Definition of science and technology Chinese name: syndrome of chest outlet English name: syndrome of chest outlet Definition: syndrome caused by compression of the brachial plexus nerve and subclavian artery and vein at the thoracic outlet and the rostral attachment of the pectoralis minor muscle. Applied Discipline: First level of Chinese medicine; second level of orthopedic and traumatic diseases; second level of tendon injuries Encyclopedia Business card The syndrome of chest outlet is a series of symptoms caused by compression of the subclavian artery and vein and the brachial plexus nerve at the upper thoracic opening. For example, coldness in the arm, easy fatigue or dull pain in the shoulder arm or hand, and difficulty in performing activities of the upper extremity over the head. Contents Overview Anatomy and etiology Diagnosis Differential diagnosis Treatment Good review hospital Good review doctor Expand Overview Anatomy and etiology Diagnosis Differential diagnosis Treatment Good review hospital Good review doctor Expand Overview Affiliation : Chest Thoracic outlet syndrome Department : Cardiothoracic Surgery Hand Surgery Surgery Symptoms and signs : Cyanosis Fatigue Cough abnormal breathing Thoracic outlet syndrome is a series of symptoms caused by compression of subclavian artery, vein and brachial plexus nerve in the upper thoracic orifice. A series of symptoms. The symptoms include cold arms, easy fatigue or dull pain in the shoulder arm or hand, and difficulty in performing activities of the upper extremities beyond the head. Anatomy and etiology The anterior oblique muscle starts from the anterior node of the transverse processes of the 3rd to 6th cervical vertebrae, and the muscle fibers travel forward and downward, ending at the anterior oblique muscle node in front of the subclavian artery groove at the anterior superior edge of the 1st rib Thoracic outlet syndrome, and the middle oblique muscle starts from the posterior node of the transverse processes of all cervical vertebrae, with a few starting from the posterior node of the transverse processes of the 2nd to 7th, 3rd to 7th, or 3rd to 7th cervical vertebrae, and ending outward in the posterior subclavian artery groove above the 1st rib or posteroposteriorly. The anterior and middle oblique muscles form a triangular gap with the 1st rib, called the oblique gap. The vascular nerves of the upper extremity include the brachial plexus nerve and the subclavian artery and vein. After the subclavian artery emanates from the aortic arch, it crosses the 1st rib in an arch shape, crosses the oblique angle muscle gap and enters the intercostal lock space. The subclavian vein does not pass through the oblique angle muscle gap, but crosses anteriorly from the anterior oblique angle muscle and injects into the jugular vein. The brachial plexus nerve consists of the anterior branches of C5 to T1 nerve roots, each of which exits the intervertebral foramen and travels outward and downward, crossing the oblique horn muscle space just above the subclavian artery. C5 and C6 nerve roots form the superior trunk of the brachial plexus nerve, C7 nerve roots form the middle trunk alone, and C8 and Tl nerve roots form the inferior trunk of the brachial plexus nerve, of which the inferior trunk crosses directly over the first rib, and each trunk is divided into two strands that travel together anteriorly and posteriorly through the intercostal lock space The lower trunk directly crosses the 1st rib, and each trunk is divided into anterior and posterior strands that travel together in the intercostal clavicular space, passing outward and downward through this space and then into the posterior interstitial space behind the pectoralis minor muscle and then into the axilla. Around the nerve and vascular bundle, there is a neurovascular sheath formed by fibrous connective tissue. Of the above-mentioned strokes of the brachial plexus nerve, it is most vulnerable to compression at the following sites: 1) the oblique angle muscle gap; 2) the intercostal lock gap; and 3) the posterior interrogative gap of the pectoralis minor muscle. Any congenital or acquired abnormality in the above anatomical sites can directly or indirectly compress the subclavian vessels and the brachial plexus nerve, producing clinical symptoms. Congenital anatomical anomalies include bony anomalies and soft tissue anomalies. Common bony anomalies include cervical ribs, hypertelorism of the 7th cervical vertebra, and superior