Washington, DC -- Blood clots are a leading cause of disability and death in patients following surgery, despite medical advances in their prevention, diagnosis, and treatment. The American College of Obstetricians and Gynecologists (ACOG) today issued updated evidence-based treatment recommendations to help reduce the incidence of this frequent, but often preventable, cause of death in gynecologic surgery patients. The recommendations detail the risk factors for developing blood clots among surgery patients as well as the treatments to help prevent them.
According to ACOG, each year 2 million Americans are diagnosed with deep vein thrombosis (DVT) and nearly a third of them develop a pulmonary embolism (PE), resulting in 60,000 deaths a year. Blood clots that develop in the veins located deep in the muscles of legs, thighs, and pelvis are called DVT. When a piece of a DVT breaks free, travels to the heart, and is pumped into the arteries of the lung, this is called a PE. Pulmonary emboli can be fatal if they are large and block one or both of the major arteries that send blood to the lungs.
"Women should be aware of this rare, but serious, complication of surgery and should discuss preventative treatment options with their surgeon," says Daniel Clarke-Pearson, MD, who headed the work group that developed the revised treatment recommendations. "Physicians should evaluate every patient prior to surgery to determine her risk level of developing DVT or PE and prescribe the appropriate preventive measures."
Blood clots can also result in lifelong chronic problems, including postthrombotic syndrome, venous insufficiency, and pulmonary hypertension. DVTs can result in long-lasting swelling, pain, pigmentation, and scaling of the affected leg. Some patients who develop PE can suffer with heart function problems that may require ongoing medication and possibly surgery.
"Some of the many known risk factors for blood clots include surgery, confinement to bed, prolonged sitting, cancer, increasing age, pregnancy and the postpartum period, hormone therapy, oral contraception, obesity, smoking, varicose veins, inflammatory bowel disease, and certain acquired or inherited blood disorders (such as Factor V Leiden)," said Dr. Clarke-Pearson. Risk categories have recently been refined, and surgery patients are now classified as low-, moderate-, high-, or highest-risk according to their age, surgery type (minor or major), and personal risk factors.
Compression devices and medication are the two types of treatments to prevent blood clots in patients undergoing surgery. There are two types of compression devices: graduated compression stockings (GCS) and intermittent pneumatic compression devices (IPC). Both fit over the legs and help prevent pooling of blood in the calves. Anticoagulant medication that thins the blood includes two forms of the drug heparin. For patients at highest risk of developing clots, a combined approach of medication and a compression method may be appropriate. Getting patients out of bed and walking as soon as possible after surgery also helps prevent blood clots.
"A significant number of lives can be saved by providing relatively simple and safe preventive treatments," according to Dr. Clarke-Pearson. "Methods to prevent DVT and PE are well established after years of clinical trials."
ACOG emphasizes the importance of taking complete medication histories from patients prior to surgery, including their use of nonprescription medications and supplements. An estimated 38 million Americans use herbs or complementary and alternative medicines each year, some of which can interfere with prescription drugs. A number of herbs, in addition to nonsteroidal anti-inflammatory drugs (NSAIDs), can cause excessive bleeding if they are taken by patients who are also taking anticoagulants. Other herbs can reduce the effectiveness of anti-coagulants. ACOG's document lists common herbs and supplements that may interfere with anticoagulant therapy, including cranberry and grapefruit juice, Dong quai, garlic, gingko, glucosamine-chondroitin, green tea, melatonin, grapefruit, and St. John's wort. Patients are advised to avoid all herbs and drugs known to interact with oral or injected anticoagulants.
Practice Bulletin #84, "Prevention of Deep Vein Thrombosis and Pulmonary Embolism," is published in the August 2007 issue of Obstetrics & Gynecology.