title: Perioperative microdialysis in meningioma surgery: correlation of cerebral metabolites with clinical outcome.
abstract: BACKGROUND
  Brain tumour resection requires surgical manoeuvres that may cause an ischaemic injury to peritumoral tissue. The aim of the present study was to examine whether putative alterations in peritumoral tissue biochemistry, monitored by microdialysis, correlate with clinical outcome in patients undergoing craniotomy for meningioma resection.
  
  
  METHODS
  In 34 patients undergoing meningioma resection (35 % male; mean age ± SD: 54.3 ± 12.1 years), microdialysis measurements were taken perioperatively from peritumoral brain parenchyma. Standard metabolites (glucose, lactate, pyruvate, glycerol and the lactate:pyruvate ratio) were quantified in relation to clinical outcome assessed by the Glasgow Coma Scale (GCS) and the Karnofsky Performance Status scale.
  
  
  RESULTS
  Higher postoperative glucose and pyruvate levels were found in patients with a favourable outcome (GCS not deteriorated or Karnofsky score > 80). Multiple logistic regression analysis (age, preoperative physical status, metabolite levels as independent variables) showed that lower postoperative glucose and pyruvate levels as well as higher lactate:pyruvate ratio values were independently associated with an unfavourable outcome as defined by Karnofsky score <80 [(OR: 0.084, 95 % CI: 0.01-0.98, p = 0.049), (OR: 0.97, 95 % CI: 0.95-0.99, p = 0.050), (OR: 1.21, 95 % CI: 1.04-1.42, p = 0.015) respectively], as well as with death [(OR: 0.08, 95 % CI: 0.01-0.97, p = 0.046), (OR: 0.94, 95 % CI: 0.89-0.99, p = 0.016), (OR: 1.07, 95 % CI: 1.00-1.15, p = 0.05) respectively].
  
  
  CONCLUSIONS
  Postoperative levels of glucose and pyruvate and the lactate:pyruvate ratio appear to correlate with clinical outcome in patients undergoing meningioma resection. The present findings provide support for the utility of microdialysis as a prognostic tool in brain tumour surgery.
authors.affiliation: Department of Anaesthesiology, Evangelismos Hospital, 66 Kosta Varnali Str., 15233, Athens, Greece, christinabalaka@yahoo.com.
authors.forename: Christina
authors.initials: C
authors.lastname: Balaka
authors.forename: George
authors.initials: G
authors.lastname: Stranjalis
authors.forename: Theodosis
authors.initials: T
authors.lastname: Kalamatianos
authors.forename: Christos
authors.initials: C
authors.lastname: Koutsarnakis
authors.forename: Triantafyllos
authors.initials: T
authors.lastname: Bouras
authors.forename: Efstathios
authors.initials: E
authors.lastname: Boviatsis
authors.forename: Damianos E
authors.initials: DE
authors.lastname: Sakas
mesh_terms: D000328:Adult; D000368:Aged; D001921:Brain / Q000378:metabolism; D005260:Female; D015600:Glasgow Coma Scale; D005947:Glucose / Q000378:metabolism; D005990:Glycerol / Q000378:metabolism; D006801:Humans; D019344:Lactic Acid / Q000378:metabolism; D008297:Male; D008577:Meningeal Neoplasms / Q000175:diagnosis / Q000378:metabolism* / Q000601:surgery; D008579:Meningioma / Q000175:diagnosis / Q000378:metabolism* / Q000601:surgery; D017551:Microdialysis; D008875:Middle Aged; D011184:Postoperative Period; D019289:Pyruvic Acid / Q000378:metabolism; D016896:Treatment Outcome
chemical_list: D019344:Lactic Acid; D019289:Pyruvic Acid; D005947:Glucose; D005990:Glycerol