Thoracic Outlet Syndrome

A 44-year-old woman presents with a chief complaint of neck pain with radiation of paresthesias into her left medial forearm, and fourth and fifth digits. She was involved in a rear end motor vehicle collision 2 years prior. Her symptoms are exacerbated by work (eg, typing, mousing), and combing her hair, and have remained relatively constant at 3 of 10 average, and 8 of 10 at its worst by visual analogue scale (VAS) scale. Her current physical examination reveals a moderate cervicothoracic kyphosis, head forward, rounded shoulder posture. She has a normal neurologic examination with absence of extremity edema, normal pulses, and no bruits with auscultation over the supraclavicular fossae. Spurling maneuver recreates local pain into the upper trapezius only. Roos, Wright, and Adson tests are positive bilaterally for reproduction of her medial forearm and digit paresthesias without diminished pulses. Cervical radiographs reveal elongated C7 transverse processes bilaterally without cervical ribs and magnetic resonance imaging 6 months after the injury showed mild to moderate spondylosis at C5-6 and C6-7 without central or foraminal stenosis. A Doppler ultrasound study performed 8 months after the injury was negative for upper extremity deep vein thrombosis and an electrodiagnostic test 8 months after the injury was negative for radiculopathy, plexopathy, or ulnar entrapment neuropathy. Treatment has included 3 months of chiropractic and 12 visits of physical therapy immediately after the accident including ultrasound, massage, electricl stimulation, and cervical traction, with each treatment offering only mild temporary relief. In total, her presentation is suggestive for thoracic outlet syndrome, but there is no distinct evidence for neurological or vascular impairments. Her primary care provider has suggested that this problem may be “in her head.” What is your clinical impression and what further assessment and treatment do you recommend? This case describes a typical patient often encountered several months or even years after blunt trauma to the cervicobrachial region and presents both a diagnostic and treatment dilemma for practitioners. As a vascular surgeon with a clinical research interest in the treatment of athletic vascular injuries, I am faced with these types of posttraumatic cases, as well as work-related overuse injury and repetitive motion athletic injury. These patients often are referred with the request to “rule out thoracic outlet syndrome.” Thoracic outlet syndrome (TOS) is a poorly characterized disease entity with a wide differential diagnosis. First coined in 1956 by Peet et al [1], TOS can be categorized as vascular (arterial or venous) or neurogenic (NTOS). Although vascular-related TOS pathology is intuitively easier to understand and document because of more definitive imaging findings and symptoms, there remains significant controversy as to even the existence of NTOS [2, 3]. The anatomic issue in TOS occurs as the result of compression of the neurovascular bundle (brachial plexus, subclavian artery, and subclavian vein) at the transition between the neck and axilla just above the first rib. Neurogenic TOS is much more common than vascular TOS, with most single-center series reporting ratios of 20 to 1. Symptoms of NTOS referable to the upper extremity occur because of compression of the lower trunk of the brachial plexus caused by a cervical rib or band and enlarged scalene muscles. Classically described or “true” NTOS with strict diagnostic criteria was outlined by Gilliatt et al in 1970 [4], but unfortunately, most reported series of NTOS to date rarely meet these criteria. Symptoms typically include arm discomfort, paresthesias of the inner surface of the hand and forearm, and weakness and atrophy of the thenar and intrinsic hand muscles of the affected side. Distinct anatomic and electrophysiologic findings include low compound muscle action potentials in the thenar and intrinsic muscles, abnormal sensory conduction of the ulnar nerve, prolonged F-wave latency of the ulnar nerve, and abnormal sensory conduction of the medial antebrachial cutaneous nerve. Because these criteria rarely are documented in most patients referred for NTOS, Wilbourn [3] introduced the phrase “disputed” or nonspecific NTOS (NNTOS), which I believe our patient in this discussion falls under. I submit that surgical treatment of vascular TOS and “true” NTOS via thoracic outlet decompression is generally well accepted and indicated, but what remains controversial is the 90% of cases that are TOS. The controversy in the diagnostic workup for patients with suspected NNTOS emanates from the fact that the presentation can be varied and overlaps with many other musculoskeletal issues of the upper extremities. Patients will typically have a history of a hyperextension neck injury, such as whiplash from an automobile accident or a fall to the floor. Also very common is a work-related injury caused by repetitive movements [5]. Predisposing anatomic factors to NNTOS include cervical ribs, anomalous first ribs, and congenitally narrowed scalene triangles. Another common presentation is athletes with repetitive upper limb movements, including swimmers, divers, water polo players, rowers, baseball pitchers, and football quarterbacks [6]. Certainly, this very heterogeneous group of presenting patients will have a wide differential diagnosis, including and not limited to cubital and carpal tunnel syndromes, myofascial pain syndromes, and spinal stenosis [7]. The evaluation when considering NNTOS begins with a thorough history and