Aneurysm of the ascending aorta

Pathologies of the thoracic aorta are quite common, and more than half of the cases involve such a disorder as an aneurysm of the ascending aorta. The disease threatens serious complications that develop in the natural course of pathological dilations, and is associated with high lethality, complex approaches to treatment. Only early detection of the problem and timely assistance of the surgeon can reduce the incidence of complications and increase the survival rate in this pathology. [1]

Epidemiology

Aneurysm of the ascending aorta is one of the common aortic pathologies: the incidence rate is about 5-10 cases per hundred thousand population annually. At the same time, more cases affect men (2.3 times more). The risks also increase depending on age.

Ascending aneurysm is diagnosed in about half of all patients with thoracic aortic aneurysms. The pathology is known for frequent threatening complications that develop against the background of its natural course, is accompanied by increased mortality and therapeutic difficulties, requires special surgical skills.

The most common factors directly affecting the likelihood of complications are the localization and size of the aneurysm and the presence of background diseases (especially connective tissue pathologies). Studies show that the growth rate of aneurysmal enlargement can be 1 mm per year (for an aortic diameter greater than 35 mm). If the diametral size exceeds 50 mm, the growth rate increases to 5 mm per year. Against the background of the increase in the bulge increases on its wall: the probability of complications formation increases sharply.

A ruptured aneurysm becomes the most common cause of death. Over a five-year period, this figure is about 25-30%. The only way to reduce the incidence of complications and improve survival rates is to detect the problem as early as possible and timely surgical intervention.

Causes of the ascending aortic aneurysms

Specialists speak of the following pathogenetic aspects of the development of ascending aortic aneurysm:

• degenerative processes in the artery;
• connective tissue pathologies;
• Bicuspid aortic valve, aortic valve pathologies;
• infectious inflammatory processes;
• traumatic vascular injuries.

Among the most common genetically-associated causes:

• Marfan syndrome;
• Loeys-Dietz syndrome;
• Ehlers-Danlo syndrome;
• Takayasu disease (nonspecific aortoarteritis).

Other possible root causes include:

• atherosclerosis;
• syphilis;
• surgical interventions (catheterization sites or suture lines of the ascending aorta are at risk).

Risk factors

The most common risk factors for ascending aortic aneurysm formation include:

• increased blood pressure;
• age-related changes in the blood vessels;
• smoking, cocaine dependence (according to multiple data). [2]

Exposure of aortic walls to stressors, their damage and impaired extensibility lead to gradual aneurysm formation.

Degenerative changes in the aortic wall with preservation of normal valve mechanism and signs of aortic insufficiency due to disturbed stereometry of the arterial root skeleton are considered to be the basic etiologic factor in the development of ascending pathology. Such development of aortic insufficiency favors preservation of native aortic valve during aortic reconstructive surgery.

Pathogenesis

To date, the processes of aneurysm formation in the ascending aorta are not completely clear. Apparently, proteolytic enzymes, the so-called matrix metalloproteinases, which belong to the protease family that maintains the homeostasis of connective tissue, have an important pathogenetic significance. The basic metalloproteinases identified in the ascending aorta are gelatinase-A and gelatinase-B, which cleave type IV collagen, elastin and fibrillar collagen. These metalloproteinases are produced by individual cellular structures - in particular, smooth muscle cells. Their activity is controlled by tissue inhibitors of TIMPs - in particular, TIMP-1, which forms an irreversible connection with matrix metalloproteinases and is produced by fibroblasts and smooth muscle cells.

Another possible pathogenetic mechanism is due to degeneration of the media. The histopathologic picture is represented by Erdheim's disease, or cystic medianecrosis. The violation is diagnosed against the background of age-related changes in the arterial vessel, or connective tissue pathologies, bicuspid aortic valve. Increased intra-aortic pressure entails thinning of the intima, degradation of extracellular matrix, accumulation of proteoglycans, damage and loss of elastic fibers, necrosis of smooth muscle cells. As a result, the aorta becomes inelastic and its lumen widens.

