Peripheral arterial embolism
Introduction
Introduction to peripheral arterial embolism Peripheral arterial lembolism refers to the blockage of peripheral arteries by a thrombus or embolus from a certain site, which in turn causes acute ischemia at the distal end, which is characterized by acute ischemic pain and necrosis, and directly affects the autonomy of life. basic knowledge The proportion of sickness: 0.01% Susceptible people: no specific population Mode of infection: non-infectious Complications: ischemic necrosis
Cause
Peripheral arterial embolism
(1) Causes of the disease
The main cause of acute peripheral arterial embolism is arterial emboli (thrombotic or other types of emboli). The heart is the most common source of embolism. When atrial fibrillation or mitral stenosis is combined, left atrial blood flow is disordered, and the flow rate is slowed down. It is easy to form a left atrial thrombus. Other heart diseases that can cause thrombosis include myocardial infarction, ventricular aneurysm and cardiomyopathy; infectious thrombosis in patients with infective endocarditis comes from mitral or aortic valve mites; distal Thromboemboli can also originate from proximal aortic or aortic lesions (such as aneurysms, atherosclerosis). It is rare that a venous embolus enters the artery through an patent foramen ovale and causes embolism. In addition, it comes from a calcified valve. Calcium fragments, atherosclerotic cholesterol crystals, malignant tumor thrombi and other foreign bodies can be emboli, but extremely rare, the following conditions can form arterial thrombosis in situ, about 10% of cases of occlusive arteriosclerosis Acute arterial embolism can occur, but occlusive vasculitis and nodular polyarteritis are rare, in some blood abnormalities such as polycythemia or cryoglobulinemia Although blood vessels are normal, blood coagulation is increased, acute arterial embolism, penetrating trauma to arteries, placement of arterial catheters and arterial bypass grafts, and non-cardiovascular diseases such as sepsis, pneumonia, and peritonitis may occur. Tuberculosis, ulcerative colitis, etc. may cause arterial embolism.
(two) pathogenesis
The embolus from the heart or aneurysm is transported to a certain artery along with the blood flow, easily invaded at the bifurcation of the artery or the diameter of the artery is narrowed, causing vascular obstruction, sputum, femoral artery and its bifurcation. At the site of the hair, the distal end of the obstruction is blocked or stopped. The further extension of the embolus causes severe ischemia or even necrosis of the distal tissue. The natural outcome of the embolus is different. Some of the emboli are broken into pieces and are rushed to the distal blood vessel by the blood flow. Some emboli can dissolve by themselves; some emboli are machined and finally recanalized.
The pathophysiology of acute arterial embolization is preceded by local pathological changes, which then affect the whole body. After arterial embolization, the nerve endings of the arterial wall are stimulated, and the distal vascular and adjacent arterial vasospasm are caused by the sympathetic reflex of the sympathetic nerve; Platelet release of serotonin, histamine, aggravation of ischemia in the distal tissues of the artery, severe ischemia and hypoxia, degenerative changes in tissue structure, degeneration of endothelium, massive cellulose deposition, if the blood vessels quickly recanalize, Restoring blood supply, this change can be reversed and returned to normal. If it is blocked for a long time, the arterial subendocardial edema, elastic fiber breaks, thickens, 7 days later, all blood vessels in the blood vessels form, interstitial edema, cellulose polymerization In a cluster or mesh, due to slow blood flow, degeneration of the arterial wall, destruction of the intima of the arteries, release of blood clots by thrombus, release of histamine from platelets, serotonin, ADP, etc., further promote blood coagulation, secondary thrombosis Formed and extended to both ends.
Different parts of the thrombus have different effects on the body. The severity and breadth of the part depends on the size of the blocked blood vessel, the location and the collateral circulation, the larger the blocked artery, and the heavier the degree of ischemia, the wider the range of influence. When the larger arteries are obstructed (such as sputum, femoral artery), distal acute ischemia, lower limb skin color changes, sensory, dyskinesia, pulse pulsation disappears, and then cause tissue cell necrosis, generally tissue necrosis occurs 6 h after embolization, After 12h, gangrene appeared.
Thromboembolism not only affects the distal end of the embolization site, but also affects the whole body. After arterial embolization, hemodynamics, nerves, body fluids and other factors increase the burden on the original pathological heart, which inevitably aggravates cardiac dysfunction and tissue necrosis. (especially large area necrosis) can cause metabolic disorders, such as azotemia, hyperkalemia, proteinuria, metabolic acidosis, and severe renal failure, usually starting 10 to 12 hours after embolization.
Prevention
Peripheral artery embolism prevention
1. Active treatment and prevention of the primary disease causing thrombosis is the key to prevention and treatment of peripheral arterial embolism.
2. During the catheterization and operation, the technique should be gentle to prevent the plaque on the vessel wall from falling off or carrying foreign matter during operation, resulting in thromboembolism.
