A right-sided aortic arch is a rare congenital defect of the aorta. A 56-year-old Caucasian male patient was hospitalized with coronary artery disease (stable angina CCS II, postinfarction cardiosclerosis), stage II hypertension, impaired glucose tolerance and congestive heart failure NYHA class II. Contrast-enhanced ECG-gated multi-slice computed tomography was performed on Siemens SOMATOM Force Germany and revealed right-sided aortic arch, aberrant left subclavian artery with Kommerell’s diverticulum and kinking of the thoracic aorta. This case is an example of the great advantages of knowing human anatomy and embryology in clinical practice. Modern diagnostic modalities give an accurate information on congenital variants and anomalies of the aortic arch and its branch that is vital for vascular surgery in the thorax, head and neck region.
Alexander Mrochek1, Sergey Kabak2, Hanna Model3, Yuliya Melnichenko2, Tamara Kalenchic4, Natallia Didenko5
1 Republican Scientific and Practical Centre “Cardiology”, Cardiologist of the Ministry of Health of the Republic of Belarus, Academician of National Academy of Science of Belarus
2 Human Morphology Department, Belarusian State Medical University, Minsk, Belarus
3 Radiologist of the Republican Scientific and Practical Centre “Cardiology”, Minsk, Belarus
4 Medical Rehabilitation and Physiotherapy Department, Belarusian State Medical University, Minsk, Belarus
5 Center of Diagnostic and Rehabilitation of Gazprom transgaz, Moskow, Russian Federation
Sign up or Login
A left- or right-sided aortic arch (RSAA) refers to the position of the aortic arch in relation to the trachea (Miranda et al., 2014). The normal left aortic arch lies on the left of the trachea and courses over the left main bronchus. A RSAA refers to an aortic arch that courses and descends to the right side of the trachea.
A right-sided aortic arch is a rare congenital defect of the aorta and occurs in 0.05% to 0.1% of radiology series and in 0.04%-0.1% of autopsy series (Arazinska et al., 2017; Priya et al., 2018; Popieluszko et al., 2018). The real incidence of RSAA in the general population is unknown, but a rate of 1/1000 has been suggested by Achiron et al. (2002). The recent progress in perinatal medicine and imaging techniques had facilitated the prenatal diagnosis of this cardiovascular anomaly (Muraoka et al., 2018). RSAA was detected in 0.6% of all fetal cardiac examinations and to 5.0% of all cardiac abnormalities (Miranda et al., 2014). Abnormalities of aortic arch orientation are often associated with a variety of congenital heart defects (Tetralogy of Fallot and truncus arteriosus), as well as chromosomal abnormalities, such as DiGeorge syndrome (22q11 deletion) (Law and Mohan, 2019).
There are three main subtypes of RSAA according to Edwards’ model: type I – RSAA with mirror image branching; type II – RSAA with aberrant left subclavian artery (ALSA); and type III – RSAA with isolated subclavian artery. The most common subtype is type II, when the right common artery arises as the first branch and is followed by the right subclavian artery and the left common carotid artery while the left subclavian artery is the last branch and takes a retroesophageal course to reach on the left side (García-Guereta et al., 2016; Priya et al., 2018. The aberrant left subclavian artery has a variable descending: posterior to the esophagus in 80% of cases, anterior to the trachea in 5% of cases and just between the trachea and esophagus in 15% of cases (Tong et al., 2015). Edwards’ type II reveals cardiac anomalies only in 5-10% of cases, which are commonly diagnosed in newborns and young children and rarely become symptomatic in adults (Ebner et al., 2013). About half of the patients with right-sided aortic arch have an aberrant left subclavian artery, which may arise either directly from the aorta or from the Kommerell’s diverticulum (Tong et al., 2015). The complete vascular ring is formed by the segment of the ascending aorta anteriorly, Kommerell’s diverticulum posteriorly and the ligamentum arteriosum coursing on the left side of the trachea. Any symptoms, which result from an aberrant left subclavian artery, are associated with compression of the esophagus or trachea and are most likely to occur if its origin is dilated (Kakaria et al., 2008; Yang et al., 2009).
In this article, we report an asymptomatic patient with right-sided aortic arch in whom an aneurysm of the aberrant left subclavian artery was detected.
