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Surgical treatment for aneurysm of aberrant subclavian artery based on a case report and a review of the literature
J
THoRAc CARDIOVASC SURG
1988;95:888-91
Surgical treatment for aneurysm of aberrant subclavian artery based on a case report and a review of the literature Experiences with the recent successful treatment of a patient with an aneurysm arising from an aberrant subclavian artery are described. The reported experiences with surgical treatment by others were reviewed in detail: Only 16 such patients were found, with a surprising frequency of serious complications. These data led to the conclusion that a two-stage approach, through right cervical and left thoracotomy incisions, seems to offer the ideal method of treatment for this unusual problem.
Rick A. Esposito, MD, Ismail Khalil, MD, Aubrey C. Galloway, MD, and Frank C. Spencer, MD, New York, N. Y.
Only 26 cases of an aneurysm ansmg from an aberrant subclavian artery were found in a review of reports in the English literature. This is somewhat surprising, because aberrant origin of the subclavian artery is the most common congenital anomaly of the aortic arch, found at postmortem examination in about one in 200 patients, a frequency of 0.5%.1 Clearly, the majority of patients remain symptom free. The anomaly is a familiar one because dysphagia (dysphagia lusoria) develops in some infants or young children from the retroesophageal course of the aberrant artery. Recognition and treatment of the condition by ligation of the aberrant artery was defined by Gross? in 1946. The clinical features of the 26 reported cases are characteristic of atherosclerotic aneurysms with their occurrence in an older age group and with the familiar hazards of distal embolization or rupture. As with atherosclerotic aneurysms elsewhere, the frequency of these serious complications indicates that aberrant subclavian aneurysms should be promptly excised. Only 16 patients have been operated on, with a surprisingly high frequency of serious complications: hemorrhage, distal embolization, or ischemia of the
From the Department of Surgery. New York University Medical Center. New York. N.Y. Received for publication March 18, 1987. Accepted for publication April 15. 1987. Address for reprints: R. A. Esposito. MD. 530 First Avc., Suite 60. New York. NY 10016.
888
Fig. 1. Chest roentgenogram showing mediastinal mass (ar-
row).
upper extremity. The wide variety of operative approaches used, and the frequency of potentially preventable complications, indicate that simple lack of familiarity with the condition is probably responsible for the high frequency of complications after excision. For these reasons, recent experiences with one patient
Volume 95 Number 5 May 1988
Aneurysm of aberrant subclavian artery
889
have been described in detail with the theoretical basis for a combined approach that should avoid the complications described in other reports.
Case report An asymptomatic mediastinal mass was detected on routine chest roentgenogram in a 64-year-old male patient (Fig. I). Evaluation with a computed axial tomographic scan, followed by intra-arterial subtraction angiography, showed that the mass was an aneurysm of an aberrant subclavian artery (Fig. 2) Dyspnea on exertion was the only symptom, and this was apparently a result of severe chronic emphysema (forced expiratory volume in I second 0.99 L; forced vital capacity 2.09 L). There was no dysphagia. There was a history of three previous myocardial infarctions. Coronary angiography was performed preoperatively; disease was found only in the right coronary artery, which was not considered a contraindication to operation. After review of published reports by others with a description of the different approaches used and the complications encountered, a decision was made to perform a two-stage operation. Initially, a right cervical incision was made along the anterior border of the right sternocleidomastoid muscle and extended laterally along the superior aspect of the right clavicle. Exposure of the subclavian artery proximally was limited; hence, a subperiosteal resection of the medial two thirds of the clavicle was done, which permitted division of the subclavian artery proximal to the origin of the vertebral artery. The common carotid artery was then briefly clamped and a 6 mm polytetrafluoroethylene graft* interposed between the common carotid artery and the subclavian artery. After closure of the cervical incision, the patient was turned to a lateral position, and a left posterolateral thoracotomy was done in the fourth intercostal space. The angiogram had shown dilatation and calcification of the aberrant subclavian artery near its origin from the aorta, which indicated that temporary clamping of the aorta might be necessary. Hence, a pump oxygenator was kept in the operating room in the event that cardiopulmonary bypass was necessary. The left subclavian artery was readily identified and encircled, and the origin of the aberrant right subclavian artery was then identified immediately inferiorly, slightly to the left of the normal origin of the left subclavian. The subclavian aneurysm was about 3 cm in diameter at the aortic origin with some palpable calcification in the wall. Because hazards of clamping this dilated atherosclerotic artery were clear, the ligamentum arteriosum was divided and the aortic arch encircled with ligatures proximal and distal to the aberrant subclavian, to permit clamping of the aorta if hemorrhage occurred. The aberrant subclavian artery was then clamped at the origin and the friable artery gradually transected; the cut edges were oversewn with 4-0 Tevdek (Deknatel Division, Pfizer, Inc., Floral Park, N.Y.) pledget-supported sutures. Once the artery was completely divided, the cut edge was oversewn with Prolene sutures and the clamp removed. The
*Gore-Tex vascular graft. registered tradename of W. L. Gore & Associates, lnc., Elkton. Md.
