Case Study
Unusual cause of absent pulse in one arm: Isolated subclavian artery
Asian Cardiovascular & Thoracic Annals 2015, Vol. 23(4) 439–442 ß The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0218492313513593 aan.sagepub.com
Sushil Azad, Munesh Tomar and Anil Bhan
Abstract Isolated origin of the subclavian artery is a congenital anomaly of the aortic arch in which one subclavian artery originates from the homolateral pulmonary artery through the ductus arteriosus. Isolated right subclavian artery with left-sided aortic arch is extremely rare. We report a case of isolated right subclavian artery from the right pulmonary artery via a right-sided ductus arteriosus in a 4-year-old girl. The child presented with subclavian pulmonary steal with perfusion of the right arm and lung from the right vertebral and carotid arteries. She underwent successful surgical repair.
Keywords Ductus arteriosus, patent, heart defects, congenital, subclavian artery
Introduction Isolation of the subclavian artery is an unusual anomaly in which a subclavian artery arises not from the aortic arch but from the homolateral pulmonary artery via an arterial duct.1 Such isolation most often occurs on the left side with a right aortic arch, and lesions frequently associated are tetralogy of Fallot and double-outlet right ventricle.2 Rarely, it is associated with d-transposition of the great arteries.3 Association with 22q11 deletion also been reported.4 Isolation of the right subclavian artery in a left aortic arch is extremely rare. We report the case of child with isolated right subclavian artery arising from the right pulmonary artery via a right-sided ductus arteriosus. The patient showed subclavian and pulmonary steal with perfusion of the right arm and lung from the right vertebral artery.
Case report A 4-year-girl, first in birth order and product of a fullterm normal vaginal delivery, was taken to a pediatrician due to recurrent cough and cold. The pediatrician noticed a murmur and advised a cardiology evaluation. Cardiac examination revealed mild cardiomegaly, normal first and second heart sounds, S3 at the apex, and a short grade 2/6 ejection systolic murmur at the left parasternal border. General examination revealed
a child of average growth (weight 14 kg) with no features of cardiac failure. Pulses in the right upper limb were very feeble while in the other 3 limbs, the pulses were normal. The temperature of the right upper limb was lower than in the rest of the body. An electrocardiogram showed sinus rhythm with a normal QRS axis (þ90 ). Chest radiography showed mild cardiomegaly and increased pulmonary blood flow. Echocardiography was performed using an IE33 (Phillips) with S12 and S8 broadband transducers from subcostal, apical, parasternal and suprasternal views. Echocardiography revealed a dilated left atrium and left ventricle (left ventricular end-diastolic dimension Z score þ3), intact interatrial and interventricular septum, and normal left and right ventricular outflow tracts. The pulmonary arteries were confluent and of adequate size. On color-flow mapping, low velocity blood flow joined the right pulmonary artery at its origin and continued to the base of the right subclavian artery. The aortic arch was left-sided and we were not able to demonstrate the bifurcation of the first Department of Pediatric Cardiology and Congenital Heart Disease, Medanta-The Medicity, Gurgaon, Haryana, India Corresponding author: Sushil Azad, MD, FNB, Department of Pediatric Cardiology and Congenital Heart Disease, Medanta-The Medicity, Sector-38 Gurgaon, Haryana, India. Email: [email protected]
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Figure 1. Computed tomography-angiography demonstrating isolated origin of the right subclavian artery (RSCA) from the pulmonary artery (RPA) via a right-sided patent ductus arteriosus (PDA).