thoracic outlet syndrome of the 1st rib narrowing the costoclavicular space. Soft tissue abnormalities can be due to hypertrophy of the anterior and middle oblique muscles; congenital fasciculations of the oblique muscles, mostly forming a fasciculation between the anterior oblique muscles and the lth rib, compressing the vascular nerves; contracture of the oblique muscles, small gap of the oblique muscles; abnormal stopping points of the pectoralis minor muscles and congenital abnormal fiber fasciculation compression in other areas. Acquired factors include muscle tissue hyperplasia and atrophy at the above anatomical sites resulting in muscle strength imbalance, anatomical position changes, and compression of vascular nerve bundles. People with long necks and scapular band hypoplasia are prone to thoracic outlet syndrome. In addition, trauma also plays a role in the occurrence of thoracic outlet syndrome. Fractures of the clavicle and ribs may not only directly damage the subclavian vessels and brachial plexus nerve, but may also be caused by abnormal healing of the fracture, abnormal scab growth, local scar tissue proliferation, and hemorrhagic edema after muscle tissue injury. In addition, pseudoaneurysms from vascular injury or tumors at the thoracic outlet can also directly compress the brachial plexus nerve. Among the above causes, oblique myelopathy is the most common, followed by cervical ribs, while stenosis of the intercostal clavicular space and pectoralis minor muscle space is rare. Diagnosis Overview The disease can occur in people aged 15 to 60 years, with the highest incidence in women aged 20 to 40 years, probably because the incidence of cervical ribs is one times higher in women than in men, and the thoracic outlet syndrome is associated with weaker muscle strength in women and more scapular girdle prolapse than in men, which can cause tension of the brachial plexus nerve and narrowing of the intercostal lock gap, leading to spasm of the oblique muscles and compression of the vascular nerve bundle. Thoracic outlet syndrome is mainly a clinical symptom of brachial plexus nerve and subclavian artery compression. Clinical phenotype 1. Brachial plexus nerve compression: The lower trunk of the brachial plexus nerve across the 1st rib is most easily compressed, and the upper trunk is less compressed, mainly showing symptoms of compression of the lower trunk of the brachial plexus nerve. Patients mainly present with pain and weakness in the affected shoulder and upper extremity. The pain is intermittent in the early stage of the disease and may radiate to the ulnar side of the forearm and hand, and the pain increases when the shoulder is abducted and internally rotated. In severe cases, there may be abnormal sensation in the forearm and ulnar side of the hand, and even muscle paralysis. The muscle paralysis and atrophy are more severe in the small interosseous muscle and the bone question muscle, showing claw-shaped hand deformity, and sometimes there is also muscle weakness in the large interosseous muscle and forearm muscle. There is pressure pain in the supraclavicular region and it radiates to the forearm. In most cases, the anterior oblique muscle tension test is positive. The test is performed by sitting the patient with the head turned to the healthy side and the neck hyperextended, while pulling the healthy arm downward, and the numbness and pain of the affected limb increases and radiates to the distal end as positive. 2, vascular compression: generally patients do not appear serious blood flow disorders, when the lesion stimulates the blood vessels, can appear upper limb set of abnormal sensation, the affected limb when lifting the feeling of cold, pale color, radial artery pulsation is weakened, when the subclavian vein is severely compressed, the affected limb distal edema, cyanosis. Adson’s sign and Roos’ sign are often positive. 1.Adson’s sign: the patient sits with his hands on his knees, turns his head to the affected side, lifts his jaw to straighten his neck, asks the patient to inhale deeply and then holds his breath, if the radial artery pulsation is weakened or disappears, the test is positive. 