Lower extremity deep vein thrombosis and pulmonary embolism
Venous thrombosis occurs when a blood clot develops in a vein. The clots attach to the walls of the veins and can cause pain and redness (inflammation) in the surrounding area, called “thrombophlebitis”.
A clot in a deep vein, known as a deep vein thrombosis (DVT), is a type of thrombophlebitis. The clot can cause a total or partial blockage of a deep vein.
A pulmonary embolism is formed when part or all of the embolus in a DVT comes off and is transported with the blood vessels to the heart, where it can be pumped into the pulmonary circulation, thereby blocking pulmonary artery blood flow. This prevents blood from flowing to the lungs and other parts of the body.
Deep vein thrombosis and pulmonary embolism is a serious condition. It can affect people of any age and race. Fortunately, DVT and pulmonary embolism are largely preventable. Advances in medicine have improved the diagnosis and treatment of this condition.
How do veins work?
The body has 2 sets of blood vessels: arteries and veins. The left side of the heart is used to carry oxygen-rich blood throughout the body via the arteries. The veins carry the less oxygenated blood from the body back to the right side of the heart and pump it into the pulmonary circulation for another oxygen exchange. The oxygen-rich blood then crosses to the left side of the heart to begin a new cycle again.
There are three types of veins in the body, superficial veins are located immediately under the skin. The deep veins are located in the middle of the muscles of the extremities and carry most of the blood back to the heart. The deep veins in the lower extremities include the iliac vein, femoral vein, and N vein. The traffic veins carry blood from the superficial veins to the deep veins.
The veins of both the upper and lower extremities have valves that open as blood flows to the heart and then close to prevent blood from returning to the foot or hands. The muscles of the lower extremities promote the return of blood to the heart.
When the walls of the veins become weak, or the valves function abnormally, blood flow problems will occur. A decrease in the rate of blood flow in the veins will lead to edema and thrombosis.
Thrombophlebitis
There are two forms of thrombophlebitis – superficial venous thrombophlebitis and deep vein thrombosis (DVT)
Superficial venous thrombophlebitis
Superficial venous thrombophlebitis occurs in the superficial veins of the skin (superficial veins). When a superficial vein is affected, the surface of the skin becomes red, hardened, painful or lumpy. This condition can often be detected in time and improved quickly without serious complications. The clot is not usually transported to other parts of the body.
Some patients with superficial vein thrombophlebitis also have deep vein thrombosis. Therefore, if you develop symptoms of superficial vein thrombosis, you should seek medical attention.
Deep vein thrombosis
Deep vein thrombosis occurs when a blood clot develops in a deep vein. Deep vein thrombosis is a serious condition. The clot can partially or completely block blood flow through the vein. Some or all of the DVT can be transported through the veins to the heart, leading to serious complications, including pulmonary embolism.
Risk factors for DVT or pulmonary embolism
You carry risk factors for DVT or pulmonary embolism if you
1. are treated with oral contraceptives or sex hormones
2. have cancer.
3. have a trauma or surgery that causes restriction of activity.
4. having one of the immune system disorders.
5, having an inherited or acquired coagulation abnormality.
6. have a history of venous injury such as an intravenous catheter, central venous placement or pacemaker that would result in a slowing of blood flow
7, prolonged inactivity in a car or airplane cabin (inactivity will result in slower blood flow).
8. prolonged bed rest due to illness or medical problems (such as surgery, stroke, heart attack or hip and lower extremity fractures)
9, paralysis of limbs due to stroke.
10, overweight.
11, Pregnancy or childbirth will increase the pressure in the pelvic and lower extremity veins.
Deep Vein Thrombosis
Symptoms of DVT
A typical DVT of the upper or lower extremity will present with.
pressure or pain, edema, increased skin temperature, and a reddish-purple color.
Since DVT is a potentially fatal disease, you need to see a doctor as soon as these symptoms occur!
How to diagnose DVT
If your doctor thinks you have DVT, he/she will ask you about your risk factors for DVT and perform a physical examination. He/she may prescribe the following tests.
Color ultrasound of the veins of the lower extremities
Color ultrasound of the veins of the lower extremities is the most commonly used technique to diagnose DVT and can be used to show veins and blood flow.