According to experts, it is likely that both pathogenetic mechanisms are involved in the formation of ascending aneurysms. A special role is played by hereditary connective tissue pathologies - this is a large group of disorders, which consists, among others, of differentiated and undifferentiated syndromes (dysplastic phenotypes). [3]

Symptoms of the ascending aortic aneurysms

An aneurysm of the ascending segment does not always manifest itself in the same way. It depends mainly on the size of the bulge and its exact localization. In some patients, there is no clinical picture at all - at least until the development of a complication in the form of aneurysm rupture, although this is another diagnosis. The most common complaints are as follows:

• chest pain (cardiac or chest pain) due to the pressure of the aneurysm bulge on nearby structures, as well as the pressure of blood flow on the damaged vascular wall;
• dyspnea that tends to get progressively worse;
• The sensation of a heartbeat (heart "pounding");
• dizziness;
• seizure-like headaches (especially with large aneurysms);
• swelling of the face and upper body (caused by the development of superior vena cava syndrome).

When the pathologic process spreads to the aortic arch, other signs also join:

• difficulty swallowing due to compression of the esophagus;
• hoarseness, coughing, which is caused by compression of the recurrent nerve;
• increased salivation, decreased heart rate;
• pulmonary congestion, unilateral inflammatory processes in the lungs.

First signs

Aneurysm of the ascending section increases slowly, and often this process is asymptomatic, which greatly complicates the timely detection of the disease. Many cases of small pathologic dilations do not rupture during life. But the risks of rupture increase if the bulge is prone to constant increase, so it is important to pay attention to any unfavorable signs of pathology, in particular:

• unexplained chest pains;
• unexplained back pain (mainly between the shoulder blades).

If there is discomfort in the chest, unpleasant sensations in the heart area, if the closest relatives had cases of similar diseases or connective tissue pathologies, then it is necessary to visit a doctor without delay for a thorough diagnosis.

Forms

Currently, the division of ascending aortic aneurysms according to Belov is used:

1. Annuloaortic pathologic dilation.
2. Supraannular pathologic expansions.
3. Supravalvar, or supracommissural extensions.

In addition to this, distinguished:

1. true aneurysm, in which all layers of the arterial wall are stretched;
2. dissecting aneurysm (caused mainly by hereditary connective tissue abnormalities, arterial calcification, inflammatory processes);
3. A false aneurysm, in which there is an alleged wall bulge due to the accumulation of partially clotted blood on the outer vascular surface as a result of a traumatic injury.

• A dissecting aneurysm of the ascending aorta is a complication of an existing aneurysm in which blood penetrates between the layers of the aortic walls, completely dissecting them. Aneurysm of the ascending aorta with signs of detachment must be treated urgently, as it is a condition that literally threatens the patient's life: as a result of dissection, the arterial wall ruptures, there is rapid and massive blood loss, leading to death.
• When we talk about combined aneurysmal pathology, we usually mean that the pathologic enlargement has affected not one but two or more parts of the artery at once. Thus, aneurysms of the aortic root and ascending aorta are common: the aortic-fibrous ring, aortic valve flaps, the arch and sinuses of Valsalva, the schno-tabular junction up to the mouth of the brachiocephalic trunk are affected. In some cases, the ascending section is affected together with the aortic arch.
• Depending on the configuration, aneurysms can be sac-shaped (saccular) and spindle-shaped (fusiform). Fusiform aneurysms of the ascending aorta do not have a clear neck and can be quite large without early manifestation of symptoms.

Complications and consequences

The main and most threatening complication is a ruptured aneurysm of the ascending thoracic aorta, which leads to severe and life-threatening bleeding. The main signs of such a rupture can be:

• sudden onset of intense chest pain;
• irradiation of pain to the back, extremities;
• sudden dizziness, generalized weakness;
• lowering blood pressure readings;
• depression of consciousness, tachycardia;
• increasing numbness in the extremities, partial paralysis.

Among other possible complications, thrombosis and resulting thromboembolism are more common.

