From the Guidelines
A clot in an arteriovenous fistula poses a significant risk of complete blockage, leading to fistula failure, and necessitates immediate attention to prevent serious complications, including pulmonary embolism, heart, or brain complications, as highlighted in the 2023 study by 1 and 1. The primary risks associated with a clot in an arteriovenous fistula include:
- Complete blockage of the fistula, leading to fistula failure and loss of vascular access for dialysis patients
- Painful swelling, decreased blood flow to the hand, potentially leading to ischemia or tissue death
- Increased pressure in the fistula that may cause it to rupture
- Parts of the clot breaking off and traveling to the lungs, heart, or brain, causing life-threatening complications According to the study by 1, roughly 30% to 60% of AVFs experience thrombosis, and their restoration may be readily achieved using a combination of image-guided percutaneous interventional procedures, surgery, or some permutation of these therapeutic techniques. The study by 1 suggests that early diagnosis with the requisite intervention on the thrombosed hemodialysis access to restore its patency within 24 to 48 hours should be employed whenever achievable. Treatment typically involves prompt medical evaluation, anticoagulation therapy with medications like heparin, and possibly thrombectomy (surgical clot removal) or thrombolysis (clot-dissolving medications), as recommended by the SIR Standards and Practice Committee guidelines 1. Prevention strategies include:
- Regular fistula monitoring
- Proper compression after dialysis
- Maintaining good hydration
- Avoiding activities that compress the fistula Patients should be vigilant for warning signs such as decreased thrill (vibration), absence of bruit (sound), swelling, pain, or coolness in the extremity, and seek immediate medical attention if these occur, as emphasized by the 2023 study by 1 and 1.
From the Research
Risks of Having a Clot in an Arterovenous Fistula
The presence of a clot in an arterovenous fistula can lead to several complications, including:
- Thrombosis, which can cause fistula failure and require additional surgical interventions 2
- Inefficient dialysis due to recirculation, which can lead to inadequate removal of waste products from the blood 2
- High venous pressures, which can cause swelling, pain, and pigmentation in the affected limb 3
- Cardiac enlargement or cardiac insufficiency, although this is not commonly reported in patients with acquired arteriovenous fistulas after deep vein thrombosis 3
Prevention and Treatment of Clots in Arterovenous Fistulas
Several strategies can be employed to prevent and treat clots in arterivenous fistulas, including:
- Preservation of forearm veins by avoiding unnecessary venipunctures 2
- Use of antiplatelet drugs to prevent recurrent thrombotic episodes 2
- Intraoperative administration of heparin, although its effectiveness is still debated 4
- Thrombolysis with alteplase, which has been shown to be a safe and effective treatment for occluded arteriovenous fistulas and grafts 5
- Venous hypertension-relieving therapy, such as iliac vein stenting and Palma-Dale surgery, which can help to reduce symptoms and improve quality of life in patients with acquired arteriovenous fistulas after deep vein thrombosis 3