Under aortic aneurysms mean the irreversible expansion of one of its sites twice exceeding the normal diameter of a vessel. Normal at adults diameter of an aorta in the ascending department makes about 3 cm, in the descending chest part — 2,5 cm and in belly part — 2 cm. Distinguish true aortic aneurysms at which there is a protrusion of all three layers of a vascular wall, and false (pseudoaneurysms); in the latter case there is a protrusion only of a periblast that happens at a rupture of an intima and the center. Aneurisms can be formed not only in an aorta, but also in its branches and in peripheral arteries, and they are also subdivided on true and false.
True aortic aneurysms happen spindle-shaped when there is an expansion of a segment of an aorta on all perimeter of a vessel, and meshotchaty — they are formed at protrusion only of part of a segment of a vessel.
Distinguish aneurisms of chest and belly departments of an aorta. The chest department of aneurism can be located in the ascending part, an arch and the descending part; the belly department of an aorta of aneurism most often is located infrarenalno. Existence of multiple aortic aneurysms is possible: most often the combination of aneurisms of the descending chest department of an aorta and infrarenalny aneurisms meets. Aneurisms of belly department of an aorta are prevailing: their frequency about 85%, and the rest is the share of aneurisms of chest department.
The leading role in development of aortic aneurysms is played by atherosclerosis. The noticeable place is taken also by dystrophic processes in an average cover against hereditary disturbances in structure of connecting fabric — Marfan's syndromes, Elers — Danlo, Erdkhaym's syndrome (an aortoannulyarny ectasia), hereditary deficit of elastin (pseudoxanthoma elasticum), incomplete forms of the listed diseases, and also options which nosologically are less accurately outlined for which the name "connective tissue dysplasias" is offered.
The supervision which showed that about 20% of patients with aortic aneurysms have the close relatives having the same pathology testify to a role of hereditary factors. Mutations in a gene of procollagen III of type can lead to development of aortic aneurysms in several family members.
Aortic aneurysms happen also at immunoinflammatory and infectious damages of an aorta, however their role in development of aneurisms is less considerable, and the reasons are very diverse (see above).
The pathogeny of a disease is connected with a superactivity of proteinases that leads to destruction of an elastic framework of an aorta. In wider plan disturbance of balance between activity of fabric proteinases, especially metalproteinases, and their inhibitors plays a role. Also the change of structure of collagen connected with hereditary factors matters. Distinctions in an etiology of aneurisms of chest and belly departments of an aorta are observed. Aneurisms of chest department more often happen at hereditary connective tissue disturbances, inborn crimpiness of an aortic arch, at aorta coarctation. However atherosclerosis, syphilis, aortites and injuries can also be the reasons of development of aneurisms of chest department.
In an etiology of aneurisms of belly department atherosclerosis prevails, the value and an injury keeps; much less often formation of aneurisms of this localization is observed as a result of aortites or hereditarily the caused changes in structure of connecting fabric.
Clinical displays of aneurism of belly department of an aorta
As it was already mentioned, aneurisms of belly department of an aorta meet considerably more often than aneurisms of chest department.
Tell about aneurism of belly department of an aorta when diameter of a venter is equal or exceeds 4 cm. Most often aneurisms of this localization are found in men 50 years are more senior. In most cases aneurisms are located below an otkhozhdeniye of a renal artery and if expansion rather extended, then it can extend also to ileal arteries.
Clinical manifestations to a bowl of all are absent, and usually aneurisms find accidentally — at physical and/or tool inspection of the patient in other occasion. Sometimes patients show complaints to a pulsation in a stomach or mild pains in spin — the last to a bowl happen at aneurisms of an inflammatory origin (at aortites). At auscultation over aneurism the systolic noise arising owing to turbulence of a blood flow in it is quite often listened.
As aneurisms of belly department of an aorta usually develop against atherosclerosis, is explainable that approximately at 1/4 such patients the alternating lameness is observed, and at an aortografiya find atherosclerotic damage of renal arteries in part of patients. It is noticed that at patients with aneurism of a ventral aorta quite often find also aneurism of a popliteal artery. Even the small aortic aneurysm can become a thromboembolism source — it causes various degree of insufficiency of blood supply of the lower extremities. Sometimes aneurism leaks — blood gets into a vascular wall, perivascular space that is followed by pains, morbidity at a palpation and usually foretells a rupture of aneurism. However in many cases the rupture of aneurism occurs suddenly, without the previous symptoms.
Clinical picture of aneurisms of chest department of an aorta
In many cases of aneurism of chest department of an aorta are asymptomatic and are distinguished at the radiological and ultrasonic researches made in other occasions. However at some patients, mainly with big aneurisms, pains can be watched a breast, and in a neck which have persistent character and do not concede in spin to effect of nitroglycerine ("aortalgiya"). Believe that these pains are connected not only with expansion of the aorta, but also are caused by the aneurism pressure upon surrounding fabrics and nervous educations.
The prelum aneurism of a trachea causes short wind, cough, stidor breath; a gullet — a dysphagy: the left recurrent nerve — hoarseness of a voice; an upper vena cava — puffiness of the person, neck, swelling of veins of a neck. The breast pulsation is less often observed, and at a X-ray analysis in such cases breast erosion owing to aneurism pressure can be found. At aneurisms of the ascending part the aortal ring can extend and there is aortal regurgitation with characteristic protodiastolic noise. Owing to turbulence in blood flow aneurism at auscultation quite often note systolic noise which localization depends on an arrangement of aneurism and on nature of carrying out noise.
In rare instances — if blood transudes in a wall of aneurism and perivaskulyarno, there can be a message of a wall of aneurism with a bronchial tube and the pneumorrhagia appears. At aneurism of the descending part of chest department pleural pains, and also the shoulder pains caused by irritation of a phrenic nerve sometimes are observed.
In aneurisms blood clots are quite often formed that can lead to thromboembolisms on a big circle of blood circulation.
Clinical it is shown a rupture of an aortic aneurysm
At a rupture of an aortic aneurysm the strongest stethalgias, a stomach are observed, arterial hypotension with a shock picture, and most of patients die the first minutes, is more rare — the first hours after a gap.
The risk of a rupture of aneurism depends on its size: during 5 flyings it makes for aneurisms less than 5 cm in size — 1 — 2%, and for aneurisms with a diameter more than 5 cm — 20-40%.
Tool methods of recognition of aneurisms
The aortic aneurysm can be distinguished by means of BONDS researches, at the same time in aneurisms of a ventral aorta often find calcification signs. For clearing of the diagnosis also computer or magnetic and resonant tomography can be used. Aortografiya is carried out in cases when an operative measure is planned.
Treatment of patients with aortic aneurysms
At aneurisms with a diameter less than 5 cm apply waiting tactics; at patients with arterial hypertension at the same time carry out correction of arterial pressure by means of β-adrenoblockers.......... The patient with mycotic aneurisms or with a syphilitic mesaortitis appoint antibacterial treatment.
At patients with quickly growing aneurisms, at the persons having clinical manifestations (pains, prelum symptoms, etc.), in the presence of aneurisms with a diameter more than 5 cm in belly department and more than 6 cm — in chest department, carry out surgical or endovascular treatment.
The resection of aneurism and plastic of an aorta synthetic or gomotransplantaty is carried out. At operations on chest department in cases of the expressed aortal insufficiency carry out as well prosthetics of the aortal valve. At patients with aneurism of a ventral aorta apply endovascular prosthetics with installation of a stent more often; this method is implemented also at treatment of aneurisms of a chest aorta recently, and also at aneurisms of other large vessels.