Common arterial trunk. Hemodynamics in the common truncus arteriosus

The common truncus arteriosus accounts for 1-4% of all congenital heart disease.

Anatomy

One great vessel with a single semilunar valve departs from the base of the heart and provides systemic, pulmonary and coronary circulation.

According to the classification of Collett and Edwards, there are 4 types of anomalies:

The main pulmonary artery arises from the trunk and then divides into right and left branches.

The left and right pulmonary arteries arise from back wall trunk Their mouths are located nearby.

Both pulmonary arteries arise from the lateral walls of the trunk.

The pulmonary arteries arise from the descending aorta.

The latter, or “false common truncus arteriosus” as it is called, is more of a severe form of tetralogy of Fallot with APA and aortic collaterals supplying the lungs. Types I and II account for 85% of all OSA. Van Praagh proposed a modified classification of OSA. Type A1 corresponds to type I of the Collett and Edwards classification, type A2 combines types II and III, since type III is extremely rare and from an embryological and surgical point of view they do not differ. Type A3 describes the absence of one pulmonary artery. The lung is supplied with blood through the ductus botallis or collateral vessels. According to the Mayo Clinic, one pulmonary artery is missing in 16% of patients, usually from the aortic arch. Type A4 represents a combination of OSA with a break in the aortic arch.

Pulmonary blood flow is increased in type I, remains normal in types II and III, and is reduced in type IV of the disease.

Directly below the trunk is a large perimembranous VSD, formed due to the absence or severe deficiency of the infundibular septum. The defect is surrounded by two branches of the septal pedicle and is adjacent to the truncus valves from above. In most cases, the fusion of the inferior ramus and the parietal pedicle forms a muscle mass that separates the tricuspid valve from the truncus valve. Thus, the membranous septum is intact. If fusion does not occur, there is contact between the tricuspid valve and the common trunk. In these cases, the defect occupies part of the membranous septum and the infundibular septum. Very in rare cases VSD in OSA can be small or even absent.

The truncus valve can have from two to four leaflets. In many cases the valves are thickened. Valve pathology manifests itself as insufficiency or stenosis and has a large clinical significance, as it affects the course and outcome of treatment. Stenosis occurs in a third of patients, and insufficiency occurs in half of patients. Anatomical reasons Truncus valve insufficiency is different:

thickening and nodular dysplasia of the valves;

sagging of unsupported sashes;

their fusion with superficial scars;

variety of valves;

commissural abnormalities and truncal dilatation.

OSA valve stenosis is usually caused by leaflet dysplasia. In this case, the sinuses of Valsalva are often poorly formed. The tricuspid valve structure is observed in 65-70% of patients. In 9-24% of cases, the valve consists of 4 leaflets and rarely - of 5 or more. The truncus valve can also be bicuspid or even single-leaf. The semilunar valve is in fibrous connection with the mitral valve in all patients and occasionally with the tricuspid valve. Hanging over the interventricular septum, OSA in 60-80% of cases arises from both ventricles, in 10-30% - completely from the right ventricle, and in 4-6% - from the left ventricle.

OSA is characterized by various anomalies coronary arteries in the form of stenosis of the orifices, high and low origin of the coronary arteries. The most common option is higher and rear location ostium of the left coronary artery near the ostia pulmonary arteries. In 13-18% of patients there is a single coronary artery. When the orifices are variable, the distal branches are usually normal. Sometimes there are large diagonal branches right coronary artery. They run parallel to and below the conus branch along the anterior surface of the right ventricle and therefore significantly complicate surgical correction vice. There are also anomalies of the coronary ostia, in particular, multiple holes in the intramural right coronary artery, opening into the pulmonary artery. The ostia of the coronary arteries may be narrowed or slit-like, which may cause poor coronary blood flow.

The most common associated defects are anomalies of the aortic arch. In 20-40% of patients, the aortic arch is right-sided, with a mirror origin of the brachiocephalic arteries. A double aortic arch is very rare. In 3% of patients, hypoplasia of the arch is observed with or without coarctation of the isthmus. Relatively common is a break in the aortic arch, in which the PDA continues into the descending aorta. Conversely, in 12% of patients, aortic arch rupture is accompanied by the presence of OSA. Typically there is a type B arc break - between the left common carotid artery and the left subclavian artery. This combination worsens the results of correction of these defects, so there should be a high degree of alertness at the preoperative stage. The common arterial truncus may be accompanied by the accessory left superior vena cava, PADLV, ATK, AVSD, and single ventricle of the heart.