A 56-year-old Caucasian male patient was hospitalized in the Belarusian State Institution «Republican Scientific and Practical Centre «Cardiology» in 2018 for typical angina combined with shortness of breath upon walking about 1000 m and climbing stairs to the 4th floor. He had a history of an acute myocardial infarction in 2017. The patient provided the informed consent regarding radiological images, clinical assessment and publication of patient’s data.
He was diagnosed with chronic coronary artery disease (stable angina CCS II, postinfarction cardiosclerosis) based on typical clinical presentation, hypertension stage III, impaired glucose tolerance and congestive heart failure NYHA class II. Contrast-enhanced ECG-gated multi-slice computed tomography, performed on Siemens SOMATOM Force (Germany), revealed:
The right-sided aortic arch (Fig. 1) crossing the midline at the level of the Th4-Th5 vertebral bodies, following a retroesophageal path and continuing to the descending part of the aorta, which was situated on the left side of the vertebral column.
Kommerell’s diverticulum (Fig. 1), a bulbous formation at the point of origin of the aberrant left subclavian artery with a diameter of 36 mm.
Kinking of the thoracic aorta at the level of the arch (Fig. 1). The diameter of the aorta fell within the normal range: 26 mm at the level of the valve’s annulus; 36 mm at the level of the aortic sinuses; 25 mm at the level of the sinotubular junction and proximal ascending aorta was measured at 27 mm. The diameter of the thoracic region of the descending part of the aorta was expanded to 49 mm.
The branches of the aortic arch – the right subclavian artery, the right and left common carotid arteries – did not show any stenosis. The pulmonary trunk was not expanded. Our patient did not have any cardiac and vascular congenital abnormalities associated with RAA and aberrant LSCA.
The aberrant right subclavian artery accounts for 0.5-1.8% of the population as the most frequently encountered aortic arch anomaly (Polguj et al., 2013; Naqvi et al., 2017), while right-sided aortic arch and an aberrant origin of the left subclavian artery with Kommerell’s diverticulum is a rare congenital anatomical condition most often observed in adults (Silveira et al., 2019). In the current report, we presented a classic case of this malformation diagnosed accidentally in which the aberrant left subclavian artery arises from the retroesophageal diverticulum located behind the esophagus. The complete vascular ring encircling of trachea and esophagus was not formed, and therefore there were no clinical signs of esophageal compression. The approach to asymptomatic patients with vascular ring (VR) is controversial because this condition is usually diagnosed during pregnancy and affected individuals can remain asymptomatic for a long period of time (García-Guereta et al., 2016). Most centers perform some type of postnatal confirmatory tests of the VR, particularly echocardiography, but due to the limitations of echocardiography magnetic resonance imaging has been proposed.
Aneurysmal diverticulum itself can cause the compression of the esophagus or may rupture spontaneously (Priya et al., 2018). The diverticulum is usually resected in symptomatic patients and followed by the aortopexy of the arch. Alternatively, after the resection of diverticulum, the left subclavian artery can be re-anastomosed to the left carotid artery.
The embryological origin of the various anomalies of the aortic arch is based on the theory of the hypothetic double aortic arch, which was described by Edwards (Yoo et al., 2003; Hsu et al., 2011). The ascending (ventral) aorta is divided into two aortic arches, which surround each side of the trachea and esophagus and connect to form the descending (dorsal) aorta. A common carotid artery and subclavian artery are derived from each aortic arch. Normally, the regression occurs between the origin of right subclavian artery and descending aorta in the right ascending aorta. Thus, the normal aortic arch is formed. If the interruption presents between the left carotid artery and the left subclavian artery in the left aortic arch, it will form a right-sided aortic arch with the aberrant left subclavian artery. There can be a dilated segment at the proximal part of the ALSA. The proximal part of the aberrant artery carries the blood flow from the ductus arteriosus into the descending aorta; and, therefore, the proximal part of the aberrant artery is as wide as the ductus and descending aorta (Hsu et al., 2011).
This case is a clear example of the helpfulness of the human anatomy and embryology knowledge in clinical practice. Accurate information about congenital variants and anomalies of the aortic arch and its branch obtained with modern diagnostic imaging modalities is vital for vascular surgery in the thorax, head and neck region.
ACHIRON R, ROTSTEIN Z, HEGGESH J, BRONSHTEIN M, ZIMAND S, LIPITZ S, YAGEL S (2002) Anomalies of the fetal aortic arch: a novel sonographic approach to in-utero diagnosis. Ultrasound Obstet Gynecol, 20(6): 553-557.
