Obliterating diseases of the lower extremities: causes, symptoms, diagnosis, treatment

At the heart of this group of diseases is atherosclerosis of the arteries of the lower limbs, causing ischemia. A moderate degree of disease can be asymptomatic or cause intermittent claudication.

In severe conditions, pain can occur in rest with atrophy of the skin, hair loss, cyanosis, ischemic ulcers and gangrene. The diagnosis is established anamnestically, with a physical examination and by measuring the shoulder-ankle index. Treatment of a moderate degree of the disease includes the exclusion of risk factors, exercise, antiplatelet drugs and cilostazol or pentoxifylline depending on the symptomatology. Heavy PAB usually becomes an indication for plastic surgery on vessels or surgical shunting, and sometimes for amputation. The prognosis is generally good in treatment, although mortality is relatively high, because this pathology is often combined with the defeat of coronary or cerebrovascular vascular arteries.

[1], [2], [3], [4], [5], [6]

What causes obliterating diseases of the lower extremities?

Obliterating diseases of the lower extremities (OZNA) are diagnosed in about 12% of people in the US, men are more likely to get sick. The risk factors are the same as for atherosclerosis: hypertension, dyslipidemia [high-density lipoprotein cholesterol (LDL), low-density lipoprotein cholesterol (HDL), smoking (including passive smoking), diabetes and hereditary predisposition to atherosclerosis . Obesity, male sex and high homocysteine content are also risk factors. Atherosclerosis is a systemic disease. 50-75% of patients with obliterating diseases of the lower extremities also have clinically significant coronary artery disease or cerebral vascular pathology. However, IHD can go unnoticed, because because of obliterating diseases of the lower limbs, patients can not tolerate the physical stress causing the attack of angina.

Symptoms of obliterating diseases of lower extremities

As a rule, obliterating diseases of the lower limbs cause intermittent claudication: an uneasy sensation, a muscle spasm, a feeling of discomfort or fatigue in the legs that occurs during walking and decreases at rest. Symptoms of lameness usually appear in the lower legs, but they may appear in the hips, buttocks, or (rarely) hands. Intermittent claudication is a manifestation of exercise-induced reversible ischemia, similar to angina pectoris. With the progression of obliterating diseases of the lower limbs, the distance that a patient can pass without developing symptoms may decrease, and patients with a severe course of the disease may experience pain during rest, which is evidence of irreversible ischemia. Pain in rest usually occurs in the distal parts of the limb, when the leg is raised (often pain occurs at night) and decreases when the leg falls below the heart level. Pain can be felt in the form of a burning sensation, although it is not characteristic. Approximately 20% of patients with obliterating diseases of the lower extremities do not have clinical symptoms, sometimes because they are not active enough to cause leg ischemia. Some patients have atypical symptoms (for example, a nonspecific decrease in exercise tolerance, hip or other joint pain).

An easy degree of disease often does not cause any clinical manifestations. Moderate and severe degrees usually lead to a decrease or disappearance of the peripheral (popliteal, at the rear of the foot and on the posterior surface of the tibia) of the pulse. If it is impossible to detect the pulse palpation, use Doppler ultrasonography.

When the limb is below the heart level, a dark red coloration of the skin (called dependent redness) may appear. In some patients, lifting of the foot causes blanching of the limb and aggravates ischemic pain. When the leg is lowered, the time of venous filling increases (> 15 s). Edema usually does not occur if the patient keeps his foot still and in a forced position to reduce pain. Patients with chronic obliterating lower limb disease may have thin, pale skin with a decrease or loss of hair. There is a feeling of cold in the distal legs. The affected leg can sweat excessively and become cyanotic, probably due to increased activity of the sympathetic nervous system.

As ischemia progresses, ulcers (usually on the toes or the heel, sometimes on the lower leg, thigh or foot) may occur, especially after a local injury. Ulcers are often surrounded by black necrotic tissue (dry gangrene). They are usually painful, but patients with peripheral neuropathy due to diabetes mellitus or chronic alcoholism may not feel it. Infection of ischemic ulcers (moist gangrene) develops frequently and leads to a rapidly progressing panniculitis.

The level of arterial occlusion affects the symptomatology. Obliterating lower limb disease affecting the aorta and iliac arteries can cause intermittent sensations in the buttocks, hips or lower legs, hip pain and erectile dysfunction in men (Lerish syndrome). In the femoropopliteal OZNA, lameness typically affects the lower leg, the pulse below the femoral artery is weakened or absent. In the OVL of most distal arteries, the femoral-popliteal pulse can be palpated, but on the feet it is absent.

