Flow Dysfunction of Hemodialysis Vascular Access

Hemodialysis Access Failure Clinical Trial

— FLOW  

Official title:

Flow Dysfunction of Hemodialysis Vascular Access: a Randomized Controlled Trial on the Effectiveness of Surveillance of Arteriovenous Fistulas and Grafts

Clinical Trial Details — Status: Recruiting

Administrative data

• NCT number: NCT05906550
• Other study ID #: NL75845.068.20
• Secondary ID: NL9165
• Status: Recruiting
• Phase: N/A
• Start date: November 1, 2021
• Est. completion date: September 30, 2025

Study information

• Verified date: June 2023
• Source: Maastricht University Medical Center
• Contact: Maarten G Snoeijs, MD PhD
• Phone: 0031625097694
• Email: maarten.snoeijs[@]mumc.nl
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial 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.

Description:

Study design: Multicenter randomized controlled trial with 417 patients. Patients will be followed up for 2 to 3 years. The trial is powered to detect a reduction in the intervention rate of 0.25 per year between study groups in a superiority analysis (this is associated with cost savings of 1 million euros per year in the Netherlands). Subgroup analyses of arteriovenous fistulas and grafts and of successful and failed interventions will be done.

Study population: Chronic hemodialysis patients with a functioning arteriovenous fistula or graft.

Intervention group: 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.

Control group: 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.

Recruitment information / eligibility

• Status: Recruiting
• Enrollment: 417
• Est. completion date: September 30, 2025
• Est. primary completion date: September 30, 2025
• Accepts healthy volunteers: No
• Gender: All
• Age group: 18 Years and older

Eligibility

Inclusion Criteria:

1. Adult patients aged 18 years or older.

2. End-stage renal disease with unlikely recovery of kidney function according to the attending nephrologist.

3. Arteriovenous fistula or arteriovenous graft as hemodialysis vascular access that fulfills both of the following criteria at the time of trial enrollment:

1. Vascular access flow volume of at least 500mL/min; and

2. 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.

4. Planning to remain in one of the participating dialysis centers for at least 1 year.

Exclusion Criteria:

1. 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).

2. Home hemodialysis.

3. Thrombosis of the current vascular access in the past year.

4. Planned access-related intervention.

5. Living donor kidney transplantation, switch to peritoneal dialysis, or switch to home hemodialysis planned within 6 months.

6. Life expectancy of less than 6 months, in the opinion of the attending nephrologist.

7. Unable to provide informed consent.

Related Conditions & MeSH terms

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

Intervention

Diagnostic Test:
• Vascular access monitoring
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.
• Vascular access blood flow measurement
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.

Locations

Country	Name	City	State
Netherlands	Diapriva - Dialyse Centrum Amsterdam	Amsterdam
Netherlands	OLVG	Amsterdam
Netherlands	Deventer Ziekenhuis	Deventer
Netherlands	Medisch Spectrum Twente	Enschede
Netherlands	Spaarne Gasthuis	Haarlem
Netherlands	Zuyderland Medisch Centrum	Heerlen
Netherlands	Leids Universitair Medisch Centrum	Leiden
Netherlands	Maastricht UMC+	Maastricht
Netherlands	Bravis Ziekenhuis	Roosendaal
Netherlands	Franciscus Gasthuis & Vlietland	Rotterdam
Netherlands	Universitair Medisch Centrum Utrecht	Utrecht
Netherlands	Maxima Medisch Centrum	Veldhoven
Netherlands	Isala Klinieken	Zwolle

Sponsors (2)

Lead Sponsor	Collaborator
Maastricht University Medical Center	ZonMw: The Netherlands Organisation for Health Research and Development

Country where clinical trial is conducted

Netherlands, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	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	Access-related complications per patient-year (1)	Clavien-Dindo grade 2 complications (requiring pharmacological treatment)	Variable follow-up time of 2-3 years
Secondary	Access-related complications per patient-year (2)	Access-related serious adverse events (Clavien-Dindo grade 4 and 5 complications, and vascular access thrombosis)	Variable follow-up time of 2-3 years
Secondary	All-cause mortality	All-cause mortality	Variable follow-up time of 2-3 years
Secondary	Access-related health care costs (1)	Medical Consumption Questionnaire	Every 3 months for 2-3 years from randomization (variable follow-up time)
Secondary	Access-related health care costs (2)	Productivity Cost Questionnaire	Every 3 months for 2-3 years from randomization (variable follow-up time)
Secondary	Patient-reported outcome measures (1)	SF-VAQ (Short-Form Vascular Access Questionnaire)	Every 3 months for 2-3 years from randomization (variable follow-up time)
Secondary	Patient-reported outcome measures (2)	EQ-5D-5L	Every 3 months for 2-3 years from randomization (variable follow-up time)
Secondary	Quality of the surveillance program (1)	Repeatability and reproducibility of vascular access flow volume measurements	Variable follow-up time of 2-3 years
Secondary	Quality of the surveillance program (2)	Diagnostic accuracy of vascular access flow volume measurements to predict clinical signs of flow dysfunction and access thrombosis within 1 month in the intervention group	Variable follow-up time of 2-3 years
Secondary	Quality of the surveillance program (3)	The percentage of vascular access balloon angioplasties resulting in technical success (residual stenosis <30%) and clinical success (increase in flow volume to >500mL/min, restoration of vascular access function and resolution of any clinical signs of flow dysfunction)	Variable follow-up time of 2-3 years
Secondary	Quality of the surveillance program (4)	Vascular access patency after balloon angioplasty	Variable follow-up time of 2-3 years
Secondary	Primary patency	This outcome measure will be registered for explanatory analyses	Variable follow-up time of 2-3 years
Secondary	Assisted primary patency	This outcome measure will be registered for explanatory analyses	Variable follow-up time of 2-3 years
Secondary	Secondary patency	This outcome measure will be registered for explanatory analyses	Variable follow-up time of 2-3 years
Secondary	The number of hemodialysis sessions with cannulation difficulties	This outcome measure will be registered for explanatory analyses	Variable follow-up time of 2-3 years