The Comparative Evaluation of Transfusion Microfilters

Abstract

Seven transfusion microfilters of different design for the removal of microaggegates from stored blood are now available commercially. This study was undertaken to compare the effectiveness of five microfilters-Pall filter (40μ grid, screen type), Terufusion filter (20μ, depth type), Swank filter (10μ, depth type), Bentley filter (27μ, depth type), and Johnson & Johnson filter (20μ, screen and depth type). Out dated A C D human whole blood was used to evaluate the ability of the filters for the elimination microaggregates. Samples of blood, before and after filtration, were analyzed for volume, size and distribution of microaggregates by Coulter counter model TA II (equipped with a 280μ Aperture).Results : (1) All filters were effective for the removal of microaggregates with the diameter of 40μ or more ; however, it still seemed questionable that the post filtrated blood would be free from microaggregates. (2) There were some differences in the effectiveness of the filters in removing particles less than 40μ in diameter. The Pall filter (40μ grid filter) was the least effective among them as might be expected. The Terufusion filter and Swank filter were more effective than others.