Removal of Particle Contamination in the Extracorporeal Circuit Detected by an In-Line Particle Counter

We investigated the number and size of the particles (diameter:> 1 μm) in the extracorporeal circuit by means of a particle counter. We also evaluated the efficacy of pre-bypass filters in the extracorporeal circuit. During in vitro tests, the removal efficiency of the Pall PP3802 and the Harvey H-600 were 99.3% and 63.8% respectively after recirculating for 5 minutes. In clinical cases, the mean number of particles in the cardiopulmonary circuit after a 5 minute recirculation was 4287 ± 836 particles/ml (pcs/ml). After using the PP3802, it dropped to 52 ± 11 pes/ml. It is desirable to use a .2 μm prebypass filter for recirculating all cardiopulmonary products before operation.