Aortic arch interruption. Double aortic arch: clinical guidelines

List of Abbreviations

SVR – systemic vascular resistance (БКК)

ВПС – congenital heart disease

APSD – aortopulmonary septal defect

DAA – double aortic arch

VSD – ventricular septal defect

ASD – atrial septal defect

ЕОК – European Society of Cardiology

CT – computed tomography

LV – left ventricle

PA – pulmonary artery

PAH – pulmonary arterial hypertension

PH – pulmonary hypertension

LA – left atrium

PVR – pulmonary vascular resistance

PCC – pulmonary circulation

CIR – circulatory insufficiency

PVR – pulmonary vascular resistance

SVR – systemic vascular resistance

IAA – interrupted aortic arch

RV – right ventricle

RA – right atrium

ART – atrial reentry tachycardia

VRA – vascular ring of the aorta

6MWT – 6-minute walk test

AF – atrial fibrillation

ECG – electrocardiography

EchoCG – echocardiography

Qp/Qs – pulmonary-to-systemic blood flow ratio

Terms and Definitions

Cardiac catheterization – an invasive procedure performed for therapeutic or diagnostic purposes in cardiovascular pathology by inserting catheters into the heart chamber or the lumen of great vessels.

Computed tomography (CT) is a non-invasive diagnostic imaging method that produces a series of cross-sectional submillimeter axial images of human body organs and structures. It is based on measuring and performing complex computer processing of X-ray attenuation differences by tissues of varying density to improve the differentiation of organs from one another, as well as of normal and pathological structures. Various contrast-enhancement techniques are used with iodine-containing radiopaque agents. To visualize the structures of the cardiovascular system, CT angiography is used—a technique involving the intravenous bolus injection of contrast agents into the bloodstream using an automated injector at a set infusion rate and time. Based on the acquired data, a three-dimensional model of the heart and blood vessels is constructed via computer post-processing with 3D reconstruction.

Magnetic resonance imaging (MRI) is a non-invasive method for obtaining tomographic medical images without ionizing radiation to study internal organs and tissues. It is based on the phenomenon of nuclear magnetic resonance and the measurement of the electromagnetic response of atomic nuclei in a strong constant magnetic field, following excitation by a specific combination of electromagnetic waves. These nuclei are hydrogen atoms present in the human body as part of water and other substances. MR angiography is a method for imaging the vascular lumen using an MRI scanner. The method allows for the assessment of both anatomical and functional features of blood flow. MR angiography relies on the difference in signal between moving protons (blood) and surrounding stationary tissues, making it possible to acquire vascular images without using any contrast agents—non-contrast angiography (e.g., phase-contrast MR angiography). In some cases, intravenous bolus contrast enhancement using paramagnetic contrast agents (gadolinium) is applied.

Level of Certainty of Evidence (LoE) – the degree of confidence that the estimated effect of a medical intervention is true [1].

Grade of Recommendation (GoR) – the degree of confidence in the certainty of the intervention's effect and that following the recommendations will bring more benefit than harm in a specific situation [1].

Fibrobronchoscopy is an examination method performed using a set of specialized equipment (a modern kit includes a probe or bronchoscope, a camera with recording and screen-display functions, manipulators, lighting, etc.) that allows for the visual assessment of the condition of the upper and lower respiratory tracts with the possibility of performing therapeutic procedures.

Echocardiography is an ultrasound imaging method aimed at investigating the morphological and functional changes of the heart and its valvular apparatus.

1. Brief information on the disease or condition

1.1 Definition of the disease or condition

Congenital anomalies of the ascending aorta and aortic arch represent a group of congenital heart and vascular defects characterized by abnormalities in the branching, location, number, or origin of the aortic arch and its branches. These include, among others, interrupted aortic arch and double aortic arch.

Interrupted aortic arch (IAA) is a congenital heart defect (CHD) characterized by the absence of continuity in the intravascular lumen or the complete absence of a segment between the ascending and descending aorta. Blood flow to the descending aorta is maintained through a patent ductus arteriosus. Synonyms: congenital absence of the aortic arch, absent aorta [1-5].

Double aortic arch implies, conversely, a duplication where an additional right or left aortic arch persists in various forms (with a patent lumen, hypoplasia, or atresia), forming a complete vascular ring around the trachea and esophagus. Synonyms: vascular ring of the aorta [1-5].

1.2 Etiology and pathogenesis of the disease or condition (group of diseases or conditions)

The etiology is not fully established, but it is known that, as in cases of other CHDs, risk factors play an important role, and the formation mechanisms are generally understood. Developmental disorders during heart formation occurring in the first trimester of pregnancy are critical for the cardiovascular system. Adverse effects in the form of damaging factors are mediated through gene or chromosomal mutations (collectively 10%) or polygenic-multifactorial inheritance (about 90%), leading to the development of CHDs, including interrupted aortic arch or vascular ring [2,3,4,5]. This pathology predominantly arises at stages X-XX of development according to Streeter's classification; however, no consensus has been established in this section, and modern concepts include well-founded notions of multifactorial inheritance, the prevailing role of the environment, unique mechanisms of anatomically distinct CHDs, genetic heterogeneity or heterogeneity of mechanisms forming a single CHD, etc. [6]. In addition, many genes responsible for the development of specific CHDs are known today [7]. In this aspect, an interrupted aortic arch, like a double aortic arch, may be part of other chromosomal abnormalities. Thus, the typical combination of many CHDs with the 22q11.2 microdeletion syndrome is no exception for interrupted aortic arch, being associated with DiGeorge syndrome (acronym CATCH 22) in more than 80% of cases [8,9,10,11]. Established risk factors for CHD formation include adverse chronic maternal conditions, such as diabetes mellitus [9]. A characteristic feature is the association of aortic arch anomalies in general, and IAA and vascular rings, with CHARGE syndrome (Coloboma, Heart defects, Atresia choanae, Retardation of growth and/or development, Genital anomalies, Ear anomalies) caused by novel 8q12.2 mutations [12].

Interrupted aortic arch is characterized by a critical condition caused by severe deviations from normal hemodynamics, in most cases shortly after birth. The combination of disorders is represented by ductus-dependent systemic circulation and a pathological left-to-right shunt (due to intracardiac shunting), causing volume overload. The volume of blood shunted to the lungs is determined almost entirely by the magnitude of pulmonary vascular resistance (PVR) and its ratio to systemic vascular resistance (SVR). Systolic pressure in the heart ventricles, ascending aorta, and pulmonary artery branches is typically equal immediately after birth, leading to severe congestion in the pulmonary circulation [13,14]. In the first days of life, provided the patent ductus arteriosus functions, hemodynamic disturbances may be relatively mild [5,6]. However, with the natural decrease in PVR, the volume of shunted blood progressively increases, leading to hypoperfusion of the respective internal organs. As a result, in most cases, against the background of developing heart failure, metabolic lactic acidosis joins in, the severity of which is exacerbated by the closure of the patent ductus arteriosus [15]. Consequently, the condition becomes critical with the development of cardiogenic shock, intracranial hemorrhage, renal failure, etc., with extremely high mortality already within the first months of life [5]. According to autopsy studies, in 75% of cases the age of the deceased does not exceed 1 month, and the median age at death ranges from 4 to 10 days [15,16]. Collaterals providing blood supply to the lower body after the closure of the patent ductus arteriosus may be present in no more than 10% of cases, but even among these patients, mortality in the first year of life is at least 90% [16]. Only isolated patients with interrupted aortic arch who survived into adolescence or older age have been described in the literature [17]. However, these may initially not have been cases of complete interrupted aortic arch, but rather coarctation of the aorta with a progressively closing lumen. Frequently, arterial hypertension typical of coarctation syndrome comes to the forefront in these cases [18].

Double aortic arch, unlike interrupted aortic arch, despite some embryological similarities in development, is not initially accompanied by hemodynamic disturbances. This anomaly is based on a disruption in the embryonic regression processes of both fourth brachiocephalic arches, as a result of which both persist subsequently [12]. This defect causes pathological changes in the form of compression of adjacent structures of varying severity [13]. It is precisely the degree of compression that determines the prognosis and timing of disease manifestation.

