Asymmetric Cerebral Embolic Load and Postoperative Cognitive Dysfunction in Cardiac Surgery

Abstract

Background: The aim of the study was to determine the effects of asymmetric cerebral embolic load on cognitive functions. Methods: Thirty-six open heart surgery (OH) and 26 coronary artery bypass grafting (CABG) patients were evaluated by neuropsychological and transcranial Doppler tests. Results: OH was associated with a significantly larger microembolic load in comparison to CABG. In OH patients, the microembolic load at the left middle cerebral artery correlated with a verbal memory decline, whereas the microembolic load at the right middle cerebral artery correlated with a nonverbal memory deficit. CABG patients also showed a postoperative verbal memory decline which correlated with cardiopulmonary bypass length but not with microembolic load. Conclusion: Massive microembolic load during OH induces specific cognitive impairment in accordance to the brain region to which they are delivered. In atherosclerotic patients, the left temporal region is especially prone to perioperative ischemia.

Asymmetric Pattern of Cerebrovascular Lesions in Patients After Left Ventricular Assist Device Implantation

“…[5][6][7][8] Considering any thrombus inside the LVAD pump as a part of cardiac embolic material in addition to actual intracardiac thrombi, right-to-left propensity of stroke after LVAD can be easily explained by anatomic alignment of the arteries arising from aortic arch. Moreover, surgical manipulation of LVAD outflow cannula-to-ascending aorta anastomosis may also direct embolic material toward the brachiocephalic trunk.…”

“…2,4 Cerebral embolic events after cardiac surgery are frequently distributed more often in the right cerebral hemisphere. [5][6][7] Kim et al 8 reported recently that right hemispheric infarcts are associated with cardiogenic embolism, whereas left hemispheric infracts are more associated with aortogenic embolism. In the present study, we investigated the distribution of stroke in patients undergoing LVAD implantation and whether clinical characteristics differed in LVAD patients experiencing right versus left hemispheric stroke.…”

Cognitive Dysfunction after On-Pump Operations: Neuropsychological Characteristics and Optimal Core Battery of Tests

“…In our original study which using intraoperative transcranial doppler monitoring [56], we registered significant linear correlations between the intraoperative microembolic load on the left hemisphere and postoperative decline of performance on digit span forward, but we did not observe this on the “word-list learning” or “story learning” tests. In addition, we observed significant correlations between intraoperative microembolic loads on the right hemisphere and a decline on “nonverbal memory” tests.…”

Occurrence and Clinical Impact of Microembolic Signals During or After Cardiosurgical Procedures

“…Whereas some study groups described a preponderance of left-sided MESs, 50,90 others either reported an equal distribution of MESs 91 or found a preference for the right hemisphere. 49,51 In conclusion, MESs are a common phenomenon during cardiac surgery. The composition of the microemboli is heterogeneous and reflects solid and gaseous particles.…”

“…Interestingly, a specific verbal memory decline in patients with predominantly left-sided MESs was observed, whereas a higher number of right-sided MESs was associated with a nonverbal memory deficit after open-heart surgery. 51 The correlation of a high number of MESs, particularly during on-pump cardiac surgery, with a relative reduction of prefrontal activation during functional magnetic resonance imaging while performing verbal memory tasks 4 weeks postoperatively could also be demonstrated. 52 There are additional reports on cognitive impairment and delayed recovery after CABG due to intraoperative MESs.…”