Thoracic outlet syndrome: a review

To resect or avulse first rib in management of neurogenic thoracic outlet syndrome: a randomized controlled trial

INTRODUCTION

Neurogenic thoracic outlet syndrome (nTOS) is commonly treated with first-rib resection, a procedure linked to postoperative complications, but its necessity remains debated among experts, highlighting the need for further research. This randomized controlled trial aims to compare conventional first-rib resection with the avulsion method to identify the most effective surgical approach.

METHODS

This single-center, randomized, group-sequential trial compared two surgical approaches for treating nTOS. Participants were randomly assigned to undergo first-rib resection (Group A) or first-rib avulsion (Group B), with both groups blinded to treatment allocation. The University of Sulaimani granted ethical approval and obtained written informed consent. Inclusion criteria included nTOS patients requiring surgery, excluding those with other TOS types, cervical ribs, clavicular fractures, or other complications. Outcome measures included pain scores, numbness, and patient satisfaction at multiple time points. Statistical analysis was performed using SPSS and Microsoft Excel.

RESULTS

A total of 48 female patients were enrolled (23 in Group A, 25 in Group B). The mean age was 32.58 ± 7.23 years, and the average operation duration was 48.27 ± 13.95 min. Group B had significantly longer ribs (P < 0.001). Both groups showed significant pain and numbness reduction, with no significant differences in outcomes (P = 0.647, P = 0.839). At 6 months, 92.0% of Group B and 87.0% of Group A patients recommended the surgery.

CONCLUSION

Although statistically not significant, first rib avulsion may offer a viable alternative to resection for nTOS, providing comparable pain relief and functional recovery with reduced invasiveness.

Brachial and Lumbosacral Plexopathies

The brachial and lumbosacral plexuses are complex neural structures that transmit sensory, motor, and autonomic information between the spinal cord and the extremities. Plexus disorders can be particularly disabling because lesions in the plexus usually affect large groups of nerve fibers originating from several spinal levels. Electrodiagnostic studies are often required to confirm a plexus lesion and determine the extent of injury and prognosis. Magnetic resonance is the imaging modality of choice for detecting intrinsic nerve abnormalities; recently, high-resolution ultrasound has emerged as an alternative method for dynamic evaluation and visualization of internal nerve architecture. Once a plexopathy is confirmed, the list of possible etiologies is relatively limited and includes traumatic and nontraumatic causes. Treatment relies on symptom management and physical rehabilitation unless a treatable underlying condition is found. Surgical approaches, including nerve grafts or tendon transfers, may improve limb function when spontaneous recovery is suboptimal.

Regional Anesthesia with Spontaneous Breathing for Trans-Axillary Surgery in Thoracic Outlet Syndrome: A Retrospective Comparative Study

Background: Thoracic outlet syndrome (TOS) is an uncommon condition defined by the compression of neurovascular structures within the thoracic outlet. When conservative management strategies fail to alleviate symptoms, surgical decompression becomes necessary. The purpose of this study is to evaluate and compare the efficacy and safety of regional anesthesia (RA) using spontaneous breathing in contrast to general anesthesia (GA) for patients undergoing surgical intervention for TOS. Methods: We conducted a retrospective comparative study involving 68 patients who underwent trans-axillary first rib resection for TOS. The patient cohort was divided into two groups: 29 patients in the GA group and 39 patients in the RA group. The RA technique employed consisted of supraclavicular brachial plexus (SBP) and pectoral nerve (PECS II) blocks, accompanied by deep sedation. Key outcome measures such as pain scores, opioid consumption, and various perioperative parameters were systematically analyzed. Results: Postoperative pain levels recorded in the recovery room were significantly lower in the RA group, with a median numerical rating scale (NRS) score of zero compared to two in the GA group (p = 0.0443). Additionally, both intraoperative and postoperative opioid consumption showed a marked reduction in the RA group, with p-values of less than 0.001 and 0.0418, respectively. The RA approach was associated with shorter surgical durations (p = 0.0008), a decrease in the incidence of postoperative nausea and vomiting (PONV) (p = 0.0312), and a lower occurrence of intraoperative lung injuries (p < 0.0001). Furthermore, the length of hospital stay was significantly reduced for patients in the RA group. Conclusions: Although both groups reported low postoperative pain scores, the regional anesthesia approach exhibited distinct advantages in terms of opioid consumption, surgical duration, and overall perioperative outcomes. The utilization of SBP and PECS II blocks facilitated surgical procedures and mitigated complications, thereby positively influencing the postoperative recovery trajectory. Future prospective studies are essential to validate these findings further and to investigate long-term outcomes associated with the use of regional anesthesia in TOS surgery.

