The Forgotten Pectoralis Minor Syndrome: 100 Operations for Pectoralis Minor Syndrome Alone or Accompanied by Neurogenic Thoracic Outlet Syndrome

Article Outline

• Abstract
• Introduction
• Patient Population and Methods
  • PM Muscle Block
  • Electrodiagnostic Studies
  • Conservative Treatment
  • Patient Selection
  • Operative Technique
  • Statistical Methods
• Results
  • Two Groups
  • Etiology
  • Symptoms
  • Work Status
  • Physical Examination
  • Response to Muscle Blocks
  • Electrodiagnostic Testing
  • Results of Surgery
  • Complications
  • Recurrent Symptoms
• Discussion
  • History
  • Differentiating NPMS From NTOS
  • Choice of Operations
  • Incision and Second ICBCN
  • Fusion of Pectoralis Minor to Pectoralis Major
  • Late PM Tenderness
  • Electrodiagnostic Studies
  • Time of Failure
  • Significance
  • Unexpected Benefit
• Summary
• Acknowledgment
• References
• Copyright

Background

Since 2005 when we became aware of pectoralis minor syndrome (PMS), more than 75% of patients diagnosed with neurogenic thoracic outlet syndrome (NTOS) also have neurogenic PMS (NPMS), and about 30% have only NPMS, without NTOS.

Methods

Diagnosis was made based on history, physical examination, pectoralis minor (PM), and scalene muscle blocks with lidocaine. Pectoralis minor tenotomy was performed as an outpatient procedure under local anesthesia with heavy sedation through a 5-7 cm transaxillary incision.

Results

The clinical picture included pain or tenderness in the anterior chest wall and axilla, together with physical findings of tenderness over the pectoralis minor tendon. Other symptoms were extremity pain, weakness, and paresthesia, similar to symptoms of NTOS. In 76 patients, 100 operations were performed: 48 for NPMS combined with NTOS and 52 for NPMS-alone. Features distinguishing the PM-alone group were fewer and milder occipital headaches, less neck pain, and fewer positive physical findings. Preoperatively, 85% of the of the PM-alone group were still employed compared to only 57% of the combined group (p=0.01). Success rates with 1-3-year follow-up for the PM-alone group were 90% good-excellent, 2% fair, and 8% failed; for the combined group success rates were 35% good-excellent, 19% fair, and 46% failed. All but one of the failures was immediate, only one was late. The only complication was 3 wound infections. Most patients returned to work within a few days. In the combined PMS/TOS group, most of the failed patients subsequently had thoracic outlet operations.

Conclusion

PMS commonly accompanies NTOS and frequently exists alone. Its recognition is important as many patients with suspected NTOS can be treated successfully with a simple, essentially risk-free PM tenotomy. Should this fail, thoracic outlet decompression can always be performed at a later date.

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Introduction 

Pectoralis minor syndrome (PMS) is characterized by pain, paresthesia, weakness, and/or venous or arterial insufficiency produced by compression of the axillary neurovascular bundle by the pectoralis minor (PM) muscle. Although described over 60 years ago, the condition has been ignored by most practitioners. It was brought to our attention a few years ago by Dr. George Thomas of Seattle, and we began to take a better look at this diagnosis in 2005. At that time, we started looking for PM involvement in all patients being seen for thoracic outlet syndrome (TOS) and have been surprised to find that more than 75% of patients with symptoms of neurogenic thoracic outlet syndrome (NTOS) also have neurogenic PMS (NPMS), and many of them have NPMS alone, without NTOS.

In the past 3 years, PM tenotomy (PMT) has been performed in more than 300 patients; in some as the only operation and in others along with thoracic outlet (TO) decompression. This article describes the first 76 patients who received 100 PMTs alone, as a primary operation. It describes the criteria to differentiate PMS from NTOS. In particular, we want to highlight clinical findings that help separate these two groups of patients. This will have a major effect on the management of patients thought to have NTOS.

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Patient Population and Methods 

There were 100 operations in 76 patients: bilateral in 24, unilateral in 52. There were 63 women (83%) and 13 men (17%), aged 15-70 years. Six (7%) were teenagers (5 girls), 14 (28%) were aged 50-62 years, one was 70, and the remaining 55 patients (73%) were between 20 and 50 years of age.

