Deep venous thrombosis: A review of the pathophysiology, clinical features, and diagnostic modalities

A 57-year-old man presented to the emergency room complaining of 2 hours of shortness of breath and chest pain. Two weeks before, he had a similar episode associated with swelling and pain of the left lower extremity. He was hospitalized and diagnosed with pulmonary embolism resulting from deep vein thrombosis (DVT) of the left thigh veins. Treatment consisted of intravenous heparin followed by chronic warfarin therapy. A ventilation-perfusion scan revealed new segmental defects consistent with recurrent pulmonary embolism. A Doppler ultrasound of the lower extremities showed a persistent left lower extremity DVT. He was treated with low-molecular-weight heparin and an inferior vena cava (IVC) filter was placed because of recurrent pulmonary embolism despite anticoagulation. Two days after the filter placement, the patient complained of dizziness upon standing. His blood pressure was 126/80 in supine position and decreased to 96/60 on standing. There was no change in hemoglobin and no evidence of bleeding. Intravenous fluids were administered but his orthostatic hypotension persisted. On the third day, swelling of his right lower extremity became evident. A computed tomogram of retroperitoneal region and pelvis showed a large thrombus in the IVC extending to the right iliac vein. A repeat Doppler ultrasound showed right iliofemoral DVT and a persistent thrombus in the left femoral vein. An infusion of tissue plasminogen activator was administered through a catheter placed in the IVC via the popliteal vein. Thrombus resolution was assessed by daily venograms. Four days after initiation of thrombolysis, there was significant resolution of the thrombus in the IVC and right iliofemoral system. The catheter was removed on the fifth day. Low-molecular-weight heparin was continued. His dizziness, orthostatic hypotension and the swelling in the right lower extremity subsided. The patient was subsequently sent to the rehabilitation unit where he made a complete recovery.