Reduction of gaseous microembolism during aortic valve replacement using a dynamic bubble trap

Area of Science:

• Cardiovascular Surgery
• Neurology
• Biomedical Engineering

Background:

• Gaseous microbubbles in extracorporeal circulation (ECC) contribute to postoperative psycho-neurological dysfunction.
• Reducing microbubble load during cardiac surgery is crucial for patient outcomes.

Purpose of the Study:

• To evaluate the efficacy of a dynamic bubble trap (DBT) in reducing microbubble load during ECC.
• To assess the impact of DBT on high-intensity transient signals (HITS) in the middle cerebral artery.

Main Methods:

• Prospective randomized double-blind study with 41 patients undergoing aortic valve replacement.
• Patients were assigned to a group with a DBT or a placebo-DBT in the arterial line.
• Doppler ultrasonography monitored microbubbles and HITS in the middle cerebral artery during ECC.

Main Results:

• The DBT group showed a significant reduction in microbubble load during ECC (p < 0.0001).
• A significant difference in HITS was observed between groups during the cross-clamp period (P1) (p < 0.002 left, p < 0.005 right MCA).
• DBT did not eliminate HITS after aortic declamping (P2) due to potential air entry into supra-aortal vessels.

Conclusions:

• Dynamic bubble traps effectively reduce microbubble load and HITS during the cross-clamped phase of ECC in aortic valve replacement.
• DBT use is justified in open chamber surgery to mitigate embolic events during ECC.
• DBT cannot replace meticulous venting procedures after aortic declamping.