The Thoracic Outlet David B.
Roos,
developmental anatomic anomalies of musculoskeletal tissues that cause abnormal compression and irritation of the brachial plexus and subclavian vessels. The most obvious anomaly is a cervical rib, but this is found in only about 10% of patients with TOS. The other 90% who develop severe neuromuscular symptoms affecting the neck, shoulder, and upper extremity are found to have soft-tissue anomalies usually related to the middle and anterior scalene muscles. Although these anomalies have been carefully classified and reported,1,2 only the surgical team can appreciate the remarkable anatomic variations that cause the severe neurovascular symptoms. Extensive (and expensive), sophisticated neuroelectric studies, magnetic resonance imagcaused
by congenital
or
scans, computed tomography scans, and vascular laboratory studies completely fail to demonstrate the an-
ing
atomic variations of the soft tissues and the neurologic compression-irritation mechanisms that are the basic cause of the symptoms.3,4 Thus, the physician must rely on his clinical experience and diagnostic acumen to evaluate adequately the conditions of patients with neurovascular com¬
plaints of the
Is Underrated
MD
The thoracic outlet syndromes (TOS) are
Syndrome
upper extremities.
I have found significant soft-tissue anomalies in the thoracic outlet and scalene triangle not illustrated in anatomy textbooks in 33% of cadaver dissections. This indicates a surpris¬ ingly high incidence of anatomic sus¬ ceptibility of the normal population to have the neurovascular symptoms deAccepted for publication April 13,1989. From the Department of Surgery, University of Colorado Health Sciences Center, Denver. Reprint requests to 1721 E 19th Ave, Suite 138, Denver, CO 80218-1235 (Dr Roos).
velop that we categorize as TOS. With such a high incidence of these ana¬ tomic variations, one wonders not why do severe complaints arise from neu¬ rovascular compression, but why are they not more common than they are? Of the three major categories of TOS, neurologic, venous, and arterial, the neurologic type, caused by com¬ pression or irritation of the nerves of the brachial plexus, is by far the most common, constituting about 97% of all
of TOS. This type may be further divided into two groups, depending on which nerves are specifically involved. In the upper plexus involvement, the C-5, C-6, and C-7 nerves are primarily affected by abnormally formed scalene muscles in relation to the upper three nerves usually combined with chronic spasm of the cervical muscles. This produces pain over the brachial plexus radiating from the ear through the anterior cervical region over the clav¬ icle into the upper part of the chest, posteriorly into the rhomboid and scapular areas, and laterally across the trapezius ridge and down the outer arm into the radial aspect of the fore¬ arm in a typical C5-6 distribution. The lower plexus type is different. Compression by abnormal muscle and congenital bands on the C-8 and T-l nerves causes pain in the supraclavicular and infraclavicular fossae, radi¬ ating into the upper part of the back and from the axilla down the inner arm through the ulnar nerve distribu¬ tion to the ring and small fingers. Pa¬ tients may present with either pattern or with a combination of both. It re¬ quires considerable time to delineate these patterns by detailed history and thorough physical examination. One must test the various areas of the neck, shoulders, and arms for local tender¬ ness, muscle spasm, weakness, and hypoesthesias in specific nerve distribucases
Downloaded From: http://archneur.jamanetwork.com/ by a New York University User on 05/22/2015
tions and muscle groups. Simply ob¬ taining chief complaints of pain in the neck, shoulder, and arm with pares¬ thesias, raising the arm to check the pulse, and then sending the patient off for neuroelectric, vascular laboratory, and angiography studies is a common practice to be condemned. These ex¬ pensive studies cannot establish the diagnosis; the patient is left with huge bills and no effective plan of treatment. Most patients are optimistically sent to physical therapy where the standard exercise program usually ag¬ gravates the muscle spasm compres¬ sion and irritation of the plexus, thus exacerbating the symptoms, which then makes the diagnosis and the pa¬ tient's veracity suspect. Patients be¬ come frustrated, even angry that their complaints are not taken seriously; no specific diagnosis results and the only treatment offered makes them worse. Some are dismissed with multiple pre¬ scriptions for narcotics and anxiolytic medications that further infuriate the recipient and make the muscle con¬ traction headaches and plexus com¬
pression worse. In an ongoing Odyssey from one re¬ ferral to another as patients desper¬ ately seek relief, the next physician encountered sees mainly the frustra¬ tion, anxiety, and anger that have de¬ veloped from the increasingly severe symptoms that affect the patient's family life, job, sleep, and mental wellbeing in a progressively deteriorating manner. The underlying neuroanatomic causes and specific symptom patterns may be masked and
com¬
pletely overlooked. If this emotional facade can be pierced with empathy and diagnostic accuracy, the underly¬ ing TOS may still be amenable to appropriate treatment. Soothing types of therapy, using heat or ice, ultrasound, infrared heat,
and transcutaneous nerve stimulation devices along with biofeedback, mus¬ cle relaxants, nonsteroidal antiinflammatory drugs, and sleeping medication to try to establish normal sleep patterns to promote emotional and neuromuscular relaxation can be offered for several weeks or months to see if the brachial plexus irritation abates and the symptoms become more tolerable. In early and mild cases, the results may be gratifying, but in more advanced cases, the symptoms and
neurologic compression are usually too severe for these therapeutic modalities to be effective, and only mechanical
anatomic alteration has a chance to offer resolution of the progressively
incapacitating symptoms.
