In life, many middle-aged and elderly people complain about the increasing weakness of their legs, which used to walk a few miles without problems, but now they feel sore and painful after walking a hundred or eighty meters. Usually, they also feel cold legs and feet, and they have to wear thick socks to keep warm at home and even when they sleep. Many people think that this is a natural phenomenon of aging and do not give due attention to it. In fact, this soreness often indicates a potential disease – lower limb atherosclerosis occlusive disease. This disease is characterized by an insidious onset in the early stages, but once it reaches the middle and late stages, it will cause severe pain and even necrosis in the affected limbs due to severe ischemia, and a considerable number of patients have to undergo amputation, thus seriously affecting the quality of life. 1.What is lower extremity atherosclerosis occlusive disease? Simply put, lower extremity atherosclerosis is a disease in which the arteries in the lower extremities are severely sclerotic and the arterial lumen is narrowed or even occluded, resulting in a lack of blood supply to the lower extremities because the blood supplying nutrients to the extremities cannot reach the extremities smoothly through the arterial system. Depending on the degree of arterial disease in the lower extremities, patients may exhibit different symptoms. In the early stage of the disease, the ischemia of the lower extremity is not heavy, and the blood supply can basically meet the patient’s needs in a quiet state, and the patient may not feel anything. When the patient exercises, the amount of blood needed in the lower limbs increases greatly, but due to the narrowing or occlusive lesions in the arteries of the lower limbs, the blood cannot meet the needs of the body, and the muscles cannot get the oxygen supply and nutrients needed for exercise in time, so the muscles start anaerobic metabolism, and the increase of acidic metabolic waste causes the patients to feel soreness and pain in the lower limbs. The symptoms can be relieved by resting the muscles for a period of time and returning to a quiet state, but similar symptoms will still occur when exercising again. This is medically known as intermittent claudication and is a typical symptom of lower extremity atherosclerotic occlusive disease. When the ischemia of the lower extremity continues to worsen and the blood supply cannot meet the needs of the extremity even in a quiet state, then pain in the lower extremity will occur. This pain is constant and intense, and it becomes more severe at night or when the temperature drops, as the blood supply is further reduced due to arterial constriction. Many patients have trouble sleeping and eating at night as a result, leading to a sharp decline in physical status and possibly inducing accidents such as heart attacks and brain hemorrhages. When the lower limb ischemia has become so severe that it affects the survival of the limb, gangrene and ulcers at the end of the limb will appear. This is the most severe state of lower extremity ischemia and indicates that tissue necrosis has developed in the lower extremity as seen by the naked eye. Tissue necrosis may be combined with infection, or produce a large number of toxins, increasing the burden on the liver and kidneys and other important organs, and in serious cases even cause the failure of important organs. 2.What kind of people are prone to lower extremity arteriosclerosis occlusive disease? The underlying pathological change of lower extremity arteriosclerosis occlusive disease is atherosclerosis, and the risk factors of atherosclerosis such as advanced age, hypertension, diabetes, and smoking are also the causative factors of lower extremity arteriosclerosis occlusive disease. With the improvement of people’s living standards and the aging of the population, the incidence of lower extremity arterial occlusive disease is increasing and needs to be taken seriously. Statistics show that 0.3% of men aged 40-50 years have new cases of lower extremity atherosclerotic occlusive disease each year, while this value increases to 1% for those aged 75 years or older. A population-based survey in Australia showed that the prevalence of lower extremity atherosclerotic occlusive disease in men aged 65-69 years was 10.6%, while the prevalence of lower extremity atherosclerotic occlusive disease in men aged 75-79 years was as high as 23.3%. A U.S. census showed that 20% of patients with symptomatic lower extremity atherosclerotic occlusive disease had combined diabetes, and that patients with combined diabetes were younger and progressed more rapidly than those without diabetes. A survey in the United States found that 80% of patients with lower extremity atherosclerotic occlusive disease smoked, and a large number of clinical practice has proved that quitting smoking can improve clinical symptoms and slow down the progression of the disease. In addition, hypertension, hyperlipidemia and obesity are also causative factors of lower extremity atherosclerosis occlusive disease. 