WARFARIN AND SURGERY

1
WARFARIN AND SURGERY

• Venous thromboembolic disease - acute and chronic
• Atrial Fibrillation low vs high risk
• Mechanical Prosthetic Valves

2
RISK OF AN EVENT

• If warfarin ceased then
• Risk of recurrence greatest after acute venous TE
  episode 50 in first 3 months
• Less for chronic venous TE disease
• Risk for non valvular AF 4.5/yr of emboli
• Higher in AF and rheumatic heart disease
• Mechanical heart valves arterial TE AT 8

3
ANTICOAGULATIONand SURGERY

• No standard approach individualise
• Quantify the level of risk of thrombosis vs
  bleeding
• 4 days for INR to reach 1.5 when warfarin stopped
• about 3 days for INR to reach 2 when restarted
• sub therapeutic INR for 2 days before and about 2
  days after surgery

4
ANTI-PLATELET THERAPY

• Aspirin and clopidogrel
• After angioplasty and stent implantation
• Coated stents cant stop for at 2-3 months
• Bare stents cant stop for at least 1 month
• Risk of subacute stent thrombosis
• Preferable 12 days before elective surgery
• May require platelet transfusion

5
ORAL THROMBIN INHIBITOR

• Likely to replace Warfarin
• No need for INR mesurements
• Predictable degree of anticoagulation
• Free of interactions
• Astra product Ximelagatran, Exanta
• Recent large Trial in AF SPORTIF 111

6
PERIOPERATIVE MANAGEMENT

• Stop Warfarin 4- 5 days before surgery
• Measure INR daily
• When under 2 start low mwt heparin
• Stop day of surgery
• Resume warfarin as soon as possible
• Resume heparin following haemostasis
• Continue until INR gt2

7
RISK OF BLEEDING with HEPARIN

• Pre op, two day course of bleeding is low
• Up to 11 risk of bleeding over 2 days after
  surgery
• Heparin should not be restarted until 12 hours
  after op

8
TIPS on VIT K USE

• If used difficult to restart Warfarin
• Vit K can be given in small doses and is absorped
  bucally
• Avoid FFP if at all possible
• Can operate on most patients with INR lt 1.5