Diagnosis of obliterating diseases of lower extremities

Obliterating diseases of the lower extremities can be suspected clinically, but often the disease is not recognized, because many patients have atypical symptoms or are not active enough to develop clinical manifestations. Radicular syndrome can also cause leg pain while walking, but it is characterized by the fact that pain (called pseudochroma) requires the adoption of a sitting position, not just the cessation of movement to reduce it, and the distal pulse is preserved.

The diagnosis is confirmed by non-invasive examinations. Measure BP on both hands and both legs. Since pulsation on the legs can be difficult to palpate, the Doppler sensor is placed over a. dorsalis pedis or posterior tibial artery. Doppler ultrasonography is often used, because pressure gradients and the shape of the pulse wave can help distinguish the isolated form of OZNA from localization in the aortic bifurcation region from the femoral-popliteal and the variant with the localization of changes in vessels located below the knee level.

The low (0.90) shoulder-ankle index (the ratio of the arterial pressure in the ankle to the arm in the arm) indicates a variant of the disease that can be classified as moderate (0.71-0.90), moderate (0.41-0.0 , 70) or heavy (0.40). If the index is normal (0.91 -1.30), but there is still a suspicion of OZNA, the index is determined after physical exertion. A high index (> 1.30) may indicate a decrease in the elasticity of the wall of the vessels of the legs (for example, with arteriosclerosis of Menkeberg with calcification of the arterial wall). If the index is> 1.30, but suspicion of obliterating diseases of the lower extremities is not removed, additional studies are performed (for example, Doppler ultrasonography, measurement of blood pressure on the 1st toe using a cuff for the toe) to identify possible arterial stenosis or occlusion. Ischemic lesions usually do not heal when systolic blood pressure <55 mm Hg. Art. (<70 mm Hg in patients with diabetes mellitus); Wounds after amputation of the leg below the knee usually heal if AD> 70 mm Hg. Art.

Vasography provides a detailed clarification of the location and prevalence of arterial stenosis or occlusion. According to this study, indications for surgical correction or percutaneous intravascular angioplasty (NDA) are determined. Vasography does not replace non-invasive studies, as it does not provide any additional information about the functional state of pathological sites. VASOGRAPHY WITH MRI AND VASOGRAPHY WITH CT is an atraumatic study that can ultimately supplant contrast vasography.

[7], [8], [9]

Treatment of obliterating diseases of the lower extremities

All patients need active elimination or modification of risk factors, including quitting and controlling the course of diabetes mellitus, dyslipidemia, hypertension and hyperhomocysteinemia. B-Adrenoblockers are safe if the severity of the disease is moderately expressed.

The physical load, for example 35-50 minutes of treadmill test or walking along the path in the load-rest-load regime 3-4 times a week, is an important but uncommon method of treatment. It can increase the walking distance without the appearance of symptoms and improve the quality of life. Mechanisms probably include increased collateral circulation, improved endothelial function due to capillary vasodilation, decreased blood viscosity, improved erythrocyte membrane flexibility, reduced ischemic inflammation, and improved oxygenation of tissues.

Patients are advised to keep their legs below the level of the heart. To reduce night pains, the head can be raised by 4-6 inches (10-15 cm) to improve the flow of blood to the legs.

It is also advised to avoid cold and drugs that cause vasoconstriction (for example, pseudoephedrine contained in many medications for headache and colds).

Preventive care for the feet should be extremely thorough, similar to special care in patients with diabetes:

• daily inspection of the legs for damage and lesions;
• treatment of calluses and corns under the direction of an orthopedist;
• daily washing of feet in warm water with mild soap, followed by gentle but thorough blotting and complete drying;
• prevention of thermal, chemical and mechanical injuries, especially because of uncomfortable shoes.

Antiplatelets can somewhat reduce the symptoms and increase the distance that a patient can pass without clinical symptoms. More importantly, these drugs modify atherogenesis and help prevent attacks of coronary artery disease and transient ischemic attacks. It is possible to administer acetylsalicylic acid 81 mg once a day, acetylsalicylic acid 25 mg with dipyridamole 200 mg once a day, clopidogrel 75 mg inside 1 time per day or ticlopidine inside 250 mg with or without acetylsalicylic acid. Acetylsalicylic acid is usually used in monotherapy as the first drug, then it is possible to supplement or replace with other drugs if the obliterating disease of the lower extremities progresses.