3.What tests can detect this kind of lower extremity atherosclerosis occlusive disease? There is a simple method that can help us to initially determine whether there is a lesion in the arteries of the lower extremities at home. There is an artery at the back of the dorsum of the foot and the back of the ankle joint. Under normal circumstances, the artery can be felt with the fingers, but if it cannot be felt, it means that there may be problems with the arteries in the lower extremities. In order to understand the exact location and extent of the lesion, further tests are needed, including arterial Doppler ultrasound, angiography (DSA), CT angiography (CTA) and magnetic angiography (MRA). Each of these methods has its own advantages and disadvantages. Lower extremity arterial Doppler ultrasound has the advantages of being safe, non-invasive and inexpensive, and is the most important screening test that can initially identify vascular lesions. Angiography is the “gold standard” for the diagnosis of lower extremity atherosclerosis and occlusive disease. In addition to accurately showing the location and degree of narrowing or occlusion of the lower extremity atherosclerotic vessels, it can also dynamically respond to changes in hemodynamics. If arterial stenosis or occlusion is found during the examination, interventional treatment can be performed at the same time. Therefore, angiography is not only a diagnostic method, but also a treatment tool. CTA is a computerized reconstruction of arterial vessels on the basis of CT scan, which has the advantages of non-invasive and low radiation dosage compared with ordinary angiography. MRA is also a non-invasive vascular examination, which is easy to be accepted by patients without radiation damage, but its image clarity is relatively low and easy to expand the lesion, which limits the clinical application of lower extremity atherosclerosis occlusion. 4.How should lower extremity atherosclerosis occlusive disease be treated? (1) Treatment of etiology As we mentioned earlier, the etiology of lower extremity arterial occlusive disease is atherosclerosis. Therefore, first of all, we must start from the cause, strictly control blood pressure, blood sugar and blood lipids, strictly quit smoking and change bad habits. At the same time, patients should go to a vascular surgeon as soon as possible and start regular treatment including antiplatelet medication and other medications as soon as possible. (2) Walking exercise Walking exercise can promote the establishment of arterial collateral circulation in the lower limbs, which has a certain effect on the treatment and rehabilitation of peripheral vascular diseases, especially on the intermittent claudication caused by lower limb ischemia. At present, walking exercise has been widely used abroad in the treatment of ischemic intermittent claudication of the lower extremities, and its recommendation has been equivalent to surgery. Of course, this walking exercise is also required to achieve a certain exercise intensity, and it is generally believed that exercising until close to the maximum pain of the limb and then stopping the exercise can achieve a better exercise effect. If the maximum pain occurs within 30 minutes after the start of the exercise, it means that the intensity of the exercise is too large and should be reduced appropriately; if the maximum pain occurs only after 60 minutes after the start of the exercise, it means that the intensity of the exercise is too small and should be increased appropriately. At the end of each exercise should not stop suddenly, but gradually decelerate until it stops. The exercise should be started with the accompaniment of medical personnel or family members so that the exercise can be adjusted at any time to prevent accidents. Of course, if the patient’s lower limb ischemia is severe, and there is already obvious resting pain or even gangrene, then the walking exercise method is no longer applicable. (3) Surgical treatment Surgical treatment includes traditional surgery and minimally invasive intervention. Traditional bypass surgery, as the name suggests, is to connect the relatively normal arteries at both ends of the lesion through artificial vessels or autologous veins, like a bridge across the diseased vessel, through which blood can pass and bypass the diseased artery to restore the blood supply to the distal artery. The key to the success of this procedure is that the arteries at both ends of the bridge need to be relatively normal, or what is known medically as the “outflow” and “inflow” pathways must be open. Only when the “piers” are strong enough can the bridge pass safely. Therefore, patients with extensive lesions and poor outflow tract vascularity have relatively poor bypass surgery results. Interventional treatment. It only requires a small eye puncture in the skin to deliver the catheter, balloon and stent to the diseased artery, and then use the balloon to open the narrowed or occluded artery and place the stent if necessary to open the vessel. Interventional treatment is less invasive, faster recovery, and has incomparable advantages over traditional surgery, and is mainly used for relatively limited stenosis or occlusive lesions, while useful attempts have been made for the treatment of long stenosis or occlusive lesions. With the advancement of science and technology, improvement of materials and physicians’ skills, interventional treatment has developed rapidly, and many lesions that traditionally had to be operated on can now be resolved by interventional methods. In clinical work, we often see some patients with lower extremity atherosclerosis occlusive disease not correctly diagnosed and treated for a long time, and the lesions become increasingly aggravated and finally develop into limb pain, necrosis, and finally have to amputate, which seriously affects the quality of life. The grim reality makes us vascular surgeons have the responsibility to remind people, especially middle-aged and elderly friends, to pay attention to lower limb atherosclerosis occlusive disease, to achieve early detection, early treatment, in order to avoid irreparable damage.