Objective: The present study was undertaken to determine which factors differentiate patients with a good outcome after treatment for Thoracic Outlet Syndrome (TOS) from patients with a poor outcome.
Methods: A total of 85 patients, who were examined during one year, had at least 6 months of follow up after treatment for TOS with either surgery or botulinum chemodenervation.
Results: Socioeconomic factors of work disability or workers' compensation claims did not differentiate treatment-responsive TOS from treatment-resistant cases. There was no difference between the 2 groups regarding the presence of anomalous anatomy detected by ultrasonography or regarding the presence of subclavian artery flow acceleration or occlusion detected by duplex sonography. Several factors were noted more frequently in treatment-resistant patients: sensory complaints extending beyond lower trunk dermatomes (42% vs. 10%), weakness extending beyond lower trunk myotomes (19% vs. 2%), histories of previous non-TOS surgery of the neck or upper limbs (50% vs.17%), comorbidities of fibromyalgia or complex regional pain syndrome (81% vs. 12%), and depression (35% vs. 10%). Treatment-resistant patients complained about more widespread functional impairments on a validated Cervical Brachial Symptom Questionnaire (CBSQ) than treatment-responsive patients. Resistant cases responded less often to a scalene test block (38% vs. 100%), which is designed to simulate the effects of targeted treatment.
Conclusion: In summary, compared to patients with a good outcome after targeted treatment, patients with a poor outcome had more diffuse complaints and responded less often to a scalene test block.