VPS common arterial trunk. Distinctive features of hemodynamics

What is the Common Arterial Truncus -

A physiological deviation in which the primitive trunk is not divided by the septum into the pulmonary artery and aorta, while a large single truncus arteriosus. It is located above the perimembranous infundibular defect interventricular septum.

Due to this defect, mixed blood enters the systemic circulation, the brain and lungs of a person. The defect is manifested mainly by cyanosis, sweating, eating disorders and tachypnea. Cardiac catheterization or echocardiography is used for diagnosis. In most cases, prevention of a disease such as endocarditis is necessary.

Among congenital heart defects, the common truncus arteriosus accounts for, according to statistics, from 1 to 2% (among children and adults). More than a third of patients have palatocardiofacial syndrome or DiGeorge syndrome.

Four types of disease:

Type I - the pulmonary artery arises from the trunk, then divides into the left and right pulmonary arteries.
Type II - the left and right pulmonary arteries arise independently from the posterior and lateral sections of the trunk, respectively.
Type III - the same as type II.
Type IV - arteries arise from the descending aorta and supply blood to the lungs; this is a severe form of tetralogy of Fallot (as clinicians believe today).

The child may experience other anomalies:

anomalies coronary arteries
trunk valve insufficiency
double aortic arch
AV communication

These abnormalities increase the chance of death after surgery. In the first type of disease, the consequences include heart failure, slight cyanosis, and increased blood flow to the lungs. In the second and third types, a stronger expression of cyanosis is observed, and CH is observed in in rare cases, unlike the first type, and the pulmonary blood flow may be normal, or there will be a slight increase in it.

What provokes / Causes of the Common truncus arteriosus

Common truncus arteriosus is a congenital heart defect - it occurs when the fetus is in the womb. It can be caused by the effect on the body of a pregnant woman negative factors, especially in the first trimester of pregnancy. Among hazardous factors, provoking the disease, distinguish diseases of the pregnant woman. Moreover, the unborn child develops not only birth defects heart disease, and other life-threatening diseases.

Negatively affects the fetus, increasing the risk of truncus arteriosus in the newborn, chronic alcoholism mother. If a woman had rubella during pregnancy ( infectious disease), it with high probability will negatively affect the development of the fetus. Among the negative factors are:

diabetes
flu
autoimmune diseases

The disease is provoked physical factors, often this is the effect of radiation. This factor can cause deformities and mutations in the fetus. This includes radiation methods research, shining example- X-ray. Research of this type should only be carried out in as a last resort, it is better to use other research methods.

Harmful and chemical factors:

nicotine (smoking: active and passive)
drinking alcohol
part of medicines
drugs

Pathogenesis (what happens?) during the Common truncus arteriosus

The common arterial trunk appears due to a violation of the formation of great vessels on early stage embryogenesis (5-6 weeks of fetal development) and the absence of division of the primitive trunk into the main main vessels - the aorta and pulmonary artery.

Due to the absence of a normal septum between the aorta and pulmonary artery, they communicate widely. Because common trunk departs from both ventricles at once, arterial and deoxygenated blood to the heart, lungs, liver and other organs of the child. The pressure is the same in the ventricles, truncus arteriosus and pulmonary arteries.

In most cases, the development of the septum of the heart is delayed, so the heart may consist of three or two chambers. The valve of the common truncus arteriosus may have one, two, three or four leaflets. IN frequent cases valve insufficiency or stenosis develops. An extensive ventricular septal defect also plays a role in the pathogenesis.

Symptoms of the Common truncus arteriosus

In type I, the infant experiences symptoms of heart failure:

eating disorder
tachypnea
excessive sweating

Also typical symptom The first type of common truncus arteriosus is cyanosis in mild form. This and the above listed signs appear when the baby is only 1-3 weeks old. At II and III type cyanosis is more pronounced, and heart failure is observed in extremely rare cases.

