A 34-year-old right-handed woman complains of increasing and debilitating pain and paresthesia along her right fifth finger, radiating up the medial aspect of her arm when working at her job as a hair stylist. Scalene and hyperabduction tests are both positive, chest x-ray and cervical spine films are normal, and ulnar nerve conduction velocity over the thoracic inlet is 68 meters per second. Which of the following is the most appropriate next step in management?

A. physical therapy to strengthen the shoulder girdle
B. recommendation for job-related disability and career change
C. right upper extremity angiography
D. supraclavicular scalenectomy
E. transaxillary resection of the right first rib 

Answer A

Thoracic outlet syndrome (TOS) occurs when there is compression of the 
subclavian vessels and/or brachial plexus, usually between the clavicle and the first rib. This 
may occur because of trauma, congenital cervical rib, or vestigial fibrous bands. Repetitive 
stress disorder is another etiology, as in the hairdresser described, in whom frequent elevation 
of the arms increases pressure on the lower trunk of the brachial plexus. Symptoms are varied 
and are more commonly neurologic, consisting of pain and paresthesias, most commonly in areas 
supplied by the ulnar nerve. Symptoms of arterial compression or, less frequently, venous 
obstruction may occur with or without neurologic symptoms and each may be precipitated by 
strenuous physical exercises or sustained physical efforts of the arm in abduction. The scalene 
(Adson's) and hyperabduction tests are both suggestive of the diagnosis of thoracic outlet 
syndrome in a patient with this history. Chest radiograph and cervical spine films are important 
in the evaluation to exclude surgical ribs, osteophytes, or intervertebral space narrowing. 

Somatosensory evoked potentials (SSEPs) or nerve conduction studies can provide important 
documentation of abnormal nerve function due to compression. The normal ulnar nerve conduction 
velocities are 72 meters per second or higher across the thoracic outlet, and this patient's 
mildly decreased velocity is consistent with the diagnosis of thoracic outlet syndrome. However, 
this diminution of velocity is not considered to be severe until it is less than 54 meters per 
second. 

Many of the symptoms of thoracic outlet syndrome are the consequence of poor posture, 
muscle strain, and muscle imbalance. Significant improvement by physical therapy is common. 
Virtually all patients with neurogenic symptoms related to thoracic outlet syndrome deserve a 
trial of physical therapy for strengthening of the neck and shoulder muscles and improvement of 
posture. Most patients with thoracic outlet syndrome with ulnar nerve conduction velocities of 
more than 60 meters per second improve with this type of conservative management. 

In some cases, job demands make it difficult to eliminate repetitive stress and may exacerbate the 
thoracic outlet syndrome. A job change may occasionally be necessary, but only after education 
and physical therapy have failed and after consideration of the relative benefits of a change in 
employment versus surgical intervention. 

There is no indication in this case of vascular insufficiency so workup including angiography is not necessary. 

Surgery for thoracic outlet syndrome, whether it be a scalenectomy or a resection of the first rib, is performed only if there are persistent symptoms after attempts at conservative therapy.



Sanders RJ, Haug C. Review of arterial thoracic outlet syndrome with a report of five new instances. Surg 
Gynecol Obstet 1991;173:415-25.
Arterial damage, causing ischemia of the limb, occurs in less than 5 percent of all 
instances of thoracic outlet syndrome. Arterial complications are usually associated with 
cervical ribs or rudimentary first ribs, but 12 percent have occurred in patients with no osseous 
abnormality. The physiopathologic factors begin with compression of the subclavian artery which, 
in most patients, produces stenosis, poststenotic dilatation, formation of aneurysms and mural 
thrombosis. In other patients, aneurysms do not form, but the compression still causes stenosis, 
intimal injury and mural thrombosis. With either scenario, distal embolization can occur and 
produce signs and symptoms of ischemia that can limb- threatening. In this study, more than 200 
patients reported previously and five additional sides in four patients were reviewed. Treatment 
depends upon the condition of the patient at presentation. Those with osseous abnormalities and 
no aneurysm or symptoms are not treated, while those with poststenotic dilatation or small 
aneurysms undergo rib resection only. Aneurysms more than twice the arterial diameter, intimal 
injury, or mural thrombus are indications to resect, replace, or bypass the subclavian artery. 
Patients who have had distal embolization and severe ischemic symptoms require, in addition to 
the aforementioned, distal thromboembolectomy, dorsal sympathectomy, or both. Good results from 
treatment have been reported in 84 percent of the 137 patients reported since 1970; 3 percent 
required amputation and 3 percent had cerebral emboli. Because the severe arterial complications 
were primarily the result of delayed therapy, they can best be avoided by early recognition, 
diagnosis, and treatment.

