A 45-year-old male returns to clinic for follow-up examination. He has no current complaints and has been feeling well recently. Past medical history is significant for hypertension and gastroesophageal reflux disease. He also had a left knee operation eight months ago that was complicated by a postoperative deep vein thrombosis (DVT) of the left leg. He has no other personal history of blood clots, and there is no family history of clotting disorders. Currently, his vital signs are stable and his physical examination is within normal limits. Specifically, there is no swelling or calf tenderness of the left leg. He took warfarin on a daily basis for a total of six months after the DVT was diagnosed and then stopped taking it because he no longer wanted to deal with monitoring his INR. This is his first visit to clinic since being discharged after his knee operation. Which of the following is the next best step in treating this patient's prior DVT?

Question

A 45-year-old male returns to clinic for follow-up examination.  He has no current complaints and has been feeling well recently.  Past medical history is significant for hypertension and gastroesophageal reflux disease.  He also had a left knee operation eight months ago that was complicated by a postoperative deep vein thrombosis (DVT) of the left leg.  He has no other personal history of blood clots, and there is no family history of clotting disorders.  Currently, his vital signs are stable and his physical examination is within normal limits.  Specifically, there is no swelling or calf tenderness of the left leg.  He took warfarin on a daily basis for a total of six months after the DVT was diagnosed and then stopped taking it because he no longer wanted to deal with monitoring his INR.  This is his first visit to clinic since being discharged after his knee operation.  Which of the following is the next best step in treating this patient's prior DVT?

Quizplus · Accepted Answer

Explanation: In contrast to patients with idiopathic DVTs, patients with DVTs secondary to reversible or time-limited risk factors (eg, surgery, pregnancy, oral contraceptive use, or trauma) should be treated for at least three months but not longer than six months, as the risk of a recurrent DVT after six months of treatment is very low. In patients with idiopathic DVTs, at least six months of warfarin therapy is also recommended, with re-evaluation at the end of the treatment cycle for long-term anticoagulation. This decision is individualized and should be based on the risk to benefit ratio for anticoagulation. Because this particular patient's DVT occurred after a major surgery and he has no other personal or family history of venous thromboembolic disease, the six months of warfarin therapy he has already received is adequate treatment. He does not require further anticoagulation at this time. (Choice A and B)There is no need to initiate treatment with unfractionated or low-molecular weight heparin at this time, as this patient has no evidence of recurrent thromboembolic disease and has already received adequate anticoagulation. (Choice C) Because this patient's risk of a recurrent DVT after six months of warfarin therapy is very low (less than 3% in the first year), he requires no further anticoagulation. (Choice E)As there is no suspicion of a recurrent DVT at this time, a lower extremity venous scan is not likely to be helpful. Educational objective: In a patient who develops a DVT as a result of a reversible or time-limited risk factor (eg, surgery, pregnancy, oral contraceptive use, or trauma), warfarin anticoagulation should be continued for a minimum of three months. Treatment for longer than six months, however, is not necessary.

A 45-Year-Old Male Returns to Clinic for Follow-Up Examination