Arthroscopic Pectoralis Minor Release and Infraclavicular Brachial Plexus Decompression for Neurogenic Thoracic Outlet Syndrome: A Novel Treatment for an Old Problem

Background

Neurogenic thoracic outlet syndrome (nTOS) of infraclavicular etiology is a complex condition involving the compression of the brachial plexus through the interscalene triangle and costoclavicular, infraclavicular, and pectoralis minor space. New insight into nTOS of infraclavicular etiology and its association with scapular dyskinesia has enabled minimally invasive treatments: endoscopic pectoralis minor release (PMR) and infraclavicular brachial plexus neurolysis. The purpose of this study was to analyze clinical outcomes of this technique compared with historically published outcomes for open first rib resection (FRR) and/or scalenectomy.

Methods

All patients who underwent endoscopic surgical decompression for nTOS of infraclavicular etiology were retrospectively reviewed at a single institution. Surgical treatment included endoscopic PMR, subclavius release, and neurolysis of the infraclavicular brachial plexus. Patient-reported outcomes were collected prospectively and compared with prior research on FRR and scalenectomy. A subgroup analysis was performed on patients with prior open FRR or anterior cervical discectomy and fusion (ACDF).

Results

Fifty-eight shoulders among 55 patients were included, with an average follow-up of 25.8 months (range: 12-52). Patients showed significant improvement in visual analog scale pain (7.0-2.1) and single alpha-numeric evaluation scores (37% to 84%). Overall, 90% of patients experienced good or excellent outcomes according to the Derkash classification. There were no major complications and only 2 minor ones (one wound infection and one case of adhesive capsulitis). Satisfaction and Derkash scores among patients undergoing endoscopic surgery were comparable with previously published studies on open FRR and scalenectomy, with lower rates of major complications and equivalent or improved clinical outcomes. Patients with prior ACDF or open FRR had worse postoperative American Shoulder and Elbow Surgeons; Quick Disabilities of the Arm, Shoulder, and Hand; and Derkash scores than the subgroup with no prior intervention.

Conclusions

Endoscopic PMR and infraclavicular brachial plexus decompression is a viable and effective treatment option for nTOS of infraclavicular etiology driven by the pectoralis minor and associated scapular girdle dyskinesia. This cohort demonstrates improvements in clinical outcomes comparable with open scalenectomy and FRR with high patient satisfaction and no major neurologic, vascular, or thoracic complications.

Level of Evidence

Therapeutic Level IV-Case Series. See Instructions for Authors for a complete description of levels of evidence.

Segmental Megaesophagus Secondary to Extraluminal Esophageal Stenosis Caused by Transitional Seventh Cervical Vertebra and Supernumerary Ribs in a Goat

A 4-year-old Nigerian Dwarf wether presented for chronic regurgitation and cervical swelling of three years duration. Physical examination revealed a large ventral cervical mass. The goat made repeated attempts to swallow and regurgitate, but the mass did not change significantly in size. Cervical radiographs revealed segmental esophageal dilation to the level of the thoracic inlet. CT revealed a transitional seventh cervical vertebra with fused right and left ribs, resulting in extramural esophageal compression and obstruction at the level of the thoracic inlet. This is the first report of a cervical rib causing megaesophagus in a goat.