In this test, an operating rod (ultrasound probe) is placed on your test limb that sends ultrasound waves into your tissues and receives their echoes. The computer receives the echo signal and converts it into a moving image that is displayed on a fluorescent screen. Blood clots can be shown in the images. Color ultrasound of the lower extremity veins is a painless and non-invasive procedure.
Venography
During a venogram, contrast is injected into a large vein in your foot or elbow. X-rays are used to visualize the veins in the lower extremities and feet, which will reveal blood clots.
This is an invasive test and is performed by a hospital radiologist.
Blood tests
The vast majority of patients with DVT have elevated blood levels of D-dimer, a fibrin degradation product in the blood. However, elevated D-dimers are also seen in other clinical conditions. Blood tests for D-dimer are often performed in conjunction with other tests in the diagnosis of DVT.
Genetic Testing
If you have a family history of blood clots and need to rule out the possibility of inherited thrombophilia, genetic testing will be performed. You will need to proactively report this to your doctor so that he/she can arrange the appropriate tests.
Treatment of DVT
Treatment for DVT includes.
Elevation of the affected limb; compression; anticoagulant medications to stop further clot formation (heparin given intravenously or subcutaneously, or orally such as Warfarin); more aggressive treatment with catheters to inject thrombolytic drugs (thrombolytic enzymes) into the clot to melt the clot locally or balloon angioplasty; sometimes combination therapy gives the best results. Treatment may last for a period of time or may be required for life.
The type of treatment depends on many factors, including the site of the embolus, its size, and your medical history. The right option for you will need to be discussed with your doctor.
It is important to follow up consistently after treatment, including setting your follow-up schedule, and recommending long-term follow-up as recommended by your doctor.
Compression
Your doctor may recommend that you purchase compression compression stockings. These special socks tightly encase the leg, thus preventing edema and reducing complications of DVT, such as post-phlebitis syndrome.
Anticoagulation
You may need anticoagulant medication (blood thinning) to prevent further thrombosis. The most common anticoagulants are warfarin and heparin.
The vast majority of patients with DVT need to be treated with annotated low molecular weight heparin. This treatment can be done on an outpatient basis. In rare cases, patients need to be hospitalized for intravenous administration of low-molecular-weight heparin or heparin.
Warfarin is an oral tablet. Your doctor may give you warfarin for several months or even longer to treat and follow up DVT.
Thrombus removal or collateral creation
Direct catheter thrombolysis involves injecting the thrombolytic drug directly into the thrombus localized through a thin plastic catheter. The catheter is inserted into the vessel from a lower extremity vein.
Thrombectomy can be performed by cutting open the vessel where the thrombosis occurs with a fine drill. Thrombectomy can also be accomplished through a catheter inserted into a lower extremity vein.
Sometimes, balloon angioplasty is used to dilate a vessel that has already been recanalized. A mesh catheter (stent) inserted into the vein can be used to open the vein.
These 3 methods are performed only when needed. In rare cases, surgical retrieval is required to recanalize a deep vein that is blocked by a thrombus.
Pulmonary embolism
DVT can cause serious problems. The most common is pulmonary embolism.
If part or all of the DVT is dislodged, it may fall through the venous system and into the right heart (Figure 6). Once present, it may be pumped with blood flow into the pulmonary vessels thereby blocking the pulmonary arteries (i.e., pulmonary embolism). This will block some of the blood flow to the lungs. There are life-threatening conditions that require hospitalization.
Symptoms of a pulmonary embolism
Chest pain, difficulty or painful breathing, coughing (which may lead to bloody sputum), increased heart rate, dizziness, purple skin, cold and clammy extremities, sweating or fever, and in rare cases, loss of consciousness or sudden death.
Diagnosis of pulmonary embolism
The diagnosis of pulmonary embolism can be difficult, especially if the patient has underlying cardiopulmonary problems. Your doctor may give you one or more of the following tests to discover the cause of your symptoms
CT scan
CT is the most commonly used diagnostic tool for pulmonary embolism. CT scans are almost as sensitive as pulmonary angiograms for detecting pulmonary embolism.
