Patient Presentation
Within the span of one week, a pediatrician encountered two teenage females who had come to clinic for other problems but who had the diagnosis of thoracic outlet syndrome. One had already had surgery and the other was planned within the next month. He thought this was unusual and didn’t remember seeing anyone with this problem for several years. He decided to review the problem.
Figure 141 – MRA with contrast of the chest performed via a right forearm injection with the arms in a neutral (adducted) position (above) shows a normal appearance to the subclavian arteries. MRA was then performed with the arms in a raised (abducted) position (below) which shows development of a moderate stenosis in the proximal left subclavian artery.
The diagnosis was left arterial thoracic outlet syndrome.
Discussion
Thoracic outlet syndrome (TOS) is a problem where the neurovascular bundle becomes compressed in one of three areas of the thoracic-cervico-axillary area.
These are:
- Interscalene triangle – “…formed by the anterior scalene muscle anterior, middle scalene muscle posterior and the first rib inferiorly.” Through the triangle runs the subclavian artery and the roots and trunks of the brachial plexus. The subclavian vein is outside the triangle anterior to the anterior scale muscle.
- Costoclavicular space – “…bounded superiorly by the clavicle, anteriorly by the subclavius muscle and posterior by the first rib and middle scalene muscle.” The subclavian artery, vein and brachial plexus run through this space.
- Retropectoralis minor space – “…bounded anteriorly by the pectoralis minor muscle and posteriorly the subscapularis muscle and chest wall.” Again the subclavian artery, vein and brachial plexus run through this space. Least common location for the 3 areas.
Overall TOS occurs mainly in patients 20-40 years old but can occur in any age including one patient who was 4 months old. It is more common in females.
There are four types of compression:
- Neurogenic compression
- Most common cause in adults (95%) and children (~75%)
- Equally common in costoclavicular and interscalene locations
- Clinical: “pain, paresthesia and weakness in hand, arm and should. Neck pain. Raynaud’s phenomenon….” Can also have pain in chest or occipital headache. If chronic can present with muscle atrophy.
- Cause: Space constraints such as muscle hypertrophy, trauma or accessory muscles.
- Arterial compression
- Most frequent in costoclavicular location followed by interscalene
- Clinical: “Weakness, cold and pain in the upper limbs. Signs of ischemic insufficiency like claudication, pallor, paresthesia.” The shoulder and neck are usually not involved.
Venous compression
- Most frequent in costoclavicular location
- Clinical: “Swelling, pain, cyanosis of extremity, distention and prominence of veins in the arm and over the shoulder.”
- Seen with excessive upper extremity activity possibly due to repetitive trauma to the vessels
- Mixed
- More than one type of compression
Problems associated with TOS include:
- Neurological problems including pain and paresthesia
- Vascular stenosis or aneurysm
- Ischemia of the limb
- Vascular thrombosis including emboli
Overall causes of thoracic outlet syndrome include:
- Ribs, cervical and first rib anomalies – most common cause in children
- Muscle – hypertrophy, trauma, accessory
- Vascular – aneurysm
- Tumor or other space occupying lesion
Learning Point
The diagnosis can be difficult because of the intermittent and unusual symptoms including pain, weakness, and skin changes. On the physical examination, lateral difference of the blood pressure may indicate compression. There are a variety of provocative maneuvers which can be completed to help establish a diagnosis. These include putting the body into different positions and noting changes in pain, paresthesia, coloration and pulses. They can be helpful but are not diagnostic for all patients. Selmonosky diagnostic triad is felt to be one of the most sensitive tests and includes “weakness on abduction, adduction or opposition of the fifth finger, plus the presence of paresthesia, fatigue, or numbness with or without paleness of the hand when elevating the arm, plus sensitivity of the supraclavicular area to mechanical compression.”
Imaging may include ultrasound, computed tomography or magnetic resonance imaging depending on the patient age and circumstances. MRI is often used as it can evaluate soft tissue, bone, neural and vascular structures. Angiography and/or venography may be considered as well. Other testing can include nerve conduction tests or electromyography studies.
Treatment usually begins conservatively including education, lifestyle changes such as postural improvements and physical therapy. Around 60% of patients respond to conservative treatment. For vascular TOS angioplasty, balloon dilatation, thrombectomy, anticoagulation etc. may be needed. For neurogenic compression, nerve block may be one option. Surgical intervention is used when more conservative treatments are not working. Bone resection of ribs (cervical or first) and/or removal or debulking of anterior scalenus muscle are common procedures. Roos procedure is one of the most common and includes resection of the lateral aspect of first rib and anterior scalene muscle. Overall long-term success rate reported is good at 75-90% and is better for arterial or venous causes. Neurological causes also have a clear benefit but not at the rate of vascular causes. Recurrence can occur and also presentations on the contralateral side after operation have also been noted.
Questions for Further Discussion
1. What is Raynaud’s phenomenon and how is it diagnosed?
2. What are common neonatal brachial plexus injuries and what are their outcomes?
3. What are common overuse injuries in sports and how could they be mistaken for TOS?
Related Cases
- Disease: Thoracic Outlet Syndrome
- Symptom/Presentation: Pain
- Specialty: Neurology / Neurosurgery | Orthopaedic Surgery and Sports Medicine | Radiology / Nuclear Medicine / Radiation Oncology
- Age:Teenager
To Learn More
To view pediatric review articles on this topic from the past year check PubMed.
Evidence-based medicine information on this topic can be found at SearchingPediatrics.com and the Cochrane Database of Systematic Reviews.
Information prescriptions for patients can be found at MedlinePlus for these topics: Thoracic Outlet Syndrome and Chest Injuries and Disorders.
To view current news articles on this topic check Google News.
To view images related to this topic check Google Images.
To view videos related to this topic check YouTube Videos.
Chavhan GB, Batmanabane V, Muthusami P, Towbin AJ, Borschel GH. MRI of thoracic outlet syndrome in children. Pediatr Radiol. 2017;47(10):1222-1234. doi:10.1007/s00247-017-3854-5
Boglione M, Ortíz R, Teplisky D, et al. Surgical treatment of thoracic outlet syndrome in pediatrics. Journal of Pediatric Surgery. 2022;57(9):29-33. doi:10.1016/j.jpedsurg.2021.08.017
Khoury MK, Thornton MA, Dua A. Systematic review of intermediate and long-term results of thoracic outlet decompression. Seminars in Vascular Surgery. 2024;37(1):90-97. doi:10.1053/j.semvascsurg.2024.01.001
Author
Donna M. D’Alessandro, MD
Professor of Pediatrics, University of Iowa