What is the first‑line treatment for a thrombosed arteriovenous graft in a hemodialysis patient?

First-Line Treatment for Thrombosed Arteriovenous Graft

Endovascular intervention with mechanical thrombectomy and/or pharmacologic thrombolysis combined with balloon angioplasty is the first-line treatment for a thrombosed AV graft, and must be performed within 24-48 hours of diagnosis. 1, 2

Immediate Management Algorithm

Timing is Critical

• Intervene within 24-48 hours of thrombosis detection to maximize success rates and minimize need for temporary catheter placement 1, 2
• Delayed intervention beyond 48 hours significantly decreases success rates and necessitates emergency central venous catheter placement with associated infection risks 2

First-Line Endovascular Approach

The Society of Interventional Radiology establishes endovascular management as superior to open surgery for first-line therapy 1, 2. The procedure involves:

Step 1: Mechanical Thrombus Removal

• Use mechanical thrombectomy techniques including suction thrombectomy, balloon thrombectomy, or clot maceration 1, 2
• Pharmacologic thrombolysis with tissue plasminogen activator (TPA) can be combined with mechanical techniques 1, 2

Step 2: Mandatory Fistulography

• Perform fistulography immediately post-thrombectomy to identify underlying stenosis 1
• 85-90% of AV graft thromboses are caused by venous outflow stenosis 1, 2
• Failure to identify and treat the underlying stenosis results in rapid re-thrombosis 2, 3

Step 3: Treat the Underlying Stenosis

• Perform balloon angioplasty on any stenosis ≥50% diameter 1
• Residual stenosis must be <30% to meet technical success criteria 1
• Stent placement may be necessary for elastic recoil after angioplasty 1

Step 4: Perform as Outpatient Under Local Anesthesia

• The procedure should be completed as an outpatient intervention 1
• Use local anesthesia rather than general anesthesia 1

Expected Outcomes

Clinical Success Rates

• Immediate technical success: 85-93% 1
• Clinical success (at least one successful dialysis session): 75-94% 1, 2

Patency Benchmarks

• 3-month primary patency: 37-58% 1, 2
• 6-month primary patency: 18-39% 1, 2
• 6-month secondary patency: 62-80% 1, 2
• 1-year secondary patency: 57-69% 1

These benchmarks represent minimum acceptable goals for centers performing these procedures 1.

When to Escalate to Surgery

Refer for surgical thrombectomy or revision if:

• Endovascular treatment fails clinically 1, 2
• Thrombosis recurs >2 times within a single month 1, 2
• More than 2-3 interventions required within 1-3 months 1
• Aneurysms or pseudoaneurysms are present with chronic intraluminal thrombus difficult to access endovascularly 1

Surgical vs. Endovascular: The Evidence Divergence

While both NKF-K/DOQI and SIR guidelines state that either surgical or endovascular approaches are acceptable based on center expertise 1, the 2023 ACR guidelines explicitly state endovascular management is the preferred alternative to open surgery as first-line therapy 1. This represents an evolution in practice patterns, with endovascular techniques largely superseding open surgical techniques 1.

A 2019 meta-analysis found surgical thrombectomy had better long-term patency (1-year and 2-year primary patency) compared to wholly endovascular therapy 4. However, this conflicts with guideline recommendations prioritizing endovascular approaches first-line 1, 2. The practical resolution: start with endovascular intervention for its minimally invasive nature, outpatient feasibility, and ability to use the access immediately, then escalate to surgery for recurrent failures 1.

Critical Pitfalls to Avoid

• Never delay intervention beyond 48 hours - this decreases success rates and forces placement of temporary catheters with infection risk 1, 2
• Never skip the post-thrombectomy fistulography - 85% of thromboses have underlying venous stenosis that will cause immediate re-thrombosis if untreated 1, 2, 3
• Never accept residual stenosis >30% after angioplasty - this predicts early failure 1
• Never place multiple temporary catheters while awaiting definitive treatment - each catheter increases infection risk 1, 2

Additional Considerations

Evaluate for Non-Stenotic Causes (10% of cases)

• Hypotension post-hemodialysis 1, 2
• Hypercoagulable states - obtain thrombophilia testing if thrombosis recurs >2 times per month 1, 2
• Decreased cardiac output 1, 2
• Access site infection 1, 2

If Endovascular Declotting Fails

• Place a tunneled cuffed dialysis catheter for interim hemodialysis access (acceptable for <3 months duration) 1, 2
• Refer urgently for surgical revision or new access creation 1

Antiplatelet Therapy Warning

• Do not routinely initiate antiplatelet medications after surgical thrombectomy - a 2017 study found this significantly decreased graft longevity (adjusted HR 2.13) without preventing re-thrombosis 5