Perioperative Management of Anticoagulation in Gynecologic Patients
Jan 2011 – by A. Burkett, MD
Women being treated with long-term anticoagulant therapy require a risk stratification, review of bleeding risk based on surgical procedure, and review of current anticoagulation therapy to determine the best perioperative management strategy. The clinician needs to determine whether stopping medications is warranted, the best time to stop medical therapy, whether bridging therapy is needed, and the best time to reinstitute anticoagulation postoperatively.
Women at highest risk for perioperative arterial or venous thromboembolism (VTE) include those with recent stroke, mitral valve prosthesis, older aortic valve prosthesis, severe thrombophilia, atrial fibrillation with CHADS2 (congestive heart failure-hypertension-age-diabetes-stroke) score of 5 or 6, and VTE within 3 months. Those at moderate risk include women with bileaflet aortic valve prosthesis with complicating factors, atrial fibrillation with CHADS2 score 3 or 4, non-severe thrombophilia (includes Factor V Leiden heterozygotes), active cancer, and VTE within 3-12 months of surgery. Low risk women are those with bileaflet aortic valve prosthesis with no complicating factors, atrial fibrillation with CHADS2 score of 0-2 and a single VTE that occurred greater than 12 months ago with no ongoing risk factors.
Experts agree that bridging therapy does increase the risk of post-operative bleeding complications and studies reveal that post-operative bleeding can lead to wound infection, need for blood transfusion and actually delay the restarting of anticoagulation. In gynecologic practice surgeries for cancer and those involving the bladder are considered the highest risk for bleeding.
Who should stop anticoagulation?
In general those undergoing major procedures should stop anticoagulation due to the risk of intraoperative and immediate postoperative bleeding complications. However, those undergoing minor procedures such as vulvar biopsy can generally continue anticoagulation.
In patients at high risk for thromboembolism, therapeutic bridging therapy is recommended with subcutaneous low molecular weight heparin (SC LMWH) or therapeutic intravenous unfractionated heparin (IV UFH). In those at moderate risk, use of therapeutic SC LMWH, therapeutic IV UFH or low dose SC LMWH is acceptable. In those at low risk for post operative thrombosis no bridging therapy is needed. SC LMWH is considered more cost-effective than IV UFH. Twenty-four hours prior to the procedure some dispense the last dose of LMWH at ½ the therapeutic dose. UFH should be stopped 4 hours prior to procedure. After minor procedures, bridging therapy can be restarted 24 hours after procedure, but should be delayed for 48 to 72 hours in those undergoing major surgery or when there is a high risk for post-operative bleeding. Monitoring of anti-factor-Xa levels is unnecessary when utilizing LMWH.
Vitamin K antagonists (VKA)
VKAs should be stopped approximately 5 days prior to procedure to time for the INR to normalize. VKA can then be restarted 12 to 24 hours after surgery as long as adequate homeostasis is present. Oftentimes it is acceptable to forego postoperative bridge therapy and simply restart VKA. In those requiring urgent surgery whose international normalized ratio (INR ) is still elevated use of IV or oral vitamin K is recommended. For emergent surgery fresh-frozen plasma can be added to the vitamin K therapy.
Antiplatelet therapy (aspirin, clopidogrel)
For patients at low risk for coronary events, antiplatelet therapy should be stopped at least 7 days prior to major gynecologic procedures. For those at high risk for coronary events, aspirin should be continued, but it is preferred to stop clopidogrel 5-10 days prior to the procedure. These can be restarted the morning following surgery. Bridging therapy is not recommended. Routine monitoring of platelet function is not required. Should urgent or emergent surgery be required, utilization of prohemostatic agents and platelet transfusion is suggested if there is a high risk of hemorrhage.
In women who have recently undergone cardiac revascularization with bare metal stents, elective procedures should be avoided for at least 2 weeks and preferably 6 weeks due to the high risk for thrombotic events during this time period. If surgery is required in patients with bare stents within the first 6 weeks of placement, antiplatelet medications should be continued. In those with a drug eluding stent who require surgery within the first 12 months, continuation of both aspirin and clopidogrel is recommended when feasible. Due to the paucity of data on the use of bridging therapy in those at high risk for bleeding complications that necessitate stopping antiplatelet therapy, it is not currently recommended.
Current insurance guidelines usually allow for 2-3 days of in hospital post-operative care following major open abdominal procedures. This is often reduced to 1 day when advanced laparoscopic techniques are utilized. Patients have continued risk for development of thrombosis after discharge from the hospital. Therefore warning signs of thrombotic events including venous thrombosis and stroke should be reviewed with the patient. Early post-operative assessment in the office setting should be considered in those at particularly high risk for complications.
Kraai EP, Lopes RD, Alexander JH, and Garcia D. Perioperative Management of anticoagulation: guidelines translated for the clinician J Thromb Thrombolysis (2009) 28: 16-22
Douketis JD et al. The Perioperative Management of Antithrombotic Therapy: American College of Chest Surgeons Evidence-Based Practice Guidelines (8th edition) Chest (2008) 133:299S-339S