SearchMechanical Devices
An option to complement anticoagulant therapy
While mechanical prophylaxis methods have been shown to reduce the risk of deep vein thrombosis (DVT), they have been studied much less intensively than the major pharmacologic treatment options.3
Mechanical methods of prophylaxis include graduated compression stockings and various intermittent compression devices. All increase venous outflow or reduce stasis within the leg veins. Recent guidelines recommend that mechanical methods of prophylaxis should be used primarily in patients who are at high risk of bleeding, or as an adjunct to anticoagulant therapy.3
Graduated compression stockings
Graduated compression stockings (GCS) provide circumferential pressure that gradually decreases from the ankle to the thigh. This increased pressure promotes venous blood flow.111
Clinical trials on the use of GCS for DVT prevention have produced variable results.56, 112, 113 A recent study comparing fondaparinux plus GCS to fondaparinux alone for venous thromboembolism (VTE) prophylaxis after hip surgery (N=874) found that the combined treatment conferred no additional protective benefits over fondaparinux alone.114 For abdominal surgery, however, studies have shown a synergistic effect of GCS used in combination with pharmacologic prophylaxis.115
Contraindications to the use of GCS include peripheral arterial disease, severe leg oedema, peripheral neuropathy, a skin graft, and dermatitis involving the legs.111
Intermittent pneumatic compression
Intermittent pneumatic compression (IPC) uses leggings inflated by a pneumatic pump. The leggings are repeatedly inflated, and then deflated, with the goal of increasing venous return. This action mimics the natural calf muscle contractions that promote venous return in active people.111
In an analysis that combined results from 19 trials involving 2255 patients, Roderick and colleagues reported that IPC reduced the incidence of DVT by 66% compared to controls. There was no significant difference in efficacy from single-chamber as opposed to sequential compression devices.112
Venous foot pump
Venous foot pumps (VFPs) imitate the physiologic pumping action of weight-bearing on the venous plexus of the sole of the foot. In immobilised patients, this action simulates the effect of normal walking to increase venous flow from the leg.
Research on the efficacy of foot pumps is limited and inconsistent — further studies are needed to define an appropriate role for this device.56, 60, 111, 116, 117
- 3 - Geerts WH, Bergqvist D, Pineo GF, Heit JA, Samama CM, Lassen MR, and Colwell CW. Prevention of Venous Thromboembolism: American College of Chest Physicians (ACCP) Evidence-Based Clinical Practice Guidelines (8th Edition). Chest. Jun 2008: 381S–453S.
- 111 - National Collaborating Centre for Acute Care. Venous Thromboembolism: Reducing the Risk for Surgical Inpatients. London, England: Royal College of Surgeons of England; 2007:1-163.
- 56 - Motte S, Samama CM, Guay J, Barré J, Borg JY, Rosencher N. Prevention of postoperative venous thromboembolism. Risk assessment and methods of prophylaxis. Can J Anaesth. 2006;53(6 suppl):S68-S79.
- 112 - Roderick P, Ferris G, Wilson K, et al. Towards evidence-based guidelines for the prevention of venous thromboembolism: systematic reviews of mechanical methods, oral anticoagulation, dextran and regional anaesthesia as thromboprophylaxis. Health Technol Assess. 2005;9(49). :iii-iv, ix-x, 1-78.
- 113 - Schulz SL, Stechemesser B, Seeberger U, Meyer D, Kesselring C. Graduated compression stockings for the prevention of venous thromboembolism in surgical patients in the age of low molecular weight heparins. J Thromb Haemost. 2005;3(10):2363-2365.
- 114 - Cohen AT, Skinner JA, Warwick D, Brenkel I. The use of graduated compression stockings in association with fondaparinux in surgery of the hip. A multicentre, multinational, randomised, open-label, parallel-group comparative study. J Bone Joint Surg Br. 2007;89(7):887-892.
- 115 - Agnelli G. Prevention of venous thromboembolism in surgical patients. Circulation. 2004;110(24 suppl 1):IV4-IV12.
- 60 - Nicolaides AN, Fareed J, Kakkar AK, et al. Prevention and treatment of venous thromboembolism. International Consensus Statement (guidelines according to scientific evidence). Int Angiol. 2006;25(2):101-161.
- 116 - Wilson NV, Das SK, Kakkar VV, et al. Thrombo-embolic prophylaxis in total knee replacement. Evaluation of the A-V Impulse System. J Bone Joint Surg Br. 1992;74(1):50-52.
- 117 - Warwick D, Harrison J, Whitehouse S, Mitchelmore A, Thornton M. A randomised comparison of a foot pump and low-molecular-weight heparin in the prevention of deep-vein thrombosis after total knee replacement. J Bone Joint Surg Br. 2002;84(3):344-350.
- Prophylaxis
- The prevention of a disease or pathological condition.
- Fondaparinux
- An indirect Factor Xa inhibitor comprising a synthetic pentasaccharide sequence matching the part of the heparin molecule that binds to antithrombin. It is administered by subcutaneous injection.
- Venous thromboembolism
- A condition in which a blood clot (thrombus) forms in a vein, which in some cases then breaks free and enters the circulation as an embolus, finally lodging in and completely obstructing a blood vessel, e.g., in lungs causing a PE. The term encompasses both DVT and PE.
- Oedema
- The presence of abnormally large amounts of fluid in the intercellular tissue spaces of the body, usually used to describe demonstrable accumulation of excessive fluid in subcutaneous tissues.
- Intermittent pneumatic compression
- A mechanical method of preventing DVT in the legs. IPC machines use air bladders that are wrapped around the thigh and/or calf. These alternately inflate and deflate, squeezing the muscles and increasing blood flow.
