A retrospective observational clinical study.
A single-center regional hospital.
Fifty-five patients undergoing elective cardiac surgery with CPB.
Bilateral detection of the patients' middle cerebral arteries using a multifrequency transcranial Doppler.
Patients were divided into 3 groups depending on the CPB circuit used (open, open with vacuum, or closed). There was a significant difference between the number of solid and gaseous microemboli (p<0.001), with the solid lower than the gaseous ones. The number of solid microemboli was affected by group (p< 0.05), CPB phase (p<0.001), and laterality (p<0.01). The number of gaseous microemboli was affected only by group (p<0.05) and CPB phase (p<0.001). Generally, the length of CPB phase did not affect the number of microemboli.
Surgical procedures combined with CPB circuits, but not the CPB phase length, affected the occurrence, nature, and laterality of microemboli.