Twenty-four hour membrane oxygenation in dogs without anticoagulation

Area of Science:

• Cardiovascular Surgery
• Biomaterials Science
• Hematology

Background:

• Cardiopulmonary bypass (CPB) requires anticoagulation to prevent thrombosis.
• Systemic heparinization and heparin-bonded circuits are common anticoagulation strategies.
• The optimal anticoagulation strategy for CPB remains under investigation.

Purpose of the Study:

• To compare the efficacy of no anticoagulation, systemic heparinization, and heparin-bonded circuitry during 24-hour CPB in a canine model.
• To evaluate effects on survival, hemodynamics, coagulation, oxygenator function, and circuit integrity.

Main Methods:

• A prospective study involving three groups of five dogs each undergoing 24-hour CPB.
• Group I: No anticoagulation; Group II: Systemic heparinization; Group III: Heparin-bonded circuits.
• Parameters assessed included blood pressure, coagulation status, oxygenator function, and SEM of circuit surfaces.

Main Results:

• Survival rates were 100% (no anticoagulation), 80% (heparinization), and 20% (heparin-bonded circuits).
• Arterial pressures were better maintained in the no anticoagulation group.
• Coagulation parameters and oxygenator function were similar across groups; no thrombi were found in circuits, but Group I surfaces had less debris.

Conclusions:

• Systemic heparinization offered no advantage over no anticoagulation in this study.
• Heparin-bonded circuits were found to be unsatisfactory compared to no anticoagulation.
• Further research is needed to establish optimal anticoagulation guidelines for human CPB.