Acute arterial occlusion of extremities
Acute arterial occlusion is result of the sudden termination of a blood-groove in an extremity. Clinical manifestations depend on level, a pas which there is occlusion, extents of defeat and a possibility of a collateral blood-groove (existence previous kollateralen). Usually the thromboembolism or local tromboobrazovapy is the reason of acute arterial occlusion.
Heart, aorta and large vessels is a source of a thromboembolism of an arterial bed, and such thromboembolisms at fibrillation of auricles (paroxysmal and constant forms), an acute myocardial infarction, aneurism of a left ventricle of heart, cardiomyopathies are observed, at infectious and other forms of an endocarditis, patients with the fitted a prosthesis valves have hearts, with a myxoma of the left auricle. The changed aorta and large vessels, and also aortic aneurysms or large vessels can be sources of tromboembol atherosclerotic. Much less often emboluses get to an arterial bed from venous, i.e. from deep veins of the lower extremities, veins of a basin or from the right cameras of heart — so-called paradoxical embolisms. It is observed at the patients having an open oval opening or other defects of an interatrial or interventricular partition.
Usually emboluses are got jammed in places of a branching of arteries and in their distal departments where the gleam of a vessel decreases. Concerning the lower extremities it is noticed that fixing of emboluses most often happens in femoral arteries, then with the decreasing frequency there are embolisms of ileal arteries, aortas, popliteal arteries and arteries of a shin.
Acute thrombosis of in situ usually arises in atherosclerotic the changed arteries — in places their stenozirovaiiya or an aneurysm, or in the form of thrombosis of shunts. Blood clots can be formed also in places of injuries, punctures or at catheterization of arteries. Acute arterial fibrinferments can be observed at the states which are characterized by hypercoagulation at an erythremia, a gipergomotsisteinemiya.
Clinical manifestations of acute arterial occlusion
In general at an embolism a clinical picture usually much more acute (quite often develops within several minutes), than at fibrinferment when manifestations can accrue within hours, and even days. Emergence of sharp pains in an extremity, its blanching (sometimes developing of "spotty" cyanosis), an extremity cold is characteristic. The hyperesthesia or anesthesia is noted it, the spasm of muscles or a decubital paralysis is observed. Pulse distalny places of occlusion is absent, the superficial veins which are fallen down. If the blood stream is not recovered, the skin necrosis appears, then — extremity gangrene.
The question of what caused acute arterial occlusion in the patient — an embolism or thrombosis, is almost important in connection with distinctions in treatment tactics. An essential role is played by the anamnesis and results of the previous researches. For example, existence at the patient of valve damages of heart, aneurism of heart, fibrillation of the auricles and other states contributing to thromboembolisms can incline the doctor in favor of the assumption of the embolic nature of acute arterial occlusion.
Transesophageal EhoKG allows to distinguish vegetations on valves, thrombosis of the left auricle. Existence in the anamnesis of the alternating lameness of the lower extremities, okklyuziruyushy damages of upper extremities, the states which are followed by hypercoagulation forces to assume trombotichesky occlusion. The angiography also gives help in differential diagnosis of the embolic and trombotichesky nature of acute arterial occlusion.
Treatment of acute arterial occlusion
Approaches to treatment of patients with acute arterial occlusion of extremities can differ depending on whether occlusion is embolic or trombotichesky. Anyway the affected extremity has to be in horizontal position at the level of a trunk of the patient lying in a bed — or is slightly lower. The extremity has to be covered only with a sheet, on a bed there should not be folds. It is impossible neither to warm an extremity, nor to cool. In all cases begin intravenous administration of heparin at once (see. "Myocardial infarction") that allows to reduce degree of an arteriospasm and gives chance to warn distal thrombosis.
At an embolism no later than 4 — 6 h from emergence of clinical symptoms the embolectomy has to be made — it is carried out after an arteriotomy by means of Fogardi's catheter. Also operational recovery of a blood-groove by shunting or prosthetics of a vessel is possible. At trombotichesky occlusion the thrombectomy is sometimes made, however the extent of a zatrombirovanny site is usually rather big that interferes with extraction of blood clot. Very effective can be a thrombolysis, especially at local use of trombolitik. Perhaps also recovery of a blood-groove by means of surgical or endovascular methods.
The forecast is defined by the place of defeat (the proksimalny occlusion, the is more serious the forecast), extent of development of collaterals, timeliness of recovery of a blood-groove, existence of background diseases, first of all — an ischemic heart disease, a diabetes mellitus. If revascularization is not made (or it was late), there is a high risk of a gangrenosis and loss of an extremity.