[Microembolizatoins during heart surgery under extracorporeal circulation].
OBJECTIVE
By means of transcranial Doppler sonography (TCD), microembolic signals (MES) representing embolic events can be registered during cardiac surgery and extracorporeal circulation in a considerable number of patients. We conducted the present study to determine the neuro-psychiatric consequences of MES.


METHODS
25 patients scheduled for elective aorto-coronary bypass grafting (ACBG; n = 10) or aortic valve replacement (AVR; n = 15) were studied pre- and postoperatively with neuropsychiatric testing. Results were related to the number of MES noted intraoperatively. In addition, we registered the intraoperative changes of middle cerebral artery blood flow velocity, mean arterial pressure, arterial blood gases, haemoglobin and haematocrit. Statistics included t-test, two-way analysis of variance, Mann-Whitney-U-test and Spearman correlation with p < 0.05 considered significant.


RESULTS
Regarding demographic data and intraoperative parameters, both study groups (ACBG vs. AVR) were comparable except for age. AVR patients showed significantly more MES than those undergoing ACBG (p < 0.012) which was most pronounced in the late state of surgery (aortic clamp off; p < 0.0003). However, MES counts did not correlate with neuropsychiatric test results.


CONCLUSIONS
In contrast to recent reports, we were unable to show a deterioration of postoperative neuropsychiatric state related to high intraoperative MES count in our patients. Future TCD studies should focus on the differentiation between gaseous emboli and particles even in the clinical setting, as the latter may well play a major role for the development of cerebral dysfunction following cardiac surgery and extracorporeal circulation.
Thiel
A
A
Abteilung Anaesthesiologie und operative Intensivmedizin am Ostalbklinikum Aalen.
Zimmer
M
M
Stertmann
W A
WA
Kaps
M
M
Hempelmann
G
G
D000704:Analysis of Variance; D000768:Anesthesia, General; D001783:Blood Flow Velocity; D002560:Cerebrovascular Circulation; D001026:Coronary Artery Bypass / Q000009:adverse effects*; D005112:Extracorporeal Circulation / Q000009:adverse effects*; D019918:Heart Valve Prosthesis Implantation; D006801:Humans; D002542:Intracranial Embolism and Thrombosis / Q000000981:diagnostic imaging / Q000209:etiology* / Q000523:psychology; D008875:Middle Aged; D016343:Monitoring, Intraoperative; D009483:Neuropsychological Tests; D018709:Statistics, Nonparametric; D017585:Ultrasonography, Doppler, Transcranial
Mikroembolisation während Herzoperationen unter extrakorporaler Zirkulation.