Analiză clinică a malformațiilor arcului aortic: perspective din multiple studii de caz

Introduction

Aortic arch malformations are congenital anomalies that can occur during the formation of the aortic arch. Most of these are asymptomatic, and are considered ana­to­mical variants, but some present significant car­dio­­res­piratory impairment that requires treatment⁽¹⁾.

These congenital heart defects are typically identified using imaging techniques like CT angiography, MRI or echocardiography. Echocardiography is often used for initial screening in pediatric cases, while CT and MRI offer detailed imaging useful for surgical planning, especially in symptomatic or complex cases. For instance, CT angiography provides high-resolution images, though it involves radiation exposure, whereas MRI avoids radiation, but may require sedation for younger children⁽²⁾. The incidence of aortic arch malformations is very low (<1%), and it is often associated with genetic alterations like the 22q11.2 deletion syndrome⁽³⁾. Because there are such few cases, clinicians may experience difficulties in managing this type of pathology. Our primary goal is to present the clinical manifestation and management of different types of aortic arch malformations. Another important topic is to draw attention on the low number of such cases and on the necessity of documentation to further improve the treatment. Also, we intend to compare statistical data from our study with data from other studies to see if we find a correlation.

Materials and method

We analyzed the cases of 70 patients admitted to our clinic between 1.01.2023 and 10.12.2023, who were diagnosed with specific aortic malformations. Of these, we selected the cases that involved aortic arch malformations, resulting in a total of six cases.

The six cases are categorized as follows, in Figure 1.

All six patients have also associated cardiac malformations. An interesting fact to consider is the presence of heart failure, which coincides with the impact of these defects on heart function. Below are the specific details of these cases, including relevant comparisons and associations.

Case 1: Double aortic arch

Anamnesis

A 3-month-old female patient, known for recurrent respiratory infections and laryngotracheomalacia, presented with a new respiratory infection. Imaging investigations revealed a complex vascular malformation, leading to the patient’s transfer to the Pediatric Cardiology Clinic.

Clinical and paraclinical examinations

Echocardiography confirmed the following diagno­stics: left ventricular diastolic dysfunction, patent fora­men ovale, grade II mitral regurgitation, grade II tricuspid regurgitation, concentric hypertrophic cardiomyopathy and aortic arch anomaly.

To determine the specific type of aortic arch anomaly, a CT scan was performed, which confirmed the presence of a double aortic arch associated with left-sided aortic arch hypoplasia and a dominant right aortic arch; the right subclavian artery and the common carotid artery originated from the dominant aortic arch.

Treatment

A surgical intervention was performed to correct the double aortic arch defect. The patient was left with a dominant right aortic arch and class III Ross heart failure.

Case particularities

Recurrent respiratory infections in this infant were a key factor that guided us towards investigating a potential cardiac malformation. The cardiothoracic CT scan provided detailed information that supported the echocardiography findings.

It can be stated that the surgical intervention aimed to restore the aortic arch function as close as possible to its physiological state, utilizing the dominant right aortic arch.

Case 2: Interrupted aortic arch

Anamnesis

A male patient was first evaluated at our clinic at the age of 3 months old, in 2021, based on the recommendation of his family physician. He was diagnosed with an interrupted aortic arch, pulmonary hypertension, patent ductus arteriosus, a large ventricular septal defect, hypoplasia of the ascending aorta, left ventricular hypertrophy and class IV Ross heart failure. CT imaging confirmed the diagnosis of an interrupted aortic arch. Surgical intervention was promptly recommended, and the patient was scheduled for surgery at a center that accepted the transfer. The surgery was successfully completed, and the patient returned for annual checkups at our clinic, with the most recent follow-up in March 2023.

Clinical and paraclinical examinations

The patient had presented with a respiratory infection two days prior to hospitalization.

Echocardiography showed the reconstruction of the aortic arch and a large ventricular septal defect closed with a patch. The genetic consultation revealed a microduplication in the 22q11.21 region.

Treatment

Before the surgical intervention, the patient was being treated with alprostadil. The patient continued the treatment with furosemide and spironolactone. Close monitoring of the case was recommended.

Case particularities

Genetic consultation was conducted, with suspicion of DiGeorge syndrome (microdeletion of the 22q11.2 region). The MLPA test revealed a microduplication in the same region, representing one of the cases with manifestations similar to DiGeorge syndrome.

Following the surgical intervention, the degree of heart failure decreased from class IV to class II-III Ross. Similar to the previous case, the CT examination confirmed the diagnosis.

Case 3 and Case 4: Right aortic arch

Anamnesis

An 11-year-old female patient, diagnosed in 2019 with severe cardiac malformation (right aortic arch, pulmonary hypertension, malposition of major vessels, complete atrioventricular canal, cardiomegaly and class IV NYHA heart failure) was admitted to our clinic following a respiratory infection. A 1-month-old male patient was transferred to the regional hospital at 14 days of age with generalized cyanosis and observed dextrocardia. He was subsequently transferred to our clinic for further investigation.

