The effects of cardiopulmonary bypass on the number of cerebral microemboli and the incidence of cognitive dysfunction after coronary artery bypass graft surgery

Anesth Analg. 2009 Oct;109(4):1013-22. doi: 10.1213/ane.0b013e3181aed2bb.


Background: Postoperative cognitive dysfunction (POCD) can be a debilitating complication after coronary artery bypass graft (CABG) surgery. Cerebral microemboli during cardiopulmonary bypass (CPB) are believed to be an important etiologic factor of POCD. In this study, we examined whether avoidance of CPB with "off-pump" surgery reduces the number of cerebral microemboli and the incidence of POCD after CABG surgery in Chinese population.

Methods: Two hundred twenty-seven patients were enrolled in this prospective cohort study. Fifty-nine patients underwent CABG surgery with CPB and 168 underwent off-pump surgery. Cerebral microemboli were measured continuously with bilateral transcranial Doppler ultrasonography of the middle cerebral arteries. A neuropsychological test battery that included seven tests with nine subscales was administered at baseline, as well as at 1 wk and 3 mo after surgery. POCD was defined using the international study of POCD1 definition.

Results: The median total number of cerebral microemboli for the case was 430 (range: 155-2088) in patients undergoing surgery with CPB and 2 (0-66) in the off-pump patients (P < 0.001). There were no differences in the incidence of POCD between the patients having surgery with or without CPB either at 1 wk (55.2% or 32 of 58 patients [95% confidence interval: 41.5%-68.3%] vs 47.0% or 78 of 166 patients [39.2%-54.9%], P = 0.283) or 3 mo (6.4% or 3 of 47 patients [1.3%-17.5%] vs 13.1% or 16 of 122 of patients [7.7%-20.4%], P = 0.214) after surgery. Increasing age and shorter duration of postoperative hospital stay were independently associated with cognitive dysfunction at 1 wk after surgery. Increasing age and a history of diabetes mellitus were independently associated with cognitive dysfunction 3 mo after surgery. CPB or cerebral microemboli were not significantly related to the occurrence of POCD.

Conclusions: In Chinese population, avoidance of CPB during CABG surgery significantly decreased the number of cerebral microemboli, but it did not decrease the incidence of POCD at either 1 wk or 3 mo after CABG. Neither CPB nor cerebral microemboli was independently associated with the risk of POCD.

Publication types

  • Comparative Study
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Age Factors
  • Aged
  • Asian Continental Ancestry Group
  • Cardiopulmonary Bypass / adverse effects*
  • Cardiopulmonary Bypass / mortality
  • China
  • Cognition Disorders / diagnosis
  • Cognition Disorders / ethnology
  • Cognition Disorders / etiology*
  • Cognition Disorders / prevention & control
  • Coronary Artery Bypass / adverse effects*
  • Coronary Artery Bypass / mortality
  • Coronary Artery Bypass, Off-Pump / adverse effects*
  • Coronary Artery Bypass, Off-Pump / mortality
  • Diabetes Complications / etiology
  • Female
  • Humans
  • Incidence
  • Intracranial Embolism / diagnostic imaging
  • Intracranial Embolism / ethnology
  • Intracranial Embolism / etiology*
  • Intracranial Embolism / prevention & control
  • Length of Stay
  • Logistic Models
  • Male
  • Middle Aged
  • Neuropsychological Tests
  • Prospective Studies
  • Risk Assessment
  • Risk Factors
  • Stroke / etiology
  • Time Factors
  • Treatment Outcome
  • Ultrasonography, Doppler, Transcranial