Open ductus arteriosus in half of the patients it is absent. If a duct is present, it persists in two thirds of patients.

A third of patients with OSA and 68% of patients with type B aortic arch interruption are diagnosed with Di George syndrome. Patients with this syndrome have a specific appearance, they have hypoplasia thymus gland and aplasia parathyroid glands with hypocalcemia. Character traits individuals and the degree of dysfunction of the thymus and parathyroid glands vary. Cytogenetic studies revealed the absence of chromosome 22g 11. In addition to those listed clinical signs Some patients have cleft palate.

Hemodynamics

The dominant variant of blood circulation is the left-right discharge of blood at the level of the great vessels, if there is no narrowing of the mouths of the pulmonary arteries. The ratio of systemic and pulmonary blood flow depends on the resistance of the pulmonary and systemic vascular bed. Since PVR is increased in newborns, the defect does not manifest itself at first. As PVR decreases, pulmonary blood flow increases and symptoms of congestive heart failure develop. Increases pulse pressure as a result of blood leakage into the pulmonary artery during the diastole phase.

Saturation arterial blood oxygen depends on the volume of pulmonary blood flow. Due to severe pulmonary hypervolemia, SaO2 was reduced slightly - on average up to 90%. Without early correction of the defect, obstructive pulmonary vascular disease quickly develops.

The main hemodynamic disturbances are aggravated by the presence of stenosis or insufficiency of the truncus valve, which already in the newborn period is clinically manifested by a rough noise. Severe stenosis is accompanied by pressure overload of the ventricles, and valve insufficiency is accompanied by volume overload of the left ventricle. After a decrease in PVR, the left ventricle experiences a double volume overload, which is poorly tolerated by patients. In children with concomitant interruptions of the aortic arch systemic blood flow depends on the persistence of PDA. When it closes, cardiac output sharply decreases.

Clinic

Typical clinical manifestation The defect is congestive heart failure, which occurs in the first days or weeks after birth. Objective signs resemble VSD with PDA or aortopulmonary septal defect with VSD. Audible at medium intensity systolic murmur on the left edge of the sternum, ejection click and unsplit II sound. Sometimes you can hear proto diastolic murmur valve insufficiency and continuous noise in the presence of a pressure gradient between the trunk and branches of the pulmonary artery. In the hypervolemic stage of the disease, the peripheral pulse is high.

The ECG shows signs of biventricular hypertrophy. Isolated hypertrophy of the left or right ventricle is less common.

On the radiograph characteristic feature is cardiomegaly already at birth. The heart continues to enlarge as PVR decreases. The left atrium is dilated due to increased pulmonary venous return. The vascular pattern is enhanced, however, against the background of pulmonary congestion and edema, the silhouette of the pulmonary vessels may be blurred. It is necessary to identify the position of the aortic arch. Right-handed arc with an enhanced pulmonary pattern gives reason to suspect OSA. With narrowing or atresia of one of the pulmonary arteries, asymmetry of the vascular pattern is visible, sometimes in combination with pulmonary hypoplasia.

Echocardiography

Two-dimensional echocardiography and Doppler echocardiography allow precise determination of anatomical and hemodynamic details. It makes it possible to differentiate OSA from a patent aortopulmonary window, which is sometimes difficult to distinguish during an angiocardiographic study. The aortopulmonary window is usually not accompanied by VSD, and the right ventricular outflow tract is connected directly to pulmonary trunk. In case of truncus valve stenosis, Doppler echocardiography allows one to establish the magnitude of the pressure gradient and the severity of valve insufficiency using color echocardiography.

Cardiac catheterization and angiocardiography

Cardiac catheterization is performed to assess hemodynamic status, and angiocardiography allows us to determine what type of OSA a given patient has, clarify valve function and the anatomy of the coronary arteries. Due to the large leakage of blood into the pulmonary bed, it is usually necessary to high dose contrast agent to reveal anatomical details. In patients who have undergone surgery to narrow the pulmonary artery, be sure to perform detailed study coronary arteries, if necessary including selective coronary angiography. This is important because epicardial fusions during radical surgery make direct visualization of the coronary arteries and selection difficult free space to perform ventriculotomy and proximal conduit anastomosis.