For the most common type of TOS, the lower plexus involvement, removal of the bony floor of the thoracic outlet and the first rib and cervical rib if
present, along with the anomalous fi-
bromuscular bands that are always found in carefully selected patients, will offer gratifying relief in 80% to 90% of patients with severe symp¬ toms.5·6 This is most safely and ade¬
quately accomplished through a transaxillary approach. If the upper plexus is predominantly involved, supraclavicular anterior scalenectomy, as distinguished from the obsolete scalenotomy used in the 1930s and 1940s,
offering
the
Although complications of such
op¬
has the best chance of most relief available.2·7
erations
can
be severe, in the form of
life-threatening hemorrhage, perma¬ nent neurologic deficit of the arm and hand from brachial plexus injury, and winged scapula from long thoracic nerve trauma, such complications are rare.2 In many cases, the most gratify¬ ing results are the remarkable relief of
severe
headaches,
return to normal
sleep patterns, and relief of the sec¬ ondary emotional reactions of frustra¬ tion, anger, and irritability. Dealing with patients who have TOS requires thorough knowledge of the various symptom complexes and great patience with people suffering severe, often incapacitating and frightening symptoms that they or their previous physicians do not understand. How¬ ever, if an accurate diagnosis is made, if surgical candidates are chosen with care, and if the appropriate operations are performed with meticulous tech¬ nique, significant, if not total, relief is the happy outcome in the majority of patients, even after all attempts at
conservative treatment have failed. These often neglected patients may become some of the most gratified and appreciative people we see in our neu¬ rologic and surgical practices.
References 1. Roos DB. Congenital anomalies associated with thoracic outlet syndrome: anatomy, symptoms, diagnosis and treatment. Am J Surg.
1976;132:771-778.
2. Roos DB. The place for scalenectomy and first rib resection in thoracic outlet syndrome.
Surgery. 1982;92:1077-1085.
3. Daub JR. Nerve conduction studies in the
The Thoracic Outlet Asa J.
promise of the neurovascular
struc-
tures\p=m-\subclavian/axillaryartery and
vein, distal cervical roots, brachial plexus fibers\p=m-\traversingthe thoracic outlet.1 Thoracic outlet syndrome can be subdivided into four distinct sub-
groups, depending on the particular structure affected, because seldom is
than
one
involved simultane-
ously.2 These subgroups are arterial vascular, venous vascular, true (or classic) neurologic, and disputed neurologic.3 The first three types are
noncontroversial. Because of space limitations the vascular types cannot be discussed in detail; detailed descriptions of them are available.3-6 They share several common features with Accepted for publication April 13, 1989. From the Electromyography Laboratory, Neurology Department, Cleveland (Ohio) Clinic Foun-
dation.
Reprint requests to Electromyography Laboratory, Neurology Department, Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195
outlet syndrome. Am J Surg. 1979;138:175-181. 7. Qvarfordt PG, Ehrenfeld WK, Stoney RJ. Supraclavicular radical scalenectomy and transaxillary first rib resection for the thoracic outlet syndrome: a combined approach. Am J Surg.
1984;148:111-116.
1971;173:429-433. 6. Etheredge S, Wilbur B, Stoney RJ. Thoracic
Syndrome Is Overdiagnosed
Wilbourn, MD
Thoracic outlet syndrome (TOS) refers to disorders attributed to com-
more
thoracic outlet syndrome. Neurology. 1975;25:347. 4. Raskin NH, Howard MW, Ehrenfeld WK. Headache as the leading symptom of the thoracic outlet syndrome. Headache. 1985;25:208-210. 5. Roos DB. Experience with first rib resection for thoracic outlet syndrome. Ann Surg.
