What is the management for a clot in a dialysis arm?

Management of Clot in Dialysis Access

Endovascular management is the preferred first-line therapy for thrombosed dialysis access, with intervention recommended within 24-48 hours to restore patency and preserve the access. 1

Initial Assessment

• Confirm thrombosis by physical examination (absent pulse and thrill)
• Determine type of access (AVF vs AVG)
• Assess for signs of infection (erythema, skin breakdown, purulent drainage)
• Check for swelling of the extremity (may indicate central venous stenosis)

Treatment Algorithm

First-Line Treatment: Endovascular Intervention

1. Diagnostic fistulography to identify underlying stenosis (90% of access thromboses are secondary to anatomic stenosis) 1

2. Percutaneous thrombectomy/thrombolysis:

   • Mechanical thrombectomy (suction thrombectomy, balloon thrombectomy, clot maceration)
   • Pharmacologic thrombolysis (alteplase 2mg in 2mL for catheter-directed thrombolysis) 2
   • Combination of techniques as needed

3. Balloon angioplasty of underlying stenosis:

   • Treat any stenosis >50% that is clinically significant
   • Particularly important for perianastomotic lesions in grafts 1

4. Consider stent placement in select cases:

   • Self-expanding stent-grafts preferred over bare metal stents
   • Indicated for recurrent stenosis or suboptimal results after angioplasty
   • Avoid placement in cannulation segments 1

Second-Line Treatment: Surgical Intervention

Consider surgical revision when:

• Endovascular treatment fails
• Thrombosis occurs >2 times within a single month
• Recurrent stenosis is identified in the circuit 1

Surgical options include:

• Manual thrombectomy
• Revision of the access
• Creation of a new access at a different site

Special Considerations

For AVF aneurysms/pseudoaneurysms contributing to thrombosis:

• Surgical approach may be needed for chronic intraluminal thrombus
• Consider incision near arterial anastomosis to facilitate arterial plug removal
• Manual "milking" of thrombus from access lumen (95% success rate) 1

Anticoagulation Management

• During thrombectomy procedures, heparin is typically administered
• For maintenance dialysis after successful declot:
  • Standard heparinization during dialysis (initial dose 5,000 units IV followed by continuous infusion) 3
  • Even patients on oral anticoagulants require additional heparin/LMWH during dialysis to prevent clotting 4

Temporary Access for Failed Declot

If declot is unsuccessful:

• Place a tunneled dialysis catheter for interim hemodialysis
• Preferably in the extremity opposite to the planned permanent access
• Allow for placement in femoral vein to preserve upper extremity vasculature 1

Prevention of Recurrent Thrombosis

• Regular monitoring and surveillance of access
• Weekly physical examination (inspection and palpation for pulse and thrill)
• Address underlying causes:
  • Hypotension post-hemodialysis
  • Hypercoagulable states (consider testing if recurrent thrombosis)
  • Decreased cardiac output
  • Access site infection 1

Expected Outcomes

• Clinical success rate for thrombolysis/thrombectomy: 75-94%
• 6-month primary patency: 18-39%
• 6-month secondary patency: 62-80%
• 12-month secondary patency: 57-69% 1

Early intervention is critical to maximize the chances of successful declot and to preserve the access for future use, as each thrombotic episode increases the risk of permanent access failure and the need for a new access creation.