Angiocardiography allows you to confirm the absence of one of the branches of the pulmonary artery, which may be suspected on an x-ray. In these patients, the corresponding lung is hypoplastic and cannot undergo surgical intervention. In patients with a break in the aortic arch, it is necessary to identify the break site in relation to the vessels extending from it. The condition of the aortic arch and the type of OSA are usually studied in anteroposterior and lateral projections.

A catheter inserted into the right ventricle records equal systemic pressure and high content oxygen. Then it easily passes into the OSA, arch and descending aorta. It is necessary to insert a catheter into both pulmonary arteries. The pressure gradient between the trunk and branches indicates the presence of stenosis at their mouths. Although both ventricles pump blood into the TSA, saturation in the pulmonary arteries may be lower than in the aorta due to the distribution of arterial and venous blood flows.

In OSA, obstructive pulmonary vascular disease develops early, so to exclude inoperability, PVR is calculated based on catheterization data.

It is difficult to assess the degree of truncus valve insufficiency during the administration of a contrast agent. Predominant leakage of blood into the pulmonary bed may mask valve insufficiency, therefore, if an angiocardiogram shows mild or moderate insufficiency, surgery may reveal severe valve incompetence requiring replacement. Doppler echocardiography has an advantage over angiocardiography in this regard.

Natural course

Without treatment, the prognosis is absolutely unfavorable. Although some patients experience childhood, most infants die between 6 and 12 months of life from heart failure. Longer life expectancy in patients with normal pulmonary blood flow. When obstructive pulmonary vascular disease develops, the condition of patients improves. These patients die in the 3rd decade of life. Truncus valve insufficiency progresses over time.

The defect occurs in 0.7-1.4% of children with congenital heart disease. In newborns, OSA is recorded with a frequency of 8-9 per 1000 (0.03-0.056%). The incidence of OSA is increased in children of mothers with diabetes (11 per 1000 births), and in premature infants and spontaneously aborted fetuses it reaches 5%.

Morphology
OSA is characterized by a single main artery, extending from the base of the heart, which provides systemic, pulmonary and coronary blood flow, and interventricular defect. Both of these anomalies arise due to septation disturbances during the development of the ventricular outflow tracts and proximal arterial segments of the heart tube. The common arterial trunk in 42% of patients is located above the interventricular septum, in another 42% it is displaced towards the RV, and in 16% towards the LV.

According to the classification of Collet and Edwards, the following types of OSA are distinguished: type 1 - a short trunk of the pulmonary artery departs from the common trunk immediately behind its valve to the left, type 2 - the main pulmonary artery is absent, and the right and left pulmonary arteries depart from the common arterial trunk behind and are located next to each other, type 3 - right and left pulmonary branches are significantly distant from each other and arise from the lateral surfaces of the common arterial trunk; type 4 - the pulmonary arteries arise from the descending aorta.

Classification by R. Van Praagh (1965) subdivides the vice in the following way: type A1 - a short trunk of the pulmonary artery departs from the common trunk on the left, type A2 - the right and left pulmonary arteries depart from the truncus separately, type A3 - only one pulmonary artery departs from the truncus (usually the right), and the other lung is supplied with blood through the ductus arteriosus or collateral vessels, type A4 - a combination of truncus with an interrupted aortic arch. The truncal valve is usually deformed and the leaflets are thickened, which is accompanied by its insufficiency. Very rarely it is stenotic. Typically, the truncal valve has 2 leaflets (60% of cases), less often - 4 leaflets (25%).

As a rule, the VSD is located in the anterosuperior part of the septum. Coronary anomalies also occur; among them, more often - the departure of both main coronary arteries a single trunk or the location of their mouths high above the coronary sinuses.

Hemodynamic disorders
The main hemodynamic disorder is a large left-to-right shunt, the volume of which increases towards the end of the neonatal period due to age-related decline pulmonary vascular resistance. For this reason, severe pulmonary hypertension occurs early.

Regurgitation on the truncal valve occurs in 50% of patients; it leads to overload of the right parts with excess pressure in addition to volume overload.