Their medical history included details of etiology and locations of pain and paresthesia. Physical examination revealed tenderness in the neck, chest wall, and axilla, as well as a complete examination for NTOS including all provocative maneuvers.¹

PM Muscle Block 

The most useful diagnostic test was a PM muscle block. This was performed by injecting 4 mL of 1% lidocaine into the PM. The point of injection was determined by locating the most tender spot over the PM about 3 cm below the clavicle. A number 22, 1½ inch needle was inserted at a 45° angle upward to avoid the pleura, aiming toward the coracoid process. The needle was moved continuously during the injection and the syringe constantly aspirated to avoid injecting into the axillary vein or artery. A good response to the block was a significant relief of symptoms that were present at rest for 20-40 minutes as well as improvement of most of the positive findings on physical examination. In patients suspected of having NTOS in addition to NPMS, a scalene muscle block was also performed.²

Electrodiagnostic Studies 

Electrodiagnostic studies were performed on most patients. These included electromyography and nerve conduction velocity tests. Also a relatively new measurement of the sensory medial antebrachial cutaneous (MAC) nerve was performed in several patients.³

Conservative Treatment 

Initial treatment was physical therapy which included posture correction and stretching exercises of the PM muscle by holding the shoulders in a military hyper-abducted position or by stretching into the corner of a wall or into a doorway with hands on the door jams. If successful, no further treatment was needed. If NPMS was associated with NTOS, physical therapy for NTOS was added. Patients whose symptoms did not respond to therapy were offered surgical PMT.

Patient Selection 

Patient selection for surgery was based in part on muscle blocks. Scalene muscle blocks were performed in patients with physical findings that supported the diagnosis of NTOS if the PM block had not relieved most symptoms. Patients who did not have much improvement after the PM block, and who had a good response to the scalene block, were offered TO decompression. If clinically there was PM tenderness and even a little improvement to the PM block, combined TO and PM decompression was performed. These patients are not included in this communication.

If there was a fairly good response to the PM block and more improvement with the scalene block, the patient was offered a choice of either PM decompression alone or combined PM and TO decompression simultaneously. This study includes only those patients with both conditions who elected PM decompression alone.

Operative Technique 

During the first year of this study, general anesthesia was used and the patients hospitalized overnight. After the first year of the study, the operation was performed as an outpatient procedure under local anesthesia with heavy sedation by an anesthesiologist. Only three patients required a general anesthetic since starting the new approach. Most patients were discharged a few hours after surgery, but if patients had nausea or were too uncomfortable they were observed in the hospital overnight.

The patient was positioned supine with a sand bag or towel under the operated shoulder. To expose the axilla, the arm was elevated straight overhead and held by a special pole used by orthopedic surgeons to elevate the arm during shoulder arthroscopy. A 5-7 cm transverse incision was made in the axilla 1 cm above the bottom of the hair line. The incision began anteriorly, near the anterior axillary fold to avoid the second intercostal brachial cutaneous nerve which tends to run in the posterior part of the axilla. The soft subcutaneous fat was divided with a cautery through most, but not all, of the fat. Dissection moved anteriorly with a “peanut” and finger to identify pectoralis major. The lateral edge of pectoralis major was followed deep, until the coracoid process and PM were identified. In a few patients, PM was fused to pectoralis major. In these patients the coracoid process was identified first, and the muscle fibers inserting into the coracoid were separated from the muscle fibers above them. The lower fibers always proved to be PM. PM was isolated and the tendon divided at the coracoid process with a cautery extension. The end of the muscle was elevated with a long clamp, and 2-3 cm of muscle was excised with a cautery, making sure to identify and leave intact any nerve entering the muscle belly, because this could be part of the nerve supply to pectoralis major. The neurovascular bundle was now identified and any bands or ligaments in the clavipectoral fascia that crossed the bundle were divided, including one patient who had a Langer's arch.⁴ The wound was closed with absorbable sutures subcutaneously and subcuticularly.

Postoperatively, the patient was given instructions on a home stretching program that included wall climbing with a goal of obtaining complete extension and abduction of the arm within 2-3 days.

Results were obtained by follow-up examination, questionnaire, or phone interviews. Results were graded excellent, good, fair, or failure. An excellent result was relief of all symptoms, a good result was relief of most major symptoms with some mild residual symptoms, a fair result was partial relief of some symptoms while other major symptoms persisted, and a failure was not enough relief to have made the operation worthwhile.

Statistical Methods 

The Fisher exact test was used to determine statistical differences.

