Lipid emboli distribution in cardiac surgery is dependent on the state of emulsification.

Objective: Lipid embolizations from retransfused shed blood during cardiac surgery have been shown to enter the circulation and end up in different organs. The purpose of this investigation was to evaluate differences in the kinetics and deposition between emulsified and non-emulsified lipid emboli in a porcine model.

Design: Twelve animals were anesthetized and put on cardiopulmonary bypass. A shed-blood phantom (6 animals given emulsified and 6 given non-emulsified lipids) was produced from arterial blood, saline, and tritium-labeled triolein. The phantom was infused into the cardiopulmonary bypass circuit. Arterial and venous blood samples were taken at short intervals. Tissue samples were taken post-mortem from examined organs and prepared for scintillation counting. Levels of radioactivity were used to measure lipid emboli content in blood and tissue.

Results: Emulsified lipid emboli generated a 5-fold higher embolic load in the arterial and a 12-fold higher in the venous circulation, compared with non-emulsified lipid emboli. Emulsified lipid micro emboli resulted in a 2-15-fold higher tissue deposition in investigated organs compared with non-emulsified lipid micro emboli.

Conclusions: This study shows that the state of emulsion significantly alter the kinetics and tissue deposition of lipid emboli. Emulsified lipid emboli give higher embolic load in the arterial and venous circulation, and higher tissue deposition versus non-emulsified lipid emboli. In both groups, the embolic load was higher in the arterial circulation than on the venous side.