Centrifugal or Axial LVAD? : Denis Papin versus Archimedes H. Edward Garrett, Jr., MD February 27, 2016

Implantable Ventricular Intracorporeal Implantable Ventricular Assist Devices Pulsatile Continuous Flow Axial Flow Centrifugal Flow

Disclosures HeartMate II Principal Investigator (Study Completed) XVE Registry Principal Investigator (Study Completed)

HeartMate® XVE LVAS Pneumatic driven piston pump First approved device for bridge to transplant and destination therapy Pulsatility is advantageous Disadvantages in size and durability First generation pulsatile left ventricular assist device HeartMate XVE... - Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/figure/51552937_fig1_First-generation-pulsatile-left-ventricular-assist-device-HeartMate-XVE-a-and-Thoratec [accessed Feb 15, 2016]

HeartMate II® Axial flow pump Approved for bridge to transplant and destination therapy HeartMate II left ventricular assist device and cross-sectional... - Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/figure/51552937_fig2_HeartMate-II-left-ventricular-assist-device-and-cross-sectional-internal-view [accessed Feb 15, 2016]

Axial Flow Pump Differ from radial flow in that the fluid enters and exits along the same direction parallel to the rotating shaft. The fluid is not accelerated but instead “lifted” by the action of the impeller. The pump may be likened to a propeller spinning in a length of tube.

HeartWare hVAD® System Centrifugal flow pump Approved for bridge to transplant Current study in progress for destination therapy External (a) and internal (b) view of third-generation continuous-flow... - Scientific Figure on ResearchGate. Available from: https://www.researchgate.net/figure/51552937_fig3_External-a-and-internal-b-view-of-third-generation-continuous-flow-rotary-left [accessed Feb 15, 2016]

Centrifugal Pump A rotodynamic pump that uses a rotating impeller to increase the pressure and flow rate of fluid. Most common pump used to move liquids through a piping system. Fluid enters the pump impeller along or near the rotating axis and is accelerated by the impeller, flowing radially outward or axially into a diffuser or volute chamber, then exits into the downstream piping system.

Axial flow pump attributed to Archimedes although he may have improved upon a design used to irrigate the Hanging Gardens of Babylon = http://www.bing.com/images/search?q=hanging+gardens+of+babylon&qs=AS&sk=&FORM=QBIRMH&pq=hanging&sc=8-7&sp=1&qs=AS&sk

Archimedes Born 287 B.C. in Syracuse, Sicily Killed by a Roman soldier 212 B.C. After 2 years siege at Syracuse in the Second Punic War http://www.bing.com/images/search?q=archimedes%20&qs=n&form=QBIR&pq=archimedes%20&sc=8-11&sp=-1&sk=

Contributions Archimedes principle for determining the volume of an object with irregular shape Value of π Defensive war machines like Claw and Archimedes Ray http://www.bing.com/images/search?q=Archimedes+Solar-Ray&FORM=IRIBEP http://www.bing.com/images/search?q=archimedes+mirror+weapon&qs=AS&sk=&FORM=QBIR&pq=archimedes%20mirro&sc=6-16&sp=1&qs=AS&sk=

Archimedes screw (water pump) used in largest ship built in antiquity http://www.bing.com/images/search?q=archimedes%20screw&qs=IM&form=QBIRMH&pq=archimedes%20screw&sc=8-16&sp=1&sk=

Denis Papin Born in Blois, France 1647 Died a pauper in London 1712 http://www.bing.com/images/search?q=Denis%20Papin%20&qs=n&form=QBIRMH&pq=denis%20papin%20&sc=0-0&sp=-1&sk=

Contributions Centrifugal pump Pressure cooker Steam driven paddle wheel boat http://www.bing.com/search?q=denis+papin&form=PRUSEN&mkt=en-us&refig=3f9aa7e072704afebf6f0a8dca2b3e45&filters=ufn%3A%22denis+papin%22+sid%3A%22d5bb562c-0f83-48b7-9332-c88a84bfe364%22&qs=MB&pq=denis&sc=8-5&sp=1&cvid=3f9aa7e072704afebf6f0a8dca2b3e45

Heart Mate II® Heartware hVAD® Mechanism Continuous Flow, Axial Continuous Flow, Centrifugal Operating Range (Typical range) 6,000 - 15,000 rpm (8,000 - 11,000 rpm) 2,400 - 3,200 rpm (2,400 - 2,800 rpm) Inflow Sintering Complete Partial (ring) Placement Subdiaphragmatic Intrapericardial Anti-Thrombotic Rx Asa/Coumadin BTT Approval? Yes, 2008 Yes, 2012 DT Approval Yes, 2010 No Implants Worldwide >21,000 >9,000 Goldstein DJ, Continuous Flow Left Ventricular Assist Devices: Dare to Compare, The Journal of Thoracic and Cardiovascular Surgery (2015), doi: 10. 1016/j.jtcvs.2015.09.104

Comparison of Axial vs Centrifugal Pumps Moazami N, Fukamachi K, Kobayashi M, et al: Axial and centrifugal continuous-flow rotary pumps: A translation from pump mechanics to clinical practice. J Heart Lung Transplant 32:1-11,2013

LOS CVA @ 2 years Activated coagulation and immune system Pump Thrombosis Heartmate II® 20 days 12% Higher Heartware® 16 days 28% Lower

Both Heartmate II® and Heartware hVAD ® pumps have been proven fairly equally successful with similar one year survival rates 85 – 90% Both achieve similar flow rates up to 10 L/M Similar rates of GI Bleeding occurrences

Moazami N, Fukamachi K, Kobayashi M, et al: Axial and centrifugal continuous-flow rotary pumps: A translation from pump mechanics to clinical practice. J Heart Lung Transplant 32:1-11,2013

Heartmate 3™ Now in clinical trials MOMENTUM 3 IDE Centrifugal pump with many similarities to Heartware hVAD® Bourque K, Gernes, D, Loree H, et al: HeartMate III: Pump Design for a Centrifugal LVAD with a Magnetically Levitated Rotor ASAIO J 401-405, 2001

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