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Results 

Two Groups 

In analyzing the symptoms and physical findings, it was possible to divide patients into two groups, 52 operations for NPMS-alone and 48 operations in patients who had both NPMS and NTOS. Differentiation between the two groups can be seen in Fig. 1, Fig. 2.

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• Fig. 1 

  Symptoms: p values were <0.05 for the first eight symptoms, including “still working.” The p values were >0.05 for the bottom seven, including pain over the trapezius and pectoralis minor as well as paresthesia.

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• Fig. 2 

  Physical findings: All physical findings but one were significantly greater in the combined PMS-TOS group compared with the PM-alone group (p < 0.05). The one exception was that there was no significant difference in tenderness over the pectoralis minor between the two groups (p = 0.119).

Etiology 

Etiology in both groups of patients is listed in Table I with a comparison with patients operated on for NTOS in the 2 prior years. In both the groups, auto accidents and neck injuries were the number one cause, followed by repetitive stress injuries and work injuries. The only difference was a trend—in the NPMS-alone group, there were more patients with athletic and spontaneous etiologies, whereas in patients with combined NTOS and NPMS the patients had more repetitive stress injuries and work injuries. However, these differences were not statistically significant (p > 0.05, Table I).

Table I. Etiology

Symptoms 

Almost all patients in both groups complained of pain or tenderness in the anterior chest wall, usually just below the clavicle or demonstrated tenderness over the pectoralis minor tendon on physical examination. Patients with only NPMS had a significantly lower incidence of occipital headaches, pain in their neck, supraclavicular area, shoulder, arm, and axilla compared with patients with both diagnoses (p = 0.02 to <0.001) (Fig. 1). The incidence of pain in the arm, trapezius and PM as well as paresthesia was not significantly different between the two groups (p = 0.053, 0.16, 0.059, 0.114, respectively). Paresthesia was most common in all five fingers and next most common in the fourth and fifth fingers. This was true in both groups of patients.

Work Status 

The ability to continue working was significantly better in the NPMS-alone group compared with the group with both diagnoses (85% vs. 57%, p = 0.01) (Fig. 1). This correlates with the observation that the severity of pain and disability was significantly greater in the combined group. Patients in both the NPMS-alone group and the combined NPMS and NTOS group had to give up strenuous physical activities and competitive sports.

Physical Examination 

All patients in the combined NPMS and NTOS group had PM tenderness. In the NPMS-alone group, all but four patients had tenderness over the PM tendon. Each of the four patients without tenderness had bilateral symptoms, the milder side lacking PM tenderness. Except for pectoralis minor tenderness, all other areas of tenderness and all provocative maneuvers gave significantly more positive responses in the combined group than the NPMS-alone patients (p = 0.001-0.008) (Fig. 2). In addition, in those PM-alone patients who did respond positively to provocative maneuvers, the intensity of the response was minimal compared to those with both conditions.

Response to Muscle Blocks 

Pectoralis minor muscle blocks in the PM-alone group gave good responses in all but two patients. One had a poor response to surgery. In the group of patients with both NPMS and NTOS, only one patient failed to respond favorably to the PM block and this patient had a poor response to surgery. These three patients were operated on because their clinical pictures were typical of their diagnoses and other therapies had already been tried unsuccessfully.

Scalene muscle blocks were performed on 33 of the 48 patients with both diagnoses. In these patients, the PM block was always performed first. If patients had good to excellent relief of all symptoms and very few positive findings left on physical examination, a scalene block was not done as there were few symptoms left with which to evaluate a scalene block. Among the 33 patients who were blocked, good responses were obtained in all but three.

Electrodiagnostic Testing 

MAC nerve measurements were obtained in 15 patients. Four criteria for a positive response were established earlier.³ These criteria are a latency over 2.4 ms; an increased latency of 0.3 ms or more in the symptomatic side compared with the asymptomatic side; an amplitude ratio of 2.0 or more of the asymptomatic side over the symptomatic one; and an absolute amplitude of <10 microvolts.³ Positive responses were noted in at least one of the four criteria in 14 of the 15 patients. Three patients had one positive criterion, five patients had two, and five had three or four of the four possible positive diagnostic criteria.

Results of Surgery 

Recovery time was short and most patients were back to usual activities within a few days, although there was soreness for 2-4 weeks. For most patients, acetaminophen managed the pain whereas others required mild narcotics. No patient was made worse by the operation. Follow-up time was a minimum of 12 months; the longest follow-up was 3 years. The overall failure rate for PM decompression in all patients was 29%. However, the failure rate in PM-only patients was 8% compared with 46% for patients with both conditions (Table II).

