • Central Nervous System Vascular Malformations / diagnostic imaging
  • Central Nervous System Vascular Malformations / surgery*
  • Dimethyl Sulfoxide / therapeutic use*
  • Embolization, Therapeutic / methods*
  • Enbucrilate / therapeutic use*
  • Female
  • Humans
  • Magnetic Resonance Imaging
  • Male
  • Middle Aged
  • Polyvinyls / therapeutic use*
  • Retrospective Studies
  • Treatment Outcome


  • Onyx copolymer
  • Polyvinyls
  • Enbucrilate
  • Dimethyl Sulfoxide