title: Validation of an 'endovascular-first' approach to spinal dural arteriovenous fistulas: an intention-to-treat analysis.
abstract: OBJECTIVE
  Spinal dural arteriovenous fistulas (SDAVFs) require pretreatment angiography; embolization can be performed in the same session. To validate this approach, obliteration and morbidity rates of 'endovascular-first' (embolization and microsurgery in the case of embolization failures) must be compared with rates for 'microsurgery-first' (microsurgical ligation without attempted embolization) approaches.
  
  
  METHODS
  We reviewed our institutional database (January 1998-October 2015) for SDAVFs, performing an intention-to-treat analysis comparing endovascular-first and microsurgery-first approaches.
  
  
  RESULTS
  A total of 71 patients underwent surgical and/or endovascular treatment for SDAVFs. All SDAVFs were ultimately occluded. Of 35 patients under consideration for an endovascular-first approach, radicular artery anatomy or anterior spinal artery embolization risk precluded attempting embolization in seven cases (20%). Among 28 patients undergoing embolization, angiographic non-opacification of the fistula was noted in 18 (64%). Fourteen patients had obliteration with excellent casting of the draining vein (50%) and did not undergo surgery. There were no significant differences in total complications (9% vs 11%; p=1.0) or permanent complications (3% vs 4%; p=1.0) after attempted endovascular and surgical treatment. Based on an intention-to-treat analysis, there were no significant differences in total complications (11% vs 14%; p=1.0), permanent complications (6% vs 3%; p=0.61), or the symptomatic resolution/improvement rate (80% vs 78%; p=1.0) between endovascular-first and microsurgery-first groups.
  
  
  CONCLUSIONS
  Our results support attempted embolization of SDAVFs prior to consideration of microsurgery, allowing for a less invasive treatment option in the same session as diagnostic angiography.
authors.affiliation: Department of Neurosurgery, Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, Arizona, USA.
authors.forename: Bradley A
authors.initials: BA
authors.lastname: Gross
authors.affiliation: Department of Neurosurgery, Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, Arizona, USA.
authors.forename: Felipe C
authors.initials: FC
authors.lastname: Albuquerque
authors.affiliation: Department of Neurosurgery, Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, Arizona, USA.
authors.forename: Karam
authors.initials: K
authors.lastname: Moon
authors.affiliation: Department of Neurosurgery, Barrow Neurological Institute, St Joseph's Hospital and Medical Center, Phoenix, Arizona, USA.
authors.forename: Cameron G
authors.initials: CG
authors.lastname: McDougall
mesh_terms: D000328:Adult; D000368:Aged; D000792:Angiography; D001164:Arteriovenous Fistula / Q000000981:diagnostic imaging / Q000601:surgery; D020785:Central Nervous System Vascular Malformations / Q000000981:diagnostic imaging* / Q000601:surgery*; D004621:Embolization, Therapeutic / Q000379:methods; D057510:Endovascular Procedures / Q000379:methods*; D005260:Female; D006801:Humans; D057194:Intention to Treat Analysis / Q000379:methods*; D008297:Male; D008866:Microsurgery / Q000379:methods; D008875:Middle Aged; D012189:Retrospective Studies; D013116:Spinal Cord / Q000098:blood supply / Q000000981:diagnostic imaging / Q000601:surgery; D016896:Treatment Outcome; D014711:Vertebral Artery / Q000000981:diagnostic imaging / Q000601:surgery
keywords: Fistula; Liquid Embolic Material; Spine; Vascular Malformation