Thoracic Outlet Syndrome Testing
Thoracic Outlet Syndrome (TOS) occurs when the nerves or blood vessels passing through the thoracic outlet — the narrow corridor between the neck and the arm — become compressed. The VasoGuard's physiologic testing tracks blood-flow and waveform changes across provocative arm positions to pinpoint the vascular component of TOS and support the broader clinical workup.
TOS is a condition caused by compression of the brachial plexus nerves and/or subclavian vessels as they pass through the thoracic outlet. Symptoms may include pain, numbness, and impaired blood flow to the arm and hand.
- Can be neurogenic, venous, or arterial in origin
- Often triggered by certain arm positions or activities
- Requires specialized vascular testing for diagnosis
TOS testing records blood-flow and waveform changes in the arm as it is moved through provocative positions. Blood pressure cuffs, Doppler, and PPG sensors detect the changes in circulation and waveform patterns that indicate vascular compression.
- Provocative maneuvers — Adson's, costoclavicular (military brace), and graded arm elevation
- Real-time monitoring of blood flow and waveforms
- Automated data capture and analysis
TOS testing is invaluable for:
- Diagnosing vascular and neurogenic TOS
- Guiding surgical and non-surgical treatment
- Monitoring post-intervention outcomes
- Supporting early intervention and improved quality of life
These tests are recommended in clinical guidelines for comprehensive vascular assessment and are a mainstay in vascular labs.
VasoGuard systems streamline TOS testing with automated workflows, high-precision sensors, and intuitive software. Clinicians benefit from real-time data, comprehensive reporting, and seamless integration with EMR systems.
- Automated multi-site measurement
- High-resolution waveform display
- Comprehensive data management and export
The provocative sequence
Ten positions that reveal hidden compression
VasoGuard records the arterial flow waveform as the arm is moved through each provocative position. Comparing the resting trace against the stressed positions reveals where circulation is pinched — the hallmark of the vascular component of thoracic outlet syndrome.
Rest
Baseline — arms relaxed at the sides
Hands Up
Both arms raised, elbows bent to 90°
Hands Up 180°
Arms extended fully overhead
Hands 90° Front
Arms reached forward at shoulder height
Hands 90° Sides
Arms opened out to the sides at shoulder height
Adson Right
Head rotated to the right, chin lifted
Adson Left
Head rotated to the left, chin lifted
Costoclavicular
Shoulders drawn down and back — the military brace
Allen Right
Right arm raised, head turned away
Allen Left
Left arm raised, head turned away
The full VasoGuard protocol also captures a symptomatic position and a graded elevation stress, recording heart rate, waveform amplitude, and rise time at every step for side-by-side comparison.