Arterial Complications of the Thoracic Outlet Syndrome Richard A. Dorazio, MD, FACS, Los Angeles, California Faik Ezzet, MD, FACS, Los Angeles, California
The thoracic outlet syndrome is a symptom complex caused by compression of neurovascular structures at the thoracic outlet [I]. Neurologic symptoms are most common and often respond to physical therapy; when operation becomes necessary, excellent results are achieved with transaxillary resection of the first rib [2]. Vascular complications of the thoracic outlet may be venous or arterial. Many cases of axillary-subclavian venous thrombosis, such as “effort thrombosis,” probably represent the end result of thoracic outlet compression of the subclavian vein [3]. The role of surgical treatment of these patients is controversial. Arterial complications of the thoracic outlet syndrome are the least common but by far the most serious. These include poststenotic dilatation, mural thrombus, total occlusion, aneurysm, or any combination thereof [4]. They require urgent diagnostic and therapeutic measures. Unfortunately, the early signs and symptoms of arterial involvement are usually unrecognized. The basic pathophysiologic mechanism consists of repeated distal embolization from a proximal lesion in the subclavian artery [5]. Consequently, most patients have some degree of irreversible change in the circulation of the arm before the diagnosis is made. Surgical treatment is readily accomplished using a supraclavicular incision with resection of the clavicle to facilitate exposure. This approach allows simultaneous vascular repair and correction of the underlying thoracic outlet compression and has no significant cosmetic or functional disadvantages. Our experience with five patients constitutes the basis of this report.
From the Department of Surgery, Kaiser Permanente Medical Center, Los Angeles, California. Reprint requests should be addressed to Richard A. Dorazio, MD. Department of Surgery, Kaiser Permanente Medical Center, 1526 North Edgemont Street, Los Angeles, California 90027. Presented at the Seventh Annual Meeting of the Society for Clinical Vascular Surgery, Palm Springs, California, March 14-18, 1979.
246
Case Reports
Case I. A 19 year old white woman was admitted to the hospital because of pain and numbness in the left arm for 3 days. She had had intermittent pain and coolness in the left arm and hand for 3 months. Blood pressure was 110/84 mm Hg on the right side and inaudible on the left. Pulses were absent in the left arm and normal elsewhere. There was a poorly healing abrasion on the left middle finger. A left cervical rib was suggested by a chest X-ray film and confirmed by a cervical spine series. An arteriogram showed poststenotic dilatation and a large thrombus in the left subclavian artery at the level of the cervical rib, complete obstruction of the axillary artery, and multiple areas of embolization (Figures 1 and 2). After the medial portion of the clavicle was removed, the subclavian artery was noted to be severely compressed between the cervical rib and the scalenus anticus muscle. The artery was pulseless beyond the area of compression. The scalenus anticus muscle was divided and the cervical rib excised. The subclavian artery was opened longitudinally and found to be completely thrombosed distally. Thromboendarterectomy was performed and excellent forward flow achieved. The Fogarty catheter could not be passed more than a few centimeters distally; therefore, the brachial artery was approached in the arm. It contained much organized clot. It was difficult to pass the Fogarty catheter distally. Thrombectomy of the brachial artery and closure with a vein patch were performed. Shortly postoperatively the radial pulse disappeared and reoperation became necessary. Brachial thrombectomy was performed with the patient under local anesthesia, and an operative arteriogram showed a narrowed segment of brachial artery, multiple organized emboli, and a completely obstructed radial artery at the wrist (Figure 3). The radial pulse again disappeared, but the patient remained asymptomatic with no pulses below the brachial artery. A follow-up arteriogram at 6 weeks showed slight narrowing at the suture line in the subclavian artery with good flow into the brachial artery (Figure 4). Comment: This patient illustrates the difficulty frequently encountered in reestablishing distal pulses. Repeated embolization gradually occludes the distal vasculature before the major proximal occlusion [4]. Fortunately, collateral flow is usually suffi-
The American Journal of Surgery
Thoracic Outlet Syndrome
Figure 2. Case I. Subtraction film showing more clearly the thrombus in the subclavian artery. Figure 1. Case I. A subclavian injection showing complete obstruction of the axillary artery, poststenotic dilatation and thrombus in the subctavian artery, and multiple emboiiin the branches of the axillary artery.