Magnetic resonance neurography in the diagnosis of neurological subtypes of thoracic outlet syndrome

Neurological thoracic outlet syndrome (TOS) can be challenging to diagnose, particularly given its described subtypes of neurogenic TOS (NTOS) and disputed TOS (DTOS) that exhibit variable clinical presentations and etiologies. The diagnostic workup of TOS often includes magnetic resonance neurography (MRN) of the brachial plexus. Specific MRN imaging modifications for TOS evaluation are required to maximize spatial and contrast resolution to increase the conspicuity of nerve segments and their relationships to surrounding osseous structures. Dynamic assessment with arm positioning is used to evaluate outlet narrowing and compression of the plexus. Individual nerve segments are interrogated for their longitudinal and cross-sectional morphologies and signal characteristics. In patients with NTOS, MRN may reveal focal impingement of the C8/T1 nerve roots and/or lower trunk with accompanying abnormal T2-weighted signal hyperintensity. Predisposing anatomical entities include cervical ribs, rib synostoses, hypertrophic callous following clavicular fracture, remnant first thoracic rib from prior incomplete resection, and variable perineural scarring. In comparison, DTOS patients frequently demonstrate signal hyperintensity and enlargement of the mid plexus (trunk and division level), with narrowing of the costoclavicular interval. Following comprehensive diagnostic workup that frequently includes electrodiagnostic testing, patients are directed to different management pathways. Nonsurgical management is considered for all cases of DTOS; all patients with NTOS or DTOS who fail conservative treatment warrant referral for a surgical opinion. If surgery is pursued, MRN can be helpful in preoperative planning.

A case of concomitant subclavian steal syndrome and thoracic outlet syndrome

A 59-year-old woman presented with dizziness and numbness of her left upper limb. Computed tomography (CT) angiography revealed an occlusion of the subclavian artery at its origin, leading to a diagnosis of subclavian steal syndrome. She was treated with percutaneous angioplasty and stenting; however, her symptoms did not improve. CT angiography of the arm in the elevated position revealed subclavian artery stenosis at the costoclavicular space, and the diagnosis was neurogenic thoracic outlet syndrome (TOS). First-rib resection was performed, and the symptoms disappeared immediately after surgery. TOS should be considered when symptoms persist despite subclavian steal syndrome treatment. Physical examination and CT imaging with the arm elevated aid in diagnosing TOS.

Intractable pain due to thoracic outlet syndrome successfully treated with percutaneous epidural adhesiolysis: A case report

Thoracic outlet syndrome (TOS) is characterized by intractable cervicobrachial pain caused by strangulation of the brachial plexus and subclavian artery by structures of the superior thoracic outlet. We describe percutaneous epidural adhesiolysis for refractory pain due to TOS. A man in his 40s had received nerve block therapy for right upper extremity pain of unknown origin for 5 years. Although imaging findings were negative for TOS, reproducible pain relieved by injection of a local anesthetic into the anterior scalene muscle suggested TOS due to compression by the muscle. Subsequently, since nerve block treatment had only temporary effect and the pain gradually worsened, right T1 epidural adhesiolysis was performed. Thereafter, the pain improved from a numerical rating scale score of 8-9/10 to 2-3/10, continuing for about 3 months. Epidural adhesiolysis was remarkably effective in treating intractable pain caused by TOS due to strangulation of the brachial plexus by the anterior scalene muscle.

Atypical articulation of the cervical rib and first rib

The cervical rib is an additional rib arising from the transverse process of the seventh cervical vertebra. This rib may terminate free in soft tissue or may be attached to the first rib. The cervical rib is a congenital anomaly that occurs in less than 1% of the general population and sometimes causes severe symptoms of thoracic outlet syndrome. Hereby, we report a 13-year-old boy with an atypical articulation between the left seventh cervical rib and the left first thoracic rib.

The management of thoracic outlet syndrome induced by bilateral cervical ribs in young, female athlete - a case report

INTRODUCTION

The presence of additional cervical ribs is a rare and relatively unknown pathology. The brachial plexus is most often compressed. Thoracic Outlet Syndrome (TOS) is the one of discussed of mixed compression syndromes, due to diagnostic difficulties and the lack of evidence to resolve the effectiveness of surgical treatment over conservative treatment.