1.3 Epidemiology of the Disease or Condition

This group of diseases is rare even when considering the cumulative incidence. Accordingly, aortic arch interruption is an uncommon congenital heart defect (CHD) characterized by high natural mortality. Its clinical frequency varies depending on the type, not exceeding 0.5% of all cases in the structure of congenital heart disease and 1.5% of the number of critical CHDs [19,20]. Various types of interrupted aortic arch (IAA) within the pathology itself also have varying frequencies, wherein IAA distal to the left subclavian artery can account for 30–41% of aortic arch interruptions, between the subclavian and carotid arteries—55–69%, and interruption between the carotid arteries—only 4–17% [12,13].

IAA is very frequently found in combination with other CHDs. The frequency of such combinations is up to 98% [20]. Typical combinations include a patent ductus arteriosus and a ventricular septal defect (at least 90%), a bicuspid aortic valve (up to 60%), and less commonly a truncus arteriosus, a single ventricle, left ventricular outflow tract obstruction (often due to posterior displacement of the conal septum in the presence of a "malalignment" type ventricular septal defect), transposition of the great arteries, aberrant brachiocephalic branches of the aortic arch, and less frequently, an aortopulmonary window [21].

More rare are the forms of the defect that also belong to anomalies of the ascending aorta and aortic arch in the form of vascular rings such as a double aortic arch, which nevertheless is the most common vascular ring [13,15]. These are mostly single observations or limited series of patients, but according to modern data, the incidence of the defect is higher, amounting to 1:15,000 newborns [21]. DiGeorge syndrome, 22q11 chromosome deletion is observed in approximately 20% of double aortic arch (DAA) cases. Less frequent but typical concomitant CHDs are Tetralogy of Fallot, VSD, truncus arteriosus, and pulmonary atresia [22]. When present, diagnostic investigation also allows for the diagnosis of DAA. In other cases, in the absence of overt symptoms, the diagnosis of DAA can be made much later, up into adulthood.

1.4 Features of Coding the Disease or Condition

Q25.4 — Other congenital malformations of aorta (absence of aorta, double aortic arch, aortic vascular ring) – ICD-10.

1.5 Classification of the disease or condition

Vascular anomalies of the aortic arch and its branches are classified as:

I. Anomalies of the left-sided aortic arch; II. Anomalies of the right-sided aortic arch; III. Double aortic arch; IV. Persistence of the fifth aortic arch; V. Interruption of the aortic arch; VI. Other anomalies of the aortic arch (Weinberg P. classification) [13].

Interruption of the aortic arch is localized in one of the three segments of the aorta. Accordingly, this CHD is classified based on this localization.

Classification of aortic arch interruption (types A, B, and C according to Celoria G.C., Patton R.B., 1959, modified by Oppenheimer-Dekker A., 1982) [23,24].

A – interruption distal to the left subclavian artery

1. without retroesophageal or isolated subclavian arteries

2. with retroesophageal subclavian artery

3. with isolated subclavian artery

B – interruption between the subclavian and carotid arteries

1. without retroesophageal or isolated subclavian arteries

2. with retroesophageal subclavian artery

3. with isolated subclavian artery

C – interruption between the carotid arteries

1. without retroesophageal or isolated subclavian arteries

2. with retroesophageal subclavian artery

3. with isolated subclavian artery

This classification is also used by the Society of Thoracic Surgeons (STS) and is part of the International Congenital Heart Surgery Nomenclature and Database Project [25]. According to some data, this division by the level of IAA localization is also significant regarding the evaluation of other features of the defect [26]. In type A, the existing VSD can be of various localizations and types (muscular, outlet, central membranous, inlet) and the arch may be atretic or absent. In type B, the VSD is very often of the outlet type, located between the arms of the septal band with the absence of the aortomitral continuity. The aortic arch segment in the area of interruption is usually completely absent. Concomitant CHD for type A is more often a complete atrioventricular septal defect and transposition of the great arteries. For type B, these are considered to be truncus arteriosus and double outlet right ventricle.

According to the International Nomenclature, aortic vascular rings are divided into the following types [25,28,29]:

A. Complete vascular rings

• DAA

I. Dominant right aortic arch (≈ 75% of cases)

II. Dominant left aortic arch (≈ 25% of cases)

III. Balanced (without stenoses) aortic arches (≈ 5% of cases)

• Right-sided (right) aortic arch

I. Right-sided aortic arch + aberrant left subclavian artery

II. Right-sided (right) aortic arch with "mirror-image" arrangement

B. Incomplete vascular rings (slings)

• Innominate artery compression syndrome

• Pulmonary artery sling

• Aberrant right subclavian artery

In this case, the right arch in DAA gives rise to the right common carotid and right subclavian arteries, while the left arch in DAA gives rise to the left common carotid and subclavian arteries, respectively. With complete lumen obstruction, the corresponding arch (usually the left) may be represented by a ligament, which participates in the formation of the complete ring [30].

1.6 Clinical presentation of the disease or condition

In IAA, clinical manifestations such as dyspnea, respiratory distress, signs of heart failure (against the background of decreased peripheral pulsation, varying degrees of cyanosis) with progression up to the development of a shock state often occur starting from the first days of life [4,5,6]. These symptoms are characteristic of a CHD with a massive left-to-right shunt with clear signs of pulmonary hypervolemia and severe heart failure [11,12]. Typical signs include dyspnea at rest, worsening during feeding, poor weight gain, and frequent respiratory infections [5]. Regarding the risk of developing a number of severe complications, IAA at this age belongs to the group of critical CHDs having an extremely poor prognosis without necessary treatment. Thus, the risk of developing necrotizing enterocolitis is particularly high, the onset of which worsens the overall prognosis [31]. However, the prognosis in case of successful surgical treatment is radically different from the natural course of the disease. Despite the complexity, surgical correction has now been developed, and early mortality is mainly due to concomitant risk factors and low birth weight [11,14]. The latter also include, according to a number of authors, type B IAA, the need for staged treatment, and elimination of subaortic obstruction at the time of the first hospitalization [32]. Improvements in diagnostics and surgical technique, as well as the development of new surgical methods, have in recent years made it possible to significantly reduce the number of postoperative lethal complications [32,33,34,35]. Long-term results in this case are generally accompanied by high survival rates [11,32].

DAA does not cause immediate hemodynamic disorders, unlike IAA. Symptoms in DAA are caused by compression of the trachea and esophagus [12,36,37]. Their appearance is typical in the first 6 months of life and, frequently, already during the first month. Inspiratory stridor may also be present at birth, often combined with expiratory wheezing and tachypnea. In this case, stridor may worsen in various positions — for example, when the infant lies on their back rather than on their side. Often the child may assume a forced position where stridor is relieved, such as neck extension. The child's cry may be hoarse, and in the absence of overt stridor, breathing may be noisy. Another frequent symptom is the presence of a persistent barking cough. In severe obstruction, there may be episodes of apnea, severe cyanosis, and loss of consciousness. Intercostal retractions will often be evident against this background. Recurrent respiratory infections, which aggravate airway obstruction, are typical in this setting; when obstruction is less pronounced, obstructive symptoms may only be evident at such times. Signs of esophageal compression manifest as the child frequently feeding poorly, with apparent difficulties in swallowing liquids, accompanied by choking episodes and increased respiratory obstruction at these times. Solid food dysphagia is common (the most severe cases are operated on before children are old enough to be offered solid food), with the child refusing to swallow them or choking and regurgitating [12,36,37].

In summary, several points should be noted that require attention in young children with DAA:

1. Inspiratory stridor and feeding difficulties of varying severity are present, starting at different ages. With a double aortic arch, symptoms usually appear in the neonatal period or early infancy (younger than 3 months), and they are more pronounced than in a right aortic arch with a left ligamentum arteriosum. Symptoms often worsen during feeding. Affected children frequently hyperextend the neck to reduce tracheal compression.

2. A history of pneumonia is frequently identified.

Unlike in children, symptomatic vascular rings manifesting in adults are rare, and available data often emphasize dysphagia as the predominant symptom [38]. Also, vascular rings presenting in adults can mimic chronic asthma [39].