Complication
Peripheral arterial embolization complications Complications ischemic necrosis
Common complications of the disease include numbness, pain, intermittent claudication of the affected limb, and severe ischemic necrosis of the affected limb.
Symptom
Symptoms of peripheral arterial embolism Common symptoms Skin pale aorta Blood supply disorder Severe pain Hair loss Fatigue Surgery wound no longer bleeding Body pain Sports dysfunction Limb embolism Sensation
The clinical manifestations of thromboembolism depend on the location, duration and severity of embolization. Acute arterial embolism can occur at any age. The age of embolism caused by rheumatic valvular heart disease is younger. The age of onset of coronary heart disease is greater. In limb arterial embolization, the most common is lower extremity spasm, femoral artery embolization, the most common site is in the hernia, femoral bifurcation and distal femoral artery.
1. Pain: Pain is the earliest symptom. About half of the patients have severe pain in the lower extremity after onset. The nature is sharp pain, radiating from the calf to the foot, and there is tissue ischemia.
2. Paresthesia: The affected limb is accompanied by numbness and chilliness at the same time as the pain. The skin at the distal end of the embolization is weakened or disappeared. The proximal end has hyperesthesia, acupuncture and tenderness. If the superficial artery is embolized, There may be tenderness in the area where the embolus is located.
3. Motor dysfunction: embolism leads to acute ischemia of limb muscles, fatigue and weakness during exercise, weak muscle strength, severe paralysis, passive movement of the limb with pain, deep reflex disappears.
4. Limb arterial pulsation disappears or weakens: Because the embolus obstructs blood flow, arterial spasm, and secondary thrombosis, the arterial pulsation at the distal end of the embolization disappears, such as the radial artery embolization, the femoral artery, the radial artery, and the dorsal artery of the foot. The posterior iliac artery pulsation disappeared.
5. Skin changes: Generally, the ischemic skin changes occur about 10 cm below the embolization site, which is characterized by pale skin, striated or blemishes, venous blood emptying due to reduced or interrupted arterial blood supply, and low skin temperature and coldness. Feeling, limb circumference is reduced, skin changes and pulse beat disappear and coexist as evidence of tissue ischemia.
In addition, when the embolism occurs in a part of the collateral circulation, the symptoms may be inconspicuous or manifest as intermittent claudication, that is, the patient has evidence of ischemia while the walking distance is shortened, and the symptoms are relieved after the break, but if the walking is performed Shortened sex, suggesting that the condition continues to increase.
Examine
Peripheral arterial embolization
Commonly used inspection methods are:
1. Color Doppler ultrasonography.
2. Magnetic resonance angiography.
3. Angiography or digital subtraction angiography It can provide the most detailed and accurate disease data, such as the location, extent and extent of the lesion, and provide a basis for the choice of angioplasty or surgical approach.
4. ECG and X-ray examination, you can understand the primary disease.
Diagnosis
Diagnosis and diagnosis of peripheral arterial embolism
Diagnostic criteria
According to the basic diseases of patients with thrombosis (such as mitral stenosis, atrial fibrillation, mechanical valve implantation), the history of arterial embolism, sudden clinical symptoms and corresponding ischemic signs, it is generally difficult to diagnose peripheral arterial embolism. It is necessary to make clear at the time of diagnosis: whether the arterial embolization, the site of embolization, and the site where the skin feels disappeared can also be confirmed by invasive or non-invasive examination, and the location, extent, and basis for selecting treatment methods are also clarified. .
Differential diagnosis
1. Arterial thrombosis: This disease usually occurs on the basis of arterial disease. The symptoms are very similar to arterial thromboembolism. However, the onset of the disease is not as good as the embolism. The history often has chronic ischemia. Intermittent claudication, limb numbness, toenail deformation, muscle atrophy, arterial pulsation weakened or disappeared, skin temperature is low, but the sensory disorder plane is not as clear as embolization, laboratory examination: blood cholesterol increased, X-ray showed calcification on the arterial wall, artery The angiography showed that the wall was narrow, not smooth or interrupted, and there were more collateral circulation around it.
2. Deep vein thrombosis: deep vein thrombosis, swelling of the lower extremities, skin blemishes but normal or slightly higher temperature, vein dilatation, gastrocnemius tenderness, but severe edema compression arteries produce blood supply disorders, easily confused with arterial embolism, after arterial embolization It is also easy to secondary to deep vein thrombosis, so you need to ask for a detailed history and pay attention to the process of changes in symptoms.
3. , acute thrombotic vasculitis of the femoral vein: patients may have weakened arterial pulsations, and have ischemic manifestations similar to arterial embolism, but patients with this disease have obvious edema, venous filling and weak arterial pulsation, Helps identify.