(Dr Wilbourn).
the true neurologic type (true N-TOS), including characteristic symptom profile, obvious clinical findings, confirmatory results of laboratory studies, worldwide recognition as an entity, and low incidence. For example, true N-TOS is a rare lesion that occurs unilaterally and primarily affects adult women. Caused by the distal C-8/T-1 roots or proximal lower trunk of brachial plexus fibers being stretched over a taut congenital band extending from the first rib to a rudimentary cervical rib, it presents with a long history of sensory symptoms along mainly the medial forearm, associated with hand weakness and wasting, particularly of the lateral thenar muscles. Helpful laboratory studies include roentgenograms that reveal the bony abnormal¬ ity (but not the cervical band) and electromyographic examination that shows a chronic, severe, axon loss lower trunk brachial plexopathy. Sec¬ tioning the band relieves sensory symptoms and stops progression of the motor abnormalities.3,7,8 In contrast, the remaining sub-
Downloaded From: http://archneur.jamanetwork.com/ by a New York University User on 05/22/2015
disputed neurologic TOS (dis¬ puted N-TOS), possesses none of the above characteristics. Instead, it has many unique features, unparalleled in the field of peripheral neurology. First, although reputedly a neuro¬ logic disorder, disputed N-TOS rarely is mentioned in the neurologic litera¬ ture; it owes its origin and most of its popularity to non-neurologically trained physicians, particularly tho¬ racic surgeons. It is predominantly a group,
revival of the scalenus anticus syn¬
drome, often diagnosed in the 1940s and 1950s, and attributed to compres¬ sion of the brachial plexus, particu¬ larly the lower trunk, by an abnormal
scalenus anticus muscle. Scalenus an¬ ticus syndrome lost its credibility after carpal tunnel syndrome and cervical radiculopathy were recognized, and its high surgical failure rate (60%) be¬ came known.23 Disputed N-TOS origi¬ nated in 1962, when Clagett9 proposed first thoracic rib removal to treat all the entities then considered subtypes of TOS, convinced that the rib was the "common denominator" in their symp-
Roos,
developmental anatomic anomalies of musculoskeletal tissues that cause abnormal compression and irritation of the brachial plexus and subclavian vessels. The most obvious anomaly is a cervical rib, but this is found in only about 10% of patients with TOS. The other 90% who develop severe neuromuscular symptoms affecting the neck, shoulder, and upper extremity are found to have soft-tissue anomalies usually related to the middle and anterior scalene muscles. Although these anomalies have been carefully classified and reported,1,2 only the surgical team can appreciate the remarkable anatomic variations that cause the severe neurovascular symptoms. Extensive (and expensive), sophisticated neuroelectric studies, magnetic resonance imagcaused
by congenital
or
scans, computed tomography scans, and vascular laboratory studies completely fail to demonstrate the an-
ing
atomic variations of the soft tissues and the neurologic compression-irritation mechanisms that are the basic cause of the symptoms.3,4 Thus, the physician must rely on his clinical experience and diagnostic acumen to evaluate adequately the conditions of patients with neurovascular com¬
plaints of the
Is Underrated
MD
The thoracic outlet syndromes (TOS) are
Syndrome
upper extremities.
I have found significant soft-tissue anomalies in the thoracic outlet and scalene triangle not illustrated in anatomy textbooks in 33% of cadaver dissections. This indicates a surpris¬ ingly high incidence of anatomic sus¬ ceptibility of the normal population to have the neurovascular symptoms deAccepted for publication April 13,1989. From the Department of Surgery, University of Colorado Health Sciences Center, Denver. Reprint requests to 1721 E 19th Ave, Suite 138, Denver, CO 80218-1235 (Dr Roos).
