Deep Vein Thrombosis: Everything You Should Know About Deep Vein Thrombosis and KOL #1 Dr. Harry Roger Büller

DVT stands for DEEP VEIN THROMBOSIS. DVT is a partial or complete obstruction of the lumen of the venous vessel due to a fibrin thrombus. DVT causes a reduction in blood supply to surrounding tissues and a local inflammatory reaction with the capacity to embolize any blood vessel in the body.

Deep vein thrombosis (DVT) is a disease with a high mortality rate. It is a reason for consultation in adults that happens relatively frequently.

Deep vein thrombosis of the lower limbs is the most frequent and can be proximal (femoral, popliteal, and iliac veins) or distal (affecting the distal branches of the popliteal veins). These venous thrombi can become detached, migrate through the venous circulation to the right ventricle, and subsequently lodged in the pulmonary arteries, causing pulmonary embolism (PE).

DVT: Key Researches around the world

The most prominent DVT researchers are: Paolo Prandoni (Arianna Anticoagulazione Foundation), Harry Roger Büller (Amsterdam University) and John Heit (Mayo Clinic).

Before discussing a thrombotic event, it is necessary to mention Virchow's Triad: blood hypercoagulability, endothelial injury, and stasis. Hypercoagulability is the increased predisposition of an individual to excessive or inappropriate formation of blood clots; this condition can be hereditary or acquired.

This condition causes alteration in the blood vessel, called tortuosity, and affects the vessel's endothelium, leading to adhesion and blood thrombi formation due to blood stasis (stagnation), resulting in slower blood flow.

DVT: Symptoms

The approach to lower limb deep vein thrombosis includes the clinical history, focusing on risk factors for developing thrombotic events, a complete physical examination, and risk stratification.

The symptoms are varied; the condition can be asymptomatic or symptomatic, manifested by a broad spectrum of signs and symptoms, so a timely diagnosis is essential.

Patients with venous thrombosis in the lower limbs generally present the following features:

• Edema
• Localized pain
• Swelling in one or both extremities
• Bruising or discoloration of the area
• Changes in pain perception
• Other less specific findings, such as bruising

In cases of pulmonary thromboembolism, a condition caused by the detachment of microthrombi into the pulmonary circulation, Symptoms may be absent, but it is important to note that it manifests with:

• Sweating
• Anxiety
• Dyspnea (sudden onset shortness of breath)
• Palpitations
• Chest pain
• Hemoptysis (coughing up blood)
• Dizziness
• Syncope
• Cyanosis

After the physical examination findings mentioned above, the physician should include a predictive model (Wells test) and the D-dimer test to complement the clinical diagnosis. Its results will indicate whether or not there is a need to perform the pertinent complementary examinations that confirm the risk of pulmonary thromboembolism.

On the other hand, laboratory tests can provide a differential diagnosis of other diseases, as well as the suspicious presence or complication of thromboembolism. Among them, the most requested are D-dimer and coagulation times, which allow the detection of hypercoagulable conditions.

However, it is crucial to remember that other conditions or diseases can raise D-dimer, such as burns, pregnancy, cancer, and kidney failure.

Another critical imaging study is the venous doppler ultrasound or echosonogram of the upper or lower limbs, being a simple, fast, safe, and non-invasive procedure. The doppler USG allows us to determine if there is occlusion of the lumen of a vessel and determines the diagnosis of venous thrombosis.

What is the ICD 10 code for Deep Vein Thrombosis?

The ICD / ICD 10 code for Deep Vein Thrombosis is "I82.40" (Acute embolism and thrombosis of unspecified deep veins of lower extremity).

