Should blood thinners be continued perioperatively for an Arteriovenous (AV) fistula?

Should Blood Thinners Be Continued Perioperatively for AV Fistula Surgery?

Blood thinners should generally be discontinued before AV fistula creation or revision surgery, with timing based on the specific agent and bleeding risk, though aspirin may be continued in select high-risk cardiovascular patients. 1

Antiplatelet Agents

Aspirin Management

• Discontinue aspirin 7-10 days before AV fistula surgery in patients with low cardiovascular risk 2
• Continue aspirin perioperatively in patients with moderate-to-high cardiovascular risk (recent coronary stents, known coronary artery disease, cerebrovascular disease), as the thrombotic risk outweighs bleeding risk 1, 2
• Resume aspirin 12-24 hours postoperatively once adequate hemostasis is achieved 3, 2

P2Y12 Inhibitors (Clopidogrel, Prasugrel, Ticagrelor)

• Stop clopidogrel 5 days before surgery 3, 2
• Stop prasugrel 7 days before surgery 3, 2
• Stop ticagrelor 3-5 days before surgery 3
• Resume within 12-24 hours postoperatively when hemostasis is secure 2

Special Considerations for Coronary Stents

• For bare-metal stents: defer elective AV fistula surgery for at least 6 weeks after stent placement 1, 2
• For drug-eluting stents: defer elective surgery for at least 6-12 months after placement 1, 3, 2
• If surgery cannot be delayed, continue dual antiplatelet therapy (aspirin plus P2Y12 inhibitor) perioperatively despite increased bleeding risk, as stent thrombosis carries catastrophic mortality 1, 2

Anticoagulants

Warfarin

• Discontinue warfarin 5 days before AV fistula surgery 3
• Resume 12-24 hours postoperatively if bleeding risk is acceptable 1
• Bridging with heparin or low-molecular-weight heparin is recommended for high-risk patients (mechanical heart valves, atrial fibrillation with high CHADS2 score) 1

Direct Oral Anticoagulants (DOACs)

• Stop DOACs 2-5 days before surgery depending on renal function and specific agent 3
• These agents lack immediate reversal options, making preoperative discontinuation critical 1

Intraoperative Considerations

• Intraoperative heparin administration during AV fistula creation significantly reduces early thrombosis (11% vs 25% without heparin, p=0.01) and improves short-term patency 4
• This represents prophylactic anticoagulation during the procedure itself, not continuation of chronic anticoagulation 4

Critical Pitfalls to Avoid

• Do not continue therapeutic anticoagulation perioperatively for AV fistula surgery, as it increases bleeding complications without proven benefit for access patency 1
• Antiplatelet agents after AV fistula thrombectomy actually worsen outcomes: they increase recurrent thrombosis requiring repeat intervention (HR 1.69) and reduce fistula longevity (HR 1.79) 5
• Inadequate communication about timing of medication discontinuation leads to preventable complications 6
• Failing to identify patients with recent coronary stents who require continued dual antiplatelet therapy despite bleeding risk 1

Postoperative Management

• Resume anticoagulation and antiplatelet agents 12-24 hours postoperatively once hemostasis is confirmed 1, 3, 2
• For urgent resumption of P2Y12 inhibitors, consider loading dose of clopidogrel 300-600 mg for rapid effect 3, 2
• Balance thrombotic risk against the specific bleeding risk of AV fistula surgery, which is generally moderate 1