2. Diagnostics, medical indications and contraindications for diagnostic methods

The diagnosis of PDA or VDA is verified based on a summary of data from patient/parent complaints, clinical manifestations of the defect, and instrumental diagnostic methods.

The diagnosis of PDA and VDA is established based on the data of:

1. Transthoracic echocardiography;

2. Contrast-enhanced computed tomography of the heart, or magnetic resonance imaging of the heart and great vessels (with contrast);

3. Transvenous heart catheterization (angiography of the pulmonary artery and its branches).

2.1 Complaints and Anamnesis

No ESC guideline (LoE C, GoR 5)

Comments: Variability in the clinical course of PDA is possible, but the defect is never completely asymptomatic. The patient's condition depends on the type of defect, the functioning of the DA, the magnitude of PVR, and their changes with age. In the neonatal period, infancy, and early childhood, information regarding a child with suspected congenital heart disease is collected from the mother or caregivers. It is necessary to clarify whether the patients experience dyspnea, palpitations, decreased exercise tolerance, poor weight gain, or frequent bronchopulmonary infectious diseases [5,6,11-14].

ESC not specified (LoE C, GoR 4)

Comments: Mild clinical presentation can occur in VDA, and the defect may also be masked as respiratory diseases with feeding difficulties. In the presence of associated congenital heart defects (up to 25%), the diagnostic workup for the investigated congenital heart disease also allows for the detection of VDA. In the neonatal period, infancy, and early childhood, information regarding a child with suspected congenital heart disease is collected from the mother or caregivers. It is necessary to clarify whether the patients experience dyspnea, stridor, changes in the character of stridor with body position changes or neck and head tilting, choking episodes, frequent and abundant regurgitation, decreased exercise tolerance, poor weight gain, or frequent bronchopulmonary infectious diseases [5,6,11-14,36,37,40].

ESC not specified (LoE C, GoR 4)

Comments: The clinical presentation of VDA in adults is usually associated with moderate symptoms that are masked during periods of deterioration by respiratory diseases, such as pneumonia or prolonged cough. Attention should be paid to collecting data on early childhood in such patients regarding similar, unexplained symptoms in the anamnesis, such as dyspnea, stridor, changes in the character of stridor with body position changes or neck and head tilting, dysphagia episodes, decreased exercise tolerance, poor weight gain, and frequent bronchopulmonary infectious diseases [5,6,11-14,36,37,40].

2.2 Physical Examination

• In all patients with PDA, it is recommended to perform a physical examination including determination of the chest shape and palpation of the precordial area, assessment of the presence and degree of cyanosis, and palpation of peripheral vessels with assessment of the presence and character of pulsation to verify the diagnosis [4,5,6,11-14,40-44].

ESC not specified (LoE C, GoR 4)

Comments: it is impossible to establish the topographic diagnosis of PDA during a physical examination [5,40]. Physical examination aims to identify general signs that may indicate the presence of congenital heart disease: in newborns and infants, the search is aimed at identifying symptoms of heart failure or left-to-heart failure in forms of the defect accompanied by systemic hypoperfusion and significant pulmonary blood flow hypervolemia. Differentiated cyanosis may be present, which can be observed from birth, but in most cases with a VSD, this sign is not pronounced or is even absent due to a significant left-to-right shunt [40]. Given the high incidence of DiGeorge syndrome, identifying signs of this syndrome is an important aspect of diagnosis [4,41]. Attention is paid to symptoms such as hypertelorism, low-set ears, micrognathia, small "fish-like" mouth, short philtrum, bilateral cataract, slanted palmar creases, cleft lip, high arched/cleft palate, deformity or absence of auricles, and nasal malformation [42]. Palpation of great vessels in a patent DA does not reveal differences between upper and lower extremities. Constriction of the arterial duct is accompanied by weakened pulsation in the lower extremities or the left upper extremity in type B PDA [44]. In aberrant right subclavian artery arising below the interruption site, pulsation will correspondingly be weakened in the right upper extremity.

During precordial palpation, it is typical to determine a diffuse right-ventricular cardiac impulse, since pulmonary hypertension in the presence of a DA and VSD will always be present [40].

• In all patients with VDA, it is recommended to perform a physical examination with external assessment of the chest shape, palpation of the precordial area, determination of the presence and degree of cyanosis, and palpation and assessment of peripheral vessel pulsation to verify the diagnosis or identify concomitant cardiovascular pathology [5,6,27,37-40,146-148].

No ESC guideline (LoE C, GoR 5)

Comments: Physical examination often reveals nothing; however, rales of varying degrees may be detected when the vascular ring is an isolated anomaly. However, during a cardiological examination, which is usually normal in isolated cases of VDA, approximately 25% of patients will have associated cardiac anomalies possible with VDA [4,27,37,38,39,40,146-148].

• All patients with PDA are recommended to undergo heart auscultation to assess the severity of blood shunting across the VSD from left to right or through the patent ductus arteriosus into the descending aorta [5,6,11-14,45,46].

ESC not specified (LoE C, GoR 4)

Comments: Despite the general possibility of suspecting pathology upon auscultation, the defect does not have a pathognomonic and clear auscultatory picture. Characteristic auscultatory findings in patients with PDA may include the following:

– absence or mild VSD systolic murmur, decrescendo, not exceeding grade 3/6 or less [45].

– diastolic murmur over the pulmonary artery caused by pulmonary hypertension and/or enhanced second heart sound over the pulmonary artery

– continuous systolic-diastolic murmur of collateral blood flow between the ascending and descending aorta [46].

• All patients with VDA are recommended to undergo heart auscultation to identify concomitant cardiovascular pathology [5,6,40,41,45,47-49].

ESC not specified (LoE C, GoR 4)

Comments: Despite the absence of intracardiac murmurs, auscultation data in VDA allow suspecting the presence of concomitant cardiac pathology (occurring in up to 25%), but the defect does not have a pathognomonic and clear auscultatory picture. Characteristic auscultatory findings in patients with PDA may include the following:

– conducted rales of various characters referred to the neck, cough [40,41,45,47-49].

2.3 Laboratory Diagnostics

No ESC guideline (LoE C, GoR 5)

No ESC guideline (LoE C, GoR 5)

ESC IC (LoE C, GoR 5)

Comments: changes in the blood count and basic biochemical parameters are frequent in patients with congenital heart disease, both upon the development of pulmonary hypertension and prior to the onset of this complication. Furthermore, in the presence of various comorbid conditions, laboratory abnormalities require interpretation and, if necessary, appropriate treatment. When planning surgical treatment, evaluation is essential to assess for neutropenia, anemia, thrombocytopenia, etc. [35,51-54].

ESC IC (LoE C, GoR 5)

Comments: Hemostatic disorders must be ruled out in patients with IAA or DAA, as they carry an increased risk of bleeding and thrombosis during surgical interventions [51-54].

ESC IC (LoE C, GoR 5)

Comments: patients with IAA may exhibit changes in biochemical blood parameters, in some cases associated with a severe general condition [59]. In severe obstructive syndrome, similar shifts can also be observed in aortic arch vascular rings, including DAA [35,51-54].

ESC IC (LoE C, GoR 4)

Comments: Detection of concomitant genetic anomalies aims to identify them, as they are frequently associated with IAA or DAA [10,12,13,55]. The determination of respective changes in biochemical parameters is required for the diagnosis and management of potential complications [55,150-151].

ESC IC (LoE C, GoR 4)

Comments: Identification of concomitant immune disorders in DiGeorge syndrome, including native T-cell counts and mitogenic response (T-cell proliferative response to antigen exposure), is necessary to detect corresponding changes in immunological parameters and to manage potential complications [10,12,13,55,149-151].

ESC IIa B-NR (LoE C, GoR 4)

Comments: Testing is not limited to DiGeorge syndrome or CATCH22 anomalies. When indicated by phenotypic features, a diagnostic search is performed for trisomy 21 (Down syndrome) and trisomy 18 (Edwards syndrome) [55-57,151].

2.4 Instrumental Diagnostics

• All patients with IAA and DAA are recommended to undergo electrocardiography (ECG) to determine left and right heart chamber overload and to assess cardiac rhythm and conduction [5,6,12,14,40,58-60,152].