Deep Vein Thrombosis: Causes

Multiple factors can contribute to the development of deep vein thrombosis. Among them are:

• Age greater than 60 years
• Cancer
• Smoking (including passive smokers)
• Use of estrogen receptor modulators (tamoxifen, raloxifen)
• Heart failure
• Hypercoagulable diseases

• Antiphospholipid antibody syndrome
• Antithrombin deficiency
• Factor V Leiden mutation (activated protein C resistance)
• Thrombocytopenia induced by heparin
• Hereditary fibrinolytic disorders
• Hyperhomocysteinemia
• Increased Factor VIII
• Increased factor XI
• Paroxysmal nocturnal hemoglobinuria
• Protein C deficiency
• Protein S deficiency
• Prothrombin gene mutation (GA variant)
• Immobilization of patients in bed
• Permeable venous catheters
• Extremity injuries
• Myeloproliferative neoplasm (hyperviscosity)
• Nephrotic syndrome
• Obesity
• Oral contraceptives or estrogen replacement therapy
• Pregnancy and puerperium
• History of venous thromboembolism
• Sickle cell disease
• Surgery within the previous three months
• Traumatisms in general

These risk factors predispose to different conditions leading to deep vein thrombosis in the upper and lower limbs.

Deep vein thrombosis of the lower limb is most often due to:

• Impaired venous return (e.g., in immobilized patients)
• Endothelial injury or dysfunction (e.g., after leg fractures)
• Hypercoagulability

Deep vein thrombosis of the upper limbs is most often due to:

• Endothelial injury generated by central venous catheters, pacemakers, or intravenous drug addiction.
• Tumor lesion compressing the superior vena cava (causing superior vena cava syndrome (symptoms such as facial swelling, dilated neck veins, and facial erythema).
• Hypercoagulable states or subclavian vein compression in the thoracic outlet (exertional thrombosis or Paget-Schroetter syndrome).

Thrombus formation leading to deep vein thrombosis usually begins at the cusps of the venous valves. Thrombi are composed of thrombin, fibrin, and erythrocytes with relatively few platelets (red thrombi); Without treatment, thrombi can spread proximally or into the lungs (pulmonary thromboembolism).

Treatment of deep vein thrombosis

The treatment of deep vein thrombosis should focus on prevention, taking into account those people with risk factors such as obesity, smoking, hypertension, sedentary lifestyle, and limited mobility (postoperative or during convalescence from medical illnesses) should be paramount.

If a patient has already presented deep vein thrombosis, the adequate treatment allows for avoiding or reducing complications in the short and long term.

Pharmacological treatment with parenteral anticoagulants has allowed a decrease in morbidity and mortality. The main objective of anticoagulation is not only to eradicate the existing thrombus but to prevent the formation of new clots.

Currently, the drugs used to treat deep vein thrombosis in the lower limbs are parenteral and oral anticoagulants, such as unfractionated heparin and low molecular weight heparin.

Studies show that low molecular weight heparin is the drug of first choice in managing thrombotic events unless the patient has a contraindication that does not allow its use.

Using these drugs two to four hours after initiation protects against future thrombotic events. Parenteral heparin should be co-administered with vitamin K antagonists such as warfarin for the first few days and with close control of clotting times and medical monitoring.

Subsequently, warfarin will be the maintenance medication to prevent further thrombotic events. The maintenance phase must be maintained for weeks or months, depending on the patient, because the objective of anticoagulation is to avoid the recurrence of thrombotic events, and the decision to continue or suspend treatment must be personalized and taken based on the risk of bleeding.

Another treatment option is the application of an inferior vena cava filter, which is a device inserted and moved through the venous system at the level of the femoral vein up to the inferior vena cava to locate and avoid the passage of emboli as well as their possible migration.

The indications for using this device are: presenting recurrent episodes of venous thrombosis in patients who have already received anticoagulant treatment, acute pulmonary edema, proximal venous thrombosis, or absolute contraindication for anticoagulant therapy.

Thrombolysis is a method that consists of administering a thrombotic drug into the venous system, aiming to eliminate the clot that obstructs a vessel's lumen. However, this method is uncommon due to the risk of bleeding, so a previous coagulation test is necessary to search for thrombophilias.

Likewise, other complications that limit the use of this procedure are hemolysis, cardiac tamponade, perforation of the pulmonary arteries, and bradycardia.

Contrast-enhanced venography confirms the diagnosis of DVT, but ultrasounds have replaced it due to being non-invasive, more readily performed, and nearly as accurate in detecting DVTs.

Venography can indicate whether the ultrasound results are typical, but the pretest suspicion of deep vein thrombosis is high. The downside would be an allergy to contrast agents.

Other tests include magnetic resonance, venography with intravenous contrast medium, and direct magnetic resonance imaging of thrombi, which is very useful in diagnosing pulmonary embolisms.

