Common arterial trunk. Hemodynamics in the common arterial trunk

The common truncus arteriosus accounts for 1-4% of all CHD.

Anatomy

One main 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 departs from the trunk and then divides into the right and left branches.

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

Both pulmonary arteries depart from the side walls of the trunk.

The pulmonary arteries arise from the descending aorta.

The latter variant, or "false common truncus arteriosus" as it is called, is more of a severe tetralogy of Fallot with ALA and aortic collaterals supplying the lungs. Types I and II account for 85% of all OSA. Van Praagh has proposed a modified classification of OAS. 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 arteriosus or collateral vessels. According to the Mayo Clinic, one pulmonary artery is absent in 16% of patients, usually on the side of the aortic arch. Type A4 represents a combination of OSA with interrupted aortic arch.

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

Directly under 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 stalk and adjoins the valves of the trunk from above. In most cases, the fusion of the inferior branch 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. In very rare cases, VSD in OSA may be small or even absent.

Trunkus valve can have from two to four leaflets. In many cases, the valves are thickened. Valve pathology is manifested by insufficiency or stenosis and is of great clinical importance, as it affects the course and outcomes of treatment. Stenosis occurs in a third of patients, and insufficiency - in half of patients. The anatomical causes of truncus valve insufficiency are different:

thickening and nodular dysplasia of the valves;

sagging of unsupported sashes;

their fusion with superficial scars;

variability of valves;

commissural anomalies and dilatation of the truncus.

OSA valve stenosis is usually due to leaflet dysplasia. 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. Trunkus valve can also be double-leaf and even single-leaf. The semilunar valve is in fibrous communication with the mitral valve in all patients and rarely with the tricuspid valve. Hanging over the interventricular septum, OSA in 60-80% of cases departs from both ventricles, in 10-30% - completely from the right and in 4-6% - from the left ventricle.

OSA is characterized by various anomalies of the coronary arteries in the form of stenosis of the mouths, high and low discharge of the coronary arteries. The most common variant is a higher and posterior location of the orifice of the left coronary artery near the orifices of the pulmonary arteries. In 13-18% of patients, a single coronary artery occurs. With orifice variability, the distal branches are usually normal. Large diagonal branches of the right coronary artery are sometimes observed. They run parallel and below the conical branch along the anterior surface of the right ventricle and therefore greatly complicate the surgical correction of the defect. There are also anomalies of the coronary mouths, in particular, multiple holes in the intramural right coronary artery, opening into the pulmonary artery. The orifices of the coronary arteries may be narrowed or slit-like, which may be the reason for the deterioration of coronary blood flow.

The most common concomitant defects are anomalies of the aortic arch. In 20-40% of patients, the aortic arch is right-sided, with a mirror discharge 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, interruption of the aortic arch is accompanied by OSA. Usually there is a type B break of the arc - between the left common carotid artery and the left subclavian artery. This combination worsens the results of the correction of these defects, so there should be a high degree of alertness at the preoperative stage. The common arterial trunk may be accompanied by an additional left superior vena cava, FADLV, ATK, AVSD, the only ventricle of the heart.

An open ductus arteriosus is absent in half of the patients. In the presence of a duct, it persists in two-thirds of patients.

One third of patients with OSA and 68% of patients with type B aortic arch rupture are diagnosed with Di George syndrome. Patients with this syndrome have a specific appearance, they have hypoplasia of the thymus and aplasia of the parathyroid glands with hypocalcemia. Characteristic features of the face and the degree of dysfunction of the thymus and parathyroid glands vary. Cytogenetic studies revealed the absence of chromosome 22g 11. In addition to the listed clinical signs, some patients have a cleft palate.

Hemodynamics

The dominant variant of blood circulation is the left-right shunt of blood at the level of the great vessels, if there are no narrowings of the orifices of the pulmonary arteries. The ratio of systemic and pulmonary blood flow depends on the resistance of the pulmonary and systemic vascular beds. Since PVR is elevated in newborns, the defect does not manifest itself at first. As PVR decreases, pulmonary blood flow increases and symptoms of congestive heart failure develop. Pulse pressure increases as a result of blood leakage into the pulmonary artery during diastole.