ESC not specified (LoE C, GoR 4)

Comments: The ECG findings in DAA are generally within normal limits, except in cases of associated congenital heart disease; however, in all cases, the study allows for the suspicion of concomitant pathology if present and supported by corresponding ECG manifestations. In IAA, ECG typically reveals signs of right ventricular rather than left ventricular hypertrophy; also, in typical cases, the electrical axis of the heart (EAH) is normal or deviated to the right with right bundle branch block conduction abnormalities [5,6,12,14,40]. When pulmonary hypertension develops, P pulmonale, rightward deviation of the electrical axis of the heart, right ventricular hypertrophy, right ventricular volume/pressure overload ("strain" pattern), right bundle branch block, and prolonged QT segment are also observed [58]. The latter two signs indicate explicit disease severity, whereas hypertrophy and overload signs possess sufficient sensitivity and specificity for screening studies [59,60,152].

• All patients with IAA and DAA are recommended to undergo chest X-ray to determine heart configuration and pulmonary circulation status, as well as to rule out potential concomitant pathology [5,6,12,14,40,61-63].

No ESC guideline (LoE C, GoR 5)

Comments: X-ray findings in IAA are similar to those in children under one year of age with hemodynamically significant congenital heart disease and a massive left-to-right shunt [5,6,12,14,40,61]. The vascular shadow of the great vessels is often narrowed, especially in the absence of the thymus in concomitant Di George syndrome. The pulmonary vascular pattern is enhanced due to both arterial and venous components. Enlargement of the cardiac silhouette due to both ventricles is characteristic; a particularly sharp increase is observed following PDA closure as a result of acute hypervolemia and volume overload of the left ventricle. The aortic contour lacks the "beak" of the ascending segment due to its reduction and more vertical orientation. The trachea lacks the characteristic deviation caused by the aortic arch and, accordingly, has a midline position. In the absence of a ventricular septal defect and PDA, the radiographic picture resembles coarctation of the aorta; rib notching may appear at an older age [40,62,63].

In DAA, the localization of the aortic arch is poorly defined on X-ray imaging. In cases of pronounced tracheal compression, the trachea may be visualized in the anteroposterior or lateral projections. Signs of aspiration pneumonia may be present. When computed tomography is not feasible, barium esophagography is informative for establishing the diagnosis; in DAA, the shadow of the contrasted esophagus will exhibit two indentations on both sides, typically more pronounced on the right in the anteroposterior projection and more prominent posteriorly in the lateral projection [11,12,40].

• All patients with suspected IAA or DAA are recommended to undergo transthoracic echocardiography (TTE) with color Doppler flow mapping, which is the primary diagnostic tool for establishing the diagnosis of IAA, determining its type, right and left ventricular function, heart valve function, and the volume and direction of blood shunting [5,6,12,14,40,61,64,65].

ESC IC (LoE A, GoR 2)

Comments: Echocardiography (EchoCG) is an essential diagnostic method for establishing the diagnosis of IAA and assessing anatomy: it provides information on the location and size of the VSD, presence of subaortic obstruction, severity of volume overload and ventricular hypertrophy, aortic arch anatomy, degree of pulmonary hypertension, interrelations and sizes of the great vessels, and marked disproportion between the dilated pulmonary artery and the aorta. The accuracy of this method for visualizing IAA is quite high, making it possible to differentiate the pathology from coarctation of the aorta with tubular hypoplasia of the arch [40,64]. The method also makes it possible to determine the type of aortic arch interruption based on a number of features (blood flow direction in the great vessels, visualization of the vascular contour, etc.). Assessment of the coronary bed by EchoCG is challenging; nevertheless, potential coronary artery anomalies are subject to echocardiographic evaluation [64,65].

Echocardiography (TTE) is also a widely used diagnostic method for establishing the diagnosis of DAA. The method provides information on the type of DAA, the location of stenotic segments, and the interrelation and size of the right and left arches. The diagnostic accuracy of echocardiography for visualizing DAA is relatively high; however, given the high frequency of various deviations from "standard" anatomy, additional examinations using other imaging modalities are often required [40,64].

• Prenatal fetal echocardiography (FEchCG) is recommended for examining pregnant women, both for the primary diagnosis of PDA and when findings require differential diagnosis in suspected congenital heart disease (CHD) in the fetus [64,66,67,68].

ESC IC (CBR A, LCE 2)

Comments: Performing FEchCG in PDA has high informativity with an accurate diagnosis in approximately 80% of cases [66,67,68]. Currently, the resolution of the method is improving; intrauterine scans in the four-chamber view, three-vessel and trachea view are considered informative [68].

• Prenatal fetal echocardiography (FEchCG) in suspected double aortic arch (DAA) in the fetus is recommended both for the primary diagnosis of DAA and when findings require differential diagnosis in suspected fetal CHD [68,69,70-75].

ESC IC (CBR A, LCE 2)

Comments: Performing FEchCG for DAA has high informativity, with diagnostic accuracy ranging from 60% to 100% [71-75]. As with most aortic vascular rings, the most informative ultrasound planes are considered to be the four-chamber view and the three-vessel and trachea (3VT) view [68,69,70,71]. Not only and not so much the fact of establishing an accurate diagnosis is important, but also the possibility of referring pregnant women with suspected this pathology to maternity hospitals capable of managing newborns with possible respiratory distress syndrome as a complication of a complete vascular ring [71].

• Transesophageal echocardiography (TEE) is recommended intraoperatively during CHD correction when necessary in patients with PDA and DAA [76,77,78].

No ESC guideline (LoE C, GoR 5)

Comments: The method is described as an intraoperative study to monitor the efficacy of the performed intervention in a number of congenital heart defects (ВПС), including various anomalies of the aortic arch branches [70]. Currently, echocardiographic technologies are being introduced to improve diagnosis using three-dimensional imaging, tissue Doppler echocardiography, and contrast echocardiography.

ESC IIaC (LoE C, GoR 5)

Comments: CT plays an increasingly important role in the diagnosis of PDA, DAA, and other vascular rings in both pediatric and adult patients: it provides high spatial resolution and rapid data acquisition, and allows the detection of concomitant parenchymal lung diseases. Ventricular size and function can be assessed at a lower time cost compared to MRI. CT is currently more widely available than MRI and therefore plays a special role in emergency situations. Cardiac CT is an alternative to MRI in patients with implanted pacemakers or defibrillators. Recent improvements, such as ECG gating and new rotational techniques, reduce radiation dose and make the examination less dependent on heart rate, which may make CT a more attractive imaging modality in the coming years [5,6,12,14,40,79].

No ESC guideline (LoE C, GoR 5)

Comments: Performing MRI in newborns presents technical difficulties and limited availability, and therefore is not routinely performed. At the same time, cardiac MRI improves visualization capabilities, particularly for assessing ventricular volume overload and quantifying blood shunting in the presence of septal defects. The method allows for three-dimensional anatomical reconstructions with high spatial and temporal resolution, volumetric measurements, assessment of vessels and myocardial fibrosis. MRI can be used in the following clinical situations:

- as an alternative to echocardiography if required by the clinical task, since MRI is more informative compared to echocardiography in the quantitative assessment of right ventricular (RV) volumes and ejection fraction, RV outflow tract obstruction, pulmonary regurgitation, evaluation of the pulmonary arteries (stenosis, aneurysms) and aorta (aneurysm, dissection, coarctation); systemic and pulmonary veins (anomalous drainage, obstructions, etc.), collaterals and arteriovenous malformations (superior to CT capabilities), in coronary artery disease (inferior to CT), evaluation of intra- and extracardiac masses (inferior to CT), quantitative assessment of myocardial mass (left and right ventricles), detection and quantification of myocardial fibrosis/scar (late gadolinium enhancement reveals improvement); tissue characterization (fibrosis, fat, etc.) [72].

- MRI is generally indicated when standard echocardiographic data are inconclusive.

- MRI implements the ability to non-invasively measure hemodynamic parameters based on velocity-encoded phase mapping to determine the degree of regurgitation and the Qp/Qs ratio [81].

ESC IC-EO (CBR C, LCE 5)

Comments: Cardiac catheterization is not routinely used today for the diagnosis of isolated forms of PDA and DAA [11,12]. The technique is reserved for cases with complex associated CHD.

