thrombophlebitis
Introduction
Introduction to thrombophlebitis Thrombophlebitis is an acute non-suppurative inflammation of the venous lumen accompanied by thrombosis. It is a common vascular thrombotic disease, and the lesion mainly involves the superficial veins and deep veins of the extremities. Thrombosis can cause inflammation, and inflammation can also cause blood clots, which are mutually causal. Includes thrombotic superficial phlebitis and deep thrombosis. basic knowledge The proportion of illness: 0.003% Susceptible people: no special people Mode of infection: non-infectious Complications: thrombosis, venous thrombosis, pulmonary embolism, stasis dermatitis
Cause
Cause of thrombophlebitis
Slow blood flow and eddy current formation (35%):
It is an important condition for thrombosis, such as prolonged bed rest, heart failure, tumor compression, varicose veins and venous tumors, elevated intra-abdominal and pelvic pressure during pregnancy, weakness of lower limb muscles, etc., can cause slow blood flow and promote thrombosis. The reason is that the slow blood flow makes the axial flow wide, which is beneficial to the edge and agglutination of the platelets, and increases the contact with the endometrium and the chance of adhesion; at the same time, the platelets adhered and a small amount of coagulation active substances already present locally, because The blood flow is slow and cannot be diluted and removed, and it gathers locally to reach the necessary concentration of blood coagulation; when the blood flow is slow, the vascular endothelial cells are susceptible to damage, collagen exposure occurs, and thrombus is easily formed. In addition, varicose veins and venous tumors After the formation, the local blood flow state changes, creating a vortex, causing platelets to precipitate from the bloodstream, precipitation and aggregation, and easily lead to thrombosis.
Increased blood coagulation (30%):
Increased platelet or coagulation factor, decreased fibrinolytic activity, increased blood coagulation and thrombosis, loss of water and blood loss caused by various causes, resulting in blood concentration; increased platelet count and viscosity; fibrinogen, prothrombin and Increased levels of other clotting factors; advanced cancers such as pancreatic cancer and malignant tumors of the lungs, which release a coagulase-like substance due to tumor necrosis, activate the exogenous coagulation system; certain allergic diseases may cause platelets and red blood cells Destruction, release of platelet factor 3 and erythrotoxin, activation of prothrombin, etc., are conducive to thrombosis.
Intimal injury (30%):
Various causes such as trauma (intravenous sclerotherapy, hypertonic solution, anticancer drugs, contrast agents, intravenous cannula), hypoxia, chemicals (smoking, hypercholesterolemia), infection (bacterial toxins), tumor cell invasion, etc. It can cause damage to vascular endothelial cells, leading to the exposure of rough subendothelial collagen fibers, promoting platelet aggregation, and the adhesion of platelets and endothelial cells to release ADP and thromboxane A2, which further promote platelet aggregation; and simultaneously exposed collagen fibers Activation of the XII factor in the blood, thereby initiating the endogenous coagulation system, and the tissue coagulation factor released from the intima initiates the exogenous coagulation system, thereby causing blood coagulation and promoting thrombosis.
Venous thrombosis can occur in all parts of the body, the most common are the saphenous vein and its branches, the rare iliac vein, the subclavian vein, the cephalic vein, the venous vein and the superficial vein of the chest, abdominal wall, lower limb or upper limb. After thrombosis, due to extensive anastomotic branch, it is not easy to cause circulatory disorder and tissue edema; on the contrary, larger deep veins, such as iliac vein, iliac vein and upper and lower vena cava, after thrombosis, due to stenosis or Occlusion, obstructing blood return, and due to the development of the external end of the thrombus, causing the venous pressure to rise, so that the capillaries and venules are congested, the tissue is hypoxic, and the capillary osmotic pressure is increased, resulting in tissue edema, when the lymphatic vessels are under pressure The edema is more pronounced. If the new blood vessels are formed or recanalized and the collateral circulation is established, the blood circulation of the affected area can be maintained. If these new structures are well established, the venous return can be improved (it is more difficult to recover when the venous valve is damaged). On the contrary, it leads to chronic venous insufficiency, post-phlebitis syndrome or a part of the thrombus falling off into an embolus.
The difference between venous thrombosis and thrombophlebitis is that the former has a major role in slow blood flow and increased blood coagulation. The change in the vein wall is not obvious; the latter is a thrombus on the basis of inflammation of the vein wall, during pathological anatomy. It was found that there was a thrombus in the venous cavity, and there was no clinical manifestation of thrombophlebitis before birth. On the contrary, the vascular wall had different degrees of inflammatory reaction within a few hours after thrombus formation, so it is difficult to clearly define the two in clinical The distinction is made, so they can be collectively referred to as thrombophlebitis.