Postoperative complications are possible in the form of transient arrhythmias (supraventricular, ventricular), atrial fibrillation, bleeding, infectious and inflammatory processes, sometimes fatal outcome is possible - in particular, as a result of perioperative myocardial infarction.

Diagnostics of the ascending aortic aneurysms

The diagnosis of an ascending aneurysm begins with the collection of anamnesis and physical examination of the patient. Examination includes:

• palpation of the chest area, assessing the likelihood of connective tissue abnormalities;
• blood pressure measurement;
• assessment of neurologic status (check musculotendinous and cutaneous reflexes);
• detection of pathologic reflexes.

It is possible to involve subspecialists such as hematologists, geneticists, neurologists, oncologists, immunologists.

Tests are ordered as part of general laboratory investigations:

• hemogram (determination of inflammatory markers);
• general blood and urine analysis (to assess the general condition of the body);
• cytologic examination of cerebrospinal fluid obtained during lumbar puncture.

Instrumental diagnostics plays an important role in the diagnosis of ascending aneurysm. Previously, chest radiography in combination with aortography was considered the main method. Currently, invasive aortography is rarely used. It has been replaced by tomographic methods and echoCG. Nevertheless, the presence of aneurysmal enlargement can be suspected already on the radiograph. The picture in two projections provides a typical aortic visualization of the heart, which becomes an indication for the performance of other clarifying diagnostic procedures. Other signs include:

• dilated aortic shadow (optimally visualized in the left oblique projection);
• localized dilation in the ascending segment of the aorta;
• an altered shadow of the arterial or mediastinal configuration, compared to the values of the previous study;
• tracheal retraction.

Nevertheless, the "gold standard" in diagnostic terms remains echoCG, which allows to assess the morphology, functionality, etiologic aspects of the lesion, the state of the cardiac chambers, and coronary function.

Tomographic procedures (MRI, MSCT) help to thoroughly examine the area of dilation, to determine the diametric size, wall thickness, relationship to neighboring structures, the state of the coronary arteries, the presence of detachment, thrombi, and the length of the affected segment. Tomography makes it possible not only to correctly diagnose, but also to determine the surgical tactics, and further evaluate the results of surgery. [4]

Differential diagnosis

When a patient with suspected ascending aneurysm is admitted, first of all, separate life-threatening conditions such as acute coronary syndrome, pulmonary embolism, aneurysm dissection, spontaneous pneumothorax should be excluded. All these pathologies have an acute onset and are manifested by sharp pain in the chest, not eliminated by antianginal agents. The pain is accompanied by difficulty breathing, cyanosis, decreased blood pressure up to shock.

For the purpose of differential diagnosis, the following investigations are recommended:

• electrocardiography, echocardiography;
• chest radiography and/or computed tomography, magnetic resonance imaging;
• angiopulmonary angiography;
• esophagogastroduodenoscopy.

There are many diseases that present with similar symptoms. However, it is important to consider the likelihood of a particular pathology according to age and information obtained during history taking.

Treatment of the ascending aortic aneurysms

If the diagnosis of an ascending aneurysm is established without obvious progression of pathology, then doctors use conservative tactics followed by careful monitoring by vascular surgeons and cardiologists. Specialists monitor the general condition, blood pressure and ECG indicators. As therapeutic methods are applied:

• hypotensive therapy - to reduce the pressure of blood flow on the affected aneurysm wall;
• anticoagulant therapy - to prevent the formation of blood clots and further vascular thromboembolism;
• reduction of blood cholesterol levels - by taking hypocholesterolemic drugs and dietary correction.

Surgical intervention is applied in the presence of appropriate indications (they are described below), as well as in the development of life-threatening conditions (rupture of an aneurysm, etc.).

Drug treatment

The treatment regimen for ascending aneurysm is selected on an individual basis, based on the results of diagnostics. Presumably, drugs are prescribed:

• to reduce the severity of symptoms;
• to normalize blood cholesterol and fat metabolism;
• for general vascular strengthening;
• to normalize circulation;
• to improve blood composition and normalize blood coagulation processes.

