Which patient characteristic is associated with the highest risk of operative Venous Thromboembolism (VTE)?

Patient Characteristics Associated with Highest Risk of Operative Venous Thromboembolism

History of previous embolism is associated with the highest risk of operative venous thromboembolism according to risk assessment models. 1

Risk Factors for Operative VTE in Cancer Patients

The risk of venous thromboembolism (VTE) in surgical cancer patients is significantly elevated compared to non-cancer patients undergoing similar procedures. According to the evidence, cancer patients undergoing surgery have:

• Two-fold increased risk of postoperative DVT
• Three-fold greater risk of fatal PE compared to non-cancer surgical patients 1

Major Risk Factors (Ranked by Impact)

1. Prior history of VTE - strongest predictor of operative VTE risk 1
2. Active cancer - especially metastatic disease 1
3. Cancer type - highest risk in pancreatic, gastric, brain, ovarian, kidney, and lung cancers 1
4. Immobility - significant risk factor but not the highest 1
5. Fractures (including femur) - important but not the highest risk factor 1

Evidence Supporting Prior VTE as Highest Risk Factor

The ESMO guidelines specifically identify "prior history of VTE" as one of the most significant risk factors for developing operative VTE 1. This is consistent across multiple guidelines, with the American Society of Clinical Oncology guideline listing it as a key patient-related factor 1.

In the nested case-control study examining VTE risk factors in gynecological cancer surgery, prior VTE was associated with a 2.6-fold increased risk (OR 2.6; 95% CI 1.1,6.1) of developing postoperative VTE 2.

Other Important Considerations

Cancer-Specific Factors

Cancer patients have baseline hypercoagulability due to:

• Expression of procoagulant molecules by cancer cells
• Activation of host blood vascular cells
• Activation of endothelium by anticancer drugs 1

Perioperative Considerations

• Extended thromboprophylaxis (up to 1 month) is recommended for cancer patients undergoing major abdominal or pelvic surgery 1
• Pharmacologic prophylaxis with LMWH, UFH, or fondaparinux is standard of care 1

Clinical Implications

When assessing operative VTE risk in cancer patients, history of previous VTE should be given the highest weight in risk stratification. While other factors like cancer type, immobility, and fractures are important, they don't carry the same predictive value as prior VTE history.

For patients with a history of VTE undergoing cancer surgery, consider:

• More aggressive prophylactic anticoagulation regimens
• Extended duration of prophylaxis
• Closer postoperative monitoring
• Earlier mobilization when possible

Common Pitfalls to Avoid

1. Underestimating the significance of prior VTE history in preoperative risk assessment
2. Focusing only on the current surgical risk factors without considering patient history
3. Assuming all cancer types carry equal VTE risk
4. Discontinuing prophylaxis too early (especially in high-risk patients)
5. Relying solely on mechanical prophylaxis in patients with high-risk features

While all four factors mentioned in the question (history of embolism, femur fracture, history of cancer, and immobility) increase the risk of operative VTE, the evidence consistently identifies prior history of VTE as the strongest predictor.