**5. Conclusion**

Despite advances in hemodialysis-related technologies, there was no clear progress in terms of mortality benefit and clinical outcome. The ability to remove mediumhigh uremic toxins could provide a potential advantage. A number of dialyzers were developed over time, from low flow membranes to high flow dialyzers, the clearance of these molecules is still limited. The most recent and promising advance in the field of hemodialysis is represented by the development of medium-cutoff, high-retentiononset membranes. The combination of conventional hemodialysis and MCO membranes define expanded hemodialysis, this innovation in the field of dialysis allows diffusion and convection in a hollow fiber dialyzer. This gives it the capacity to purify

middle and large molecules without the need for large convective volumes and without a significant albumin loss. Its simple setup and application offer the possibility to use it even in patients with suboptimal vascular access or even with an indwelling catheter. Larger studies would be needed to further quantify any beneficial effects of HDx on major clinical events. Morbidity and mortality clinical studies are needed to demonstrate at least the non-inferiority of HDx over OL-HDF.