Ftgure 3. Case 1. Operative brachiat arteriogram showing a narrowed segment of brachiat artery, muttiple organized emboli in the proximal ulnar and radial arteries, and complete obstruction of the radial artery at the wrist.
cient to preserve normal function obstruction is relieved.
if the proximal
Case II. A 71 year old white woman was hospitalized with severe pain in the left arm for 24 hours. She had a long history of pain and numbness in the left arm and fingers and had been treated for cervical radiculitis, lateral epicondylitis, and bursitis. The arm was painful, pale, cool, and pulseless. All other pulses were normal. The blood pressure on the left was inaudible and a hard mass thought to he a cervical rib was present in the left supraclavicular region. A chest X-ray film showed bilateral cervical ribs. The initial arteriogram showed complete occlusion of the left brachial artery only (Figure 5). The left subclavian artery was inadequately visualized. Because viability of the arm was in jeopardy, emergency brachial embolectomy was
Volume 138, August 1979
Figure 4. Case I. A 6 week postoperative arteriogram showing only sltght narrowing at the suture line in the subclavian artery and good flow into the brachtat artery,
performed with removal of numerous clots proximally and distally. The radial pulse was restored, but because thoracic outlet compression was suspected, a repeat subclavian arteriogram was taken. A subtraction film showed kinking and tortuosity of the subclavian artery and a large plaque at the level of the cervical rib (Figure 6). Again at operation through a supraclavicular incision with removal of the medial half of the clavicle, the artery was severely com-
247
Figure 5. Case II. Complete occlusion of the brachtal attery . with no demonstrable flow to We elbow.
pressed between the scalenus anticus muscle and the cervical rib. The muscle was divided, the rib excised, and the artery opened. It contained two areas of ulceration in a thick plaque. Endarterectomy was performed and the Fogarty catheter was passed, but apparently all clots had been removed during the previous brachial embolectomy. The patient remains asymptomatic with normal wrist pulses 4 years postoperatively.
Comment: This patient illustrates the difficulty that is sometimes encountered in angiographically demonstrating the proximal lesion in the subclavian artery. Subtraction films to eliminate the surrounding bony densities are frequently helpful. Case III. A 44 year old white woman was admitted with rest pain in the right arm of 1 week’s duration. She had a
Figure 6. Case II. A subtraction film showing kinking and tortuosity of the subclavian artery and a large plaque at the level of the cervical rib.
248
4 year history of right arm claudication. She had previously refused surgery at another hospital. There was no pulse and no audible blood pressure in the right arm. All other pulses were normal. No bony abnormalities were demonstrated by X-ray study. Angiography showed complete occlusion of the subclavian artery with excellent reconstitution distally (Figure 7). At operation through the same approach, complete occlusion of the subclavian artery with extension of thrombosis proximally to its origin was confirmed. In addition, a very thick strong fibrous band beneath the clavicle that was compressing the artery was excised. A right carotid-subclavian bypass graft was performed. Postoperatively, the rest pain was relieved, but wrist pulses did not return. Comment: This patient is unusual in that no bony abnormality was present; however, there was a thick fibrous band, which has been described by Roos (61 as occurring in most patients with thoracic outlet syndrome. Complete occlusion of the subclavian artery in the thoracic outlet syndrome can progress retrograde and result in stroke. [7]. Case IV. A 32 year old white man presented with pain of the right hand and forearm of 1 week’s duration. No pulses were palpable in the right arm below the axillary artery. Chest X-ray film showed an anomalous first rib which inserted on the second rib. Arteriography showed poststenotic dilatation of the subclavian artery with the arm at the side and complete occlusion with the arm abducted. In addition there was complete occlusion of the brachial artery above the elb.ow and numerous emboli in the subscapular, radial, and ulnar arteries (Figures 8 and 9). At operation through the same approach a large subclavian aneurysm was discovered, resected, and grafted, and numerous clots were extracted with the Fogarty catheter. Postoperatively, wrist pulses were restored and the patient was asymptomatic.
Figure 7. Case Ill. Complete occlusion of the subclavtan artery at the takeoff of the internal mammary artery.
The American Journal of Surgery
Thoracic Outlet Syndrome
Figure 8. Case IV. .Comp/ete occl~stofi of the subclavian artery with the grm abducted and a large embolus in the subscapular artery.
Figure 9. Case IV. Comptete occtusion of the bra&al artery above the elbow and multiple embolic occlusions of the radial and ulnar arteries.