Statins, fibrates, nicotinates, etc. May be used. Simvastatin, Rosuvastatin, Omacor, Fenofibrate, Enduracin, etc. Are prescribed as antiatherosclerotic drugs. Each of these drugs has side effects, so do not use them independently: it is important to consult a doctor who will compare the full information about the patient's condition and the existing picture of the disease.

The most common pain relievers for ascending aortic aneurysm:

• Dexketoprofen - 25 mg tablets - with prolonged use can worsen renal function, contributes to water retention in the body. The regimen is individual.
• Ibuprofen - 200-400 mg tablets - requires careful use, as it can cause irritation and erosion of gastric mucosa, development of allergic reaction (including in the form of bronchospasm).

The most popular remedies for lowering blood cholesterol concentrations:

• Simvastatin - prescribed in a starting dosage of 5-20 mg, with a further increase in the amount after a month. Tablets are taken in the evening, once a day. Possible side effects: digestive disorders, peripheral neuropathy, headache, dizziness, skin rashes.

Combinations of medications that have a pronounced hypotensive effect, allowing you to control blood pressure:

• RAAS inhibitor + diuretic;
• Renin-angiotensin system inhibitor + calcium channel blockers;
• renin inhibitor + angiotensin II receptor blocker;
• calcium channel blocker + diuretic;
• beta-adrenoblockers + diuretic;
• thiazide diuretic + potassium-saving diuretic;
• calcium channel blocker + beta-adrenoblocker.

Treatment should be constant, with systematic monitoring by a doctor and, if necessary, with medication correction. If conservative therapy is ineffective, or if there is a high risk of complications, surgery is used.

Surgical treatment

Surgeons use various valve-preserving techniques and operations in their practice. Let us consider the most common of them.

• Supracoronary prosthesis of the ascending aorta is appropriate for patients with concomitant aortic insufficiency due to dilatation of the sinotubular ridge. The method consists of excision of the ascending section at the level of the crest with further proximal anastomosis with a synthetic aortic prosthesis.
• Operative aortic valve resuspension (Wolfe) is used in case of dilation of the non-coronary sinus or aortic dissection with advancement to the non-coronary sinus. The artery is cut at the level of the sinotubular ridge, and the non-coronary sinus is dissected. If there is a dissection, U-shaped sutures are placed on the cusps, thus resuspending the aortic valve.
• Aortic valve reimplantation (David) eliminates the dilation of the valve fibrous ring, dilatation of the sinus of Valsalva and the sinotubular junction. During the operation, the disturbed stereometry of the aortic root is restored and its elements, including the aortic valve fibrous ring, are stabilized. This helps to prevent dilatation of the fibrous ring and the development of recurrent regurgitation.
• Aortic root remodeling (Yacoub) involves the use of a triple-bladed crown-shaped prosthesis in accordance with the sinuses of Valsalva. Fixation of the prosthesis is to the sides along the arch arches.
• Reimplantation of the aortic root into the implant consists in complete excision of the aortic root to the level of the aortic-ventricular junction and mobilization of the proximal segment of the coronary arteries. The operation allows remodeling and strengthening of the aortic root wall, stabilization of the valve fibrous ring and sinotubular ridge, with preserved stereometry of the aortic root elements.

Indications for surgery for ascending aortic aneurysm

The main indicative criterion for assessing the need for surgical intervention is the diameter of the aneurysm, as it is correlated with the risks of detachment or rupture of the aortic vessel. In general, the basic indications are considered to be as follows:

• diameter size of the arterial root is greater than 50 mm;
• The presence of Marfan syndrome or other genetic pathologies (Turner, Ehlers-Danlo, bicuspid aortic valve, familial aneurysms) even with smaller aortic diameters;
• diameter expansion of more than 5 mm per year;
• diameter size of the ascending section or root greater than 45 mm against the background of existing aortic insufficiency.

