Deep vein thrombosis of the lower extremities is a common disease. This disease can be followed by lower limb edema, secondary varicose veins, dermatitis, hyperpigmentation, depressed ulcers, etc., which seriously damage the health of working people. There are about 500,000 people suffer from this disease in the United States every year, and there are no statistics in China yet, but it is not uncommon.
1.Most often seen in postpartum, post-pelvic surgery, trauma, advanced cancer, coma or patients who are bedridden for a long time.
2.The onset of the disease is urgent, the affected limb is swollen and hard and painful, which is aggravated after activity, often accompanied by fever and rapid pulse.
3.The thrombus site is painful, cords can be found along the blood vessels, the limb distal to the thrombus or the whole limb is swollen, the skin is blue-purple, the skin temperature is reduced, the dorsal foot and posterior tibial artery pulsation is weakened or disappeared, or venous gangrene appears. When the thrombus extends into the inferior vena cava, edema is evident in both lower extremities, buttocks, lower abdomen, and external genitalia. When the thrombus occurs in the muscular plexus of the calf, Homans’ sign and Neuhof’s sign are positive.
4, Late thrombus absorption mechanization, often leaving venous insufficiency, birth superficial varicose veins, pigmentation, ulceration, swelling, etc., called deep vein thrombosis after syndrome. Divided into.
① Peripheral type. Mainly blood backflow.
② Central type. Blood reflux disorder is the main type.
③Mixed type. Both blood backflow and reflux obstruction are present.
5.Thrombus dislodgement may cause pulmonary embolism.
6.Radiofibrinogen test, Doppler ultrasound and venous flow mapping can help to diagnose. Venography can determine the diagnosis. Yang Bin, Department of Vascular Surgery, Jining First People’s Hospital
Treatment measures
I: Non-surgical therapeutic effect
1.Bed rest and elevation of affected limbs
Patients suffering from acute deep vein thrombosis need bed rest for 1~2 weeks to make the thrombus adhere tightly to the vein lining, reduce local pain and promote the inflammatory reaction to subside. During this period, avoid exertion to prevent thrombus dislodgement leading to pulmonary embolism. The affected limb should be elevated above the level of the heart, about 20-30 cm above the bed, and the knee joint should be placed in a slightly flexed position. If the elevation is appropriate, it is not necessary to use elastic bandage or wear elastic stockings. When you start to get up and move around, you need to wear elastic stockings or elastic bandages to moderately compress the superficial veins in order to increase the venous plus return flow as well as to maintain the minimum venous pressure and stop the development of lower limb edema. The time of using elastic stockings: ① for thrombophlebitis of deep or superficial veins of calf, it is generally not needed, but if edema appears in ankle and lower calf, it can be used for several weeks; ② for N and femoral vein thrombosis, it is generally used for no more than 6 weeks; ③ for iliofemoral vein thrombosis, it is used for 3 months first, and then removed intermittently, generally no more than 6 months, but if edema appears, it is necessary to continue to apply. Patients in the early stage, forbidden to stand and sit for a long time. For patients with heavy iliofemoral vein thrombosis, appropriate restrictions on standing and sitting, and elevation of the affected limb for 3 months, which can promote the establishment of lateral branch veins in the lower limbs to reduce lower limb edema.
2.Anti-coagulation therapy
This is the main modern treatment method for deep vein thrombosis. The correct use of anticoagulants can reduce the complication rate of F embolism and the sequelae of deep vein thrombosis. The effect is to prevent the continued growth of formed thrombi and the formation of new thrombi in other areas, and to promote the more rapid re-tubulation of thrombosed veins.
Indications: ① within 1 month after venous thrombosis; ② when there is a possibility of pulmonary embolism after venous thrombosis; ③ after thrombectomy.
Contraindications: ① bleeding quality; ② after abortion; ③ subacute endocarditis; ④ ulcer disease.
Commonly used anticoagulants include heparin and coumarin derivatives.