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

The main hemodynamic disorders are aggravated by the presence of stenosis or insufficiency of the truncus valve, which are clinically manifested by coarse noise already in the neonatal period. Severe stenosis is accompanied by an overload of the ventricles with pressure, valve insufficiency is accompanied by a 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 the PDA. When it closes, cardiac output drops sharply.

Clinic

A typical clinical manifestation of the defect is congestive heart failure that occurs in the first days or weeks after birth. Objective findings resemble a VSD with a PDA or an aortopulmonary septal defect with a VSD. Medium-intensity systolic murmur along the left edge of the sternum, an ejection click and an unsplit II tone are heard. Sometimes a protodiastolic murmur of valve insufficiency and a continuous murmur is heard in the presence of a pressure gradient between the trunk and branches of the pulmonary artery. In the hypervolemic stage of the defect, the peripheral pulse is high.

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

On the radiograph, a characteristic feature is cardiomegaly already at birth. The heart continues to increase as the 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. The position of the aortic arch must be identified. A right-sided arch with an enhanced pulmonary pattern gives grounds to suspect OSA. With narrowing or atresia of one of the pulmonary arteries, an asymmetry of the vascular pattern is visible, sometimes in combination with lung hypoplasia.

echocardiography

2D echocardiography and Doppler echocardiography allow for precise anatomy and hemodynamic details. It makes it possible to differentiate OSA from an open aortopulmonary window, which is sometimes difficult to distinguish on angiocardiographic examination. The aortopulmonary window is usually not accompanied by MGD, and the right ventricular outflow tract is connected directly to the pulmonary trunk. With truncus valve stenosis, Doppler echocardiography allows you 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 the state of hemodynamics, and angiocardiography allows you to determine what type of OSA a given patient has, to clarify the function of the valve and the anatomy of the coronary arteries. Due to the large leakage of blood into the pulmonary bed, a large dose of contrast medium is usually required to reveal the details of the anatomy. In patients undergoing pulmonary artery narrowing surgery, a detailed examination of the coronary arteries, if necessary, including selective coronary angiography, is mandatory. This is important because epicardial adhesions during radical surgery make it difficult to directly visualize the coronary arteries and select a free site for performing 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 x-ray. In these patients, the corresponding lung is hypoplastic and should not be operated on. In patients with a break in the aortic arch, it is necessary to identify the place of the break in relation to the vessels extending from it. The state of the aortic arch and the type of OSA are usually studied in the anteroposterior and lateral projections.

A catheter inserted into the right ventricle registers an equal systemic pressure and a high oxygen content. Then it easily passes into the OSA, the arch and the 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 of their mouths. Although both ventricles pump blood into the CCA, 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, therefore, to exclude inoperability, PVR is calculated according to catheterization data.

It is difficult to assess the degree of insufficiency of the truncus valve with the introduction of a contrast agent. Predominant leakage of blood into the pulmonary bed can mask valve insufficiency, so if mild or moderate insufficiency is found on an angiocardiogram, severe valve failure may be detected at the operation, requiring prosthetics. Doppler echocardiography has an advantage over angiocardiography in this respect.

natural flow

Without treatment, the prognosis is absolutely unfavorable. Although some patients survive childhood, most infants die between 6 and 12 months of age from heart failure. Long 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. Trunkus valve insufficiency progresses over time.

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

Morphology
OSA is characterized by a single main artery originating from the base of the heart, which provides systemic, pulmonary, and coronary blood flow, and an interventricular defect. Both of these anomalies arise from septation disorders 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 pancreas, and in 16% - towards the left ventricle.

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 on 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 - the right and left pulmonary branches are significantly distant from each other and depart from the lateral surfaces of the common arterial trunk, type 4 - the pulmonary arteries depart from the descending aorta.

The classification of R. Van Praagh (1965) subdivides the defect as follows: 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 trunk separately, type A3 - only one pulmonary artery departs from the trunk ( more often right), and the other lung is supplied with blood through the arterial duct or collateral vessels, type A4 - a combination of a truncus with an interrupted aortic arch. The trunkal valve is usually deformed and the leaflets are thickened, which is accompanied by its insufficiency. Very rarely it is stenotic. Usually the truncal valve has 2 leaflets (60% of cases), less often - 4 leaflets (25%).

