Deep venous thrombosis (DVT) (or thrombophlebitis) is the medical name to describe blood clots formed in the veins of the legs. This is a common problem following many types of surgical procedures. These blood clots form in the large veins of the calf. They may continue to grow and extend up into the veins of the thigh, and in some cases into the veins of the pelvis.
It is true that some people develop DVT even though they have not undergone any recent surgery. But the risk is much higher following surgery-especially surgery involving the pelvis or the lower extremities. There are logical reasons why the risk is increased. The body is trying to stop bleeding associated with surgery, so the body's clotting mechanism becomes very active during this period. Also injury to blood vessels around the surgical site from normal tugging and pulling during surgery can set off the clotting process. Blood that does not move well sits in the veins and becomes stagnant. If it sits too long in one spot it may begin to clot.
The prevention of DVT is a serious matter. Blood clots that fill the deep veins of the legs stop the normal flow of venous blood from the legs back to the heart. This causes swelling and pain in the affected leg. If the blood clot inside the vein does not dissolve, the swelling may become chronic and can cause permanent discomfort. While the discomfort is unpleasant, the blot clot actually poses much more serious danger. If a portion of the forming blood clot breaks free inside the veins of the leg, it may travel through the veins to the lung. There it can lodge itself in the tiny vessels of the lung, cutting off the blood supply to the blocked portion of the lung. This blocked portion cannot survive and may collapse. This is called a pulmonary embolism. If a pulmonary embolism is large enough, and the portion of the lung that collapses is large enough, it can cause death.
Reducing the risk of developing DVT is a high priority following any type of surgery. Preventative measures fall into two categories, mechanical involves getting the blood moving better, and medical involves using drugs to slow the clotting process.
Mechanical
Blood that is moving is less likely to clot. Getting you moving so that your blood is circulating is perhaps the most effective treatment against developing DVT. Once you begin walking, your leg muscles will contract and keep the blood in the veins of the legs moving. But you can still do things while you are in bed to increase the circulation of blood from the legs back to the heart. Simply pumping your feet up and down (like pushing on the gas pedal) contracts the muscles of the calf, squeezes the veins in the calf, and pushes the blood back to the heart. You should do these exercises as often as you can.
Pulsatile stockings are very effective. They are special stockings that wrap around each calf and thigh. A pump inflates them every few minutes, squeezing the veins in the legs and pushing blood back to the heart. Support hose, sometimes called TED hose, are still commonly used following surgery. The hose work by squeezing the veins of the leg shut. This reduces the amount of stagnant blood that is pooling in the veins of the leg and lowers the risk of blood clotting.
Medical
Medications that slow down the body's clotting mechanism can reduce the risk of DVT. They are widely used following surgery of the hip and knee. Aspirin can be used in very low risk situations. Heparin shots may be given twice a day in moderately risky situations. When there is a high risk for developing DVT, several potent drugs are available that can slow the clotting mechanism very effectively. Heparin can be given by intravenous injection, a new drug called Lovenox can be given in shots administered twice a day, and Coumadin can be given by mouth. Coumadin is the drug of choice when the clotting mechanism must be slowed for more than a few days because it can be taken orally.
In most cases of spinal surgery, both mechanical and medical measures are used
simultaneously. It has become normal practice to use pulsatile stockings and
place patients on some type of medication to slow the blood clotting mechanism.
You are encouraged to get out of bed as soon as possible and begin exercises
immediately after surgery.