Comment: Poststenotic dilatation may progress to an actual aneurysm, as this case illustrates. Angiography may fail to demonstrate the presence of the aneurysm because the lumen may be partially filled with clot. Aneurysms should be resected. Case V. A 37 year old white woman presented with pain in the right arm and hand for several months. A right subclavian aneurysm was palpable and there were no palpable pulses below the axillary artery. X-ray studies showed a right cervical rib. Arteriography with the arm at the side showed only mild poststeriotic dilatation of the subclavian artery (Figure 10). With the arm over head there was complete obstruction of the artery (Figure 11). In this case the subclavian artery extended so high into the neck that exposure was adequate with&t resection of the clavicle. The cervical and first ribs and the aneurysm were resected and end-to-end anastomosis was performed. The distal arterial tree could not be completely cleared of clot. The aneurysm contained mural thrombus. Postoperatively, the patient was. asymptomatic but without wrist pulses.
Figure 10. Case V. Poststenotic dilatation of the subclavian artery ivith the arm at the side.
6
Comment: Positional angiography must be interpreted with caution as many asymptomatic persons have obliteration or diminution of their pulses in various positions (81. Again the difficulty of clearing the distal vasculature is demonstrated. Comments
In 1853 Hilton [9] at Guy’s Hospital in London described subclavian artery compression by exostosis of the first rib. Coote [IO] in 1661 is credited with first excising a cervical rib for compression of the subclavian artery. Halstead [11] in 1916 produced poststenotic dilatation in his laboratory. Lewis and Pickering [5] in 1934 elucidated the role of thromVolume 138, August 1979
Figure 11. Case V. Complete occlusion of the subclavian artery with the arm abducted. 249
Dorazio and Ezzet
boembolism in the pathophysiology of arterial complications of the thoracic outlet syndrome. The sequence of events begins with mechanical compression of the subclavian artery by structures at the thoracic outlet such as the first rib, clavicle, cervical rib, scalenus anticus muscle, anomalous first ribs, elongated transverse processes, exostoses, healed fractures, and congenital fibrous bands. This compression, which may also rarely occur beneath the pectoralis minor tendon, results in turbulence and vibrations within the wall of the artery, leading to poststenotic dilatation or aneurysm. Mural thrombi form at the site of intimal damage. Distal embolization occurs repeatedly with secondary proximal and distal thrombosis, which results in ischemia, the severity of which depends on the site and extent of embolization and thrombosis. Throughout this process the patient experiences symptoms such as pain, numbness and tingling, and paresthesias. They are usually overlooked or thought to be neurologic, and the diagnosis is usually missed until the patient has a major ischemic episode. By this time the distal vasculature is usually so compromised that it is impossible to restore wrist pulses. Fortunately collateral circulation is usually sufficient to preclude major amputation, but minor amputation is not uncommon in this condition [4]. Early diagnosis is extremely important but rests largely on clinical grounds and requires a high index of suspicion. Pulse and blood pressure changes and bruits must be sought with the patient in various positions, but the frequency of these changes in normal persons must be kept in mind. Patients with arterial complications, unlike those with neurologic symptoms, usually have bony abnormalities. Cervical spine series may be helpful. Angiography is the most definitive study and should be performed at the first suspicion of arterial involvement. Views of the arch, the subclavian artery in various positions, and runoff to the digits should be included. The angiographic findings are frequently subtle and may appear normal in early cases. Even mild poststenotic dilatation in a symptomatic patient is diagnostic, and mural thrombi will usually be found at operation [12]. Of the various surgical approaches to the artery we prefer a supraclavicular incision with resection of the medial half or midportion of the clavicle. The exposure is superb and there is no functional impairment. The cosmetic results have been acceptable even in young women. Operation should aim at relieving the compression on the artery and removing the source of embolization as weli as the emboli themselves. This usually
250
requires removal of a cervical rib, thromboendarterectomy, if feasible, or resection of the artery and use of a Fogarty catheter. The artery may be quite friable and must be handled with care. Conclusions
Patients with arterial complications of the thoracic outlet syndrome must be distinguished from those with neurologic symptoms. They require immediate diagnosis and treatment to prevent serious consequences. Unfortunately the early signs and symptoms of arterial involvement are frequently unrecognized because they are nonspecific. Because of the role of thromboembolism, irreversible changes in the arterial circulation have usually occurred before the correct diagnosis is made. Therefore, only a minority of patients regain wrist pulses after surgery. A supraclavicular incision with resection of a portion of the clavicle gives excellent exposure and has no significant disadvantages. Acknowledgment: We wish to thank Drs. Edward Phillips and Stanley Christie for allowing us to include their cases.
