Vena Cava Ring Tests of Biomaterials in Dogs.

摘要

Canine vena cava implant tests for thrombogenicity were performed on materials submitted by various contractors in the NHLI biomaterials program. Among valid tests, 44% of the specimens produced little or no attached thrombus and no major thromboembolic complications after two weeks'implantation. Three groups of materials tested in meaningful quantity produced results distinctly better than the average. These included various heparinized surfaces (59% or 22of 37with little or no thrombus),perfluorinated ethylcellulose coatings (80% or 8of 10),and glow discharge polymerized tetramethyldisiloxane (73% or 8of 11). Accumulated test data were analyzed statistically to determine if variations in several test animal parameters correlated with rapidity and severity of thrombus formation. It was found that changes in red cell count and partial thromboplastin time over normally encountered ranges had small but significant effects.