Some patients had a successful surgery, but suddenly died a few days after the surgery when they got out of bed. It turns out that the patient had a deep vein thrombosis after the surgery and died due to pulmonary embolism caused by the dislodged thrombus. Once it happens, there is no special treatment.
Deep vein thrombosis of the lower extremity has manifestations
Swelling of the affected limb
This is the most common symptom of lower extremity venous thrombosis, with high tissue tone and non-sunken edema. The skin is red and the skin temperature is higher than that of the healthy side. In case of severe swelling, blisters may appear on the skin. The site of swelling varies with the site of thrombosis. In patients with iliac-femoral vein thrombosis, swelling of the entire affected limb is obvious, while in patients with calf plexus thrombosis, swelling is limited to the calf; in patients with inferior vena cava thrombosis, swelling occurs in both lower limbs. If the thrombosis starts in the iliac-femoral vein, the swelling of the thighs appears early. If the thrombus starts in the calf plexus and gradually extends to the iliac-femoral vein, the swelling of the calf appears first and then the thigh is involved. The swelling is most severe on the second or third day after the onset of the disease and then gradually decreases. The decrease in swelling is characterized by a decrease in tissue tone and then by a gradual decrease in the circumference of the affected limb, but it is difficult to change to normal unless the thrombus is completely removed early. In the later stages of thrombosis, although some of the veins have been recanalized, the venous pressure in the affected limb is still high because the venous valve function has been disrupted, and the presentation is similar to that of primary lower limb valve insufficiency.
Pain and pressure pain
The causes of pain are mainly 2-fold.
1.The thrombus causes inflammatory reaction in the vein, which causes persistent local pain in the affected limb.
2. The thrombus blocks the vein, causing obstruction of venous return in the lower extremity, resulting in swelling and pain in the affected limb, which is aggravated when standing upright. The pressure pain is mainly confined to the area where the venous thrombus produces inflammatory reaction, such as the femoral vein path or calf. Calf gastrocnemius pressure pain is also known as positive Homans sign. Since there is a risk of dislodging the thrombus by squeezing the calf, excessive force should not be applied during the examination.
Superficial varicose veins Superficial varicose veins are compensatory reactions, when the main veins are blocked, the venous blood of the lower extremity returns through the superficial veins and the superficial veins expand compensatively. Therefore, superficial varicose veins are usually not obvious in the acute phase and are a manifestation of the sequelae of venous thrombosis in the lower extremities.
Femoral cyanosis When DVT of the lower extremity extensively involves the intramuscular venous plexus, the iliofemoral vein and its lateral branches are all obstructed by the thrombus and the tissue tension is extremely increased, resulting in arterial spasm of the lower extremity and limb ischemia or even necrosis. Clinically, the pain is severe, the skin of the affected limb is shiny with blisters or blood blisters, and the skin color is blue-purple, called painful femoral cyanosis (Phlegmasia Cerulea Dolens). It is often accompanied by arterial spasm, weakened or absent arterial pulsations in the lower extremities, decreased skin temperature, and consequently, a high degree of circulatory disturbance. The patient has a strong systemic reaction with hyperthermia and atrophy, and is prone to shock manifestations and wet gangrene of the lower extremities.
Femoral leukodystrophy In acute embolism of the deep veins of the lower extremities, the edema of the lower extremities reaches its highest level within a few hours, the swelling is concave and hypertonic, and the obstruction occurs mainly in the femoral venous system. When combined with infection, the artery is stimulated to persist in spasm and swelling of the whole limb, pale skin and small subcutaneous reticular dilatation of the veins is seen, called painful femoral bruising (Phlegmasia Alba Dolens).
Femoral cyanosis and femoral leukodystrophy are less common and are an emergency condition requiring urgent surgical removal of the embolus in order to save the affected limb.
History When a patient has sudden swelling of one lower extremity, the possibility of deep vein thrombosis in the lower extremity should be considered. Take a detailed history to find out whether there are any predisposing factors for deep vein thrombosis, such as history of recent surgery, history of trauma, history of infection in the lower extremity, prolonged bed rest in women after delivery, and malignancy.
Evaluation of embolic plane The upper boundary of venous thrombosis is estimated according to the plane signs of limb swelling.
1, edema below the middle of the calf for N vein.
2, edema below the knee for the superficial femoral vein.
3, edema below the mid-thigh for the common femoral vein.
4, edema below the buttocks for the common iliac vein.
5.Bilateral lower extremity edema as inferior vena cava.
Evaluation of disease course
(1) Whole limb lesion: It is a long natural evolutionary process.
1.Type I: The course of the disease is within 3 years, of which 86% are within 1 year.
2.Type IIA: 67% of those with a disease duration of 1 to 10 years.
3.Type IIB: The disease duration of 5 to 20 years accounted for 75%.
4.Type III: 91% of those with a disease duration of 15 years or more.
