NCT05906550

Flow Dysfunction of Hemodialysis Vascular Access

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

• Status: Completed
• Phase: N/A
• Study type: Interventional
• Enrollment: 375 (actual)
• Sponsor: Maastricht University Medical Center · Academic / Other
• Sex: All
• Age: 18 Years
• Healthy volunteers: Not accepted

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.

Detailed description

Study design: Multicenter randomized controlled trial with 375 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. On 25-02-2025, the sample size was reduced from 417 to 375 patients because updated calculations based on actual event and loss to follow-up rates in the trial population showed sufficient power to detect the prespecified clinically relevant difference. 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.

Conditions

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

Interventions

Type	Name	Description
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.
DIAGNOSTIC_TEST	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.

Timeline

• Start date: 2021-11-01
• Primary completion: 2025-12-31
• Completion: 2025-12-31
• First posted: 2023-06-18
• Last updated: 2026-02-05

Locations

13 sites across 1 country: Netherlands