Flow Dysfunction of Hemodialysis Vascular Access

NCT05906550 | Completed DMC

• 2 other identifiers: NL75845.068.20NL9165
• Study Type: interventional
• Target: 375
• Locations: 1 country
• Sites: 13

Brief Summary

The FLOW trial evaluates the follow-up of the vascular access for hemodialysis. In current clinical care, vascular access flow volume is periodically assessed to detect and treat asymptomatic stenosis. The FLOW trial will determine whether it is safe to abandon this practice of active surveillance. Vascular access stenosis will then be treated only when clinical problems of flow dysfunction occur during hemodialysis. The investigators expect that the intervention rate and medical costs will be reduced by 40% when correction of vascular access stenosis is triggered by clinically apparent access dysfunction rather than asymptomatic flow reduction.

Conditions

Dialysis Access Malfunction; Hemodialysis Access Failure; Hemodialysis Fistula Thrombosis; Vascular Access Malfunction

Outcome Measures

Primary Outcomes (1)

• Access-related intervention rate

  The number of interventions required for each patient-year of hemodialysis treatment

  Variable follow-up time of 2-3 years

Secondary Outcomes (15)

• Access-related complications per patient-year (1)

  Variable follow-up time of 2-3 years

• Access-related complications per patient-year (2)

  Variable follow-up time of 2-3 years

• All-cause mortality

  Variable follow-up time of 2-3 years

• Access-related health care costs (1)

  Every 3 months for 2-3 years from randomization (variable follow-up time)

• Access-related health care costs (2)

  Every 3 months for 2-3 years from randomization (variable follow-up time)

Study Arms (2)

Intervention group

EXPERIMENTAL

Patients are referred for correction of the underlying stenosis when clinical signs of flow dysfunction are present. These include physical signs, problems during dialysis, or an unexplained, sustained fall in dialysis adequacy.

Diagnostic Test: Vascular access monitoring

Control group

ACTIVE COMPARATOR

Monthly surveillance of vascular access blood flow volume by ultrasound dilution measurements during hemodialysis sessions. Patients will be referred for correction of the underlying stenosis at an access flow volume \<500mL/min, or when clinical signs of flow dysfunction are present.

Diagnostic Test: Vascular access monitoring; Diagnostic Test: Vascular access blood flow measurement

Interventions

Vascular access monitoring DIAGNOSTIC_TEST

Patients are referred for correction of the underlying stenosis when clinical signs of flow dysfunction are present. These include physical signs, problems during dialysis, or an unexplained, sustained fall in dialysis adequacy. Patients will be referred for correction of the underlying stenosis when clinical signs of flow dysfunction are present.

Control group; Intervention group

Vascular access blood flow measurement DIAGNOSTIC_TEST

Monthly surveillance of vascular access blood flow volume by ultrasound dilution measurements during hemodialysis sessions. Patients will be referred for correction of the underlying stenosis at an access flow volume \<500mL/min.

Control group

Eligibility Criteria

• Age: 18 Years+
• Sex: all
• Healthy Volunteers: No
• Age Groups: Adult (18-64), Older Adult (65+)

You may qualify if:

• Adult patients aged 18 years or older.
• End-stage renal disease with unlikely recovery of kidney function according to the attending nephrologist.
• Arteriovenous fistula or arteriovenous graft as hemodialysis vascular access that fulfills both of the following criteria at the time of trial enrollment:
• Vascular access flow volume of at least 500mL/min; and
• Functional vascular access: the vascular access was cannulated with 2 needles and achieved the prescribed access circuit flow in at least 6 dialysis sessions over the past 30 days. Patients who have single needle hemodialysis for reasons other than vascular access dysfunction (e.g. for nocturnal hemodialysis) but who can be cannulated with 2 needles for flow measurements and fulfill the other requirements for a functional vascular access can be enrolled as well.
• Planning to remain in one of the participating dialysis centers for at least 1 year.

You may not qualify if:

• Arteriovenous fistulas with multiple venous outflow paths upstream of the cannulation sites, that are not suitable for flow volume measurements using ultrasound dilution (e.g. Gracz fistulas and Ellipsys or WavelinQ endovascular fistulas).
• Home hemodialysis.
• Thrombosis of the current vascular access in the past year.
• Planned access-related intervention.
• Living donor kidney transplantation, switch to peritoneal dialysis, or switch to home hemodialysis planned within 6 months.
• Life expectancy of less than 6 months, in the opinion of the attending nephrologist.
• Unable to provide informed consent.

Sponsors & Collaborators

• Maastricht University Medical Center: lead
• ZonMw: The Netherlands Organisation for Health Research and Development: collaborator

Study Sites (13)

Diapriva - Dialyse Centrum Amsterdam

Amsterdam, Netherlands

Location

OLVG

Amsterdam, Netherlands

Location

Deventer Ziekenhuis

Deventer, Netherlands

Location

Medisch Spectrum Twente

Enschede, Netherlands

Location

Spaarne Gasthuis

Haarlem, Netherlands

Location

Zuyderland Medisch Centrum

Heerlen, Netherlands

Location

Leids Universitair Medisch Centrum

Leiden, Netherlands

Location

Maastricht UMC+

Maastricht, Netherlands

Location

Bravis Ziekenhuis

Roosendaal, Netherlands

Location

Franciscus Gasthuis & Vlietland

Rotterdam, Netherlands

Location

Universitair Medisch Centrum Utrecht

Utrecht, Netherlands

Location

Maxima Medisch Centrum

Veldhoven, Netherlands

Location

Isala Klinieken

Zwolle, Netherlands

Location

Study Officials

• Maarten G Snoeijs, MD PhD

  Maastricht University Medical Center

  PRINCIPAL INVESTIGATOR

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: QUADRUPLE
• Who Masked: PARTICIPANT, CARE PROVIDER, INVESTIGATOR, OUTCOMES ASSESSOR
• Masking Details: The software of the HD03 Hemodialysis Monitor will be adjusted to allow blinded measurements that will be sent to the trial coordinator; patients and health care providers remain unaware of treatment allocation and surveillance findings. Flow measurements will only be used to refer patients for correction of vascular access stenosis in the control group. To maintain blinding, whenever a measurement must be repeated to confirm low flow volumes, another trial participant will randomly be selected for confirmation of vascular access flow volumes after the next measurement. Patients will be censored and randomized anew following an intervention for flow dysfunction, as soon as the indicator for vascular access intervention has been resolved and vascular access function has been restored.
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: SPONSOR

Model Details: Double blind randomized controlled trial with hybrid parallel-crossover design

Study Record Dates

• First Submitted: May 23, 2023
• First Posted: June 18, 2023
• Study Start: November 1, 2021
• Primary Completion: December 31, 2025
• Study Completion: December 31, 2025
• Last Updated: February 5, 2026

Record last verified: 2026-02

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL, SAP, CSR, ANALYTIC CODE
• Time Frame: The embargo period will be as long as required for publication of the research findings.
• Access Criteria: Interested parties can submit a request for a data set.

Locations

NL (13)