ARAZIŃSKA A, POLGUJ M, SZYMCZYK K, KACZMARSKA M, TRĘBIŃSKI Ł, STEFAŃCZYK L (2017) Right aortic arch analysis – Anatomical variant or serious vascular defect? BMC Cardiovasc Disord, 17: 102.
EBNER L, HUBER A, CHRISTE A (2013) Right aortic arch and Kommerell’s diverticulum associated with acute aortic dissection and pericardial tamponade. Acta Radiol Short Rep, 2(1): 2047981613476283.
GARCÍA-GUERETA L, GARCÍA-CERRO E, BRET-ZURITA M (2016) Multidetector computed tomography for congenital anomalies of the aortic arch: vascular rings. Rev Esp Cardiol (Engl Ed), 69(7): 681-693.
HSU KC, TSUNG-CHE HSIEH C, CHEN M, TSAI HD (2011) Right aortic arch with aberrant left subclavian artery--prenatal diagnosis and evaluation of postnatal outcomes: Report of three cases. Taiw J Obstet Gynecol, 50: 353-358.
KAKARIA AK, SAWHNEY S, JAIN R (2008) Right aortic arch with aberrant left subclavian artery. Sultan Qaboos Univ Med J, 8(3): 356-357.
LAW MA, MOHAN J (2019) Right aortic arches. In: StatPearls. StatPearls Publishing, Treasure Island (FL).
MIRANDA JO, CALLAGHAN N, MILLER O, SIMPSON J, SHARLAND G (2014) Right aortic arch diagnosed antenatally: associations and outcome in 98 fetuses. Heart, 100 (1): 54-59.
MURAOKA M, NAGATA H, HIRATA Y, UIKE K, TERASHI E,MORIHANA E, OCHIAI M, FUJITA Y, KATO K, YAMAMURA K, OHGA S (2018) High incidence of progressive stenosis in aberrant left subclavian artery with right aortic arch. Heart Vessels, 33(3): 309-315.
NAQVI SEH, BEG MH, THINGAM SKS, ALI E (2017) Aberrant right subclavian artery presenting as tracheoesophagial fistula in a 50-year-old lady: Case report of a rare presentation of a common arch anomaly. Ann Pediatr Cardiol, 10(2): 190-193.
POLGUJ M, CHRZANOWSKI Ł, KASPRZAK JD, STEFAŃCZYK L, TOPOL M, MAJOS A (2014) The aberrant right subclavian artery (arteria lusoria): the morphological and clinical aspects of one of the most important variations – a systematic study of 141 reports. Sci World J, 2014: 292734.
POPIELUSZKO P, HENRY BM, SANNA B, HSIEH WC, SAGANIAK K, PĘKALA PA, WALOCHA JA, TOMASZEWSKI KA (2018) A systematic review and meta-analysis of variations in branching patterns of the adult aortic arch. J Vasc Surg, 68(1): 298-306.
PRIYA S, THOMAS R, NAGPAL P, SHARMA A, STEIGNER M (2018) Congenital anomalies of the aortic arch. Cardiovasc Diagn Ther, 8(Suppl 1): S26-S44.
SILVEIRA JV, JUNQUEIRA FP, SILVEIRA CG, CONSOLIM-COLOMBO FM (2019) Kommerell diverticulum: right aortic arch with anomalous origin of left subclavian artery and duplicity of right vertebral artery in a 16-year-old girl. Am J Case Rep, 20: 228-232.
TONG E, RIZVI T, HAGSPIEL KD (2015) Complex aortic arch anomaly: Right aortic arch with aberrant left subclavian artery, fenestrated proximal right and duplicated proximal left vertebral arteries – CT angiography findings and review of the literature. Neuroradiol J, 28(4): 396-403.
YANG MH, WENG ZC, WENG YG, CHANG H-H (2009) A right-sided aortic arch with Kommerell’s diverticulum of the aberrant left subclavian artery presenting with syncope. J Chin Med Assoc, 72: 275-277.
YOO SJ, MIN JY, LEE YH, ROMAN K, JAEGGI E, SMALLHORN J (2003) Fetal sonographic diagnosis of aortic arch anomalies. Ultrasound Obstet Gynecol, 22(5): 535-546.