Obliterating thromboangiitis

Obliterating thromboangiitis is an inflammatory thrombosis of small arteries, medium sized arteries and some superficial veins causing arterial ischemia of the distal limbs and superficial thrombophlebitis. The main risk factor is smoking. Symptoms of obliterating thromboangiitis include lameness, non-aching leg ulcers, rest pain and gangrene. Diagnosis is established by clinical examination, non-invasive vascular studies, angiography and exclusion of other causes. Treatment of obliterating thromboangiitis involves the cessation of smoking. The prognosis is very good in refusing to use tobacco, but when the patient continues to smoke, the disturbances inevitably progress, often leading to the need for limb amputation.

Obliterating thromboangiitis occurs almost exclusively among smokers and predominates in men aged 20-40 years.

Only about 5% of cases are recorded in women. The disease is more common in people with the genotypes HLA-A9 and HLA-B5. Prevalence is highest in Asia, in the Far and Middle East.

Obliterating thromboangiitis causes segmental inflammation in the small and medium arteries, and often in the superficial veins of the extremities. In acute obliterating thrombangiitis, occlusive thrombi are accompanied by neutrophilic and lymphocytic infiltration of the inner shell of the vessels. Endothelial cells proliferate, but the inner elastic plate remains intact. In the intermediate phase, thromboses are organized and are not completely recanalized. The middle layer of vessels is preserved, but can be infiltrated by fibroblasts. In later stages, periarterial fibrosis may develop, sometimes with involvement of adjacent veins and nerves.

[1], [2], [3]

What causes obliterating thromboangiitis?

The reason is unknown, although cigarette smoking is a major risk factor. The mechanism may include hypersensitivity or toxic vasculitis. According to another theory, thromboangiitis obliterans can be an autoimmune disorder caused by a cell-mediated response to human type I and III collagen that is part of the blood vessels.

Symptoms of obliterating thromboangiitis

Symptoms are the same as with arterial ischemia and superficial thrombophlebitis. Approximately 40% of patients in the history have an indication of migrating phlebitis, usually in the superficial veins of the shin or foot. The beginning is gradual. The distal vessels of the upper and lower extremities are affected, then it progresses proximally, culminating in the development of distal gangrene and constant pain.

Feeling cold, numbness, tingling or burning sensation may appear before the development of objective signs of the disease obliterating thromboangiitis.

Often reveal the phenomenon of Raynaud. Intermittent claudication is possible in the injured limb (usually in the arch of the foot or leg, less often in the arm, hand or thigh), capable of progressing to pain at rest. If the pain is intense and constant, the usually affected leg is constantly cold, sweats excessively and becomes cyanotic, probably due to an increase in the tone of the sympathetic nervous system. Ischemic ulcers develop in most patients and can progress to gangrene.

The pulse is reduced or absent on one or more leg arteries and often on the wrist. In young people who smoke and have ulcers of limbs, Allen's positive test (the hand remains pale after the researcher simultaneously compresses the radial and ulnar arteries, and then alternately releases them) confirms the diagnosis. Often, paleness is noted during lifting and redness when lowering the affected hands, feet or fingers. Ischemic ulceration and gangrene, usually one or more fingers, are able to develop early, but not acutely. In non-invasive studies, a strong decrease in blood flow and blood pressure is detected in the affected fingers, legs and toes.

Diagnosis of obliterating thromboangiitis

Presumptive diagnosis is made when collecting anamnesis and physical examination. It is confirmed by the following data:

• Shoulder-ankle index (ratio of systolic blood pressure in the ankle joint to BP on the arm) or segmental pressure change on the upper limbs indicates distal ischemia;
• echocardiographically excluded emboli, migrated from the cavities of the heart;
• blood tests (eg, determination of the content of antinuclear antibodies, rheumatoid factor, complement, anti-centromeric antibodies, aHTH-SCL-70 antibodies) exclude vasculitis;
• tests for antibodies to phospholipids exclude antiphospholipid syndrome (although the amount of these antibodies can be slightly increased with obliterative thrombangiitis);
• vasography shows characteristic changes (segmental occlusions of the distal arteries in the arms and legs, convoluted swirling collateral vessels around the occlusion, absence of atherosclerosis).

[4], [5], [6], [7]

Treatment of obliterative thromboangiitis

Treatment involves stopping smoking. Continued use of tobacco inevitably leads to the progression of the disease and severe ischemia, often leading to the need for amputation.

Other measures include the elimination of hypothermia, the abolition of drugs that can cause vasoconstriction, and the prevention of thermal, chemical and mechanical damage, especially due to poorly selected footwear. In patients in the first phase of quitting smoking, iloprost in 0.5 to 3 ng / kg per minute intravenously for 6 hours or more can help prevent amputation. Pentoxifylline, calcium channel blockers and thromboxane inhibitors can be prescribed empirically, but there is no evidence to confirm their effectiveness. There is a study of the possibility to control the course of the disease by determining the content of anti-endothelial antibodies.