[Clinical, flowmetric and radiologic study of the thoracic outlet in 95 healthy subjects: physiologic limitations and practical impact].

Ninety-five healthy subjects have been examined regarding the presence of symptomatic compression of the brachial plexus and subclavian vessels (Thoracic Outlet Syndrome: TOS). Each subject was examined clinically and by Doppler flowmetry during performance of Adson, hyperabduction and abduction-external-rotation manoeuvres. In all subjects Roos test and X-ray examinations of the cervical spine and thoracic aperture were performed. The response was considered positive when the radial pulse disappeared for the clinical test, and when the flow was totally arrested for the Doppler flowmetry. Adson's manoeuvre showed a 1% clinical positive response and a 0% doppler positive response. Hyperabduction at 45 degrees showed a 0% positive response both clinically and by Doppler flowmetry; at 90 degrees, it showed positive response of 6% and 1% respectively, and at 180 degrees it showed positive responses of 40% and 11%. Abduction-external-rotation manoeuvres showed 14% clinical and 7% Doppler positive responses. The Roos test was positive for 8% of the subjects and X-ray was abnormal for 13% of the subjects. We conclude that: Doppler flowmetry is useful for the TOS diagnosis only when the clinical evaluation is abnormal. Total arrest of flow is sometimes temporary; arterial flow must be examined at least 20 seconds. Total arrest of flow is never seen during Adson manoeuvre or hyperabduction at 45 degrees or 90 degrees in healthy subjects. Clinical or Doppler perturbation is not significantly higher for healthy subjects presenting an X-ray abnormality.