Rethinking AVF Surveillance: Why Routine Monitoring Is No Longer Standard Practice
- Andrew Kowalski
- 5 days ago
- 5 min read
Andrew Kowalski, MD, FASN
Introduction
Arteriovenous fistulas (AVFs) remain the gold standard for hemodialysis vascular access due to their longevity, low infection risk, and superior patient outcomes compared to catheters and grafts. Historically, AVF surveillance used to be the norm in an attempt to catch culprit lesions early and prevent thrombosis and stenosis, ultimately aiming to prolong fistula patency. However, evolving evidence and large-scale trials have shifted clinical guidelines, challenging the utility and safety of routine AVF surveillance.
Photo from the University of Wisconsin School of Medicine
Despite having this evidence available, routine surveillance is still being conducted on our patients! I would hope that this is due to poor education and not keeping up to date with current guidelines and norms, but inappropriate use of routine surveillance is another bill that can be submitted helping the medical staff, but exposing the patient to harms. As a nephrologist and a interventionalist, I have come to understand, sympathize and appreciate a patient’s vascular access as being a true “life line.”
This blog explores the reasons behind this paradigm shift and outlines the potential harm associated with overzealous monitoring.
Historical Rationale for Surveillance
AVF surveillance developed from the assumption that early identification of a lesion or stenosis would allow for preemptive intervention, typically via angioplasty, before thrombosis or access failure occurred. In theory this held a sound foundation as preservation was our goal. Common surveillance methods included access flow measurement (e.g., ultrasound evaluation), static venous pressure monitoring, duplex ultrasound evaluation, and physical examination (bruits, thrill, pulse augmentation).
The logic seemed sound; detect trouble before it becomes a crisis. However, this approach did not adequately account for the many unique biological properties of AVFs or the natural history of maturation and adaptation, which differ significantly from synthetic grafts.
Evidence Challenging Routine Surveillance
Several randomized controlled trials and meta-analyses have questioned the benefit of routine surveillance in AVFs:
1. Randomized Clinical Trials
Hogg et al., 2013 (Canadian Trial): Found no significant difference in thrombosis rates or secondary patency between patients undergoing routine surveillance vs. those monitored only clinically.
Dember et al., 2004 (DAC Study): While focused more broadly on vascular access outcomes, this study highlighted the high rate of interventions without clear improvements in long-term access function.
Cochrane Reviews (latest in 2020): Concluded that routine surveillance may lead to more procedures without clear benefit in preventing thrombosis or prolonging AVF survival.
To summarize, these selected studies found that patients were exposed to a significantly higher rate of procedures (including spent time and larger insurance payouts) with no significant difference in outcomes. Meaning that regardless of how many “checks” are done the rate of issues, clotting or access failure did not change.
To use another analogy, repeatedly looking at a tire does not prevent it from getting a flat at some point.
2. Clinical Guidelines
KDOQI 2019 Update: No longer recommends routine AVF surveillance in asymptomatic patients. Instead, clinical monitoring (inspection, palpation, auscultation) and targeted diagnostics are favored.
European Renal Best Practice Guidelines: Emphasize individualized care rather than protocol-driven surveillance.
Key guidelines, that are now 6 years old at the time of writing this blog have already clearly stated not to perform surveillance. Yet patients are still being told by certain providers that this is necessary.
Why Routine Surveillance Can Be Harmful
The pivot away from routine surveillance is not just due to lack of benefit, it’s also because harm can result. Image frequently sticking an access, running a wire/catheter/balloon or even ultrasound probe throughout the vessel every 3 months or more. The interior of our vessels are not injury proof, there is fragile tissue and when aggravated or damaged can lead to an inflammatory response and scar tissue deposition.
Other harms that have been described in the literature include:
1. Overdiagnosis and Overtreatment
Identifying subclinical or hemodynamically insignificant stenoses can prompt unnecessary interventions. Every intervention causes micro tears that will lead to worsening issues in the future. Interventions should only be done when needed and not “just because.”
Balloon angioplasty or stent placement in a stable, functional fistula may disrupt natural remodeling. This I have seen many times. Unnecessary interventions and stent placement at one point in time seems harmless, but in 2-3 years when the fistula mature more, this stent is now an area of narrowing that will most certainly cause frequent problems and cannot be removed. Now the patient is dependent on frequent procedures to keep the access functioning as long as it can.
2. Iatrogenic Injury (injury caused by medical personnel)
Repeated angioplasty always causes endothelial damage, which leads to inflammation and scarring, ultimately accelerating the very stenosis it’s meant to treat. This is probably the most common preventable complication that is seen in our offices.
Fistula rupture, hematoma, and pseudoaneurysm formation can occur, particularly in immature or marginal fistulas. These injuries can happen, but frequent tinkering with the fistula and a sprinkle of machismo can almost guarantee a fistula ending injury. Time for another surgery to create another access.
3. Fistula Exhaustion
Each intervention carries the risk of access failure, and frequent interventions can and have ended in abandoning the access and the need to create a new one.
Treating “problems” that may never have become clinically relevant can shorten the lifespan of the access site.
4. Resource Utilization and Cost
High procedural burden on interventional nephrology/radiology or surgery services.
Increased healthcare costs with no corresponding improvement in patient outcomes. Cutting out unnecessary procedures can bring down the cost of healthcare; one goal we can all agree on.
5. Patient Burden
Repeated hospital visits, anxiety, post procedure pain, and recovery time impact patient quality of life.
Perceived dependence on a fragile access site can cause unnecessary psychosocial distress.
Shifting the Focus: Clinical Monitoring and Judicious Use of Imaging
The new standard emphasizes clinical monitoring, the art of listening to the thrill, assessing for changes in bruit, pulse, and cannulation quality, and reserving imaging for when problems are suspected. This individualized approach reduces harm and improves the patient experience without compromising access longevity.
Key principles include:
Educating and empowering dialysis staff to perform physical exams at each session.
Training clinicians to perform proper access physical exams and recognize signs of stenosis or dysfunction (e.g., prolonged bleeding, high venous pressures, low Kt/V).
Using diagnostic tools selectively when there’s clinical suspicion, not as routine. If there is suspicion, using noninvasive techniques, like ultrasound, can help diagnose a potential problem.
Conclusion
The era of routine AVF surveillance has ended years ago, replaced by a more patient-centered, evidence-based approach. While the intentions behind surveillance were noble, the reality is that routine monitoring often leads to unnecessary interventions, complications, and shortened AVF life. Patients need to be informed and educated to also become self advocates for their access. Clinical vigilance, rooted in skilled hands and attentive observation, remains the cornerstone of fistula management. In embracing this shift, nephrology moves toward a safer, more effective paradigm in vascular access care.
As clinicians our role is to first “Do no Harm,” not “Bill at the highest level.”