Interventional Radiology Imaging

How Should You Manage Skin Changes Over a Hemodialysis Access Site? An ACR Workflow

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How Should You Manage Skin Changes Over a Hemodialysis Access Site? An ACR Workflow

A 67-year-old patient with end-stage renal disease arrives for his scheduled hemodialysis session. The dialysis nurse calls you to evaluate the patient’s arteriovenous (AV) fistula, noting a new, tender, pulsatile 3 cm mass at a frequent cannulation site. The overlying skin is markedly thinned, shiny, and has a small, dark eschar at its center. You are concerned about a pseudoaneurysm with impending rupture or a localized infection. The immediate question is not just what to diagnose, but what is the safest and most definitive next step to prevent a catastrophic outcome. This article provides a detailed clinical workflow for this specific scenario, guiding you through the differential diagnosis and the rationale for the American College of Radiology (ACR) recommendations. For this presentation, the ACR Appropriateness Criteria state that an immediate Surgical consultation is Usually appropriate.

Who Fits This Clinical Scenario for Dialysis Access Complications?

This guidance applies to patients with an established upper or lower extremity hemodialysis access (either an arteriovenous fistula or graft) who present with concerning physical changes of the overlying skin at or near a cannulation site.

Inclusion criteria for this workflow include any of the following signs:

  • Marked skin thinning: The skin appears atrophic, shiny, or translucent over the access.
  • Ulceration or eschar formation: There is a breakdown of the skin surface or a dark, necrotic scab.
  • Spontaneous bleeding or oozing: Blood is present at the site without recent cannulation or trauma.
  • Pseudoaneurysm formation: A new, often tender and pulsatile, contained rupture of the vessel wall.
  • Superficial or deep infection: Signs include erythema, warmth, tenderness, purulent drainage, or abscess formation.

It is crucial to distinguish this scenario from other forms of access dysfunction. This workflow is not intended for:

  • Patients with only physiologic signs of dysfunction: If the primary issue is elevated venous pressures, prolonged bleeding after needle removal, decreased thrill, or difficulty with cannulation due to stenosis without the skin changes listed above, a different diagnostic pathway is indicated.
  • Patients with suspected acute thrombosis: A patient presenting with a sudden loss of the palpable thrill and audible bruit requires an urgent evaluation for thrombosis, which follows a separate ACR variant.
  • Patients with a new fistula that has failed to mature: An AV fistula that is not usable for dialysis within 2-3 months of creation represents a maturation failure, a distinct clinical problem.

What Diagnoses Are You Working Up with These Skin Changes?

The skin changes in this scenario are alarm signals for potentially limb- or life-threatening conditions involving the dialysis access. The differential diagnosis is narrow but includes several high-acuity problems that demand prompt evaluation and management.

Pseudoaneurysm This is a primary concern, especially with a new pulsatile mass. A pseudoaneurysm, or false aneurysm, is a hematoma resulting from a leak in the vessel wall that is contained only by the surrounding tissue or adventitia. Repeated needle trauma at the same site can weaken the fistula or graft wall, leading to its formation. The major risk is rupture, which can cause massive, difficult-to-control hemorrhage. The thinning of the overlying skin is a sign that this containment is failing.

Access Infection (Cellulitis, Abscess, Graft Infection) Infection is another critical consideration. It can range from a superficial cellulitis to a deep abscess or, in the case of an arteriovenous graft (AVG), infection of the prosthetic material itself. Graft infections are particularly dangerous as they often require complete excision of the graft material for source control. An infected pseudoaneurysm (mycotic aneurysm) carries an extremely high risk of rupture and sepsis.

Aneurysmal Degeneration Unlike a pseudoaneurysm, a true aneurysm involves the dilation of all three layers of the vessel wall. Over years of high-flow, high-pressure conditions, a mature fistula can develop true aneurysmal segments. While often stable for long periods, rapid expansion, pain, or overlying skin compromise indicates an increased risk of rupture and warrants the same urgent evaluation.

Skin Ischemia and Necrosis In some cases, the skin changes are not from direct vessel pathology but from compromised blood supply. This can be due to chronic pressure from a large underlying aneurysm or severe arterial “steal” syndrome diverting blood flow from the distal extremity. This leads to non-healing ulcers and eschar, which can serve as a portal for secondary infection.

Why Is Surgical Consultation the Primary Recommended Step?

The ACR Appropriateness Criteria rate Surgical consultation as Usually appropriate and the primary action for this scenario. This recommendation prioritizes clinical assessment and readiness for intervention over initial diagnostic imaging because the conditions on the differential are surgical problems that may require immediate intervention.

The rationale is based on urgency and the need for a definitive management plan. A surgeon can assess the stability of the lesion, the viability of the overlying skin, and the presence of infection at the bedside. This clinical evaluation is often sufficient to determine the need for emergent or urgent operative intervention, such as pseudoaneurysm repair, access ligation, or incision and drainage. Delaying this consultation to obtain imaging can consume critical time, especially if the access is at high risk of rupture.

