Subcutaneous enoxaparin is currently the gold standard for VTE chemoprophylaxis. However, the efficacy of chemoprophylaxis with subcutaneous enoxaparin is affected by patient-level factors, thus, resulting in VTE events despite guideline-compliant prophylaxis. A population at particular risk is the growing number of patients who undergo autologous breast reconstruction. Direct oral anticoagulants (DOAC) might be a less invasive, yet, more efficacious mode of chemoprophylaxis in this patient population. Hence, the proposed work has the potential to cause a paradigm shift in chemoprophylaxis guidelines in a large population of patients undergoing plastic surgery.

Inclusion Criteria:

• Adult (>18 years) women
• Scheduled to undergo unilateral or bilateral microsurgical breast reconstruction with free abdominal flaps (i.e. muscle-sparing transverse rectus abdominis musculocutaneous [TRAM] and/or deep inferior epigastric artery perforator [DIEP]) flap)
• Caprini score of 6 or greater.
• Ability to understand and the willingness to sign a written informed consent document.

Exclusion Criteria:

• Contraindication to the use of apixaban or enoxaparin
• Active bleeding
• History of bleeding disorder
• History of coagulopathy
• History of heparin-induced thrombocytopenia
• History of liver disease
• History of renal disease (creatinine clearance <30 mL/min; serum creatinine >1.6 mg/dL)
• Major neurosurgical intervention (brain/spine) within the past 90 days
• Ophthalmologic procedure within the past 90 days
• Uncontrolled hypertension
• History of alcohol and/or substance abuse
• Need for therapeutic anticoagulation
• Pregnant or Nursing

Adverse event data was collected for 90 days from the surgery date.