CASE REPORT

Presentation of the case of a 22-year-old female athlete with cervical ribs with neurogenic TOS symptoms and presentation of the rehabilitation model and its results. Functional diagnosis included TOS specific clinical tests performed before, immediately after the treatment and one month later. The range of motion (ROM) in the cervical spine, body posture, the pulse on the left and right radial artery, blood pressure on both upper limbs, as well as pain intensity were examined. Management included 8 therapeutic sessions using trigger point therapy, deep tissue massage and cervical rotational manipulations. The maximum muscle relaxation and pain relief (decrease of 3-5 points in VAS) occurred after 5 therapeutic sessions. The rotation and lateral flexion in the cervical spine was significantly improved - the active ROM increased 2,5 in rotation bilaterally and 3,5/4 cm (left/right) in lateral flexion and passive ROM increased 3,5/3 cm (left/right) in rotation and 3.5/4.5 cm (left/right) in lateral flexion. The joint play of the cervical segments was normalized and the result of costo-clavicular test for the right side and the brachial stretch test for the left side become negative while the change of blood pressure in both upper limbs after the therapy as well as after one month was marginal ( ± 1-4 mmHg).

CONCLUSION

Conservative treatment based on the therapy of trigger points, deep tissue massage and rotational manipulations of the cervical spine appears to be an effective form of management of TOS induced by additional cervical ribs. However, further studies on are required to determine the most effective treatment options in this condition.

Novel Diagnosis and Treatment for Neurogenic Thoracic Outlet Syndrome

This article presents a unique diagnostic test for the neurogenic thoracic outlet syndrome (nTOS). nTOS is one of the most misdiagnosed and controversial medical problems; the diagnosis is clinical, and there are few specific diagnostic criteria for this condition. We would like to share this unique diagnostic modality, the Tafler test, with medical professionals. The Tafler test helps diagnose nTOS, differentiate it from cervical radiculopathy and carpal tunnel syndrome, and effectively tailor treatment for its symptoms. The following case series aims to describe several patients with nTOS who had failed previous treatment with surgery, physical therapy, and analgesics. The implementation of the Tafler test as a treatment modality in combination with osteopathic manipulative treatment (OMT) and physical therapeutic modalities led to significant improvements in treatment efficiency.

Diagnostic and Therapeutic Approach to Thoracic Outlet Syndrome

Thoracic outlet syndrome (TOS) is a group of symptoms caused by the compression of neurovascular structures of the superior thoracic outlet. The knowledge of its clinical presentation with specific symptoms, as well as proper imaging examinations, ranging from plain radiographs to ultrasound, computed tomography and magnetic resonance imaging, may help achieve a precise diagnosis. Once TOS is recognized, proper treatment may comprise a conservative or a surgical approach.

Arterial Thoracic Outlet Syndrome-A Case Study of a 23-Year-Old Female Patient Diagnosed Using a Thermal Imaging Camera

We present the case of a 23-year-old woman who reported weakness in the left upper limb, decreased warmth, numbness in the fingers, pain in the clavicular region, and a severe cold sensation in the limb. A thermal imaging camera examination was performed for diagnostic purposes, which guided further diagnostic and therapeutic management towards arterial thoracic outlet syndrome (aTOS). Following surgery and rehabilitation procedures, significant remission of symptoms was achieved and the patient's condition improved. This is the first report on the diagnosis of aTOS using thermal imaging, paving the way for further clinical research into this effective, rapid, and radiation-free method of diagnostic imaging. Conclusion: Thermal imaging is one of the most effective, readily available, and patient-safe methods for diagnosing vascular disease associated with flow disruption.

T1 erector spinae plane block for first rib resections in patients with thoracic outlet syndrome: a case series

An erector spinae plane block (ESPB), in which a local anesthetic is injected into the plane anterior to the erector spinae muscles, is a relatively new technique for delivering regional anesthesia and is typically performed in the mid-thoracic region. ESPBs demonstrate great potential to control regional neuropathic pain, and, accordingly, may be particularly effective at the T1 level for controlling pain in patients undergoing first rib resections for thoracic outlet syndrome (TOS). Four patients undergoing first rib resections for TOS were administered an ultrasound-guided ESPB at the T1 level. Two patients received the injection sitting upright without general anesthesia; the other patients received the block in the lateral decubitus position while under general anesthesia. Each patient's postoperative pain was adequately controlled, and no complications were observed. T1 ESPBs offer the potential to mitigate postoperative pain. Better pain management may decrease the need for opioids and shorten recovery times. As such, further investigation to establish the safety and efficacy of T1 ESPBs in this patient population can greatly improve patient outcomes.

