What is deep vein thrombosis?
Deep vein thrombosis (DVT) is a type of thrombotic disease. It is a venous reflux disorder caused by abnormal clotting of blood in the deep veins, mostly in the lower extremities; thrombosis can cause pulmonary embolism (PE), and the two together are called venous thromboembolism (VTE).
What are the main risks of DVT?
The main consequences of DVT are pulmonary artery embolism and post-thrombotic syndrome (PTS). When DVT is not diagnosed and managed in the acute phase, some clots may dislodge and cause embolism of vital organs, such as the lungs, leading to death. Other patients are not spared from the sequelae of chronic thrombosis, which causes long-term illness and affects their ability to live and work.
What are the characteristics of deep vein thrombosis?
There are three major features: high morbidity, high mortality and high sequelae.
1, high incidence: the average annual incidence of deep vein thrombosis in the population is 0.15%. The incidence rate is the highest in Caucasians, and the incidence rate in Asia is lower than that in Europe and America, which is about 1/5 according to the current survey. Deep vein thrombosis is recognized as one of the most difficult to treat and potentially life-threatening common diseases in modern medicine.
2, high mortality: symptomatic deep vein thrombosis about 10% complicate symptomatic pulmonary embolism, proximal deep vein thrombosis untreated leads to symptomatic pulmonary embolism up to 26%-50%, pulmonary embolism in 10% for fatal pulmonary infarction, 23% pulmonary embolism before the diagnosis of death.
3, high sequelae: two years after the first episode of deep vein thrombosis, the incidence of post-thrombotic syndrome is as high as 20%-50%; 6 months after the first episode of pulmonary embolism, 3.8% develop into chronic thromboembolic pulmonary hypertension (CTPH). And the recurrence rate of venous thromboembolism can be as high as 50% within 10 years.
What are the most common limbs for deep vein thrombosis?
Deep vein thrombosis mostly occurs in the lower extremity, upper extremity DVT only accounts for 1% to 4% of all DVT; among the lower extremity DVT, the left side is more common than the right side, which may be related to the longer path of the left iliac vein and the right iliac artery crossing it, so that the left iliac vein is compressed to different degrees.
What is upper extremity deep vein thromboembolism?
Upper extremity deep vein thrombeembolism (AUEDVT) is a thrombosis involving the subclavian, axillary and brachial veins.
What is the main cause of upper extremity deep vein thromboembolism?
Primary upper extremity deep vein thrombosis accounts for 20-25% of thrombosis, mostly unprovoked, but can be associated with easy embolism, thoracic outlet syndrome or exercise related. Secondary upper extremity DVT accounts for 75-80% of thrombosis, mostly due to placement of central venous catheters, pacemakers or malignancy.
What are the main symptoms of upper extremity deep vein thrombosis embolism?
The symptoms of upper extremity DVT are mainly edema, pain or skin discoloration of the affected extremity, which may be accompanied by dilated lateral veins (arm, neck, chest, etc.).
What are the main consequences of an upper extremity DVT embolism?
Complications of pulmonary embolism are seen in 1/3 of patients with upper extremity DVT, with sequelae of PTS of the arm and recurrence rates of 2.0% (1 year), 4.2% (2 years) and 7.7% (5 years).
How is upper extremity deep vein thromboembolism treated?
Treatment for upper extremity DVT is the same as for lower extremity DVT and is based on standard anticoagulation regimens. Thrombolysis, catheterization techniques and filter placement are used in selective cases.
How many types of lower extremity DVT are there?
There are three types, peripheral, central and mixed, depending on the location of the embolized vessel.
What are the characteristics of each type of lower extremity deep vein thrombosis?
1.Peripheral type: also called calf muscle plexus thrombosis, because the thrombus is limited, most of the symptoms are mild. Small emboli dislodged can cause mild pulmonary artery embolism, which is often neglected clinically. The main clinical manifestations are pain and mild swelling of the calf and limitation of movement. The main signs are pain caused by pulling the gastrocnemius muscle during foot dorsiflexion (positive Homan’s sign) and gastrocnemius muscle pressure pain (positive Neuhof’s sign).
2. Central type: also called iliofemoral vein thrombosis. It is more common on the left side, manifesting as swelling below the buttocks, anger in the lower limbs, groin and superficial veins of the affected abdominal wall, elevated skin temperature and pressure pain toward the deep veins. Dislodged thrombus can lead to pulmonary embolism, threatening the patient’s life.
3.Mixed type：Thrombosis in both deep veins and muscle plexus of the whole lower limb. It can be extended from central type or peripheral type, and its clinical manifestations are not easy to distinguish from central type.