VPS common arterial trunk. Distinctive features of hemodynamics

What is the common truncus arteriosus

A physiological deviation in which the primitive trunk is not divided by a 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 human brain and lungs. The defect is manifested mainly by cyanosis, sweating, malnutrition and tachypnea. Diagnosis is by cardiac catheterization or echocardiography. In most cases, prevention of a disease such as endocarditis is necessary.

Among congenital heart defects, the common arterial trunk is, 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 departs from the trunk, then divides into the left and right pulmonary arteries.
Type II - the left and right pulmonary arteries depart independently from the posterior and lateral parts of the trunk, respectively.
Type III - the same as in type II.
Type IV - arteries depart from the descending aorta, provide blood to the lungs; this is a severe form of Fallot's tetralogy (as clinicians believe today).

The child may experience other anomalies:

anomalies coronary arteries
trunk valve insufficiency
double aortic arch
AV communication

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

What provokes / Causes of the Common truncus arteriosus

The common arterial trunk refers to congenital heart defects - 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 gestation. Among dangerous factors that provoke the disease, allocate diseases of the pregnant woman. Moreover, the unborn child is formed not only birth defects heart, and other life-threatening diseases.

Negatively affects the fetus, increasing the risk of a common arterial trunk in a newborn, chronic alcoholism mother. If a woman had rubella during pregnancy ( infectious disease), it with highly likely adversely affect fetal development. Among the negative factors are:

diabetes
flu
autoimmune diseases

The disease is provoked physical factors, often the effect of radiation. Such a factor can cause deformities and mutations of the fetus. This also includes beam methods research, a prime example- x-ray. Studies of this type should only be carried out in last resort better to use other research methods.

Harmful and chemical factors:

nicotine (smoking: active and passive)
alcohol intake
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 the main vessels on early stage embryogenesis (5-6 weeks of fetal development) and the absence of separation 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 the pulmonary artery, they are widely communicated. Because common trunk departs immediately from both ventricles, it mixes arterial and deoxygenated blood to the heart, lungs, liver and other organs of the child. The pressure is the same in the ventricles, arterial trunk and arteries of the lungs.

In most cases, there is a delay in the development of the walls of the heart, because the heart may consist of three or two chambers. The valve of the common arterial trunk can have one, two, three or four leaflets. IN frequent cases valve insufficiency or stenosis develops. Also, an extensive ventricular septal defect plays a role in the pathogenesis.

Symptoms of the common truncus arteriosus

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

malnutrition
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 such symptoms of the common arterial trunk:

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

On the left side of the sternum, a sound is heard systolic murmur intensity 2-4/6. At the apex, with an increase in blood flow in the pulmonary circulation, in some cases, noise is heard on mitral valve in the middle of diastole. With insufficiency of the valve of the arterial trunk, a decreasing diastolic murmur high tone. It is heard in the III intercostal space to the left of the sternum.

Diagnosis of the common arterial trunk

Diagnosis of common arterial valve in infants requires clinical data, as detailed above. X-ray data of organs are taken into account chest and data obtained from the electrocardiogram. Two-dimensional echocardiography with color Doppler cardiography helps to clarify the diagnosis. Before surgery, it is often necessary to clarify other anomalies that the patient may have, in addition to the disease in question. Then cardiac catheterization is performed.

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

The most relevant diagnostic methods

echocardiography- Echocardiography - a method that is a study of the heart using ultrasound. With a common arterial trunk, a direct connection of one or two pulmonary arteries with a single arterial trunk is revealed.

FKG- phonocardiography - a method for diagnosing diseases and pathologies of the heart. Murmurs and heart sounds are recorded on paper, which 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 increase in the right atrium, a slowdown in the conduction of the heart, an increase and overload of both ventricles.

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

Angiocardiography- radiography of the chest organs with contrast - allows you to detect specific changes in the vascular bed in patients with suspected common arterial trunk. An unusual or fuzzy structure of the roots of the lungs, depletion or increased pattern of the lungs, abnormal blood flow as a result of the detected defects are found. Both ventricles are enlarged and right atrium. This method is leading in terms of diagnosing such a pathology as the common arterial trunk in newborns.

