title: Acute Preoperative Infarcts and Poor Cerebrovascular Reserve Are Independent Risk Factors for Severe Ischemic Complications following Direct Extracranial-Intracranial Bypass for Moyamoya Disease.
abstract: OBJECTIVE
  Severe ischemic changes are a rare but devastating complication following direct superficial temporal artery to MCA bypass in patients with Moyamoya disease. This study was undertaken to determine whether preoperative MR imaging and/or cerebrovascular reserve assessment by using reference standard stable xenon-enhanced CT could predict such complications.
  
  
  METHODS
  Among all adult patients undergoing direct bypass at our institution between 2005 and 2010 who received a clinically interpretable xenon-enhanced CT examination, we identified index cases (patients with >15-mL postoperative infarcts) and control cases (patients without postoperative infarcts and without transient or permanent ischemic symptoms). Differences between groups were evaluated by using the Mann-Whitney U test. Univariate and multivariate generalized linear model regression was used to test predictors of postoperative infarct.
  
  
  RESULTS
  Six index cases were identified and compared with 25 controls. Infarct size in the index cases was 95 ± 55 mL. Four of 6 index cases (67%), but no control patients, had preoperative acute infarcts. Baseline CBF was similar, but cerebrovascular reserve was significantly lower in the index cases compared with control cases. For example, in the anterior circulation, median cerebrovascular reserve was -0.4% (range, -38.0%-16.6%) in index versus 26.3% (range, -8.2%-60.5%) in control patients (P = .003). Multivariate analysis demonstrated that the presence of a small preoperative infarct (regardless of location) and impaired cerebrovascular reserve were independent, significant predictors of severe postoperative ischemic injury.
  
  
  CONCLUSIONS
  Acute infarcts and impaired cerebrovascular reserve on preoperative imaging are independent risk factors for severe ischemic complications following superficial temporal artery to MCA bypass in Moyamoya disease.
authors.affiliation: Department of Radiology, Medical University of South Carolina, Charleston, SC.
authors.forename: Michael U
authors.initials: MU
authors.lastname: Antonucci
authors.affiliation: Department of Neurosurgery, Stanford University and Stanford University Medical Center, Stanford, CA.
authors.forename: Terrence C
authors.initials: TC
authors.lastname: Burns
authors.affiliation: Department of Radiology, Stanford University and Stanford University Medical Center, Stanford, CA.
authors.forename: T Michael
authors.initials: TM
authors.lastname: Pulling
authors.affiliation: Department of Radiology, Stanford University and Stanford University Medical Center, Stanford, CA.
authors.forename: Jarrett
authors.initials: J
authors.lastname: Rosenberg
authors.affiliation: Department of Radiology, Stanford University and Stanford University Medical Center, Stanford, CA.
authors.forename: Michael P
authors.initials: MP
authors.lastname: Marks
authors.affiliation: Department of Neurosurgery, Stanford University and Stanford University Medical Center, Stanford, CA.
authors.forename: Gary K
authors.initials: GK
authors.lastname: Steinberg
authors.affiliation: Department of Radiology, Stanford University and Stanford University Medical Center, Stanford, CA.
authors.forename: Greg
authors.initials: G
authors.lastname: Zaharchuk
mesh_terms: D000328:Adult; D000368:Aged; D002544:Cerebral Infarction / Q000209:etiology*; D002548:Cerebral Revascularization / Q000009:adverse effects* / Q000379:methods; D002560:Cerebrovascular Circulation; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009072:Moyamoya Disease / Q000601:surgery*; D015999:Multivariate Analysis; D011183:Postoperative Complications / Q000453:epidemiology / Q000209:etiology*; D012307:Risk Factors