Luoma A, Nelems B. Thoracic outlet syndrome. Thoracic surgery perspective. Neurosurg Clin NA 
1991;2:187-226.
We have attempted throughout this review to identify the issues surrounding thoracic 
outlet syndrome (TOS) as well as to highlight their origins. It should be clear that many aspects 
of TOS remain controversial from the definition of the entity through pathogenesis, diagnosis, 
and treatment. The conflicts surrounding TOS are underlined most poignantly in the many letters 
to the editor of the New England Journal of Medicine in response to Urschel's 1972 publication. 
It is incumbent upon those of us who treat patients with TOS to dispel the ignorance surrounding 
this syndrome with astute, accurate, and reproducible observations. We must clearly define TOS as 
a clinical entity such that we may analyze the characteristics of the patients we treat. We must 
continue to search for innovative and specific diagnostic criteria. We must quantitatively and 
reproducibly measure subjective end points of pain severity and quality of life. The use of these 
methods will provide yardsticks for therapeutic success and act as determinants for the natural 
history of TOS. The objectives of treatment will remain the alleviation of symptoms and the 
restoration of function. We have applied these principles to the formulation of a protocol in 
which we record, in a prospective manner, both routine and innovative clinical parameters. With 
quantification of subjective end points, we may be able to correlate clinical presentation with 
outcome. We also may be able to define with some accuracy this entity we call thoracic outlet 
syndrome.

Sanders RJ. Results of the surgical treatment for thoracic outlet syndrome. Semin Thorac 
Cardiovasc Surg 1996;8:221-8.
Excellent and good results following different operations for thoracic outlet syndrome 
TOS are close to 80%, using simple statistics, where results included many patients followed up 
for only a few months. Using life-table methods, the success rate is 6% to 9% less, close to 70%, 
at 5 years. The results were virtually identical for anterior and middle scalenectomy, 
transaxillary first rib resection, and combined supraclavicular scalenectomy and first rib 
resection. Secondary success, the results of reoperation on patients in whom the first operation 
failed, improved the results of the primary operation 15% and 17%, respectively, for 
transaxillary rib resection and anterior and middle scalenectomy. When the initial operation was 
combined rib resection and scalenectomy, fewer patients underwent reoperation, as only neurolysis 
could be performed, and the results improved only 3%. A significant variable in results was 
etiology: Work-related injuries versus non-work-related accidents, usually auto accidents. 
Results of three independent studies showed better success rates by 13% to 15%, in patients who 
had non-work-related auto accidents, as compared with work- related injuries.

Mackinnon SE, Patterson GA, Novak CB. Thoracic outlet syndrome: A current overview. Semin 
Thorac Cardiovasc Surg 1996;8:176-82.
Thoracic outlet syndrome and the surgery associated with this diagnosis have a 
controversial reputation. The majority of patients with thoracic outlet syndrome seen in the 
context of the work place will have a multiplicity of components to their symptomatology, 
including multilevel nerve compression and muscle imbalance of the neck, shoulder, and back. 
Identification and conservative management of these problems make the necessity for surgery for 
thoracic outlet syndrome a rare event. Decompression of the brachial plexus, with or without 
first rib resection, is a technically demanding surgical procedure requiring expertise in 
peripheral nerve, vascular and thoracic surgery. Evaluation of these patients requires an 
understanding of neuromuscular physiology and chronic pain syndromes.