Immunochemical identification of human endothelial cells on the lining of a ventricular assist device.
We are studying the biologic (pseudointimal) lining that forms in the HeartMate (Thermo Cardiosystems, Inc.; Woburn, Massachusetts, USA), a left ventricular assist device with a pusher-plate blood pump, housed in solid titanium with uniquely textured blood-contacting surfaces. Sintered titanium microspheres cover the rigid surface, and integrally textured polyurethane lines the flexing diaphragm. The texture of the blood-contacting surfaces is designed to encourage formation of a biologic pseudointimal lining, which greatly reduces the risk of thromboembolic complications. We performed immunochemical analyses to characterize precisely the pseudointimal lining. Samples were taken from 2 explanted pumps; 1 had supported a patient for 132 days and the other, 189 days. The samples were cultured to detect factor-VIII-related antigen (von Willebrand factor), acetyl low-density lipoprotein receptors, smooth-muscle-cell actin, and surface adhesion molecules specific for monocytes/macrophages. Macrophage cells were predominant in both pumps, but in the 2nd pump, cultures from the center of the diaphragm were positive for acetyl low-density lipoprotein receptor and von Willebrand factor, indicating the presence of endothelial cells. We believe that blood-borne endothelial cells or endothelial cell precursors were deposited on the blood-contacting surfaces, which is an important clinical finding with regard to lowering the risk of thromboembolic complications and reducing the need for systemic anticoagulation in long-term left ventricular assist device patients.
Frazier
O H
OH
Department of Cardiovascular Surgery, Texas Heart Institute, Houston 77225-0345.
Baldwin
R T
RT
Eskin
S G
SG
Duncan
J M
JM
D000199:Actins / Q000032:analysis; D000328:Adult; D002478:Cells, Cultured; D004727:Endothelium / Q000737:chemistry / Q000166:cytology*; D006353:Heart-Assist Devices; D006801:Humans; D007150:Immunohistochemistry; D008074:Lipoproteins; D008264:Macrophages / Q000166:cytology / Q000276:immunology; D008297:Male; D008875:Middle Aged; D011956:Receptors, Cell Surface / Q000032:analysis; D018110:Receptors, Lipoprotein; D013499:Surface Properties; D014841:von Willebrand Factor / Q000032:analysis
D000199:Actins; D008074:Lipoproteins; D011956:Receptors, Cell Surface; D018110:Receptors, Lipoprotein; D014841:von Willebrand Factor