Aberrant Right Subclavian Artery Aneurysm

Transcription

1 Aberrant Right Subclavian Artery William S. Stoney, M.D., William C. Alford, Jr., M.D., George R. Burrus, M.D., and Clarence S. Thomas, Jr., M.D. ABSTRACT Ten patients with aneurysm of an aberrant right subclavian artery have been previously reported. Dysphagia is not commonly part of the initial symptomatology, and the diagnosis is usually established by chest roentgenogram, esophagogram, and aortography. If operative intervention is planned, adequate preparation for bypass and thoracic aortic grafting should be made since the aneurysm may also involve the descending thoracic aorta at the site of origin of the aberrant subclavian artery. Since both ischemia of the involved arm and the subclavian steal syndrome may occur after division of the origin of the subclavian artery, restoration of arterial flow in the distal subclavian artery is preferred. An additional patient is reported in whom right subclavian-to-carotid artery anastomosis was used after the subclavian artery aneurysm was removed. T he concept that dysphagia results from an aberrant right subclavian artery was first reported by David Bayford [2] in During the postmortem examination of a 62-year-old woman who had died after twenty years of unrelenting dysphagia, he found that an aberrant right subclavian artery had caused compression of the esophagus. Figure 1, a detailed drawing from this report, shows the aberrant subclavian artery crossing the mediastinum anterior to the esophagus rather than at the more common posterior location. He used the term dysphagia lusus naturae, meaning dysphagia from a game or freak of nature, to describe this anomaly; dysphagia lworia, the term commonly used today, is derived from this report. In 1946 Robert Gross [8] reported surgical division of an aberrant subclavian artery in an infant with dysphagia. Subsequent reports have shown that this is the most common anomaly of the aortic arch and that it usually does not cause symptoms. However, a small percentage of infants do have partial esophageal obstruction relieved by operative division of the anomalous artery. Less commonly, symptoms may suddenly appear later in life, as in Bayford s original report El. Ten patients with an aneurysm of an aberrant subclavian artery have been reported over the past seventeen years. Our recent experience with a patient having such an aneurysm stimulated a review of these previous reports, looking with particular interest at the problem of reconstruction of the subclavian artery. A 63-year-old man was hospitalized because of dyspnea on exertion. A chest roentgenogram revealed mild pulmonary fibrosis and a large mass in the superior From the Cardiac Surgical Service, St. Thomas Hospital, Nashville, Tenn. Accepted for publication Sept. 18, Address reprint requests to Dr. Stoney, 2108 West End Ave., Nashville, Tenn THE ANNALS OF THORACIC SURGERY

2 CASE REPORT: Right Subclavian FIG. 1. Reproduction of Plate 4 of Bayford s article [2]publkhed in The aberrant subclavian arte7y crosses the mediastinurn between the esophagus and trachea. (Courtesy National Library of Medicine.) VOL. 19, NO. 4, APRIL,

3 STONEY ET AL. FIG. 2. Preoperative chest roentgenogram shows a large muss in the superior mediastinum extending to the right. mediastinum extending to the right (Fig. 2). Dysphagia was reported on direct questioning but was not a prominent symptom. An aneurysm was suspected, and an arch aortogram confirmed the presence of an aberrant right subclavian artery aneurysm originating as the fourth arch vessel. The first arch vessel was the right carotid artery, the second the left carotid artery, and the third the left subclavian artery. A large Kommerell diverticulum was noted opposite the origin of the aberrant subclavian artery (Fig. 3). A roentgenogram of the esophagus showed a very large posterior filling defect conforming to the retroesophageal aneurysm (Fig. 4). Operative repair was advised (Fig. 5). The origin of the aneurysm was exposed through a left posterolateral thoracotomy incision. After adequate dissection, partially occluding clamps were placed across the aortic origin of the aneurysm to allow division of the aorta and the aneurysm (Fig. 5B). The aorta was repaired using Teflon-felt-buttressed FIG. 3. Angiogram shows aneurysm of aberrant right subclavian artery opposite a large Kommerell diverticulum. 462 THE ANNALS OF THORACIC SURGERY