As a rule, the VSD is located in the anterior superior part of the septum. There are also coronary anomalies; among them more often - the discharge of both main coronary arteries in 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, which increases in volume towards the end of the neonatal period due to age-related decline in pulmonary vascular resistance. For this reason, severe pulmonary hypertension occurs early.

Truncal valve regurgitation occurs in 50% of patients and results in overpressure of the right side in addition to volume overload.

Timing of symptoms- the first weeks of life.

Symptoms
Newborns with OSA show signs of congestive heart failure due to a sharp increase in 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 dyspnea and cyanosis, poor weight gain). The severity of heart failure prevails over the severity of cyanosis with early onset of symptoms. Symptoms of HF increase in parallel with the decrease in pulmonary vascular resistance after birth.

Often determined by the pulsation of the heart, left-sided cardiac hump and systolic trembling. I heart sound has a normal sonority, a systolic ejection click is heard, II tone is strengthened and not split. A persistent systolic murmur along the left sternal border is rarely heard and is caused by pulmonary stenosis or atresia of the pulmonary artery trunk in combination with a VSD or PDA or large aortopulmonary collaterals. With regurgitation on the trunk valve, a diastolic murmur of regurgitation may additionally be heard.

Diagnostics
On the frontal chest radiograph - cardiomegaly, the vascular pattern is markedly enhanced, there is no shadow of the pulmonary artery.

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

Doppler echocardiography - using subcostal and parasternal access, signs of OSA originating from the ventricles are detected, with various types of pulmonary artery origin, 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 is best visualized from the parasternal long-axis view.

Despite topical verification of the defect by echocardiography, cardiac catheterization and angiocardiography are 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, if an anomaly of the coronary arteries is suspected.

Laboratory data - decrease in SpO2 at rest to
Fetal diagnosis
With antenatal ultrasound, the diagnosis is established more often in the period of 24-25 weeks. Trunk valve usually connects to both ventricles, but sometimes it can be shifted mainly towards one of the ventricles. In the case of atresia of one of the atrioventricular valves, the common arterial trunk departs from the single ventricle. Trunk valve regurgitation occurs in a quarter of patients, and approximately the same proportion have truncal stenosis. 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 pulmonary venous drainage. Extracardiac anomalies occur in half of the fetuses with OSA, including 22q11 microdeletions (including manifestations of DiGeorge syndrome, with hypoplasia or aplasia of the thymus).

The 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 HF 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.

Terms of surgical treatment
If the operation is performed in the period of 2-6 weeks of life, then the chances of survival are highest.

Types of surgical treatment
Pulmonary artery banding is ineffective.

In 1968, for the first time, a report was published on the successful radical correction of 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 pulmonary artery. The first successes of surgical correction were achieved in older children, which prompted other surgeons to postpone the operation. However, many children did not live up to this term and were not able to achieve the desired body weight and height. Later, in 1984, P. Ebert et al. reported excellent early and late results of radical truncus arteriosus repair in infants under 6 months of age. Then a number of surgeons achieved the same results even with the simultaneous reconstruction of the trunk valve or valve replacement if necessary, after which early surgical correction of OSA was recommended to prevent HF decompensation, severe pulmonary hypertension and cardiac cachexia in small patients. In the last 10-15 years, OSA has been operated on in the neonatal period (after the 2nd week) with a low mortality rate (5%) and a low number of complications. The operation consists of a complete correction with VSD plasty, connection of the trunk to the left ventricle, and reconstruction of the outflow tract of the pancreas.

In patients with right and left pulmonary arteries originating directly from the OSA, 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 departs from the trunk, and the second from the lower part of the aortic arch, both of them are disconnected from these sections separately, then connected together and then anastomosed with the conduit or separately to the conduit.

The results of surgical treatment
According to a number of clinics, in the 60-70s. 20th century survival after radical correction was 75%, and in the period 1995-2003. - up to 93%. Modern techniques have significantly improved the prognosis of patients. The physiological basis for improving 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 valve replacement in the presence of valve dysfunction and an individualized approach to reconstruction of the outflow tract of the pancreas also help to improve postoperative outcomes. Body weight significantly affects the outcome of the correction - the worst survival rate for children weighing less than 2500 g requiring valve replacement. Currently, in the world, perioperative mortality 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 a porcine valve, are characterized by a better result of surgical correction in infants, fewer postoperative bleeding and better survival after surgery. All homografts with a valve size less than 15 mm require replacement after 7 years. With a homograft valve size of more than 15 mm, replacement after 10 years is required only for 20% of patients.