CT scans allow your doctor to detect abnormalities in your body in 2 dimensions with a very thin “slice” of your body.
Pulmonary Perfusion Imaging
Also known as ventilation/perfusion (VQ) imaging, this is a test that uses a radioactive tracer to study airflow (ventilation) and blood flow (perfusion) in the lungs.
You will inhale a fine radioactive tracer and another radioactive tracer will be injected into the vein. These small particles of radiotracer do not cause any side effects or complications.
This test often takes about 1 hour.
Pulmonary angiography
In this procedure, a catheter is inserted from a large vein (often from the groin) through the heart into the pulmonary artery. A special contrast agent is injected into the catheter and an x-ray scan is performed following the distribution of the contrast agent in the pulmonary artery.
This test often takes an hour, but you will need to be in bed for several more hours after the test. This test is the most accurate way to diagnose a pulmonary embolism.
Chest X-Ray
This is a non-invasive test that shows your heart and lungs. A chest x-ray cannot diagnose a pulmonary embolism, but it can rule out other conditions with similar symptoms.
Rapid diagnosis and treatment of pulmonary embolism is important because about 30% of people with pulmonary embolism die without treatment. However, patients with pulmonary embolism who are diagnosed and treated promptly have a good prognosis.
Treatment of pulmonary embolism
Anticoagulant (blood-thinning) medications can keep the clot from getting any larger. Medications can also prevent new clots from forming.
Other medications (thrombolytic drugs) can be used to dissolve the clot.
Rarely, surgical removal of the clot is required.
Other complications of DVT
Other serious complications of DVT include valve damage in the affected vein (venous stasis), sudden cardiac death, or stroke.
Venous stasis
DVT may damage the affected valves, especially the deep veins of the lower extremities. The valves usually prevent blood from flowing backwards during standing. When the valves function abnormally, the following conditions can occur.
Varicose veins. Stagnation of blood will cause the veins to form a bulbous dilatation, resulting in varicose veins.
Edema of the lower extremities
Skin pigmentation. Chronic lower extremity edema and elevated skin pressure will result in skin hyperpigmentation. Some patients may even develop skin ulcers.
Obstructed venous reflux. Multiple occurrences of deep vein thrombosis will result in permanent venous obstruction.
Post-phlebitis syndrome. Recurrent pain or discomfort and edema in the affected limb. This symptom may be long or short.
Heart attack or stroke.
A hole in the top of the heart allows blood to flow directly from the right heart to the left heart – either in the upper part of the heart (atria) or in the lower part of the heart (ventricles) – and a blood clot in traffic can lead to a heart attack or stroke. This complication is rare.
Prevention of DVT and pulmonary embolism
Although more than 200,000 patients in the United States develop venous thrombosis each year, the vast majority of DVTs and pulmonary embolisms can be prevented with a few simple approaches. Some are used in hospitals and some can be employed while traveling.
In-hospital prevention steps
Heparin or warfarin therapy. Anticoagulants such as heparin and warfarin can be used before and after surgery, in patients with heart attacks or strokes who are at high risk for thrombosis.
Use compression. Compression packs or compression stockings provide continuous compression of the leg, allowing the veins and leg muscles to transport blood more efficiently. They can provide a safe, easy and inexpensive way to give blood flow after surgery.
Be active early and consistently after surgery.
Gastrocnemius exercises. Moving the gastrocnemius muscle after surgery can be an effective way to promote blood flow.
Use of pneumatic compression devices. This treatment uses automatic compression in the gastrocnemius area, massaging the lower extremity veins for a few seconds at a time.
Steps for prevention while traveling
1. Being sedentary in a car or on a flight will increase the likelihood of leg vein thrombosis. Means of prevention include
2.Walk around the cabin for a short time every hour. If you are a driver, stop once an hour and walk around the car a few times.
3. Contract and rotate your ankles or squeeze your legs in the front row of seats. Or move your big toe up and down.
4, contract your gastrocnemius.
5. Drink as much water as possible before and during the flight. Dehydration may lead to blood clot formation.
6.Wear compression stockings as recommended by your doctor to improve blood circulation.