Time of onset of symptoms- first weeks of life.

Symptoms
Neonates with OSA show signs of congestive heart failure due to sharp increase volume of pulmonary blood flow and often the presence of truncal valve insufficiency. Characterized by tachycardia and severe tachypnea with retraction of the sternum and ribs, severe sweating, cyanosis, hepatomegaly, feeding problems (sweating, sluggish sucking, increased shortness of breath and cyanosis, poor weight gain). The severity of heart failure prevails over the severity of cyanosis in early appearance symptoms. Symptoms of HF increase parallel to the decrease in pulmonary vascular resistance after birth.

Pulsation of the heart area, left-sided cardiac hump and systolic tremor are often detected. The first heart sound has normal sonority, a systolic ejection click is heard, the second heart sound is amplified and not split. A persistent systolic murmur along the left sternal border is rarely heard and is caused by pulmonary stenosis or truncal pulmonary atresia in combination with a VSD or PDA or large aortopulmonary collaterals. With regurgitation on the truncal valve, a diastolic regurgitation murmur may additionally be heard.

Diagnostics
A frontal x-ray of the chest shows cardiomegaly, the vascular pattern is noticeably enhanced, and there is no shadow of the pulmonary artery.

On the electrocardiogram - sinus rhythm, signs of biventricular hypertrophy and LA hypertrophy. Signs of LV hypertrophy with a sharply increased pulmonary blood flow or RV hypertrophy with the development of obstructive damage to the pulmonary vessels may predominate.

Doppler echocardiography - using subcostal and parasternal access, signs of OSA arising from the ventricles are detected, with different types origins of the pulmonary arteries, deformation and thickening of the truncal valve leaflets, regurgitation on the truncal valve, signs of a large membranous VSD, anomalies of the coronary arteries. The morphology of the truncal valve and the origin of the coronary arteries can best be visualized from the parasternal long-axis view.

Despite topical verification of the defect during echocardiographic examination, cardiac catheterization and angiocardiography are still often required to clarify the type of OSA and the severity of pulmonary hypertension. An angiocardiographic study is indicated if there are additional defects in the structure of the heart or if it is necessary to clarify the details of the anatomy of the ventricles in cases where echocardiography suspects a general atrioventricular defect, underdevelopment of one of the ventricles, if only one pulmonary artery is visualized, or if an anomaly of the coronary arteries is suspected.

Laboratory data - decrease in SpO2 at rest to
Fetal diagnostics
During antenatal ultrasound examination The diagnosis is established more often within 24-25 weeks. The truncal valve usually connects to both ventricles, but sometimes it can be displaced predominantly towards one of the ventricles. In the case of atresia of one of the atrioventricular valves, the common arterial trunk arises from a single ventricle. Regurgitation of the truncal valve occurs in a quarter of patients; approximately the same proportion have stenosis of the truncal trunk. In a third of fetuses with this defect, additional defects in the structure of the heart can be seen, such as the right aortic arch, interruption of the aortic arch, tricuspid atresia, mitral atresia, dextrocardia, total anomalous drainage of the pulmonary veins. Extracardiac abnormalities occur in up to half of fetuses with OSA, including 22q11 microdeletions (including manifestations of DiGeorge syndrome, with thymic hypoplasia or aplasia).

Natural evolution of vice
In patients who did not receive surgical treatment, an unfavorable outcome occurs in the first half of life in 65% of cases, and by 12 months - in 75% of cases. Some patients with relatively balanced pulmonary blood flow can live up to 10 years and sometimes longer. However, they tend to have severe heart failure and pulmonary hypertension.

Observation before surgery
Most infants suffer from persistent severe heart failure and progressive malnutrition, despite treatment with digoxin, diuretics and ACE inhibitors.

Timing of surgical treatment
If the operation is performed between 2 and 6 weeks of life, the chances of survival are highest.

Types of surgical treatment
Pulmonary artery banding is ineffective.