After successful OSA reconstructive surgery, children need careful postoperative follow-up with an assessment of potential aortic (truncal) insufficiency and the function of the conduit between the pancreas and the pulmonary artery. Subsequently, they will need at least two more reconstructive operations to replace the conduit, with cardiopulmonary bypass.

Although late postoperative mortality in patients undergoing early surgical correction is minimal, it may be associated with the occurrence of problems with the state of the outflow tract of the pancreas in connection with the reconstruction (the need for replacement of the conduit, revision or dilation). In 64% of children without risk factors, freedom from reoperation is observed by the age of 7, and in 36% of children with risk factors - by 10 years.

The survival rate of children operated on in the leading cardiac surgical 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 noted in 50% of cases.

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

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

Early diagnosis, preferably even in the perinatal period, will allow you to prepare well for the provision of assistance, carefully plan it. 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, a 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 main is located most often above the partition in the place of its defect.

In the perinatal period, the child does not suffer from abnormal disorders in the structure of the heart. After birth, he acquires a cyanotic color of the skin, and other signs develop: shortness of breath, sweating.

The body experiences oxygen starvation. The right half of 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 for low blood pressure. Due to pathology, pressure is created in the pulmonary vessels, and they develop resistance, which can endanger life.

It is possible to help the child if the pathology is corrected surgically in time. If left untreated, the prognosis is poor.
Irreversible processes in the lungs make corrective surgery impossible over time. In this case, a lung and heart transplant can save.

The scheme of development of the common arterial trunk

Forms and classification

The location of the pulmonary artery, including its branches, is determined by various forms of pathology.

1. From the back of the trunk, the right and left pulmonary arteries are deployed. They come out of a common trunk and are located next to each other relative to each other.
2. The pulmonary arteries are attached to the trunk, located on the sides.
3. The trunk divides 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 arteries of the bronchi. Experts now do not attribute this pathology to the type of common arterial trunk.

Causes

The defect is formed in the child during his perinatal life. In the first three months, the detailing of the cardiovascular system takes place. This period becomes the most vulnerable to harmful influences that can contribute to the appearance of anomalies.

Harmful factors during childbearing include:

• exposure to radiation
• nicotine,
• contact with harmful chemicals,
• alcohol, drugs;
• taking medicines must be done after consultation with a specialist;
• improper formation of organs can happen if the expectant mother is ill during pregnancy:
  • flu,
  • autoimmune diseases,
  • rubella,
  • other infectious diseases;
• of chronic diseases, the danger is diabetes mellitus; a pregnant woman suffering from this disorder must be under the close supervision of an endocrinologist.

Symptoms

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

The patient has:

• sweating,
• there is a significant increase in breathing, especially during an increase in the load on the body;
• skin integuments have a different degree, depending on the depth of the problem, a bluish color,
• low tone,
• the spleen and liver may be enlarged,
• the child begins to noticeably lag behind in physical development,
• enlarged heart can cause deformation of the chest in the form of a heart hump,
• there may be a change in the shape of the fingertips, their thickening;
• pathology causes deformation of the nails in the form of "watch glasses".

Diagnostics

A newborn may already have suspected health problems if fetal examinations were performed. Early diagnosis allows you to prepare in advance and plan help for the child.

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

• Phonocardiography - the device records heart sounds on paper. Gives an accurate definition of whether there are violations, noises in them. Clarifies those tones that cannot be heard with a stethoscope.
• Electrocardiography - gives information about whether there is an increase in the chambers of the heart, whether there is an overload in their work, reveals a change in conductivity.
• Aortography - examination of the structure of the aorta. A special contrast agent is injected into it, which designates itself during an x-ray examination of the highway. 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, details about disorders in the work of the ventricles. This method is necessarily used to diagnose this defect.
• Catheterization - equipment is introduced into the region of the heart using a catheter, which transmits complete information about the structure and anomalies of internal structures.
• Echocardiography is a safe method, it provides valuable information about the structure of the main vessels and the septum between the ventricles.
• Analyzes - blood and urine tests will help to understand the general condition of the body and determine if there are other pathologies.

