Thromboprophylaxis in Orthopedic Surgeries - Guarding Against Clotting Complications

Introduction

Antithrombotic therapy is a very important part of orthopedic surgeries in the management of patients during and after the surgery. Venous thromboembolism (VTE) is one of the deadly complications associated with orthopedic surgeries. Other complications like deep vein thrombosis (DVT) and pulmonary embolism are also associated with orthopedic surgeries. To avoid such serious complications of venous thromboembolism, standard and optimal thromboprophylaxis therapy is now mandatory during orthopedic surgical procedures. There are several causes of venous thromboembolism, one of which is Virchow's triad. Virchow’s triad includes hypercoagulability, venous stasis, and damage to the endothelial lining. Based on the recent advances in the orthopedic surgical field, multiple approaches and guidelines have been developed for optimal thromboprophylaxis therapy after surgical procedures to prevent bleeding complications.

What Is Thromboprophylaxis?

After surgical procedures like orthopedic surgeries, there is an increased risk of thrombosis (blood clot formation) in the patients. Thromboprophylaxis is a medical procedure that involves a combination of mechanical and pharmacological therapies to prevent the formation of blood clots (thrombosis) in the legs or the lungs. Thromboprophylaxis therapy is usually recommended after surgical procedures.

What Are Various Methods of Thromboprophylaxis Therapy?

Different methods of thromboprophylaxis therapy that can be used during orthopedic surgeries are:

1. Mechanical Therapy: Mechanical therapies for preventing venous thromboembolism are graduated compression stockings (GCS), intermittent pneumatic compression devices (IPCD), mobilization therapy, and venous foot pumps.

Advantages of Mechanical Therapy:

• Decrease bleeding potential.

• Reduction in potential side effects.

• The need for lab monitoring can be avoidable.

Disadvantages of Mechanical Therapy: Difficulty in implementing the therapy because of low patient compliance. Mechanical therapy cannot be implemented for all cases (like open fracture, cardiac insufficiency, infections, etc.)

2. Pharmacological Therapy: Pharmacological therapy used for thromboprophylaxis in orthopedic surgeries includes different agents like:

• Aspirin: It is a widely accepted and quite inexpensive pharmacological agent used for venous thromboembolism prophylaxis. American Association of Orthopedic Surgery (AAOS) guidelines recommend Aspirin as the most potent agent for thromboprophylaxis.

• Low-Molecular-Weight-Heparin: Based on ACCP guidelines, low molecular weight heparin is used as a gold standard agent for thromboprophylaxis for preventing the risk of thromboembolism and deep vein thrombosis. Low molecular weight heparin is more effective in preventing bleeding complications associated with orthopedic surgeries as compared to warfarin.

• Warfarin: Warfarin is a vitamin K antagonist and is used commonly during orthopedic surgeries to prevent bleeding complications.

• Vitamin K Antagonist: Vitamin K antagonists are orally administered anticoagulants for thromboprophylaxis in orthopedic surgeries based on ACCP guidelines.

• Dabigatran: Dabigatran drug is approved by Food and Drug Administration (FDA) for venous thromboembolism thromboprophylaxis. The European Commission approved the drug Dabigatran for use in orthopedic surgery in March 2008.

• Rivaroxaban: The drug was approved by Food and Drug Administration (FDA) in July 2011 for thromboprophylaxis for venous thromboembolism.

• Factor Xa Inhibitors: Factor X inhibitors like Fondaparinux, Apixaban, and Dabigatran are other pharmacological agents used for thromboprophylaxis procedures.

What Are the Contraindications of Pharmacological Thromboprophylaxis?

Pharmacological thromboprophylaxis is contraindicated:

• Thrombocytopenia (low platelet levels).

• Patients with known bleeding disorders.

• Patients with uncontrolled hypertension (high blood pressure).

• Patient with recent hemorrhagic stroke.

What Are the Guidelines for Thromboprophylaxis in Orthopedic Surgeries?

Different guidelines for thromboprophylaxis in orthopedic surgeries were recommended by the American College of Chest Physicians (ACCP) and the National Institute of Health and Care Excellence (NICE) are:

• The ACCP guidelines recommend the use of LMWH (low molecular weight heparin), Aspirin, and Apixaban for a minimum of 10 to 14 days to 35 days for patients undergoing hip fracture surgery.

• Dual thromboprophylaxis with intermittent pneumatic compression device (IPCD) is recommended daily for 18 hours during hospitalization.

• For patients who are asymptomatic, no Doppler ultrasonography (DUS) is required.

• The NICE guidelines recommend the use of low molecular weight heparin for ten days followed by Aspirin for around 28 days for elective total hip replacement surgery.

• The NICE guidelines recommend the use of Apixaban and Dabigatran for thromboprophylaxis to prevent venous thromboembolism in patients undergoing total knee replacement surgeries or hip replacement surgeries.

• The incidence of deep vein thrombosis (DVT) after knee arthroscopy (a tiny camera used to see internal structures of the knee) is around 0.2 to 18 percent. NICE guidelines recommend using LMWH (low molecular weight heparin) for two weeks (14 days) for patients undergoing knee arthroscopic surgery (if anesthesia time is more than 90 days) to prevent the risk of bleeding.

• The ACCP guidelines recommend pharmacological thromboprophylaxis in patients undergoing isolated low-leg surgeries.

• Patients undergoing ankle and foot surgeries and upper limb surgery should undergo pharmacological thromboprophylaxis based on NICE guidelines to prevent bleeding tendencies during orthopedic surgeries.

• During the cast immobilization procedures (immobilization of fractured), patients should undergo thromboprophylaxis with low molecular weight heparin to prevent bleeding risk based on NICE guidelines.

• Patients with spinal cord injuries should undergo routine thromboprophylaxis procedures with low molecular weight heparin to prevent spinal hematoma.

Recommended Guidelines for Thromboprophylaxis in Patients with Risk of DVT:

The guidelines recommended to prevent the risk of DVT (deep vein thrombosis) depend on the estimated risk of DVT based on the type of orthopedic surgeries performed.

• Low Risk: If the estimated risk of DVT is less than 10 percent in cases of minor surgeries, then early ambulation can be done.

• Moderate Risk: If the estimated bleeding risk of DVT is 10 to 40 percent, then low molecular weight heparin, Fondaparinux, and mechanical thromboprophylaxis procedures should be used.

• High Risk: If 40 to 90 percent of the bleeding risk of DVT is estimated in cases like hip or knee surgery, then pharmacological and mechanical thromboprophylaxis procedures need to be performed.

Conclusion

Patients undergoing orthopedic surgeries have an increased risk of bleeding tendencies. Different mechanical and pharmacological therapies are used for thromboprophylaxis procedures in patients undergoing orthopedic surgeries. Various guidelines recommended by AACP and NICE for thromboprophylaxis in orthopedic surgeries should be implemented. Thromboprophylaxis helps to prevent the risk of bleeding and life-threatening complications such as deep vein thrombosis and venous thromboembolism (VTE). However, further understanding of different pharmacological and mechanical thromboprophylaxis therapy for orthopedic surgeries needs to be understood to implement them before and after orthopedic surgical procedures.