(2) Focal segment lesion: the more proximal the lesion, the more delayed the recanalization. 1.The duration of occlusion of iliac and iliac-femoral segment is more than 15 years, accounting for 63%. 2.The duration of occlusion of superficial femoral vein and its distal segment is less than 3 years, accounting for 70%.
Diagnosis
1.Most often seen in postpartum, post-pelvic surgery, trauma, advanced cancer, coma or long-term bedridden patients.
2.The onset of the disease is acute, 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. If the thrombus extends to 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.
3.Mixed type. There is both blood backflow and return obstruction.
5.Thrombus dislodgement can lead to pulmonary embolism.
6.Radiofibrinogen test, Doppler ultrasound and venous flow mapping can help to diagnose. Venography can confirm the diagnosis.
Treatment measures
(A) Acute phase In recent years, the acute phase treatment of deep vein thrombosis is mainly non-surgical, but occasionally surgical treatment is still needed.
1.Non-surgical treatment
(1) Bed rest and elevation of the affected limb: 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 exerting force to prevent the thrombus from dislodging and 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 return flow and maintain the minimum venous pressure to stop the development of lower limb edema.
Elastic stocking use time.
1.For thrombophlebitis of the deep or superficial veins of the calf, it is generally not necessary, but if edema appears in the ankle and lower calf, it can be used for several weeks.
2, to N, femoral vein thrombosis, generally use no more than 6 weeks.
3.For iliofemoral vein thrombosis, it is used for 3 months first, and then removed intermittently, generally not more than 6 months, but if edema appears, it is necessary to continue to apply. Patients in the early stage, it is forbidden to stand and sit for a long time. For patients with heavy iliofemoral vein thrombosis, appropriate restriction of standing and sitting position and elevation of the affected limb for 3 months can promote the establishment of collateral veins in the lower limbs to reduce lower limb edema.
(2) Anticoagulant therapy: This is the most important modern treatment for deep vein thrombosis. The correct use of anticoagulants can reduce the complication rate of F embolism and the sequelae of DVT. Its role is to prevent the formed thrombus to continue to grow and the formation of new thrombus in other parts, and to promote the thrombosed vein to be retubulated more rapidly.
Indications.
1, within 1 month after the formation of 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 are 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 as 1~1.5mg/dkg/4~6h.
Route of administration can be injected via subcutaneous fat layer, intramuscular, or intravenous.
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 of body weight each time. 1 injection every 8 to 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 injected 50mg each time, once every 4-6 hours.
Heparin application, the coagulation 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, it is measured again to determine the heparin dosage. The course of heparin is usually 4 to 5 days, and then oral anticoagulant drugs, 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 %). Coumarin derivatives are now commonly used in China: dicoumarin, new anticoagulation (stntrom) and warfarin sodium (warfarinsodium). Warfarin sodium is most commonly used, 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 from 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 are 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 deep vein thrombosis in calf; 3-6 months for iliofemoral vein thrombosis; 4-6 weeks for mild pulmonary embolism; 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 peptides to achieve the purpose of dissolving blood clots.
The use of urokinase method.
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: normal value of fibrinogen is 200-400ml/dl, if the measurement is lower than 200mg/dl, suspend the injection for 1 time. 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. Use for up to 7 to 10 days.
3.Side effects: Urokinase has no pyrogenic reaction, and the side effects are far lighter than streptokinase. There may be bleeding such as wound bleeding, but it 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 have been successfully developed which are limited to the thrombus site, adding a new page to the history of thrombolytic drugs.
1, human tissue-type fibrinogen activator (TPA), extracted from uterine tissue or human melanoma cell culture, can specifically activate the fibrinogen on the surface of thrombus gel state, but has no effect on the fibrinogen in the dissolved state of blood circulation, so there is no systemic effect. There were 7 cases of complete dissolution of thrombus and 1 case of partial dissolution without complications. Domestic experimental research has been completed, but it has not been put into clinical application.
(2) Urokinase precursor (Pro-UK), which is the active role of urokinase, is in the experimental stage both at home and abroad.
(4) Other drugs: medium molecular weight (average molecular weight of 70-80 thousand) or low molecular weight (average molecular weight of 20-40 thousand) dextran intravenous drip, is an adjuvant drug for the treatment of acute deep vein thrombosis, and 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.
2.Surgical therapy for deep vein thrombosis of lower limbs, generally not for surgery to remove the embolism. However, for extensive iliofemoral vein thrombosis with arterial blood supply obstruction and the limb tends to gangrene (femoral cyanosis), surgery is often required to remove the embolus. The operation time of iliofemoral vein thrombosis removal is usually within 72 hours of the opening of the door, especially the best result is within 48 hours. 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 on 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. The femoral vein is then exposed through an incision in the groin on the diseased side, 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 vein 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. Within one year of the onset of chronic phase lower limb deep vein thrombosis, generally no venous reconstruction should be performed. During this period, a large amount of collateral circulation can be expected to be established. After medication and other adjuvant treatments, the lower extremity venous reflux disorder can be significantly reduced in many cases.