Trans-Cervical Approach To The Thoracic Outlet Syndrome

Thoracic outlet syndrome is caused by compression of the neurovascular structures within the thoracic outlet leading to a collection of symptoms in the upper limb and shoulder. Identification of the causative factor is essential and thorough clinical examination using specific manoeuvres can aid in the diagnosis of this syndrome. Cervical rib is one of the causes for thoracic outlet syndrome and this manuscript will discuss the thoracic outlet syndrome, cervical rib, incidence, clinical presentation, diagnosis and management including surgical approaches with a focus on transcervical approach.

Consensus Recommendations for Neurogenic Thoracic Outlet Syndrome from the INTOS Workgroup

Background

There is significant variation in methods used for diagnosis and treatment of neurogenic thoracic outlet syndrome (NTOS). The lack of definitions and criteria for diagnosis as well as controversy in treatment options hampers standardized reporting of outcomes. In the orthopedic and plastic hand surgery literature, there are not standardized guidelines to direct evidence-based practice for hand surgeons relating to NTOS. Hence, expert consensus may provide guidance for clinical practice.

Methods

An international workgroup of 21 expert hand surgeons with cumulative experience of 5519 NTOS procedures was assembled. The Delphi method was used to arrive at consensus recommendations to guide diagnosis, treatment, surgery, and postoperative management of patients with NTOS.

Results

The workgroup achieved majority (greater than 75%) consensus with 17 statements. A modified version of the Society for Vascular Surgery clinical diagnostic criteria is recommended for diagnosis of NTOS. The elevated arm stress test and Tinel sign are recommended as provocative maneuvers. A cervical spine or chest radiograph should be routinely obtained preoperatively. Conservative management should be first line for NTOS, except in patients with significant muscle atrophy or weakness. An anterior supraclavicular approach is recommended for exposure of the supraclavicular brachial plexus, with the necessity for an additional infraclavicular approach or adjunctive surgeries indicated for specific patients.

Conclusions

Standardized consensus guidelines help guide management of NTOS by specialized hand surgeons, with an aim toward standardizing criteria for diagnosis and treatment of patients as well as measures and tools used for research and reporting of outcomes.

Endoscopically assisted transaxillary release of the scalene muscles for thoracic outlet syndromes: a comparison with or without first rib resection

OBJECTIVES

There are several surgical techniques for thoracic outlet syndrome (TOS). However, there have been no reports of endoscopically assisted transaxillary release of the anterior and middle scalene muscles (EATRS), leaving the first rib intact for TOS. We hypothesized that EATRS would achieve a good Quick Disability of the Arm, Shoulder and Hand score. This study aims to present our experience with a new technique for TOS using endoscopy.

METHODS

We chose two surgeries depending on the patient's TOS condition. If the costoclavicular space was under 12 mm, we selected endoscopically assisted transaxillary first rib resection (EAFRR). If the costoclavicular space was over 12 mm, we selected EATRS. Between January 2021 and December 2022, 31 consecutive surgeries for TOS were performed in our institution. Twenty-five patients underwent EAFRR, and six (19%) underwent EATRS. Since July 2022, EAFRR has been performed under differential lung ventilation.

RESULTS

Complete and almost complete relief was achieved in 24 patients (77%), and partial relief was conducted in seven patients (23%) at a mean of 19.7 months after surgery. The symptoms improved in all cases. Intraoperative pneumothorax did not occur, and no other complications were observed. Both EAFRR and EATRS were effective and safe surgeries for TOS. Operative time was significantly shorter in EATRS than in EAFRR.