physical examination, with the clinician attempting to elicit the exact nature of discomfort, paresthesias, and disability in the patient. An accurate physical examination documents whether certain nerves or nerve roots are involved. I find the Roos and Adson tests particularly helpful because the provocative positioning eliciting symptomatology or a change in the pulse can be quite reproducible. The combination of any of the maneuvers that bring about symptoms or pulse dropouts are not very sensitive but can be quite specific in that not having any positive signs makes it unlikely that NNTOS is the correct diagnosis. For our patient in question, she fits the typical profile, having experienced a whiplash injury several years ago and now has had years of vague upper extremity symptoms. Her physical examination showed some reproduction of symptoms with provocative maneuvers and no other obvious physical abnormalities. Often overlooked and poorly documented in the literature is how these types of diseases disable people from activities of daily living. Although we may ask and even write in the chart spontaneous comments about patients' limitations, the lack of a validated and objective measure makes follow-up and comparisons difficult. Some very promising work uses standardized quality-of-life questionnaires, notably the QuickDASH (Disabilities of the Arm, Shoulder, and Hand) outcome measure, which generates a score that ranges from 0 to 100, with 100 indicating maximal disability, and that was initially developed and ultimately validated for upper extremity orthopedic pathologies and their surgical treatments [8]. The Johns Hopkins vascular group has applied this outcome measure to their large series of patients after thoracic outlet decompression of all types and found that the score correlates well with Short Form-36 surveys (which measure general health-related quality of life) and documents significant improvement after surgery [9]. I have been prospectively collecting QuickDASH data on all patients with NTOS during the past 4 years on more than 100 patients, with approximately one half of the patients undergoing surgery mostly for neurogenic reasons. Our long-term goal with this project is to identify predictors of a positive response to surgery. After the initial consultation, inventory of symptoms, accurate physical examination, and completion of the baseline QuickDASH survey, a multitude of radiographic tests can be ordered. Many patients in a referral practice have already had magnetic resonance imaging or computed tomography-angiography of the shoulder because these patients are seen first to rule out musculoskeletal tears or neck pathology. Again, to reiterate the lack of sensitive radiographic findings for NNTOS, the findings often are negative, as in this example. Duplex imaging of the upper extremity is useful in assuring there is no venous component present and is quite sensitive and specific for arterial or venous involvement. Our patient in question here had normal results of a duplex ultrasound. I order for all TOS patients arterial digit plethysmography, which can document with provocative maneuvers the obliteration of waveforms suggestive of a narrowed thoracic outlet. This information can be useful when taken in the context of the entire diagnostic evaluation. At this point in our case, I would consider that conservative management is a safe and appropriate approach. In fact, Landry et al [10] described no significant symptom difference at 4 years after evaluation for NTOS in patients undergoing surgical treatment versus observational therapy. The University of California, Los Angeles vascular surgery group, who has taken an aggressive approach to surgical management, has documented somewhat high long-term failure rates with surgery for NTOS, with only about one half of patients after surgery who showed sustained improvement 18 months postoperatively [7]. Subset analysis in these series and others have found poor predictors of long-term success to include worker's compensation cases [11], duration of symptoms >2 years, and previous operations. Given the unknown long-term issues with such a surgical approach, I concede that initially this patient should undergo a 2- to 3-month trial of conservative management on the basis of comprehensive physical therapy. I prefer the TOS-specific algorithms described by Edgelow [12]. Conservative measures also include relaxation/stretching exercises, biofeedback, muscle relaxants, analgesics, and antiinflammatory medications. The Edgelow protocol focuses on breathing, relaxation, posture, and positioning to relieve stress on the narrowed thoracic outlet. Different protocols have been described that try to alleviate strain imparted to the neck region. Upon returning for consultation after 3 months of conservative treatment, I would verify that the patient completed a satisfactory number of physical therapy visits. The number of visits to physical therapy often ranges from 2 visits total to 2 visits per week for the previous 12 weeks. Because I believe part of the success of surgical intervention relies upon postoperative physical therapy, commitment to the program preoperatively might indicate the patient's willingness to continue with physical therapy after surgery and maximize the likelihood of an improved outcome. At this 3-month follow-up visit, the patient repeats the QuickDASH survey, and the next step in therapy is based on improvement in score as well as the patient's subjective feelings. My protocol for deciding who should be offered surgery is influenced by those that improve on their physical