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Updated: Sep 25, 2026
A Murine Model of Hemodialysis Access-Related Hand Dysfunction
Published on: May 31, 2022
A randomized controlled trial of blood flow and stenosis surveillance of hemodialysis grafts
Sunanda J Ram1, Jack Work, Gloria C Caldito
1Interventional Nephrology Section, Division of Nephrology and Hypertension, Department of Medicine, Louisiana State University Health Sciences Center, Shreveport, Louisiana, USA.
Insights
Hemodialysis graft surveillance using flow (Qa) or stenosis measurements did not improve graft survival. While stenosis surveillance reduced thrombosis, it did not significantly enhance long-term outcomes compared to clinical monitoring alone.
Area of Science:
- Nephrology
- Vascular Surgery
- Radiology
Background:
- Graft surveillance and stenosis correction are believed to reduce thrombosis and prolong hemodialysis graft survival.
- However, robust evidence from randomized controlled trials (RCTs) evaluating this approach is limited.
Purpose of the Study:
- To evaluate the effectiveness of hemodialysis graft surveillance strategies, specifically flow (Qa) and stenosis monitoring, on graft survival and thrombosis rates.
- To compare preemptive percutaneous transluminal angioplasty (PTA) rates and graft survival across different surveillance protocols.
Main Methods:
- A randomized controlled trial involving 101 patients assigned to control, flow (Qa), or stenosis surveillance groups.
- Monthly Qa and quarterly stenosis measurements were performed; angiography and preemptive PTA were triggered by specific criteria.
- Follow-up extended up to 28 months to assess graft outcomes.
Main Results:
- The preemptive PTA rate was highest in the stenosis group (0.65/patient year) compared to flow (0.34/patient year) and control (0.22/patient year) groups (P < 0.01).
- Graft thrombosis rates were similar in control (47%) and flow (53%) groups, but reduced in the stenosis group (29%, P = 0.10).
- Two-year graft survival rates were comparable across all groups: control (62%), flow (60%), and stenosis (64%) (P = 0.89).
Conclusions:
- Hemodialysis graft surveillance using Qa or stenosis measurements did not demonstrate improved graft survival.
- Although stenosis surveillance reduced thrombosis, it did not translate to superior long-term graft survival compared to aggressive clinical monitoring.
- The study suggests that monthly Qa and quarterly stenosis measurements may not be timely or accurate indicators for preventing thrombosis or progressive stenosis.
Background:
It is widely accepted that hemodialysis graft surveillance combined with correction of stenosis reduces thrombosis and prolongs graft survival. Nevertheless, few randomized controlled trials have evaluated this approach.
Methods:
In this randomized controlled trial, 101 patients were assigned to control, flow (Qa), or stenosis groups, and were followed for up to 28 months. All patients had monthly Qa measured by ultrasound dilution and quarterly percent stenosis measured by duplex ultrasound. Referral for angiography was based on the following criteria: (1) control group (N = 34), clinical criteria; (2) flow group (N = 32), Qa <600 mL/min or clinical criteria; and (3) stenosis group (N = 35), stenosis>50% or clinical criteria. Stenosis >or=50% during angiography was corrected by preemptive percutaneous transluminal angioplasty (PTA).
Results:
The preemptive PTA rate in the control group (0.22/patient year) was two thirds the rate in the flow group (0.34/patient year), and was highest in the stenosis group (0.65/patient year, P < 0.01). The percentage of grafts that thrombosed was similar in the control (47%) and flow groups (53%), but reduced in the stenosis group (29%, P = 0.10). Two-year graft survival was similar in the control (62%), flow (60%), and stenosis groups (64%) (P = 0.89).
Conclusion:
Qa and stenosis surveillance were not associated with improved graft survival, although thrombosis was reduced in the stenosis group. The most important factors in this result may be that monthly Qa and quarterly stenosis measurements were not accurate or timely indicators of risk of thrombosis or progressive stenosis. This study does not support the concept that Qa or stenosis surveillance are superior to aggressive clinical monitoring.