Cardiac and vascular catheterization in PDA is absolutely indicated upon reaching the age of 6 months and older without surgery [7].

ESC IC-EO (CBR C, LCE 4)

Comments: Flexible bronchoscopy in PDA and DAA is also recommended if therapeutic and diagnostic procedures using this method are planned [88,90].

Flexible bronchoscopy is not routinely used for the diagnosis of isolated forms of DAA [88]. The technique is reserved for cases where it is necessary to assess the degree, level, and extent of obstruction, as well as the prognosis for restoring the patency of the tracheobronchial tree and expansion of deformed areas. The procedure is also indicated if therapeutic measures aimed at sanitizing the tracheobronchial tree and other therapeutic and diagnostic actions are planned [89,90]. In PDA, the method can be used postoperatively if there is a suspicion of bronchial obstruction caused by a change in the position of the aorta after CHD correction.

2.5 Other Procedures

• Before discharge from the hospital, all patients are recommended to undergo electrocardiography for follow-up after surgical intervention [11,12,152-154].

No ESC guideline (LoE C, GoR 5)

• Before discharge from the hospital, all patients are recommended to undergo echocardiography for follow-up after surgical intervention [11,12,152].

No ESC guideline (LoE C, GoR 5)

3. Treatment, including drug and non-drug therapies, diet therapy, and pain management

3.1 Conservative Treatment

Supportive therapy

The management strategy for PDA is determined by the degree of hemodynamically significant disorders. Surgical treatment is indicated for all patients with PDA. For children amenable to therapy, surgical intervention may be deferred in cases of high surgical risk or until the patient's condition is relatively stabilized.

• In neonates with PDA showing signs of lesser circulation hypervolemia and heart failure symptoms, appropriate medical therapy is recommended while addressing the feasibility of surgical treatment [7,11,37,47,91,92].

ESC I (CBR C, LCE 4)

Comments: In neonatal patients at high risk of surgical intervention due to associated CHD and/or other aggravating factors and with manifestations of heart failure, it is advisable to resort to conservative therapy using diuretics, beta-blockers, and angiotensin-converting enzyme inhibitors. Treatment should serve as a "bridge" to surgical correction of CHD.

• Loop diuretics are recommended for patients with PDA and heart failure to relieve edematous syndrome [12,,158-161,166-167].

ESC none (CBR C, LCE 5)

Comments: Randomized controlled trials on the use of diuretics for IAA, as for many other CHD, are lacking, but clinical data demonstrate a distinct improvement in symptoms when "loop" diuretics are used in patients with heart failure. When prescribing diuretics, forced diuresis should be avoided and systemic blood pressure, electrolyte levels, blood creatinine, urea, and hematocrit should be carefully monitored to prevent hemoconcentration in response to a decrease in intravascular blood volume, hypokalemia, and prerenal failure. In cases of severe systemic hypotension and anasarca, intravenous infusion of furosemide** is indicated under the control of systemic blood pressure, central venous pressure, and hourly diuresis. If indicated, inotropic support under hemodynamic monitoring in an intensive care unit should be considered. It is advisable to combine "loop" diuretics (#furosemide** (solid oral dosage form is off-label in children under 3 years of age), #torasemide** (solid oral dosage form is off-label in children under 18 years of age)) with aldosterone antagonists (#spironolactone** (off-label in children under 3 years of age), #eplerenone** (off-label in children under 18 years of age)) [166-167].

ESC IB (LoE C, GoR 5)

Comments: #Digoxin** (solid oral dosage form is off-label in children under 3 years of age) allows controlling the heart rate in patients with supraventricular arrhythmias associated with ventricular dysfunction. The drug increases RV contractility in patients with pulmonary hypertension, pulmonary pathology, and biventricular chronic heart failure [162-165].

No ESC guideline (LoE C, GoR 5)

Comments: isolated administration of #digoxin** in this situation is ineffective, and the clinical effect of monotherapy is significantly lower than that of combination treatment [121,162-165].

No ESC guideline (LoE C, GoR 5)

Comments: To increase cardiac output, cardiotonic agents other than cardiac glycosides are used (#dobutamine**, #dopamine**, #levosimendan** (off-label in children under 18 years of age)) and, if necessary, norepinephrine** to maintain blood pressure [129,158-161].

3.2 Surgical Treatment

The presence of aortic arch vascular pathology in itself is an indication for surgical treatment in all cases, provided the patient is operable.

• In all patients with IAA and VAA, the only recommended way to eliminate the pathology is surgical treatment [5,6,11,12,38,39,41,46,92, 93].

ESC IC (LoE C, GoR 4)

Comments: considering the extremely poor prognosis without surgical treatment in all cases of IAA and in the presence of early clinical manifestations in VAA, timely surgical treatment should be performed in newborns for IAA and in infants for VAA.

In VAA, elective correction in newborns is possible. Radical treatment in groups of patients older than one year and even in adolescence, if the diagnosis is established for the first time, has also been reported to be possible and necessary in VAA [46]. However, while in the former case these are selective and small groups, in the older age group these are rare, isolated patient observations [38,39,41].

• Surgical treatment for newborns with IAA, given that the CHD is critical, is recommended to be performed urgently, unless the patient is deemed inoperable [11,84-86].

ESC IC (LoE C, GoR 5)

Comments: In general, if the patient is stable, the surgery is performed soon, but there is no extreme emergency.

In critical cases with signs of PDA closure, stabilization is required, an essential component of which is immediate intravenous infusion of prostaglandin group drugs at a rate of 0.003-0.02 mcg/kg/min under the control of capillary blood oxygen saturation, appearance of pulse in the lower extremities, and relief of lactic acidosis caused by hypoperfusion of the lower half of the body [85,86,127-129]. The infant typically also requires mechanical ventilation, while avoiding ventilation with a high oxygen concentration. Measures to increase pulmonary vascular resistance (e.g., increasing pCO₂ concentration) are also applied. To stabilize the condition, surgery can be delayed for 6-12 hours. The presence of severe chromosomal anomalies with an unfavorable prognosis for life may serve as a criterion of inoperability [11,127-129].

• In all patients with VAA presenting with symptoms of severe airway obstruction caused by this CHD, surgical correction of the defect is recommended [11,87,88,89,90].

ESC IC (LoE C, GoR 4)

Comments: Complications, in the presence of overt symptoms due to compression of the upper airway and/or esophagus by the vascular ring, which develop without surgical treatment, include hypoxic spells, apnea attacks, and later, tracheal and bronchial damage [87]. Therefore, long-term postponement of surgical treatment is not recommended.

• In all patients with VAA presenting with symptoms of tracheal or esophageal compression in the early postnatal period, early surgical correction of the defect (in the first months of life) is recommended [11,87,88,89,90].

ESC IC (LoE C, GoR 4)

• When managing patients with VAA who have severe forms of the defect, it is recommended to adhere to a multidisciplinary approach involving related specialists (thoracic surgeons, endoscopic physicians, etc.) when necessary [11,87,91,154-157].

ESC IC (LoE C, GoR 5)

Comments: Some forms of aortic arch vascular anomalies present particular challenges for correction, such as the combination of a "ring-sling" complex with associated CHD, where surgical treatment involves not only the elimination of the vascular anomaly but also interventions on the trachea [91,154-157].

• Single-stage surgical treatment is recommended for patients with IAA (including when combined with other CHD), if their correction is feasible [6,11,32-36,92-101].

ESC IC (LoE C, GoR 5)

Comments: the operation is performed under cardiopulmonary bypass with separate cannulation of the ascending and descending aorta, through the PDA, which usually does not require deep hypothermia. In these cases, the aortic arch reconstruction stage can be performed under selective cerebral perfusion.

When using a single arterial cannula technique followed by circulatory arrest, the level of hypothermia applied is deep (in some cases down to 18 ℃).

After aortotomy, the maximum possible removal of ductal tissues is necessary [11,92]. Depending on the anatomy and the surgeon's preference, aortic arch reconstruction can be performed using native aortic tissues with an end-to-side anastomosis or using other techniques [94].

