暂无摘要。

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

A positive response to scalene muscle block (SMB) is an important indication for the diagnosis of thoracic outlet syndrome. Lidocaine injection is commonly used in clinical practice in SMB, although there have been some cases of misdiagnosis. Botulinum toxin A (BTX-A) is one of the therapeutic agents in SMB, but whether it is also indicated for SMB diagnosis is controversial. To evaluate the muscle block efficiency of these two drugs, the contraction strength was repeatedly recorded on tibialis anterior muscle in rats. It was found that at a safe dosage, 2% lidocaine performed best at 40 μL, but it still exhibits an unsatisfactory partial blocking efficiency. Moreover, neither lidocaine injection in combination with epinephrine or dexamethasone nor multiple locations injection could improve the blocking efficiency. On the other hand, injections of 3, 6, and 12 U/kg BTX-A all showed almost complete muscle block. Gait analysis showed that antagonistic gastrocnemius muscle, responsible for heel rising, was paralyzed for nonspecific blockage in the 12 U/kg BTX-A group, but not in the 3 U/kg or 6 U/kg BTX-A group. Cleaved synaptosomal associated protein 25 (c-SNAP 25) was stained to test the transportation of BTX-A, and was additionally observed in the peripheral muscles in 6 and 12 U/kg groups. c-SNAP 25, however, was barely detectable in the spinal cord after BTX-A administration. Therefore, our results suggest that low dosage of BTX-A may be a promising option for the diagnostic SMB of thoracic outlet syndrome. SIGNIFICANCE STATEMENT: Muscle block is important for the diagnosis and treatment of thoracic outlet syndrome and commonly performed with lidocaine. However, misdiagnosis was observed sometimes. Here, we found that intramuscular injection of optimal dosage lidocaine only partially blocked the muscle contraction in rats, whereas low-dosage botulinum toxin, barely used in diagnostic block, showed almost complete block without affecting the central nervous system. This study suggests that botulinum toxin might be more suitable for muscle block than lidocaine in clinical practice.

Patients presenting with periodic swelling of the upper extremity without thrombosis are diagnosed with McCleery syndrome. There have been sporadic cases reported over the past decades. Due to the rarity of this disease, no standard consensus on diagnosis and treatment of McCleery syndrome was established. Subclavius tendon and anterior scalene muscle compression were proposed as the primary cause of McCleery syndrome. Partial resecting muscle, tendon or ligament was recommended as therapies. We report one rare case of membranous occlusion of the subclavian vein (SCV) that leads to periodic swelling of upper extremity and diagnosis of McCleery syndrome was made. This 21-year-old man complained of swelling and pain in the right upper extremity after strenuous exercise lasting for 3 months. Physical examination, spinal X-ray and magnetic resonance imaging showed no signs related to classic venous thoracic outlet syndrome (VTOS). Duplex ultrasonography demonstrated membranous occlusion without thrombosis at the proximal end of the right SCV. The lesion was confirmed by venography. Treated by balloon dilation alone, the patient recovered uneventfully during 18 months of follow-up. Repeated duplex ultrasonography revealed patency of the SCV. To our best knowledge, our case provides the first reported membranous occlusion of the SCV. Excluding the presence of thrombosis in SCV, he was diagnosed with McCleery syndrome and was cured by balloon dilation alone. We can learn from this rare case that membranous occlusion of veins can be a rare cause of McCleery syndrome and is worthy of careful consideration and differentiation of VOTS.

OBJECTIVE: Venous thoracic outlet syndrome (VTOS) is a compressive disorder of subclavian vein (SCV); we aimed to investigate the role of costoclavicular ligament (CCL) in the pathogenesis of VTOS.
METHODS: A cadaver study was carried out to investigate the presence and morphology of CCL in thoracic outlet regions, as well as its relationship with the SCV. Six formalin-fixed adult cadavers were included, generating 12 dissections of costoclavicular regions (two sides per cadaver). Once CCL was identified, observation and measurement were made of its morphology and dimensions, and its relationship with SCV was studied. To take a step further, a clinical VTOS case was reported to prove the anatomical findings.
RESULTS: Two out of twelve costoclavicular regions (2/12, 16.7%) were found to possess CCLs. Both ligaments were located in the left side of two male cadavers and were closely attached to the lateral aspect of sternoclavicular joint capsules. The lateral fibers of the ligament proceed in a superolateral-to-inferomedial manner, while the medial fibers proceed more vertically. Both ligaments were tightly adherent to the SCV, causing significant compression on the vein. In the clinical case, multiple bunches of CCLs were found to compress the SCV tightly intraoperatively. After removing the ligaments, the patient\'s symptom kept relief during a follow-up period of 2 years.
CONCLUSIONS: Our study demonstrated that CCL could be a novel cause of VTOS by severe compression of SCV. Patients diagnosed with this etiology could get less invasive surgical treatment by simply removing the ligament.

