Rapid Lysis of Deep Vein Thrombosis by Low Molecular Weight Heparin

A 76-year-old man was evaluated for discomfort and swelling of the right lower leg 4 days after incision and drainage of an abscess on the plantar surface of the left foot due to osteomyelitis. The patient experienced discomfort on dorsiflexion of the right foot (Homans' sign) and on direct posterior-to-anterior compression of the right calf. Composite imaging of the right lower extremity by venous Doppler ultrasonography (Fig. 1A) revealed intraluminal echoes (small arrows) that indicated thrombus in the popliteal vein (left); this vessel could not be compressed because its lumen was occupied by thrombus (right).

Figure. A = artery; V = vein

The patient was treated with low molecular weight (LMW) heparin (60 mg administered subcutaneously every 12 hours) and warfarin (5 mg administered orally each day). Four days later, the discomfort and swelling of his right leg resolved rapidly. Follow-up venous ultrasonographic composite imaging of the right lower extremity (Fig. 1B) revealed a completely patent popliteal vein (left) that was now fully compressible (right). There was no evidence of proximal embolization because the patient's presenting symptoms improved. No new signs developed, nor were there any symptoms suggestive of acute pulmonary embolism. When the international normalized ratio (INR) reached 2.0, the LMW heparin was discontinued. The patient was discharged and instructed to continue wearing compression stockings and to keep taking oral warfarin for at least 3 months. He has experienced no recurrence in the 15 months since treatment.

Figure. A = artery; V = vein