Thrombosis

Thrombosis occurs when a blood clot forms within a blood vessel, either venous or arterial, restricting the normal flow of blood and causing health manifestations.

• If a blood clot plugs a vein, it is known as "venous thrombosis." Veins transport blood to the heart from the whole human body. There are two forms of thrombosis: Deep vein thrombosis (DVT) and superficial vein thrombosis.
• If a thrombus plugs an artery, it is known as "arterial thrombosis." Arteries transport oxygen-rich blood to the whole human body.

Acute venous and arterial thrombosis are the most prevalent causes of mortality in wealthy nations. Mortality varies according to the site and severity of the thrombosis, with myocardial injury and brain hemorrhage or stroke responsible for the majority of thrombosis-related deaths.

It can be due to multiple factors such as:

• Lack of mobility
• Fracture of the long bones
• A variety of medications
• Overweight
• Hereditary diseases, or a higher risk of developing a certain condition due to your genes.
• Autoimmune diseases 
• Birth control medicine

Arterial thrombosis can be induced by arteriosclerosis, which is the stiffening of the vessels. This occurs if fatty or calcium particles clog the arterial lining. This can cause fatty material to build up in the arterial walls. This plaque has the potential to pop, resulting in a blood clot.

• If thrombosis develops in the coronary arteries (arteries that supply blood to the heart), this might result in a heart attack.
• A stroke can result from arterial thrombosis in a blood vessel in the brain.

The epidemiology differs based on whether the thrombosis is venous or arterial, provoked or spontaneous, and if it is the very first recurrent bout. The yearly incidence of venous thromboembolism, which comprises deep vein thrombosis and pulmonary embolism, is one per ten thousand at childbearing age and one per hundred at old age. According to research, people of European ancestry have a higher risk of venous thrombosis than non-European origin.

The following are some of the risk factors for venous thrombosis:

• Pregnancy
• If movement is limited,
• A family history of DVT
• DVT in the past
• Birth control pills
• A central venous catheter
• Getting older
• Cigarette smoking
• Obesity
• Some diseases, such as cancer, cardiovascular disease, lung illness, or Crohn's disease.

The following are some of the risk factors for arterial thrombosis:

• Smoking
• Diabetes
• Uncontrolled blood pressure
• High levels of cholesterol.
• Obesity
• Unhealthy eating habits
• Family history 
• Lack of mobility and sedentary lifestyle

The clinical signs of thrombosis differ based on the suspected site and severity of the thrombosis.

• Swelling, discomfort, and erythema of the diseased region are common DVT symptoms.
• Abdominal discomfort, fluid in the abdomen, and an enlarged liver are all signs of an oversized liver.
• Headaches, blurred vision, or any of the other signs of a stroke, like facial and leg paralysis in one part of the body, as well as blackouts.
• Pain in the chest indicates MI or pulmonary embolism.
• Numbness or fatigue.

The sort of imaging method utilized will be determined by the type of thrombus you have and its location.MRI, MRA, or CT scans are all options.

Modified Wells' criteria: Whenever patients arrive at the emergency room with clinical manifestations that imply venous thrombosis, a scale called the modified Wells' criteria is used to direct additional diagnostic testing.

D-dimer: A serum D-dimer test must be performed on patients with a high Wells score. Its increase may be used to identify venous thrombosis and is quite sensitive. A negative D-dimer test assists in ruling out the diagnosis and avoiding costly imaging investigations or anticoagulant therapy.

Duplex US: It is a scan of the lower or upper limbs used to check for DVT.

A CT angiogram and ventilation/perfusion scanning (V/Q scan): These are suggested imaging techniques for pulmonary embolism.

Hypercoagulable workup: A focused hypercoagulable workup might be needed in individuals suspected of carrying an underlying genetic thrombophilia. These tests include protein C and S, antithrombin III, and factor V Leiden or Prothrombin gene mutations.

Cancer screening: All individuals should have age-appropriate cancer screening.

• One of the main differential diagnoses for thrombosis is embolism. In an embolism, a clot forms in a specific area, causing artery stenosis. The clot in an embolism moves from one primary location to another.
• Patients with a likelihood of systemic infection, a background of IV drug usage, or probable or proven bacterial endocarditis must be evaluated for septic emboli.
• Chronic peripheral vascular disease can cause comparable symptoms in the limbs, and if this is detected, patients should be evaluated for vascular surgery.

Management for thrombosis is determined by whether the thrombosis is in a venous or an arterial territory, the patient's health, and the likelihood of medication consequences.

Medications

Anticoagulants: Anticoagulants, often called blood thinners, are chemical agents that inhibit or diminish blood coagulation, lengthening the time it takes for blood to clot. Anticoagulants such as warfarin and vitamin K antagonists can be given orally to minimize the risk of thromboembolism. Heparin can also be administered concurrently if a more robust reaction is necessary. Because any anticoagulant carries the likelihood of bleeding as an adverse reaction, the international normalized ratio (INR) of blood is measured routinely.

Thrombolysis: Thrombolysis is the medical demolition of clots by providing thrombolytic medications, such as recombinant tissue plasminogen activator, that boost the body's natural enzymes' ability to destroy clots.

Antiplatelets: Because a high proportion of platelets characterizes arterial thrombosis, inhibiting platelet activation with antiplatelet medicines like aspirin may minimize the risk of relapse or advancement.

Procedure

When arterial thrombosis produces acute limb ischemia, surgery may be required. To expand the problematic arteries, thin catheters are inserted. However, sometimes the doctor may recommend stent placement. A stent is a wire mesh tube that keeps a blood vessel open and prevents it from shutting down.

The prognosis for thrombosis depends on the kind of thrombosis, the site of the thrombosis, the intensity of the thrombosis, the retention of precipitating risk factors and morbidities, and whether the thrombosis is the first or successive episode. Recurrent VTE is more common among patients with venous thrombosis than in the general population, especially with baseline triggering health risks.

• If you've had an operation or have been on physical restraint for whatever reason, try to get up and exercise as frequently as possible. If you're going to be sitting for a long time, you really shouldn't cross your legs since this might cut off blood flow. If you're driving hundreds of kilometers, take a break every hour or so and go for exercise.
• If you're flying, get up and move about every now and then. If you're unable to do so, work on your calf muscles. Raise your heels while keeping your toes on the ground, then raise your toes while keeping your heels on the ground.
• DVT is more likely to occur if you smoke, so you better quit smoking.
• Exercise and maintain a healthy weight. Obesity raises the risk of DVT. Exercise reduces the risk of thrombosis, which is especially significant for individuals who have to sit for hours or travel long distances on flights.

Our clinical experts continually monitor the health and medical content posted on CURA4U, and we update our blogs and articles when new information becomes available. Last reviewed by Dr.Saad Zia on May 31, 2023.

References

What is Thrombosis? | North American Thrombosis Forum

https://thrombosis.org/patients/what-is-thrombosis/

Thrombosis | Johns Hopkins Medicine

https://www.hopkinsmedicine.org/health/conditions-and-diseases/thrombosis#:~:text=Thrombosis%20occurs%20when%20blood%20clots%20block%20veins%20or%20arteries.,a%20stroke%20or%20heart%20attack.