References 1. Rob CG, Standeven A: Arterial occlusion complicating thoracic outlet compression syndrome. Er Med J 2: 709, 1958. 2. Roos DB: Transaxillary approach for first rib resection to relieve thoracic outlet syndrome. Ann Surg 163: 354, 1966. 3. Glass BA: The relationship of axillary venous thrombosis to the thoracic outlet compression syndrome. Ann 7hrac Surg 19: 613, 1975. 4. Judy KL, Heymann RL: Vascular complications of thoracic outlet syndrome. Am J Surg 123: 521, 1972. 5. Lewis T. Pickering GW: Observations upon maladies in which the blood supply to the digits closes intermittently or permanently and upon bilateral gangrene of the digits: observations relevant to so-called Raynaud’s disease. C/in Sci 1: 327, 1934. 6. Roos DB: Congenital anomalies associated with thoracic outlet syndrome, anatomy, symptoms, diagnosis and treatment. Am JSurg 132: 771, 1976. 7. Samiy E: Thrombosis of the internal carotid artery caused by a cervical rib. JNeurosurg 12: 181, 1955. 8. Winsor T, Brow R: Costoclavicular syndrome, diagnosis and treatment. JAMA 196: 697, 1966. 9. Hilton J: On Rest and Pain, 2nd edition. New York, William Wood and Co, 1879, p 113. 10. Coote H: Pressure on the axillary vessels and nerve by an exostosis from a cervical rib. Interference with the circulation of the arm. Removal of the rib in exostosis. Recovery. Med Times C&z 2: 108. 1861. 11. Halstead WS: An experimental study of circumscribed dilatation of an artery immediately distal to a partially occluding band and its bearing on the dilatation of the subclavian artery observed in certain cases of cervical rib. J Exp Med 24: 27 1, 1916. 12. Adler J, Hooshmand I: The angiographic spectrum of the thoracic outlet syndrome with emphasis on mural thrombosis and emboli and congenital vascular anomalies. C/in Radio/ 24: 35, 1973.
The American Journal of Surgery
The thoracic outlet syndrome is a symptom complex caused by compression of neurovascular structures at the thoracic outlet [I]. Neurologic symptoms are most common and often respond to physical therapy; when operation becomes necessary, excellent results are achieved with transaxillary resection of the first rib [2]. Vascular complications of the thoracic outlet may be venous or arterial. Many cases of axillary-subclavian venous thrombosis, such as “effort thrombosis,” probably represent the end result of thoracic outlet compression of the subclavian vein [3]. The role of surgical treatment of these patients is controversial. Arterial complications of the thoracic outlet syndrome are the least common but by far the most serious. These include poststenotic dilatation, mural thrombus, total occlusion, aneurysm, or any combination thereof [4]. They require urgent diagnostic and therapeutic measures. Unfortunately, the early signs and symptoms of arterial involvement are usually unrecognized. The basic pathophysiologic mechanism consists of repeated distal embolization from a proximal lesion in the subclavian artery [5]. Consequently, most patients have some degree of irreversible change in the circulation of the arm before the diagnosis is made. Surgical treatment is readily accomplished using a supraclavicular incision with resection of the clavicle to facilitate exposure. This approach allows simultaneous vascular repair and correction of the underlying thoracic outlet compression and has no significant cosmetic or functional disadvantages. Our experience with five patients constitutes the basis of this report.
From the Department of Surgery, Kaiser Permanente Medical Center, Los Angeles, California. Reprint requests should be addressed to Richard A. Dorazio, MD. Department of Surgery, Kaiser Permanente Medical Center, 1526 North Edgemont Street, Los Angeles, California 90027. Presented at the Seventh Annual Meeting of the Society for Clinical Vascular Surgery, Palm Springs, California, March 14-18, 1979.