Table II. Results: pectoralis minor tenotomy in patients with and without NTOS

Among the patients with both NPMS and NTOS, 35% experienced good improvement and 19% had only fair improvement. Among the 46% (22 patients) who failed, 13 patients have undergone surgical TO decompression. Short-term follow-up reveals good improvement in 11. Three more are awaiting operations. The other patients with poor results either have other diagnoses accounting for the majority of their symptoms or their symptoms are not severe enough to consider surgical TO decompression. Among the nine patients (19%) with fair improvement, it is expected that some will want to undergo TO decompression in the future as some major symptoms are still present.

Complications 

Three patients had wound infections, which occurred 2-6 weeks postoperatively. They all responded to drainage and antibiotics. These patients did not receive prophylactic antibiotics. (Subsequent to this study, prophylactic antibiotics were started on all patients and no more wound infections have appeared). Two patients experienced temporary paresthesia in the thumb and index fingers. These cleared up without treatment within 4 weeks.

Numbness or paresthesia in the underside of the upper arm occurred in 15% of the patients. This cleared up in the majority of patients within a few weeks but persisted in three patients for a few months. This symptom is the result of injury to the second intercostal brachial cutaneous nerve. In case it persists, the diagnosis can be confirmed by improvement following a lidocaine block and treated by dividing the nerve under local anesthesia by reopening the original incision. Operation to divide this nerve was necessary in one patient.

One late complication has appeared in three patients: tenderness over the PM muscle a few months postoperatively. This has been successfully treated with steroid injections into the tender area.

Recurrent Symptoms 

To date, there have been no cases of recurrent PMS. The immediate failures have been due to a wrong diagnosis; the delayed failures have been due to associated NTOS.

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Discussion 

History 

PMS was first described in 1945 and labeled the hyperabduction syndrome.⁵ Later it acquired the name of subcoracoid syndrome. Initially it was regarded as an arterial compression phenomenon and was seldom treated. Subsequently, it was realized that this muscle can compress nerve branches of the brachial plexus⁶, ⁷, ⁸, ⁹, ¹⁰ as well as the axillary vein¹¹ or axillary artery.¹² Other than these occasional reports, very little literature has been published on the subject of PMS. In 2004, PMT was reborn in Seattle where it was added to operations for recurrent NTOS in 13 patients.¹³ It was about this time that we saw a patient who complained of severe chest pain a few months after TO decompression. He was very tender over the PM tendon and a PM block gave him dramatic relief. His arm had been limited to 45° abduction before the block; after the block it improved to 180°. This experience convinced us to pay more attention to PMS.

Differentiating NPMS From NTOS 

Diagnosis of NPMS requires the same history and physical examination that is necessary for NTOS patients. However, there are some differences. Similar to NTOS patients, those with NPMS-alone often have a history of trauma before the onset of symptoms. However, more patients with NPMS-alone have a history of spontaneous onset. When there is no history of trauma, one should carefully consider NPMS when evaluating for NTOS.

Criteria for the diagnosis of NPMS-alone vary. Patients have some of the symptoms of NTOS, with particular emphasis on chest pain, trapezius pain, and/or hand paresthesia. Few have significant occipital headaches and neck pain. When these symptoms are present, they are usually intermittent and not a major complaint. In contrast, patients with NTOS have significant symptoms in the head and neck, and often these symptoms predominate.

In NPMS-alone patients, physical examination usually lacks vigorous responses and often shows minimal or no response to the provocative maneuvers of neck rotation and head tilt that are seen in NTOS. The same is true for the ULTT and duplications of symptoms with the 90^°abduction in external rotation (AER) position which usually are positive but with mild intensity. Furthermore, when scalene muscle tenderness is present in NPMS-alone patients it is usually mild.

Muscle blocks are very helpful in confirming a diagnosis. A good response to the PM muscle block is an almost essential requirement for the diagnosis of NPMS. In the present study, putting together all the patients of both groups, a total of three patients had poor responses to the PM block; only one patient improved after surgery. In these three patients, surgery was offered because each had symptoms compatible with NPMS and all other therapy had been tried and failed. In general, patients who fail to improve after the PM block are poor candidates for PM decompression.

Choice of Operations 

In patients who have both NPMS and NTOS, a double crush syndrome,¹⁴ there is a choice of operations between PM decompression alone or combined PM and TO decompression performed simultaneously. Although this report deals only with primary operations, the choice is the same for patients with recurrent NTOS.

