1.What is venous thrombosis?
In layman’s terms, a venous thrombosis is a “blockage” of the flowing blood, which blocks a blood vessel. The thrombosis can occur in superficial veins, also can block deep veins, and may even occur in visceral venous system such as mesenteric veins. While superficial venous thrombosis often has few serious clinical consequences, deep vein thrombosis in the lower extremities can cause pulmonary infarction and lead to the patient’s death. When we talk about “venous thrombosis”, we generally refer to the deep vein thrombosis of lower limbs.
2.How is venous thrombosis formed?
The formation factors of venous thrombosis are relatively complex, but it is generally believed that venous blood flow stagnation, vascular injury and blood hypercoagulation are the three main factors. Stagnant blood flow refers to slow blood flow, which often occurs in patients who are bedridden for a long time (stroke, fracture, after major surgery) or sitting for a long time (surfing the Internet, playing mahjong, long car rides, etc.). The same is true of “running water does not rot and the household pivot does not get worm-eaten”. When a blood vessel is damaged, the structure of the vessel wall changes, causing a clotting reaction. Likewise, the change of blood composition, which puts the blood in a state of easy coagulation, can lead to thrombosis under the inducement of certain factors.
3.What is deep vein thrombosis in lower limbs?
There are three venous systems in the lower limbs, one is the superficial venous system, the other is the deep venous system, and the third is the traffic branch venous system connecting the superficial and deep veins. Under normal circumstances, blood from superficial veins flows back to the heart through the traffic branch veins or directly to the deep veins. When the thrombosis occurs in the deep vein system, it is called deep vein thrombosis (DVT) of the lower extremities.
4.Why are patients prone to DVT after surgery?
Clinical research shows that surgery increases the viscosity of the patient’s blood, coupled with limited postoperative activity and slow blood flow to the lower extremities, the incidence of thrombosis is greatly increased. The incidence of lower extremity DVT is especially high after orthopedic surgery, obstetrical and gynecological surgery, neurosurgery, and general surgery, but the current rate of misdiagnosis and omission is still high, and it is often overlooked in the early stage.
5.Does lower extremity deep vein thrombosis run in families?
So far, no research has shown that lower extremity deep vein thrombosis is hereditary.
6.Does smoking and drinking cause deep vein thrombosis?
Smoking alone does not directly cause DVT. However, smoking can lead to increased blood clotting and vascular spasm, which, together with other factors, can easily trigger the formation of deep vein thrombosis. Therefore, for patients who have already suffered from DVT, we ask them to stop smoking. Drinking alcohol does not cause deep vein thrombosis, but the alcohol content will cause arterial dilation, and deep vein thrombosis is a reflux obstacle, and drinking causes the blood of lower limbs to “enter more and return less”, which can increase the burden of lower limb veins. Therefore, for patients with deep vein thrombosis, we also do not advocate their drinking.
7.Does the diet of patients with deep vein thrombosis have any special requirements?
The diet of patients with deep vein thrombosis should not be strictly restricted, but a general principle is that the diet of patients with deep vein thrombosis should be low in sugar, salt and fat. For example, animal offal is high in cholesterol, which can easily lead to “hyperlipidemia” in the long term, and elevated blood lipid is also a factor that increases blood viscosity.
8.Why are trauma patients prone to deep vein thrombosis?
Traumatic injury, especially when accompanied by vascular injury, can easily lead to deep vein thrombosis due to the damage of venous intima, which induces platelet aggregation locally, and the reduction of activity after trauma.
9.I have diabetes and hypertension, do I need to pay special attention to prevent deep vein thrombosis?
Yes. Patients with diabetes and hypertension tend to be older and have hyperlipidemia, high blood coagulation, and arteriosclerosis, which makes local blood flow poor and makes deep vein thrombosis easy to form. Therefore, patients need to actively control blood sugar and blood pressure level before major surgery to reduce postoperative complications such as deep vein thrombosis, etc. Oral enteral aspirin tablets or use of anticoagulants such as heparin after surgery can prevent deep vein thrombosis.
10.Why do the lower limbs of patients with deep vein thrombosis swell?