The fresh thrombus of the large vein is usually mixed. A typical thrombus is divided into three parts: the head, the body and the tail. The sticky white platelets and the mixed white blood cells form a grayish white thrombus as the head on the intima of the diseased vein. Department; on the basis of white blood clots, attached more white blood cells and fibrin and a large number of red blood cells to form a mixed thrombus as a body; when the formed thrombus further develops the filling lumen, local blood flow stops, the blood is rapid Coagulation, forming a dark red red thrombus as the tail, the length of the thrombus is generally stopped at an effective vascular branch, and after thrombus formation, it dissolves due to the action of plasmin and neutrophil proteolytic enzymes, in thrombosis In the next 5 days, fibroblasts invade, forming new granulation tissue, and then mechanization and new blood vessel formation and recanalization. If connective tissue hyperplasia and scar formation, the diseased vein becomes a sclerotic cord-like lesion.
The histopathology of thrombophlebitis caused by different causes is not completely the same, such as suppurative phlebitis, the wall inflammation is significant, and neutrophil infiltration is the main; chemical phlebitis is more obvious intimal hyperplasia; In phlebitis caused by tumor and heart failure, the inflammation of the wall is relatively mild; in migratory thrombophlebitis, the fibroblasts in the wall and surrounding tissues are more severe.
Prevention
Thrombophlebitis prevention
Different methods are used depending on the patient's condition, which is generally:
1. For long-term bed rest, you should do deep breathing and coughing to promote blood circulation; if infusion patients should avoid using irritating liquids as much as possible.
2. After the operation, the patient is encouraged to take deep breathing exercises, and the lower limbs, especially the foot, are stretched out and get out of bed as soon as possible.
3. Active treatment of varicose veins of the lower extremities.
4. Patients with venous thrombosis in the lower leg should be treated early to prevent the thrombus from developing proximally.
Complication
Complications of thrombophlebitis Complications thrombosis venous thrombosis pulmonary embolism stasis dermatitis
Deep vein thrombosis can cause serious complications:
1 extended venous thrombosis: such as calf vein thrombosis has the possibility of upward development to the femoral, iliac crest and even the inferior vena cava;
2 thromboembolism: such as pulmonary embolism, can occur within a few hours or days after thrombosis;
3 chronic venous insufficiency after phlebitis: as in the calf, when the venous valve is seriously damaged, the collateral circulation is not fully established, that is, it is prone to serious conditions, first of all, edema of the lower leg, varicose veins gradually, skin pigmentation, and finally Stasis dermatitis, stasis subcutaneous sclerosis and stasis ulcers.
Symptom
Common symptoms of thrombotic venous inflammation, elevated skin temperature, straight leg extension test, positive edema, local venous sinusoidal subcutaneous vein, reticular anger, diffuse edema of lower extremity, burn wound, eschar, eschar... White swollen triangle
Can be divided into the following types of diseases.
Superficial thrombophlebitis
Clinically, it is often divided into superficial benign thrombophlebitis and migratory thrombophlebitis. The difference is mainly that except for the cause, the former involves a vein and continues to develop upward; while the latter has no form. Often one or several veins are involved at the same time or in succession, and they repeatedly recur.
(1) superficial benign thrombophlebitis: superficial benign thrombophlebitis, according to the cause of the disease; intravenous sclerotherapy, hypertonic solution, anticancer drugs, etc., causing chemical stimulation on the inner membrane , causing extensive damage, phlebitis and thrombosis, called chemical phlebitis, by intravenous injection, long-term insertion of plastic tubes, blows, sprains and other mechanical damage caused by local phlebitis called traumatic phlebitis, etc. .
Superficial benign thrombophlebitis is more common in the saphenous vein of the lower extremity and its branches and veins of the upper extremities. It is often limited to one vein. In severe cases, it develops to the proximal end and its large branches. In acute attacks, it can touch the pain along the diseased vein. A tender subcutaneous hard cord, or a segmental distribution of oval nodules, which occurs when the surrounding tissue is involved, resulting in redness and temperature rise in adjacent skin, which may move with the skin, and may have mild body after the onset. Sexual symptoms, but white blood cells generally do not rise, the pain is relieved when healed, the redness and swelling subsided, leaving pigmentation spots or subcutaneous hard cords. When the collateral circulation is established and recanalized, the hard cord may gradually disappear due to superficial venous lesions. Blood reflux is generally unaffected, so it does not cause edema of the extremities. If deep venous lesions or venous valves are involved, severe tissue edema and chronic venous insufficiency may occur.