246
Case Reports
Case I. A 19 year old white woman was admitted to the hospital because of pain and numbness in the left arm for 3 days. She had had intermittent pain and coolness in the left arm and hand for 3 months. Blood pressure was 110/84 mm Hg on the right side and inaudible on the left. Pulses were absent in the left arm and normal elsewhere. There was a poorly healing abrasion on the left middle finger. A left cervical rib was suggested by a chest X-ray film and confirmed by a cervical spine series. An arteriogram showed poststenotic dilatation and a large thrombus in the left subclavian artery at the level of the cervical rib, complete obstruction of the axillary artery, and multiple areas of embolization (Figures 1 and 2). After the medial portion of the clavicle was removed, the subclavian artery was noted to be severely compressed between the cervical rib and the scalenus anticus muscle. The artery was pulseless beyond the area of compression. The scalenus anticus muscle was divided and the cervical rib excised. The subclavian artery was opened longitudinally and found to be completely thrombosed distally. Thromboendarterectomy was performed and excellent forward flow achieved. The Fogarty catheter could not be passed more than a few centimeters distally; therefore, the brachial artery was approached in the arm. It contained much organized clot. It was difficult to pass the Fogarty catheter distally. Thrombectomy of the brachial artery and closure with a vein patch were performed. Shortly postoperatively the radial pulse disappeared and reoperation became necessary. Brachial thrombectomy was performed with the patient under local anesthesia, and an operative arteriogram showed a narrowed segment of brachial artery, multiple organized emboli, and a completely obstructed radial artery at the wrist (Figure 3). The radial pulse again disappeared, but the patient remained asymptomatic with no pulses below the brachial artery. A follow-up arteriogram at 6 weeks showed slight narrowing at the suture line in the subclavian artery with good flow into the brachial artery (Figure 4). Comment: This patient illustrates the difficulty frequently encountered in reestablishing distal pulses. Repeated embolization gradually occludes the distal vasculature before the major proximal occlusion [4]. Fortunately, collateral flow is usually suffi-
The American Journal of Surgery
Thoracic Outlet Syndrome
Figure 2. Case I. Subtraction film showing more clearly the thrombus in the subclavian artery. Figure 1. Case I. A subclavian injection showing complete obstruction of the axillary artery, poststenotic dilatation and thrombus in the subctavian artery, and multiple emboiiin the branches of the axillary artery.
Ftgure 3. Case 1. Operative brachiat arteriogram showing a narrowed segment of brachiat artery, muttiple organized emboli in the proximal ulnar and radial arteries, and complete obstruction of the radial artery at the wrist.
cient to preserve normal function obstruction is relieved.
if the proximal
Case II. A 71 year old white woman was hospitalized with severe pain in the left arm for 24 hours. She had a long history of pain and numbness in the left arm and fingers and had been treated for cervical radiculitis, lateral epicondylitis, and bursitis. The arm was painful, pale, cool, and pulseless. All other pulses were normal. The blood pressure on the left was inaudible and a hard mass thought to he a cervical rib was present in the left supraclavicular region. A chest X-ray film showed bilateral cervical ribs. The initial arteriogram showed complete occlusion of the left brachial artery only (Figure 5). The left subclavian artery was inadequately visualized. Because viability of the arm was in jeopardy, emergency brachial embolectomy was
Volume 138, August 1979
Figure 4. Case I. A 6 week postoperative arteriogram showing only sltght narrowing at the suture line in the subclavian artery and good flow into the brachtat artery,
performed with removal of numerous clots proximally and distally. The radial pulse was restored, but because thoracic outlet compression was suspected, a repeat subclavian arteriogram was taken. A subtraction film showed kinking and tortuosity of the subclavian artery and a large plaque at the level of the cervical rib (Figure 6). Again at operation through a supraclavicular incision with removal of the medial half of the clavicle, the artery was severely com-
247
Figure 5. Case II. Complete occlusion of the brachtal attery . with no demonstrable flow to We elbow.
pressed between the scalenus anticus muscle and the cervical rib. The muscle was divided, the rib excised, and the artery opened. It contained two areas of ulceration in a thick plaque. Endarterectomy was performed and the Fogarty catheter was passed, but apparently all clots had been removed during the previous brachial embolectomy. The patient remains asymptomatic with normal wrist pulses 4 years postoperatively.
Comment: This patient illustrates the difficulty that is sometimes encountered in angiographically demonstrating the proximal lesion in the subclavian artery. Subtraction films to eliminate the surrounding bony densities are frequently helpful. Case III. A 44 year old white woman was admitted with rest pain in the right arm of 1 week’s duration. She had a
Figure 6. Case II. A subtraction film showing kinking and tortuosity of the subclavian artery and a large plaque at the level of the cervical rib.