If there is a significant distance in the aortic arch interruption area, a high risk of left main bronchus compression in case of excessive tension of the anastomosis on the aortic arch, and to achieve an aortic arch shape close to native ("Romanian"), the use of homograft or valveless homograft tissues, or pulmonary artery autologous tissues is possible [32-36,95-101].

• During radical correction of IAA using additional materials for aortic arch reconstruction and to eliminate associated septal defects, the intervention is recommended to be performed using native tissues or any certified material (medical device with a registration certificate: patch, conduit, homograft) [4,7,32-35,101].

ESC I C (LoE C, GoR 5)

Comments: correction of IAA using additional materials involves the use of homograft or native pulmonary artery tissues for aortic arch reconstruction and, in the presence of an associated ventricular septal defect, a synthetic or biological material patch fixed with continuous or interrupted sutures [4,7,101].

• Staged surgical treatment is recommended for patients with IAA, including when combined with other CHD, if their simultaneous correction is not feasible [7,84,101,102-106].

ESC IC (LoE C, GoR 5)

Comments: in cases where radical correction under cardiopulmonary bypass is associated with excessive risk (low body weight, prematurity, complex anatomy of associated congenital heart defects, etc.), staged palliative treatment is considered [101-106]. 

• Hybrid surgical treatment is recommended selectively for patients with interrupted aortic arch combined with comorbid pathology when surgery under cardiopulmonary bypass must be avoided [107,108].

ESC IC (LoE C, GoR 4)

Comments: the hybrid method is a variant of staged surgical treatment in cases where radical correction under cardiopulmonary bypass carries an excessive risk (low body weight, prematurity, complex anatomy of associated congenital heart defects, etc.), and is intended as a "bridge" to radical correction, which is usually performed 2 to 8 months after the first stage [107,108]. 

• In patients after prior radical surgery for interrupted aortic arch who subsequently develop recurrent obstruction on the reconstructed neo-aortic arch or left ventricular outflow tract with moderate or more pronounced stenosis, repeat intervention is recommended if there are complaints of decreased physical activity or cardiac arrhythmias [6,11,12,109-113].

ESC IIa B-NR (LoE C, GoR 4)

Comments: Residual or newly occurring abnormalities of the neo-aortic arch and/or left ventricular outflow tract following IAA correction are a widely recognized problem. Reoperations for this defect can be performed using any technique from primary correction, including end-to-side anastomosis, conduit implantation, arch enlargement with a patch or pulmonary autologous tissue. Both new obstruction and progression of pre-existing, previously mild left ventricular outflow tract obstruction may be observed [6,11,12,109-113].  

• In adult patients after prior radical surgery for interrupted aortic arch without symptoms and with severe stenosis of the neo-arch, repeat intervention is recommended if a decrease in left ventricular ejection fraction or left ventricular dilatation is detected [11,12,113-115].

ESC IIb B-NR (LoE C, GoR 5)

Comments: The high predisposition to repeat interventions after radical IAA correction is due to the baseline anatomy of the defect and the lack of a universal "ideal" technique, requiring the use of conduits in a number of cases. Timely reoperation to relieve progressive obstruction of the aortic arch or left ventricular outflow tract helps prevent myocardial pathological changes, cardiomegaly, and cardiac arrhythmias. Repeat interventions include open, endovascular, and hybrid surgeries [113-115].  

3.3 Endovascular interventions

• In patients after prior radical surgery for interrupted aortic arch using a conduit or another technique in the presence of hemodynamically significant obstruction, endovascular balloon dilation is recommended as a palliative measure to relieve obstruction or as a trial procedure to assess the compliance of the obstructed area prior to stent implantation into the obstruction zone [116-119].

ESC IIb C (LoE C, GoR 5)

Comments: Percutaneous balloon dilation of the restenosed neo-aortic arch area is currently considered a procedure with a relatively short-term and not always achievable positive effect [118]. This is explained by the nature of the obstruction, especially when a conduit was used during the primary operation in the long term, including conduit overgrowth, intimal proliferation, kinking and external compression, calcification, and valve degeneration [118, 119].  

• Percutaneous stent implantation in patients after radical IAA correction is recommended for adult patients with hemodynamically significant neo-aortic arch obstruction and suitable anatomy [116-119].

ESC I B (LE R, LoE 5)

Comments: stent implantation is performed when it is anticipated that (a) the procedure will significantly reduce the obstruction (or prolong conduit function if the latter was used) until a subsequent intervention is required, (b) stent implantation will not cause deformation of the pulmonary artery branch bifurcation and will not compromise the tracheobronchial tree, (c) will not compromise the aortic arch branches.

Percutaneous stent implantation into the neo-aorta represents a viable alternative to open surgical treatment in adult patients with recurrent aortic arch obstruction. Despite its minimally invasive nature, by no means all cases are anatomically suitable for this procedure [118,119].

3.4 Other treatment

No.

4. Medical Rehabilitation and Sanatorium-Resort Treatment

No ESC recommendation, LoE C, GoR 5

Comments: The following conditions may occur after radical correction of the defect:

- Postpericardiotomy syndrome and cardiac tamponade may occur several weeks after surgical correction of IAA. Consequently, symptoms such as fever, fatigue, vomiting, chest pain, or abdominal pain may appear. An echocardiogram must be performed immediately to rule out this complication. Monitoring and (if necessary) treatment in accordance with established guidelines.

- Residual interventricular shunt during IAA correction with VSD may occur in up to 5% of cases after defect correction. Reoperation is indicated for hemodynamically significant blood shunting.

- Neo-aortic stenoses may occur after defect correction. In such cases, reoperation is indicated for a hemodynamically significant degree of obstruction. Catheter intervention is possible if technically feasible and the stenosis morphology is appropriate.

- Cardiac rhythm and conduction disorders (atrioventricular blocks, supraventricular tachyarrhythmias, and sudden cardiac death) may occur both immediately after surgical correction of IAA and at later stages.

- Residual PAH may persist in up to 5% of cases after defect correction (especially after late surgical correction of IAA). Monitoring and (if necessary) prescription of PAH-specific therapy are carried out based on established PH guidelines.

- Neurological disorders—encephalopathy, seizure syndrome, etc.—occur in up to 2% of cases and require ongoing follow-up by a neurologist at the place of residence [11,12,109,113-119,130-141].

No ESC recommendation, LoE C, GoR 5

Comments: One year after radical correction, patients operated on for DAA may be cleared for all competitive sports in the absence of: 1) signs of tracheal and esophageal compression, 2) significant aortic arch obstruction, 3) arrhythmias, 4) signs of ventricular myocardial dysfunction, 5) signs of PH.

5. Prevention and Dispensary Observation

The prognosis after surgical correction of IAA and DAA is (in most cases) favorable provided the congenital heart defect is corrected in a timely manner. Life expectancy and physical performance may be limited if iatrogenic residual complications are present [11,12,109,113-119,130-141].

ESC/RSC IIa, LoE C, GoR 5

Comments: Frequency of dispensary follow-up with a pediatric cardiologist and adult cardiologist at 3 (if indicated), 6, and 12 months after surgery. Regular monitoring is advisable during the first 2 years, and then, depending on the intervention results, every 12–60 months until 18 years of age; the patient then transitions to the adult outpatient clinic, where follow-up continues at the same frequency, if indicated, by a cardiologist, general practitioner, or internist. Dispensary follow-up includes ECG, echocardiography, 24-hour Holter ECG monitoring, and pulse oximetry if necessary.

Patients with ventricular dysfunction, residual atrial shunt, stenosis and occlusion of the venae cavae and pulmonary veins, venous thrombosis, cardiac rhythm and conduction disorders, PAH, and neurological disorders must be followed up annually at specialized centers.

When determining the frequency of follow-up, one should be guided by the presence of heart failure symptoms, hemodynamic status, cardiac arrhythmias, hypoxemia, etc. Depending on these factors, all patients with CHD can be divided into four groups (A, B, C, D):

Group A

- heart failure functional class I;

- absence of anatomical hemodynamic disorders;

- absence of cardiac arrhythmias;

- normal liver, kidney, and lung function.

