vena cava filter

Vena Cava Filter 

Definition

A vena cava filter is a device inserted into a major vein to prevent a blood clot from entering the lungs.

Purpose

The purpose of a vena cava filter is to prevent a blood clot from potentially traveling to the lungs. A thrombus clot traveling to the lungs is called a pulmonary embolism (PE). A thrombus in the deep venous system (the part of the circulation that brings blood back to the heart) represents a disorder of normal hemostasis (the normal clotting of blood).

Insertion of a vena cava filter is indicated for patients who:

• cannot receive medications that can dissolve the clot (anticoagulation therapy)
• have a thrombus in a deeply situated vein
• experiance complication of anticoagulation therapy such as bleeding
• experiance failure of anticoagulation therapy to prevent pulmonary embolism
• have an embolus in the lungs (pulmonary embolectomy) removed
• have a recurrent embolism while receiving adequate medications
• have significant bleeding complications during anticoagulation

Precautions

There are no significant precautions concerning insertion of a vena cava filter. The devices are usually effective and short-term complications are unusual

Description

Vena cava filters are usually inserted in to prevent PE caused by a thrombosis in a deep vein (DVT). Approximately 60% of patients who die in a hospital have evidence of PE during autopsy. The incidence (number of new cases) of DVT is highest for patients undergoing surgical repair of a fractured hip. However, DVT is common in both surgical and medical patients. DVT is found in 29-33% of patients in medical intensive care units (MICU) and in 27-40% of patients with a heart attack (myocardial infarction). Vena cava filters are placed to prevent thrombi from entering the lungs. There is currently a new type of filter called the Kim-Ray-Greenfield filter.

Preparation

Insertion of a vena cava filter is an invasive procedure. The patient is prepared for this procedure using standard surgical protocols. The VCF is commonly implanted in the jugular vein in the neck or the femoral vein in the groin. The procedure is generally well tolerated.

Aftercare

This depends on the patient's health status and recommendation's for continued care.

Risks

Many patients have died from PE even with a vena cava implantation. Use of a VCF is primarily indicated if there are contraindications for anticoagulation therapy. VCF can increase a patient's susceptibility for developing recurrent DVT.

Normal results

Patient progresses well and prevention of large emboli that can cause a PE is successful.

Abnormal results

The desired effect is not accomplished and the patient develops a PE resulting in death.

Key terms

Embolus — An embolus (or emboli the plural form) is a blood clot that has detached from its site of origin and travels to the lungs (pulmonary artery), where it can rupture the artery, causing death.

Pulmonary embolism — A traveling thrombus that has lodged in the pulmonary artery.

Thrombus — A thrombus (or thrombi the plural form) is a blood clot that can form in a deeply situated vein.

Resources

Books

Bone, Roger C. Pulmonary & Critical Care Medicine. Mosby-Year Book, Inc., 2000.

Braunwald, Eugene, et al, editors. Heart Disease: A Textbook of Cardiovascular Medicine. 6th ed. W. B. Saunders Company, 2001.

Goldman, Lee, et al, editors. Cecil Textbook of Medicine. 21st ed. W. B. Saunders Company, 2000.

Rakel, Robert E., et al, editors. Conn's Current Therapy. 53rd ed. W. B. Saunders Company, 2001.

Townsend, Courtney M. Sabiston Textbook of Surgery. 16th ed. W. B. Saunders Company, 2001.

Periodicals

Isnard, R., and M. Komajda. "Thromboembolism in Heart Failure, Old Ideas and New Challenges." European Journal of Heart Failure June 2001.

Organizations

American College of Angiology. 295 Northern Blvd., Ste. 104 Great Neck, NY 11021-4701.

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vena cava filter

Cardiovascular disease A device implanted within veins, usually leg veins, that are at high risk of developing DVT and thromboembolism. See Deep vein thrombosis, Greenfield filter, Pulmonary thromboemboloism.