Expanded Hemodialysis Versus High-Volume Online Hemodiafiltration for Uremic Toxin Removal

Summary

People with advanced kidney disease need dialysis to remove waste products from the blood. Some of these waste products, called uremic toxins, are small, while others are medium-sized and more difficult to remove. Poor removal of these toxins may contribute to symptoms and long-term complications in patients on dialysis.

Two dialysis techniques are commonly used to improve toxin removal beyond standard hemodialysis: expanded hemodialysis (HDx) using medium cut-off membranes, and high-volume online hemodiafiltration (HV-OL-HDF). Although both techniques are effective, the best way to prescribe expanded hemodialysis-particularly the ideal treatment time-has not been clearly defined.

The purpose of this study is to compare how well different treatment times of expanded hemodialysis remove small and medium-sized uremic toxins, and to compare these results with high-volume online hemodiafiltration. Toxin removal will be evaluated using a combined measurement called the Global Removal Score, which summarizes the removal of several important waste substances.

This is a single-center, randomized, open-label, crossover study. Adults receiving maintenance hemodialysis will receive three different expanded hemodialysis sessions with different treatment durations (180, 210, and 240 minutes), followed by one session of high-volume online hemodiafiltration. Blood samples will be taken before and after each dialysis session to measure toxin levels.

The results of this study may help determine whether expanded hemodialysis with shorter or standard treatment times can achieve toxin removal similar to high-volume hemodiafiltration, which could support more personalized and practical dialysis prescriptions.

Conditions

• End Stage Renal Disease (ESRD)
• Chronic Kidney Disease on Hemodialysis
• Renal Dialysis
• Uremia; Chronic
• Hemodialysis
• Hemodiafiltration

Interventions

DEVICE

Expanded Hemodialysis With Medium Cut-Off Membrane

Expanded hemodialysis will be performed using a medium cut-off dialysis membrane designed to enhance the removal of medium-sized uremic toxins while preserving albumin. Treatments will be delivered during regularly scheduled dialysis sessions with fixed dialysate flow and the maximum blood flow tolerated by the participant. Each participant will receive expanded hemodialysis sessions with three different treatment durations (180, 210, and 240 minutes), administered in randomized order following the long interdialytic interval. Blood samples will be collected before and after each session to assess removal of small and medium-sized uremic toxins.

DEVICE

High-Volume Online Hemodiafiltration

High-volume online hemodiafiltration will be delivered using post-dilution substitution during a standard dialysis session. Treatment will target a predefined convective volume consistent with high-volume hemodiafiltration while maintaining standard dialysis safety parameters. This intervention will be administered once to each participant after completion of the expanded hemodialysis sessions. Blood samples will be collected before and after the session to measure removal of small and medium-sized uremic toxins for comparison with expanded hemodialysis.

Sponsors & Collaborators

• Instituto Nacional de Ciencias Medicas y Nutricion Salvador Zubiran

  lead OTHER

Principal Investigators

• Olynka Vega, MS · Instituto Nacional de Ciencias Medicas y Nutrición Salvador Zubirán

Study Design

Allocation

NA

Purpose

TREATMENT

Masking

NONE

Model

SINGLE_GROUP

Eligibility

Min Age

18 Years

Sex

ALL

Healthy Volunteers

No

Timeline & Regulatory

Start

2026-04-30

Primary Completion

2026-04-30

Completion

2029-12-31

Countries

• Mexico

Study Locations