Group B

- heart failure functional class II;

- minimal stenosis and/or valve regurgitation (grade I),

- mild dilation of the aorta or ventricle(s);

- LVEF at least 50%, right ventricular EF at least 40%;

- hemodynamically insignificant intracardiac shunts (Qp/Qs<1.5);

- absence of hypoxemia;

- cardiac arrhythmias not requiring treatment;

- absence of signs of pulmonary hypertension;

- normal kidney and liver function.

Group C

- heart failure functional class III;

- moderate or significant stenosis and/or valve regurgitation (degrees II–III), arterial or venous stenosis, moderate dilation of the aorta or ventricle(s);

- LVEF 40–49%, RV EF 35–39%;

- hemodynamically significant intracardiac shunts (Qp/Qs ≥1.5);

- moderately severe hypoxemia (SatpO2 ≥ 85%);

- cardiac arrhythmias controlled by therapy;

- pulmonary hypertension (pulmonary hypertension FC I–II);

- internal organ dysfunction controlled by therapy.

Group D

- heart failure FC IV;

- significant aortic dilation;

- severe hypoxemia (SatpO2 < 85%);

- cardiac arrhythmias refractory to therapy;

- pulmonary hypertension (pulmonary hypertension FC III–IV);

- internal organ dysfunction refractory to ongoing therapy.

Depending on whether a patient with a corrected or uncorrected defect belongs to a particular functional class, different follow-up frequencies and scopes of required instrumental examinations are recommended:

ESC/RCS IC, LoE C, GoR

ESC IIA, LoE C, GoR 5

Comments: The test is necessary to determine the optimal physical activity volume, objectively assess cardiac functional capacity, and detect potential arrhythmias. The test is performed using a cycle ergometer test, treadmill test, or possibly a 6-minute walk test with dyspnea assessment using the 10-point Borg scale and pulse oximetry.

ESC/RCS IC, LoE C, GoR 5

ESC/RCS IC, LoE C, GoR 5

ESC/RCS IIaC, LoE C, GoR 5

ESC/RCS IB, LoE C, GoR 4

Comments: An ECG should be performed to assess cardiac rhythm and heart rate. Patients who have undergone radical correction may exhibit sinus node dysfunction with daytime heart rate dropping below 40 bpm and pauses exceeding 3 seconds, as well as atrial re-entrant tachycardia (ART)/AF with rapid conduction to the ventricles and potential development of ventricular tachycardia, which is a risk factor for sudden cardiac death. Detection of atrial flutter, atrial fibrillation, or paroxysms of ventricular tachycardia indirectly indicates pronounced intracardiac hemodynamic disturbances.

ESC/RCS IIa C, LoE C, GoR 5

Comments: Holter ECG monitoring is necessary to rule out cardiac rhythm and conduction disorders that may be recorded after radical correction of PDA. The most severe disorders are those characterized by a daytime heart rate drop below 40 bpm and pauses exceeding 3 seconds, as well as ART/AF with rapid conduction to the ventricles and potential development of ventricular tachycardia, which can cause sudden cardiac death. For patients with brief, hemodynamically stable episodes of ventricular tachycardia, specific treatment is generally not administered, or drugs suppressing ectopic focus activity (beta-blockers) are prescribed. Patients with syncopal or presyncopal states receive more "aggressive" treatment. This includes antiarrhythmic therapy and implantation of an implantable cardioverter-defibrillator, which is the only method for preventing sudden cardiac death in this category of patients.

Conservative treatment is largely ineffective for patients with ART and AF after radical correction of PDA. In such cases, all patients must undergo intracardiac electrophysiological study and radiofrequency ablation.

If the daytime heart rate drops below 40 bpm with pauses exceeding 3 seconds, pacemaker implantation is required [5,6,12,14,40,58-60,109,113-119,130-141].

Comment: The obtained data allow for timely adjustment of conservative therapy or resolution of the question regarding the need for reoperation when indicated [109,113-119,130-141].

ESC/RCS none, LoE C, GoR 5

ESC/RCS IIa C, LoE C, GoR 5

ESC/RCS none, LoE C, GoR 5

Comments: For any type of congenital heart disease treated with synthetic materials or prostheses, bacterial endocarditis prophylaxis is indicated for 6 months after surgery or lifelong if residual shunts or valve regurgitation persist. Endocarditis prophylaxis is performed during dental procedures, accompanied by damage to the oral mucosa (tooth extraction, manipulation in the periapical zone of the tooth, etc.) [134].

ESC/RCS IIaC, LOR C, LOE 5

6. Organization of Medical Care

Stages of medical care:

1. Primary health care;

2. Specialized outpatient care;

3. Specialized inpatient medical care and/or high-tech inpatient care;

4. Postoperative rehabilitation stage, dynamic follow-up;

5. Type of medical care: specialized medical care, primary health care, emergency medical care;

6. Conditions of medical care: inpatient, outpatient, outside a medical organization;

7. Form of medical care: elective, emergency.

Indications for elective hospitalization:

1. Presence of congenital heart disease (IAA);

2. Presence of symptoms of circulatory failure;

3. Presence of pulmonary hypertension;

4. Presence of supraventricular rhythm and cardiac conduction disorders;

5. Diagnostic ambiguity and the need for special research methods (use of diagnostic procedures that are impossible or impractical in an outpatient setting) to clarify the cause and severity of IAA or corrected PDA;

6. Elective surgical intervention for IAA or repeat elective surgery in patients with PDA.

Indications for emergency hospitalization:

1. Prenatally or postnatally diagnosed interrupted aortic arch;

2. Life-threatening complications after repair of PDA or IAA;

3. Paroxysm of supraventricular or ventricular arrhythmias, or severe cardiac conduction disturbances with syncopal and presyncopal states;

4. Decompensation of chronic heart failure.

Indications for patient discharge from the hospital:

1. Completed surgery for surgical correction of PDA or IAA with a completed period of postoperative observation, management of perioperative complications;

2. Titulrated pharmacotherapy for CHF, antiarrhythmic and PAH-specific therapy if indicated;

3. Compensation of heart failure symptoms.

7. Additional Information

• Patients with PDA and the development of postoperative complications are recommended to avoid excessive physical activity until the resolved complications are eliminated [109,113-119,130-141].

ESC IB (LOR C, LOE 5)

ESC none (LOR C, LOE 5)

• In patients with a history of infective endocarditis, as well as with a residual shunt in VSD, infective endocarditis prophylaxis is recommended [130-141].

ESC IA (LOR C, LOE 5)

Pregnancy and childbirth

Pregnancy and childbirth are usually well tolerated [130-141]:

- against the background of corrected IAA and PDA;

- in patients with preserved LV function;

- with I-II functional classes according to NYHA;

- in the absence of significant pulmonary hypertension and significant right ventricular outflow tract obstruction;

Criteria for Evaluating the Quality of Medical Care

References

Appendix A1. Working Group Composition

1. Avramenko A.A. (Samara)

2. Alekyan B.G., Academician of the RAS, "Russian Scientific Society of Endovascular Diagnostics and Treatment Specialists", (Moscow)

3. Belov VA (Perm)

4. Bogdanov V.N. (Chelyabinsk)

5. Bokeria L.A., Academician of the RAS, "Association of Cardiovascular Surgeons of Russia", (Moscow)

6. Boriskov M.V., DSc in Medical Sciences, (Krasnodar)

7. Borisova N.A., "Russian Scientific Society of Endovascular Diagnostics and Treatment Specialists", (Saint Petersburg)

8. Brodsky A.G., PhD in Medical Sciences, (Surgut)

9. Gavrilov R.Yu., "Association of Cardiovascular Surgeons of Russia", (Volgograd)

10. Grigoryan A.M., PhD in Medical Sciences, "Russian Scientific Society of Endovascular Diagnostics and Treatment Specialists", (Moscow)