In 1968, the first report of successful radical correction OSA performed by D. McGoon based on the experimental development of G. Rastelli on the use of a valve-containing conduit connecting the ventricle and the pulmonary artery. The first successes of surgical correction were achieved in older children, which prompted other surgeons to delay the operation. However, many children did not live to this point and were not able to achieve the desired weight and height. Later, in 1984, P. Ebert et al. reported excellent early and late results of radical repair of the truncus arteriosus in infants less than 6 months of age. Then a number of surgeons achieved the same results even with simultaneous reconstruction of the truncal valve or valve replacement if necessary, after which early surgical correction of OSA was recommended to prevent decompensation of heart failure, severe pulmonary hypertension and cardiac cachexia in young patients. In the last 10-15 years, OSA has been operated on in the neonatal period (after the 2nd week) with low level mortality (5%) and a low number of complications. The operation consists of complete correction with plastic surgery of the VSD, connection of the truncus to the LV and reconstruction of the outflow tract of the pancreas.

In patients with the right and left pulmonary arteries arising directly from the pulmonary artery, reconstruction of the pancreatic outflow tract can be performed using a valve-containing conduit. To restore the connection of the pancreas with the pulmonary arteries, it is possible to use a cryopreserved valve-containing aortic or pulmonary allograft or a pulmonary graft made of synthetic materials, or using an autovalve, a porcine xenoconduit, or a bovine jugular valve.

If one pulmonary artery arises from the truncus and the other from the lower part of the aortic arch, both of them are disconnected from these areas separately, then connected together and then anastomosed to the conduit or separately to the conduit.

Results of surgical treatment
According to a number of clinics, in the 60-70s. XX century survival rate after radical correction was 75%, and in the period 1995-2003. - up to 93%. Modern techniques significantly improved the prognosis of patients. Physiological basis improvement of the results of surgical treatment with an early approach is the absence of complications from long-term severe heart failure and hypervolemia of the pulmonary circulation at the time of surgery. Aggressive tactics of truncal valve repair instead of replacing it in the presence of valve dysfunction and an individualized approach to reconstruction of the pancreatic outflow tract also help improve postoperative outcomes. Body weight significantly influences the outcome of the correction - the worst survival rate is for children weighing less than 2500 g who require valve replacement. Currently, perioperative mortality in the world is 4-5% with surgical correction at the age of 2-6 weeks.

Postoperative follow-up
Observations have shown that homografts, in comparison with Dacron conduits containing pork valve, are characterized best result surgical correction in infants, less postoperative bleeding and better survival after surgery. All homografts with a valve size less than 15 mm require replacement after 7 years. When the homograft valve size is more than 15 mm, replacement after 10 years is required only for 20% of patients.

After successful reconstructive surgery for OSA, children need careful postoperative observation with assessment of potential aortic (truncal) insufficiency and conduit function between the pancreas and the pulmonary artery. Subsequently they will need at least two more reconstructive operations to replace the conduit, with artificial circulation.

Although late postoperative mortality in patients who have undergone early surgical correction, it is minimal; it may be associated with the occurrence of problems in the condition of the pancreatic outflow tract in connection with the reconstruction performed (the need to replace the conduit, revision or dilatation). In 64% of children without risk factors, freedom from reoperations is observed by the age of 7 years, and in 36% of children with risk factors - by the age of 10 years.

The survival rate of children operated on in leading cardiac surgery centers reaches 90% 5 years after surgery, 85% after 10 years and 83% after 15 years. There is also evidence that in infants up to 4 months of age, freedom from reinterventions associated with the condition of the conduit is observed in 50% of cases.

Due to the development of new biotechnologies in the future, the intervals between operations should increase, and the number potential complications decrease.

Conditions caused by birth defects are life-threatening. They are fraught critical conditions. The common arterial trunk is a pathology that experts classify in the first category in terms of severity.

Early diagnosis, preferably still in perinatal period, will allow you to prepare well for providing assistance and plan it carefully. This approach will improve the patient's prognosis for solving the problem. So, let's figure out that this is an anomaly of the circulatory system, the common arterial trunk.

Features of the disease

Incorrect structure: instead of two highways emanating from each ventricle, there is one arterial trunk, which receives blood from the ventricles, where it mixes. The line is most often located above the septum at the site of its defect.

During the perinatal period, the child does not suffer from abnormal abnormalities in the structure of the heart. After birth it acquires a bluish coloration skin, other symptoms also develop: shortness of breath, sweating.

The body experiences oxygen starvation. Right half the heart is overloaded, because due to the communication of the ventricles, the same pressure is obtained in them.