248
4 year history of right arm claudication. She had previously refused surgery at another hospital. There was no pulse and no audible blood pressure in the right arm. All other pulses were normal. No bony abnormalities were demonstrated by X-ray study. Angiography showed complete occlusion of the subclavian artery with excellent reconstitution distally (Figure 7). At operation through the same approach, complete occlusion of the subclavian artery with extension of thrombosis proximally to its origin was confirmed. In addition, a very thick strong fibrous band beneath the clavicle that was compressing the artery was excised. A right carotid-subclavian bypass graft was performed. Postoperatively, the rest pain was relieved, but wrist pulses did not return. Comment: This patient is unusual in that no bony abnormality was present; however, there was a thick fibrous band, which has been described by Roos (61 as occurring in most patients with thoracic outlet syndrome. Complete occlusion of the subclavian artery in the thoracic outlet syndrome can progress retrograde and result in stroke. [7]. Case IV. A 32 year old white man presented with pain of the right hand and forearm of 1 week’s duration. No pulses were palpable in the right arm below the axillary artery. Chest X-ray film showed an anomalous first rib which inserted on the second rib. Arteriography showed poststenotic dilatation of the subclavian artery with the arm at the side and complete occlusion with the arm abducted. In addition there was complete occlusion of the brachial artery above the elb.ow and numerous emboli in the subscapular, radial, and ulnar arteries (Figures 8 and 9). At operation through the same approach a large subclavian aneurysm was discovered, resected, and grafted, and numerous clots were extracted with the Fogarty catheter. Postoperatively, wrist pulses were restored and the patient was asymptomatic.
Figure 7. Case Ill. Complete occlusion of the subclavtan artery at the takeoff of the internal mammary artery.
The American Journal of Surgery
Thoracic Outlet Syndrome
Figure 8. Case IV. .Comp/ete occl~stofi of the subclavian artery with the grm abducted and a large embolus in the subscapular artery.
Figure 9. Case IV. Comptete occtusion of the bra&al artery above the elbow and multiple embolic occlusions of the radial and ulnar arteries.
Comment: Poststenotic dilatation may progress to an actual aneurysm, as this case illustrates. Angiography may fail to demonstrate the presence of the aneurysm because the lumen may be partially filled with clot. Aneurysms should be resected. Case V. A 37 year old white woman presented with pain in the right arm and hand for several months. A right subclavian aneurysm was palpable and there were no palpable pulses below the axillary artery. X-ray studies showed a right cervical rib. Arteriography with the arm at the side showed only mild poststeriotic dilatation of the subclavian artery (Figure 10). With the arm over head there was complete obstruction of the artery (Figure 11). In this case the subclavian artery extended so high into the neck that exposure was adequate with&t resection of the clavicle. The cervical and first ribs and the aneurysm were resected and end-to-end anastomosis was performed. The distal arterial tree could not be completely cleared of clot. The aneurysm contained mural thrombus. Postoperatively, the patient was. asymptomatic but without wrist pulses.
Figure 10. Case V. Poststenotic dilatation of the subclavian artery ivith the arm at the side.