Fig. 2. Intra-arterial subtraction angiogram showing aneurysm (bottom arrow) of aberrant subclavian artery. aneurysmal sac was then opened wide and a large amount of laminated thrombus removed. The inner lining of the aneurysm was then removed and the remaining portion of the sac left in situ. The thoracotomy incision was then closed with a standard method. The postoperative course was uneventful. There was a mild Horner's syndrome detectable in the right eye, which probably resulted from dissection near the stellate ganglion in the neck. The patient was discharged in good condition 12 days after operation and in the subsequent 6 months has remained well.
Review of published reports Twenty-six reported cases of aneurysm of an aberrant subclavian artery were found in a review of the English literature.' Sixteen of the patients were operated on. Five of the 10 patients not operated on died of spontaneous rupture, which indicates the gravity of the disease. The 16 patients operated on, and the patient described in this report, are listed in chronological order in Table I. These reports were analyzed in detail regarding the operative approach, the restoration of blood flow to the upper extremity, and the occurrence of embolization. Operative approach. A left thoracotomy was used in nine patients,':" and a right thoracotomy in five.3.11-14 No operative deaths occurred in these two groups. A median sternotomy was used in two patients 6 . 15 because of incorrect preoperative diagnosis. Both patients died in the recovery room, one of exsanguinating hemorrhage" and the other of unstated causes." One patient was treated with cardiopulmonary bypass, but the operative incision was not described. This patient died subsequently of an intraoperative stroke." Vascular reconstruction. Among the 14 patients
The Journal of
8 90
Thoracic and Cardiovascular Surgery
Esposito et al.
Table I. Reported cases of surgically treated aneurysm of an aberrant subclavian artery Primary author/Year
Age/Sex
Operative approach
Subclavian bypass
Survival
Complications Infected suture line Loss of radial pulse Exsanguinated in recovery room Cause of death not stated None None None Perioperative cerebrovascular accident Cerebral embolus. ischemic hand Chronically ischemic hands Prolonged ventilator support None Loss of radial pulse Cerebral emboli None Brachial artery embolus Horner's on right side
Shannon/1961 Gomes/1968 Lynn/1969
62/F 60/M 57/M
Left thoracotomy Left thoracotomy Median sternotomy
None None None
Yes Yes No
Hunter/1970
71/M
Median sternotomy
None
No
Campbell/1971 Engelman/1972
55/M 71/M 69/M 74/M
Left thoracotomy Left thoracotomy Right thoracotomy Not described
None None Dacron fabric graft None
Yes Yes Yes No
Sarot/1973
63/M
Right thoracotomy
None
Yes
Sakurai/1973
40/F
Left thoracotomy
None
Yes
Stoney/1975
63/M
Subclavian-carotid
Yes
Rodgers ' l 978 Mclntyre/1980 Schmidt/1980 Esquivel/1984 Austin/1985
11/F 64/M 67/M 74/M 67/F
Left thoracotomy. right supraclavicular Right thoracotomy Right thoracotomy Left thoracotomy Left thoracotomy Right thoracotomy
None None None Axillo-axillary Dacron fabric graft
Yes Yes Yes Yes Yes
Present study /1987
64/M
Left thoracotomy, right supraclavicular
Subclavian-carotid
Yes
who survived operation, only five had blood flow restored to the right arm at the time of operation. Among these five, a carotid-subclavian bypass was used in two," a synthetic graft originating from the aorta in two/ II and an axillo-axillary bypass in one.'? The frequency of significant ischemic complications in the nine patients treated simply by ligation of the subclavian artery was notable; severe limb ischemia developed in two of these patients, One patient had coldness, numbness, and early claudication in both arms after the ligation of both subclavian arteries.' In a second patient, progressive limb ischemia resulted in rest pain and, ultimately, fingertip necrosis." The remaining seven patients were reported to remain free of symptoms on limited follow-up, although two patients were noted to have loss of the radial pulse in the affected extremity.5.14 Long-term data concerning the presence of ischemia in the right arm were not reported. Intraoperative embolization. It was impressive that intraoperative emboli developed in three of the 14 patients, surely from thrombi dislodged from the aneurysmal sac, Two had cerebral vascular symptoms; blurred vision in one patient" and cortical blindness, agraphia, and astereognosis in another." In the third patient the right upper extremity became cold and