therapy regimen by a documented decrease in their QuickDASH disability score. With more patients enrolled in this prospective protocol and longer follow-up, I hope to better delineate which patients to recommend for surgery. The lack of guidelines in the literature on who is the best surgical candidate makes decisions about treatment difficult and sometimes frustrating for patients and practitioners. Objective data related to surgical treatment of NNTOS are not available for the success of surgical therapy, long-term sustainable outcomes, and predictors of success or failure. When I do offer surgery, my approach is the standard supraclavicular approach. Once through the platysma muscle, the clavicular head of the sternocleidomastoid muscle is transected. The anterior scalene fat pad is reflected superiorly, revealing the anterior scalene muscle and the phrenic nerve, which must be preserved and protected with a vessel loupe. The lymphatic ducts are carefully identified and suture ligated or cauterized with the aid of bipolar scissors. The anterior scalene muscle is released from the anterior surface of the first rib. The subclavian artery is identified, freed, and also encircled with a vessel loupe. This step usually requires division of some side branches, including the thyrocervical trunk, to allow free mobilization of the artery. More laterally, the brachial plexus is identified. Many times, interdigitating fibers of the middle scalene weave their way through this area, which to the pathology. a cervical band the brachial of the a and part of the first rib is particularly the brachial A is to and the brachial plexus, with the thoracic nerve in the most sometimes The rib is from the the middle scalene fibers are taken and the rib is taken immediately the subclavian and vein A with a in the accurate of the and the is after for or lymphatic after the rib is This supraclavicular approach anatomic of the in question and is approximately to on the of the rib the muscle and The patient is on the postoperative after a has been performed in the therapy, particularly exercises, is immediately after surgery, and the patient typically the is in 2 to 3 for a and in 6 to 8 for a symptom inventory and QuickDASH visits are often at 6 months and In the of NNTOS is Many other musculoskeletal and orthopedic to be and patients to understand that surgical are poorly reported without standardized surgery when performed by an experienced surgeon is safe and will rarely symptoms The of surgery for NNTOS is the patients who will have significant My current for surgical treatment of NNTOS the of appropriate findings on history and physical examination, of obliteration of waveforms on arterial duplex that the thoracic outlet is a high baseline QuickDASH a sustained on the patient's part to undergo TOS-specific physical therapy for 2 to 3 and improvement after physical therapy documented and by improvement in the QuickDASH score. the next several years, I hope that this approach to surgery for patients with NNTOS will a standardized that can patients and in their decisions about treatment for neurogenic thoracic outlet As a in a I will my the treatment of this case of thoracic outlet syndrome TOS remains a controversial after its initial in and the of the in 1956 vascular TOS (arterial and venous) documented by appropriate clinical and imaging findings is most with surgery, the surgical approach is neurogenic TOS also requires objective clinical neurologic and electrodiagnostic These are cases, often with rib and should also be for surgical is that even these more of TOS are not identified Patients with TOS are seen by an of appropriate conservative measures are and by surgery is performed The patient described in this case has vascular neurogenic TOS. she presents with a of symptoms that are quite common and suggestive for an in and the anatomic of the thoracic outlet. the Some have suggested that the for clinical to this In my the as coined by Wilbourn should be from this because it that symptoms without should not but in fact, that is the most common presentation in the TOS TOS is the that should be when symptoms of TOS but no neurovascular is Although Wilbourn offered the nonspecific TOS as an to TOS, this to in the literature approximately a ago The of this is related to a distinct that results in of or the thoracic outlet and should be A and clinical assessment of these will a for the and of that is to this The that is with nonspecific TOS is as the posture. This is generally with and myofascial about the neck and shoulder that to and The include thoracic and of the upper thoracic and lower cervical spinal of the anterior neck and and weakness of the cervical upper thoracic and muscles. A common of the head is that it results in a cervical it results in of the cervical is only the upper cervical spinal that the of further and in the already anterior myofascial The and and first rib to the TOS symptoms without the of rib or The patient to have the of nonspecific TOS. In to a maneuvers can be including the Roos, Wright, and the supraclavicular of these maneuvers in arterial but can also be to neurologic symptoms by compression of the lower trunk of the brachial when for neurologic symptom these tests have poor In one prospective case series of patients, the of 4 positive maneuvers to a of and of only [6]. is to that the absence of positive findings with any or all of these signs should not the further A of the patient's program should be for and Patients should be to their program and how This patient has chiropractic therapy and during physical therapy. she presents