title: Sylvian fissure arteriovenous malformations: an application of the Sugita classification to 28 surgical patients.
abstract: OBJECTIVE
  The Sugita classification for sylvian fissure arteriovenous malformations (AVMs) categorizes them into four types based on nidus location in the fissure: pure, lateral, medial, and deep. This classification scheme is simple and appealing, but is rarely applied. We applied the Sugita classification to a consecutive, single-surgeon experience with 28 patients to better characterize the Sugita subtypes.
  
  
  METHODS
  Twenty-eight patients with sylvian fissure AVMs were identified from a series of 314 AVM patients treated microsurgically over a 9-year period. According to the Sugita classification, six (21%) AVMs were pure, four (14%) were lateral, nine (32%) were medial, and nine (32%) were deep. Fifteen (54%) patients presented with hemorrhage.
  
  
  RESULTS
  There was no surgical mortality in this experience. Four (14%) patients had transient deterioration and one (3.6%) patient with a pure sylvian AVM was permanently worse. At late follow-up (mean duration, 20 mo), good outcomes (Modified Rankin Scale scores 0-2) were observed in 25 (89%) patients.
  
  
  CONCLUSIONS
  The Sugita classification does not modify the surgical approach or predict patient outcomes with sylvian fissure AVMs, but it does clarify anatomic differences between subtypes. These AVMs are a diverse group, with each subtype having unique relationships between arteries, veins, nidus, and adjacent brain that influence microsurgical technique. Despite their eloquent location and technical challenges, results with microsurgical resection are excellent, making this the preferred treatment option for low-grade AVMs.
authors.affiliation: Department of Neurological Surgery, University of California, San Francisco, San Francisco, California 94143-0112, USA. lawtonm@neurosurg.ucsf.edu
authors.forename: Michael T
authors.initials: MT
authors.lastname: Lawton
authors.forename: Daniel C
authors.initials: DC
authors.lastname: Lu
authors.forename: William L
authors.initials: WL
authors.lastname: Young
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D002140:California / Q000453:epidemiology; D002535:Cerebral Aqueduct / Q000002:abnormalities* / Q000098:blood supply*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D002538:Intracranial Arteriovenous Malformations / Q000145:classification* / Q000175:diagnosis / Q000401:mortality / Q000601:surgery*; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D016019:Survival Analysis; D015996:Survival Rate; D016896:Treatment Outcome