By nature, the right ventricle is designed to low blood pressure. Due to the pathology, pressure is created in the pulmonary vessels, and they develop resistance, which can pose a threat to life.

You can help your child if you correct the pathology surgically in time. If left untreated, the prognosis is poor.
Over time, irreversible processes in the lungs make corrective surgery impossible. In this case, a lung and heart transplant can save you.

Diagram of the development of the common arterial trunk

Forms and classification

The location of the pulmonary artery, including its branches, is determined different shapes pathology.

1. The right and left pulmonary arteries are located from the back of the trunk. They come out of a common trunk and are located next to each other.
2. The pulmonary arteries are attached to the trunk, located on the sides.
3. The trunk is divided into the aorta and the short pulmonary artery. The right and left arteries emerge from the pulmonary common vessel.
4. When there are no pulmonary arteries, and the lungs are supplied with blood through the bronchial arteries. Experts now do not classify this pathology as a type of common truncus arteriosus.

Causes

The defect develops in a child during his perinatal life. In the first three months, cardiac detailing occurs vascular system. This period becomes the most vulnerable for harmful influences, which can contribute to the appearance of anomalies.

TO harmful factors during pregnancy include:

• exposure to radiation,
• nicotine,
• contact with harmful chemicals,
• alcohol, narcotic substances;
• taking medications must be done after consultation with a specialist;
• Improper organ formation can happen if expectant mother during pregnancy will get sick:
  • flu,
  • autoimmune diseases,
  • rubella,
  • other infectious diseases;
• Diabetes mellitus is a dangerous chronic disease; a pregnant woman suffering from this disorder must be under close supervision of an endocrinologist.

Symptoms

The defect creates a situation of chronic lack of oxygen in the blood. This shows up in symptoms.

The patient experiences:

• sweating,
• there is a significant increase in breathing, especially when the load on the body increases;
• the skin has varying degrees, depending on the depth of the problem, bluish color,
• decreased tone,
• the spleen and liver may become enlarged,
• the child begins to noticeably lag behind in physical development,
• increased size of the heart can provoke deformation of the chest in the form of a cardiac hump,
• there may be a change in the shape of the fingertips, their thickening;
• the pathology causes deformation of the nails in the form of “watch glasses”.

Diagnostics

A newborn may already have expected health problems if fetal examinations have been carried out. Early diagnosis allows you to prepare and plan help for your child in advance.

If a newborn has symptoms: fatigue, shortness of breath, cyanosis, then the specialist will prescribe a clarifying examination. This may include procedures:

• Phonocardiography - a device that records heart sounds on paper. Gives precise definition, whether there are any disturbances or noises in them. Clarifies those tones that cannot be heard with a stethoscope.
• Electrocardiography - provides information about whether there is an enlargement of the chambers of the heart, whether there is an overload in their work, and reveals changes in conductivity.
• Aortography is an examination of the structure of the aorta. A special contrast agent is injected into it, which identifies itself during an X-ray examination of the line. Informative method.
• X-ray – an examination of the chest. Often the procedure is supplemented with the use of a contrast agent, which makes it possible to see the pulmonary pattern and details of disturbances in the functioning of the ventricles. This method is necessarily used to diagnose this defect.
• Catheterization - equipment is inserted into the heart area using a catheter, transmitting full information about the structure and anomalies of internal structures.
• Echocardiography is a safe method and provides valuable information about the structure of the great vessels and the septum between the ventricles.
• Tests - blood and urine tests will help you understand general state body and determine whether there are other pathologies.

Treatment

The main method of helping patients with the common truncus arteriosus is surgery. All other procedures are aimed at maintaining normal condition before or after surgery.

Therapeutic and medicinal methods

Patients who have been diagnosed with pathology " common trunk", must follow the recommendations of specialists to avoid inflammation of the membranes of the heart.

Before surgery, diuretics and glycosides are used. They provide relief to symptomatic newborns. This can only be a temporary measure.

Operation

The narrowing of the branches arising from the pulmonary artery improves big picture illness, and provide an opportunity to postpone radical intervention. Therefore there is palliative surgery, which solves the problem of ligation of the pulmonary arteries.

