Clinical Performance Assessment of CorDiax Filters in Hemodialysis and Hemodiafiltration

Abstract

In this study, we evaluate the in vivo clinical performances of CorDiax FX 100 and CorDiax FX 1000 filters incorporating a high-flux membrane (Helixone Plus) designed for use in high-flux hemodialysis (HD) as well as in hemodiafiltration (HDF) in 6 stable end-stage kidney disease patients. In the HDF mode, various substitution modalities (post-, pre-, and mixed) were compared. In addition to conventional markers of efficacy of dialysis dose (urea, ionic dialysance, Kt/V), several additional middle- and large-size solute (β2-microglobulin, myoglobin, serum-free light-chain kappa and lambda, α1-microglobulin, and FGF23) compounds were explored in order to cover the spectrum of uremic toxins that are involved in uremia. A precise quantitative assessment of solute removal was performed in this study mimicking solute kinetic complexity during patient/dialysis interaction (hemoconcentration due to volume contraction, postdialysis rebound due to compartmentalization effect) in order to fit better with clinical reality and to provide clinicians more realistic estimates of solute mass transfer. The study confirms that effective solute body clearances achieved in vivo both in HD and in HDF are significantly lower than instantaneous clearances reported by manufacturers. Among dialysis modalities assessed in this study, postdilution HDF offers the most efficient modality both in terms of solute removal capacity and substitution volume used. The predilution HDF mode provides slightly but significantly lower body clearances than the postdilution mode over the spectrum of solutes assessed, a dilution factor that can be compensated for by increasing the substitution rate adequately. The clinical performance of CorDiax FX filters featuring the same highly permeable membrane engineered in 2 different configurations, one facilitating internal convective transport in HD (high internal resistance) and the other favoring high-volume on-line HDF (low internal resistance), offers interesting and effective options for enhancing removal of middle- and larger-size uremic compounds. High-volume HDF relying on different fluid substitution modes remains the more efficient modality across a large spectrum of uremic compounds tested.