with a head posture. In this case, the of conservative management is a failure of therapy. physical therapy and should be any discussion of surgery is the history of symptoms. are no series in which the surgical and outcome for nonspecific TOS. and for neurogenic TOS are the basis of the my initial is to physical therapy with specific as by and therapy to with deep massage, point and of the and to the upper cervical and upper thoracic to with the upper cervical hyperextension and the upper thoracic and of the thoracic and trunk The of one study patients who had conservative management and showed a significant improvement in patients who a therapy I would also order an evaluation and request her to from Cervical ribs are present in than of the general and are as a in neurogenic TOS cases These are not typically a in nonspecific TOS. The magnetic resonance imaging findings are not with the of her upper limb symptoms, and further treatment of the cervical with not electrodiagnostic has been to “rule nonspecific TOS. The of electrodiagnostic in for more common of upper limb paresthesias, including ulnar neuropathy. a thorough assessment should include medial and antebrachial cutaneous nerve and with to the side as well as a thorough to the and muscles of the of the and [10] reported that the medial antebrachial cutaneous nerve study was a useful to mild lower trunk a group of patients to normal latency and found that latency had a of and a of The likelihood of findings diagnostic of is to be per and potentials may point to a but lack in the absence of other should be The results of potentials are positive in only of nonspecific TOS patients [12]. are not because large and are to The described by and an local point into the anterior scalene In a case series of patients, the clinical of nonspecific TOS was with a positive arm stress test and over the scalene patients a local and on to surgery. The results that of the surgical patients with a positive response to the had postoperatively The local has not been as a diagnostic for nonspecific TOS. I would not order this in this case because it not to the diagnostic or treatment In case series by et al patients with in the trapezius anterior scalene and middle scalene muscles. patients with physical therapy, pain and was as of symptoms. This combination of and conservative therapy better results at follow-up than local and duration of was A number of patients patients surgery. about as long-term therapy for nonspecific TOS be the of in the trapezius muscle may to that the trapezius muscle is not a primary to TOS. Although I would not this in this case because it has not been to be of long-term and not the of the symptoms. The surgical literature of large case series based on the of several outcome measures and of A of these series that the results with results in from to of patients These results should be with case series found no difference in symptoms, or to work of surgical or in a of nonspecific TOS patients A of worker's compensation cases including both vascular and neurogenic TOS found that patients 3 to 4 more to be than patients Another study found only of patients with nonspecific to activities after surgery the of anatomic had no on trauma was with found that no a high of patients reported that would the surgery Patients with entrapment present with sensory electrodiagnostic and but this is not in cases of nonspecific TOS. This further that nonspecific TOS is a distinct entity and not a mild neurogenic TOS. I would not this patient for surgery on the basis of the case and the available literature on the Her best for in the and issues that have caused her symptoms to I the between Roos and Wilbourn more than 10 years ago in and At that the issue whether nonspecific neurogenic thoracic outlet syndrome even with Wilbourn that NNTOS is more than in and by in a of compensation and injury Although NNTOS is a controversial the to have in our discussion no longer to be the existence of on the appropriate there are of patients who present with paresthesias, and weakness of the upper who do not have imaging or electrodiagnostic evidence for a cervical radiculopathy, nerve or other evidence of brachial In many of these patients, we factors for NNTOS, as described by Edgelow including poor to strain of the of the in on the scalene muscles, of the first and of the thoracic outlet and for nerve and vascular on one often with of the In those patients who do not to at several months of comprehensive physical therapy that these I that further is for that may be the include cervical ribs, abnormal first thoracic ribs, scalene muscle or abnormal of the to a thoracic outlet surgeon as who is experienced in these cases, is in my a when you can that surgery will only be there is a high likelihood of In those patients with a history of such as the case there may be that are difficult to plexus and of anomalous or scalene muscles, and even change of muscle in scalene muscles may be found only with surgical is we more definitive diagnostic to we are not more cases of vascular or neurogenic TOS. The work by with duplex arterial digit promising a test for arterial the study by and in which a combination of medial antebrachial cutaneous latency and with nerve stimulation, to be more sensitive for those cases of neurogenic further research will even better diagnostic and treatment algorithms for those neurovascular I believe most can now that the of cases that we as nonspecific TOS from and it would most appropriate to to this syndrome as the and to these TOS cases will allow other and most our patients, to the and of physical