Review Question - QID 108624

A 27-year-old female presents to the ED with pain and swelling of her right lower extremity. The patient’s history is also significant for three spontaneous abortions. Due to the psychological distress of the abortions, she is currently on an OCP. The patient denies chest pain or shortness of breath. On exam, her right calf is erythematous and swollen with increased tenderness on passive dorsiflexion. A Doppler ultrasound is performed showing a deep venous embolism in her right lower extremity. She is given the appropriate anti-coagulant therapy. At this time, her platelet count is 250,000/mm^3. The patient returns 3 days later complaining again of right lower extremity pain that has now developed into the lesion shown in Figure A. A CBC is drawn with the following results:

Hemoglobin: 12.5 g/dL
Leukocyte count: 7,000/mm^3
Platelets: 154,000/mm^3

What is the next step in management?