Botulinum toxin type A improves blood flow in vascular thoracic outlet syndrome.

A 28-yr-old man, diagnosed with vascular thoracic outlet syndrome, had his right anterior scalene muscle injected with botulinum toxin type A under ultrasound guidance. Subclavian artery flow rates were measured with Doppler ultrasound before and 3 wks after the injection. At 3 wks, symptoms had improved.