Venous thrombosis

Introduction to venous thrombosis Venous thrombosis (phlebothrombosis) is caused by various causes of lowering the pressure of the venous return of the calf, leading to thrombosis. basic knowledge The proportion of illness: 0.0025% Susceptible people: no special people Mode of infection: non-infectious Complications: pulmonary hypertension pulmonary embolism

Cause of venous thrombosis

(1) Causes of the disease

The disease is divided into two types: infectious and non-infective.

Infectious people are more common in acute infections, childbirth, pelvic or abdominal surgery, non-infectious people are caused by blood stasis, and more common in the posterior vein of the calf.

(two) pathogenesis

The calf venous return pressure is reduced due to various reasons, blood viscosity and platelet increase, blood coagulation is increased, when the blood vessel is slightly damaged, it can promote platelet adhesion to local thrombosis, and then fibrin deposition causes thrombus to increase, resulting in tube The cavity is occluded and even spreads to nearby or distant veins.

Venous thrombosis prevention

prevention:

The prevention of venous thrombosis includes two aspects. The first is to pay attention to living habits and avoid the formation of venous thrombosis. The other aspect is to pay attention to daily life and avoid the thrombosis that has already formed.

After venous thrombosis, if it is confined to the calf vein, the thrombus can gradually become mechanized, the blood flow recanalizes, most of the symptoms remain, and a few spread up to the femoral vein or the iliac vein. Therefore, the process is often gradual and difficult to diagnose in time. Development of chronic lower extremity venous insufficiency, limb swelling is not easy to subside. Because the deep venous valve is destroyed during thrombosis and inflammation, even if the blood flow is recanalized, the hydrostatic pressure generated by gravity causes the cellulose in the tissue to accumulate, the fat connective tissue hardens, the skin produces stasis dermatitis, and even the vein Stasis ulcers cause a certain degree of sickness of the limbs.

The early stage of deep venous thrombosis of the lower extremities is prone to shedding. If the embolus is large, embolization in the left and right pulmonary artery trunk can cause large pulmonary embolism, which is often one of the causes of sudden death. Therefore, prevention of venous thrombosis in the lower extremities is very important.

Patients with old age, obesity and previous thrombophlebitis should pay special attention to strengthening prevention. Encourage fractures, trauma and postoperative patients to actively move limbs, and deep breathing exercise to promote venous return. Get out of bed as early as possible. For pelvic and lower extremity surgery, the operation should be gentle to avoid damage to the blood vessels, and wear elastic stockings after surgery to promote venous return of the lower extremities. For patients undergoing surgery, heparin or dextran may be used to reduce platelet activity in order to counteract hypercoagulable conditions that may occur after surgery. Deep vein thrombosis is mainly based on non-surgical treatment. In the acute phase, bed rest is required, and raising the affected limb can relieve pain and cause local inflammation to subside. In order to prevent the spread of blood clots, heparin and coumarin drugs are used for anticoagulant therapy. In order to prevent the venous function caused by the thrombus, thrombolytic therapy should be started in the early stage of the disease. The commonly used drugs are streptokinase and urokinase.

In order to prevent pulmonary embolism, venous thrombectomy can be performed within 48 hours after iliac vein thrombosis. For patients with a long course of disease, difficult to remove the thrombus and risk of pulmonary embolism, a filter plug device can be placed in or outside the inferior vena cava to prevent pulmonary embolism.

Venous ligation: ligation of the vein above the thrombus can prevent the occurrence of pulmonary embolism.

Venous thrombosis complications Complications pulmonary hypertension pulmonary embolism

It can cause pulmonary embolism and can be secondary to pulmonary hypertension.

Symptoms of venous thrombosis Common symptoms Low fever Skin temperature rise Skin temperature reduction Venous thrombosis Trigeminal area tenderness Variceal edema edema Calf calf muscle pain... Migratory superficial vein thrombosis

According to the different sites of thrombosis, it can be divided into two categories.

Superficial vein thrombosis

Often involving the great saphenous vein or small saphenous vein or its genital branch, mostly on the basis of varicose veins, the main feature is the pain in the thrombosis site, the surface of the superficial vein has a red, low-heat cord, tender, around Redness and swelling, the embolus is not easy to fall off, generally does not cause pulmonary embolism. In addition, migratory superficial vein thrombosis is often a suggestive symptom of cancer.

2. Deep vein thrombosis

According to its location and condition, it can be divided into the following two types.

(1) deep vein thrombosis of the calf: often occurs in the deep veins of the calf, such as the posterior tibial vein and the iliac vein, etc., more common in patients with less bed movement, often occurs in the second week after surgery, the left lower limb is the most common, It is characterized by pain and tenderness in the lower leg muscles, severe pain after exercise, and more dorsiflexion in the foot. The systemic symptoms are not significant. There may be Homan's sign when the test is performed, that is, the calf is straight, the foot is dorsiflexed, and the gastrocnemius is inside. The diseased vein is affected by traction and pain, and the circumference of the gastrocnemius muscle is thicker than the healthy side by more than 5 cm.

(2) , femoral vein thrombosis: can be secondary to the calf vein thrombosis, but more than the primary iliac vein, common in postpartum, rapid onset, severe diffuse edema of the affected limb, increased skin temperature or slightly convulsions Superficial vein dilatation, unbearable pain in the inner thigh and significant tenderness along the vein, especially in the trigone area, the systemic symptoms are not heavy.

Deep vein thrombosis due to invasion of the main vein, at the same time can produce peri-venous inflammation, affecting adjacent lymphatic vessels or causing arterial spasm, so the symptoms and signs are heavier, in addition, serious complications can occur, when the thrombus is extended to the inferior vena cava, It can cause pulmonary embolism, sometimes the first symptom of the disease, and can be secondary to pulmonary hypertension.

Venous thrombosis examination

Histopathology: Fresh blood clots in large veins are usually mixed. The length of the thrombus is usually stopped at the effective branch of a blood vessel. After thrombus formation, thrombolysis can occur, and fibroblasts invade to form new granulation. The tissue is further mechanized and forms new blood vessels and recanalization. If connective tissue hyperplasia and scar formation, the diseased vein becomes a sclerotic cord-like lesion.

Diagnosis and differentiation of venous thrombosis

Diagnostic criteria

Superficial vein thrombosis

It is very similar to the clinical manifestations of thrombophlebitis, it is difficult to identify, and the clinical superficial thrombotic venous disease is mostly thrombophlebitis rather than venous thrombosis, so the diagnosis of this type of disease is generally thrombophlebitis .

2. Calf deep vein thrombosis

According to the pain and tenderness of the lower leg muscles, the increase in the circumference of the gastrocnemius muscle and the positive Homan sign can be confirmed.

3. , femoral vein thrombosis

According to swelling of the lower extremities, pain and tenderness in the trigone, skin temperature is reduced, color changes and superficial varices can be diagnosed.

Differential diagnosis

Superficial vein thrombosis

It is very similar to the clinical manifestations of thrombophlebitis, it is difficult to identify, and the clinical superficial thrombotic venous disease is mostly thrombophlebitis rather than venous thrombosis, so the diagnosis of this type of disease is generally thrombophlebitis .

2. Calf deep vein thrombosis

It should be identified with other diseases involving the gastrocnemius muscle, such as local soft tissue infections.

3. , femoral vein thrombosis

Most of the deep vein thrombosis can be characterized by unilateral lower extremity edema, which should be analyzed and differentiated from lymphedema and edema caused by heart, liver and kidney diseases.

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