Kidney Week

Abstract: TH-PO1283

Flow Surveillance or Clinical Monitoring to Guide Vascular Access Maintenance: A Double-Blind Randomized Controlled Trial

Session Information

• Late-Breaking Research Posters
  October 22, 2026 | Location: Exhibit Hall A, Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Dialysis

• 803 Dialysis: Vascular Access

Authors

• Zomer, Bianca, Maastricht Universitair Medisch Centrum+, Maastricht, LI, Netherlands

Bianca Zomer, MD

• Goertz, Ellen, Maastricht Universitair Medisch Centrum+, Maastricht, LI, Netherlands

Ellen Goertz

• de Haan, Michiel Willem, Maastricht Universitair Medisch Centrum+, Maastricht, LI, Netherlands

Michiel Willem de Haan, MD, PhD

• Hemmelder, Marc H., Erasmus MC, Rotterdam, ZH, Netherlands

Marc H. Hemmelder, MD, PhD

• Hiligsmann, Mickaël, Universiteit Maastricht, Maastricht, LI, Netherlands

Mickaël Hiligsmann, PhD

• Loon, Magda Van, Maastricht Universitair Medisch Centrum+, Maastricht, LI, Netherlands

Magda Van Loon, PhD, NP

• Rotmans, Joris I., Leids Universitair Medisch Centrum, Leiden, ZH, Netherlands

Joris I. Rotmans, MD, PhD

• Schurink, Geert Willem H., Maastricht Universitair Medisch Centrum+, Maastricht, LI, Netherlands

Geert Willem H. Schurink

• van der Vorst, Joost, Leids Universitair Medisch Centrum, Leiden, ZH, Netherlands

Joost van der Vorst, MD, PhD

• Snoeijs, Maarten G., Maastricht Universitair Medisch Centrum+, Maastricht, LI, Netherlands

Maarten G. Snoeijs, MD, PhD

Group or Team Name

• FLOW Study Group.

Background

Arteriovenous fistulas and grafts frequently develop stenosis, which may lead to flow dysfunction, thrombosis, and access abandonment. Flow measurements during hemodialysis can detect asymptomatic stenosis, but the clinical benefit of flow surveillance remains uncertain.

Methods

In this multicenter, double-blind, RCT, patients with a functional arteriovenous fistula or graft and access flow >500 mL/min were randomized to monthly flow surveillance or clinical monitoring only. Patients with vascular access thrombosis in the previous year were excluded. All patients underwent clinical assessment at every dialysis session and blinded monthly flow measurement. Interventions were performed for clinical indicators of flow dysfunction. In the surveillance group, the access team was notified when flow was <500 mL/min and intervention was planned. In the clinical monitoring group, flow measurements remained blinded. The primary endpoint was the rate of access-related interventions per patient-year. Safety endpoints were access-related serious adverse events (SAEs) and thrombosis. Study groups were compared using general linear mixed effect models with negative binomial distribution.

Results

Of 375 patients, 190 were allocated to clinical monitoring and 185 to flow surveillance. Mean age was 67 years, 92% had arteriovenous fistulas, and mean baseline flow was 1.2 L/min. Of 5,639 flow measurements, 325 (5.8%) were <500 mL/min, with 206 (3.6%) confirmed during subsequent dialysis sessions. The overall rate of access-related interventions was 0.40/year with clinical monitoring only and 0.54/year with flow surveillance (P=0.065); the rate of percutaneous interventions was 0.24/year and 0.43/year (P=0.004). Access-related SAEs, access thrombosis and access abandonment were not significantly different between the groups.

Conclusion

Monthly flow surveillance increased percutaneous interventions without reducing vascular access thrombosis. Clinical monitoring alone is sufficient to guide vascular access maintenance.

Results

Funding

• Government Support - Non-U.S.