What is the recommended approach for anticoagulant (Anti-Coagulant) bridging in patients undergoing thyroid surgery who are on long-term anticoagulation therapy, such as warfarin (Warfarin) or direct oral anticoagulants (DOACs) like apixaban (Apixaban) or rivaroxaban (Rivaroxaban)?

Anticoagulant Bridging for Thyroid Surgery

For patients undergoing thyroid surgery who are on long-term anticoagulation, heparin bridging therapy should be reserved only for patients at high thromboembolic risk and a minority of patients at intermediate risk, while most patients can safely have their anticoagulants temporarily discontinued without bridging. 1

Risk Assessment Algorithm

Step 1: Assess Procedural Bleeding Risk

Thyroid surgery is generally considered a procedure with moderate-to-high bleeding risk:

• Typically involves surgery duration >45 minutes
• Has potential for significant vascular involvement
• Requires meticulous hemostasis to avoid airway compromise

Step 2: Assess Patient Thromboembolic Risk

Categorize patients based on their indication for anticoagulation:

High Risk (consider bridging):

• Mechanical mitral valve
• Recent VTE (within 3 months)
• Recent stroke/TIA (within 3 months)
• Atrial fibrillation with CHADS₂ score ≥5

Moderate Risk (individualized approach):

• Bileaflet aortic valve with additional risk factors
• Atrial fibrillation with CHADS₂ score 3-4
• Recent VTE (3-12 months ago)

Low Risk (no bridging needed):

• Atrial fibrillation with CHADS₂ score 0-2
• VTE >12 months ago
• Bileaflet aortic valve without risk factors

Management Protocol

For Warfarin Patients:

1. Discontinuation:

   • Stop warfarin 5 days before surgery
   • Aim for INR <1.5 on day of procedure

2. Bridging (only for high-risk and selected moderate-risk patients):

   • Start LMWH (e.g., enoxaparin) at therapeutic dose when INR falls below therapeutic range
   • Last dose of LMWH should be 24 hours before surgery (use half the therapeutic dose)

3. Resumption:

   • Restart warfarin 12-24 hours post-surgery if adequate hemostasis achieved
   • For high bleeding risk procedures like thyroid surgery, delay resumption of therapeutic-dose LMWH for 48-72 hours 1
   • Consider prophylactic LMWH dose initially, then step up to therapeutic dose

For DOAC Patients (Apixaban, Rivaroxaban):

1. Discontinuation:

   • Stop DOAC 2-3 days before surgery (longer if renal impairment)
   • For apixaban, discontinue at least 48 hours prior to thyroid surgery 2

2. Bridging:

   • Bridging therapy is generally not needed for DOACs due to their short half-lives 1
   • Exception: patients who cannot tolerate oral medications postoperatively

3. Resumption:

   • For thyroid surgery (moderate-high bleeding risk): Resume DOACs 48-72 hours postoperatively 3
   • Consider starting with prophylactic dose for first 2-3 days (e.g., apixaban 2.5mg BID) before resuming full therapeutic dose 3

Important Considerations

• Avoid simultaneous anticoagulants: Never overlap LMWH bridging with DOAC resumption as this significantly increases bleeding risk 3

• Postoperative monitoring: Check surgical site every 30 minutes initially and monitor vital signs regularly 3

• Renal function: Monitor postoperatively as surgical procedures may affect renal function and impact DOAC dosing 3

• Elderly patients: Patients >80 years require careful monitoring due to increased bleeding risk and potentially reduced renal function 3

• Reversal options: For emergency situations, have reversal strategies available (prothrombin complex concentrate for warfarin; andexanet alfa for factor Xa inhibitors) 4

Common Pitfalls to Avoid

1. Unnecessary bridging: Bridging therapy increases bleeding risk without clear benefit in low-risk patients 1

2. Premature resumption: Restarting full-dose anticoagulation too early after thyroid surgery can lead to neck hematoma and airway compromise

3. Delayed resumption: Waiting too long to restart anticoagulation increases thromboembolic risk

4. One-size-fits-all approach: Failure to stratify patients based on individual thromboembolic and bleeding risks

5. Overlooking drug interactions: Certain medications may interact with anticoagulants and require dose adjustments 3

By following this structured approach to perioperative anticoagulation management for thyroid surgery, clinicians can minimize both thromboembolic and bleeding complications, optimizing patient outcomes.