Lower limb deep vein thrombosis

　　The causes of lower limb deep vein thrombosis include venous blood stasis and hypercoagulable state, which are the two main reasons. A single factor is not sufficient to cause the disease independently, and it is often the combined effect of two or three factors that lead to deep vein thrombosis. For example, the incidence of deep vein thrombosis after childbirth is high, which is due to the combined factors of placental abruption in the uterine cavity after childbirth, which can stop bleeding quickly in a short period of time without causing postpartum hemorrhage and is closely related to the hypercoagulable state of blood. During pregnancy, the placenta produces a large amount of estrogen, reaching its peak at term. The amount of estriol can increase to 1000 times that of non-pregnant times. Estrogen promotes the liver to produce various coagulation factors, and at the end of pregnancy, there is also a significant increase in fibrinogen in the body, causing the blood to be in a hypercoagulable state. After childbirth, lying in bed further leads to venous blood stasis in the lower limbs, thus increasing the tendency to develop deep vein thrombosis. Simple blood stasis is not enough to cause the disease, and sometimes it is accompanied by damage to the vascular wall, such as direct injury, chronic diseases, or distant tissue injury producing leukocyte chemotactic factors, causing leukocytes to move towards the vascular wall. Similarly, the formation of gaps in the endothelial cell layer and the exposure of subendothelial gel of the basement membrane can also cause platelets to move towards the vascular endothelium, leading to the occurrence of the coagulation process.

　　本病的并发症主要有以下几种：

　　1、肺栓塞  肺栓塞是指肺动脉或其分支被栓子阻塞所引起的一个病理过程。其诊断率低误诊率和病死率高。临床上预防肺栓塞多采用腔静脉滤器置入下腔。静脉滤器是一种金属丝制成的器械，通过特殊的输送装置放入下腔静脉，以拦截血流中较大血栓，避免随血流进入肺动脉，造成致死性肺栓塞。

　　2、出血  溶栓治疗中最主要的并发症是出血，特别应警惕胃肠道颅内出血，因此溶栓治疗前应检查血型血红蛋白血小板及凝血功能；药量的调整通常以凝血酶原时间(PT)和部分凝血酶原时间(APTT)，维持在正常值的2~2.5倍为宜。溶栓过程及溶栓后应密切观察病人有无出血倾向，有穿刺部位出血，可压迫止血严重的大出血应终止溶栓，并输血或血浆对症治疗。对于出血性并发症，应指导病人自我观察及预防，如牙龈出血鼻腔出血皮肤粘膜出血出现黑便等，嘱病人不用硬尖物剔牙挖鼻孔耳道，勿用力咳嗽以免引起咯血；选用软毛牙刷刷牙，动作轻柔，以免引起不必要的创伤；饮食宜清淡宜消化，以免食物损伤消化道，多次富含纤维素的食物，保持大便通畅。

　　3、血栓形成后综合征  是最常见最重要的并发症，在血栓的机化过程中静脉瓣膜遭受破坏，甚至消失或者黏附于管壁，导致继发性深静脉瓣膜功能不全，即静脉血栓形成后综合征。

　　下肢静脉血栓最常见的主要临床表现是一侧肢体的突然肿胀，患下肢静脉血栓形成，病人局部感疼痛，行走时加剧，轻者局部仅感沉重站立时症状，加重体检有以下几个特征：

     1、患肢肿胀：肿胀的发展程度须依据每天用卷带尺精确的测量并与健侧下肢对照粗细才可，靠单纯依靠肉眼观察是不可靠的，这一体征对确诊深静脉血栓具有较高的价值，小腿肿胀严重时常致组织张力增高；

     2、压痛：静脉血栓部位常有压痛，因此下肢应检查小腿肌肉腘窝内收肌管及腹股沟下方股静脉；

     3、Homans征：将足向背侧急剧弯曲时，可引起小腿肌肉深部疼痛，小腿深静脉血栓时，Homans征常为阳性。这是由于腓肠肌及比目鱼肌被动伸长时刺激小腿血全静脉而引起；

     4, Superficial varicosities:Deep venous obstruction can cause increased superficial venous pressure, and superficial varicose veins can occur 12 weeks after onset.

　　The methods to prevent lower limb venous thrombosis include physical methods and drug methods. The specific methods are as follows:

　　One, physical methods

　　In the past, physical methods used to prevent deep vein thrombosis included early mobilization, limb elevation, and wearing elastic stockings. However, research has found that the above methods have no preventive effect on deep vein thrombosis. Recently, progressive pneumatic pressure stockings have been used in neurosurgical patients, advocating early use, starting immediately after surgery, and continuing until full spontaneous activity. Wearing this stocking can increase 75% of venous return flow and reduce the incidence of deep vein thrombosis from 20% to 10%.

　　Two, drug methods

　　Drug methods include using drugs that can prevent the formation of blood clots: aspirin, dipyridamole (Persantin), etc., but the preventive effect is not certain.

　　1, Low-dose heparin: Its role in preventing thrombosis has been recognized, and it may act by inhibiting factor X to interrupt the endogenous and exogenous coagulation pathways. The concentration of heparin in serum (0.05～0.033) IU/ml can prevent the formation of prothrombinase, and the concentration of heparin (0.25～0.5) IU/ml can also destroy the formed prothrombinase, but it may increase the risk of bleeding.