pulseless; the limb was salvaged with immediate brachial artery embolectomy.' Discussion
Clearly, the available data indicate that excision should be done soon after the diagnosis is made unless other diseases indicate a serious operative risk, The fact that five of the 10 patients treated without operation subsequently died of rupture establishes the gravity of the problem. A two-stage operative approach. The wide variety of techniques used, combined with the significant frequency of complications from operative hemorrhage, intraoperative embolization, and ischemia of the arm, clearly indicate the potential hazards with the operation. Treatment of the aneurysm should be simple and effective, because anatomically it is far less complex than aneurysms such as those involving the aortic arch or the thoracoabdominal aorta. Hence, the alarming frequency of complications found in previous reports surely represents a lack of familiarity with the condition because of its rarity. The two-stage operative technique used in the patient described in this report would seem to prevent the three major hazards of operative hemorrhage, operative
Volume 95 Number 5 May 1988
embolization, and ischemia of the right arm. The initial approach through a right cervical incision permits division of the subclavian artery before the aneurysmal sac is manipulated, after which reconstruction can easily be done by connecting the subclavian artery to the right carotid artery. The necessity of reestablishing blood flow to the arm after the subclavian artery is divided merits detailed consideration, because the majority of patients undergoing aneurysm resection did not have a concomitant arterial bypass. The apparent unwarranted optimism about limb viability after subclavian artery ligation is probably based on extrapolation of clinical experiences in infants and neonates, in whom subclavian artery ligation is routinely done during the construction of systemic-to-pulmonary shunts (Blalock-Taussig) with a very low incidence of limb ischemia. However, the reported incidence of limb gangrene after subclavian artery ligation for trauma is a striking 29%,17 similar to the incidence of limb ischemia (22%) in those patients undergoing aneurysm resection without arterial bypass. Once the proximal subclavian artery has been ligated and the vascular supply to the upper extremity restored, a left thoracotomy can be done, which permits the best exposure of the origin of the aneurysm from the aorta. Almost surely, in some patients with extensive atherosclerosis of the origin of the aneurysm, temporary clamping of the aorta wil1 be necessary. With proper exposure, however, this should not cause significant morbidity. Keeping a heart-lung machine on a standby basis would permit the prompt use of partial bypass if necessary, as is usual1y done with the more common aneurysms of the thoracic aorta. Conclusions
1. An aneurysm ansmg in an aberrant subclavian artery should be operated on promptly, because reports by others show that five of 10 patients not operated on died of complications of the aneurysm. 2. The operative procedure should include excision of the aneurysm and restoration of blood flow to the right arm. The most serious operative hazards are hemorrhage and embolization. These facts suggest that the best approach is a two-stage one, with first a right cervical incision and then a left thoracotomy incision. 3. The elective use of an operative approach through two separate incisions has not been emphasized in reports by others, probably because of the rarity of the
Aneurysm of aberrant subclavian artery
89 1