Physical examination reveals the following symptoms of the common arterial trunk:

loud and single II tone and ejection click
increase in pulse pressure
increased heart rate

A sound can be heard along the left edge of the sternum systolic murmur intensity 2-4/6. At the apex, with an increase in blood flow in the pulmonary circulation, in some cases a murmur is heard mitral valve in mid-diastole. When the valve of the truncus arteriosus is insufficient, a decreasing sound is heard. diastolic murmur high timbre. It is heard in the third intercostal space to the left of the sternum.

Diagnosis of the Common truncus arteriosus

Diagnosis of common arterial valve in infants requires clinical data, which are described in detail above. X-ray data of organs are taken into account chest and data obtained from the electrocardiogram. Two-dimensional echocardiography with color Dopplercardiography helps to clarify the diagnosis. Before surgery, there is often a need to clarify other abnormalities that the patient may have, in addition to the disease in question. Then cardiac catheterization is performed.

X-ray methods make it possible to detect cardiomegaly (can be either slightly or strongly expressed), the pulmonary pattern is enhanced, the aortic arch is located to the right in a third of patients, the pulmonary arteries are located relatively high. With a significant increase in pulmonary blood flow, signs of left atrium hypertrophy may appear, which is also taken into account during diagnosis.

The most current diagnostic methods

EchoCG- echocardiography is a method that is a study of the heart using ultrasound. With a common truncus arteriosus, a direct connection of one or two pulmonary arteries with a single truncus arteriosus is identified.

FKG- phonocardiography is a method for diagnosing diseases and pathologies of the heart. The paper records murmurs and heart sounds that doctors cannot recognize with a stethoscope or phonendoscope. The method is used to confirm the diagnosis of the disease in question.

ECG- electrocardiography - allows you to detect an enlargement of the right atrium, a slowdown in cardiac conduction, an increase and overload of both ventricles.

Aortography — X-ray examination aorta and its branches using input contrast agent into the lumen of the aorta. The method is necessary to identify the level of trunk origin pulmonary artery, determining the state of the valve apparatus, etc.

Angiocardiography- X-ray of the chest with contrast - allows you to detect specific changes in the vascular bed in patients with suspected common truncus arteriosus. An unusual or unclear structure of the roots of the lungs, depletion or strengthening of the lung pattern, and abnormal blood flow as a consequence of the detected defects are detected. Both ventricles are enlarged and right atrium. This method is leading in terms of diagnosing such pathologies as the common arterial trunk in newborns.

Treatment of the Common truncus arteriosus

For the treatment of heart failure, which often accompanies common arterial valve, active therapy medicines. It is necessary to take digoxin, diuretics, ACE inhibitors. After a course of the drug, surgery is scheduled. Benefits intravenous infusion(infusion) of prostaglandin was not detected.

Primary correction of the truncus arteriosus consists of surgical treatment. During surgery, the ventricular septal defect is closed so that blood enters the arterial trunk only from the left ventricle. A conduit with or without a valve is placed between the origin of the pulmonary arteries and the right ventricle. Mortality during or after surgery ranges from 10 to 30%, according to statistics from the CIS countries and other countries of the world.

All patients diagnosed with truncus arteriosus should adhere to preventive measures endocarditis before surgical interventions and visiting the dentist, since there is a possibility of developing bacteremia. Bacteremia refers to the entry of bacteria into the blood. Bacteremia has serious consequences for the health and life of a person, especially a small child.

Prevention of the Common truncus arteriosus

Preventive measures are to minimize the impact of negative factors on a pregnant woman:

avoid influence chemical factors, including chemicals, medicines, narcotic substances and various alcohols
avoid exposure to unfavorable environmental conditions
diagnose developmental defects in a child in a timely manner while he is still in the womb - this can be done with modern genetic diagnostic methods

The name of this rare heart defect defines its essence. Instead of two great vessels—the aorta and the pulmonary artery—from the heart there is one large vessel, blood bearer V big circle blood circulation, to the lungs and coronary vessels. This vessel - the arterial trunk - did not divide, as it should, at 4-5 weeks of intrauterine life of the fetus, into the aorta and pulmonary artery, but “sitting” astride the two ventricles, carries mixed blood into both circles of blood circulation (the ventricles communicate with each other through huge ventricular septal defect). The pulmonary arteries to both lungs can depart from the trunk in one common vessel(and then split into branches) or separately, when both the right and left ones extend directly from the trunk.