Clinical and paraclinical examinations

Echocardiography revealed changes indicative of severe pulmonary hypertension. The need for a cardiac CT and cardiac catheterization was established to evaluate pulmonary pressure and determine the appropriate treatment for pulmonary hypertension. Clinically, the patient presented with a severe condition, cyanotic skin, SpO₂of 88% and a heart rate of 155 bpm.

Echocardiography diagnosed dextrocardia, complete atrioventricular canal, right aortic arch, transposition of the great vessels, severe pulmonary hypoplasia and stenosis and persistent ductus arteriosus, along with class IV Ross heart failure.

Angio-CT confirmed these diagnostics, providing detailed information on the severity of the defects and concluding with a diagnosis of severe complex malformation, with a recommendation for palliative surgical intervention.

Treatment

The patient was scheduled for a cardiovascular surgery consultation to initiate the process for surgical intervention. The patient was treated in our clinic with the aim of obtaining approval for emergency surgical intervention. The ductus arteriosus was maintained with alprostadil.

Approval for transfer to an out-of-state clinic for the surgical procedure was obtained, but, in the meantime, the patient experienced a cardiac arrest that didn’t respond to resuscitation efforts, and passed away five days before the transfer.

Case particularities

Both patients presented with a severe general condition, but not due to the right aortic arch per se, rather because of the associated cardiac defects.

The case of the 11-year-old patient highlights the need for early consultation in children with symptoms suggestive of cardiac pathology, thereby preventing the progression of the condition through early treatment.

In the case of the 1-month-old patient, efforts were made to maintain a stable condition while awaiting transfer to a facility where the surgical intervention could be performed. Unfortunately, the severity of the cardiac malformations did not allow for the maintenance of vital functions long enough to undertake such an extensive procedure.

Case 5 and Case 6: Coarctation of the aorta

Anamnesis

An 11-year-old male patient, diagnosed in 2017 with an aortic cusp coaptation anomaly, a small secundum atrial septal defect (ASD) and a broad aortic coarctation, presented for a cardiology follow-up. A 4-year-old male patient, known with severe aortic coarctation (surgically corrected with a residual gradient), mitral valve prolapse, moderate pulmonary hypertension, a small secundum atrial septal defect (ASD), class I-II NYHA heart failure and mild aortic valve hypoplasia, presented for a cardiology follow-up.

Clinical and paraclinical examinations

Abdominal and thyroid ultrasound showed no pathological changes. Blood tests revealed low levels of iron in serum and hypocalcemia. Echocardiography, in addition to the previously mentioned diagnoses, also revealed a broad aortic coarctation. Clinically, it should be noted that the patient presented with skin lesions characteristic of chickenpox, which was confirmed through an infectious disease consultation. Echocardiography showed the aforementioned diagnoses and an improvement in pulmonary hypertension, now presenting in a mild form.

Treatment

The patient was receiving treatment with calcium and iron supplements to address the deficiencies. A follow-up appointment was recommended in six months. Given the presence of chickenpox, the mother requested the child’s discharge from the hospital.

Case particularities

Both cases involved aortic coarctation of varying degrees. We can observe that, in the patient with broad aortic coarctation, surgical intervention was not necessary. The two patients continue to return for regular checkups to monitor their cardiac condition and to diagnose or treat any additional conditions that may arise over time. 

Discussion

Part I: Statistical information about aortic arch malformations

The first classification of aortic arch malformations was made by James Stewart and his colleagues in 1964. This classification divides malformations into four major groups: double arch aortic anomalies, left aortic arch anomalies, right aortic arch anomalies and other anomalies of the aortic arch⁽⁶⁾. Later, with advancements in imaging diagnostic methods, more previously unrecognized aortic arch defects were identified.

Our article focuses on the analysis of cases involving aortic arch malformations from a wide spectrum of patients who were admitted to our clinic during 2023.

Over the course of 11 months and 10 days, 3256 patients with various cardiac pathologies were consulted. Among them, 70 patients had aortic malformations, with only 8.57% presenting with an aortic arch malformation.

In 2023, Tamohamed and Umapathi reported that double aortic arch is an extremely rare defect with a very low incidence (<1%) due to the small number of cases⁽⁷⁾. Our study reached a similar conclusion, with the percentage of cases involving a double aortic arch being 0.0307%.

The same percentage also applies to cases with an interrupted aortic arch. It is important to note that the introduction of prostaglandin E1 in the late 1970s revolutionized the management of interrupted aortic arch. Additionally, studies highlight the necessity of further investigation in these patients due to the high incidence of DiGeorge syndrome⁽⁸⁾.

According to the study conducted by Law and Mohan in 2023, right aortic arch malformations occur in 0.01% to 0.1% of the population⁽⁹⁾, which aligns with the results from our clinic (0.0614%). Similarly, as observed in Cases 3 and 4, associated malformations such as transposition of the great vessels are also described.

