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To Filter or Not After Pulmonary Blood Clot Is Not a Simple Decision

Dear Dr. Roach: To filter or not to filter —that is the question.

I recently survived a Saddle Pulmonary Embolism. One pulmonologist recommended that a vena cava filter be put in place to help prevent damage from a future embolism. This recommendation was made since I am at high risk with a genetic disposition for blood clots. I have factor V Leiden.

Another pulmonologist did not recommend a filter unless the warfarin did not prevent a reoccurrence of blood clots. The filter itself has many risks.

Would you recommend having a filter installed? I am a 66-year-old man. The only symptom I had of the embolism was quick-onset shortness of breath. The heart and lung damage has repaired itself in the past few months. — R.L.

Answer: A “saddle” pulmonary embolism is a very large blood clot that goes into the blood vessels of the lungs and is large enough to sit across both pulmonary arteries. You are fortunate to have survived, since these often block all blood output from the right side of the heart into the lungs.

There is no disagreement that you would benefit from anticoagulants. Initially, I am sure you received heparin or enoxaparin (or similar injection agent). Pretty much every expert also would agree to give you warfarin, and given the severity, I think lifelong warfarin is appropriate.

The question you ask is about combination IVC filter and warfarin. An IVC filter is a metal cage that is inserted into the inferior vena cava, usually via a catheter inserted in the leg. The cage catches any blood clots coming from the legs or pelvis and prevents them from going into the lungs. By themselves, they are about 96 percent effective at preventing recurrence. The combination of both warfarin and an IVC filter is not recommended usually, but because of your factor V Leiden mutation (it increases your risk of further blood clotting) and the severity of your initial blood clot, I can understand why one of your doctors recommended both.

Warfarin alone is very effective for most people, and most recommendations are to not put in the filter. If you couldn’t take warfarin (for example, if you had a reaction to it, which is not uncommon), that would be an indication in favor of a filter. However, I agree with the second pulmonologist, who did not recommend a filter unless you get another blood clot despite warfarin. As you mention, there are possible side effects of the IVC filter, including unwanted movement of the filter, infection and an increased risk of blood clots in the leg.

Dear Dr. Roach: What is the difference between osteoarthritis and rheumatoid arthritis? — J.B.

Answer: Osteoarthritis is very common in older adults, and usually affects large joints like hips and knees, as well as smaller joints of the hands. It causes morning stiffness that typically lasts less than a half-hour.

Rheumatoid arthritis is less common, more frequently affects smaller joints of the hand, and causes morning stiffness that may last two hours. Rheumatoid arthritis is an autoimmune disease that can affect many more systems than the joints, and is potentially much more serious. Lab tests and X-rays can help sort out which is which.

Dr. Roach regrets that he is unable to answer individual letters, but will incorporate them in the column whenever possible. Readers may email questions to or write to P.O. Box 536475, Orlando, FL 32853-6475.