4 CASE REPORT: Right Subclavian FIG. 4. Chest roentgenogram shows anterior displacement of upper esophagw by the aberrant subclavian artery aneurysm. sutures. The aneurysm was closed in a similar fashion and then mobilized as far as possible across the mediastinum to the right thoracic outlet. After the thoracotomy wound was closed and the patient was turned to a supine position, a right supraclavicular incision was made, exposing the distal right subclavian A FIG. 5. (A) Operative findings. (B) Division of aorta and aneurysm. (C) Reconstruction of right subclavian artery by anastomosis to the right carotid artery. VOL. 19. NO. 4, APRIL,

5 STONEY ET AL. FIG. 6. Postoperative arteriogram shows patent subclavian artery-to-carotid artery anastomosis. and the right carotid arteries. The aneurysm was delivered into the neck incision and divided from the distal subclavian artery. Division of the right vertebral and mammary arteries was necessary to obtain enough mobility to allow anastomosis of the distal right subclavian artery to the side of the right carotid artery (Fig. 5C). Ten minutes of right carotid occlusion without shunting was needed for this anastomosis. In the postoperative period the patient required tracheostomy and respirator assistance for several days. He recovered without other problems, however, and a repeat aortogram showed satisfactory flow to the right subclavian artery (Fig. 6). He has been able to return to work, although he still has some dyspnea on exertion. He has no dysphagia at present, and a repeat esophageal study shows no abnormality. Comment A review of the 10 previously reported patients plus our own provides considerable information on this problem (Table). A superior mediastinal mass noted on chest roentgenogram was the usual finding which led to subsequent investigation and diagnosis. Surprisingly, dysphagia was the major complaint in only 1 patient, although dysphagia was present in 4 of the individuals reviewed and in our patient. Esophagogram and aortography correctly identified the problem in 9 of the 11 patients; in the remaining 2 it was identified at thoracotomy. Although none of these aneurysms ruptured, 1 patient was noted to have acute chest pain, dysphagia, and ecchymosis of the right side of the neck suggestive of leakage from the aneurysm [ 151. Nine of the 1 1 patients were treated by excision of the aneurysm; 2 died in the immediate postoperative period. Of the 2 patients who did not have aneurysmectomy, 1 had exploratory thoracotomy only and died two years later of a ruptured abdominal aneurysm. The second patient was advised not to undergo aneurysmectomy because of his age and a 464 THE ANNALS OF THORACIC SURGERY

6 PREVIOUSLY REPORTED PATIENTS WITH ABERRANT RIGHT SUBCLAVIAN ARTERY ANEURYSM ~~~~~~ ~ Reporting Patient Abdom- Subclavian Physician Age inal Dys- Recon- & Date (yr) phagia Operation Result struction Remarks s r c rd McCallen, 1956 Gomes, 1968 Hunter, 1970 Campbell, Engelman, Sarot, % Sakurai, 1973?E1 I- w Total W -l CVA = cerebrovascular accident. 3 4 Exploratory ne 9 Died Died ne ne ne ne ne Dacron graft to subclavian artery ne... ne ne Died 2 yr later of ruptured abdominal aneurysm First aberrant subclavian aneurysm Died immediately postop. Right thoracotomy incision used CVA postop. with subsequent death Alive 2 yr later Ischemia of right arm postop. Coarctation