Although the aforementioned defects represent rare cases of congenital heart malformations, the same cannot be said for aortic coarctation. According to the study published by Kim et al. in 2020, aortic coarctation accounts for 6-8% of all congenital heart defects, and has an incidence of 0.04%, with a predominant male-to-female ratio of 2:1⁽¹⁰⁾. Our study reveals a percentage of 0.0614% among the cases during the specified time period, but we cannot confirm whether aortic coarctation is indeed responsible for 6-8% of congenital heart defects.

As seen in the classification described in this study, there is a wide variety of aortic arch malformations⁽¹¹⁾. However, in practice we encounter a much smaller number, and some defects have a higher incidence than others. We cannot accurately estimate the frequency of certain defects within a patient population due to the small number of cases.

Part II: Clinical aspects of aortic arch malformations

All six cases described various medical conditions, not solely an aortic arch malformation. Patients with congenital heart disease often have associated congenital anomalies, which need to be thoroughly investigated⁽¹²⁾.

One of the most efficient ways to investigate these anomalies is through computed tomography (CT) or angio-CT⁽¹³⁾. Four out of six patients were diagnosed using CT/angio-CT. Echocardiography was sufficient to diagnose coarctation of the aorta in our cases; however, multiple severe aortic arch malformations can be challenging to assess using echocardiography alone⁽¹⁴⁾.

Atrial septal defect, atrioventricular canal, pulmonary hypertension and heart failure were the primary findings associated with aortic arch malformations in our study. Multiple studies have found a correlation between congenital heart diseases, such as those observed in our patients, and an increased risk of developing severe conditions like stroke or atherosclerosis over time^(15,16).

Pulmonary hypertension can be found in pediatric patients with congenital heart diseases, and it is often coupled with malnutrition and vitamin deficiencies, which can exacerbate the condition⁽¹⁷⁾. In the majority of the cases presented, the curative treatment was surgical, with a recommendation for periodic follow-up to prevent complications⁽¹⁸⁾.

Limitations of our study: our center had only six (of 3256) patients with aortic arch malformations and, because of this, we could not provide important statistical data.

Prospects for further research: our study highlighted the necessity of analyzing data from multiple cases (not just a few) to identify meaningful correlations and outcomes that could support clinicians in the future. Collaboration between multiple centers could provide a larger patient population for study. Another interesting topic for research should be assessment of the influence of aortic arch malformations diagnosed at birth as a risk factor for the development of other conditions throughout life.

Conclusions

At present, there are not many studies available on the incidence of aortic arch malformations due to the relatively small number of cases. Our study reveals a prevalence of 0.184% for aortic arch malformations over a period of 11 months and 10 days.

Despite the relatively small number of cases with these malformations, our study can assert that, over the course of a year, specialists in this field are likely to encounter at least a few patients with these cardiac defects, making it essential to be familiar with the management of these conditions.

The incidence of these types of malformations is below 1%, a fact confirmed by multiple studies and consistent with the values observed in our research. Patients with one of these defects often present with additional malformations, as seen in the cases we have reported. The severity of each case is determined by the cumulative impact of these defects on the cardiovascular system. A close correlation is observed between aortic arch defects and genetic syndromes, such as DiGeorge syndrome, which is frequently associated with interrupted aortic arch (a finding that is also present in our study).

Prostaglandin E1 plays an essential role in maintaining hemodynamic stability in preparation for surgical intervention in patients with interrupted aortic arch.

Echocardiography and CT scans are two crucial investigations for the diagnosis and monitoring of patients with aortic arch malformations. These modalities have enabled a better understanding of the structural changes in the aortic arch, leading to more detailed classifications than the one described by Stewart et al. in 1964⁽¹⁹⁾.

Patients with aortic arch malformations often have other associated cardiovascular conditions that require monitoring. These conditions can pose risks for severe complications over time.

It has been challenging to establish precise values regarding the percentage of certain rare types of aortic arch malformations due to the lack of documented cases, a point supported by our study, which identified only six cases of aortic arch malformations out of a population of 3256 patients.

Author contributions. All authors contributed equally.

Funding. This research received no external funding.

Institutional Review Board Statement. The study was conducted in accordance with the Declaration of Helsinki, and approved by the Ethics Committee of the “Sf. Maria” Emergency Clinical Hospital for Children, Iaşi, Romania (protocol code 38794/20.11.2024).

Informed consent statement. The informed consent was obtained from all subjects involved in the study.

Conflicts of interest. The authors declare no conflicts of interest.

Autor corespondent:  Dana-Elena Mîndru E-mail: eledanamindru@gmail.com

CONFLICT OF INTEREST: none declared.

FINANCIAL SUPPORT: none declared.

This work is permanently accessible online free of charge and published under the CC-BY.