[Compared study of micro-aggregates filters (output, filtration pressure and study of the deposit with scanning...

Special filters for the elimination of cellular aggregates were conceived especially to prevent pulmonary complications in patients shocked particularly after massive transfusions as well as to prevent cerebral complications after extra-corporeal circulation. The performances and the conditions of use of these filters (perfusion output, change of the filter) were considered. Four filters were carefully studied: the Fenwal filter, the Swank filter, the Biotest filter and the intersep Johnson and Johnson filter. The following studies were carried out for each filter: the perfusion output (of three bottles filtered one after another with or without pressure); the filtration pressure (Swank technique) of the whole blood up-and-down filter; the viscosity and various hematologic parameters (NF, hemoglobin and gobular ATP); finally, the deposit was studied morphologically with scanning electron microscopy. It appeared that a good capacity of aggregates elimination (decrease of the filtration pressure of 95%) was often linked to a feeble output and the necessity of replacing the filter. The efficacy of the Fenwal filter, the Swank filter, the Biotest filter and the intersept filter was practically the same, but the Intersept filter provided the best output with an equal filtration capacity. The other parameters remained about the same. The deposits included fibrinogen, deformed red blood corpuscules (echinocytes), leucocytes and platelets.