Treatment

The main method of helping patients with a common arterial trunk is surgery. All other procedures are aimed at maintaining a normal state before or after surgery.

Therapeutic and medicinal way

Patients who are diagnosed with the pathology of the "common trunk" should follow the recommendations of specialists in order to avoid inflammation of the membranes of the heart.

Before surgery, diuretics and glycosides are used. They relieve the condition of newborns with symptoms. This can only be a temporary measure.

Operation

The narrowing of the branches extending from the pulmonary artery improves the overall picture of the disease, and makes it possible to postpone radical intervention for some time. Therefore, there is a palliative operation that solves the problem of ligation of the pulmonary arteries.

The main method of fixing the problem is an open operation. Intervention is necessary to correct congenital anomalies by dividing the common trunk into two highways. The septal defect that almost always accompanies this type of defect is also reconstructed.

Prostheses are often used to complete the task. As the child grows older, the existing prosthesis needs to be replaced with a larger one.

Modern medicine has learned to do corrective surgery 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 in whom 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 a lung and heart transplant.

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

Disease prevention

During the bearing of a child, a woman should protect herself as much as possible from negative factors:

• not to be in a zone of unfavorable ecology,
• not be exposed to harmful chemicals,
• take medicines carefully, consult a doctor;
• stop drinking alcohol and exclude from your habits,
• do not expose yourself to ionizing radiation,
• be observed by specialists, so that if the fetus has a common arterial trunk, 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. Increased pressure in the right ventricle is not characteristic of him. It occurs due to the fact that there is a message between the arterial and venous blood, and the pressure in the ventricles is equalized.

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

Forecast

If a corrective operation is performed on time, then the prognosis is usually positive. It should be observed for a long time by a specialist and, with age, the prostheses sewn in early childhood should be replaced.

Special case: truncus arteriosus and right ventricular hypoplasia

Birth 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 the right side. The transfer of venous blood increases cyanosis. An urgent operation is required so that irreversible phenomena do not happen.

The common truncus arteriosus (CA) is a disorder in the work of the heart, characterized by a high degree of severity and congenital character. This condition is expressed in the fact that only one, not divided, blood vessel departs from the heart muscle. OSA is diagnosed in 2-3% of cases, and always in parallel with another violation that extends to the region of the interventricular septum.

The common arterial trunk is a deviation, expressed in the union of the pulmonary artery and aorta into one. The disorder occurs when the fetus develops in the mother's body. It combines arterial and venous blood, penetrating into both circles of blood circulation.

A deviation of this nature is diagnosed in newborns. The condition is very dangerous and can provoke death in case of untimely assistance, as it causes a constantly developing dysfunction of most body systems.

OSA is localized above the ventricles in two versions: above both or only above 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 trunk in a newborn in 75% is a factor in the death of a newborn even before he is one year old. In 65% of cases, death occurs before the age of six months.

The high mortality rate in OSA is due to severe. Also, a significant role is played by excessive filling of the pulmonary vessels with blood. In addition, with such a violation, the body experiences acute oxygen starvation.

Reasons for rejection

The specified heart disease is formed during the period when the fetus develops in the mother's body. The dangerous period is the first trimester, when the formation of the cardiovascular system occurs.

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

• radiation effect on the body of a pregnant woman;
• exposure to infections (viruses) that affected the body of a pregnant woman at the initial stages of fetal development;
• passing x-ray examinations by a pregnant woman;
• the intake of alcoholic beverages by a woman who is carrying a fetus;
• autoimmune diseases of a pregnant woman, which cause a conflict between the organisms of a woman and a fetus;
• influence of toxic substances;
• interaction with chemicals;
• diabetes;
• uncontrolled intake of medications.

This is not a complete list of the reasons that cause the formation of OSA: scientists have not yet come to a common opinion regarding all the factors that can provoke severe pathology.

How is pathology classified?

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

• the vessel, separating from the common trunk, is subdivided into the left and right pulmonary arteries;
• each artery is separated from the posterior wall of the common trunk;
• they move away from the side walls of the trunk;
• there are no arteries, and the lungs fill with blood through the arteries that branch off from the aorta.