　　2, Low molecular weight heparin: The half-life is longer, the risk of bleeding is reduced, and the bioavailability is higher.

　　3, Dextran 40: Can reduce the aggregation of red blood cells. It can be used intravenously with 100ml before surgery, 400ml during surgery, 500ml on the night after surgery, and another 500ml on the second day after surgery. The main adverse reactions are allergic reactions. However, when using dextran in patients with craniocerebral lesions accompanied by destruction of the blood-brain barrier, it can worsen intracranial hypertension and brain edema. Therefore, dextran should be used with caution in patients with craniocerebral trauma and intracranial tumors.

　　Common examination methods include:Cervical venous pressure examination is an auxiliary examination method used to check whether the venous vessels are normal. Impedance volume plethysmography examination is to use various volume plethysmography instruments, measure the degree of increase in the lower leg volume after the balloon band blocks the return flow of the femoral vein, and the rate of decrease in the lower leg volume after removing the blockage, thereby determining the patency of the lower extremity veins to determine whether there is venous thrombosis. Plasma tissue plasminogen activator antigen detection is to detect whether there is plasma tissue plasminogen activator antigen in the human body. It is used to diagnose the presence of diseases related to the activity of the fibrinolysis system. Plasma tissue plasminogen activator inhibitor antigen detection is to detect whether there is plasma tissue plasminogen activator inhibitor antigen in the human body. It is used to diagnose thrombotic diseases. Plasma tissue plasminogen activator inhibitor activity detection is to measure the activity of plasma tissue plasminogen activator inhibitor in the human body, and it is detected by chromogenic substrate method.

     Free protein S determination

　　Free S protein determination is a diagnostic method for diseases by measuring the content of free S protein in the human body. Free S protein is an α single-chain glycoprotein in serum with a molecular weight of 83kDa. The main regulatory effect of SP is to compete with the binding site of the unstable state of C5b-7 for the target cell membrane lipid, and lose the membrane binding activity of C5b-7 by forming a hydrophilic SPC5b-7 complex (abbreviated as S5b-7), thereby protecting the cells near the complement activation site from accidental attacks.

　　Histopathology: Fresh thrombi in large veins are usually mixed, and the length of thrombi usually stops at an effective branch of the blood vessel. After thrombosis, thrombolysis can occur, and fibroblasts can invade, forming new granulation tissue, further organization, and the formation of new blood vessels and recanalization. If there is hyperplasia of connective tissue and scar formation, the affected vein becomes a sclerotic cord-like lesion.

　　Patients with deep vein thrombosis of the lower extremities should consume diets rich in vitamins (celery, chive, coarse grains, beans), high in protein (meat, fish, dairy products), and high in calories (milk, cakes, eggs, sweets); eat more high-quality protein, such as milk, chicken and duck (preferably wild chickens), fish, eggs (the yolks should be eaten less), and soy products, and eat less pork, beef, and mutton, and prefer lean meat; eat more foods rich in vitamins, such as fresh fruits rich in vitamin C, tomatoes, hawthorn, etc.; eat more fiber-rich foods, such as celery, coarse grains, etc., to increase gastrointestinal motility and avoid constipation; eat more soy products, dairy products, and eggs rich in vitamin B6; green leafy vegetables, beans, etc., rich in vitamin E; it is suitable to drink hot milk or listen to light music to relax the brain and promote sleep; patients need a low-fat diet (prohibit the use of fatty meat, yolks, brain), and avoid eating spicy, sweet, and greasy foods; eat less or not eat animal fats and internal organs, such as fatty meat, fat intestines, stomach, because these foods contain a high amount of cholesterol and saturated fatty acids, which are easy to aggravate atherosclerosis.

　　The main treatment method in Western medicine is the HOT Oxygen Therapy Thrombolysis. This technology uses hyperbaric oxygen therapy based on the pathogenesis of thromboangiitis obliterans to effectively increase the oxygen content in plasma and tissues, promote the regeneration of new capillaries, promote the healing of ulcers, and can also reduce blood viscosity; with the auxiliary thrombolytic treatment through the femoral artery, it utilizes the direction of arterial blood flow to act on the small arteries and veins of the affected limb, and can also communicate with some arteriovenous shunts, effectively improving the local blood flow of diabetic foot, increasing tissue blood supply and oxygen supply, and can further improve nerve function, allowing the disease to be cured. Through the above comprehensive treatment, various problems such as nerve damage, ischemia, and hypoxia are solved, and the dormant tissue cells are activated and regenerated, achieving the purpose of nourishing nerves, nourishing blood, detoxifying and removing corruption, and then restoring the function of nerve perception, smooth blood flow of blood vessels, and achieving the purpose of nutrient supply, normal recovery of limb body function, and muscle healing.

　　"HOT Oxygen Therapy Thrombolysis" is a set of the latest international diagnostic and treatment system for vascular inflammation diseases, jointly developed by the International Clinical Medicine Peripheral Vascular Disease Research Center in 2009 and experts from the Guangzhou Logistics Department Hospital. It is a mature and reliable treatment method for vascular inflammation. This workstation includes the full set of diagnostic standards and treatment plans for vascular inflammation, highly recommended by the World Health Organization (WHO), and is hailed as the international standard for minimally invasive treatment of vascular inflammation.