title: Short-term in vivo studies of surface thrombosis in a left ventricular assist system.
abstract: Thrombosis continues to be a major adverse and at times fatal event in patients with left ventricular assist systems (LVAS). To assess acute thrombosis in an LVAS, multiscale analysis of surface thrombosis was performed on LVAS blood sacs retrieved after implantation in seven calves for 3 days. Two study groups were evaluated: One group was given heparin and warfarin sodium throughout the study; the second received no postoperative anticoagulation. On explantation, the blood sacs were examined for macroscopic thrombi; microscale thrombosis was assessed with the use of scanning electron microscopy. Macroscopic thrombi about 1 mm in diameter were seen in all sacs from both groups. Although macroscopic thrombi occurred in all sac regions, scanning electron microscopy revealed differences in microscale topography between the port regions and the other sac regions. The primary structure was spherical particles approximately 400 nm in diameter, found to occur at a lower density in the ports. In contrast, the highest densities of proteinaceous rough topography and fibrillar structures consistent with fibrin clot were seen in the port regions. The density distribution of these structures was different in the eight sac regions, and anticoagulation therapy appeared to have no effect on surface thrombosis in these short-term LVAS implants.
authors.affiliation: Department of Bioengineering, The Pennsylvania State University, Hershey, Pennsylvania 17033, USA.
authors.forename: Hanako
authors.initials: H
authors.lastname: Yamanaka
authors.forename: Gerson
authors.initials: G
authors.lastname: Rosenberg
authors.forename: William J
authors.initials: WJ
authors.lastname: Weiss
authors.forename: Alan J
authors.initials: AJ
authors.lastname: Snyder
authors.forename: Conrad M
authors.initials: CM
authors.lastname: Zapanta
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Siedlecki
mesh_terms: D000208:Acute Disease; D000818:Animals; D000925:Anticoagulants / Q000627:therapeutic use; D001783:Blood Flow Velocity; D002417:Cattle; D004867:Equipment Design; D006353:Heart-Assist Devices / Q000009:adverse effects*; D006493:Heparin / Q000627:therapeutic use; D020007:Implants, Experimental; D007700:Kinetics; D008855:Microscopy, Electron, Scanning; D049329:Nanostructures / Q000648:ultrastructure; D010316:Particle Size; D011184:Postoperative Period; D033081:Shear Strength; D013499:Surface Properties / Q000187:drug effects; D013927:Thrombosis / Q000188:drug therapy / Q000209:etiology* / Q000662:veterinary*; D013997:Time Factors; D016277:Ventricular Function, Left / Q000502:physiology*; D014859:Warfarin / Q000627:therapeutic use
chemical_list: D000925:Anticoagulants; D014859:Warfarin; D006493:Heparin