Interventional Radiology Imaging

How Should You Work Up a Thrombosed Dialysis Access with Absent Pulse and Thrill?

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How Should You Work Up a Thrombosed Dialysis Access with Absent Pulse and Thrill?

A patient with end-stage renal disease arrives for their scheduled hemodialysis session. The dialysis nurse performs the routine pre-cannulation physical exam on the patient’s arteriovenous fistula and finds a problem: there is no palpable thrill and no audible bruit. The access feels firm and has no pulse. This is a clinical emergency for the patient, who cannot receive life-sustaining dialysis without a functioning access. The nephrologist is called, and the immediate question is not just what is wrong, but what is the fastest, most effective way to restore flow. This article provides a step-by-step clinical workflow for this exact scenario, anchored in the American College of Radiology (ACR) Appropriateness Criteria. For a patient with suspected access thrombosis marked by an absent pulse and thrill, the ACR rates Fluoroscopy fistulography hemodialysis access with intervention as Usually Appropriate.

Who Fits This Clinical Scenario for a Thrombosed Dialysis Access?

This guidance is specifically for patients with an established upper or lower extremity hemodialysis access—either an arteriovenous fistula (AVF) or an arteriovenous graft (AVG)—who present with the acute and definitive signs of thrombosis. The key inclusion criteria are the physical examination findings of a completely absent pulse and absent thrill over the body of the access. These signs strongly suggest a lack of blood flow and occlusion of the circuit.

It is critical to distinguish this scenario from other forms of dialysis access dysfunction, which follow different diagnostic pathways:

  • Exclusion 1: Weak but Present Thrill: If the patient has a diminished or weak pulse/thrill but flow is still present, the situation is less acute. This presentation fits the “Suspected dysfunction” variant, where diagnostic imaging may precede intervention.
  • Exclusion 2: Abnormal Dialysis Parameters: If the physical exam is normal but dialysis parameters (e.g., high venous pressures, prolonged bleeding, low urea reduction ratio) suggest a problem, this also falls under the “Suspected dysfunction” category, typically indicating a stenosis that has not yet led to thrombosis.
  • Exclusion 3: Failure to Mature: This workflow does not apply to a newly created fistula that has never developed adequate flow for cannulation. That scenario has its own dedicated ACR criteria for both initial imaging and subsequent treatment.
  • Exclusion 4: Isolated Extremity Swelling: If the primary sign is arm, neck, or facial swelling with a patent fistula, the workup should focus on suspected central venous stenosis.

This article is for the thrombosed, non-functional access that requires urgent restoration.

What Diagnoses Are You Working Up with a Pulseless Dialysis Access?

When a dialysis access suddenly loses its pulse and thrill, you are working up a time-sensitive occlusion. The differential diagnosis is narrow, but identifying the underlying cause is crucial for successful intervention and long-term patency.

The most common and immediate diagnosis is acute access thrombosis. This is the event that causes the clinical presentation. Blood flow has ceased, and clot has formed within the fistula or graft. This is often precipitated by an underlying anatomical problem, systemic issue like hypotension during a prior dialysis session, or a period of hypercoagulability. The primary goal of intervention is to remove this thrombus.

However, thrombosis is rarely a spontaneous event. The most frequent underlying cause is a high-grade stenosis somewhere in the access circuit. This flow-limiting lesion creates turbulence and low flow, predisposing the access to thrombosis. The most common locations are the venous anastomosis (for a graft) or juxta-anastomotic region (for a fistula), but stenoses can occur anywhere along the outflow vein, all the way to the central veins. The interventional procedure must identify and treat this culprit lesion to prevent rapid re-thrombosis.

A less common but critical consideration is a severe arterial inflow stenosis. If the artery feeding the fistula is severely diseased, it may not provide enough blood flow to keep the access open. While this is a less frequent cause of acute thrombosis than venous outflow stenosis, failing to recognize and address it will lead to procedural failure.

Finally, central venous stenosis or occlusion can be a contributing factor. If the subclavian vein, brachiocephalic vein, or superior vena cava is severely narrowed, it creates significant back-pressure on the entire access circuit, leading to poor flow and eventual thrombosis. While often associated with arm swelling, it can also present as acute access failure.

Why Is Fluoroscopic Fistulography with Intervention Usually Appropriate Here?

For a thrombosed dialysis access, the clinical need is not just for diagnosis but for immediate treatment. This is why the ACR designates Fluoroscopy fistulography hemodialysis access with intervention as Usually Appropriate. This single procedure combines definitive diagnosis with therapeutic action, making it the most efficient and effective approach. It directly addresses the differential by allowing the interventional radiologist or vascular surgeon to visualize the entire circuit, from the arterial inflow to the central veins, identify the thrombus and the underlying stenosis, and treat both in the same session.

In contrast, other options are rated lower for this specific, urgent scenario:

  • US Duplex Doppler hemodialysis access area of interest is rated Usually Not Appropriate. While ultrasound is excellent for evaluating a dysfunctional but patent access, its role in a thrombosed access is limited. It can confirm the absence of flow and may identify the location of the thrombus, but it provides no therapeutic benefit. The patient would still require a separate interventional procedure, causing unnecessary delay. The primary goal is to restore access, not simply to confirm its occlusion with a non-therapeutic test.
  • Surgical consultation is also rated Usually Appropriate. This is considered an equivalent first-line option. The choice between endovascular (fistulography with intervention) and open surgical thrombectomy often depends on local expertise, operator preference, and specific patient factors. Both aim to restore patency.
  • Placement of a new tunneled dialysis catheter is rated May be appropriate. This is not a treatment for the thrombosed fistula but rather a temporizing measure to provide immediate dialysis access. It is often necessary if the thrombectomy procedure is unsuccessful, delayed, or if the patient is not a candidate for salvage. It can also be placed at the beginning of the salvage procedure to ensure dialysis can be performed immediately after.

