Does a patient with polycythemia require medical clearance before surgery to minimize the risk of perioperative complications, particularly thrombosis and bleeding?

Medical Clearance for Polycythemia Vera Patients Before Surgery

Yes, patients with polycythemia vera absolutely require medical clearance and preoperative optimization before elective surgery to minimize the substantial risks of both thrombosis and bleeding. 1

Why Medical Clearance is Essential

Patients with polycythemia vera (PV) face significantly elevated perioperative risks despite optimal management. In a retrospective analysis of 105 PV patients undergoing surgery, 7.7% experienced vascular occlusion and 7.3% suffered major hemorrhage, even when 74% received cytoreductive therapy and antithrombotic prophylaxis. 1 Venous thrombotic events were particularly frequent in PV patients (7.7% vs 1.1% in essential thrombocythemia patients). 1

Mandatory Preoperative Requirements

Hematologic Control (3-Month Timeline)

For elective surgery, hematocrit must be controlled for 3 months prior to the procedure, with normalization or near-normalization of complete blood count without causing prohibitive cytopenias. 1

• Maintain hematocrit <45% through phlebotomy and/or cytoreductive therapy 1, 2
• Additional phlebotomy may be necessary immediately before surgery to ensure hematocrit remains <45% 1
• Initiate or optimize cytoreductive therapy if not already done 1

Multidisciplinary Team Assessment

Multi-disciplinary management with surgical and perioperative medical teams is recommended, including comprehensive review of bleeding and thrombosis history and current medication list. 1

The team should include:

• Hematologist/oncologist for disease optimization 1
• Surgeon to assess procedure-specific bleeding risk 1
• Anesthesiologist for perioperative planning 1

Coagulation Assessment

Coagulation tests to evaluate for acquired von Willebrand disease and other coagulopathies are recommended for patients undergoing high-risk surgical procedures, especially those with elevated platelet counts and/or splenomegaly. 1

This is critical because extreme thrombocytosis (platelet count ≥1000 × 10⁹/L) can cause acquired von Willebrand disease, paradoxically increasing bleeding risk. 2

Perioperative Medication Management

Aspirin

• Discontinue aspirin one week prior to surgery 1
• Restart 24 hours after surgery or when bleeding risk is acceptable 1

Anticoagulant Therapy

• Withhold anticoagulant therapy based on the half-life/type of agent prior to surgery 1
• Restart after surgery when bleeding risk is acceptable 1
• For vitamin K antagonists, stop approximately 5 days before surgery 1

Cytoreductive Therapy

Cytoreductive therapy (hydroxyurea or interferon) can be continued throughout the perioperative period unless unique contraindications are expressed by the surgical team. 1

High-Risk Surgical Procedures Requiring Extra Vigilance

The thrombotic and bleeding risk of the surgical procedure should be strongly considered, particularly for orthopedic and cardiovascular surgery. 1

For high venous thromboembolism risk procedures (cancer surgery, splenectomy, orthopedic and cardiovascular surgery):

• Extended prophylaxis with low molecular weight heparin (LMWH) should be considered 1
• Prophylaxis with aspirin may be considered following vascular surgery 1

Emergency Surgery Considerations

Emergency surgery should be performed as necessary with close postoperative surveillance for symptoms of arterial or venous thrombosis and bleeding. 1

While the 3-month optimization period cannot be achieved in emergencies, immediate hematocrit control and thromboprophylaxis remain critical. 3

Common Pitfalls to Avoid

• Proceeding with elective surgery without adequate hematologic control - This substantially increases thrombotic risk, particularly venous thromboembolism 1
• Failing to assess for acquired von Willebrand disease in patients with extreme thrombocytosis - This can lead to unexpected severe bleeding 1, 2
• Stopping cytoreductive therapy unnecessarily - Hydroxyurea can typically be continued perioperatively 1
• Inadequate thromboprophylaxis for high-risk procedures - PV patients require extended LMWH prophylaxis for orthopedic and cardiovascular surgeries 1
• Restarting aspirin too early - Wait until adequate hemostasis is achieved, typically 24 hours postoperatively 1

Risk Stratification Context

Patients with PV are at inherently high risk for thrombosis, with 16% experiencing arterial thrombosis and 7% experiencing venous thrombotic events prior to or at diagnosis. 2 The perioperative period compounds this risk through surgical stress, immobilization, and hemostatic activation. 4, 5