As mentioned before, the venous reflux of the lower limbs is mainly through the deep veins. Once deep vein thrombosis occurs in the lower limbs, the lower limbs have impaired return flow and the superficial venous system cannot fully compensate for it, so arterial blood still enters continuously, causing high pressure and vasodilatation in the lower part of the thrombus, which makes part of the plasma components leak into the tissue interstices and cause edema in the lower limbs.
11.I have had deep vein thrombosis for almost a month, and now I have some bruises on my calf, what is it?
When the deep vein is blocked, a large amount of venous blood can only return through the superficial vein, which will compensate for the expansion of the superficial vein, and the pressure in the superficial vein will also increase, so many patients will gradually appear dilated veins on their legs, i.e. “bulging veins”.
12.I had deep vein thrombosis five years ago, and this year I started to have ulcers on my calves.
Yes, the two are related. After deep vein thrombosis occurs, if left untreated, the thrombus attached to the venous valve will be mechanized, and over time, the thrombus will be gradually fibrotic and absorbed by the body, while the function of the valve will be irreversibly lost. Venous reflux disorder combined with blood backflow can cause local blood stagnation in the lower extremities, local skin nutrient deficiency, when a minor trauma can cause skin ulceration for a long time. In clinical practice, this is also one of the manifestations of thrombotic sequelae.
13.My calf is black and the doctor diagnosed it as the sequelae of deep vein thrombosis. What is the sequelae of deep vein thrombosis?
After the formation of deep vein thrombosis, part of the thrombus is mechanized and absorbed, which destroys the function of the valve and makes the blood flow backward, and part of the thrombus is mechanized and causes the blockage or narrowing of the venous lumen, both of which result in the increase of pressure in the venous system of lower limbs, which is clinically manifested as lower limb edema, superficial varicose veins, skin pigmentation and even ulcers. This series of manifestations is called the sequelae of deep vein thrombosis.
14.The temperature of my left leg with deep vein thrombosis seems to be higher all the time, and it feels hot, why?
After the occurrence of deep vein thrombosis, due to the increase of venous pressure in the lower limbs, the superficial veins expand and blood flow increases, which will lead to the increase of skin temperature of the whole lower limbs. It is easy to understand that some patients can feel the skin “hot”.
15.My left leg is swollen and painful, the local doctor said I have “fire”, and another doctor said it’s “Dantoise”, but the vascular surgeon diagnosed me with deep vein thrombosis, how to distinguish these three diseases?
The so-called “fire flow” refers to superficial venous thrombosis, which is a red line on the skin, with localized palpable striated veins and pressure pain. The term “Danemia” refers to an acute lymphatic infection with localized flushing of the skin, often accompanied by chills and high fever. Deep vein thrombosis is a swelling of tissue caused by venous hypertension due to intravenous thrombosis, so the swelling is widespread and uniform, with no local skin tenderness, but the deep calf muscles have tenderness in the acute phase. These three diseases are easily confused clinically, but it is not difficult for professional vascular surgeons to identify them.
16.I had deep vein thrombosis and improved after hospitalization, but it has been one month since I was discharged, why do I still have calf edema?
The best time to treat deep vein thrombosis is within 72 hours after the onset of thrombosis. After this time, the thrombus will be partially mechanized, and the effect of thrombolysis and clot retrieval will be greatly reduced. Therefore, many patients come to the hospital with a long course of disease. Through anticoagulation therapy, the edema of lower limbs will be improved significantly, but it takes a long time to completely subside, some even up to several years. Therefore, early treatment is very critical.
17.My calf is particularly swollen, but ultrasound suggests that there is blood clot at the root of my thigh, while my thigh is not so swollen, what is the reasoning?
A. No matter which part of the lower limb is thrombosed, it causes venous reflux obstruction and pressure increase, and the lower the position of the human body in the upright state, the higher the pressure of the veins, so the swelling is often more obvious in the lower leg. For deep vein thrombosis, the iliac, femoral, N, and gastrocnemius veins should be routinely checked throughout.
18.I have lower extremity deep vein thrombosis, will it lead to amputation?