Surgery to treat deep vein thrombosis

Surgery is rarely necessary. However, in phlegmasia alba dolens or phlegmasia cerulea dolens, which do not respond to thrombolytics, it is essential to perform a thrombectomy, fasciotomy, or both to try to avoid gangrene that leads to limb loss.

Prevention of deep vein thrombosis:

Deep vein thrombosis (DVT) is a disease with high morbidity and mortality, so it is necessary to prevent it. There are two primary objectives for applying prophylactic measures: the physical ones, aimed at combating venous stasis, and the more effective pharmacological ones, aimed at reducing hypercoagulability. This favors the prevention of thromboembolic complications, the reduction of related mortality, or the long-term sequelae of venous thromboembolism, such as post-thrombotic syndrome.

For this, the prophylaxis of pulmonary thromboembolism consists of the application of physical and pharmacological measures, with a duration that depends on the evaluation of the thrombotic risk factors presented by each patient based on four main recommendations:

General measures

• Keep hydrated
• Avoid tobacco or smoking
• Eat a healthy diet to avoid being overweight
• Exercise regularly
• Take rest measures on long trips, as well as do flexion and extension exercises (pumping)
• Control of chronic diseases to avoid complications

Early mobilization

Includes active or passive mobilization and keeping the extremities elevated. Especially relevant after surgical interventions or limiting diseases that predispose to thromboembolic risks.

Mechanical methods

Use of gradual compression elastic stockings or intermittent pneumatic compression boots.

Pharmacological methods

They consist of subcutaneous (SC), oral or intravenous administration of heparin, unfractionated heparin (UFH), low molecular weight (LMWH), or pentasaccharide. The most recommended drug is subcutaneous low molecular-weight heparin in a single daily dose without laboratory monitoring.

Complications of deep vein thrombosis

Common complications of deep vein thrombosis include

• Chronic venous insufficiency
• Postphlebitic syndrome
• Pulmonary embolism

Chronic venous insufficiency is damage to the veins in the legs that prevents blood from flowing normally. Postphlebitic syndrome is a chronic venous insufficiency caused by a blood clot in the veins.

Pulmonary embolism (PE) depends on the size and number of emboli: small emboli can obstruct a small-caliber pulmonary artery, causing the death of a piece of lung tissue (pulmonary infarction). In the case of a large pulmonary embolus, it can block the pulmonary artery, thus causing arterial hypotension, hypoxemia, and sudden death.

Less commonly, deep vein thrombosis causes

• Leuko phlegmasia dolens or phlegmasia cerulea are both responsible for the development of venous gangrene if they are not diagnosed and treated on time.
• Infection in venous clots, in this phenomenon, is described as:
• Suppurative thrombophlebitis of the jugular vein (Lemierre's syndrome).
• Septic pelvic thrombophlebitis, in which postpartum pelvic thrombosis occurs, which then becomes infected and causes intermittent fever.
• Suppurative (septic) thrombophlebitis, a bacterial infection of a superficial peripheral vein, includes infection and clot formation that often occurs due to the placement of a venous catheter.

Venous thromboembolism in pregnancy

It is a significant cause of morbidity and mortality in pregnancy; it can occur due to the following:

• Capacitance and venous pressure in the legs increase, leading to stasis.
• Pregnancy causes some degree of hypercoagulability.

However, most thrombi and emboli develop postpartum and result from vascular trauma during delivery. The risk of developing deep vein thrombosis may increase for about six weeks after delivery. This risk is also higher with cesarean sections.

Conclusions:

Deep vein thrombosis is a pathological entity highly related to risk factors such as agents that cause hypercoagulability states and predisposing factors such as chronic diseases that affect circulation and favor venous stasis. Those associated with the use of drugs and devices such as venous catheters. Prevention and timely treatment decrease the risk of complications, and treatment with anticoagulant drugs is the choice for these patients.

 

Dr. Harry Roger Büller: KOL #1 for Deep Vein Thrombosis

According to KOL's technology, Dr. Harry Roger Büller is the top ranking Key Opinion Leader (worldwide) for Deep Vein Thrombosis. You can see Dr. Harry Roger Büller's KOL resume and other concepts for which they rank #1 worldwide.