title: Risk of surgery and anesthesia for ischemic stroke.
abstract: BACKGROUND
  The goal of this study was to determine if the combination of surgery and anesthesia is an independent risk factor for the development of incident (first-time) ischemic stroke.
  
  
  METHODS
  All residents of Rochester, MN, with incident ischemic stroke from 1960 through 1984 (1,455 cases and 1,455 age- and gender-matched controls) were used to identify risk factors associated with ischemic stroke. Cases and controls undergoing surgery involving general anesthesia or central neuroaxis blockade before their stroke/index date of diagnosis were identified. A conditional logistic regression model was used to estimate the odds ratio of surgery and anesthesia for ischemic stroke while adjusting for other known risk factors.
  
  
  RESULTS
  There were 59 cases and 17 controls having surgery within 30 days before their stroke/index date. After adjusting for previously identified risk factors, surgery within 30 days before the stroke/index date (perioperative period) was found to be an independent risk factor for stroke (P<0.001; odds ratio, 3.9; 95% confidence interval, 2.1-7.4). In an analysis that excluded matched pairs where the case and/or control underwent surgery considered "high risk" for stroke (cardiac, neurologic, or vascular procedures), "non-high-risk surgery" was also found to be an independent risk factor for perioperative stroke (P = 0.002; odds ratio, 2.9; 95% confidence interval, 1.5-5.7).
  
  
  CONCLUSIONS
  Our results suggest that there is an increased risk of ischemic stroke in the 30 days after surgery and anesthesia. This risk remains elevated even after excluding surgeries (cardiac, neurologic, and vascular surgeries) considered to be high risk for ischemic stroke.
authors.affiliation: Department of Anesthesiology, Mayo Clinic and Foundation, Rochester, Minnesota 55905, USA. wong.gilbert@mayo.edu
authors.forename: G Y
authors.initials: GY
authors.lastname: Wong
authors.forename: D O
authors.initials: DO
authors.lastname: Warner
authors.forename: D R
authors.initials: DR
authors.lastname: Schroeder
authors.forename: K P
authors.initials: KP
authors.lastname: Offord
authors.forename: M A
authors.initials: MA
authors.lastname: Warner
authors.forename: P M
authors.initials: PM
authors.lastname: Maxson
authors.forename: J P
authors.initials: JP
authors.lastname: Whisnant
mesh_terms: D000368:Aged; D000704:Analysis of Variance; D000758:Anesthesia / Q000009:adverse effects*; D016022:Case-Control Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D008910:Minnesota / Q000453:epidemiology; D016017:Odds Ratio; D012044:Regression Analysis; D012307:Risk Factors; D012907:Smoking / Q000503:physiopathology; D020521:Stroke / Q000453:epidemiology*; D013514:Surgical Procedures, Operative / Q000009:adverse effects*