arch branch. There was no significant flow reversal in the aortic arch. We made a diagnosis of right-sided ductus. Computed tomography (CT)-angiography was carried out to define the anatomy. On CT-angiography, there was isolation of the right subclavian artery and it was connected to the right pulmonary artery origin by a right-sided patent ductus arteriosus (Figure 1). Multiple collaterals from the vertebral and carotid arteries were filling the right subclavian artery and then the pulmonary artery, leading to volume overload of the left atrium and left ventricle and causing underperfusion of the right arm. Cardiac catheterization for hemodynamic assessment revealed normal pulmonary arterial and ventricular filling pressures. Angiogram findings revealed the right carotid artery to be the first branch from the arch (Figure 2), and direct injection via the catheter in the right ductus through the pulmonary artery revealed filling of the right pulmonary artery (Figure 3). The right subclavian artery could not be visualized well due to rapid runoff The child underwent surgery. The subclavian artery was detached from the pulmonary artery and anastomosed to the ascending aorta. Immediately after surgery, both arm temperatures and pulses became normal. CT-angiography one week later revealed normal filling of the right subclavian artery from the ascending aorta (Figure 4).
Figure 2. Aortogram showing a normal arch with the origin of the right carotid as the first branch from the arch. The right subclavian artery is not seen arising from the arch.
Discussion Complete isolation of the subclavian artery is an uncommon congenital anomaly of the aortic arch system, defined as a loss of continuity between one subclavian artery and the aorta, with persistent connection to the homolateral pulmonary artery through a patent or non-patent ductus arteriosus.1 Embryologically, isolation of the right subclavian artery from the right pulmonary artery with a left aortic arch requires regression
Downloaded from aan.sagepub.com at NORTH DAKOTA STATE UNIV LIB on July 2, 2015
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of two levels in the hypothetical arch system of Edwards. One level is the right arch between the right common carotid and right subclavian arteries, the other is the right dorsal aortic root distal to the arterial duct. No vascular ring exists in this situation.5 Isolation of the right subclavian artery is far less common than isolation of the left subclavian artery. The isolated artery is usually supplied by collaterals from the vertebral artery, the reverse flow of which is responsible for cerebral symptoms. However, these symptoms are uncommon in children. Steal to the pulmonary circulation is dependent on pulmonary arterial pressures. If pulmonary arterial pressures are high due to an associated leftto-right shunt, a right-to-left shunt occurs through the ductus, leading to cyanosis of the arm.6 When there is
Figure 3. Angiogram with the catheter in the right ductus arteriosus (PDA) from the pulmonary artery (RPA), filling the right subclavian artery (RSCA).
no associated intracardiac anomaly, isolation of the subclavian artery presents with a left-to-right shunt and steal from the cerebral circulation with additional steal from the arms to the lungs, leading to arm ischemia, or it may be completely asymptomatic. Absence of pulses in the limb with the involved artery is the important clinical finding. If there is an associated intracardiac defect leading to pulmonary arterial hypertension, one finds good volume pulses with cyanosis involving that limb. Echocardiography provides adequate information in most cases, but if it is inconclusive, CT-angiography is very helpful. Defining arch anatomy along with arch branches by color-flow mapping is important in evaluating a child with a suspected congenital heart defect. When there is unusual duct anatomy, as in our case, the laterality and branching pattern of the aortic arch should be carefully evaluated. The management of this condition is surgical reimplantation of the subclavian artery along with correction of the associated intracardiac malformation if present.7 There are reports of transcatheter closure of the ductus arteriosus, resulting in improved hemodynamics.8 A transcatheter approach was not considered in this case because of the possibility of subclavian steal syndrome, thus the right subclavian artery was implanted to the ascending aorta to prevent the steal phenomenon. Isolation of the subclavian artery is a rare vascular anomaly, and suspicion can be raised on clinical evaluation only if one checks the pulse, temperature, and color in all 4 limbs. Echocardiography with special focus on the arch anatomy is the diagnostic modality. Cardiac catheterization, CT-angiography, and cardiac
Figure 4. Postoperative computed tomography-angiography showing the anastomosis of the right subclavian artery (RSCA) to the ascending aorta (arrow).
Downloaded from aan.sagepub.com at NORTH DAKOTA STATE UNIV LIB on July 2, 2015
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magnetic resonance imaging may be used to further define the anatomy before intervention. Surgical correction is the treatment of choice. Funding This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
Conflicts of interest statement None declared.
