Improved flow straighteners reduce thrombus in the NASA/DeBakey axial flow ventricular assist device.
A small axial flow ventricular assist device (VAD) measuring 3 inches long and 1 inch in diameter is in development. The pump consists of a spinning inducer/ impeller, a flow straightener (FLS), and a diffuser enclosed in a cylindrical flow tube. The impeller has rod-shaped permanent magnets embedded within its 6 blades and is activated magnetically by the motor stator which is positioned outside the flow tube. At the completion of a previous study, the FLS was identified as a thrombogenic area. The aim of the present study was to evaluate the thrombogenicity of redesigned FLSs (swept-back and bulbous types), compared with standard type (STD) FLS. A total of 15 pumps (STD, n = 7; swept-back, n = 4; and bulbous, n = 4) were sequentially implanted into 4 calves paracorporeally in a short-term ex vivo test. The STD and bulbous FLSs experienced thrombus formation, but the swept-back FLS was thrombus free during a 48 h screening test.
Kawahito
K
K
Department of Surgery, Baylor College of Medicine, Houston, Texas 77030, USA.
Benkowski
R
R
Ohtsubo
S
S
Noon
G P
GP
Nosé
Y
Y
DeBakey
M E
ME
D000704:Analysis of Variance; D000818:Animals; D002417:Cattle; D004058:Diffusion; D006353:Heart-Assist Devices / Q000592:standards* / Q000639:trends; D006461:Hemolysis; D066298:In Vitro Techniques; D011673:Pulsatile Flow; D013927:Thrombosis / Q000517:prevention & control*; D014481:United States; D018557:United States National Aeronautics and Space Administration