condition and lack of recognition of the serious operative complications that have been reported. REFERENCES I. Stewart lR, Kincaid OW, Edwards lE. An atlas of vascular rings and related malformations of the aortic arch system. Springfield, Illinois: Charles C Thomas, Publisher, 1964. 2. Gross RE. Surgical treatment of dysphagia lusoria. Ann Surg 1946; 124:532-4. 3. Austin EH, Wolfe WG. Aneurysm of aberrant subclavian artery with a review of the literature. 1 Vase Surg 1985;2:571-7. 4. Shannon 1M. Aberrant right subclavian artery with Kornmerell's diverticulum: report of a case. 1 THoRAc CARDIOVASC SURG 1961;41:408-11. 5. Gomes MMR, Bernatz PE, Forth Rl. Arteriosclerotic aneurysm of the aberrant subclavian artery. Dis Chest 1968;54:549-52. 6. Hunter lA, Dye WS, lavid H, Najafi H, lulian Oe. Arteriosclerotic aneurysm of anomalous right subclavian artery. 1 THoRAc CARDIOVASC SURG 1970;59:754-8. 7. Sakurai H, Lukban S, Litwak RS. Coarctation of aorta associated with anomalous right subclavian artery and its aneurysm. NY State 1 Med 1973;73:292-6. 8. Stoney WS, Alford WC, Burrus GR, Thomas CS. Aberrant right subclavian artery aneurysm. Ann Thorac Surg 1975; 19:460-7. 9. Schmidt FE, Hewitt RL, Flores AA. Aneurysm of anomalous right subclavian artery. South Med 1 1980;73:255-6. 10. Esquivel C, Miller GC lr. Aneurysm of anomalous right subclavian artery. Contemp Surg 1984;24:81. 11. Campbell CF. Repair of an aneurysm of aberrant retroesophageal right subclavian artery arising from Kommerell's diverticulum. 1 THoRAc CARDIOVASC SURG 1971; 62:330-4. 12. Sarot lA. Discussion of Engelman RM, Madayag M, Spencer Fe. Aneurysm of right subclavian artery. NY State 1 Med 1973;73:290-2. 13. Rodgers BM, Tabert Jl., Hollenbeck lL. Aneurysm of anomalous subclavian artery: an unusual case of dysphagia lusoria in childhood. Ann Surg 1978; 187:158-60. 14. McIntyre MD, Lynn RB. Kommerells diverticulum. Can 1 Surg 1980;23:356. 15. Lynn RB. Kornmerell's diverticulum with esophagoarterial fistula. Can 1 Surg 1969;12:331-3. 16. Engelman RM, Madayag M. Aberrant right subclavian artery aneurysm: a rare case of superior mediastinal tumor. Chest 1972;62:45-7. 17. Rich NM, Spencer Fe. Vascular trauma. Philadelphia: WB Saunders Company, 1978.
THoRAc CARDIOVASC SURG
1988;95:888-91
Surgical treatment for aneurysm of aberrant subclavian artery based on a case report and a review of the literature Experiences with the recent successful treatment of a patient with an aneurysm arising from an aberrant subclavian artery are described. The reported experiences with surgical treatment by others were reviewed in detail: Only 16 such patients were found, with a surprising frequency of serious complications. These data led to the conclusion that a two-stage approach, through right cervical and left thoracotomy incisions, seems to offer the ideal method of treatment for this unusual problem.
Rick A. Esposito, MD, Ismail Khalil, MD, Aubrey C. Galloway, MD, and Frank C. Spencer, MD, New York, N. Y.
Only 26 cases of an aneurysm ansmg from an aberrant subclavian artery were found in a review of reports in the English literature. This is somewhat surprising, because aberrant origin of the subclavian artery is the most common congenital anomaly of the aortic arch, found at postmortem examination in about one in 200 patients, a frequency of 0.5%.1 Clearly, the majority of patients remain symptom free. The anomaly is a familiar one because dysphagia (dysphagia lusoria) develops in some infants or young children from the retroesophageal course of the aberrant artery. Recognition and treatment of the condition by ligation of the aberrant artery was defined by Gross? in 1946. The clinical features of the 26 reported cases are characteristic of atherosclerotic aneurysms with their occurrence in an older age group and with the familiar hazards of distal embolization or rupture. As with atherosclerotic aneurysms elsewhere, the frequency of these serious complications indicates that aberrant subclavian aneurysms should be promptly excised. Only 16 patients have been operated on, with a surprisingly high frequency of serious complications: hemorrhage, distal embolization, or ischemia of the
From the Department of Surgery. New York University Medical Center. New York. N.Y. Received for publication March 18, 1987. Accepted for publication April 15. 1987. Address for reprints: R. A. Esposito. MD. 530 First Avc., Suite 60. New York. NY 10016.