2.Wright’s sign: the patient sits with one hand touching the radial artery. The examiner touches the radial artery of the patient with one hand, while the upper arm is passively and excessively abducted, if the radial artery pulsation is weakened or disappears, and a murmur appears in the axilla, it is positive; 3.R∞s sign: the patient’s upper limbs are bilaterally abducted by 90 and externally rotated, and the patient is asked to make continuous and rapid finger extension and flexion movements with both hands, if there is increased pain, weakness, and the affected limbs fall automatically, it is positive. Electrophysiological examination If used properly, electrophysiological examination can determine the level of nerve injury and help to identify myogenic or neurogenic lesions. The abnormalities of electromyography in this disease are often limited to the internal muscles of the hand and are characterized by the presence of fibrillatory potentials, decreased motor unit potentials MuP, and other chronic neurogenic lesions. The changes in the nerve conduction study NCS are characteristic of thoracic outlet syndrome and are characterized by decreased amplitude or failure to elicit the sensory nerve action potential SNAP of the medial forearm, slightly decreased amplitude of the sensory nerve action potential of the ulnar nerve, and decreased amplitude of the median nerve action potential of the median nerve. F-wave prolongation. The typical change in the SEPs of somatosensory evoked potentials is abnormal SEPs of the ulnar nerve and normal SEps of the median nerve, often showing attenuation of the amplitude of the N9 response of the ulnar nerve, with or without attenuation of the amplitude of the N13 response. X-ray examination is an important test to assist in the diagnosis of the disease. Orthopantomographs of the cervical spine can reveal the presence of cervical ribs and overgrowth of the transverse processes of the 7th cervical vertebrae, while thoracic films and tangential films of the clavicle can reveal deformities of the clavicle and ribs. Sometimes, MRI can help to find out whether there is a tumor in the supraclavicular region and whether there is a fibrous band compressing the vascular nerve, but some people disagree that MRI cannot find the fibrous band compressing the brachial plexus nerve. Based on the above clinical manifestations, a comprehensive analysis of symptoms, signs, x-ray and electrophysiological examination results, it is not difficult to make a diagnosis of thoracic outlet syndrome. Differential diagnosis Cervical spondylosis can also present with pain, weakness and abnormal sensation in the upper limbs, but patients with cervical spondylosis often have pressure pain in the neck, and the head press test and brachial plexus nerve pull test are often positive Thoracic outlet syndrome Degenerative changes such as cervical spur hyperplasia, narrowing of the vertebral space and changes in the hook vertebral joints can be seen on CT and MRI. Elbow canal syndrome is a clinical syndrome caused by the compression of the ulnar nerve in the elbow canal, manifesting as hand weakness, abnormal sensation on the ulnar side of the affected limb, atrophy of the interosseous and interosseous muscles, and claw-shaped hand, similar to the clinical manifestations of the disease mainly involving the ulnar nerve, but the former does not have shoulder symptoms, does not affect the median nerve, and the signs are limited to below the elbow, with special tests such as AdSOn’s sign, wright’s sign, f0Os sign, etc. AdSOn’s sign, Wright’s sign, f0Os sign and other special tests are negative. Carpal tunnel syndrome is caused by compression of the median nerve in the carpal tunnel, mainly manifesting as sensory disorders in the radial 2/3 and radial 3.5 fingers of the hand and thumb to palm dysfunction, which are not difficult to identify by clinical symptoms and examination. Treatment Non-surgical treatment If the patient has mild symptoms and no nerve injury, non-surgical treatment can be used, including suspension of the upper limb, appropriate rest Thoracic outlet syndrome rest, local physiotherapy, local closure of the anterior oblique muscle, oral painkillers and non-steroidal anti-inflammatory drugs, weight reduction, and strengthening the functional exercise of the shoulder. If treatment is not effective, surgical treatment should be used. Surgical treatment If non-surgical treatment is ineffective, or if the patient has severe symptoms, hyperalgesia, muscle atrophy paralysis and other manifestations of nerve damage, surgery should be performed as soon as possible to release the compression of the brachial plexus nerve and subclavian arteries and veins. There are many surgical approaches and surgical maneuvers for this disease. The surgical