In vitro evaluation of the Mera Silox-S 0.5 and 0.8 m2 silicone hollow-fibre membrane oxygenator for use in neonatal ECMO

Abstract

The Mera Silox-S is a silicone hollow-fibre membrane oxygenator made up of thousands of fibres in a clear polycarbonate housing. Being a silicone membrane it does not have the plasma leakage problem associated with conventional microporous hollow fibres when used in a long-term application. This device (Mera Senko Medical Instrument Co., Japan) is made in three sizes: 0.3, 0.5 and 0.8 m2. The performance of the 0.5 m2 and 0.8 m2 Silox-S membrane oxygenators was tested in vitro using filtered ovine blood and a customized test circuit designed to provide a continuous source of de-oxygenated, CO2-laden blood, according to the AAMI standard for oxygenator performance. The 0.8 m2 membrane provided excellent oxygenation, with a transfer rate of 13.0-43.5 ml/min for blood flows of 200-800 ml/min. CO2 transfer over the same range of flows measured 32.3-40.8 ml/min. Flow rates of 100-500 ml/min for the 0.5 m2 membrane provided an oxygen transfer of 6.8-28.3 ml/min and would probably not be suited for the existing neonatal ECMO population. A matter of concern with both oxygenators was an increased pressure drop for blood flow through the devices. The Δ Pfor the 0.5 m2 for flows of 100-500 ml/min ranged from 155 ± 7 mmHg to 516 ± 6 mmHg. For the 0.8 m2, Δ P was 194 ± 39 mmHg to 492 ± 53 mmHg for flows of 200-800 ml/min. Overall, favourable results support further long-term evaluation for potential use in neonatal ECMO.