How can dialyzer designs improve solute clearances for hemodialysis patients?

Improvements in dialyzer technology and design have led to a reduction in both dialyzer size and cost, but also dialysis session treatment times as hemodialysis has evolved from using the cellulosic coiled drum dialyzer to the flat plate Kiil, to the current generation of hollow fiber capillary dialyzers. Newer manufacturing techniques have led to smoother, more consistent pore sizes and larger pore sizes increasing middle molecule clearances with the development of higher permeability dialyzers, and changing polymer composition to increase hydraulic permeability. Modifications to the dialyzer casing and capillary fibers can also increase the efficiency of solute clearances. Although very efficient in removing the smaller water-soluble azotemic toxins, the current generation of dialyzers is not so effective in removing other azotemic toxins, including protein-bound solutes, necessitating the development of newer designs.