Should Anticoagulants Be Held Prior to AVF Creation?
Yes, anticoagulants should be held prior to arteriovenous fistula (AVF) creation for hemodialysis access, as the bleeding risk outweighs any potential benefit for thrombosis prevention in this specific surgical context.
Rationale for Holding Anticoagulation
AVF creation is classified as a low to moderate bleeding risk procedure where local hemostasis can be challenging due to the high-flow vascular anastomosis being created. The evidence demonstrates that:
Intraoperative systemic heparin provides no benefit for 30-day patency rates in AVF surgery (92% vs 86% patency with or without heparin, p=0.65), while increasing bleeding complications 1
Perioperative anticoagulation increases bleeding without improving outcomes: A prospective randomized study showed that systemic heparin during AVF creation resulted in significantly more early postoperative bleeding complications (p<0.01) with no improvement in 6-week primary patency (96% vs 92%, p=0.46) 2
The bleeding complications from anticoagulation during AVF surgery include hematomas, which can compress the newly created fistula and lead to early thrombosis—the exact outcome you're trying to prevent 3, 1
Specific Management Protocol
For Patients on DOACs (Apixaban, Rivaroxaban, Edoxaban, Dabigatran):
- Hold DOACs for 1-2 days before surgery depending on bleeding risk assessment and renal function 4
- For standard AVF creation (low-moderate bleeding risk): discontinue 1 day prior 4
- No bridging anticoagulation is required for AVF surgery 4
- Resume DOACs 1 day after surgery once adequate hemostasis is confirmed 4
For Patients on Warfarin:
- Stop warfarin 2-4 days before the procedure to allow INR to fall below 1.5 5
- No bridging with heparin is necessary for this procedure 5
- Restart warfarin within 24 hours after surgery once bleeding stability is assured 5
Critical Exception - High Thrombotic Risk Patients:
For patients with mechanical heart valves (particularly mitral position or any mechanical valve with additional risk factors):
- These patients require bridging anticoagulation when warfarin is interrupted 5
- Use therapeutic intravenous unfractionated heparin or low-molecular-weight heparin when INR falls below 2.0 5
- Stop bridging heparin 4-6 hours before AVF surgery 5
- This represents a genuine clinical dilemma where you must balance stroke risk against surgical bleeding
Common Pitfalls to Avoid
Do not continue anticoagulation "just to be safe" for thrombosis prevention—the data clearly shows this increases bleeding without improving fistula patency 1, 2. The primary determinant of early AVF failure is vessel diameter and quality, not perioperative anticoagulation status 3.
Do not use "bridging" heparin for atrial fibrillation patients undergoing AVF creation—this is unnecessary and increases bleeding risk. The brief interruption of anticoagulation (1-3 days) poses minimal stroke risk compared to the bleeding complications 4.
Avoid restarting anticoagulation too early—wait until there is clear evidence of hemostasis, typically 24 hours postoperatively, as premature resumption can cause hematoma formation that compromises the fistula 4, 2.