Heparin is an effective anticoagulant with rapid efficacy, which can effectively control blood coagulation after 10 minutes of intravenous injection. It has a short duration of action and is rapidly destroyed in the body, mostly by enzymes and in small part by renal excretion. After 3-6 hours of intravenous injection, the blood coagulation time can be restored to normal. Heparin aqueous solvent has two kinds of injections, 12500μ and 5000μ, each 100μ is equivalent to 1mg. general dose is calculated near Kensui 1~1.5mg/dkg/4~6h. The route of administration can be through the subcutaneous fat layer, intramuscular, or intravenous injection: ① deep fat layer injection: generally injected in the deep fat layer of the abdominal wall, with concentrated heparin solution (100mg/dml), the dose is calculated at 1 to 1.5mg per kg body weight. 1 injection every 8-12 hours; ② intramuscular injection: heparin dose of 50mg each time, 1 injection every 6 hours; ③ intravenous injection: continuous intravenous drip method and intermittent intravenous injection method, can be 50mg each time, 1 injection every 4-6 hours.
When heparin is applied, the clotting time needs to be measured to adjust the heparin dose. It is generally measured by the test tube method, 1 hour before the interval injection to adjust the next injection dose, and the normal value of clotting time (test tube method) is 4 to 12 minutes. During heparin therapy, the clotting time is required to be maintained at 15 to 20 minutes. If the clotting time is 20-25 minutes, the heparin dose is halved; if the clotting time exceeds 25 minutes, the injection is suspended once. 4-6 hours later, the dose is measured again to determine the heparin dosage. The course of heparin is usually 4 to 5 days, and then oral anticoagulants, such as coumarins, are applied.
Heparin generally has few allergic reactions. Excessive dosage can cause bleeding, such as hematuria, traumatic bleeding or visceral bleeding. Once it occurs, it can be antagonized by fisetin sulfate at a dose of 1 to 1.5 mg against heparin 1 mg. It has a complete antagonistic effect and can be injected every 4 hours until the bleeding stops. Fresh blood can be transfused if necessary.
Coumarin derivatives are a thrombinogen inhibitor. It has a long induction period and usually takes 24 to 48 hours after administration before it starts to work. The effect also takes a long time to disappear, and there is a cumulative effect of the drug, and it often takes 4-10 days to completely disappear after stopping the drug. Coumarin derivatives are administered orally. The prothrombin value should be maintained at 20-30% (concentration %).
Now the domestic common coumarin derivatives are: double coumarin (dicoumarin), new anticoagulation (stntrom) and warfarin sodium (warfarin sodium). Warfarin sodium is generally the most commonly used, with 5 mg 3 times daily on the first day, 5 mg twice daily on the second day, and 2.5 mg or 5 mg once daily starting on the third day, adjusted according to the prothrombin time.
In case of bleeding caused by coumarin derivatives, the treatment is intravenous vitamin K110-20 mg. For severe bleeding, high-dose intravenous vitamin K1, 50 mg each time, 1 to 2 times daily, and fresh blood transfusion is required.
Where liver and kidney insufficiency and bleeding tendency, anti-coagulant therapy is prohibited. In 1975, Hirsh pointed out that it takes 4-6 weeks for calf deep vein thrombosis; 3-6 months for iliofemoral vein thrombosis; 4-6 weeks for mild pulmonary embolism; and 6 months for severe pulmonary embolism.
3.Thrombolytic therapy
Acute deep vein thrombosis or pulmonary embolism can be treated with fibrinolytic agents including streptokinase and urokinase in patients within 1 week of onset. 1984 Zimmermann advocated that thrombolytic drugs can still be applied within 2 weeks of thrombosis.
Streptokinase is produced from Streptococcus haemolyticus cultures and urokinase is produced from human urine, both of which are effective activators that activate fibrinogen in the blood to convert it into fibrinase. This enzyme can hydrolyze fibrin into small molecule polypeptides to dissolve blood clots.
The method of using urokinase: ① initial dose: generally 50,000μ/time, dissolved in 5% glucose water or low molecular dextrose 250-500ml intravenous drip, twice a day; ② maintenance dose: the normal value of fibrinogen is 200-400ml/dl, if the measurement is lower than 200mg/dl, suspend the injection once. Also determine the euglobulin dissolution time, the normal value is greater than 120 minutes, such as less than 70 minutes, also need to suspend the time. The use of time can be up to 7-10 days; ③ side effects: urokinase is not pyrogenic, side effects are far lighter than streptokinase, there may be bleeding such as wound bleeding, but rarely occurs, fever, nausea, vomiting, headache, lethargy, chest tightness and rash, etc.. In case of serious bleeding, 10-20 ml of 10% 6-amino acid can be administered intravenously, and fibrinogen can be infused if necessary.