BACKGROUND: Venous thoracic outlet syndrome (VTOS) secondary to subclavian arterial stent implantation is extremely rare. Here, we firstly report this disease and the endovascular intervention using covered-stents.
METHODS: An 80-year-old man who had received an acceptable stent implantation for the treatment of a right subclavian arteriovenous malformation (AVM), presented with a gradually increasing swelling and pain in his right upper extremity.
METHODS: The patient was diagnosed with right VTOS and recurrent subclavian AVM following ultrasonography and computed tomographic angiography.
METHODS: We positioned a covered-stent in the subclavian artery to block the feeding arteries and successfully embolized the remaining branches with coils. Next, we performed successful dilation 3 times, followed by the positioning of another covered-stent in the right subclavian vein.
RESULTS: The patient was free of all symptoms and the imaging procedures confirmed an acceptable thrombosis of the AVM with patent stents in the right subclavian artery and vein during the 6-month follow-up.
CONCLUSIONS: Venous stent implantation is an alternative to treat VTOS caused by subclavian arterial stents and it is essential to pay more attention to the incidence of VTOS following arterial stent implantation in the subclavian artery.

BACKGROUND The aim of this study was to introduce a novel method combining contrast-enhanced magnetic resonance angiography (CE-MRA), short inversion time inversion recovery sampling perfection with application-optimized contrasts using different flip angle evolutions (T2-STIR-SPACE) and volumetric interpolated breath-hold examination (VIBE) sequences in the assessment of thoracic outlet syndrome (TOS). MATERIAL AND METHODS CE-MRA, T2-STIR-SPACE, and VIBE techniques were employed to evaluate neurovascular bundles in 27 patients clinically suspected of TOS. Images were evaluated to determine the cause of neurovascular bundle compression. Surgical exploration was performed in patients with abnormal magnetic resonance imaging (MRI) results. RESULTS Twenty patients were found to be abnormal: 6 cases showed only neurogenic TOS and the correlates included infraclavicular hemangiomas (n=1) and transverse cervical artery (n=5). Arterial-neurogenic TOS was found in 4 cases, including subclavian lymph node metastasis from breast cancer (n=3) and schwannoma (n=1). Arterial-venous-neurogenic TOS was found in 1 subject, and the correlates included a fibrous band from the cervical rib and elongated C7 transverse process. In this case, the subclavian artery/vein was compressed dynamically. Venous-neurogenic TOS was noted in one subject. Nine patients were considered as post-traumatic TOS, including brachial plexus edema (n=3), the brachial plexus rupture (n=2), peri-brachial plexus effusion (n=3), and stenosis of the SCA (n=1). In the remaining 7 patients, MRI did not detect abnormalities. CONCLUSIONS TOS can be evaluated by CE-MRA, T2-STIR-SPACE, and VIBE during a single examination, with a reduced contrast material dose. This imaging modality performs well in showing the anatomical structure of the neurovascular bundle and the cause of the compression.

Thoracic outlet syndrome(TOS) are constellation of symptoms caused by compression of the neurovascular bundle including the brachial plexus, the subclavian artery and the subclavian vein at the thoracic outlet region. It includes neurogenic TOS, venus TOS, arterial TOS, and neurogenic TOS is the most common type. TOS has varied manifestations and lack of confirmatory testing, therefore, the diagnosis should be conbination with thorough history, physical examination and associated supplementary examinations. Conservative and surgical treatment can be choosed for TOS and the outcomes are generally good. Conservative management is the initial treatment strategy for neurogenic TOS. In cases of symptomatic vascular TOS and neurovascular TOS, which has been failed by conservative treatment, surgery should be considered more promptly.

BACKGROUND: Thoracic outlet syndrome (TOS) is a rare disease that presents with neurogenic and vascular symptoms similar to those of cervical spondylosis. However, making the diagnosis of TOS can be challenging due to a lack of standardized objective confirmatory tests.
UNASSIGNED: A 66-year-old man presented with neck, supraclavicular, and right shoulder pain as well as numbness and weakness in the right arm after surgery to correct cervical spondylotic myelopathy (CSM).
METHODS: Magnetic resonance imaging confirmed the diagnosis of CSM. He was diagnosed with TOS based on the manifestations and examination findings.
METHODS: After surgery for CSM, nonoperative management was provided.
RESULTS: The patient reported pain relief and improving sensation in the shoulder and supraclavicular region.
CONCLUSIONS: Based on this case and the reviewed literature, to optimize the diagnosis and treatment of CSM, clinicians should consider preoperative differential diagnosis to preliminarily exclude it.

BACKGROUND: Cervical ribs are rare conditions, occurring in 0.05% to 3.0% of the population. This manuscript reports a case of arterial thoracic outlet syndrome (ATOS) associated with this congenital anomaly.
UNASSIGNED: We report a 32-year-old female worker presenting pain in her left upper-extremity for 7 months. Her left hand became paler and cold when the temperature decreased, and the symptoms could not be eased through rest, physiotherapy and drugs medication.
UNASSIGNED: Compression of left subclavian artery with axillary and brachial arteries thrombosis was confirmed by duplex ultrasound and computed tomography angiography. ATOS caused by cervical ribs was confirmed by medical history, physical examination, and imaging.
METHODS: The patients underwent acute thrombolysis and balloon angioplasty.
RESULTS: Symptoms of pain and weakness disappeared after surgery. The patient had not experienced any apparent symptom recurrence at 1-year follow-up.
CONCLUSIONS: Successful treatment of ATOS depends upon urgent assessment, accurate identification of causative factors and compression site and early diagnosis before the event of arterial thrombosis. The surgery combined with anticoagulation treatment can improve the treatment outcome of ATOS.