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Abstract: TH-PO752

Quantification of Internal Filtration in Hollow Fiber Hemodialyzers with Medium Cut-Off Membrane

Session Information

  • Bioengineering
    October 25, 2018 | Location: Exhibit Hall, San Diego Convention Center
    Abstract Time: 10:00 AM - 12:00 PM

Category: Bioengineering

  • 300 Bioengineering


  • Lorenzin, Anna, IRRIV, Vicenza, Italy
  • Neri, Mauro, IRRIV, Vicenza, Italy
  • Brendolan, Alessandra, St Bortolo Hospital, Vicenza, Italy
  • Ronco, Claudio, St Bortolo Hospital, Vicenza, Italy

Inadequate removal of molecules between 5 and 50KDa may cause long term complication in chronic hemodialysis. Medium Cut-off (MCO) is a new class of membranes with enhanced sieving properties and negligible albumin loss. MCO membrane allows to perform expanded hemodialysis (HDx), a technique based on high internal filtration (IF).The present study is designed to quantify IF in two MCO dialyzers (Theranova 400 and 500, Baxter, Deerfield, USA) using a nuclear imaging technique previously validated.


Blood and dialysate compartment pressure drop along with transmembrane pressure, were measured in a closed in vitro circuit with human blood (blood flow (QB)=300 and 400ml/min; dialysate flow 500ml/min; net ultrafiltration rate 0ml/min). A non-diffusible marker molecule (albumin macro-aggregates labelled with 99Tc metastable) was injected in the blood compartment and nuclear emission was recorded by a gamma camera. Relative variations in concentration of the marker molecule along the length of the filter were used to calculate local cross filtration.


Based on marker concentration profiles, IF was estimated (Figure 1). For Theranova 400, IF were 29.7 and 41.6ml/min for QB of 300 and 400ml/min. For Theranova 500, IF were 31.6 and 53.1ml/min for QB of 300 and 400ml/min respectively.


MCO membrane provides significant amounts of IF due to the particular combination between hydraulic permeability of the membrane and reduced inner diameter of the fibers. High IF combined with enhanced sieving profile of MCO membrane, leads to improved removal of a wider spectrum of uremia retention molecules in HDx, without requiring complex equipment.

Scintigraphic images at steady state and marker molecule count profiles for Theranova 400 and Theranova 500.