title: Measurement of cortical microcirculation during intracranial aneurysm surgery by combined laser-Doppler flowmetry and photospectrometry.
abstract: BACKGROUND
  Accidental vessel occlusion is one major risk of intracranial aneurysm surgery potentially causing cerebral ischemia. The intraoperative assessment of cerebral ischemia remains a technological challenge.
  
  
  OBJECTIVE
  As a novel approach, cortical tissue integrity was monitored using simultaneous measurements of regional capillary-venous cerebral blood flow (rvCBF), oxygen saturation (Srvo2), and hemoglobin amount (rvHb) during aneurysm surgery.
  
  
  METHODS
  Fifteen patients scheduled for aneurysm surgery of the anterior and posterior circulation were included. A fiber optic probe was placed on the cortex associated with the distal branch of the aneurysmatic vessel. Blinded measurements by combined laser-Doppler flowmetry (rvCBF) and photospectrometry (Srvo2, rvHb) were performed before and after surgical clipping or trapping of the aneurysm. Data were correlated with postoperative imaging and neurological outcome.
  
  
  RESULTS
  Cortical measurements could be successfully performed in all patients. Significant increase (>25% change from baseline) or decrease (<25% change from baseline) of rvCBF, Srvo2, and rvHb was detectable in 33 to 46% of patients after surgical intervention. Severe decrease (>50% change from baseline) of all parameters or solitary of rvCBF was correlated to reduced cerebral perfusion and neurological deficits in 2 patients.
  
  
  CONCLUSIONS
  Combined laser-Doppler flowmetry and photospectrometry provides real-time information on cortical microcirculation. Intraoperative alterations of parameters (rvCBF, Srvo2, rvHb) might reflect changes of cerebral tissue integrity during intracranial aneurysm surgery.
authors: Department of Anesthesiology, Medical Center of Johannes Gutenberg-University, Mainz, Germany. kuklein@uni-mainz.de
authors: Klaus Ulrich
authors: KU
authors: Klein
authors: Axel
authors: A
authors: Stadie
authors: Kimiko
authors: K
authors: Fukui
authors: Patrick
authors: P
authors: Schramm
authors: Christian
authors: C
authors: Werner
authors: Joachim
authors: J
authors: Oertel
authors: Kristin
authors: K
authors: Engelhard
authors: Gerrit
authors: G
authors: Fischer
mesh_terms: D000328:Adult; D000368:Aged; D002545:Brain Ischemia / Q000517:prevention & control; D002540:Cerebral Cortex / Q000098:blood supply* / Q000601:surgery*; D002560:Cerebrovascular Circulation / Q000502:physiology; D057510:Endovascular Procedures / Q000009:adverse effects; D005240:Feasibility Studies; D005260:Female; D006801:Humans; D002532:Intracranial Aneurysm / Q000601:surgery*; D017078:Laser-Doppler Flowmetry / Q000379:methods*; D008297:Male; D008833:Microcirculation / Q000502:physiology; D008875:Middle Aged; D016343:Monitoring, Intraoperative / Q000379:methods*; D019635:Neurosurgical Procedures / Q000009:adverse effects; D013057:Spectrum Analysis