References 1. Stewart JR, Kincaid OW, Edwards JE. Malformations with left aortic arch (group II). ‘‘Isolation’’ of the right subclavian artery from aorta. In: An atlas of vascular rings and related malformations of the aortic arch system. 1st ed. Springfield, IL:Charles C. Thomas, 1964:76–9. 2. Plauth WH Jr, Nugent EW, Schlant RC, et al. congenital heart disease. In: Hurst JW (ed.) The heart, arteries and veins, 5th ed. New York: McGraw-Hill, 1982, p. 671.
3. Hofbeck M, Rupprecht T, Reif R and Singer H. Faulty origin of the right subclavian artery from pulmonary artery: a rare cause of subclavian steal syndrome in childhood. Monatsschr Kinderheilkd 1991; 139: 363–365. 4. Miller SG, Campbell MJ, Barker PC and Hill KD. Isolated right subclavian artery arising from right pulmonary artery via a right-sided ductus arteriosus with associated pulmonary steal phenomenon. Cardiol Young 2012; 22: 216–218. 5. Edwards JE. Anomalies of the aortic arch system. Birth Defects 1977; 13: 47–63. 6. Nath PH, Castaneda-Zuniga W, Zollikofer C, et al. Isolation of a subclavian artery. AJR Am J Roentgenol 1981; 137: 683–688. 7. McElhinney DB, Silverman NH, Brook MM, Reddy VM and Hanley FL. Rare form of isolation of subclavian artery: echocardiographic diagnosis and surgical considerations. Cardiol Young 1998; 8: 344–351. 8. Koneti NR, Qureshi SA and Sivakumar K. Catheter intervention for ‘‘double steal’’ from isolation of the subclavian artery associated with patent arterial duct. Cardiol Young 2013; 6: 1–4.
Downloaded from aan.sagepub.com at NORTH DAKOTA STATE UNIV LIB on July 2, 2015
Unusual cause of absent pulse in one arm: Isolated subclavian artery
Asian Cardiovascular & Thoracic Annals 2015, Vol. 23(4) 439–442 ß The Author(s) 2013 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav DOI: 10.1177/0218492313513593 aan.sagepub.com
Sushil Azad, Munesh Tomar and Anil Bhan
Abstract Isolated origin of the subclavian artery is a congenital anomaly of the aortic arch in which one subclavian artery originates from the homolateral pulmonary artery through the ductus arteriosus. Isolated right subclavian artery with left-sided aortic arch is extremely rare. We report a case of isolated right subclavian artery from the right pulmonary artery via a right-sided ductus arteriosus in a 4-year-old girl. The child presented with subclavian pulmonary steal with perfusion of the right arm and lung from the right vertebral and carotid arteries. She underwent successful surgical repair.
Keywords Ductus arteriosus, patent, heart defects, congenital, subclavian artery
Introduction Isolation of the subclavian artery is an unusual anomaly in which a subclavian artery arises not from the aortic arch but from the homolateral pulmonary artery via an arterial duct.1 Such isolation most often occurs on the left side with a right aortic arch, and lesions frequently associated are tetralogy of Fallot and double-outlet right ventricle.2 Rarely, it is associated with d-transposition of the great arteries.3 Association with 22q11 deletion also been reported.4 Isolation of the right subclavian artery in a left aortic arch is extremely rare. We report the case of child with isolated right subclavian artery arising from the right pulmonary artery via a right-sided ductus arteriosus. The patient showed subclavian and pulmonary steal with perfusion of the right arm and lung from the right vertebral artery.