888
Fig. 1. Chest roentgenogram showing mediastinal mass (ar-
row).
upper extremity. The wide variety of operative approaches used, and the frequency of potentially preventable complications, indicate that simple lack of familiarity with the condition is probably responsible for the high frequency of complications after excision. For these reasons, recent experiences with one patient
Volume 95 Number 5 May 1988
Aneurysm of aberrant subclavian artery
889
have been described in detail with the theoretical basis for a combined approach that should avoid the complications described in other reports.
Case report An asymptomatic mediastinal mass was detected on routine chest roentgenogram in a 64-year-old male patient (Fig. I). Evaluation with a computed axial tomographic scan, followed by intra-arterial subtraction angiography, showed that the mass was an aneurysm of an aberrant subclavian artery (Fig. 2) Dyspnea on exertion was the only symptom, and this was apparently a result of severe chronic emphysema (forced expiratory volume in I second 0.99 L; forced vital capacity 2.09 L). There was no dysphagia. There was a history of three previous myocardial infarctions. Coronary angiography was performed preoperatively; disease was found only in the right coronary artery, which was not considered a contraindication to operation. After review of published reports by others with a description of the different approaches used and the complications encountered, a decision was made to perform a two-stage operation. Initially, a right cervical incision was made along the anterior border of the right sternocleidomastoid muscle and extended laterally along the superior aspect of the right clavicle. Exposure of the subclavian artery proximally was limited; hence, a subperiosteal resection of the medial two thirds of the clavicle was done, which permitted division of the subclavian artery proximal to the origin of the vertebral artery. The common carotid artery was then briefly clamped and a 6 mm polytetrafluoroethylene graft* interposed between the common carotid artery and the subclavian artery. After closure of the cervical incision, the patient was turned to a lateral position, and a left posterolateral thoracotomy was done in the fourth intercostal space. The angiogram had shown dilatation and calcification of the aberrant subclavian artery near its origin from the aorta, which indicated that temporary clamping of the aorta might be necessary. Hence, a pump oxygenator was kept in the operating room in the event that cardiopulmonary bypass was necessary. The left subclavian artery was readily identified and encircled, and the origin of the aberrant right subclavian artery was then identified immediately inferiorly, slightly to the left of the normal origin of the left subclavian. The subclavian aneurysm was about 3 cm in diameter at the aortic origin with some palpable calcification in the wall. Because hazards of clamping this dilated atherosclerotic artery were clear, the ligamentum arteriosum was divided and the aortic arch encircled with ligatures proximal and distal to the aberrant subclavian, to permit clamping of the aorta if hemorrhage occurred. The aberrant subclavian artery was then clamped at the origin and the friable artery gradually transected; the cut edges were oversewn with 4-0 Tevdek (Deknatel Division, Pfizer, Inc., Floral Park, N.Y.) pledget-supported sutures. Once the artery was completely divided, the cut edge was oversewn with Prolene sutures and the clamp removed. The
*Gore-Tex vascular graft. registered tradename of W. L. Gore & Associates, lnc., Elkton. Md.
Fig. 2. Intra-arterial subtraction angiogram showing aneurysm (bottom arrow) of aberrant subclavian artery. aneurysmal sac was then opened wide and a large amount of laminated thrombus removed. The inner lining of the aneurysm was then removed and the remaining portion of the sac left in situ. The thoracotomy incision was then closed with a standard method. The postoperative course was uneventful. There was a mild Horner's syndrome detectable in the right eye, which probably resulted from dissection near the stellate ganglion in the neck. The patient was discharged in good condition 12 days after operation and in the subsequent 6 months has remained well.
Review of published reports Twenty-six reported cases of aneurysm of an aberrant subclavian artery were found in a review of the English literature.' Sixteen of the patients were operated on. Five of the 10 patients not operated on died of spontaneous rupture, which indicates the gravity of the disease. The 16 patients operated on, and the patient described in this report, are listed in chronological order in Table I. These reports were analyzed in detail regarding the operative approach, the restoration of blood flow to the upper extremity, and the occurrence of embolization. Operative approach. A left thoracotomy was used in nine patients,':" and a right thoracotomy in five.3.11-14 No operative deaths occurred in these two groups. A median sternotomy was used in two patients 6 . 15 because of incorrect preoperative diagnosis. Both patients died in the recovery room, one of exsanguinating hemorrhage" and the other of unstated causes." One patient was treated with cardiopulmonary bypass, but the operative incision was not described. This patient died subsequently of an intraoperative stroke." Vascular reconstruction. Among the 14 patients
The Journal of
8 90
Thoracic and Cardiovascular Surgery
Esposito et al.