To reduce intermittent claudication, improve blood flow and increase tissue oxygenation in damaged areas, pentoxifylline can be administered 3 times a day 400 mg at meal time or 100 mg cilostazol orally; However, these drugs do not replace the elimination of risk factors and exercise. Taking this drug for 2 months or more can be safe, because adverse effects, although diverse, are rare and mild. The most common adverse effects of cilostazol are headache and diarrhea. Cilostazol is contraindicated in severe heart failure.

Other drugs that can reduce lameness are at the study stage. These include L-arginine (an endothelium-dependent vasodilator precursor), oxidase, vasodilator prostaglandins and angiogenic growth factors (eg, vascular endothelial growth factor, the main fibroblast growth factor). Gene therapy obliterating diseases of the lower limbs are also being studied. In patients with severe limb ischemia, prolonged parenteral use of vasodilating prostaglandins can reduce pain and facilitate healing of ulcers, and intramuscular injection of genetically engineered DNA containing vascular endothelial growth factor can cause the growth of collateral blood vessels.

Percutaneous intravascular angioplasty

Percutaneous intravascular angioplasty with or without stenting is the main non-surgical method for widening vascular occlusions. Percutaneous intravascular angioplasty with stenting can support artery dilatation better than just balloon dilatation, with a lower frequency of reocclusion. Stents have a better effect in large arteries with high flow (iliac and renal), they are less effective in arteries of smaller diameter and with long occlusions.

Indications for percutaneous intravascular angioplasty are similar to indications for surgical treatment: intermittent claudication, which reduces physical activity, pain in rest and gangrene. Curative lesions are short iliac stenoses (less than 3 cm in length) that limit blood flow and short single or multiple stenoses of the superficial femoropopliteal segment. Full occlusions (up to 10-12 cm long) of the superficial femoral artery can be successfully expanded, but the results are better for occlusion with a length of 5 cm or less. Percutaneous intravascular angioplasty is also effective in limited iliac stenosis, located proximal to the shunt of the femoral-popliteal artery.

Percutaneous intravascular angioplasty is less effective in diffuse lesions, long occlusions and eccentric calcified plaques. This pathology most often develops in diabetes mellitus, mainly affecting small arteries.

Complications of percutaneous intravascular angioplasty include thrombosis at the site of dilatation, distal embolization, dissection of the internal membrane of the artery with occlusion of the flap and complications associated with the use of sodium heparin.

With the correct selection of patients (based on complete and well-executed vasography), the initial success rate approaches 85-95% for the iliac arteries and 50-70% for the arteries of the lower leg and thigh. The relapse rate is relatively high (25-35% for 3 years), repeated percutaneous intravascular angioplasty can be successful.

Surgical treatment of obliterating diseases of lower extremities

Surgical treatment is prescribed to patients who can safely endure major vascular intervention and whose severe symptoms do not respond to atraumatic therapies. The goal is to reduce symptoms, cure ulcers and prevent amputation. Since many patients suffer from concomitant IHD, in the light of the danger of acute coronary syndrome, they fall into the category of high-risk surgical treatment, therefore, the functional condition of the patient's heart before surgery is usually assessed.

Thromboendarterectomy (surgical removal of the obturating object) is performed with short limited lesions in the aorta, iliac, common femoral or deep femoral arteries.

Revascularization (for example, the imposition of the femoropopliteal anastomosis) using synthetic or natural (often the saphenous vein of the leg or other vein) of the materials is used to shunt the occluded segments. Revascularization helps to prevent limb amputation and reduces lameness.

In patients who are unable to tolerate extensive surgical intervention, sympathectomy can be effective when distal occlusion causes severe ischemic pain. The chemical sympathetic blockade is similar in efficiency to surgical sympathectomy, so the latter is rarely performed.

Amputation is an extreme measure prescribed for non-severe infection, unrestrained pain at rest and progressive gangrene. Amputation should be as distal as possible, with the knee retained for optimal use of the prosthesis.

External compression therapy

External pneumatic compression of the lower limb, serving to increase distal blood flow, is the method of choice for salvaging the limb in patients with severe disease and unable to undergo surgical treatment. Theoretically, it reduces edema and improves arterial blood flow, venous outflow and oxygenation of tissues, but studies in favor of using this method are not enough. Pneumatic cuffs or stockings are placed on the shins and fill rhythmically during diastole, systole or parts of both periods for 1-2 hours several times a week.

[10], [11], [12], [13], [14], [15], [16]