CONCLUSIONS

We first report EATRS surgery for TOS. EATRS is indicated for patients whose costoclavicular space is preserved before surgery. Good surgical results were obtained after surgery for this indication.

Sports-related peripheral nerve injuries of the upper limb

Peripheral nerve injuries in athletes affect the upper limb more commonly than the lower limb. Common mechanisms include compression, traction, laceration, and ischemia. Specific sports can have unique mechanisms of injury and are more likely to be associated with certain neuropathies. Familiarity with these sport-specific variables and recognition of the common presentations of upper limb neuropathic syndromes are important in assessing an athlete with a suspected peripheral nerve injury. Evaluation may require imaging modalities and/or electrodiagnostic testing to confirm a nerve injury. In some cases, diagnostic injections may be needed to differentiate neuropathic versus musculoskeletal etiology. Early and accurate diagnosis is essential for treatment/management and increases the likelihood of a safe return-to-sport and avoidance of long-term functional consequences. Most nerve injuries can be treated conservatively, however, severe or persistent cases may require surgical intervention. This monograph reviews key diagnostic, management, and preventative strategies for sports-related peripheral nerve injuries involving the upper limb.

A rare case of overlapping thoracic outlet syndrome attributed to an anatomical variation in the anterior scalene muscle: Diagnostic challenges and treatment approaches

Mixed thoracic outlet syndrome, which compresses arteries and nerves, is a rare disorder. Mixed thoracic outlet syndrome due to anatomical abnormalities of the anterior scalene muscle is even more sporadic. We report a case of mixed thoracic outlet syndrome in a patient with no history of trauma or vigorous exercise. We reviewed the medical literature, emphasizing the clinical role and the role of diagnostic imaging methods in a sequential approach to this syndrome.

Differentiating Shoulder Pathology from Cervical Spine Pathology: An Algorithmic Approach

Accurate and timely diagnosis of musculoskeletal conditions is an essential component of high-quality orthopaedic care. The proximity of the shoulder to the cervical spine leads to a multitude of pathologic conditions whose clinical presentations overlap, posing a diagnostic challenge to orthopaedic providers. Missed or delayed diagnosis of the etiology for patient-described 'shoulder pain' causes frustration among patients, incurs increased healthcare costs, and delays treatment. Moreover, patients with concurrent conditions of the cervical spine and shoulder require deliberate consideration for how each condition contributes to patients' symptoms. The purpose of this review was to describe a systematic approach for evaluating and differentiating pathologies of the shoulder and cervical spine.

A review of arterial thoracic outlet syndrome

Arterial thoracic outlet syndrome (TOS) is a condition in which anatomic abnormalities in the thoracic outlet cause compression of the subclavian or, less commonly, axillary artery. Patients are usually younger and typically have an anatomic abnormality causing the compression. The condition usually goes undiagnosed until patients present with signs of acute or chronic hand or arm ischemia. Workup of this condition includes a thorough history and physical examination; chest x-ray to identify potential anatomic abnormalities; and arterial imaging, such as computed tomographic angiography or duplex to identify arterial abnormalities. Patients will usually require operative intervention, given their symptomatic presentation. Intervention should always include decompression of the thoracic outlet with at least a first-rib resection and any other structures causing external compression. If the artery is identified to have intimal damage, mural thrombus, or is aneurysmal, then arterial reconstruction is warranted. Stenting should be avoided due to external compression. In patients with symptoms of embolization, a combination of embolectomy, lytic catheter placement, and/or therapeutic anticoagulation should be done. Typically, patients have excellent outcomes, with resolution of symptoms and high patency of the bypass graft, although patients with distal embolization may require finger amputation.

Case report on the diagnosis of vascular thoracic outlet syndrome followed by mechanical thrombectomy

INTRODUCTION AND IMPORTANCE

The thoracic outlet syndrome is characterized by compression of the brachial plexus or subclavian vessels due to anatomical alterations of the thoracic cavity. Vascular presentation is rare and includes thromboembolism and edema in the upper limb, and the diagnosis is often elusive due to its rarity. In this case, we describe a vascular thoracic outlet syndrome presentation whose diagnosis through angiography was achieved after a mechanical thrombectomy.

