OA

©2008 OA • 33 Sewall Street • Portland, ME 04102 • (207) 828-2100

Guide to Blood Clots and Hip Replacement Surgery (Deep Venous Thrombosis (DVT) with Joint Replacement Surgery)

Blood Clots

Arteries are blood vessels that carry blood away from the heart to body tissues and organs. Veins are blood vessels through which blood travels from all parts of the body back to the heart.

A blood clot is a jelly-like mass of thickened blood. The body normally forms a blood clot to stop bleeding. After hip surgery there will be a blood clot near the new hip joint. This is normal, and not dangerous.

If a blood clot develops inside a vein, however, it can block the normal flow of blood and cause temporary and long-term problems. This can result in pain, tenderness and swelling of the leg. When a blood clot occurs in one of the main veins of the body (usually a leg or pelvic vein after hip surgery) it is called a deep vein thrombosis or DVT. These clots become life threatening if they move to the heart, lungs or brain. If a clot breaks loose from a vein, it may travel through the heart and can block lung arteries. This is called a pulmonary embolism or PE. A PE can cause sharp chest pain, shortness of breath, coughing up blood or passing out. If the clot is severe enough, it can be life threatening or fatal.

Methods to prevent blood clot after surgery may include early mobilization and activity, elevation of the feet, ankle exercises, elastic stockings, compression devices that passively help blood flow in the legs, and anti-coagulation medicines.

PREVENTION OF DEEP VEIN THROMBOSIS (DVT PROPHYLAXIS)

What Are The Issues?

The medical term for a blood clot in the blood vessel is a thrombus. Deep vein thrombosis (DVT) is a formation of a blood clot in one of the deep veins of the body, particularly in the leg or pelvis. It is a problem that can be asymptomatic (silent), or in the worse case scenario, fatal. Death can occur if a blood clot which forms in the deep veins of the body breaks off and travels to the lungs, heart or brain and causes severe overload of the capacity to breath or pump blood. Some doctors think that even a silent blood clot can cause chronic swelling or skin ulcerations, a difficulty called post-phlebitic syndrome.

The risk of DVT is increased in a number of circumstances. Lower extremity surgery, and specifically total hip replacement surgery, increases the risk of deep vein thrombosis. The surgery heightens the body's tendency for coagulation or clotting. In addition, when the leg is manipulated during surgery there may be irritation to the walls of the major blood vessels in the leg. Finally, during and after surgery the lower extremity is not used as much and, therefore, the normal blood flow rate is decreased. The leg muscles usually help venous blood return to the heart when they are used.

Further factors heighten the risk of blood clotting. These include history of previous DVT or PE, cancer, obesity, and conditions that predispose to abnormal clotting (for example, a family history of DVT/PE or known medical condition associated with increased clotting).

Patients contemplating hip replacement surgery therefore need to understand the issues regarding what methods should be used to minimize the chance of deep vein thrombosis.