Deposition of blood elements on vacuum-formed ventricles in calves. A gross and electron microscopic study.
The thrombogenicity of the Philadelphia Heart System was evaluated by implanting left and right ventricles in calves for periods ranging from 1.5 hours to 128 days. Explanted hearts were examined grossly and by scanning and transmission electron microscopy for accumulation of thrombus and ingrowth of pseudoneointima. Visible material was essentially limited to inflow and outflow valves, atrial cuff, and a circumferential band of white thrombus around the junction of the blood diaphragm with the housing. The band was barely visible at 33 days, but was 1 to 3 mm wide at 128 days. SEM examination revealed microscopic deposits of blood elements, mostly platelets, that were present between 10 days and 128 days. The deposits were rather uniformly distributed over the blood contacting surface and remained constant over time. At 128 days, the Dacron (Meadox Medical, Oakland, NJ) graft was partly covered by a thin layer of tissue composed of multiple layers of cells separated by collagen. New blood vessels were frequently found, but fibrin-rich thrombus was present in some areas. Thus, this system was capable of minimizing thrombus accumulation and remained stable for 4 months.
DeFeo
P A
PA
Thrombosis Research Center, Temple University School of Medicine, Philadelphia, Pennsylvania 19140.
Wurzel
D
D
Wildevuur
W
W
Hansen
G
G
Kolff
J
J
Stewart
G J
GJ
D000818:Animals; D001773:Blood Cells / Q000648:ultrastructure*; D001792:Blood Platelets / Q000648:ultrastructure; D002417:Cattle; D003094:Collagen; D006354:Heart, Artificial / Q000009:adverse effects*; D008297:Male; D008854:Microscopy, Electron; D008855:Microscopy, Electron, Scanning; D013927:Thrombosis / Q000209:etiology* / Q000473:pathology; D013997:Time Factors
D003094:Collagen