Generally, lower extremity DVT will not lead to amputation, but there is one exception, which is “femoral bruise”. The so-called “femoral cyanosis” refers to the widespread thrombosis of the deep vein in the lower extremity, which causes the artery to spasm, coupled with tissue edema and elevated pressure resulting in local ischemia and hypoxia, clinically manifested as severe swelling of the lower extremity, skin bruising, blistering and even gangrene.
19.Is deep vein thrombosis life-threatening?
Yes. The most serious complication of deep vein thrombosis is pulmonary embolism. Once the venous thrombus is dislodged, it will travel upward with the blood flow, pass through the heart, reach and block the pulmonary artery, causing pulmonary infarction. Clinically, mild patients present with transient chest tightness and shortness of breath, while severe patients have sudden onset of extreme dyspnea and palpitations, and can die within minutes due to respiratory failure.
20.My mother has deep vein thrombosis, I have been worried whether she will have pulmonary embolism, will all patients with deep vein formation have pulmonary infarction?
No, clinically critical pulmonary infarction is still uncommon, from our experience it is about 5% or less. The following cases require special attention.
(1) Patients with bleeding tendency during anticoagulation therapy (e.g., long-term oral glucocorticoid users, hypertensive patients at risk of cerebral hemorrhage)
(2) Patients with clinical signs of pulmonary embolism
(3) Patients with recurrent venous thrombosis during anticoagulation (poor anticoagulation)
In addition, there is a greater chance of pulmonary embolism in the acute stage, once the thrombus is mechanized, the chance of thrombus dislodgement is greatly reduced, therefore, excessive worry is also unnecessary, the key is to actively treat early.
21.I am in the vascular surgery department because of deep vein thrombosis, and there are several patients with the same disease in the ward, and they have the same left leg as me.
This is not a coincidence, more than 70% of the clinical DVT occurs in the left lower limb. This is mainly due to two anatomical factors. One is that the right iliac artery just crosses the left iliac vein, which is easy to cause compression, and the other is that the angle between the left iliac vein and the inferior vena cava is larger, and the local blood return is poorer. Therefore, deep vein thrombosis should be considered when clinically encountering sudden unexplained edema of the left lower extremity.
22.My uncle suffered from deep vein thrombosis, because of the lack of timely treatment now he has the sequelae of lower limb venous thrombosis and skin ulceration.
The sequelae of lower limb vein thrombosis can be clinically divided into three types: complete recanalization, partial recanalization and occlusion. The fully recanalized type can be treated by surgery, while the latter two types of surgery are less effective and are mainly treated by drugs plus air pump physiotherapy. All patients should take long-term oral aspirin and wear antithrombotic stockings. The treatment of the sequelae of deep vein thrombosis is long-term, and patients need to have some confidence and patience, otherwise, the condition will easily deteriorate.
23.I have deep vein thrombosis, why don’t the doctors take out the thrombus by surgery?
In recent years, with the emergence of new thrombolytic and anticoagulant drugs and the high recurrence rate of thrombosis after surgery, many physicians prefer non-surgical treatment. However, if the onset of the disease is within 72 hours and “bruising of the femur” occurs, thrombectomy may be necessary. In addition, a mechanized thrombus cannot be removed, just as a hardened cement attached to a wall will only damage the wall if it is removed.
24.How can pulmonary embolism be prevented?
Currently, the best way to prevent pulmonary embolism is to place a filter in the inferior vena cava. This way, if a blood clot falls out, it will be stopped by the filter in the vessel and will not pose a threat to life. The clot on the filter will be gradually absorbed.
25.I had a pulmonary embolism this year, and I was saved by a vascular surgeon, who placed a filter in my inferior vena cava to prevent another embolism.
The placement of a filter is relatively simple for a vascular surgeon. A thin catheter is placed in the femoral vein through a puncture at the base of the thigh, and then the filter is fed through the catheter into a specific inferior vena cava site in the body, where it opens automatically like an umbrella and is supported on the vessel after release.
25.I had an inferior vena cava filter placed last year and I have had no discomfort for a year, but I am always concerned about the effects of the filter being in my body later.
Generally, no. The inferior vena cava filter is made of titanium alloy, which has almost no effect on human blood and has minimal tissue reaction, and can be placed in the body for the rest of its life, just like the artificial heart valve and the artificial femoral fist woad material. Tens of thousands of filters are placed worldwide each year, but few complications have been reported, mainly local hematoma, arteriovenous fistula, filter displacement, recurrent pulmonary embolism, etc. Therefore, it is not necessary to worry too much, but only regular annual review is required.