It is clear that with this defect the entire circulatory system is deeply disturbed. In the ventricles the flows of venous and arterial blood. This oxygen-undersaturated mixture enters the systemic circle and the lungs under the same pressure, and the heart works with enormous load. Manifestations of the defect become obvious already in the first days after birth: shortness of breath, fatigue, sweating, cyanosis, rapid pulse, enlarged liver - in a word, all signs of severe heart failure. These phenomena may decrease in the first months of life, but in the future they will only increase. In addition, the response of the pulmonary vessels to increased blood flow leads to their changes, which will very soon become irreversible. According to statistics, 65% of children with a common arterial trunk die during the first 6 months of life, and 75% do not live to see their first birthday. For patients, even those who have reached only two or three years of age, it is usually too late to operate, although they can live up to 10-15 years.

Surgical treatment is quite possible, and its results are quite good. The most important a condition for success will be the timely admission of the child to a specialized cardiology center and performing the operation in the first months of life. Delay in these cases is like death.

If for some reason the execution radical surgery impossible, then a palliative option exists and has proven itself: applying a cuff to both pulmonary arteries arising from the common trunk. This operation (see the chapter on ventricular septal defects) will protect the pulmonary vessels from increased blood flow, but it must be done very early - in the first months of life.

Radical correction of the common arterial trunk is a major intervention, performed, naturally, in conditions cardiopulmonary bypass. The arteries leading to the lungs are cut off from the common trunk, thus turning the trunk only into the ascending aorta. Then the cavity of the right ventricle is dissected, and the septal defect is closed with a patch. The normal path for left ventricular blood has now been restored. The right ventricle is then connected to the pulmonary arteries using a conduit. A conduit is a synthetic tube of one or another diameter and length, in the middle of which a biological or (less often) mechanical prosthesis of the valve itself is sewn. We discussed the various designs of artificial valves and their disadvantages and advantages above (see the chapter on Ebstein's anomaly). Let's just say that as it grows, the entire sewn-in conduit can grow with its own tissue and be destroyed, and the valve can gradually become overgrown and poorly cope with its original function. In addition, the size of the conduit that can be sewn into a six-month-old child is clearly insufficient to work normally for many years: after all, synthetic tubes and artificial valves don't grow. And, no matter how large the conduit is, after a few years it will become relatively narrow. In this case, over time the question of replacing the conduit will arise, i.e. O reoperation, but this may happen after many years normal life child. However, the need for constant and regular cardiac monitoring should be obvious to you.

It is possible that by the time you read this, they will have already created prostheses coated on the inside with their own cells, taken in advance from the child’s tissues. For now it's only experimental work and it will take time for them to become a clinical reality. But with today’s dizzying pace of scientific development, this is quite possible in the near future.

CHD, in which one vessel arises from the base of the heart, providing systemic, pulmonary and coronary circulation. Another name for the defect is persistent truncus arteriosus. The frequency of pathology is 0.030.07 per 1000 live births, about 1.1% among all congenital heart disease, 3% among critical congenital heart disease. The trunk has a single valve (truncal), on which there are from two to six valves (most often four), often with severe insufficiency. In the vast majority of cases, the VSD is located directly under the valve. The trunk, as it were, “sits astride” the defect, extending primarily from the right ventricle or into equally from both, and in approximately 16% of cases is shifted towards the left ventricle.