11. Gladyshev I.V., (Chelyabinsk)

12. Gorbatikov K.V., DSc in Medical Sciences, (Tyumen)

13. Gorbatykh Yu.N., DSc in Medical Sciences, (Novosibirsk)

14. Gulyaev YV (Moscow)

15. Evtushenko A.V., Russian Society of Cardiology, (Kemerovo)

16. Zelenikin M.M., DSc in Medical Sciences, "Association of Cardiovascular Surgeons of Russia", (Moscow)

17. Ivanov S.N., MD, Russian Society of Cardiology, (Novosibirsk)

18. Kalashnikov S.V., PhD in Medical Sciences, (Moscow)

19. Kim A.I., DSc in Medical Sciences, "Association of Cardiovascular Surgeons of Russia", (Moscow)

20. Kovalev I.A., DSc in Medical Sciences, "Association of Pediatric Cardiologists of Russia", (Moscow)

21. Komissarov M.I., (Saint Petersburg)

22. Krivoshchekov E.V., DSc in Medical Sciences, (Tomsk)

23. Krupyanko S.M., MD, Association of Pediatric Cardiologists of Russia, (Moscow)

24. Kupryashov A.A., DSc in Medical Sciences, (Moscow)

25. Levchenko E.G., (Moscow)

26. Lezhnev A.A., (Moscow)

27. Martynyuk T.V., Russian Society of Cardiology, (Moscow)

28. Movsesyan R.R., DSc in Medical Sciences, "Association of Cardiovascular Surgeons of Russia", (Saint Petersburg)

29. Moiseeva O.M., MD, Russian Society of Cardiology, (Saint Petersburg)

30. Nalimov K.A., (Khabarovsk)

31. Nikiforov A.B., (Moscow)

32. Petrushenko D.Yu., (Kazan)

33. Plotnikov M.V., Candidate of Medical Sciences, (Astrakhan)

34. Podoksenov A.Yu., (Moscow)

35. Pursanov M.G., Doctor of Medical Sciences, (Moscow)

36. Svobodov A.A., Doctor of Medical Sciences, (Moscow)

37. Sinelnikov Yu.S., Doctor of Medical Sciences, (Perm)

38. Teplov P.V. (Krasnoyarsk)

39. Trunina I.I., Doctor of Medical Sciences, "Association of Pediatric Cardiologists of Russia", (Moscow)

40. Chernogrivov A.E., MD, Association of Cardiovascular Surgeons of Russia, (Moscow)

41. Shekhmametyev R.M., (Perm)

42. Yakovleva A.N., (Saint Petersburg)

There is no conflict of interest.

All members of the Working Group have confirmed that they have no financial support or conflicts of interest to disclose.

Appendix A2. Methodology for Developing Clinical Guidelines

Target audience for these clinical guidelines:

1. Pediatric Cardiologist

2. Cardiologist

3. Cardiovascular Surgeon

4. Surgeon

5. Ultrasound Diagnostics Physician

6. Pediatrician

7. X-ray Endovascular Diagnostics and Treatment Physician

During the development of the clinical guidelines, international scales for the levels of recommendation persuasiveness and levels of evidence reliability were used (Tables 1 and 2), as well as a new system of scales for the levels of evidence reliability (LER) and levels of recommendation persuasiveness (LRP) for therapeutic, rehabilitative, preventive, and diagnostic interventions (Tables 3, 4, and 5), introduced in 2018 by the Center for Healthcare Quality Assessment and Control of the Russian Ministry of Health. The National Guidelines were formulated based on ESC recommendations, taking into account national specifics, examination and treatment features, and the availability of medical care. For this reason, the text of these clinical guidelines simultaneously uses two scales for evaluating the reliability of evidence for recommendation theses: the ESC levels of evidence reliability with LRP and LER. ESC recommendation classes have been added to assess the necessity of executing the recommendation thesis.

Table 1. Classes of recommendations according to the European Society of Cardiology (ESC) guidelines.

Table 2. Levels of evidence reliability according to the European Society of Cardiology (ESC) guidelines.

Table 3. Scale for assessing the levels of evidence reliability (LER) for diagnostic methods (diagnostic interventions).

Table 4. Scale for assessing the levels of evidence reliability (LER) for methods of prevention, treatment, and rehabilitation (preventive, therapeutic, and rehabilitative interventions).

Table 5. Scale for assessing the levels of recommendation persuasiveness (LRP) for methods of prevention, diagnostics, treatment, and rehabilitation (preventive, diagnostic, therapeutic, and rehabilitative interventions).

Procedure for updating clinical guidelines.

The mechanism for updating clinical guidelines provides for their systematic revision at least once every three years, as well as upon the emergence of new evidence-based medicine data on the diagnosis, treatment, prevention, and rehabilitation of specific diseases, or in the presence of justified additions/comments to previously approved clinical guidelines, but no more frequently than once every 6 months.

Appendix A3. Reference Materials

1. On the Basics of Protecting the Health of Citizens in the Russian Federation (Federal Law No. 323-FZ of November 21, 2011)

2. Procedure for the Provision of Medical Care to Patients with Cardiovascular Diseases (Order of the Russian Ministry of Health No. 918n of November 15, 2012)

3. "On the Classification and Criteria Used in the Implementation of Medicosocial Expertise of Citizens by Federal State Institutions of Medicosocial Expertise" (Order of the Russian Ministry of Health No. 1024n of December 17, 2015)

Appendix B. Physician Action Algorithms

Appendix C. Patient Information

Aortic arch interruption (AAI) and double aortic arch (DAA) are congenital heart defects that belong to the group of congenital vascular pathologies of the aorta. These defects are rare, but of critical importance, since delayed diagnosis, especially in AAI, invariably leads to severe complications with a high risk of patient mortality. DAA is generally characterized by a more favorable prognosis; however, in the presence of severe obstruction of anatomical structures, particularly the tracheobronchial tree caused by this congenital heart defect, the prognosis also sharply deteriorates. AAI represents essentially the absence, to varying extents, of the tubular segment of the aorta. The lack of a functional lumen at the level of the aortic arch leads to potentially severe hemodynamic disorders. Impaired blood flow through the aortic arch is accompanied by the cessation of blood supply to the lower half of the body unless the function of the arterial duct is preserved. Only in such a situation can the condition of a patient with AAI be considered relatively compensated. However, this is an extremely unstable hemodynamic state, since closure of the PDA can occur at any moment without the administration of special medications. The latter include prostaglandins E, the infusion of which is continuously required in such patients until surgical intervention is performed. Obviously, the administration of such drugs must be timely, which is only possible with an accurately established diagnosis. Modern diagnostic capabilities make it possible to suspect this, like many other congenital heart defects, as early as the prenatal period. However, despite the high resolving power of modern ultrasound equipment, cases of delayed diagnosis are still possible. Nevertheless, timely registration of pregnant women and performance of mandatory and, if necessary, expert prenatal fetal examinations make it possible to establish the diagnosis with an accuracy of over 90%.

Surgical treatment for this pathology is currently developed at a high level. Primary radical correction is the intervention of choice and is accompanied by quite acceptable results. It should still be borne in mind that congenital heart defects are often combined with concomitant defects of the heart and vessels. This fact, as well as the frequent need to use additional materials during radical correction and to create anastomoses on the neo-aortic arch itself, determines the high frequency of subsequent reoperations. The probability of reoperation is not 100%, but it increases with age and as the child grows. Mainly, reoperations are caused by the recurrence of obstruction or stenosis on the aorta. At the same time, when it comes to reoperation, these can often be endovascular interventions, which do not require open access and are minimally invasive.

DAA is a duplication of the main trunk vessel, the aorta, as the name implies, which leads to the formation of a complete vascular ring and subsequent problems.

Unlike AAI, this defect is not PDA-dependent. Nevertheless, the appearance of symptoms caused by the presence of this complete vascular ring in infancy will often indicate the severity of the disease and a grim prognosis in the absence of timely treatment.

In the absence of a clear clinical picture and complaints, surgical treatment in such a case would be performed for preventive rather than clinical reasons. Nevertheless, the very fact of the presence of symptoms, even moderate ones, is a prognostic sign of the development of severe complications in the future. Only in adult patients in whom this congenital heart defect is an incidental finding and in the absence of any symptoms may surgery not be indicated.

In any case, when indications are present, surgical treatment is the only method and makes it completely possible to eliminate the defect and its consequences. The operation to relieve DAA can be either open or using thoracoscopic techniques. In the absence of complications from the tracheobronchial tree in the form of pronounced deformation, the prognosis after surgery is usually favorable.

Appendix G. Assessment Scales, Questionnaires, and Other Evaluation Tools

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