title: Rapid resolution of brain ischemic hypoxia after cerebral revascularization in moyamoya disease.
abstract: BACKGROUND
  In moyamoya disease (MMD), cerebral revascularization is recommended in patients with recurrent or progressive ischemic events and associated reduced cerebral perfusion reserve. Low-flow bypass with or without indirect revascularization is generally the standard surgical treatment. Intraoperative monitoring of cerebral partial pressure of oxygen (PtiO2) with polarographic Clark-type probes in cerebral artery bypass surgery for MMD-induced chronic cerebral ischemia has not yet been described.
  
  
  OBJECTIVE
  To describe basal brain tissue oxygenation in MMD patients before revascularization as well as the immediate changes produced by the surgical procedure using intraoperative PtiO2 monitoring.
  
  
  METHODS
  Between October 2011 and January 2013, all patients with a diagnosis of MMD were intraoperatively monitored. Cerebral oxygenation status was analyzed based on the Ptio2/PaO2 ratio. Reference thresholds of PtiO2/PaO2 had been previously defined as below 0.1 for the lower reference threshold (hypoxia) and above 0.35 for the upper reference threshold (hyperoxia).
  
  
  RESULTS
  Before STA-MCA bypass, all patients presented a situation of severe tissue hypoxia confirmed by a PtiO2/PaO2 ratio <0.1. After bypass, all patients showed a rapid and sustained increase in PtiO2, which reached normal values (PtiO2/PaO2 ratio between 0.1 and 0.35). One patient showed an initial PtiO2 improvement followed by a decrease due to bypass occlusion. After repeat anastomosis, the patient's PtiO2 increased again and stabilized.
  
  
  CONCLUSIONS
  Direct anastomosis quickly improves cerebral oxygenation, immediately reducing the risk of ischemic stroke in both pediatric and adult patients. Intraoperative PtiO2 monitoring is a very reliable tool to verify the effectiveness of this revascularization procedure.
authors.affiliation: *Department of Neurosurgery and the Neurotraumatology and Neurosurgery Research Unit (UNINN); ‡Departments of Anesthesiology and §Nuclear Medicine, Vall d'Hebron University Hospital, Universitat Autònoma de Barcelona, Barcelona, Spain.
authors.forename: Fuat
authors.initials: F
authors.lastname: Arikan
authors.forename: Jordi
authors.initials: J
authors.lastname: Vilalta
authors.forename: Ramon
authors.initials: R
authors.lastname: Torne
authors.forename: Montserrat
authors.initials: M
authors.lastname: Noguer
authors.forename: Carles
authors.initials: C
authors.lastname: Lorenzo-Bosquet
authors.forename: Juan
authors.initials: J
authors.lastname: Sahuquillo
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000098:blood supply* / Q000601:surgery; D002548:Cerebral Revascularization / Q000379:methods*; D002648:Child; D002675:Child, Preschool; D005260:Female; D006801:Humans; D000860:Hypoxia; D064795:Intraoperative Neurophysiological Monitoring / Q000379:methods*; D008297:Male; D008875:Middle Aged; D009072:Moyamoya Disease / Q000503:physiopathology* / Q000601:surgery*; D010100:Oxygen / Q000032:analysis; D010313:Partial Pressure; D055815:Young Adult
chemical_list: D010100:Oxygen