velop that we categorize as TOS. With such a high incidence of these ana¬ tomic variations, one wonders not why do severe complaints arise from neu¬ rovascular compression, but why are they not more common than they are? Of the three major categories of TOS, neurologic, venous, and arterial, the neurologic type, caused by com¬ pression or irritation of the nerves of the brachial plexus, is by far the most common, constituting about 97% of all
of TOS. This type may be further divided into two groups, depending on which nerves are specifically involved. In the upper plexus involvement, the C-5, C-6, and C-7 nerves are primarily affected by abnormally formed scalene muscles in relation to the upper three nerves usually combined with chronic spasm of the cervical muscles. This produces pain over the brachial plexus radiating from the ear through the anterior cervical region over the clav¬ icle into the upper part of the chest, posteriorly into the rhomboid and scapular areas, and laterally across the trapezius ridge and down the outer arm into the radial aspect of the fore¬ arm in a typical C5-6 distribution. The lower plexus type is different. Compression by abnormal muscle and congenital bands on the C-8 and T-l nerves causes pain in the supraclavicular and infraclavicular fossae, radi¬ ating into the upper part of the back and from the axilla down the inner arm through the ulnar nerve distribu¬ tion to the ring and small fingers. Pa¬ tients may present with either pattern or with a combination of both. It re¬ quires considerable time to delineate these patterns by detailed history and thorough physical examination. One must test the various areas of the neck, shoulders, and arms for local tender¬ ness, muscle spasm, weakness, and hypoesthesias in specific nerve distribucases
Downloaded From: http://archneur.jamanetwork.com/ by a New York University User on 05/22/2015
tions and muscle groups. Simply ob¬ taining chief complaints of pain in the neck, shoulder, and arm with pares¬ thesias, raising the arm to check the pulse, and then sending the patient off for neuroelectric, vascular laboratory, and angiography studies is a common practice to be condemned. These ex¬ pensive studies cannot establish the diagnosis; the patient is left with huge bills and no effective plan of treatment. Most patients are optimistically sent to physical therapy where the standard exercise program usually ag¬ gravates the muscle spasm compres¬ sion and irritation of the plexus, thus exacerbating the symptoms, which then makes the diagnosis and the pa¬ tient's veracity suspect. Patients be¬ come frustrated, even angry that their complaints are not taken seriously; no specific diagnosis results and the only treatment offered makes them worse. Some are dismissed with multiple pre¬ scriptions for narcotics and anxiolytic medications that further infuriate the recipient and make the muscle con¬ traction headaches and plexus com¬
pression worse. In an ongoing Odyssey from one re¬ ferral to another as patients desper¬ ately seek relief, the next physician encountered sees mainly the frustra¬ tion, anxiety, and anger that have de¬ veloped from the increasingly severe symptoms that affect the patient's family life, job, sleep, and mental wellbeing in a progressively deteriorating manner. The underlying neuroanatomic causes and specific symptom patterns may be masked and
com¬
pletely overlooked. If this emotional facade can be pierced with empathy and diagnostic accuracy, the underly¬ ing TOS may still be amenable to appropriate treatment. Soothing types of therapy, using heat or ice, ultrasound, infrared heat,
and transcutaneous nerve stimulation devices along with biofeedback, mus¬ cle relaxants, nonsteroidal antiinflammatory drugs, and sleeping medication to try to establish normal sleep patterns to promote emotional and neuromuscular relaxation can be offered for several weeks or months to see if the brachial plexus irritation abates and the symptoms become more tolerable. In early and mild cases, the results may be gratifying, but in more advanced cases, the symptoms and
neurologic compression are usually too severe for these therapeutic modalities to be effective, and only mechanical
anatomic alteration has a chance to offer resolution of the progressively
incapacitating symptoms.
For the most common type of TOS, the lower plexus involvement, removal of the bony floor of the thoracic outlet and the first rib and cervical rib if
present, along with the anomalous fi-
bromuscular bands that are always found in carefully selected patients, will offer gratifying relief in 80% to 90% of patients with severe symp¬ toms.5·6 This is most safely and ade¬
quately accomplished through a transaxillary approach. If the upper plexus is predominantly involved, supraclavicular anterior scalenectomy, as distinguished from the obsolete scalenotomy used in the 1930s and 1940s,
offering
the
Although complications of such
op¬
has the best chance of most relief available.2·7
erations
can
be severe, in the form of
life-threatening hemorrhage, perma¬ nent neurologic deficit of the arm and hand from brachial plexus injury, and winged scapula from long thoracic nerve trauma, such complications are rare.2 In many cases, the most gratify¬ ing results are the remarkable relief of
severe
headaches,
return to normal
sleep patterns, and relief of the sec¬ ondary emotional reactions of frustra¬ tion, anger, and irritability. Dealing with patients who have TOS requires thorough knowledge of the various symptom complexes and great patience with people suffering severe, often incapacitating and frightening symptoms that they or their previous physicians do not understand. How¬ ever, if an accurate diagnosis is made, if surgical candidates are chosen with care, and if the appropriate operations are performed with meticulous tech¬ nique, significant, if not total, relief is the happy outcome in the majority of patients, even after all attempts at
conservative treatment have failed. These often neglected patients may become some of the most gratified and appreciative people we see in our neu¬ rologic and surgical practices.