The main method to fix the problem is open surgery. Intervention is needed to correct congenital anomalies, dividing the common trunk into two mains. The septal defect, which almost always accompanies this type of defect, is also reconstructed.

Prosthetics are often used to perform the task. As the child grows up, the existing prosthesis needs to be replaced with a larger device.

Modern medicine has learned to perform corrective operations without prior palliative intervention. But this is if the patient’s condition allows.

There are cases when a child cannot be operated on. This applies to patients whose pulmonary vascular resistance is increased. They are born with more pronounced cyanosis. It will be possible to help such children after some time by performing lung and heart transplants.

The following video will show, using an example, what the operation-correction of the common arterial trunk consists of:

Disease prevention

While carrying a child, a woman should protect herself as much as possible from negative factors:

• not to be in an area of ​​unfavorable ecology,
• do not be exposed to harmful chemicals,
• take carefully medicines, consult a doctor;
• stop drinking alcohol and eliminate it from your habits,
• do not expose yourself to ionizing radiation,
• be observed by specialists, so that if the fetus has a common truncus arteriosus, gain time to help him through an early diagnosis.

Complications

It is important to identify the disease as early as possible in order to have time to prepare the patient for surgery and carry it out. High blood pressure in the right ventricle is not typical for it. It occurs due to the fact that there is a communication between arterial and venous blood, and the pressure in the ventricles is equalized.

Increased pressure in the pulmonary vessels causes a resistance response, which initiates pulmonary hypertension. This is an irreversible process in which no corrective surgery is performed. The situation is life-threatening; only a lung and heart transplant can help.

Forecast

If corrective surgery is performed on time, the prognosis is usually positive. You should be observed for a long time by a specialist and, as you age, replace the ones sewn into your early childhood prostheses.

Special case: common truncus arteriosus and right ventricular hypoplasia

Congenital defects can also occur in combination with each other. So, if the described pathology is also loaded with reduced dimensions, then the tension in it may be unnaturally increased.

And the common trunk makes it possible to discharge venous blood and somewhat reduce the tension in right side. The transfer of venous blood increases cyanosis. Urgent surgery is required to prevent irreversible phenomena from occurring.

Truncus arteriosus (TCA) is a disorder of the heart, characterized by a high degree of severity and congenital nature. This condition is expressed in the fact that only one, not divided, leaves the heart muscle blood vessel. OSA is diagnosed in 2-3% of cases, and always in parallel with another disorder that extends to the area interventricular septum.

The common truncus arteriosus is a deviation expressed in the combination of the pulmonary artery and aorta into one. The disorder occurs when the fetus develops in the mother's body. It connects the arterial and deoxygenated blood, penetrating into both circles of blood circulation.

A deviation of this nature is diagnosed in newborns. The condition is very dangerous and can cause death if assistance is not provided in a timely manner, as it causes a constantly developing dysfunction of most body systems.

OSA is localized over the ventricles in two variants: over both or only over one of them.

The formation of OSA in most cases is preceded by other anomalies: a single ventricle, as well as some disturbances in the functioning of the aorta.

The common arterial truncus in a newborn is 75% a factor in the mortality of the newborn even before he turns one year old. In 65% of cases, death occurs before the age of six months.

High level mortality in OSA is due to severe. Excessive filling of the pulmonary vessels with blood also plays a significant role. In addition, with this disorder, the body experiences acute oxygen starvation.

Reasons for rejection

This heart defect is formed during the period when the fetus develops in the mother’s body. Dangerous period– the first trimester, when formation occurs of cardio-vascular system.

The common arterial trunk in a child is the result of the following reasons:

• radiation effects on the body of a pregnant woman;
• exposure to infections (viruses) that have affected the pregnant woman’s body during initial stages fetal development;
• undergoing X-ray examinations by a pregnant woman;
• reception alcoholic drinks a woman who bears a fetus;
• autoimmune diseases pregnant women, which cause a conflict between the organisms of the woman and the fetus;
• influence toxic substances;
• interaction with chemicals;
• diabetes;
• uncontrolled use of medications.

This is far from full list reasons causing the formation of OSA: scientists have not yet come to a conclusion general opinion regarding all factors that can provoke severe pathology.

How is pathology classified?

