[Thoracic outlet syndrome. Value of non-invasive arterial studies]

The value of non-invasive clinical evaluation of arterial compression at thoracic outlet was evaluated in 150 normal subjects and in 103 patients operated upon (127 sides). The specificity of arm abduction manoeuvres was good for angles of 90 degrees or less. Their sensitivity was poor in forms with neurological symptoms and better in forms with vascular symptoms. In these two forms, their predictive value was excellent (congruent 90%) with angles of less than 90 degrees. Their negative predictive value was mediocre in forms with neurological symptoms. It is concluded that a positive response to manoeuvres at an angle of less than 90 degrees is a strong argument in favour of arterial compression in the thoracic outlet, but that a negative response should not rule out a diagnosis of thoracic outlet syndrome, especially when neurological symptoms are present.