In Vitro Evaluation of Ventricular Cannulation for Rotodynamic Cardiac Assist Devices
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The influence of positioning and geometry of ventricular cannulas for contemporary continuous flow Left Ventricular Assist Devices (LVADs) was evaluated in a non-beating isolated heart preparation with borescopic visualization. Preload and LVAD flow were varied to evaluate degrees of ventricular decompression up to the point of ventricular collapse. The performance of a flanged cannula was compared to a conventional bevel-tipped cannula: quantitatively by the maximal flow attainable, and qualitatively by visualization of fluid tracer particles within the ventricular chamber. Three forms of ventricular suck-down occurred: concentric collapse, gradual entrainment and instantaneous entrainment. In some circumstances, unstable oscillations of the ventricle were observed prior to complete collapse. Under conditions of low preload, the flanged cannula demonstrated less positional sensitivity, provided greater flow, and exhibited fewer areas of stagnation than the beveled cannula. These observations warrant further consideration of a flanged ventricular cannula to mitigate complications encountered with conventional cannulae.
KeywordsVentricular cannula Ventricular assist device Rotary blood pump Hemodynamics
The authors would like to thank Arielle Drummond, PhD; and Fangjun Shu, PhD; for their assistance with the development of the isolated heart preparation. The Authors would also like to thank Harvey Borovetz, PhD for his support. Financial support was provided by an STTR Grant from the National Institute of Health 1R41HL082251-01.
Conflict of interest
At the time of the study, Josiah Verkaik was employed by LaunchPoint technologies, Inc. All remaining authors have no disclosures to report.
Movie 1- Borescopic and transepicardial echocardiographic long-axis view of concentric ventricular collapse and resulting oscillation generated using aligned flared cannula. (MPG 11581 kb)
Movie 2- Borescopic view of instantaneous ventricular entrainment and resulting oscillation generated using misaligned flared cannula. (MPG 10705 kb)
Movie 3- Borescopic and transepicardial echocardiographic long-axis view of concentric ventricular collapse generated using aligned beveled cannula. (MPG 10705 kb)
Movie 4- Borescopic view of gradual ventricular entrainment and resulting oscillation generated using misaligned beveled cannula. Movie was recorded at 4x normal speed. (MPG 11429 kb)
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