When reviewing separately the clinical features in the combined group of this study, there was no significant combination of findings to help differentiate the successes from the failures. From this study it can be stated that a patient with combined NPMS and NTOS who experiences good improvement after the PM block has just a 35% chance of a good result from PM release alone, thereby avoiding the bigger operation of TO decompression. In case PM decompression fails, TO decompression can always be performed at a later date as occurred in the majority of the patients who did not improve after PMT. In view of the low success rate, patients with both diagnoses should be advised that they have the option of having both areas operated upon simultaneously. Since the completion of this study, most patients are opting for the combined operation.

In our experiences with recurrent NTOS in patients who exhibit findings of NPMS, performing PM decompression as a solo, low-risk procedure is worth trying before attempting reoperation in a scarred area. Our results in patients with recurrent NTOS will be the subject of a future communication, but it can be noted here that early results with just PM release in patients with recurrent NTOS are very encouraging.

Incision and Second ICBCN 

Because the second intercostal brachial cutaneous nerve runs through the axilla, incisions in this area frequently cut or stretch this nerve. Stretching or partially cutting the nerve is worse than totally transecting it. Total transection leaves a numb area on the underside of the upper arm which is not painful, and patients are able to tolerate it easily. The stretched or partially transected nerve can cause burning pain in the upper arm which can be very uncomfortable. This is treated with Neurontin (generic Gabapentin) or Lyrica. If symptoms do not subside, the incision can be explored and the nerve completely transected. Conversion to numbness will solve the problem.

Other than the transaxillary incision, other equally effective approaches are through a vertical incision along the anterior axillary fold or an infraclavicular incision which separates the pectoralis major by separating its muscle fibers. The advantage of the transaxillary approach is that it hides the incision and this is preferred by many women. The 5-7 cm length of incision could be made shorter as experience is gained. However, getting much shorter might make exposure of the coracoid process difficult. The procedure could be performed endoscopically, although this would probably incur more expense and operating time.

Fusion of Pectoralis Minor to Pectoralis Major 

In a few patients, the PM is difficult to identify because its muscle fibers are fused with pectoralis major. This is managed by first identifying the coracoid process. Only the muscle fibers inserting on the bone are PM. By developing a dissection plane at the top of the coracoid, separation between the two muscles can be accomplished. We have found that spreading the muscle with the back of a scissors, parallel to the fibers at the top of the coracoid, will usually find an avascular plane between the two muscles. If the plane is not avascular, dissection should be stopped and another plane looked for until the avascular one is found.

Late PM Tenderness 

A few patients have chest wall tenderness over the end of the divided PM muscle several months after surgery. This is probably because the end of the muscle has not fixed to the chest wall and is still inflamed. This can result because of too much vigorous activity of the shoulder during the first several postoperative weeks and is treated by injecting steroid into the tender area. The patient should then avoid vigorous activity with that arm for the next few months.

Electrodiagnostic Studies 

Near the end of this study, measurement of MAC nerves was instituted. This proved helpful in confirming the clinical diagnosis with objective testing. Although only 15 patients had the benefit of this test, it revealed abnormalities in 14. This test appears to have better sensitivity and specificity than any other objective test currently available to support a diagnosis of NPMS as well as NTOS.

Time of Failure 

All failures after solo PMT were apparent within the first few weeks after surgery. The reason is that the nerves of the brachial plexus are not lysed of all bands and scar tissue as is done in TO decompression by either supraclavicular or transaxillary approaches. When the plexus is dissected, recurrence can occur up to 24 months postoperatively as a result of scar tissue building up around the nerve roots. We have not seen this after solo PMT.

Significance 

Learning to recognize PMS as a distinct entity has had a significant effect on our treatment of TOS. In 2004, the first 100 operations performed for patients with symptoms of NTOS were all TO decompression procedures. In 2007, after differentiation between NPMS and NTOS was recognized, only 46 of the first 100 operations were TO decompression and 33 of these included PM decompression as well. The other 54 operations were PM decompression alone–a procedure with significantly less morbidity and a much shorter recovery time than TOS decompression.

Unexpected Benefit 

When performing transaxillary first rib resection for either neurogenic or venous TOS, it had always been our practice to preserve the PM muscle by retracting it. However, because our experience with dividing the PM muscle as therapy has shown no detrimental shoulder impairment as others have noted,¹⁵ PMT is now added to all transaxillary approaches. It makes retraction easier and enhances exposure.

