From the Research
Therapeutic anticoagulation is not routinely recommended for a clotted arteriovenous (AV) fistula, as the primary management approach is prompt referral for endovascular or surgical thrombectomy to restore patency. The use of systemic anticoagulation with medications like heparin, warfarin, or direct oral anticoagulants has not been shown to effectively restore flow in an already clotted fistula and may increase bleeding risk without clear benefit, as noted in the most recent and highest quality study available 1.
Key Considerations
- Time is critical when dealing with a clotted fistula, as successful salvage rates decrease significantly after 48 hours of thrombosis.
- If a clotted AV fistula is suspected (indicated by absence of thrill or bruit, pain, swelling, or inability to use for dialysis), immediate contact with the vascular access team or interventional nephrology service for urgent evaluation is necessary.
- While waiting for intervention, the arm with the fistula should be kept elevated to reduce swelling.
- The underlying cause of thrombosis should be investigated to prevent recurrence after intervention, which may include stenosis, hypotension, excessive compression, or hypercoagulable states.
Evidence Summary
The most recent study from 2024 1 provides a comprehensive review of interventions for thrombosed haemodialysis arteriovenous fistulas and grafts, highlighting the lack of evidence supporting the use of therapeutic anticoagulation for clotted AV fistulas. Other studies, such as those from 2020 2, focus on the outcomes of endovascular salvage of clotted arteriovenous access and predictors of patency after thrombectomy, further emphasizing the importance of prompt intervention over anticoagulation.
Clinical Approach
Given the current evidence, the focus should be on prompt restoration of patency through endovascular or surgical means rather than on therapeutic anticoagulation. This approach prioritizes the restoration of function to the AV fistula, minimizing the risk of further complications and the need for temporary catheter placement, which is associated with higher risks of infection and other adverse outcomes.