Deep Vein Thrombosis After Surgery

Surgery increases your risk of developing dangerous blood clots in your veins, a condition that requires immediate attention and careful prevention to protect your health and recovery.

Table of contents

• What Is Postoperative Deep Vein Thrombosis?
• Why Surgery Increases Your Risk
• Who Is at Higher Risk After Surgery?
• Warning Signs to Watch For
• How to Prevent Blood Clots After Surgery
• Treatment Approaches
• Long-Term Complications
• Life After a Blood Clot

What Is Postoperative Deep Vein Thrombosis?

Deep vein thrombosis (DVT) is a serious condition where a blood clot forms in a vein deep inside your body, most commonly in your leg^[1]. When this happens as a result of hospitalization, surgery, or another medical procedure, doctors call it healthcare-associated venous thromboembolism^[8].

The clot can partially or completely block blood flow through your vein. While DVT itself may not immediately threaten your life, the real danger comes when a piece of the clot breaks free and travels through your bloodstream to your lungs^[1]. This condition, called a pulmonary embolism (PE), blocks blood flow in your lungs and can be fatal^[5].

Doctors use the term venous thromboembolism (VTE) to describe both DVT and PE together, because these two conditions are closely related and their prevention and treatment are similar^[5].

Why Surgery Increases Your Risk

Surgery is one of the major causes of deep vein thrombosis^[2]. More than half of all DVTs happen as a result of being in the hospital from a medical illness or following surgery^[3]. In fact, more than a third of blood clots diagnosed each year are directly related to a recent hospitalization^[8].

Several factors related to surgery raise your risk for blood clots. When you stay in bed for long periods during recovery, blood flows more slowly in your deep veins, which can lead to clot formation^[2]. You’re most likely to develop a clot between 2 and 10 days after surgery, but your risk remains high for about 3 months^[2]. Studies have found that 40% of blood clots occur while patients are still in the hospital, while 60% develop up to 90 days after leaving the hospital^[8].

The surgery itself can also cause blood clots. Long procedures where you lie on the operating table for many hours allow your blood to settle and pool, making it easier to clot^[2]. During an operation, tissue, debris, fat, or other substances can get released into your blood, making it thicker around those particles. Blood vessels can also be damaged during surgery, which triggers clotting^[2].

While DVT can develop after any major surgery, you’re especially at risk if you’ve had major operations on your abdomen, pelvis, hips, or legs^[2]. Specific high-risk procedures include knee or hip replacement, peripheral and coronary artery bypass, surgery to remove cancer, brain surgery, and other major operations^[2].

Who Is at Higher Risk After Surgery?

While surgery increases everyone’s risk for blood clots, certain factors make you even more vulnerable. You may have a greater chance of DVT after surgery if you smoke, have had DVT in the past, are overweight or obese, or have close family members with DVT^[2].

Other risk factors include being pregnant, having disorders that affect your blood or veins, being older (especially over age 55 or 60), using certain medicines including birth control pills and hormone therapy, or having specific types of cancer^[2][8].

Several factors during and after your hospital stay can also increase your risk. These include how extensive or long your procedure was, how you had to be positioned during surgery, the type of anesthesia used, injury to a vein during surgery, fractures, severe muscle injury, being confined to bed, and limited movement such as wearing a cast^[2][8].

Warning Signs to Watch For

Up to 30% of people with DVT don’t have symptoms, or the symptoms may be very mild^[3]. However, it’s important to know the warning signs so you can get help quickly if they appear.

Symptoms of DVT in your leg include pain in your calf and leg that’s unrelated to your surgical incision, tenderness or redness about or below your knee, swelling of your thigh, calf, ankle, or foot, pain or tenderness in your leg or arm (which may only happen when standing or walking), warm skin around the painful area, and red or darkened skin^[1][3].

The warning signs of pulmonary embolism are even more serious and require immediate emergency care. These include sudden shortness of breath, chest pain (particularly with breathing), and coughing up blood^[1]. If you develop any of these signs after surgery, notify your doctor immediately or call emergency services^[1].

How to Prevent Blood Clots After Surgery

As many as 70% of cases of healthcare-associated blood clots could be prevented through proper prevention measures^[8]. Your doctor will outline a program to help prevent blood clots after your surgery, which may include several different approaches^[1].

