Introduction
Thoracic outlet syndrome is a group of complex conditions to diagnose and treat. Treatment of thoracic outlet syndrome has a high recurrence rate and morbidity. The new approach of minimally invasive treatment can reduce morbidity and improve healing. The treatment of minimally invasive spine surgery for complete resection of the first cervical rib is a newer treatment option. The surgery is performed through a costo-transversectomy approach (lateral spine and costovertebral joints can be accessed). Studies are ongoing on other robot or video-assisted procedures to improve treatment outcomes.
What Is Thoracic Outlet Syndrome?
Congenital anomaly in the cervical rib causes the development of a partial rib from the seventh cervical vertebrae. The partial rib compresses structures in the shoulder or upper thoracic regions. The compression pressure may be exerted by the rib or a fibrous band attached to the ribs. It results in the formation of thoracic outlet syndrome. Cervical rib anomalies are often bilateral and more predominant in women. The condition is frequently diagnosed in individuals between the age group of 25 to 40 years. In a few patients, thoracic outlet syndrome develops due to trauma or injury to the region.
What Are the Causes of Thoracic Outlet Syndrome Development?
Many congenital or acquired conditions can cause compression of neurovascular structures. The likely causes include bone anomalies of the cervical rib, transverse mega-apophyses (elongation of the transverse process of vertebrae), first rib abnormalities, non-union of the clavicle (collar bone), soft tissue anomalies that include fibrous band or cervical muscle hypertrophy (increase in growth of muscle cells), drooping or sagging of shoulder or poor posture due to large breasts.
What Are the Types of Thoracic Outlet Syndrome?
There are four types of the disorder.
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Neurogenic Thoracic Outlet Syndrome: This disorder forms up to 85 to 90 % of all thoracic outlet syndrome. It is caused by brachial plexus compression (a network of nerves that supply skin and muscles in the shoulder). Healthcare providers may suggest surgery if symptoms do not resolve.
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Venous Thoracic Outlet Syndrome: In this condition, the subclavian artery is compressed (which supplies oxygenated blood to the upper body).
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Arterial Thoracic Outlet Syndrome: In this form, there is compression of the subclavian vein (a vein responsible for transporting oxygen-poor blood from the upper body to the heart).
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Disputed Thoracic Outlet Syndrome: It is a non-specific disorder with unclear origin.
What Are the Symptoms Associated With Thoracic Outlet Syndrome?
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Pain is present in the chest wall, armpit, shoulders, and neck. The pain is of a burning type and intensifies with movement.
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Numbness in fingers.
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Weakness in the affected side of the arm and hand.
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Atrophy (reduction of size) of muscles.
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Paresthesia (tingling or prickling sensation).
How to Diagnose Thoracic Outlet Syndrome?
Diagnosis of thoracic outlet syndrome is difficult due to the lack of a specific test for disease identification. Physical evaluation of the shoulder, upper extremities, and spine is necessary.
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Pain X-ray: Cervical spine is imaged to identify bone anomalies.
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Magnetic Resonance Imaging: The neck and soft tissue are examined to rule out other conditions like ruptured discs, spinal stenosis (spinal narrowing), or neurologic conditions.
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Electromyography: This test is helpful in the differential diagnosis of other disorders.
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CT- Angiography: It is essential for planning surgical approaches in diagnosed patients. The imaging can detect anatomic anomalies such as an abnormal first rib, abnormal C7 (7th cervical vertebrae), and the presence or absence of a cervical rib.
How to Treat Thoracic Outlet Syndrome?
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Conservative Approach: It is the first line of treatment for the neurogenic form of thoracic outlet syndrome. The conservative approach includes patient education, rehabilitation, and administration of medication. Patients are indicated for a surgical approach if the pain is not relieved after six months of physical therapy. Medication is provided to relieve pain. Healthcare providers may suggest Aspirin, Acetaminophen, Ibuprofen, or muscle relaxants to relieve pain.
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Open Surgical Approach: The surgical approach is indicated in thoracic outlet syndrome's arterial or venous form. The main goal of the surgical approach is to decompress the region or remove the cervical rib.
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Transaxillary: This shows a high complication and recurrence rate compared to other approaches. However, this procedure has a cosmetic advantage.
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Supraclavicular: It is the most commonly used surgical approach for first rib resection. In this procedure, all the abnormal anatomic structures can be resolved safely. The risk of damage to vascular structures is minimal, and the brachial plexus can be adequately visualized.
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Infraclavicular: This approach is performed individually or with other procedures to access distal subclavian vessels. The procedure helps treat thoracic outlet syndrome caused by trauma, tumor, or brachial plexus entrapment.
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Posterior: The use of this technique has been reduced in recent years. It is a highly invasive procedure with extensive muscle dissection.
What Are the Complications of the Surgical Approach in Thoracic Outlet Syndrome?
Open surgical methods such as trans-axillary, supraclavicular, infraclavicular, and transthoracic approaches have high rates of complication or recurrence. Commonly associated complications are pneumothorax (collapsed lung), infections, vascular injuries, neural damage, complete or temporary paralysis, injuries to a subclavian artery or vein, thrombosis (blood clot block vessels) of the axillary artery, hemothorax (blood collected in pleural space), chylothorax (accumulation of lymph formed in the digestive system in pleural space), autonomic dysfunction (abnormalities in nerve controlling non-voluntary functions like breathing or heart rate), or death.
What Is the Minimally Invasive Approach to Treat Thoracic Outlet Syndrome?
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Minimally Invasive Spinal Surgery: It includes the procedure starting at the spine followed by the involvement of lateral and ventral areas of the spine. An incision of less than 0.78 inches can avoid neurovascular structures that can be damaged in other procedures. This approach is helpful in cervical rib, first rib, scalene muscle (group of three muscles in lateral neck) sectioning, or resection. These anatomical structures are present behind the brachial plexus or other major vessels. This approach has no medical or surgical complications, and patients heal well.
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VATS (Video-Assisted Thoracoscopic Surgery) First Rib Resection: An intrathoracic approach is used to access the first rib. Instruments like an endoscopic drill with a video-assisted thoracoscope (instrument to examine the inside of the chest) are used. The procedure is minimally invasive and safe. A bone cutter or endoscopic rib cutter is used for first rib resection. Three ports are created in the thoracic region to conduct operations. One of the ports is enlarged for rib cutting. The advantages of this procedure include good visualization of the thoracic outlet, a highly cosmetic procedure, reduced pain, and faster healing. The procedure's limitations include the inability to perform splenectomy (a division of the anterior part of scalene muscle and rib resection), and bleeding can hamper the procedure.
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Robotic First Rib Resection: It is a complex procedure combined with VATS procedures. A four-arm robot is used for initial dissection. The rib resection is completed with a VATS procedure followed by surgery completion with a robotic arm.
Conclusion
Thoracic outlet syndrome is a condition that develops with the compression of blood vessels or nerves present between the collarbone and the first rib. It can lead to pain in the chest, neck, and shoulders. The condition can develop due to congenital anomalies, tumors, trauma, or injury. The open surgical approach to treating the disease is associated with increased complications and morbidity. Studies are ongoing for minimally invasive procedures to reduce these limitations.
