arteriosclerosis obliterans
Introduction
Introduction to occlusive arteriosclerosis The disease mainly refers to a non-inflammatory vascular disease in which the peripheral arteries cause stenosis or occlusion due to atherosclerotic lesions, and then produce various symptoms and signs on the basis of insufficient blood supply. Peripheral vascular occlusive arteriosclerosis is a part of systemic arteriosclerosis. Its etiology and risk factors are similar to those of arteriosclerosis in other areas. Old age, hypertension, dyslipidemia and diabetes are the main causes. During aging, intraarterial Under the action of the injury factor, the endothelial cells are damaged and detached. On this basis, thrombus formation is repeated, accompanied by a large amount of lipoprotein infiltration and stasis, and endothelial cell proliferation and fiber formation cause arteriosclerosis. basic knowledge The proportion of illness: the probability of illness in the elderly is 0.38% Susceptible people: men and women who are more than 60 Mode of infection: non-infectious Complications: impotence aneurysm
Cause
Cause of occlusive arteriosclerosis
(1) Causes of the disease
Peripheral vascular occlusive arteriosclerosis is a part of systemic arteriosclerosis. Its etiology and risk factors are similar to those of arteriosclerosis in other areas. Old age, hypertension, dyslipidemia and diabetes are the main causes. During aging, intraarterial Under the action of the injury factor, the endothelial cells are damaged and detached. On this basis, thrombus formation is repeated, accompanied by a large amount of lipoprotein infiltration and stasis, and endothelial cell proliferation and fiber formation cause arteriosclerosis.
(two) pathogenesis
The mechanism of the disease is still difficult to clarify, but it can be caused by various factors such as vascular endothelial injury theory, lipid infiltration theory, thrombosis theory, etc., molecular biology research proves that the blood vessel wall cells and blood There are interactions between the formation and the active role in the pathogenesis, such as endothelial damage, the amount of cholesterol-containing low-density lipoprotein in the plasma increases and penetrates into the intima, and then stimulates smooth muscle migration from the middle layer of the artery to the intima, and proliferation is the most important. Incidence factor.
Pathological manifestations of lesions are segmental, involving large and medium arteries, arterial intima atherosclerotic plaque formation, increased connective tissue matrix in the intima and lipid-like deposition, causing intimal cell proliferation, luminal stenosis, When the endometrium is destroyed, plaque necrosis and ulceration, causing thrombosis, leading to occlusion of the lumen, causing ischemia of the extremities, recanalization after thrombus formation, and collateral circulation at both ends of the occlusion, in addition, the wall of calcium Deposition, a small number of cases due to arterial dilation into an aneurysm.
Occlusive arteriosclerosis is more common in the lower aortic aorta, radial and femoral arteries, upper extremity arteries are less involved, occasionally in the proximal subclavian artery and ulnar artery, some elderly or patients with diabetes, lesions can occur first In smaller arteries, such as the anterior and posterior tibial arteries, the arteries often expand and become harder, with a cord-like or irregular twist.
The degree of ischemia in the affected limb depends on the location, extent, extent of occlusion, and the degree of compensatory collateral circulation. When the arterial circulation is blocked, the neck, shoulder strap and elbow are abundant. The collateral net may be sufficient to prevent ischemic symptoms, which are usually caused by obstructive lesions of the subclavian and brachial arteries near the aortic arch. Less than 75% of vascular stenosis usually does not affect blood flow at rest. Vascular stenosis 60% can cause limb ischemia during exercise, skin atrophy and thinning after ischemia of the affected limb tissue, subcutaneous fat disappears and is replaced by fiber and connective tissue, bone is sparse, muscle atrophy, and ischemia Sexual neuritis, gangrene can occur in the later stage, gangrene often starts from the end of the affected limb, can be confined to the toe, can also extend to the foot or calf, but rarely exceeds the knee joint, diabetic patients are prone to gangrene and tissue infection.
Prevention
Occlusive atherosclerosis prevention
1. Patients should avoid cold, do not bathe or swim in cold water.
2. Wear warm clothes in winter and walk often to promote blood circulation.
3. Never heat the feet, avoid sun exposure on the feet and calves, wash your feet with warm water (close to body temperature), and dry thoroughly.
Complication
Obstructive arteriosclerosis complications Complications, impotence aneurysms
Complicated with vasogenic yang, microcirculation embolism, aneurysm, tissue ulceration and necrosis after gangrene infection.
Symptom
Symptoms of occlusive arteriosclerosis Common symptoms Muscle spasm pain, dry gangrene, intermittent cramps, hypertension, atherosclerosis
More men than women, the average age of onset is 60 years old, and the incidence of diabetes is earlier, the lesions mainly occur in elastic and muscular arteries, such as the aorta, radial artery, femoral artery, coronary artery, renal artery and aorta Branching, and often in the inner side of the opening of the blood vessel branch, or the site where the blood vessel is fixed in the surrounding tissue, the stenosis or occlusion of the lumen caused by the arterial lesion, resulting in insufficient blood supply to the distal end of the lesion, the severity of which depends on the occlusion site, degree, The range and the degree of compensation after the establishment of the collateral circulation and the rate of development of limb ischemia are different. Atherosclerosis is a systemic arterial disease. If the arteries of the extremities are involved, the symptoms of the lower extremities are often severe. Quickly, when the collateral circulation is difficult to establish in time and the compensatory function is limited, the patient begins to experience painful symptoms of typical intermittent claudication and limb rest. Intermittent claudication is muscle spasm during exercise, tension or fatigue, after rest Rapid relief, walking again and again, another important symptom is rest pain, peripheral nerve nourish vascular disease, causing blood As a result of insufficient ischemic neuritis, this pain is characterized by increased at night, reduced drooping or cold, lower abdominal aortic or radial artery lesions, intermittent claudication symptoms in the buttocks and lower extremities; femoral artery or Radial artery disease, the symptoms appear in the calf and intestines of the calf. Because of the activity of the gastrocnemius during exercise, even the abdominal aorta-radial artery disease can cause intermittent claudication. Other symptoms of ischemia are the affected limb, especially the toe. Cold feeling, abnormal feeling, pale or bruising, although the degree of ischemia is light and persistent, it causes atrophy of skin and subcutaneous adipose tissue, hair loss, toenail deformation and sparse bone, etc., such as ischemia, significant toe, foot or Dry gangrene or ulceration occurs in the lower leg. In addition, the distal pulsation of the lesion is weakened or disappeared, the blood pressure is reduced or disappeared, and a murmur-like murmur is heard in the stenosis.
