Kidney Week

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

Authors

• Lorenzin, Anna, IRRIV, Vicenza, Italy

Anna Lorenzin,

• Neri, Mauro, IRRIV, Vicenza, Italy

Mauro Neri,

• Brendolan, Alessandra, St Bortolo Hospital, Vicenza, Italy

Alessandra Brendolan,

• Ronco, Claudio, St Bortolo Hospital, Vicenza, Italy

Claudio Ronco,

Background

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.

Methods

Blood and dialysate compartment pressure drop along with transmembrane pressure, were measured in a closed in vitro circuit with human blood (blood flow (Q_B)=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.

Results

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

Conclusion

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.