6
Comment: Positional angiography must be interpreted with caution as many asymptomatic persons have obliteration or diminution of their pulses in various positions (81. Again the difficulty of clearing the distal vasculature is demonstrated. Comments
In 1853 Hilton [9] at Guy’s Hospital in London described subclavian artery compression by exostosis of the first rib. Coote [IO] in 1661 is credited with first excising a cervical rib for compression of the subclavian artery. Halstead [11] in 1916 produced poststenotic dilatation in his laboratory. Lewis and Pickering [5] in 1934 elucidated the role of thromVolume 138, August 1979
Figure 11. Case V. Complete occlusion of the subclavian artery with the arm abducted. 249
Dorazio and Ezzet
boembolism in the pathophysiology of arterial complications of the thoracic outlet syndrome. The sequence of events begins with mechanical compression of the subclavian artery by structures at the thoracic outlet such as the first rib, clavicle, cervical rib, scalenus anticus muscle, anomalous first ribs, elongated transverse processes, exostoses, healed fractures, and congenital fibrous bands. This compression, which may also rarely occur beneath the pectoralis minor tendon, results in turbulence and vibrations within the wall of the artery, leading to poststenotic dilatation or aneurysm. Mural thrombi form at the site of intimal damage. Distal embolization occurs repeatedly with secondary proximal and distal thrombosis, which results in ischemia, the severity of which depends on the site and extent of embolization and thrombosis. Throughout this process the patient experiences symptoms such as pain, numbness and tingling, and paresthesias. They are usually overlooked or thought to be neurologic, and the diagnosis is usually missed until the patient has a major ischemic episode. By this time the distal vasculature is usually so compromised that it is impossible to restore wrist pulses. Fortunately collateral circulation is usually sufficient to preclude major amputation, but minor amputation is not uncommon in this condition [4]. Early diagnosis is extremely important but rests largely on clinical grounds and requires a high index of suspicion. Pulse and blood pressure changes and bruits must be sought with the patient in various positions, but the frequency of these changes in normal persons must be kept in mind. Patients with arterial complications, unlike those with neurologic symptoms, usually have bony abnormalities. Cervical spine series may be helpful. Angiography is the most definitive study and should be performed at the first suspicion of arterial involvement. Views of the arch, the subclavian artery in various positions, and runoff to the digits should be included. The angiographic findings are frequently subtle and may appear normal in early cases. Even mild poststenotic dilatation in a symptomatic patient is diagnostic, and mural thrombi will usually be found at operation [12]. Of the various surgical approaches to the artery we prefer a supraclavicular incision with resection of the medial half or midportion of the clavicle. The exposure is superb and there is no functional impairment. The cosmetic results have been acceptable even in young women. Operation should aim at relieving the compression on the artery and removing the source of embolization as weli as the emboli themselves. This usually
250
requires removal of a cervical rib, thromboendarterectomy, if feasible, or resection of the artery and use of a Fogarty catheter. The artery may be quite friable and must be handled with care. Conclusions
Patients with arterial complications of the thoracic outlet syndrome must be distinguished from those with neurologic symptoms. They require immediate diagnosis and treatment to prevent serious consequences. Unfortunately the early signs and symptoms of arterial involvement are frequently unrecognized because they are nonspecific. Because of the role of thromboembolism, irreversible changes in the arterial circulation have usually occurred before the correct diagnosis is made. Therefore, only a minority of patients regain wrist pulses after surgery. A supraclavicular incision with resection of a portion of the clavicle gives excellent exposure and has no significant disadvantages. Acknowledgment: We wish to thank Drs. Edward Phillips and Stanley Christie for allowing us to include their cases.
References 1. Rob CG, Standeven A: Arterial occlusion complicating thoracic outlet compression syndrome. Er Med J 2: 709, 1958. 2. Roos DB: Transaxillary approach for first rib resection to relieve thoracic outlet syndrome. Ann Surg 163: 354, 1966. 3. Glass BA: The relationship of axillary venous thrombosis to the thoracic outlet compression syndrome. Ann 7hrac Surg 19: 613, 1975. 4. Judy KL, Heymann RL: Vascular complications of thoracic outlet syndrome. Am J Surg 123: 521, 1972. 5. Lewis T. Pickering GW: Observations upon maladies in which the blood supply to the digits closes intermittently or permanently and upon bilateral gangrene of the digits: observations relevant to so-called Raynaud’s disease. C/in Sci 1: 327, 1934. 6. Roos DB: Congenital anomalies associated with thoracic outlet syndrome, anatomy, symptoms, diagnosis and treatment. Am JSurg 132: 771, 1976. 7. Samiy E: Thrombosis of the internal carotid artery caused by a cervical rib. JNeurosurg 12: 181, 1955. 8. Winsor T, Brow R: Costoclavicular syndrome, diagnosis and treatment. JAMA 196: 697, 1966. 9. Hilton J: On Rest and Pain, 2nd edition. New York, William Wood and Co, 1879, p 113. 10. Coote H: Pressure on the axillary vessels and nerve by an exostosis from a cervical rib. Interference with the circulation of the arm. Removal of the rib in exostosis. Recovery. Med Times C&z 2: 108. 1861. 11. Halstead WS: An experimental study of circumscribed dilatation of an artery immediately distal to a partially occluding band and its bearing on the dilatation of the subclavian artery observed in certain cases of cervical rib. J Exp Med 24: 27 1, 1916. 12. Adler J, Hooshmand I: The angiographic spectrum of the thoracic outlet syndrome with emphasis on mural thrombosis and emboli and congenital vascular anomalies. C/in Radio/ 24: 35, 1973.
The American Journal of Surgery