approaches commonly used in clinical practice are supraclavicular oblique myotomy and transaxillary 1st rib resection. Through this surgery, the following objectives can be achieved: 1) removal of various muscle tissues in the neck that compress the brachial plexus nerve and subclavian vessels, such as anterior oblique muscle, middle oblique muscle and scapular hyoid muscle; 2) removal of bony tissues that produce compression, such as the 1st rib and cervical ribs; 3) removal of various muscle fiber tracts and ligaments that produce vascular nerve compression, and also release of the suprascapular brachial plexus nerve. It can be divided into two kinds of treatment: conservative treatment and surgical treatment. 1. Conservative treatment is suitable for people with mild symptoms and initial onset, and the methods are: 1. 1% procaine 5ml plus hydrocortisone 1ml is injected into the local muscle in the pressure pain area of the left or right supraclavicular fossa, once a week, 3 to 5 times as a course of treatment. The effect is obvious if the local muscle has a history of strain. 2.Oral dexamethasone, prednisone and anti-inflammatory pain drugs. 3.Physiotherapy: the supraclavicular fossa is treated with transheat therapy or iodine ion penetration. 4.Body therapy for shoulder girdle muscle exercise and neck traction, etc. Surgical treatment is suitable for those whose symptoms do not improve or even worsen after 1 to 3 months of non-surgical treatment, and whose ulnar nerve conduction velocity through the thoracic outlet is less than 60m/s; those whose angiogram shows obvious obstruction of the subclavian artery and vein; and those with severe local pain or significant symptoms of venous compression. The principle of surgery is to release the bony scissor-like compression of the vascular nerve bundle. The full length of the first rib must be amputated and the relevant compression factors must be removed, so that the brachial plexus and subclavian artery can be moved down without producing deformity complications. There are two surgical routes: a. Axillary route General anesthesia or high epidural anesthesia, reclined position, 45° elevation of the affected limb, and a 6-7 cm long transverse incision at the level of the 3rd rib at the inferior edge of the axillary hair after lifting the upper limb. The incision was dissected between the pectoralis major and latissimus dorsi muscles to the thorax and separated upward under the fascia to the top of the axilla. The neurovascular bundle is seen at the upper edge of the 1st rib. The upper limb is lifted so that the neurovascular bundle leaves the 1st rib, the anterior oblique muscle is cut, and the 1st rib and periosteum are excised, anteriorly to the costal cartilage and posteriorly to the transverse process, after which the bone stump is examined for compression of the brachial plexus. This procedure is less invasive and less bleeding, but poorly exposed and prone to incomplete resection of the 1st rib. The patient is placed in an oblique lateral position with the upper limb raised, and the incision is made above the third rib to the lower edge of the axillary hair. II. The incision starts from the high parascapular region and goes downward along the inner scapula towards the axilla. The latissimus dorsi, rhomboid and anterior serratus muscles are cut. The scapula is propped upward and outward, and the middle oblique muscle fibers are cut to expose the 1st rib. The posterior segment of the 2nd rib is removed to increase the exposure of the 1st rib and decompress the 2nd intercostal nerve. The cervical scoliosis or rounded vertebral thorax also serves to widen the parietal space. The 1st oblique muscle and the full length of the 1st rib are cut, while bony abnormalities such as cervical ribs, excessive length of the transverse processes of the vertebral body and abnormal fibrous bands should be removed, and the incision is large and careful hemostasis is required at the end of the operation to prevent post-hematoma mechanized adhesions. This incision can satisfactorily amputate the 1st rib and relieve the relevant compression factors, and is suitable for re-operation patients. The disadvantage is that it is more invasive and bleeds more. Surgical complications include injury to the pleura causing pneumothorax, numbness and weakness of the arm due to intraoperative stretching of the brachial plexus, or infection of the postoperative hematoma. Postoperatively, symptoms disappear in about 90% of cases.