title: National trends in spinal arteriovenous malformations.
abstract: OBJECTIVE
  Spinal arteriovenous malformations (AVMs) are rare and understudied vascular lesions that cause neurological insult by mass effect, venous obstruction, and vascular steal. These lesions are challenging entities to treat because of their complicated anatomy and physiology. Current management options include open microsurgery, endovascular embolization, and stereotactic radiosurgery.
  
  
  METHODS
  Our study used the National Inpatient Sample database to analyze outcome data for spinal AVMs treated nationwide over an 11-year period from 1995 through 2006. Trends in procedural management, hospital course, and epidemiology of spinal AVMs are investigated.
  
  
  RESULTS
  Annually, an average of 300 patients presented with spinal AVMs requiring hospital treatment. The average length of hospital stay for this treatment has declined from more than 9 days in 1995 to 6 days in 2006. However, the average cost of a hospital stay has increased from < $30,000 to nearly $70,000. Whereas one-half of spinal AVMs were treated operatively in 1995, one-third were managed operatively in 2006.
  
  
  CONCLUSIONS
  Spinal AVMs are being increasingly treated by endovascular, radiosurgical, or combined means. A discussion of modern strategies to treat these disorders is presented.
authors.affiliation: Department of Neurosurgery, Stanford University School of Medicine, Stanford, California, USA. nlad@stanford.edu
authors.forename: Shivanand P
authors.initials: SP
authors.lastname: Lad
authors.forename: Justin G
authors.initials: JG
authors.lastname: Santarelli
authors.forename: Chirag G
authors.initials: CG
authors.lastname: Patil
authors.forename: Gary K
authors.initials: GK
authors.lastname: Steinberg
authors.forename: Maxwell
authors.initials: M
authors.lastname: Boakye
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000369:Aged, 80 and over; D020785:Central Nervous System Vascular Malformations / Q000191:economics / Q000453:epidemiology* / Q000628:therapy*; D002648:Child; D002675:Child, Preschool; D016208:Databases, Factual / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D007223:Infant; D007297:Inpatients / Q000706:statistics & numerical data; D007902:Length of Stay / Q000706:statistics & numerical data / Q000639:trends; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D012737:Sex Factors; D020758:Spinal Cord Vascular Diseases / Q000191:economics / Q000453:epidemiology* / Q000628:therapy*; D014481:United States; D014483:United States Dept. of Health and Human Services / Q000706:statistics & numerical data; D014656:Vascular Surgical Procedures / Q000379:methods / Q000706:statistics & numerical data; D055815:Young Adult