Diet for ascending aortic aneurysm

The diet of a person suffering from an aneurysm of the ascending aorta must necessarily include:

• all kinds of vegetables, fruits, herbs, berries;
• cereals, seeds, nuts;
• seafood;
• virgin vegetable oils.

Should be excluded:

• red meat, offal, sausage products;
• fast carbs, sweets, pastries;
• fatty foods, trans fats;
• salt, pickled and smoked foods.

When choosing dairy products, it is better to give preference to low-fat kefir, ryazhenka, natural yogurt, cottage cheese, hard cheese (fat content - up to 45%). The frequency of meals - 4-5 times a day, in portions of 150-200 g. It is important to drink a sufficient amount of clean water. Coffee and tea are undesirable. It is allowed instead of tea to drink a decoction of rose hips, infusion of chamomile or melissa. It is categorically not recommended to overeat!

People who follow a similar dietary regimen reduce their risk of developing aneurysm complications by about 30%.

Prevention

Recommendations in terms of preventing the development of ascending aneurysms are especially important for those who have a hereditary predisposition to pathology or an unfavorable epidemiological environment. To preserve their own health, it is necessary to adhere to a healthy lifestyle, and this applies to absolutely all people, even those who are not at risk.

Control the state of the vascular system can be achieved by such measures as dietary correction, therapeutic exercise, proper work and rest, reducing the amount of salt in the diet, eliminating smoking, normalization of body weight.

It is important to realize that eating food is not only about energy satiation or pleasure, but also about the introduction of various substances into the body - both vital and potentially dangerous. At high risk of developing an aneurysm of the ascending aneurysm should sharply reduce the part of animal fats in the diet. It is recommended to give preference to sea fish, products with fiber. It is undesirable that the menu contains butter, liver, egg yolks, lard. But the presence of oatmeal, vegetable oil, vegetables, greens is only welcome.

A lot of problems, including the development of aneurysmal pathologies, are caused by active and passive smoking. Just one pack of cigarettes daily increases the load on the cardiovascular system by 5 times. Nicotine contributes to an increase in blood pressure, negatively affects blood viscosity, aggravates the course of atherosclerosis. A person who got rid of a bad habit, reduces the factor of lethal outcome from cardiovascular diseases by 30-40%, regardless of the length of smoking or age. As for alcoholic beverages, their consumption should be minimized or eliminated altogether.

It is important to control body weight, avoid stressful situations and avoid hypodynamia. Moderate cardio exercises strengthen the cardiovascular system, and simple exercises can be performed even at home: breathing exercises, walking on the spot or running on the spot with knees raised high.

Another obligatory preventive point is systematic monitoring of blood pressure indicators. It is known that hypertension is one of the common risk factors for the development of ascending aneurysm and its further dissection.

It is important to see your doctor regularly:

• people over the age of 40;
• to smokers;
• patients with diabetes, obesity, hypertension, kidney disease, atherosclerosis;
• people living in unfavorable environmental conditions;
• living a passive lifestyle;
• who have a hereditary predisposition to pathologies of the cardiovascular apparatus.

Forecast

In the absence of the necessary therapeutic measures, the prognosis for patients with ascending aneurysms is unfavorable, as there is a high risk of rupture of the vascular walls or thrombosis. If the pathology was detected in time, and the patient underwent appropriate surgery, the prognosis can be called much more optimistic.

To improve the prognostic outcome, patients are recommended to undergo regular checkups with a cardiologist, neurologist. It is equally important to lead a healthy and moderately active lifestyle, control blood cholesterol levels, stop smoking, avoid hypodynamia and excessive physical exertion.

If there is aggravation of hereditary anamnesis - for example, if any of the relatives suffered from an aneurysm with or without rupture - it is necessary to repeat the examination twice a year (every six months), with mandatory ultrasound of the brain, ultrasound of the heart.

Aneurysm of the ascending aorta, which is characterized by intense enlargement, large size, has the maximum risk of complications and can be eliminated only by surgical intervention.