Thrombus formation and microaggregate removal during prolonged extracorporeal circulation using a capillary membrane...

Area of Science:

• Biomaterials Science
• Medical Devices
• Cardiovascular Surgery

Background:

• Thrombus formation at the blood/foreign material interface is a known complication during extracorporeal circulation, even with adequate heparinization.
• These thrombi can embolize, leading to potential organ damage in the lungs, brain, kidneys, and retina.
• The composition and extent of thrombus formation vary based on device components, materials, and blood flow dynamics.

Purpose of the Study:

• To investigate the efficacy of incorporating filters in preventing embolic events during prolonged extracorporeal circulation.
• To analyze thrombus formation within the Awad oxygenator using scanning electron microscopy.
• To compare the effects of different filter types (screen filter vs. polyurethane foam filter) on thrombus characteristics.

Main Methods:

• A scanning electron microscope study was conducted on the Awad oxygenator after use in 13 dogs undergoing prolonged extracorporeal circulation.
• Initial experiments (6 dogs) were performed without an interposition filter.
• Subsequent experiments utilized either a screen filter or a polyurethane foam filter within the circuit.

Main Results:

• Thrombus formation was observed at the blood/foreign material interface in the Awad oxygenator.
• The presence and characteristics of thrombi varied depending on whether a filter was used and the type of filter employed.
• Filters appeared to mitigate the risk of clot embolization downstream.

Conclusions:

• Interposition of filters in extracorporeal circulation circuits, specifically with the Awad oxygenator, shows promise in preventing embolic risks.
• Filter integration may reduce the potential for downstream organ damage caused by embolized thrombi.
• Further research into optimal filter design and placement is warranted for enhanced patient safety.