Let’s review the ACR’s ratings for other potential actions in this context:

  • Placement of a new tunneled dialysis catheter is also rated Usually appropriate. This is not a diagnostic step but a crucial part of the management plan. The compromised access is considered unusable and unsafe. To ensure the patient can receive life-sustaining dialysis, a new, stable access (typically a central venous catheter) must be placed concurrently while the primary problem is being addressed.
  • Fluoroscopy fistulography hemodialysis access with intervention is rated May be appropriate. A fistulogram is excellent for identifying underlying stenoses or characterizing anatomy, but it is not the best initial step. In the setting of a suspected unstable pseudoaneurysm, injecting contrast could precipitate rupture. More importantly, the procedure is diagnostic and therapeutic for stenoses but does not address the skin integrity or a deep infection. It is a tool the surgeon or interventionalist may use as part of the overall treatment plan, not as the first-line diagnostic test.
  • Continued hemodialysis access use with surveillance is rated Usually not appropriate. This is the most critical point: attempting to cannulate a fistula or graft with the described skin changes is extremely dangerous. It risks catastrophic hemorrhage from a ruptured pseudoaneurysm or seeding the bloodstream with bacteria from an infected site. The access must be rested immediately.

Since the primary recommendation is a clinical consultation, there are no associated radiation or contrast risks with this initial step.

What Happens After the Surgical Consult? Downstream Workflow

The surgeon’s evaluation will direct the subsequent workflow, which is often rapid and decisive. The pathway diverges based on the suspected diagnosis and its acuity.

  • If a high-risk pseudoaneurysm or unstable aneurysm is confirmed: The patient will likely be admitted for urgent surgical intervention. This may involve open repair, placement of a covered stent-graft, or ligation of the access if it is unsalvageable. A new tunneled catheter will be placed for immediate dialysis needs.
  • If a deep infection or abscess is diagnosed: The patient will require urgent incision and drainage. If a graft is involved, the infected segment or the entire graft may need to be excised. Intravenous antibiotics are a critical adjunct, but source control is the priority. The access will be sacrificed, and a new catheter will be placed.
  • If the findings are less urgent (e.g., a stable, small aneurysm with mild skin thinning or a superficial cellulitis): The surgeon may opt for a more conservative approach. This could include local wound care, a course of oral or intravenous antibiotics, and strict instructions to avoid cannulation in the affected area (“resting the site”). The surgeon will then likely schedule an outpatient duplex ultrasound or fistulogram to evaluate the underlying access anatomy and plan for an elective revision or repair.
  • If the surgical consult rules out an urgent issue: If the surgeon determines there is no impending rupture or deep infection, the focus may shift. The patient might be referred for advanced wound care, and the nephrology and dialysis teams will work on a long-term access plan, which could involve creating a new fistula or graft elsewhere.

Common Pitfalls to Avoid in Managing Compromised Dialysis Access

Navigating this clinical scenario requires vigilance to avoid common and potentially harmful mistakes.

  • Pitfall 1: Delaying consultation for imaging. Ordering a routine outpatient duplex ultrasound for a patient with a tender, pulsatile mass and skin eschar is a critical error. The primary step is clinical evaluation by a specialist who can intervene.
  • Pitfall 2: Underestimating skin changes. Do not dismiss “shiny” or “thin” skin over an access as a benign finding. These are often the only external signs of an impending rupture of an underlying aneurysm or pseudoaneurysm.
  • Pitfall 3: Permitting “one last” cannulation. Under no circumstances should a compromised access site be cannulated. The risk of hemorrhage or sepsis is unacceptably high. The dialysis session must be deferred until a safe, alternative access is established.

Escalation: If the patient presents with spontaneous, uncontrolled bleeding from the access site, a rapidly expanding mass, or systemic signs of infection like fever and hypotension, this is a medical emergency. This requires immediate transfer to an emergency department for hemorrhage control and emergent surgical intervention.

Related ACR Topics and Tools

This article focuses on a single, high-acuity scenario. For a comprehensive overview of imaging for all types of access dysfunction, from low flow to thrombosis, please consult our parent guide. Additional tools can help you apply these standards in your practice.

Frequently Asked Questions

Can I order a duplex ultrasound first to confirm a pseudoaneurysm before calling surgery?

While ultrasound is an excellent diagnostic tool, the clinical presentation of a pulsatile mass with overlying skin changes is often sufficient to warrant an urgent surgical evaluation. Delaying consultation for imaging can be risky if the pseudoaneurysm is unstable. The surgeon will frequently perform their own bedside ultrasound or may proceed directly to the operating room based on the physical exam alone.

What if the skin is just shiny and thin, but there’s no ulcer or bleeding yet?

This still warrants prompt evaluation. Marked skin thinning, sometimes called ‘paper skin,’ is a significant warning sign of an impending rupture of an underlying aneurysm or pseudoaneurysm. This finding should be urgently communicated to the surgical or interventional team responsible for the access. Cannulation in or near that specific area must be avoided until the site is cleared by a specialist.

Is a CT angiogram (CTA) useful in this scenario?

A CTA is generally not a first-line study for this acute presentation. It exposes the patient to radiation and intravenous contrast and rarely changes the immediate management, which is clinical evaluation by a surgeon. A CTA may be used in more complex cases for preoperative planning, but this decision is typically made by the surgical team after they have assessed the patient.

The patient has a fever and redness around the access site. Should I start antibiotics before the surgical consult?

Yes. If there are clear signs of local or systemic infection, it is appropriate to obtain blood cultures and initiate empiric broad-spectrum antibiotics that cover common skin flora, including MRSA, based on local institutional guidelines. However, starting antibiotics should not delay the urgent surgical consultation, as source control—such as drainage of an abscess or excision of an infected graft—is the most critical component of treatment.

Why is ‘Placement of a new tunneled dialysis catheter’ also rated ‘Usually appropriate’?

This is rated ‘Usually appropriate’ because the existing, compromised access is considered unsafe to use. To continue life-sustaining hemodialysis, the patient requires a new, reliable access point immediately. Placing a tunneled central venous catheter is a crucial part of the overall management plan that is executed in parallel with addressing the primary problem with the fistula or graft.

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