(2) migratory thrombophlebitis: mainly involves superficial veins, and deep veins such as brain, liver, kidney, mesentery and lungs can also occur, but the lower limbs, hip and abdominal wall are common, showing segmentality. Subcutaneous hard cord or induration, pain and tenderness, adjacent skin redness, subsided after 2 to 4 weeks, leaving pigmentation spots, and new damage occurred in the other vein or another vein, so part of it subsided, part of new hair, As a result, there are different stages of damage in several parts. The cause of this disease is unknown, but it is closely related to two diseases: 1 It is often an early manifestation of latent visceral cancer, and the primary visceral cancer involves the stomach, lung, pancreas and gallbladder. The site is most closely related to pancreatic body and pancreatic cancer. 2 It is closely related to thromboangiitis obliterans. It is a clinical manifestation of early stage or a whole stage of the disease. Thrombophlebitis of Behcet disease is also May belong to this type of disease, the difference is that the latter deep and shallow different canal veins can occur, while the former is mainly invading the superficial small and medium veins.
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 lower leg: often occurs in the deep veins of the lower leg, such as the posterior tibial vein and the iliac vein. The mechanical thrombus may cause local venous obstruction and inflammatory reaction. Because the thrombus is generally small, the inflammation is light, The blood return is not large, and the symptoms are generally not obvious. Usually, the muscles are heavy and painful after the activity. In severe cases, there is pain. A few patients will have obvious symptoms when the thrombus spreads to the proximal side and affects the main vein. For example, if there is obvious tissue edema, local symptoms and fever, the characteristic manifestation is pain and tenderness in the gastrocnemius muscle. When the examination is performed, the calf is straightened, the foot is dorsiflexed, and the vein of the gastrocnemius is pulled by the vein to cause pain, which is called Homan's sign. Homan's sign positive, deep gastrocnemius tenderness (Neuhof sign) and passive extension of the foot or dorsiflexion caused by pain in the lower leg, all contribute to the diagnosis of deep venous thrombosis of the lower leg. In addition, the circumference of the gastrocnemius muscle is more than 5 cm larger than the healthy side. Mild edema of the ankle with superficial venous engorgement may also be a manifestation of deep vein thrombosis. Although deep vein thrombosis of the lower leg can occur on both sides, but not Given symmetric, may be distinguished from edema caused by the heart, liver and kidney disease.
(2) , femoral thrombophlebitis: typical performance is:
1 diffuse edema of the entire lower extremity;
2 subcutaneous vein engorgement and skin bruising;
3 triangles tenderness, often fever, tachycardia and increased white blood cell count, due to diffuse edema caused by skin tension, pale, depressed depression; subcutaneous veins are reticular anger; there are intolerable pain and along The tenderness of the veins, especially in the trigeminal region, is called phlegmasia alba dolens. If the venous thrombosis develops not only in the main vein, but also in the broad branches or deep muscle tissues, the capillary When the vascular pressure and tissue pressure exceed the arterial pressure, severe tissue edema may occur, the local temperature may decrease, diffuse bruising may appear in the calf and the back of the foot, and the femoral artery spasm and arterial pulsation may disappear, and finally the tissue dystrophy or even the vein may occur. Gangrene, this condition is called phlegmasia cerulea dolens or blue thrombophlebitis. Because the above lesions are mainly thrombosis in the main vein, the lumen is occluded, and the blood circulation is affected. Large, at the same time can produce inflammation around the vein, affecting adjacent lymphatic vessels or causing arterial spasm, so symptoms and signs are Serious.
Examine
Examination of thrombophlebitis
1. Iodine-131 fibrinogen test: Adsorption to the thrombus formation site after intravenous injection, mainly for thrombosis that is still formed, so early detection of occult thrombosis.
2. Determination of plasma fibrinogen.
3. Partial thromboplastin test.
4. Doppler ultrasonography and electrical impedance plethysmography: can reliably determine the thrombosis of the main vein, check non-invasive.
5. Venous angiography: direct visualization of the vein can effectively determine the location of the occlusion vein, the degree of collateral circulation and the establishment of the collateral circulation.
6. Intravenous pressure measurement: Pulmonary pressure was measured by puncture of the dorsal vein of the foot, and the normal was 1.18 to 1.47 kPa.
Diagnosis
Diagnosis and diagnosis of thrombophlebitis
diagnosis
1. Superficial thrombophlebitis: The diagnosis is based on the subcutaneous hard cord along the superficial vein. If it is a small vein, it may be a nodule, but it is not spherical, and the adjacent skin is red, swollen, painful and tender.
2. Calf deep vein thrombosis: The diagnosis is based on pain and tenderness of the gastrocnemius muscle, as well as the increase in the circumference of the calf and the positive Homan sign.
3. , femoral vein thrombosis: swelling of the lower extremities, pain and tenderness along the femoral vein, especially in the trigone, skin temperature reduction, color change and superficial venous engorgement.
Differential diagnosis
Venous edema caused by chronic deep phlebitis needs to be differentiated from lymphedema.
