A Doubtful Cause of Symptoms Thomas P. Comer, M.D., Malvin Weinberger, M.D., and Howard D. Sirak, M.D. ABSTRACT Ten patients with surgically treated aberrant right subclavian artery are reviewed. In half, the symptoms persisted postoperatively. We believe that since this anomaly occurs commonly and since respiratory and swallowing difficulties are frequent in the first few months of life, one should make an exhaustive search for other causes of these symptoms before recommending surgical intervention. A n aberrant right subclavian artery arises as the last branch of the aortic arch instead of from the innominate artery, and passes obliquely toward the right side behind the esophagus to the upper border of the first rib, where it follows its ordinary course (Fig. 1). This is a common anomaly occurring more than once in every 200 persons [l, 2, 71. In the United States there are more than one million people with the anomaly. The purpose of this paper is to dispute the commonly accepted idea that aberrant right subclavian artery frequently is a cause of symptoms. The records of patients operated upon at Columbus Children s Hospital for aberrant right subclavian artery during the past ten years form the basis of this report. Anatomy Barry [3] and Congdon [S] have reviewed the embryology of aberrant right subclavian artery extensively. It is the regression of the right fourth aortic arch rather than the right dorsal aortic segment that produces the anomaly (Fig. 2). In the literature [6, 11, 121 it is stated that the course of the anomalous right subclavian artery is behind the esophagus in 80% of patients, between the trachea and esophagus in 10 to 15%, and in front of the trachea in 5 to 10%. The source for these percentages relates back to an article by Holzapfel [lo] published in 1899. In a critical review of the references cited by Holzapfel, Beabout and associates [51 were unable to find a well-documented case in which the anomalous artery passed other than posterior to the esophagus. From the Division of Thoracic Surgery, Department of Surgery, Ohio State University College of Medicine and Children s Hospital, Columbus, Ohio. Accepted for publication Dec. 10, 1971. Address reprint requests to Dr. Comer, Kern General Hospital, 1830 Flower St., Bakersfield, Calif. 93305. VOL. 13, NO. 6, JUNE, 1972 559
COMER, WEINBERGER, AND SIRAK BERRANT RIGHT SUBCLAVIAN FIG. 1, Aberrant right subclrivim artery. In 1957 Scheldrup [ 111 reported the postmortem finding of an aberrant right subclavian artery passing between the trachea and esophagus. Other than this, there have been no reports in the recent literature of the anomalous vessel passing between the esophagus and trachea or anterior to the trachea. Material The records of infants with an aberrant right subclavian artery treated surgically during the past ten years at the Columbus Children s Hospital were reviewed (Table). In all patients the anomalous artery passed posterior to the esophagus, and all had the characteristic posterior indentation of the esophagus on barium swallow (Fig. 3). The 10 patients included 7 boys and 3 girls. Ages at the time of operation varied from 8 days to 7 months. All patients had respiratory difficulty, and 3 had associated difficulty swallowing. Of the 10, only 2 had a birth weight of less than 5 pounds, 1 being 4 pounds 14 ounces and the other, 2 pounds. All patients had division of the aberrant vessel at the aorta. The 1 postoperative death was that of a patient with Down s syndrome who could not be weaned from the respirator. Followup by interview or letter was available for 8 patients: 1 patient was lost to follow-up. At the time of follow-up, which ranged from one month to ten years with an average of two and one-half years, 3 patients were asymptomatic and 5 were still symptomatic. 560 THE ANNALS OF THORACIC SURGERY
FIG. 2. Embryology of development of aberrant right subclavian artery with regression of the right fourth aortic arch rather than the right dorsal aortic segment. Comment The diagnosis of aberrant right subclavian artery is frequently made by a history of respiratory or swallowing difficulties associated with the classic roentgenographic finding of posterior indentation in the barium-filled esophagus above the level of the aortic arch. The indentation angles upward from left to right and corresponds to the course of the vessel toward the superior aspect of the right first rib. The defect is smaller than the posterior compression of vascular rings, such as in a double aortic arch. It is important to note that the esophagus is never dilated above the aberrant right subclavian artery, even in adults, so that, at least roentgenographically, obstruction is doubtful. Frequently the aortic knob in older persons creates a greater defect in the esophagus. Should the anomalous vessel become aneurysmal, as recently reported by Gomes [9], then obstruction is more plausible. The frequency with which respiratory and swallowing difficulties that occur in the first few months of life resolve with conservative management, such as the use of a chalasia chair and psychological support, is well known. It is hard to know, though, which is more important in the patients who VOL. 13, NO. 6, JUNE, 1972 561