Patients may be associated with hypertension, diabetes or atherosclerotic symptoms of the eye, brain, heart, kidney and mesentery. The superficial artery, such as the radial artery, is cord-like or irregularly distorted.
Examine
Examination of occlusive arteriosclerosis
1. Determination of blood lipids, blood triglyceride and cholesterol often increase, lipoprotein typing shows that more than 90% of patients with type II or IV high wax proteinemia.
2. Blood sugar, urine sugar and glucose tolerance test tests often have positive findings.
3. Segmental arterial pressure measurement: Segmental arterial pressure measurement refers to measuring the arterial systolic pressure in each plane of the limb, including the distal finger, the systolic pressure of the toe, and calculating the ratio of the systolic blood pressure of the upper and lower limbs, thereby judging the ischemia of the lower limbs. The scope and extent of the Doppler ultrasound diagnostic apparatus are also widely used, and the auscultation of the bell-shaped stethoscope can also be used for auscultation.
(1) Ankle blood pressure measurement method: After the cuff is wrapped around the ankle, the Doppler instrument is used to measure the blood flow in the anterior or posterior tibial artery. The stethoscope can also be used to auscultate the ankle/arm index (A/Brachial index, A/ B index): The A/B index refers to the ratio of the posterior tibial arterial pressure to the ipsilateral upper brachial artery pressure. The normal value is 1.0. The clinical significance of measuring the A/B index is:
1 to determine the severity of lower limb ischemia, the degree of index reduction is generally consistent with the severity of lower limb ischemia, such as intermittent claudication when the A / B index is 0.5 ~ 0.8, resting pain and gangrene index < 0.5.
2 observe the effect of arterial bypass grafting.
(2) Determination of the absolute value of segmental arterial pressure: The clinical value of determining the absolute value of segmental arterial systolic pressure is:
1 to determine the trend of ischemic gangrene, the general radial artery pressure > 8.0kPa (60mmHg), limb survival rate of 86%; pressure <8.0kPa, the survival rate was 77%.
2 Select amputation plane reference, arterial pressure > 6.7kPa (50mmHg) can be amputated under the knee; when no arterial blood flow is detected, lap amputation should be selected.
3 segmental arterial pressure simultaneously measured the corresponding segment of blood pressure difference, or bilateral limb symmetrical blood pressure difference > 2.7kPa (20mmHg), suggesting the determination of local proximal artery stenosis or occlusion.
4. Percutaneous oxygen partial pressure measurement By measuring the partial pressure of oxygen in the local tissue, the local tissue blood perfusion can be indirectly understood, and the resting state, body position change and exercise repeated detection and analysis can help to understand the local blood supply indirectly. To guide the clinical determination of amputation level, to determine the healing trend of surgical wounds and the effect after bypass surgery.
5. Doppler ultrasound detection of color Doppler ultrasound can directly observe the size of the limb arterial diameter, blood flow and changes in arterial pulsation conduction time, so as to determine the location and severity of the lesion.
6. Magnetic resonance imaging MRI can clearly show the atherosclerotic plaque protruding into the cavity of the aorta and radial artery, stenosis and obstruction of the lumen, and complications after vascular surgery, such as hemangioma, arterial dilation Etc., but it is more difficult to show stenotic lesions of smaller branches below the femoral artery, and it is difficult to show calcified plaques. Therefore, MRI can not completely replace the angiography before surgery.
7. Peripheral angiography Percutaneous puncture of the femoral artery can be performed as needed above the renal artery branch of the abdominal aorta for bilateral or unilateral lower extremity angiography. Arterial angiography can identify the location, extent and severity of the lesion. No, whether and how to treat surgery, but angiography can not quantitative analysis of local tissue perfusion, so the clinical need to combine local arterial pressure and oxygen partial pressure detection, in order to make a more accurate judgment.
8. Fundus examination directly observes the presence or absence of arteriosclerosis and determines the degree of hardening and the rate of progression.
Diagnosis
Diagnosis and diagnosis of occlusive arteriosclerosis
Older people, especially those with hypertension, diabetes and hyperlipidemia, have chronic ischemic manifestations of lower extremities. The disease may be suspected if the arterial pulsation is weakened or disappeared. You can use limb volume scan and Doppler ultrasonography, according to the pressure. And the rolling index, segmental blood pressure and wave pattern analysis, comprehensive judgment of lower extremity arterial occlusion and obstruction plane, the above two methods and radionuclide scanning and infrared imaging technology and other non-invasive examination methods are especially suitable for the elderly, Although atherosclerosis is more painful, it is still the most reliable diagnostic method. It can understand the location of obstruction, the degree of obstruction and the establishment of collateral circulation, and provide a basis for surgical treatment.
In the elderly, attention should be paid to the differentiation of arterial embolism. Thromboangiitis obliterans and multiple arteritis are common in young people, and there is no difficulty in identification.