Treatment of the common truncus arteriosus

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

The primary correction of the arterial trunk is surgical treatment. The ventricular septal defect is closed during surgery so that blood enters the arterial trunk only from the left ventricle. A channel 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 a common truncus arteriosus should adhere to preventive measures endocarditis before surgical interventions and a visit to the dentist, as bacteremia is likely to develop. 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 the pregnant woman:

avoid influence chemical factors including chemicals, medicines, narcotic substances and various alcohol
avoid the impact of adverse environmental conditions
in time to diagnose malformations in a child while he is still in the womb - this can be done by modern genetic diagnostic methods

The name of this rare heart defect defines its essence. Instead of two main vessels - the aorta and the pulmonary artery - one departs from the heart large vessel, carrying blood V big circle 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, it carries mixed blood into both circles of blood circulation (the ventricles communicate with each other through a huge defect of the interventricular septum). 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 the left depart directly from the trunk.

It is clear that with this defect, the entire circulatory system is deeply disturbed. In the ventricles, venous and arterial blood. This mixture, undersaturated with oxygen, enters the large circle and the lungs under the same pressure, and the heart works with a huge load. The manifestations of the defect become apparent 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 vessels of the lungs to increased blood flow leads to their changes, which will soon become irreversible. According to statistics, 65% of children with a common arterial trunk die within the first 6 months of life, and 75% do not live to see their first birthday. Patients, even those who have reached only two or three years of age, are 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 surgery in the first months of life. Delay in these cases is like death.

If for some reason the execution radical operation If it is impossible, then a palliative option exists and has justified itself: the imposition of a cuff on both pulmonary arteries extending 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, of course, under 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 with a conduit. The conduit is a synthetic tube of one or another diameter and length, in the middle of which a biological or (more rarely) mechanical prosthesis of the valve itself is sewn. We talked about 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 sutured conduit can sprout with its own tissue and collapse, and the valve can gradually overgrow and cope poorly 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 do not grow. And no matter how big the conduit is, in 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 it may take 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, prostheses will already be created, covered from the inside with their own cells, taken in advance from the tissues of the child. As long as 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 departs 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 CHD, 3% among critical CHD. The trunk has a single valve (truncal), on which there are from two to six valves (most often four), often with severe insufficiency. VSD in the vast majority of cases, is located directly under the valve. The trunk, as it were, "sits on horseback" over the defect, departing mainly from the right ventricle or into equally from both, and in about 16% of cases it is displaced 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, later it was proved that type IV refers to another pathology - pulmonary atresia.

Hemodynamics

natural flow

Hemodynamic disorders determine the degree of compromise pulmonary blood flow and ventricular overload. After birth, with the beginning of the functioning of the lungs, 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 by forcing 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 such a 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, heart failure is usually mild. But in these cases, arterial hypoxemia quickly occurs.

Rice. 26-13.

by R.W. Collette and J.E. Edwards. I - pulmonary arteries. depart from a short pulmonary trunk; II - the left and right pulmonary arteries depart separately: from rear wall trunk; III - one or both pulmonary arteries depart from the side walls of the trunk IV - the absence of pulmonary arteries, the blood supply to the lungs is carried out through the bronchial arteries extending from the descending part of the 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 blood flows through the lungs, corresponding to the norm. Volume overload of the ventricles and heart failure occurs only in case of insufficiency of the trunk valve.

In newborn children, the common arterial trunk in 90% of cases is accompanied by the development of critical conditions. About 40% of them die within the 1st week of life. By the end of the 1st year, remain alive
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 pulmonary blood flow restriction. The heart sounds are loud, the II tone is never split, since there is only one valve. Possible systolic murmur in the second or third intercostal space to the left of the sternum. With a large pulmonary blood flow, cardiomegaly and biventricular HF develop rapidly.

Instrumental research methods

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

X-ray of the chest organs. Enhanced pulmonary pattern is revealed. The shadow of the heart is moderately enlarged, vascular bundle narrow. certain diagnostic value has a high position of the left pulmonary artery. Approximately one third of patients have signs 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 found. The second semilunar valve is absent. Continuing the study, it is possible to trace the pulmonary arteries extending 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 CHD is determined (pathology of the aortic arch, its branches, coronary arteries, ASD, etc.).

Therapeutic treatment is ineffective, especially in semilunar valve insufficiency. Activities are aimed at reducing the metabolic needs of the body (thermal comfort, limiting physical activity child), a decrease in BCC (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 in separating the pulmonary arteries from the arterial trunk, connecting them to the right ventricle and closing the VSD.