There are 4 types of deviation. The variety depends on the site of origin of the pulmonary arteries, when one of the scenarios occurs:

• the vessel, separating from the common trunk, is divided into the left and right pulmonary arteries;
• each artery is separated from the posterior wall of the common trunk;
• they extend from the side walls of the trunk;
• There are no arteries, and the lungs fill with blood through arteries that arise from the aorta.

The specific type of disease is determined during diagnostic studies.

Distinctive features of hemodynamics

In the presence of a common arterial trunk, the fetus experiences pronounced disturbances: when the structure changes, instead of two highways emanating from each ventricle, there is only one trunk, to the area of ​​which blood flows from the ventricles.

The right half of the heart muscle in OSA is overloaded, since due to the communication of the ventricles, the same pressure is observed in them.

Under normal conditions, the pressure in the right ventricle is low. In the case of the common truncus arteriosus, pressure arises in the pulmonary vessels, which in turn provide resistance. This poses a threat to life.

In the case of OSA, 3 types of hemodynamic disturbances are observed:

1. An increase in the volume of pulmonary blood flow and an increase in pressure in the vessels of the lungs. As a result, the pressure in the lungs increases and heart failure occurs. These phenomena are resistant to treatment.
2. An insignificant increase in pulmonary blood flow or normal, not too pronounced blood ejection. In this case, there is no heart failure; cyanosis is observed during exercise.
3. Reduced pulmonary blood flow due to stenosis of the pulmonary artery. Regular cyanosis is observed.

There are two main types of operations:

• Palliative. This is an intervention that temporarily alleviates the patient’s condition, but does not completely eliminate the pathology. In this case, a special clip is applied to the pulmonary artery, which narrows the lumen of the vessel and thus corrects the discharge of blood into the general channel.
• Radical, that is, completely eliminating the pathology. The correction includes three stages. First, the communication between the aorta and the pulmonary artery is stopped, then the atrial septal defect is closed using a patch. Next, an artificial trunk of the pulmonary artery is created. To do this, they resort to using a trunk stent.

This type of intervention is difficult, as it is carried out on open heart. In this case, the device is used cardiopulmonary bypass.

If positive dynamics are observed after surgery, the patient must regularly take medications that regulate blood flow.

Forecast

Is it possible for an infant diagnosed with OSA to survive? If surgery is not performed on time, death will inevitably occur within the first year of life.

The outcome is successful if the deviation does not cause pronounced changes in the pulmonary vessels.

If the operation is successful, the child remains alive. In the future, regular medical control and reception special drugs.

Mortality during or after surgery ranges from 10 to 30%.

Prevention

The main measures to prevent the development of pathology are to protect the pregnant woman from harmful influences as much as possible. This applies to the influence of radioactive and any harmful substances, alcohol, nicotine, various toxic substances. It is important that there are no virus carriers in the woman’s environment.

OSA is a rare but dangerous pathology that spreads to the heart muscle and causes a large number of deaths of infants who do not survive to 12 months. Timely diagnosis and treatment leave a chance for the child to survive.

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 arterial trunk is formed. It is located over the perimembranous infundibular ventricular septal defect.

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:

• coronary artery anomalies
• 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 HF is observed in rare cases, in contrast to 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 influence of negative factors on the pregnant woman’s body, 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 (an infectious disease) during pregnancy, this is 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. Therefore, the common trunk extends immediately from both ventricles, in which arterial and venous blood is mixed to the heart, lungs, liver and other organs of the child. The pressure is the same in the ventricles, truncus arteriosus and arteries of the lungs.

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 pathogenesis.

Symptoms of the Common truncus arteriosus

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

• eating disorder
• tachypnea
• excessive sweating

Also, a typical symptom of 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 holosystolic murmur of intensity 2-4/6 is heard along the left edge of the sternum. 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. With truncus arteriosus valve insufficiency, a decreasing high-pitched diastolic murmur is heard. 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. Chest x-ray data and electrocardiogram data are taken into account. 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 of the aorta and its branches by introducing a contrast agent into the aortic lumen. The method is necessary to identify the level of origin of the pulmonary artery trunk, determine the condition of the valve apparatus, etc.

Angiocardiography- chest x-ray with contrast - allows you to detect specific changes in vascular bed in patients with suspected 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, and 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 visits to 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, drugs, 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