26.Is it complicated to place the inferior vena cava filter? Is it a very risky procedure? Do I need general anesthesia?
The placement of the inferior vena cava filter requires only local anesthesia. The procedure itself is not very risky and the operation is not complicated. However, other risks arise because the patient often has other underlying diseases (e.g., hypertension, diabetes, etc.). The common complications of filter placement are local puncture port hematoma and arteriovenous fistula, which can now be completely avoided by the latest technology used in our vascular surgery department.
27.Why do I need to wear antithrombotic stockings for a long time for the sequelae of deep vein thrombosis?
It should be said that the ideal treatment is.
(1) regular blood air pump therapy.
(2) Wearing antithrombotic stockings.
(3) oral anticoagulants.
However, air pump therapy is not widely available to patients due to various conditions, so wearing antithrombotic stockings is especially important. The pressure distribution of a proper antithrombotic stocking should be decreasing from bottom to top, and the pressure at the ankle should be above 20 mmHg.
28.My grandfather has deep vein thrombosis, and blood tests are often taken during his hospitalization and regularly after his discharge, is this necessary?
It is very necessary. The most common treatment for DVT is anticoagulant medication, and the main side effect of anticoagulant medication is bleeding, and there are individual differences in the effect of anticoagulant medication. The blood test is to see whether the blood index is qualified after anticoagulation, otherwise the index is too low, the anticoagulation is ineffective; if the index is too high, it is easy to bleed. Therefore, the blood index is used to adjust the drug dose to achieve the purpose of both effective anticoagulation and reducing the risk of bleeding. The anticoagulant should be taken orally for 3-6 months after discharge from the hospital, and regular laboratory tests are also needed to adjust the dose.
29.I have deep vein thrombosis, why should I be given 24-hour continuous hookup therapy?
24-hour continuous intravenous infusion of heparin for deep vein thrombosis is a common standard of care internationally. Its advantage is that it keeps the blood concentration at a constant level, avoids the ups and downs of anticoagulation, and reduces bleeding complications. However, it also has the disadvantage that the patient’s activity is somewhat restricted. But weighing the pros and cons, such treatment should be acceptable.
30.My loved one received thrombolytic treatment for deep vein thrombosis at the local hospital last month.
Urokinase, streptokinase and tissue fibrinogen complex (tPA) are commonly used as thrombolytic drugs. Streptokinase has better thrombolytic effect and less bleeding complications, but some patients may have tissue reactions, manifested as high fever and chills, which usually do not affect life safety. Currently, recombinant streptokinase is available in the market, and the tissue reaction is greatly reduced, but some patients still have high fever, but it can generally subside after two or three days.
31.Why do I have to take oral warfarin for 3-6 months after hospitalization?
Studies have shown that the probability of recurrent thrombosis is relatively high within 3-6 months after acute deep vein thrombosis. Therefore, the use of continuous anticoagulants is especially important during this period.
32.Why don’t you just take oral anticoagulant drugs, isn’t it convenient?
Oral anticoagulant drugs such as Warfarin are slow to take effect, and it usually takes 72 hours to reach peak blood concentration. Therefore, for acute deep vein thrombosis, intravenous injection can achieve anticoagulation effect quickly, and then discontinue intravenous drugs after oral drugs reach concentration.
33.My arm is red and painful after intravenous injection, does it matter?
Some of the injected drugs can induce superficial venous inflammation, often forming local thrombosis, which is clinically manifested as a hard lump of strips, and the surrounding skin is flushed with pressure pain, which is generally harmless to human body and can be relieved by local hot compresses and oral aspirin.
34.My father was diagnosed with “saphenous vein thrombosis” in the hospital, does it matter?
The thrombosis confined to the saphenous vein is often caused by varicose veins, which has no serious consequences to human body except for clinical symptoms such as redness, swelling and pain, but if the thrombosis spreads to the deep vein through the traffic branch or directly, it will cause serious consequences. Therefore, early surgical treatment is necessary for severe superficial venous trunk thrombosis