Table I. Reported cases of surgically treated aneurysm of an aberrant subclavian artery Primary author/Year
Age/Sex
Operative approach
Subclavian bypass
Survival
Complications Infected suture line Loss of radial pulse Exsanguinated in recovery room Cause of death not stated None None None Perioperative cerebrovascular accident Cerebral embolus. ischemic hand Chronically ischemic hands Prolonged ventilator support None Loss of radial pulse Cerebral emboli None Brachial artery embolus Horner's on right side
Shannon/1961 Gomes/1968 Lynn/1969
62/F 60/M 57/M
Left thoracotomy Left thoracotomy Median sternotomy
None None None
Yes Yes No
Hunter/1970
71/M
Median sternotomy
None
No
Campbell/1971 Engelman/1972
55/M 71/M 69/M 74/M
Left thoracotomy Left thoracotomy Right thoracotomy Not described
None None Dacron fabric graft None
Yes Yes Yes No
Sarot/1973
63/M
Right thoracotomy
None
Yes
Sakurai/1973
40/F
Left thoracotomy
None
Yes
Stoney/1975
63/M
Subclavian-carotid
Yes
Rodgers ' l 978 Mclntyre/1980 Schmidt/1980 Esquivel/1984 Austin/1985
11/F 64/M 67/M 74/M 67/F
Left thoracotomy. right supraclavicular Right thoracotomy Right thoracotomy Left thoracotomy Left thoracotomy Right thoracotomy
None None None Axillo-axillary Dacron fabric graft
Yes Yes Yes Yes Yes
Present study /1987
64/M
Left thoracotomy, right supraclavicular
Subclavian-carotid
Yes
who survived operation, only five had blood flow restored to the right arm at the time of operation. Among these five, a carotid-subclavian bypass was used in two," a synthetic graft originating from the aorta in two/ II and an axillo-axillary bypass in one.'? The frequency of significant ischemic complications in the nine patients treated simply by ligation of the subclavian artery was notable; severe limb ischemia developed in two of these patients, One patient had coldness, numbness, and early claudication in both arms after the ligation of both subclavian arteries.' In a second patient, progressive limb ischemia resulted in rest pain and, ultimately, fingertip necrosis." The remaining seven patients were reported to remain free of symptoms on limited follow-up, although two patients were noted to have loss of the radial pulse in the affected extremity.5.14 Long-term data concerning the presence of ischemia in the right arm were not reported. Intraoperative embolization. It was impressive that intraoperative emboli developed in three of the 14 patients, surely from thrombi dislodged from the aneurysmal sac, Two had cerebral vascular symptoms; blurred vision in one patient" and cortical blindness, agraphia, and astereognosis in another." In the third patient the right upper extremity became cold and
pulseless; the limb was salvaged with immediate brachial artery embolectomy.' Discussion
Clearly, the available data indicate that excision should be done soon after the diagnosis is made unless other diseases indicate a serious operative risk, The fact that five of the 10 patients treated without operation subsequently died of rupture establishes the gravity of the problem. A two-stage operative approach. The wide variety of techniques used, combined with the significant frequency of complications from operative hemorrhage, intraoperative embolization, and ischemia of the arm, clearly indicate the potential hazards with the operation. Treatment of the aneurysm should be simple and effective, because anatomically it is far less complex than aneurysms such as those involving the aortic arch or the thoracoabdominal aorta. Hence, the alarming frequency of complications found in previous reports surely represents a lack of familiarity with the condition because of its rarity. The two-stage operative technique used in the patient described in this report would seem to prevent the three major hazards of operative hemorrhage, operative
Volume 95 Number 5 May 1988