The recommended fluoroscopic procedure is both a roadmap and a toolkit. It is the standard of care because it minimizes delay to treatment, provides a comprehensive anatomical assessment, and offers a high likelihood of successfully salvaging the patient’s vital dialysis access.

What’s Next After Fluoroscopic Fistulography with Intervention? Downstream Workflow

The outcome of the fistulography and intervention dictates the immediate next steps for the patient’s dialysis care. The post-procedure workflow is a clear decision tree based on the findings and technical success.

  • If the procedure is successful: If the thrombus is removed (thrombectomy) and the underlying stenoses are treated (angioplasty and/or stenting), a strong thrill and pulse should be restored to the access. The patient can typically use the salvaged fistula or graft for their next scheduled dialysis session, often the same day. The interventionalist’s report will detail any residual stenosis and recommend a surveillance schedule, usually involving follow-up physical exams and potentially a duplex ultrasound in the coming weeks to monitor for recurrent narrowing.
  • If the procedure is technically unsuccessful: If the clot cannot be cleared or a critical stenosis cannot be crossed or dilated, the access is considered unsalvageable. At this point, the immediate priority is to secure a different means for dialysis. This typically involves placing a tunneled central venous catheter, a procedure rated May be appropriate in the initial ACR criteria. The patient will use this catheter for dialysis while plans are made for creating a new permanent access at a different site.
  • If the procedure is partially successful or reveals complex anatomy: Sometimes, flow can be restored, but significant underlying issues remain, such as severe central venous stenosis or poor arterial inflow. The patient may be able to use the access temporarily, but a multidisciplinary discussion between nephrology, interventional radiology, and vascular surgery is crucial. Further interventions may be planned, or the team may decide to use the access for a short period while a new, more durable access is created and matures.

Pitfalls to Avoid (and When to Get Help)

Navigating a thrombosed dialysis access requires timely and correct action. Here are common pitfalls to avoid in this specific scenario:

  • Delaying the procedure: A thrombosed access is a clinical urgency. The longer the clot sits, the more organized it becomes, and the more difficult it is to remove. Prompt consultation with interventional radiology or vascular surgery is key to maximizing the chance of successful salvage.
  • Ordering a diagnostic-only study: As noted, ordering a duplex ultrasound as the first step is Usually Not Appropriate. It confirms what the physical exam already strongly suggests and delays the necessary therapeutic intervention.
  • Ignoring the central veins: A successful thrombectomy and angioplasty of the peripheral access can still fail if a significant, untreated central venous stenosis is present. A complete fistulogram must always include visualization of the central veins.
  • Failing to plan for alternative access: Even with high success rates, not all thrombosed accesses can be salvaged. It is prudent to have a concurrent or backup plan for placing a tunneled dialysis catheter so the patient does not miss their required dialysis treatments.

If the initial endovascular attempt is unsuccessful or if complex central venous or arterial inflow disease is discovered, immediate escalation and discussion with a vascular surgeon is the appropriate next step.

Related ACR Topics and Tools

For a comprehensive overview of all clinical variants related to dialysis access imaging, please refer to our parent topic guide. Additionally, several GigHz tools can support your clinical decision-making for this and adjacent scenarios.

Frequently Asked Questions

Why is an absent thrill and pulse considered an urgent issue for a dialysis access?

An absent thrill and pulse are the classic physical exam signs of access thrombosis, meaning the fistula or graft is occluded by a blood clot. Without a functioning access, the patient cannot undergo hemodialysis, which is a life-sustaining treatment. Prompt intervention is required to restore blood flow and salvage the access.

Is there a role for anticoagulation before the fistulography procedure?

Systemic anticoagulation is generally not initiated in the outpatient or emergency setting for a thrombosed access prior to intervention. The definitive treatment is mechanical or pharmacomechanical thrombectomy to physically remove the clot. Anticoagulation protocols are typically managed by the interventionalist during and immediately after the procedure itself.

What is the difference between a fistulogram and a thrombectomy?

A fistulogram (or fistulography) is the diagnostic part of the procedure where contrast dye is injected to create an X-ray map of the entire access circuit. This identifies the location of the clot and any underlying stenoses. A thrombectomy is the therapeutic part, where specialized devices are used to break up and remove the clot. They are performed together in the same session for a thrombosed access.

If the access is a graft (AVG) instead of a fistula (AVF), does this workflow change?

No, the clinical workflow recommended by the ACR is the same for both thrombosed arteriovenous grafts and fistulas. The primary recommendation remains fluoroscopic fistulography with intervention. While the technical aspects of the procedure and long-term patency rates may differ between grafts and fistulas, the initial management for acute thrombosis is identical.

Can a thrombosed access be used for dialysis immediately after a successful intervention?

Yes, in most cases. A key advantage of successful endovascular salvage is that the access can often be used for dialysis on the same day. The interventionalist will confirm that flow is restored and will communicate with the nephrology and dialysis teams regarding the readiness of the access for cannulation.

Reviewed by Pouyan Golshani, MD, Interventional Radiologist — May 30, 2026