Can multiple types of TOS occur in the same patient?
Yes, one patient can have multiple types of TOS at the same time. As shown above, the artery, vein, and brachial plexus pass through each thoracic outlet together. Furthermore, the mechanism of compression is similar for all types of TOS. Thus, a patient can have compression of 1, 2, or all 3 of these vital structures. In fact, many patients with neurogenic TOS have significant compression of the subclavian vein, but without a blood clot. Since this compression impairs venous drainage of the arm, swelling or edema of the arm can result. As a result, compression of the brachial plexus is magnified. In that case, treatment to relieve the venous compression helps relieve compression on the brachial plexus.
It is often difficult for a physician to distinguish these multiple compression effects. Therefore, modern imaging quite often provides this important additional information prior to treatment.