In recent years, new thrombolytic drugs that are limited to the thrombus site have been successfully developed, adding a new page to the history of thrombolytic drugs. In 1989, Krupski reported that the clinical application of TPA in the treatment of vascular obstruction had resulted in the complete dissolution of the thrombus in 7 out of 8 cases and the dissolution of the thrombus in 1 out of 8 cases. 7 cases of complete dissolution of thrombus, 1 case of partial dissolution, no complications. Domestic experimental research has been completed, but it has not been put into clinical application. Urokinase precursor (Pro-UK), which is the live action of urokinase, is in the experimental stage both at home and abroad.
4.Other drugs
Medium molecular weight (average molecular weight 70,000~80,000) or low molecular weight (average molecular weight 20,000~40,000) dextran intravenous drip is an adjuvant drug for the treatment of acute deep vein thrombosis, which is now widely used. Low-molecular dextran can eliminate red blood cell coagulation, prevent the thrombus from continuing to grow and improve microcirculation. The duration of treatment is 10-14 days. It can be applied simultaneously with heparin or urokinase. Side effects: Occasional allergic reactions, chest tightness, dyspnea, back pain, bleeding and chills, etc.
II: Surgical treatment
Deep vein thrombosis of the lower limbs is usually not surgically removed. However, for extensive iliofemoral vein thrombosis with arterial blood supply obstruction and the limb tends to gangrene (femoral cyanosis), surgical removal of embolus is often required. The operation time of iliofemoral vein thrombosis removal is usually within 72 hours of the onset of thrombosis, especially within 48 hours of the best results. The earlier the surgery, the less the thrombus adheres to the vein wall, the lighter the inflammatory response, the lighter the destruction of the vein lining, the less the secondary thrombosis, the more complete the surgical removal of the thrombus and the better the postoperative outcome.
In the case of iliofemoral vein dissection, the inferior vena cava or the common iliac vein should be temporarily blocked to prevent pulmonary embolism when the thrombus is dislodged during embolization. If the inferior vena cava is exposed by entering the abdominal route and blocked by clamping, it is more invasive and time-consuming. The current method is to make a small incision in the inguinal region of the healthy side under local anesthesia to expose the femoral vein and insert a vena cava blocking catheter with a balloon to temporarily block the inferior vena cava reflux during embolization. Then a femoral incision is made on the diseased side to expose the femoral vein, and a Fogarty catheter (a catheter with a balloon) is inserted proximally to the common iliac vein, where the balloon is inflated and the thrombus is slowly pulled out.
Atrophy of the vena cava blocks the balloon of the ground tube and restores venous blood return. A plastic band is used to temporarily control the proximal femoral vein, the Fogarty catheter is then inserted distally into the N vein, and after bulging the balloon, the distal thrombus is slowly pulled out. This can be supplemented by repeated manual compression on the body surface in a centripetal direction to squeeze out the thrombus within the calf vein and branches. This is an essential step, as secondary thrombosis can otherwise occur. The venous wall incisions on both sides should be closed with fine interrupted or continuous sutures with 7-0 or 5-0 nylon threads, requiring neat inner membrane alignment and no inversion of the outer membrane. Postoperative anticoagulation therapy is required.
Andriopulos reported 164 cases of iliac vein thrombectomy, 87 of which were operated within 4 days of onset, 41 within 8 days of onset, and the rest much later. There were 6 cases of pulmonary embolism and 2 deaths. Of the 165 cases, 134 were followed up longitudinally, and the best outcome was in patients operated within 1-4 days of onset. 50% of the 134 cases healed, 295 occasionally had moderate swelling, and only 4 cases had severe post-thrombotic syndrome. In 1980, Nüllen reported 46 cases of acute iliofemoral vein thrombosis, and prompt thrombectomy was performed in 13 of these patients with pulmonary embolism. The thrombosis and pulmonary embolism did not occur in any of the 13 patients, and all patients had preserved venous valve function and no symptoms of post-deep vein thrombosis syndrome. The iliofemoral vein thrombectomy is still one of the effective treatment methods if the indications for surgery are mastered.