Blood-thinning medications, also called anticoagulants, help prevent blood clots from getting bigger and reduce the risk of developing more clots^[2]. These medicines make it harder for your blood cells to stick together and form clots. You may take them by mouth, injection, or through an IV. Anticoagulant medication typically begins prior to surgery, and you’ll usually continue the treatment after you leave the hospital and begin home recovery^[6].

Compression stockings are special tight-fitting socks that keep a certain amount of pressure on your leg, which helps with blood flow^[2]. Your doctor might recommend gentle pressure to keep blood from pooling and clotting, such as wearing a sleeve or boot that periodically fills with air or wearing compression stockings^[20].

Movement and exercise are crucial for preventing blood clots. Helping your blood circulate makes it harder for clots to form^[20]. Your doctor may tell you to move around as soon as possible after surgery and as you heal. If you cannot get up and walk, try to flex and stretch your feet to improve blood flow in your calves^[20]. Post-surgery exercises may include a graduated walking program, seated leg lifts, ankle turns, and stretching^[6].

Your doctor may also recommend periodic elevation of your legs and lower leg exercises to increase circulation^[1]. It’s important to follow your doctor’s instructions carefully to minimize the risk for blood clots during the first several weeks of recovery from surgery^[1].

Treatment Approaches

If you develop DVT after surgery, the primary goals of treatment are to prevent the clot from getting bigger, prevent it from breaking loose and traveling to your lungs, and reduce the chances of another DVT^[12].

The mainstay of treatment is anticoagulation with blood-thinning medicines^[11]. These include heparin (given as a shot), direct oral anticoagulants (DOACs), and warfarin (taken by mouth)^[20]. You may need to take these medicines for several months^[3].

In some cases when the clot is very large or medication alone cannot restore healthy circulation, surgery may be needed^[15]. A procedure called thrombectomy involves removing the clot, either by making an incision in the vein or by inserting a thin tube called a catheter through blood vessels to reach the clot^[15].

Another less invasive option is catheter-directed thrombolysis, which dissolves the clot rather than removing it. The doctor inserts a catheter into a vein and injects special dissolving medications guided by X-ray equipment^[15].

In certain situations, your doctor may recommend placing a filter in your inferior vena cava (the large vein that carries blood from your lower body back to your heart) to prevent clots from reaching your lungs^[12].

Long-Term Complications

Even after successful treatment of DVT, you may experience long-term effects. As many as half of those who get a DVT in their legs develop symptoms of post-thrombotic syndrome, which includes intermittent leg pain and swelling that may last months to years^[3].

This syndrome happens because of damage to the valves and inner lining of your veins, leading to blood pooling more than it should. This increases the pressure inside your veins and causes pain and swelling^[3]. Symptoms occur in the same leg that had the DVT and can include a feeling of heaviness, itching, tingling or cramping, leg pain that’s worse with standing and better after resting or raising your leg, widening of leg veins, swelling, and darkening or redness of the skin^[7].

Factors that may increase your risk for post-thrombotic syndrome include being very overweight, having a DVT that causes symptoms, getting a clot above the knee instead of below it, having more than one DVT, and not taking blood thinners after your DVT^[7].

Life After a Blood Clot

If you’ve had a blood clot after surgery, your risk for another one increases^[18]. After the initial recovery period, it’s important to make lifestyle changes that can help prevent future blood clots.

Stay as active as possible. One of the risk factors for DVT is inactivity, so moving more may lower your risk for future clots^[19]. Studies show that regular exercise lowers your risk for venous thromboembolism. Exercises like walking or swimming can help you heal and boost your blood flow^[18].

Try not to stay seated for more than 2 hours at a time—get up and walk around regularly^[18]. If you’re traveling for 3 hours or more by plane, train, or car, take breaks often to stretch your legs, walk around when possible, or do exercises from your seat^[9].

Reach or maintain a healthy weight, as higher body weight dramatically increases your risk for blood clots^[16]. If you smoke, quit—smoking can increase your risk for future clots by affecting the quality of your platelets^[16]. Drink plenty of water to stay hydrated, as dehydration can slow your blood circulation^[16].

Practice stress management through activities like spending time in nature, meditating, or practicing yoga. Stress and inflammation go hand in hand, and inflammation can raise your blood pressure levels and increase your risk for future clots^[16].

Continue to follow up with your doctor regularly for vascular health check-ins. Let all your doctors know if you’ve had a blood clot of any kind, and if you take blood thinners, inform your dentist when making appointments^[18]. Be watchful for signs of another clot, such as new or worse pain, pressure, or cramping in your calf, or shortness of breath and chest pain^[18].