embolization, and ischemia of the right arm. The initial approach through a right cervical incision permits division of the subclavian artery before the aneurysmal sac is manipulated, after which reconstruction can easily be done by connecting the subclavian artery to the right carotid artery. The necessity of reestablishing blood flow to the arm after the subclavian artery is divided merits detailed consideration, because the majority of patients undergoing aneurysm resection did not have a concomitant arterial bypass. The apparent unwarranted optimism about limb viability after subclavian artery ligation is probably based on extrapolation of clinical experiences in infants and neonates, in whom subclavian artery ligation is routinely done during the construction of systemic-to-pulmonary shunts (Blalock-Taussig) with a very low incidence of limb ischemia. However, the reported incidence of limb gangrene after subclavian artery ligation for trauma is a striking 29%,17 similar to the incidence of limb ischemia (22%) in those patients undergoing aneurysm resection without arterial bypass. Once the proximal subclavian artery has been ligated and the vascular supply to the upper extremity restored, a left thoracotomy can be done, which permits the best exposure of the origin of the aneurysm from the aorta. Almost surely, in some patients with extensive atherosclerosis of the origin of the aneurysm, temporary clamping of the aorta wil1 be necessary. With proper exposure, however, this should not cause significant morbidity. Keeping a heart-lung machine on a standby basis would permit the prompt use of partial bypass if necessary, as is usual1y done with the more common aneurysms of the thoracic aorta. Conclusions
1. An aneurysm ansmg in an aberrant subclavian artery should be operated on promptly, because reports by others show that five of 10 patients not operated on died of complications of the aneurysm. 2. The operative procedure should include excision of the aneurysm and restoration of blood flow to the right arm. The most serious operative hazards are hemorrhage and embolization. These facts suggest that the best approach is a two-stage one, with first a right cervical incision and then a left thoracotomy incision. 3. The elective use of an operative approach through two separate incisions has not been emphasized in reports by others, probably because of the rarity of the
Aneurysm of aberrant subclavian artery
89 1
condition and lack of recognition of the serious operative complications that have been reported. REFERENCES I. Stewart lR, Kincaid OW, Edwards lE. An atlas of vascular rings and related malformations of the aortic arch system. Springfield, Illinois: Charles C Thomas, Publisher, 1964. 2. Gross RE. Surgical treatment of dysphagia lusoria. Ann Surg 1946; 124:532-4. 3. Austin EH, Wolfe WG. Aneurysm of aberrant subclavian artery with a review of the literature. 1 Vase Surg 1985;2:571-7. 4. Shannon 1M. Aberrant right subclavian artery with Kornmerell's diverticulum: report of a case. 1 THoRAc CARDIOVASC SURG 1961;41:408-11. 5. Gomes MMR, Bernatz PE, Forth Rl. Arteriosclerotic aneurysm of the aberrant subclavian artery. Dis Chest 1968;54:549-52. 6. Hunter lA, Dye WS, lavid H, Najafi H, lulian Oe. Arteriosclerotic aneurysm of anomalous right subclavian artery. 1 THoRAc CARDIOVASC SURG 1970;59:754-8. 7. Sakurai H, Lukban S, Litwak RS. Coarctation of aorta associated with anomalous right subclavian artery and its aneurysm. NY State 1 Med 1973;73:292-6. 8. Stoney WS, Alford WC, Burrus GR, Thomas CS. Aberrant right subclavian artery aneurysm. Ann Thorac Surg 1975; 19:460-7. 9. Schmidt FE, Hewitt RL, Flores AA. Aneurysm of anomalous right subclavian artery. South Med 1 1980;73:255-6. 10. Esquivel C, Miller GC lr. Aneurysm of anomalous right subclavian artery. Contemp Surg 1984;24:81. 11. Campbell CF. Repair of an aneurysm of aberrant retroesophageal right subclavian artery arising from Kommerell's diverticulum. 1 THoRAc CARDIOVASC SURG 1971; 62:330-4. 12. Sarot lA. Discussion of Engelman RM, Madayag M, Spencer Fe. Aneurysm of right subclavian artery. NY State 1 Med 1973;73:290-2. 13. Rodgers BM, Tabert Jl., Hollenbeck lL. Aneurysm of anomalous subclavian artery: an unusual case of dysphagia lusoria in childhood. Ann Surg 1978; 187:158-60. 14. McIntyre MD, Lynn RB. Kommerells diverticulum. Can 1 Surg 1980;23:356. 15. Lynn RB. Kornmerell's diverticulum with esophagoarterial fistula. Can 1 Surg 1969;12:331-3. 16. Engelman RM, Madayag M. Aberrant right subclavian artery aneurysm: a rare case of superior mediastinal tumor. Chest 1972;62:45-7. 17. Rich NM, Spencer Fe. Vascular trauma. Philadelphia: WB Saunders Company, 1978.