What is venous thoracic syndrome, its symptoms, and treatment options, particularly in younger to middle-aged adults with a history of heavy lifting or repetitive arm movements?

Venous Thoracic Outlet Syndrome (VTOS)

Venous thoracic outlet syndrome is compression of the subclavian vein in the costoclavicular space that leads to chronic venous injury, stenosis, and potentially thrombosis (Paget-Schroetter syndrome), most commonly affecting young, active adults engaged in repetitive overhead activities or heavy lifting. 1, 2

Pathophysiology and Anatomical Basis

The subclavian vein becomes compressed as it passes through the costoclavicular triangle—bounded by the clavicle superiorly, the first rib inferiorly, and the anterior scalene muscle posteriorly 1. Repetitive compression causes:

• Progressive vein wall thickening and fibrosis with restrictive fibrotic tissue surrounding the vein 1
• Intimal damage resulting in luminal narrowing and a thrombogenic surface 1
• Eventually, acute thrombosis (effort thrombosis or Paget-Schroetter syndrome) in the most severe cases 3, 4

This condition represents only 4-5% of all thoracic outlet syndrome cases, with neurogenic TOS being far more common at 95% 5.

Clinical Presentation

VTOS typically presents in young, otherwise healthy patients with a history of repetitive upper extremity activity 3, 4. Key symptoms include:

• Upper extremity edema, rubor, and functional impairment from episodic venous outlet obstruction 6
• Arm swelling, heaviness, and discoloration with activity 4
• In acute thrombosis (Paget-Schroetter syndrome): sudden onset of arm swelling, pain, and cyanosis 3, 6

A critical pitfall: venous compression during arm abduction occurs in 71% of asymptomatic individuals on imaging, so clinical correlation is absolutely essential—imaging findings alone do not establish the diagnosis. 2

Diagnostic Approach

Initial Evaluation

Start with chest radiography to identify osseous abnormalities including cervical ribs, first rib anomalies, or congenital malformations that predispose to compression. 1, 2

Duplex ultrasound is the first-line imaging test, performed in both neutral position and with provocative arm maneuvers (abduction to 90 degrees), looking for flow acceleration, turbulence, and signal arrest. 2, 7

Advanced Imaging When Intervention Is Considered

• Catheter venography is the gold standard for definitive diagnosis, performed with contrast injection in both neutral and stressed (arm abducted) positions using digital subtraction acquisition 2, 3
• CT venography (CTV) obtained 120-180 seconds after IV contrast in each arm position separately, evaluating for venous compression, thrombosis, and collateral circulation 1, 2
• MR venography (MRV) with superior soft tissue contrast, performed in neutral and arms-abducted positions to assess subclavian vein narrowing, occlusion, collateral formation, and thrombus 2

True VTOS is confirmed by finding venous thrombosis and collateral circulation in both neutral and stressed positions—these represent objective findings of clinically significant compression, not just positional changes. 2

Treatment Algorithm

Acute Presentation (Paget-Schroetter Syndrome with Thrombosis)

When symptoms began less than 14 days prior—a critical timeframe that predicts outcomes—initiate catheter-directed thrombolysis (CDT) immediately for clot removal. 3, 4, 8

The treatment sequence is:

1. Catheter-directed thrombolysis for restoration of subclavian vein patency 3, 8
2. Anticoagulation maintenance for 4-6 weeks post-thrombolysis during the period of endothelial injury and inflammation 3, 6
3. Surgical decompression within 4-6 weeks after thrombolysis to address the underlying anatomical compression 3, 6

Surgical Management

Surgical decompression is indicated when conservative management fails after 3-6 months, or when there is true vascular TOS with progressive symptoms, significant functional compromise, or vascular complications. 1

The surgical procedure includes:

• First rib resection (complete removal of the entire first rib) 3, 5, 8
• Anterior and middle scalenectomy 3, 5
• Resection of subclavius muscle and costoclavicular ligament 3
• External venolysis of the subclavian vein 3, 8
• Intraoperative venography to assess for residual stenosis 3, 8
• Direct vein reconstruction if needed (patch angioplasty or bypass grafting) for intrinsic venous pathology, webs, or residual stenosis 1, 3

Multiple surgical approaches exist (transaxillary, infraclavicular, paraclavicular, supraclavicular), with the infraclavicular approach showing excellent results: 91% primary patency, 100% secondary patency, median blood loss 78 mL, and no brachial plexus or phrenic nerve injuries 8.

Post-Surgical Management

• Interval anticoagulation continuation as determined by venous reconstruction needs 3
• Comprehensive physical therapy and rehabilitation program to achieve return to full function 3
• Postoperative venography often indicated to evaluate for residual narrowing 2
• Follow-up ultrasound for vessel patency assessment 2

Critical Pitfalls to Avoid

Do not diagnose VTOS based on imaging alone—venous compression with arm abduction is present in asymptomatic individuals, and one study found 71% with unilateral compression had bilateral imaging findings but only 21% had bilateral symptoms. 2

Do not delay treatment beyond 14 days of symptom onset in acute thrombosis—this timeframe is one of the most important predictors of outcome. 4, 8

Do not perform thrombolysis without planning definitive surgical decompression—the underlying anatomical compression must be addressed to prevent recurrence and avoid indefinite anticoagulation. 3, 5

Do not overlook deeper pathology such as Pancoast tumor or cervical spondylopathy that may mimic VTOS. 2