Case report A 4-year-girl, first in birth order and product of a fullterm normal vaginal delivery, was taken to a pediatrician due to recurrent cough and cold. The pediatrician noticed a murmur and advised a cardiology evaluation. Cardiac examination revealed mild cardiomegaly, normal first and second heart sounds, S3 at the apex, and a short grade 2/6 ejection systolic murmur at the left parasternal border. General examination revealed
a child of average growth (weight 14 kg) with no features of cardiac failure. Pulses in the right upper limb were very feeble while in the other 3 limbs, the pulses were normal. The temperature of the right upper limb was lower than in the rest of the body. An electrocardiogram showed sinus rhythm with a normal QRS axis (þ90 ). Chest radiography showed mild cardiomegaly and increased pulmonary blood flow. Echocardiography was performed using an IE33 (Phillips) with S12 and S8 broadband transducers from subcostal, apical, parasternal and suprasternal views. Echocardiography revealed a dilated left atrium and left ventricle (left ventricular end-diastolic dimension Z score þ3), intact interatrial and interventricular septum, and normal left and right ventricular outflow tracts. The pulmonary arteries were confluent and of adequate size. On color-flow mapping, low velocity blood flow joined the right pulmonary artery at its origin and continued to the base of the right subclavian artery. The aortic arch was left-sided and we were not able to demonstrate the bifurcation of the first Department of Pediatric Cardiology and Congenital Heart Disease, Medanta-The Medicity, Gurgaon, Haryana, India Corresponding author: Sushil Azad, MD, FNB, Department of Pediatric Cardiology and Congenital Heart Disease, Medanta-The Medicity, Sector-38 Gurgaon, Haryana, India. Email: [email protected]
Downloaded from aan.sagepub.com at NORTH DAKOTA STATE UNIV LIB on July 2, 2015
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Asian Cardiovascular & Thoracic Annals 23(4)
Figure 1. Computed tomography-angiography demonstrating isolated origin of the right subclavian artery (RSCA) from the pulmonary artery (RPA) via a right-sided patent ductus arteriosus (PDA).
arch branch. There was no significant flow reversal in the aortic arch. We made a diagnosis of right-sided ductus. Computed tomography (CT)-angiography was carried out to define the anatomy. On CT-angiography, there was isolation of the right subclavian artery and it was connected to the right pulmonary artery origin by a right-sided patent ductus arteriosus (Figure 1). Multiple collaterals from the vertebral and carotid arteries were filling the right subclavian artery and then the pulmonary artery, leading to volume overload of the left atrium and left ventricle and causing underperfusion of the right arm. Cardiac catheterization for hemodynamic assessment revealed normal pulmonary arterial and ventricular filling pressures. Angiogram findings revealed the right carotid artery to be the first branch from the arch (Figure 2), and direct injection via the catheter in the right ductus through the pulmonary artery revealed filling of the right pulmonary artery (Figure 3). The right subclavian artery could not be visualized well due to rapid runoff The child underwent surgery. The subclavian artery was detached from the pulmonary artery and anastomosed to the ascending aorta. Immediately after surgery, both arm temperatures and pulses became normal. CT-angiography one week later revealed normal filling of the right subclavian artery from the ascending aorta (Figure 4).
Figure 2. Aortogram showing a normal arch with the origin of the right carotid as the first branch from the arch. The right subclavian artery is not seen arising from the arch.
Discussion Complete isolation of the subclavian artery is an uncommon congenital anomaly of the aortic arch system, defined as a loss of continuity between one subclavian artery and the aorta, with persistent connection to the homolateral pulmonary artery through a patent or non-patent ductus arteriosus.1 Embryologically, isolation of the right subclavian artery from the right pulmonary artery with a left aortic arch requires regression
Downloaded from aan.sagepub.com at NORTH DAKOTA STATE UNIV LIB on July 2, 2015
Azad et al.
441
of two levels in the hypothetical arch system of Edwards. One level is the right arch between the right common carotid and right subclavian arteries, the other is the right dorsal aortic root distal to the arterial duct. No vascular ring exists in this situation.5 Isolation of the right subclavian artery is far less common than isolation of the left subclavian artery. The isolated artery is usually supplied by collaterals from the vertebral artery, the reverse flow of which is responsible for cerebral symptoms. However, these symptoms are uncommon in children. Steal to the pulmonary circulation is dependent on pulmonary arterial pressures. If pulmonary arterial pressures are high due to an associated leftto-right shunt, a right-to-left shunt occurs through the ductus, leading to cyanosis of the arm.6 When there is
Figure 3. Angiogram with the catheter in the right ductus arteriosus (PDA) from the pulmonary artery (RPA), filling the right subclavian artery (RSCA).
