Pamela Duke, M.D., Department of Medicine
Neil Epstein, M.D., Director of Radiology
Arshad Quadri, M.D., Cardiovascular Surgery

Developmental anomalies of the aortic arch usually manifest themselves in early childhood. The most common of these are a double aortic arch, a right aortic arch with a constricting left ligamentum arteriosum, and an anomalous origin of the right subclavian artery. These create a "vascular ring" around the esophagus and trachea that may cause breathing and swallowing difficulties due to constriction of the esophagus or trachea. (1,2) In infants, clinical manifestations include cyanosis and feeding problems. Vascular rings infrequently become symptomatic in adults.

Case Report

An 18 year old male presented to the Saint Francis Hospital Adult Walk-in Clinic with complaints of a "lump in his throat", difficulty swallowing, and occasional shortness of breath. Two months prior to coming to the clinic, the patient had been involved in a motor vehicle accident and had sustained an injury to his chest wall. Shortly after this, he was admitted to a community hospital with the chief complaint of chest pains, dysphagia, and occasional shortness of breath. An echocardiogram was reported to be normal, and he was treated for pericarditis with ibuprofen. However, his dysphagia, particularly for solid foods, continued after discharge and reportedly lost ten pounds over a four week period.

The patient denied vomiting or other gastrointestinal symptoms. His previous medical history was unremarkable with no childhood cardiopulmonary problems. There was no history of allergies and he denied using any medications before the present symptoms began. he had no known family history of cardiovascular malformations.

On physical examination, the patient was 72 inches tall, weighed 160 pounds, and preferred to stand, occasionally spitting up saliva. He was afebrile, with a blood pressure in the right arm of 110/74 and 92/70 in the left arm, and a pulse rate of 48 per minute. The jugular venous pressure was normal, and the carotid pulses were equal bilaterally without bruits. The heart rhythm was regular without murmurs, rubs, or gallops. Normal breath sounds were present bilaterally, the abdominal examination was unremarkable, femoral and all other peripheral pulses were normal and no cyanosis or peripheral edema were noted. A transthoracic echocardiogram was normal and the electrocardiogram was unremarkable aside from late QRS transition in the precordial leads. A barium swallow was performed and demonstrated "posterior" indentation at the level of the mid esophagus.(Insert, right)

The patient returned to the clinic after the barium swallow, now complaining of an increasing tugging sensation at the base of his tongue with associated shortness of breath.

He was referred to a cardiothoracic surgeon and a spiral CT scan was obtained that day. This revealed the presence of a right-sided aortic arch with an aberrant left subclavian artery, but without significant compromise of the tracheal lumen.(Insert, left)

To further define the anatomy, an arteriogram of the aortic arch was performed, confirming the presence of a right aortic arch with an aberrant subclavian artery.(Insert, below)

The vascular anomaly present was ascertained to be the cause of the patient's symptoms and surgical treatment was recommended. The patient underwent a thoracotomy with resection of the ligament arteriosum and release of the vascular ring. The anatomy visualized at the time of surgery confirmed the presence of a vascular ring with the right sided aortic arch. The right and left carotid arteries and the right subclavian artery arose from the ascending thoracic aorta with the left subclavian artery originating from the arch on the left side of the spine just at the beginning of the descending aorta. Postoperatively the patient complained of laryngitis for several months. At follow-up one an a half years later, the patient was asymptomatic, engaging in normal activities, and without complaints of dysphagia or laryngitis.

Discussion

The complex embryology of the aortic arch system explains the wide variety of developmental anomalies that may occur in this region. Discussions of this subject have been presented elsewhere.(1,2) Likewise, surgical approaches to these anomalies, beginning in 1965 with a report by Gross of a repair of a vascular ring,(4) have been reviewed in previous publications.(1,2,5-7)

Diagnostically, a routine chest x-ray may suggest the presence of an aortic arch anomaly, by demonstrating a widened mediastinal silhouette and/or deviation of the aortic prominence to the right. Further evaluation with a barium esophagram may reveal an extrinsic indentation of the posterior wall of the esophagus which is caused by an aberrant vessel deforming this region. Computed tomographic studies (CT scan) and magnetic resonance imaging (MRI) can provide valuable information regarding the location of the ascending thoracic aorta and the great vessels. In the case presented, the CT scan confirmed the presence of a right sided aortic arch and the aberrant left subclavian artery. Additional clarification of the anomaly type and its anatomy if generally obtained by performing an aortogram of the arch. In this way, the origin of each of the aortic arch branches can be defined in preparation for surgical intervention.

Because a symptomatic vascular ring presenting in an adult is unusual, this diagnosis is often not entertained when a patient complains of dysphagia. It is and interesting and puzzling question as to why the patient becomes symptomatic for the first time as an adult when the anomaly has been present since birth and throughout childhood, as in the present case. Reasons offered to account for this late appearance of symptoms include possible age-related elongation and dilatation of the arterial system or possible changes in esophageal motility, with the result that there may be some obstruction and constriction when there was none before.(5)

In the patient discussed in this report, it can be speculated that the trauma of a recent automobile accident with a resultant injury to the chest and associated pericarditis caused the previously asymptomatic anomaly to become symptomatic.

References

1. Leonardi HK, Naggar CZ, Ellis H. Dysphagia due to aortic arch anomaly. Arch Surg 1980;115:1229-1232.
2. Adkins RB, Maples MD, Graham BS, et al. Dysphagia associated with an aortic arch anomaly in adults. American Surgeon 1986;52:238-245.
3. Fadel E, Chapelelier AR, et al. Vascular ring causing symptomatic tracheal compression in adulthood. Ann Thorac Surg 1995;60:1411-1413.
4. Gross RE. Surgical relief for tracheal obstruction from vascular ring. N Eng J Med 1945;233:586-590.
5. Hall RJ, Treasure T. An unusual cause of dysphagia: a vascular ring. Postgrad Med J 1994;70:648-650.
6. Bertolini A, Pelizza. J Cardiovasc Surg 1987;28:301-312.
7. Chun K, Colombani PM, Dudgeon DL, Haller JA. Diagnosis and management of congenital vascular rings: a 22 year experience. Ann Thorac Surg 1992;53:597-603.
8. Baron RL, Gutierraz FR, McKnight RC. Computed tomographic evaluation of the great arteries and aortic arch malformations. In Friedman, WF and Higgins CB (eds). Pediatric Cardiac Imaging. Philadelphia, WB Saunders Company 1983; p 135.
9. Biancaniello TM, Heneghan MA. Cardiac imaging with nuclear magnetic resonance: technical considerations and potential clinical application. In Friedman, WF and Higgins CB (eds). Pediatric Cardiac Imaging. Philadelphia, WB Saunders Company 1983; p 270.