Calcium microemboli and microfilters in valve operations

Area of Science:

• Cardiovascular Surgery
• Neurology
• Pathology

Background:

• Aortic valve replacement (AVR) is a critical cardiac procedure.
• Microemboli pose a significant risk to neurological function during and after AVR.
• The efficacy of microfilters in preventing embolic events requires ongoing evaluation.

Observation:

• Three of 100 AVR patients experienced fatal microemboli.
• Two events occurred pre-microfilter era, one intraoperatively despite filter use.
• Cerebral symptoms were immediate postoperatively in all affected patients.

Findings:

• Postmortem examination confirmed cerebral calcium microemboli in 2 patients, with minute infarctions in all three brains.
• Calcium particles were detected in the kidneys of all three patients, indicating the kidneys' utility for postmortem emboli detection.
• Current microfilters are effective during extracorporeal circulation but do not prevent all emboli.

Implications:

• Surgeons must remain vigilant for embolization risks even after cardiopulmonary bypass discontinuation.
• Kidney examination is crucial for postmortem verification of calcium microemboli.
• Further strategies are needed to mitigate embolization risk during AVR, particularly in the immediate post-perfusion period.