The specific type of disease is determined in the course of diagnostic studies.

Distinctive features of hemodynamics

In the presence of a common arterial trunk in the fetus, pronounced disturbances occur: when the structure changes, instead of two highways emanating from each ventricle, there is only one trunk, to the area of ​​\u200b\u200bwhich blood flows from the ventricles.

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

Under normal conditions, the pressure in the right ventricle is reduced. In the case of the common arterial trunk, pressure arises in the pulmonary vessels, which in turn resist. This poses a threat to life.

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

1. A change in the volume of pulmonary blood flow upwards and an increase in pressure in the vessels of the lungs. As a result, pressure in the lungs rises and heart failure occurs. These phenomena are resistant to ongoing treatment.
2. Insignificant increase in pulmonary blood flow or the norm, not too pronounced emission of blood. Heart failure in this case is absent, cyanosis is observed during exercise.
3. Decreased pulmonary blood flow due to stenosis of the orifice 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, communication between the aorta and the pulmonary artery is stopped, then the atrial septal defect is closed with a patch. Next, create an artificial trunk of the pulmonary artery. To do this, resort to the use of a stent for the trunk.

This type of intervention is difficult, as it is performed on an open heart. In this case, a heart-lung machine is used.

If after the operation there is a positive trend, the patient must regularly take drugs that regulate blood flow.

Forecast

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

The outcome is successful if there are no pronounced changes in the pulmonary vessels during the deviation.

If the operation is successful, then the child remains alive. In the future, regular medical monitoring and the use of special drugs are required.

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 carriers of viruses in the environment of a woman.

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

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, and a large single arterial trunk is formed. It is located above the perimembranous infundibular ventricular septal defect.

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 of the 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, and HF is observed in rare cases, in contrast to 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 influence of negative factors on the body of a pregnant woman, especially in the first trimester of gestation. Among the dangerous factors that provoke the disease, there are diseases of the pregnant woman. Moreover, the unborn child develops not only congenital heart defects, but other life-threatening diseases.

Negatively affects the fetus, increasing the risk of a common arterial trunk in a newborn, chronic alcoholism of the mother. If a woman had rubella (an infectious disease) during pregnancy, this is likely to negatively affect the development of the fetus. Among the negative factors are:

• diabetes
• flu
• autoimmune diseases

The disease is provoked by physical factors, often the effect of radiation. Such a factor can cause deformities and mutations of the fetus. This includes radiation methods of research, a vivid example is x-rays. Research of this type should be carried out only as a last resort, it is 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 at an early stage of embryogenesis (5-6 weeks of fetal development) and the lack of separation of the primitive trunk into the main main vessels - the aorta and the pulmonary artery.

Due to the absence of a normal septum between the aorta and the pulmonary artery, they are widely communicated. Therefore, the common trunk departs immediately from both ventricles, it mixes arterial and venous 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, insufficiency or stenosis of the valve 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, a typical symptom of the first type of the common arterial trunk is mild cyanosis. This and the above listed signs appear when the baby is only 1-3 weeks old. In type II and III, 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 holosystolic murmur of intensity 2-4/6 is heard. At the apex, with an increase in blood flow in the pulmonary circulation, in some cases, noise is heard on the mitral valve in the middle of diastole. With insufficiency of the valve of the arterial trunk, a decreasing diastolic murmur of a high timbre is heard. 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, which are detailed above. Chest x-ray data and data obtained from the electrocardiogram are taken into account. 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 make it possible to detect cardiomegaly (it can be either slightly or strongly pronounced), the pulmonary pattern is enhanced, the right aortic arch is located in a third of patients, and 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 of the aorta and its branches by introducing a contrast agent into the lumen of the aorta. The method is necessary to identify the level of discharge of the pulmonary artery trunk, determine the state of the valvular 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 and right atrium are enlarged. 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 the common arterial valve, active drug therapy is used. It is necessary to take digoxin, diuretics, ACE inhibitors. After the course of the drug, an operation is prescribed. The benefits of intravenous infusion (infusion) of prostaglandin have not been identified.

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 endocarditis prophylaxis before surgery and dental visits, 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 the influence of chemical factors, including chemicals, drugs, narcotic substances and various alcohols
• 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