Five-day partial bypass using a membrane oxygenator without systemic heparinzation

Area of Science:

• Cardiovascular Surgery
• Biomedical Engineering
• Medical Devices

Background:

• Venovenous bypass circuits are crucial for extracorporeal support.
• Systemic heparinization is often required to prevent thrombosis during bypass, posing bleeding risks.
• Current membrane oxygenators may require frequent exchange due to performance deterioration.

Purpose of the Study:

• To evaluate the efficacy and safety of a heparin-bound membrane oxygenator in a canine venovenous bypass model.
• To assess the feasibility of prolonged bypass (5 days) without systemic anticoagulation.
• To determine the impact on oxygen transfer and device performance over time.

Main Methods:

• A heparin-bound membrane oxygenator was integrated into a venovenous bypass circuit in dogs.
• Animals underwent bypass for 5 days without systemic heparinization.
• Plasma levels of SGOT and hemoglobin, along with mean linear velocity (MLW), were monitored.
• Oxygen transfer efficiency of the membrane oxygenator was assessed throughout the study period.

Main Results:

• The heparin-bound membrane oxygenator functioned effectively for 5 days in the venovenous bypass circuit.
• Plasma SGOT, plasma hemoglobin, and MLW showed transient increases post-bypass initiation but normalized.
• Oxygen transfer capabilities of the membrane oxygenator remained stable, without deterioration.
• No membrane exchange was necessary during the 5-day bypass period.

Conclusions:

• Heparin-bound membrane oxygenators can be safely utilized in venovenous bypass for up to 5 days without systemic heparinization.
• This technology mitigates the risks associated with systemic anticoagulation.
• The sustained oxygen transfer efficiency eliminates the need for intra-bypass membrane exchange, enhancing clinical applicability.