Classification

The variety of forms of the common arterial trunk determines, first of all, the violation of the formation of the pulmonary arteries. In this regard, R.W. Collet: and J.E. Edwards (1949) identified four types of the common arterial trunk (I, I, III. IV) with several subtypes (Fig. 26-13). However, it was subsequently proven that type IV refers to another pathology - pulmonary atresia.

Hemodynamics

Natural course

Hemodynamic disturbances determine the degree of compromise pulmonary blood flow and ventricular overload. After birth, as the lungs begin to function, the resistance of the pulmonary vascular bed decreases, and pulmonary blood flow progressively increases. There is a sharp hypervolemia of the pulmonary circulation and volume overload of the left ventricle. The right ventricle, in turn, is forced to overcome systemic resistance, pumping blood into the common trunk, which is accompanied by its hypertrophy and dilatation. The volume load on the ventricles increases even more with truncal valve insufficiency. All this leads to the development of congestive heart failure. Due to the high pulmonary blood flow, blood oxygenation is not significantly impaired, s02 is 90-96%. However, the course of this variant of the defect is characterized rapid development high pulmonary hypertension. In the presence of narrowing of the pulmonary arteries, accompanied by normal or even reduced pulmonary blood flow, HF is usually mild. But in these cases, arterial hypoxemia quickly occurs.

Rice. 26-13.

by R.W. Collett and J.E. Edwards. I - pulmonary arteries. arise from the short pulmonary trunk; II - the left and right pulmonary arteries depart separately: from back wall trunk; III - one or both pulmonary arteries arise from the side walls of the trunk IV - absence of pulmonary arteries, blood supply to the lungs is carried out through the bronchial arteries originating from the descending aorta.

In prenatal period OSA does not significantly affect the condition of the fetus. There is an adequate systemic blood supply, and a small amount of normal blood flows through the lungs. Volume overload of the ventricles and HF occurs only in the case of truncal valve insufficiency.

In newborns, the common arterial truncus is accompanied by the development of critical conditions in 90% of cases. About 40% of them die within the 1st week of life. By the end of the 1st year there are still survivors
Clinical symptoms

By clinical manifestations the defect is similar to a large VSD. The first symptoms: shortness of breath, tachycardia. The degree of cyanosis varies depending on the degree of restriction of pulmonary blood flow. The heart sounds are loud, the second heart sound is never split, since there is only one valve. A systolic murmur is possible in the second or third intercostal space to the left of the sternum. With large pulmonary blood flow, cardiomegaly and biventricular HF quickly develop.

Instrumental research methods

ECG. Electric axis the heart is deviated to the right or located normally. In most cases, signs of combined overload of the ventricles and left atrium predominate. Isolated overload of the right or left ventricles is less common.

X-ray of the chest organs. An enhanced pulmonary pattern is revealed. The heart shadow is moderately enlarged, vascular bundle narrow. Certain diagnostic value has a high position of the left pulmonary artery. Approximately one third of patients have evidence of a right-sided aortic arch. With pulmonary artery stenosis, the vascular pattern of the lungs may be normal or reduced.

EchoCG. First of all, a large subarterial VSD and an enlarged, single vessel “riding” on it are detected. The second semilunar valve is missing. Continuing the study, you can trace the pulmonary arteries arising from the posterior or lateral wall of the arterial trunk. It is necessary to assess the condition of the truncal valve: the number of leaflets, the presence of their dysplasia, regurgitation or valve stenosis. It is also important to exclude hypoplasia of any of the ventricles. Subsequently, the presence of concomitant congenital heart disease (pathology of the aortic arch, its branches, coronary arteries, ASD, etc.) is determined.

Therapeutic treatment is ineffective, especially with semilunar valve insufficiency. The measures are aimed at reducing the metabolic needs of the body (temperature comfort, limiting physical activity child), decrease in blood volume (diuretics) and resistance of systemic vessels. However, as a rule, these measures are effective only for a short period of time. Patients with pulmonary artery stenosis respond better to therapy.