7 STONEY ET AL. previous cerebrovascular accident. He died of a cerebrovascular accident two years later.* When an operation for aberrant subclavian artery aneurysm is being planned, it should be realized that some form of temporary bypass may be necessary. Four of the patients previously reported required either a temporary bypass or cardiopulmonary bypass during replacement of a segment of the descending aorta at the site of origin of the aberrant subclavian artery. In our patient, the left femoral artery was exposed in anticipation of using bypass to control the origin of the aneurysm; satisfactory control was obtained by partial aortic clamping, however. Division of an aberrant subclavian artery is the usual procedure chosen for children with symptoms requiring operative intervention. Postoperative ischemia of the arm has been reported in children following subclavian artery division but is quite rare. This postoperative anatomical arrangement theoretically could produce a subclavian steal syndrome, however. Folger and Shah [6] reviewed 11 1 angiocardiograms of patients who had previously undergone a Blalock-Taussig anastomosis with division of the subclavian artery. They found 12 patients with angiographic evidence of subclavian steal, and 7 had symptoms consistent with basilar artery insufficiency. In an adult, division of the subclavian artery may produce ischemia of the involved arm with the additional possibility that subclavian steal may develop later. Of the patients reviewed here, 1 had symptoms of ischemia of the right arm following excision of the subclavian aneurysm without arterial reconstruction [ 153. Several methods of restoring arterial flow to the divided aberrant subclavian artery have been reported. In 1965 Bailey and his co-workers [ 11 reported division of an aberrant right subclavian artery at its origin, anastomosing the distal artery to the ascending aorta proximal to the right carotid artery. Similarly, PifarrC and co-workers [ 131 reported 2 patients in whom the distal aberrant subclavian artery was anastomosed to the ascending aorta using a short Dacron graft. Siderys [161 reestablished arterial flow to the divided subclavian artery by anastomosing the distal subclavian artery to the side of the right carotid artery, using a separate incision in the neck. Hallman and Cooley [9] in 1964 reported a similar method: the distal aberrant subclavian artery was anastomosed to the side of the carotid within the thoracic cavity. Edwards and Wright [4] and Orvald and colleagues [ 121 have reported the use of cervical anastomosis in the treatment of subclavian artery occlusion secondary to arteriosclerotic occlusive disease; this seems to be the simplest and most effective method of establishing arterial flow to the distal subclavian artery. Our patient s aneurysm was confined to the portion of the artery derived from the eighth segment of the right dorsal aortic root, which otherwise undergoes regression at an early stage of embryological development. Although there is no supportive evidence, it is possible that this segment lacks some intrinsic structural factor which makes aneurysm development possible. Another explanation for the development of an aneurysm at this site is the remarkable hemodynamic *R. M. Engelman, personal communication, THE ANNALS OF THORACIC SURGERY

8 CASE REPORT: Right Subclavian stress involved in the tortuous course of this artery over a very short distance. The coexistence of an abdominal aneurysm in 3 of the 11 patients would indicate that arteriosclerotic changes most likely account for the development of these unusual aneurysms. References 1. Bailey, C. P., Hirose, T., and Alba, J. Re-establishment of the continuity of the anomalous right subclavian artery after operation for dysphagia lusoria. Angiology 16:509, Bayford, D. An account of a singular case of obstructed deglutition. Mem Med Soc London 2:274, Campbell, C. F. Repair of an aneurysm of an aberrant retroesophageal right subclavian artery arising from Kommerell's diverticu1um.j Thorac Cardiovasc Surg 62:330, Edwards, W. H., and Wright, R. S. Current concepts in the management of arteriosclerotic lesions of the subclavian and vertebral arteries. Ann Surg 175:975, Engelman, R. M., and Madayag, M. Aberrant right subclavian aneurysm: A rare cause of a superior mediastinal tumor. Chest 62:45, Folger, G. M., and Shah, K. D. Subclavian steal in patients with Blalock-Taussig anastomosis. Circulation 31:241, Gomes, M. M. R., Bernatz, P. E., and Forth, R. J. Arteriosclerotic aneurysm of an aberrant right subclavian artery. Dis Chest 54:63, Gross, R. E. Surgical treatment for dysphagia lusoria. Ann Surg 124:532, Hallman, G. L., and Cooley, D. A. Congenital aortic vascular ring: Surgical considerations. Arch Surg 88:666, Hunter, J. A., Dye, W. S., Javid, H., Najafi, H., and Julian, 0. C. Arteriosclerotic aneurysm of anomalous right subclavian artery. J Thorac Cardiovasc Surg 59: 754, McCallen, A. M., and Schaff, B. of an anomalous right subclavian artery. Radiology 66:561, Orvald, T. O., Schurer, R., and Jude, J. R. A single cervical approach to aberrant right subclavian artery. Surgery 71:227, PifarrC, R., Dieter, R. A., and Niedballa, R. G. Definitive surgical treatment of the aberrant retroesophageal right subclavian artery in the adult. J horac Cardiovasc Surg 61: Sakurai, H., Lukban, S., and Litwak, R. S. Coarctation of aorta associated with anomalous right subclavian artery and its aneurysm. NY State J Med 73:290, Sarot, I. A. In discussion of R. M. Engelman, M. Madayag, a;nd F. C. Spencer, of aberrant right subclavian artery. NY State J Med 73:290, Siderys, H. A. New operation for symptomatic aberrant right subclavian artery in the adult (dysphagia lusoria). J Thorac Cardiovasc Surg 57:269, VOL. 19, NO. 4, APRIL,