Definition
Compression of neurovascular structures as they traverse the thoracic outlet
Types
| Neurogenic | Venous | Arterial |
|---|---|---|
|
Brachial plexus
|
Subclavian vein | Subclavian artery |
| Lower trunk - C8/T1 |
Subacute and chronic vein thrombosis Paget-Schroetter syndrome |
Reduction in pulse with arm above shoulder height Associated with cervical rib |
| 95% | 4% | 1% |
Etiology
Association with trauma / neck hyperextension
| Bony | Ligamentous | Muscle |
|---|---|---|
|
Cervical rib 1st rib Clavicle fracture malunion |
Fibrous band between cervical rib and 1st rib |
Abnormal insertion or origin of anterior or medial scalene muscles Scalene hypertrophy Scalene minimus |
Anatomy
3 components of the thoracic outlet
| Scalene triangle | Costoclavicular space | Infra-clavicular space |
|---|---|---|
|
Anterior: anterior scalene Posterior: middle scalene Inferior: 1st rib |
Anterior: clavicle Posteromedial: 1st rib Posterolateral: Upper scapula |
Anterior: Pectoralis minor Posterior: 2 - 4 ribs Superior: coracoid |
|
Brachial plexus trunks Subclavian artery |
Brachial plexus divisions Subclavian artery and vein |
Brachial plexus cords Axillary artery and vein |
Clinical
Neurogenic TOS
- intermittent suprascapular and neck pain
- radiating to medial arm & forearm
- with activities - overhead use / carrying weight
Venous TOS
- Paget–Schroetter syndrome
- swelling / venous engorgement / pain / heaviness with arm abduction
- can present with venous thrombosis
Arterial TOS
- pain and weakness + reduced pulse with arm abduction
- some patients present with thrombosis and vascular compromise
- typically seen in association with cervical rib
Provocative tests
| Elevated Arm Stress Test (EAST) | Adson Manoeuvre | Upper limb tension test |
|---|---|---|
|
Shoulder abducted 90° / ER / elbows at 90° Hands clasped / unclasped for 3min |
Head toward side tested, neck extended Arm extended Patient inhales deeply |
Arms abducted Straight elbow Wrist dorsiflexion |
|
Pain / recreation of symptoms Reduced pulse |
Pain / recreation of symptoms Reduced pulse |
Pain / recreation of symptoms Reduced pulse |
Chest Xray
Cervical rib / clavicle fractures
CT
Cervical rib / clavicle fractures
MRI
Brachial plexus - fibrous band
Neck - exclude disc pathology
Duplex ultrasound with dynamic movement
Vascular compression
Angiogram / Venography
Arm abducted and by side - compression of subclavian vein
NCS
Exclude carpal tunnel / cubital tunnel / other cause of compression
Nonoperative management
Botox
- RCT of botox v saline injection in 38 patients
- injection into scalene muscle
- no difference in pain or functional outcomes
Operative management
Options
Resection of cervical rib
Resection first rib
Scalene muscle release / scalenotomy
+/- Pectoralis minor release
Techniques
Neurogenic TOS
- complete first rib resection and scalenotomy
- typically via trans-axillary approach
Arterial TOS
- resection of cervical rib / first rib / fibrous bands
- explore and release subclavian artery
- typically via supraclavicular approach
Vumedi arthroscopic release of pectoralis minor for TOS video
Results neurogenic TOS
Rib resection
Sheth et al J Neurosurg Spine 2005
- RCT of 55 patients with neurogenic TOS
- excluded patients with cervical rib and vascular TOS
- trans-axillary first rib resection versus supraclavicular neuroplasty of brachial plexus
- better results with first rib resection
Kakamad et al Updates Surg 2025
- RCT of 48 patients with neurogenic TOS
- first rib resection versus first rib avulsion
- no difference in outcome
- first rib resection: 87% satisfied
- first rib avulsion: 92% satisfied
Scalenotomy alone
Ruoposa et al Scand J Surg 2025
- systematic review of rib sparing surgery for neurogenic TOS
- 71% good or excellent results