A deep-vein thrombosis, or DVT, is an abnormal blood clot that blocks blood flow in a large vein. DVTs in the arm cause pain, swelling, discoloration and occasionally weakness. Clot fragments can break off and travel to the lungs, causing pulmonary emboli in up to 1/3 of cases. Persistent arm swelling and discomfort as well as recurrent clots are possible long-term complications. Treatment is aimed at restoring blood flow through the blocked vein and preventing pulmonary emboli and recurrent clots.
Anticoagulation
Most patients with upper-extremity DVTs are treated with anticoagulants, which are drugs that thin the blood and prevent clots from forming. Anticoagulants prevent the clot from growing larger, and reduce the risk of pulmonary emboli. Heparin is given for five to seven days, followed by a longer course of warfarin. Heparin is a rapidly acting blood thinner that inactivates several key clotting factors, which are the proteins in blood that cause it to clot. Newer forms of heparin have a longer lasting anticoagulant effect and are given as an injection under the skin. Warfarin blocks the ability of vitamin K to activate several clotting factors and is given as a daily pill. Since it usually requires between five and seven days of treatment for warfarin to become effective, initial treatment with heparin is necessary. Warfarin is continued for at least three months. By preventing clot growth or recurrence, anticoagulants help the body's fibrinolytic system, which normally breaks down clots.
Thrombolytics
Thrombolytic drugs are the "clot busters" that activate the fibrinolytic proteins in blood to dissolve clots. They are infused through a tube called a catheter in the vein directly into the clot. Thrombolytics are most likely to dissolve the clot if they are given during the first few weeks after symptoms develop. They are more effective in restoring normal blood flow through the blocked vein than blood thinners but have a higher risk of bleeding complications.
Surgery
Several more invasive techniques are used occasionally to remove the clot and improve blood flow. Large clots can be broken up and removed through a catheter inserted into the arm vein. Angioplasty involves inserting a device with a balloon through a catheter in the clotted vein. The balloon is inflated and deflated to break up the clot. In rare cases, a special tube called a stent is placed to keep the vein open if there is persistent narrowing after the clot is removed. Some people develop clots because the large vein draining blood from the arm is compressed in the narrow space between the first rib and the collarbone in the upper chest, especially during strenuous exercise. Surgical removal of the first rib and scar tissue compressing the vein improves blood flow and prevents recurrent clots from forming.
Filters
A filter is a device that blocks the migration of clots from the arm to the lungs where they cause pulmonary emboli. The filter is inserted through a vein in the groin or in the neck and positioned in the superior vena cava, which is the large vein bringing blood from the arm back to the heart. Filters are used in rare patients with upper-extremity DVTs who cannot receive blood thinners because of a high risk of bleeding. They are also used when anticoagulation does not prevent clot progression or pulmonary emboli. Modern filters are potentially removable if they are in place for only a short period of time.
Combinations
Several treatment strategies are often combined to achieve the best long-term results. For example, thrombolytic drugs are given initially to dissolve the clot, followed by a subsequent course of warfarin to prevent recurrent clots. Thrombolytics may be coupled with surgical removal of a first rib compressing the vein, or with catheter disruption and removal of particularly large clots. Since filters do not prevent recurrent clots or long-term symptoms, blood thinners are restarted after filter placement whenever possible. Treatment plans are individualized based on the underlying cause of the clot, coexisting health problems, lifestyle and the availability of expertise with newer techniques.
References
- "Chest"; Antithrombotic Therapy for Venous Thromboembolic Disease: American College of Chest Physicians Evidence-Based Clinical Practice Guidlines (8th Edition); Clive Kearson, Susan R. Kahn, Giancario Agnelli, Samuel Goldhaber, Gary E. Raskob and Anthony J. Comerota; Volume 133 Supplement pg 454S-545S; June 2008
- "Thrombosis Research"; Treatment of Subclavian-Axillary Vein Thrombosis: Long-Term Outcome of Anticoagulation Verses Systemic Thrombolysis; Schila Sabeti, Martin Schillinger, Wolfgang Mlekusch, Markus Haumer, Ramaznali Ahmadi and Erich Minar; Volume 108 279-pg 285; 2003
- "Acta Haematologica"; Upper Limb Deep Vein Thrombosis: A Literature Review to Streamline the Protocol for Management; Muhammand S. Sajid, Naeem Ahmed, Mittal Desai, Daryll Baker and George Hamilton; Volume 118 pg 10-18; 2007
- "Radiology"; Acute Upper Extremity Deep Venous Thrombosis: Safety and Effectiveness of Superior Vena Caval Filters; Liam D. Spence, Michael G. Gironta, Hitten M. Malde, Charles T. Mickolick, Michael A. Geisinger and Bart L. Dolmatch; Volume 210 pg 53-58; January 1999