References 1. Roos DB. Congenital anomalies associated with thoracic outlet syndrome: anatomy, symptoms, diagnosis and treatment. Am J Surg.
1976;132:771-778.
2. Roos DB. The place for scalenectomy and first rib resection in thoracic outlet syndrome.
Surgery. 1982;92:1077-1085.
3. Daub JR. Nerve conduction studies in the
The Thoracic Outlet Asa J.
promise of the neurovascular
struc-
tures\p=m-\subclavian/axillaryartery and
vein, distal cervical roots, brachial plexus fibers\p=m-\traversingthe thoracic outlet.1 Thoracic outlet syndrome can be subdivided into four distinct sub-
groups, depending on the particular structure affected, because seldom is
than
one
involved simultane-
ously.2 These subgroups are arterial vascular, venous vascular, true (or classic) neurologic, and disputed neurologic.3 The first three types are
noncontroversial. Because of space limitations the vascular types cannot be discussed in detail; detailed descriptions of them are available.3-6 They share several common features with Accepted for publication April 13, 1989. From the Electromyography Laboratory, Neurology Department, Cleveland (Ohio) Clinic Foun-
dation.
Reprint requests to Electromyography Laboratory, Neurology Department, Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195
outlet syndrome. Am J Surg. 1979;138:175-181. 7. Qvarfordt PG, Ehrenfeld WK, Stoney RJ. Supraclavicular radical scalenectomy and transaxillary first rib resection for the thoracic outlet syndrome: a combined approach. Am J Surg.
1984;148:111-116.
1971;173:429-433. 6. Etheredge S, Wilbur B, Stoney RJ. Thoracic
Syndrome Is Overdiagnosed
Wilbourn, MD
Thoracic outlet syndrome (TOS) refers to disorders attributed to com-
more
thoracic outlet syndrome. Neurology. 1975;25:347. 4. Raskin NH, Howard MW, Ehrenfeld WK. Headache as the leading symptom of the thoracic outlet syndrome. Headache. 1985;25:208-210. 5. Roos DB. Experience with first rib resection for thoracic outlet syndrome. Ann Surg.
(Dr Wilbourn).
the true neurologic type (true N-TOS), including characteristic symptom profile, obvious clinical findings, confirmatory results of laboratory studies, worldwide recognition as an entity, and low incidence. For example, true N-TOS is a rare lesion that occurs unilaterally and primarily affects adult women. Caused by the distal C-8/T-1 roots or proximal lower trunk of brachial plexus fibers being stretched over a taut congenital band extending from the first rib to a rudimentary cervical rib, it presents with a long history of sensory symptoms along mainly the medial forearm, associated with hand weakness and wasting, particularly of the lateral thenar muscles. Helpful laboratory studies include roentgenograms that reveal the bony abnormal¬ ity (but not the cervical band) and electromyographic examination that shows a chronic, severe, axon loss lower trunk brachial plexopathy. Sec¬ tioning the band relieves sensory symptoms and stops progression of the motor abnormalities.3,7,8 In contrast, the remaining sub-
Downloaded From: http://archneur.jamanetwork.com/ by a New York University User on 05/22/2015
disputed neurologic TOS (dis¬ puted N-TOS), possesses none of the above characteristics. Instead, it has many unique features, unparalleled in the field of peripheral neurology. First, although reputedly a neuro¬ logic disorder, disputed N-TOS rarely is mentioned in the neurologic litera¬ ture; it owes its origin and most of its popularity to non-neurologically trained physicians, particularly tho¬ racic surgeons. It is predominantly a group,
revival of the scalenus anticus syn¬
drome, often diagnosed in the 1940s and 1950s, and attributed to compres¬ sion of the brachial plexus, particu¬ larly the lower trunk, by an abnormal
scalenus anticus muscle. Scalenus an¬ ticus syndrome lost its credibility after carpal tunnel syndrome and cervical radiculopathy were recognized, and its high surgical failure rate (60%) be¬ came known.23 Disputed N-TOS origi¬ nated in 1962, when Clagett9 proposed first thoracic rib removal to treat all the entities then considered subtypes of TOS, convinced that the rib was the "common denominator" in their symp-