COMER, WEINBERGER, AND SIRAK SURGICALLY TREATED PATIENTS WITH ABERRANT RIGHT SUBCLAVIAN ARTERY Patient's Birth Symptoms at Length of Sex & Age Weight Symptoms Follow-up Follow-up M, 8 days 6 lb. 5 oz. Choking spells... a... a M, 6 wk. 7 lb. 0 oz. Pneumonia... b... b M, 7 wk. 7 lb. 8 oz. Stridor, feeding Stridor persists 2 yr. problem M, 8 wk. 5 lb. 14 oz. Wheeze Pe cough Unchanged 1 yr. M, 3 mo. 6 lb. 15 oz. Pneumonia Asymptomatic 1 yr. M, 3 mo. 6 Ib. 10 oz. Cough & re- Unchanged 2 mo. gurgitation M, 6mo. 5 lb. 13 oz. Frequent Unchanged 5 yr. pneumonias, retardation, Apgar 5 F, 6mo. 5 lb. 0 oz. Bronchitis Asymptomatic 2 yr. F, 6mo. 2 lb. 0 oz. Pneumonia Asymptomatic 10 yr. F, 7mo. 4 lb. 14 oz. Bronchitis, Unchanged 4 mo. regurgitation "Lost to follow-up. bdied postoperatively (Down's syndrome). FIG. 3. Posterior indentation of the esophagus by aberrant right subclavian artery on barium swallow. 562 THE ANNALS OF THORACIC SURGERY
become asymptomatic postoperatively-the actual division of the aberrant artery or the time and possible psychological support it offers to the parents. The fact that 5 of our 10 surgically treated patients did not have dramatic improvement following division of the supposedly obstructing vessel should make one approach surgical treatment of this anomaly with caution. We recommend an aggressive but conservative approach to relieve symptoms in patients with respiratory and swallowing difficulties and simultaneous aberrant right subclavian artery, along with a thorough search for such problems as cystic fibrosis, chalasia, hiatus hernia, neuromuscular problems of central nervous system origin, or duplications. Our 1 postoperative death was that of a patient with Down s syndrome who could not be weaned from the respirator. Postmortem examination showed nonspecific lung changes. In the original description, in 1794, of a symptomatic aberrant right subclavian artery, Bayford [4] gives a descriptive account of a patient, Jane Fordham, with a fatal history of progressive dysphagia, a history that is not at all incompatible with scleroderma. He gave the syndrome the name dysphagia Zusoria, which means difficulty in swallowing due to a trick of nature. We agree with Bayford that nature may be playing a trick on us, but we believe the trick may well be that the vast majority of aberrant right subclavian arteries truly do not cause symptoms. References 1. Abbott, M. E. Atlas of Congenital Cardiac Disease. New York: American Heart Association, 1936. Pp. 16, 17, and 61. 2. Raider, L. Aberrant right subclavian artery. South. Med. J. 60:145, 1967. 3. Barry, A. Aortic arch derivatives in human adult. Anat. Rec. 111:221, 1951. 4. Bayford, D. Account of singular case of obstructed deglutition. Mem. Med. SOC. London 2:275, 1794. 5. Beabout, J. W., Stewart, J. R., and Kincaid, 0. W. Aberrant right subclavian artery; dispute of commonly accepted concepts. Am. J. Roentgenol. Radium Ther. Nucl. Med. 92:855, 1964. 6. Blake, H. A., and Manion, W. C. Thoracic arterial arch anomalies, Circulation 26:251, 1962. 7. Carney, J. Anomalous right subclavian artery considered in light of recent findings in arterial development: With a note on two cases of an unusual relation of innominate artery to trachea. J. Anat. 59265, 1925. 8. Congdon, E. D. Transformation of aortic arch system during development of human embryo. Contrib. Embryol. 14:47, 1922. 9. Gomes, M. M., Bernatz, P. E., and Forth, R. J. Arteriosclerotic aneurysm of an aberrant right subclavian artery. Dis. Chest 54:63, 1968. 10. Holzapfel, G. Ungewohnlicher Ursprung und Verlauf der Arteria Subclavian Dextra. Tiibingen and Wiesbaden: Bergmann, 1899. P. 153. 11. Scheldrup, E. W. Vascular anomalies of retro-infrahyoid (pretracheal) space and their importance in tracheotomy. Surg. Gynecol. Obstet. 105:327, 1957. 12. Zdondsky, E. Roentgen Dingnosis of the Heart and Great Vessels (Translated by L. J. Boyd, 1st American edition). New York: Grune & Stratton, 1953. Pp. 416418. VOL. 13, NO. 6, JUNE, 1972 563