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Summary 

NPMS should be considered in all patients being evaluated for NTOS. It can be recognized by symptoms of pain or tenderness in the anterior chest wall and axilla plus physical findings of tenderness over the pectoralis minor tendon. Patients also have extremity symptoms of pain and paresthesia. It can exist alone or as a “double crush” condition along with NTOS. Diagnosis can be confirmed by a positive response to a PM muscle block. Initial treatment is stretching exercises of the PM. If this fails, PMT has proven to be essentially a risk-free procedure with a high success rate. Recognition of PMS as a distinct entity will have a significant positive effect on the management of patients initially diagnosed with NTOS.

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The authors thank Dr. Ben Eiseman for his counsel and Sara Thorne of the medical staff office of Rose Medical Center for her assistance in preparing the figures for this manuscript.

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References 

1. Sanders RJ, Hammond SL. Diagnosis of thoracic outlet syndrome. J Vasc Surg. 2007;46:601–604
   • View In Article
   • Abstract
   • Full Text
   • Full-Text PDF (178 KB)
   • CrossRef
2. Sanders RJ, Haug CE. Thoracic Outlet Syndrome. A Common Sequela of Neck Injuries. Philadelphia, PA: Lipppincott; 1991;p 91
   • View In Article
3. Machanic BI, Sanders RJ. Medial antebrachial cutaneous nerve measurements to diagnose neurogenic thoracic outlet syndrome. Ann Vasc Surg. 2008;22:248–254
   • View In Article
   • Abstract
   • Full Text
   • Full-Text PDF (504 KB)
   • CrossRef
4. Sachatello CR. The axillopectoral muscle (Langer's axillary arch): a cause of axillary vein obstruction. Surgery. 1977;81:610–612
   • View In Article
   • MEDLINE
5. Wright IS. The neurovascular syndrome produced by hyperabduction of the arms: the immediate changes produced in 150 normal controls, and the effects on same persons of prolonged hyperabduction of the arms, as in sleeping, and in certain occupations. Am Heart J. 1945;29:1–19
   • View In Article
   • CrossRef
6. Lord JW, Stone PW. Pectoralis minor tenotomy and anterior scalenotomy with special reference to the hyperabduction syndrome and “effort thrombosis” of the subclavian vein. Circulation. 1956;13:537–542
   • View In Article
   • MEDLINE
7. d'Huart . A propos de six case de syndrome du scalene anterieur traites par scalenotomie et section du petit pectoral. Ann Chir. 1964;18:205–209
   • View In Article
   • MEDLINE
8. McIntyre DI. Subcoracoid neurovascular entrapment. Clin Orthop Relat Res. 1975;108:27–30
   • View In Article
   • CrossRef
9. Stallworth JM, Quinn GJ, Aiken AF. Is first rib resection necessary for relief of thoracic outlet syndrome. Ann Surg. 1977;185:581–592
   • View In Article
   • MEDLINE
   • CrossRef
10. Stallworth JM, Horne JB. Diagnosis and management of thoracic outlet syndrome. Arch Surg. 1984;119:1149–1151
    • View In Article
    • MEDLINE
11. Sanders RJ, Rao NM. Pectoralis minor obstruction of the axillary vein: report of six patients. J Vasc Surg. 2007;45:1206–1211
    • View In Article
    • Abstract
    • Full Text
    • Full-Text PDF (699 KB)
    • CrossRef
12. Finkelstein JA, Johnson KW. Thrombosis of the axillary artery secondary to compression by the pectoralis minor muscle. Ann Vasc Surg. 1993;7:287–290
    • View In Article
    • Abstract
    • Full-Text PDF (355 KB)
    • CrossRef
13. Ambrad-Chalela E, Thomas GI, Johansen KH. Recurrent neurogenic thoracic outlet syndrome. Am J Surg. 2004;187:505–510
    • View In Article
    • Abstract
    • Full Text
    • Full-Text PDF (59 KB)
    • CrossRef
14. Upton AR, McComas AJ. The double crush in nerve-entrapment syndromes. Lancet. 1973;2:359–362
    • View In Article
    • CrossRef
15. Scevola S, Cowan J, Harrison DH. Does the removal of pectoralis minor impair the function of pectoralis major?. Muscle Nerve. 1999;11:1597–1599
    • View In Article