Various options for narrowing the pulmonary artery in order to reduce pulmonary blood flow are currently used only as a forced intervention. Most clinics perform radical correction defect starting from the neonatal period. The operation consists of separating the pulmonary arteries from the truncus arteriosus, connecting them to the right ventricle and closing the VSD.

12-23% of patients also require plastic surgery or replacement of the truncal valve due to its insufficiency.

Echocardiographic diagnostics Tetralogy of Fallot is based on identifying a ventricular septal defect in the area of the outflow tract and the location of the aortic root above the septal defect (the aorta “riding on the septum”). There is an inversion of the relationship between the diameter of the ascending aorta and the diameter of the pulmonary artery, and this disproportion is often pronounced.

Important diagnostic sign is an expansion of the aortic root. Doppler examination of blood flow in such fetuses allows one to obtain valuable information: identifying an increase in maximum systolic velocities in the trunk of the pulmonary artery confirms the diagnosis of tetralogy of Fallot, since it indicates obstruction of the outflow tract of the right ventricle.

On the contrary, if at color Doppler mapping and pulsed wave Doppler in the trunk of the pulmonary artery does not record blood flow (antegrade or retrograde), this indicates atresia of the pulmonary valve.

Diagnostic problems occur in rare forms of changes observed in tetralogy of Fallot. Thus, in cases of mild obstruction of the outflow tract of the right ventricle and small degree displacement of the aorta above the septum, it can be difficult to distinguish this condition from a simple VSD. And in cases where the pulmonary artery trunk is not visualized, it turns out to be just as difficult differential diagnosis between its atresia, accompanied by VSD, and the common arterial trunk.

Doctor ultrasound diagnostics should always be aware of common artifacts that simulate the presence of an “overlay” of the aortic root on the septum. Incorrect placement of the sensor may create a false impression that there is no transition of the interventricular septum into the anterior wall of the aorta when examining a healthy fetus. The cause of this artifact is likely related to the angle of incidence of the ultrasonic beam.

Although in the series carried out In our examinations, such an artifact led to only one false-positive conclusion; the experience of our subsequent work showed that careful visualization of the outflow tract of the left ventricle at different angles of insonation, the use of color circulation and the search for other elements of the tetrad almost completely solves this problem.

In order not to miss possible related anomalies as the common atrioventricular canal, the anatomy of the area where the atria connects to the ventricles should be carefully assessed. The detection of such a combination is associated with an increased risk of autosomal trisomies in a given fetus (especially Down syndrome), which in itself means a worse prognosis. Abnormal enlargement of the right ventricle, trunk, and right and left pulmonary arteries may result from agenesis pulmonary valve.

To select more optimal deadlines surgical correction and its effectiveness, careful evaluation of other features such as multiple ventricular septal defects and coronary artery anomalies is also useful. Unfortunately, these changes cannot currently be reliably detected using prenatal echocardiography.

Heart failure never observed in prenatal or early postnatal periods. Even in cases of severe stenosis or atresia of the pulmonary artery trunk, an extensive ventricular septal defect provides adequate overall cardiac output, and the network of pulmonary vessels is supplied in a retrograde manner through ductus arteriosus. The only exceptions to this rule occur in the presence of pulmonary valve agenesis, which can lead to massive regurgitation into the right ventricle and atrium.

If there is severe stenosis of the pulmonary artery trunk, then cyanosis usually develops immediately after birth. With a lesser degree of obstruction of the blood flow, cyanosis may not appear until the end of the first year of life. In cases of atresia of the pulmonary artery trunk, a rapid and pronounced deterioration of the condition in children occurs after the closure of the ductus arteriosus.

Educational video Ultrasound of the fetal heart is normal

Table of contents of the topic "Diagnostics of heart defects and large vessels fruit":

Cardiac surgery - Surgery.su - 2008

Common truncus arteriosus (CTA) called a defect in which one vessel departs from the base of the heart, providing systemic, pulmonary and coronary circulation.