CASE PRESENTATION

We report a 43-year-old female patient with pain in the right upper limb, accompanied by edema and mild violet discoloration, without risk factors for hypercoagulability, with D-dimer levels within normal values. Mechanical thrombectomy with AngioJET was performed via an endovascular approach, with the extraction of multiple clots, confirming the presence of thoracic outlet syndrome as the underlying cause of the current condition.

CLINICAL DISCUSSION AND CONCLUSIONS

Venous thoracic outlet syndrome is a challenging entity to diagnose; however, it should be considered in cases of deep vein thrombosis of the subclavian vein and confirmed by angiography after a thrombectomy.

Diagnosis of thoracic outlet syndrome with the lower trunk compression of brachial plexus by high-frequency ultrasonography

BACKGROUND

Thoracic outlet syndrome (TOS) with the lower trunk compression of brachial plexus (BP) is difficult to diagnosis. This study aimed to summarize the features of thoracic outlet syndrome (TOS) with the lower trunk compression of brachial plexus observed on high-frequency ultrasonography (HFUS).

METHODS

The ultrasound data of 27 patients who had TOS with the lower trunk compression of brachial plexus were collected and eventually confirmed by surgery. The imaging data were compared, and the pathogenesis of TOS was analyzed on the basis of surgical data.

RESULTS

TOS occurred predominantly in females (70.4%). Most cases had unilateral involvement (92.6%), mainly on the right side (66.7%). The HFUS features of TOS can be summarized as follows: (1) Lower trunk compression. HFUS revealed focal thinning that reflected compression at the level of the lower trunk; furthermore, the distal part of the nerve was thickened for edema (Affected side: 0.49 ± 0.12 cm vs. Healthy side: 0.38 ± 0.06, P = 0.009), and the cross-sectional area of brachial plexus cords was markedly greater on the injured side than on the healthy side (0.95 ± 0.08 cm² vs. 0.65 ± 0.11 cm², P = 0.004). (2) Hyperechoic fibromuscular bands behind the compressed nerve (mostly the scalenus minimus muscle). (3) Abnormal bony structures: cervical ribs or elongated transverse processes of the 7th cervical vertebra (C7). Surgical results showed that the etiological factors contributing to TOS were (1) muscle hypertrophy and/or fibrosis (100%) and (2) cervical ribs/elongated C7 transverse processes (20.7%).

CONCLUSION

TOS with the lower trunk compression of brachial plexus can be diagnosed accurately and reliably by high-frequency ultrasound.

Body Composition and Demographic Features Do Not Affect the Diagnostic Accuracy of Shear Wave Elastography

Shear-wave elastography (SWE) is an imaging method that can be used to estimate shear wave speed and the Young's modulus based on the measured shear wave speed under certain conditions. Up to date, no research has analyzed whether body composition factors contribute to ultrasound attenuation, refraction, reflection, and, consequently, SWE measurement errors. Therefore, this study aimed to analyze the association between demographic and body composition features with SWE errors for assessing the anterior scalene stiffness (which is a key structure in patients with neck pain and nerve compressive syndromes). Demographic (sex, age, height, weight, and body mass index), body composition (water volume, fat mass, and lean mass), and anterior scalene muscle stiffness (Young's modulus and shear wave speed) data were collected from a sample of asymptomatic subjects. After calculating the absolute SWE differences between trials and the reliability estimates, a correlation matrix was generated to quantify the association among all the variables. A total of 34 asymptomatic subjects (24 males) were included in the analyses. Test-retest reliability was excellent for assessing the Young's modulus and shear wave velocity (ICC = 0.912 and 0.923, respectively). No significant associations were found between age, height, weight, body mass index, body fat, lean mass, or water volume with SWE errors (p > 0.05). However, the Young's modulus error was associated with the stiffness properties (p < 0.01), whereas shear wave speed was associated with none of them (all, p > 0.05). A detailed procedure can reliably assess the AS muscle stiffness. None of the sociodemographic or body composition features assessed were correlated with SWE errors. However, baseline stiffness seems to be associated with Young's modulus error.