Design optimization of bidirectional arterial perfusion cannula.

Area of Science:

• Cardiovascular Surgery
• Biomedical Engineering
• Extracorporeal Life Support

Background:

• Lower limb ischemia is a risk during long-term extracorporeal life support (ECLS) with peripheral cannulation.
• Bidirectional arterial cannulas are used to provide arterial return in ECLS.
• Optimizing cannula design is crucial for patient safety and outcomes.

Purpose of the Study:

• To evaluate the impact of a shorter covered section on the performance of a self-expanding bidirectional arterial cannula.
• To determine if reduced coverage enhances retrograde flow and potentially mitigates lower limb ischemia.

Main Methods:

• Outlet pressure and flow rate were measured for three cannula types: 90 mm covered, 60 mm covered bidirectional cannulas, and a control Biomedicus cannula.
• A computerized flow-bench with calibrated sensors and a centrifugal pump was utilized.
• Retrograde flow was assessed using a tank timer technique at varying pump speeds.

Main Results:

• Both bidirectional cannulas outperformed the control, exhibiting higher flow rates and lower pressures.
• The 60 mm covered bidirectional cannula demonstrated superior performance compared to the 90 mm covered version.
• The experimental setup provided consistent measurements with low variability.

Conclusions:

• A shorter covered section (60 mm) in self-expanding bidirectional arterial cannulas improves hemodynamic performance.
• This modified cannula design offers a potential solution to reduce lower limb ischemia in long-term ECLS.
• Further clinical investigation is warranted to confirm these findings in patients.