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

Echocardiographic diagnostics tetralogy of Fallot is based on the detection of a ventricular septal defect in the area of the outflow tract and the location of the aortic root over the septal defect (aorta "sitting on the septum"). There is an inversion of the ratio between the diameter of the ascending aorta and the diameter of the pulmonary artery, and this disproportion is often significantly pronounced.

An important diagnostic sign is an enlargement of the aortic root. Doppler study of blood flow in such fetuses provides valuable information: detection of an increase in maximum systolic velocities in the trunk of the pulmonary artery confirms the diagnosis of Fallot's tetrad, since it indicates the phenomena of obstruction of the outflow tract of the right ventricle.

On the contrary, if color doppler mapping and pulse-wave Doppler in the trunk of the pulmonary artery is not recorded blood flow (antegrade or retrograde), this indicates atresia of the valve of the pulmonary artery.

Diagnostic problems occur with rare forms of changes observed in Fallot's tetrad. So, 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 trunk of the pulmonary artery 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 artefacts simulating the presence of a "overlay" of the aortic root on the septum. Incorrect transducer placement may give the false impression that there is no ventricular septal transition to the anterior aortic wall when examining a healthy fetus. The reason for the occurrence of this artifact is probably related to the angle of incidence of the ultrasonic beam.

Although in the series conducted In our surveys, 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 insonation angles, the use of color doppler and the search for other elements of the tetrad almost completely solves this problem.

In order not to miss possible related anomalies in the form of a common atrioventricular canal, the anatomy of the atrial-ventricular junction should be carefully assessed. The discovery of such a combination is associated with an increased risk of autosomal trisomies in this 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 the best timing surgical correction and evaluating its effectiveness, careful evaluation of other features such as multiple ventricular septal defects and coronary artery anomalies is also helpful. Unfortunately, at present, these changes cannot be reliably detected using prenatal echocardiography.

Heart failure never seen 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 pulmonary vascular network is supplied by the retrograde route 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, then cyanosis usually develops immediately after birth. With a lesser degree of obstruction of blood flow in it, cyanosis may not appear until the end of the first year of life. In cases of atresia of the trunk of the pulmonary artery, a rapid and pronounced deterioration in 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 "Diagnosis of heart defects and large vessels fetus":

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 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 survived the first year is extremely severe. Usually children are physically developed satisfactorily, but often they have a “heart hump”, cyanosis is observed during exercise, they are not very mobile. Arterial pressure is usually normal.

Data auscultation and FCG non-specific; I tone is normal, II tone in the second intercostal space to the left of the sternum is sharply increased, but it is never split. In many patients, a systolic murmur is heard at the left edge of the sternum, and in a significant part of them, a diastolic murmur of valve insufficiency OAS is also determined.

X-ray examination It is very characteristic, especially in type I defect: the heart is spherical, both ventricles are enlarged and hypertrophied. The vascular shadow of the main vessels is sharply dilated, and the branches of the pulmonary artery are equally dilated.

echocardiography makes it possible to see the main anatomical signs of the defect. It can be easily established that one main vessel departs from the heart. Moving the sensor in the direction of the main vessels, determine the place of origin of the pulmonary arteries from a single trunk, the diameter of their mouths. In cross section, the mouth of the OAS and the cusps of its valves are visible.

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

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

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

Treatment of the common arterial trunk Radical correction in OSA actually consists of three stages:

elimination of messages between the aorta and the pulmonary artery;
patch closure of a large VSD;
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 OAS is opened in the transverse direction and the aorta and pulmonary artery are separated by a patch. In fact, the surgeon must tightly close the mouth of the pulmonary artery.
the mouth of the pulmonary artery is cut off, and then the formed defect in the OSA 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 a 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 more optimal conditions. IN without fail the distal end of the anastomosis is sutured between the artificial trunk and the pulmonary artery. Hemming is carried out from the most distant part of the anastomosis towards the surgeon with a continuous suture. These sutures must be applied very carefully, since after the operation this section of the anastomosis is inaccessible to the surgeon's eye.

The next step is to sew the edge of the artificial trunk of the pulmonary artery with the anterior wall of the latter. Approximately half of the anastomosis is sutured between the proximal edge of the artificial pulmonary artery trunk and the ventricular wall. The needle is punctured through the prosthesis to the outside, the artificial pulmonary artery trunk is sutured to the anterior wall of the right ventricle.