Improved hydrodynamics of a new aortic cannula with a novel tip design

Abstract

Background: Reduction of atheroembolic complications during cardiopulmonary bypass remains a major challenge in cardiac surgery. New cannula tip designs may help to attenuate this problem by improved hydrodynamics.

Methods: Pressure gradients and back pressures of a new aortic cannula tip design were measured and compared with the Medos X-Flow, Sarns Soft-Flow and Argyle THI cannulae at various flow rates in a mock circulation followed by flow visualization.

Results: Pressure gradients were the lowest for the new cannula. Back pressures of the new cannula were up to 84% lower than for the Argyle cannula. The back pressure profile and flow visualization of the new cannula showed broad centric flow dispersion with a transcannula increase of flow area from 38 mm² to 139 mm².

Conclusions: The new design of an aortic cannula tip provides improved hydrodynamics, with low pressure gradients, low back pressures and a uniform central dispersion of flow, reducing the sandblasting effect.

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