Related Experiment Videos
Calcium microemboli and microfilters in valve operations
Insights
Fatal microemboli during aortic valve replacement can cause severe brain damage. Kidneys are the best organ for detecting calcium emboli postmortem, even when cerebral emboli are not confirmed.
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.
Abstract:
Fatal microemboli occurred in 3 of 100 consecutive patients having aortic valve replacement; 2 occurred during perfusion before the microfilter era, and 1 occurred intraoperatively despite the use of in-line filters. In all 3 patients cerebral symptoms were present immediately postoperatively, and each died of severe brain damage. On postmortem examination cerebral calcium microemboli were verified in only 2 patients, although the brain of each patient contained minute infarctions. However, calcium particles were found in the kidneys of all 3 patients. Thus the kidneys proved to be the best place for detection of calcium emboli on postmortem examination. Although the microfilters currently available effectively prevent microemboli during extracorporeal circulation, the surgeon should be aware that embolization can also occur immediately after discontinuation of perfusion. The means of protecting the patient from this are discussed.