no associated intracardiac anomaly, isolation of the subclavian artery presents with a left-to-right shunt and steal from the cerebral circulation with additional steal from the arms to the lungs, leading to arm ischemia, or it may be completely asymptomatic. Absence of pulses in the limb with the involved artery is the important clinical finding. If there is an associated intracardiac defect leading to pulmonary arterial hypertension, one finds good volume pulses with cyanosis involving that limb. Echocardiography provides adequate information in most cases, but if it is inconclusive, CT-angiography is very helpful. Defining arch anatomy along with arch branches by color-flow mapping is important in evaluating a child with a suspected congenital heart defect. When there is unusual duct anatomy, as in our case, the laterality and branching pattern of the aortic arch should be carefully evaluated. The management of this condition is surgical reimplantation of the subclavian artery along with correction of the associated intracardiac malformation if present.7 There are reports of transcatheter closure of the ductus arteriosus, resulting in improved hemodynamics.8 A transcatheter approach was not considered in this case because of the possibility of subclavian steal syndrome, thus the right subclavian artery was implanted to the ascending aorta to prevent the steal phenomenon. Isolation of the subclavian artery is a rare vascular anomaly, and suspicion can be raised on clinical evaluation only if one checks the pulse, temperature, and color in all 4 limbs. Echocardiography with special focus on the arch anatomy is the diagnostic modality. Cardiac catheterization, CT-angiography, and cardiac
Figure 4. Postoperative computed tomography-angiography showing the anastomosis of the right subclavian artery (RSCA) to the ascending aorta (arrow).
Downloaded from aan.sagepub.com at NORTH DAKOTA STATE UNIV LIB on July 2, 2015
442
Asian Cardiovascular & Thoracic Annals 23(4)
magnetic resonance imaging may be used to further define the anatomy before intervention. Surgical correction is the treatment of choice. Funding This research received no specific grant from any funding agency in the public, commercial, or not-for-profit sectors.
Conflicts of interest statement None declared.
References 1. Stewart JR, Kincaid OW, Edwards JE. Malformations with left aortic arch (group II). ‘‘Isolation’’ of the right subclavian artery from aorta. In: An atlas of vascular rings and related malformations of the aortic arch system. 1st ed. Springfield, IL:Charles C. Thomas, 1964:76–9. 2. Plauth WH Jr, Nugent EW, Schlant RC, et al. congenital heart disease. In: Hurst JW (ed.) The heart, arteries and veins, 5th ed. New York: McGraw-Hill, 1982, p. 671.
3. Hofbeck M, Rupprecht T, Reif R and Singer H. Faulty origin of the right subclavian artery from pulmonary artery: a rare cause of subclavian steal syndrome in childhood. Monatsschr Kinderheilkd 1991; 139: 363–365. 4. Miller SG, Campbell MJ, Barker PC and Hill KD. Isolated right subclavian artery arising from right pulmonary artery via a right-sided ductus arteriosus with associated pulmonary steal phenomenon. Cardiol Young 2012; 22: 216–218. 5. Edwards JE. Anomalies of the aortic arch system. Birth Defects 1977; 13: 47–63. 6. Nath PH, Castaneda-Zuniga W, Zollikofer C, et al. Isolation of a subclavian artery. AJR Am J Roentgenol 1981; 137: 683–688. 7. McElhinney DB, Silverman NH, Brook MM, Reddy VM and Hanley FL. Rare form of isolation of subclavian artery: echocardiographic diagnosis and surgical considerations. Cardiol Young 1998; 8: 344–351. 8. Koneti NR, Qureshi SA and Sivakumar K. Catheter intervention for ‘‘double steal’’ from isolation of the subclavian artery associated with patent arterial duct. Cardiol Young 2013; 6: 1–4.
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