An Optimized Multi-Stage Drainage Cannula Design for Venoarterial Extracorporeal Membrane Oxygenation

Area of Science:

• Biomedical Engineering
• Cardiovascular Physiology
• Medical Device Design

Background:

• Venoarterial extracorporeal membrane oxygenation (VA ECMO) is vital for cardiogenic shock patients.
• Current VA ECMO drainage cannulas cause complications like thrombosis and hemolysis due to altered flow dynamics.

Purpose of the Study:

• To develop an optimized VA ECMO drainage cannula design using computational fluid dynamics (CFD).
• To reduce the risk of complications associated with VA ECMO therapy.

Main Methods:

• A multi-objective optimization process involved 540 unique cannula designs.
• Objective functions included minimizing pressure drop, maintaining tip velocity (>100 mm/s), and minimizing wall shear stress.
• The optimized design was validated in patient-specific geometries and compared to a clinical model.

Main Results:

• The optimized cannula features three rows of five side holes, each angled at 31.5°.
• Compared to the clinical model, it generated lower stagnant blood volumes and higher tip velocities (>300 mm/s).
• Improved drainage from the upper body was observed.

Conclusions:

• The optimized cannula design exhibits favorable flow dynamics.
• This design may reduce thrombosis and hemolysis risks in clinical VA ECMO applications.
• Improved patient outcomes are anticipated with this enhanced cannula.