Anti-Clogging Effect of Continuous Hemodiafiltration With Blood Recirculation

Pediatric dialysis requires low flow from the body, but greater flow is needed to prevent clogging. As a solution, we developed a new continuous hemodiafiltration system with blood recirculation (CHDF-R), which enables separate settings for blood flow from the body and to the hemofilter. We compared CHDF-R with conventional continuous hemodiafiltration (CHDF) of bovine plasma and blood by monitoring the transmembrane pressure (TMP) and observing the hemofilter membrane surface. When using bovine plasma, the postdialysis TMP with CHDF-R was significantly lower than with CHDF (median CHDF, 23.7; median CHDF-R, 18.1; p = 0.029). Likewise, when using bovine blood, the postdialysis TMP was also significantly lower with CHDF-R than with CHDF (median CHDF, 150; median CHDF-R, 100; p = 0.029). Moreover, the area of clogged membrane was significantly smaller with CHDF-R than with CHDF, and the inner membrane surface showed less material deposition with CHDF-R than CHDF. CHDF-R thus appears to suppress accumulation of clogging substances by producing higher shear stress within hollow fiber membranes.