Perioperative microdialysis in meningioma surgery: correlation of cerebral metabolites with clinical outcome.

Abstract

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. 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. 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]. 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.