Children are born in extremely difficult conditions, critical condition, and 85% of them die within the first weeks of life. Death occurs, literally, from pulmonary edema and severe uncontrolled heart failure. At an older age, the condition of patients who survive the first year is extremely difficult. Usually children are physically developed satisfactorily, but often they have a “heart hump”, cyanosis is observed during exertion, and they are not very mobile. Arterial pressure, as a rule, normal.

Data auscultation and FCG non-specific; The first sound is normal, the second sound in the second intercostal space to the left of the sternum is sharply intensified, but is never split. In many patients, a systolic murmur is heard at the left edge of the sternum, and in a significant proportion of them, a diastolic murmur of valvular insufficiency is also detected.

X-ray examination very typical, especially with type I defect: the heart is spherical, both ventricles are enlarged and hypertrophied. The vascular shadow of the great vessels is sharply expanded, and the branches of the pulmonary artery are equally expanded.

Echocardiography makes it possible to see the main anatomical signs of the defect. It can be easily established that one great vessel leaves the heart. By moving the sensor in the direction of the great vessels, the location of the pulmonary arteries from the single trunk and the diameter of their mouths are determined. In cross section, the mouth of the OAS and the leaflets of its valves are visible.

Cardiac catheterization. A probe from the right side of the heart is easily passed into the ascending aorta, i.e., into the OSA. In the right and left ventricles, in the aorta and pulmonary artery, the same systolic pressure. Only in exceptional cases when the mouth is narrowed pulmonary trunk pulmonary artery or its branches there is a pressure gradient. Blood oxygen saturation in OSA is high, however, it never reaches 96%.

Angiocardiography. When a contrast agent is introduced into the right ventricle, the passage through it and filling of the OAS are visible. Aortography is more informative. It is possible to see the level of origin of the pulmonary artery trunk, the size of the orifice, and in case of type II-III defect, the level of origin main branches pulmonary artery. The aortogram of OSA type I is characteristic. It is visible how both pulmonary branches depart from the OSA through the short trunk of the pulmonary artery.

Aortography is the only method that allows for intravital topical diagnostics various forms so-called atypical forms of OSA and identify valve insufficiency that often accompanies the defect.

Treatment of the common truncus arteriosus Radical correction for OSA actually consists of three stages:

elimination of communications between the aorta and pulmonary artery;
closure of a large VSD with a patch;
creation of an artificial pulmonary artery trunk using a valve-containing Dacron prosthesis.

First stage can be done in two ways

the wall of the OSA is opened in the transverse direction and the aorta and pulmonary artery are separated with a patch. In fact, the surgeon must tightly close the opening of the pulmonary artery.
the mouth of the pulmonary artery is cut off, and then the resulting defect in the pulmonary artery is sutured with a continuous suture.

Second phase. The right ventricle is opened at approximately middle third avascular zone, parallel to the long axis of the pulmonary artery trunk. The incision should not be made large, since the VSD with well-performed cardioplegia is clearly visible and it is not difficult to close it with a patch.

Third stage can be performed during cardiac fibrillation with the clamp removed from the aorta. However, reliable cardioplegia makes it possible to suture the prosthesis to the trunk of the pulmonary artery and the incision on the right ventricle in a more optimal conditions. IN mandatory the distal end of the anastomosis between the artificial trunk and the pulmonary artery is sutured. Stitching is carried out from the most distant site of the anastomosis towards the surgeon using a continuous suture. These sutures must be placed very carefully, since after the operation this area of the anastomosis is inaccessible to the surgeon’s eye.

The next step is to stitch the edge of the artificial trunk of the pulmonary artery to the anterior wall of the latter. Approximately half of the anastomosis is sutured between the proximal edge of the artificial trunk of the pulmonary artery and the wall of the ventricle. The needle is pushed out through the prosthesis and the artificial trunk of the pulmonary artery is sutured to the anterior wall of the right ventricle.