Management of Warfarin Prior to Cold Knife Cone Cervical Biopsy
Warfarin should be discontinued 5 days before a cold knife cone cervical biopsy, with INR checked prior to the procedure to ensure it is <1.5. 1
Risk Classification
- Cold knife cone cervical biopsy is considered a high-risk endoscopic/surgical procedure due to its potential for significant bleeding 1
- The management approach depends on the patient's thrombotic risk profile 1
Protocol for Patients at Low Thrombotic Risk
- Stop warfarin 5 days before the procedure 1
- Check INR prior to the procedure to ensure it is <1.5 1
- Resume warfarin on the evening of the procedure at the usual daily dose 1
- Check INR one week after the procedure to ensure adequate anticoagulation 1
Protocol for Patients at High Thrombotic Risk
- Stop warfarin 5 days before the procedure 1
- Two days after stopping warfarin, commence daily therapeutic dose of Low Molecular Weight Heparin (LMWH) 1
- Administer the last dose of LMWH at least 24 hours prior to the procedure 1
- Check INR prior to the procedure to ensure it is <1.5 1
- Resume warfarin on the evening of the procedure at the usual daily dose 1
- Restart daily therapeutic dose of LMWH on the day after the procedure 1
- Continue LMWH until a satisfactory INR is achieved 1
Risk Stratification
Low Thrombotic Risk Patients
- Patients without venous thromboembolic events for more than 3 months 1
- Patients with atrial fibrillation without history of stroke 1
- Patients with bileaflet mechanical valve in the aortic position 1
High Thrombotic Risk Patients
- Patients who have previously experienced a thromboembolic event 1
- Patients with mechanical cardiac valve in the mitral position 1
- Patients with older model cardiac valve (ball/cage) 1
Important Considerations
- All patients should be advised of the thrombotic risks of discontinuing warfarin and the hemorrhagic risks of continuing therapy 1
- Even when temporarily discontinued, warfarin therapy is associated with an increased risk of post-procedure bleeding compared to non-anticoagulated patients 1
- The INR should be monitored frequently after resuming warfarin to ensure it returns to the therapeutic range 2, 3
Common Pitfalls to Avoid
- Failing to check INR prior to the procedure to confirm it is <1.5 1
- Inadequate bridging with LMWH for high-risk patients 1
- Restarting warfarin too late after the procedure, which can delay return to therapeutic anticoagulation 1, 2
- Not providing clear instructions to patients about when to stop and restart medications 1