Scanning and transmission electron microscopic evaluation of the U-100 total artificial heart blood contacting surface.
Thrombus formation, cell adhesion, mineralization, and the adsorbed protein layer have been investigated on blood contacting surfaces of the Utah-100 total artificial heart (TAH). Retrieval analysis was performed on two calves (at 7 and 97 days) and a sheep (at 21 days). Six locations on each ventricle were systematically evaluated by scanning electron microscopy. Transmission electron microscopy was used to measure the thickness and distribution of proteins (albumin, IgG, and fibrinogen) on the surface. Gross thrombus was detected only on the left atrial cuff in the 97 day calf. SEM demonstrated fairly clear surface morphology, with minimal platelet adhesion and activation, and little thrombus formation. At 97 days, calcium deposits were detected along the diaphragm-housing junction. Protein layer thickness on the diaphragm increased with implant time; dominant proteins detected on the surface were fibrinogen and IgG, rather than albumin. Improvements in design and fabrication techniques have demonstrated decreased intradevice thrombosis with the U-100 TAH. However, systemic thromboembolism still remains a problem, and further improvements in the blood contacting surface of the U-100 TAH are necessary to achieve a thrombus free TAH.
Nojiri
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C
Department of Pharmaceutics Center for Controlled Chemical Delivery (CCCD), University of Utah, Salt Lake City 84108.
Kim
S W
SW
Jacobs
H A
HA
Pantalos
G M
GM
Olsen
D B
DB
D000818:Animals; D002417:Cattle; D005340:Fibrinogen / Q000032:analysis; D006041:Goats; D006354:Heart, Artificial; D007124:Immunoenzyme Techniques; D007074:Immunoglobulin G / Q000032:analysis; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D010974:Platelet Aggregation / Q000502:physiology; D012709:Serum Albumin / Q000032:analysis; D013499:Surface Properties; D013927:Thrombosis / Q000473:pathology*
D007074:Immunoglobulin G; D012709:Serum Albumin; D005340:Fibrinogen