title: Microvascular pathological features of immediate perinidal parenchyma in cerebral arteriovenous malformations: giant bed capillaries.
abstract: OBJECTIVE
  The behavior of brain tissue in cases of arteriovenous malformations (AVMs) is a matter of debate. The authors believe that the local microvascular environment in the AVM bed shares the hemodynamic changes influencing that behavior in one way or another. The purpose of this study was to investigate the microvascular pathological features in the immediate perinidal brain tissue.
  
  
  METHODS
  This retrospective study was conducted using excised AVM specimens obtained in 35 patients, from which the authors selected 20 specimens that fulfilled the criteria for sufficient brain tissue around the excised nidus. Specimens were stained with hematoxylin and eosin, and the immediate perinidal microvascular environment was examined using light microscopy.
  
  
  CONCLUSIONS
  Eighty-five percent of the AVMs studied showed the presence of huge, dilated capillaries, and 65% showed severe congestion of these capillaries. The authors have named these capillaries "giant bed capillaries." In this study capillary bleeding was shown in AVMs, and a pericapillary space was seen around some vessels. The brain parenchyma containing AVMs with these findings proved to be significantly ischemic.
authors.affiliation: Department of Neurosurgery, Shinshu University School of Medicine, Matsumoto, Nagano, Japan.
authors.forename: Walid
authors.initials: W
authors.lastname: Attia
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Tada
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Hongo
authors.forename: Hisashi
authors.initials: H
authors.lastname: Nagashima
authors.forename: Toshiki
authors.initials: T
authors.lastname: Takemae
authors.forename: Yuichiro
authors.initials: Y
authors.lastname: Tanaka
authors.forename: Shigeaki
authors.initials: S
authors.lastname: Kobayashi
mesh_terms: D000293:Adolescent; D001921:Brain / Q000098:blood supply / Q000473:pathology; D002545:Brain Ischemia / Q000209:etiology / Q000473:pathology; D002196:Capillaries / Q000473:pathology; D002675:Child, Preschool; D046508:Culture Techniques; D005260:Female; D006439:Hemodynamics / Q000502:physiology; D006801:Humans; D007223:Infant; D002538:Intracranial Arteriovenous Malformations / Q000150:complications / Q000473:pathology* / Q000601:surgery; D008297:Male; D019635:Neurosurgical Procedures; D012189:Retrospective Studies; D012720:Severity of Illness Index