hi

You've come to the right place for advice as there are so many people here with lots of experience.

I know that somewhere on the forum (maybe in the general info ?) there is a helpful diagram of the thoracic outlet which explains how close everything is in the thoracic outlet. The subclavian vein runs in the area and if it gets squashed when the space is narrowed, you can get significant symptoms. The severely elevated velocities bit is referring to how narrowed the vein is - and those numbers are high ie. the vein is quite narrow. The doctors might also get concerned that as the vein is narrow, you can be at increased risk of getting a clot in the vein as the blood supply is sluggish.

You say that you've been having trouble with your arm but it might help to know what symptoms you've been having. You may need surgery but most of us have tried specific physio first to try to open the space up. Your doctor definitely needs to refer you to a specialist vascular surgeon who can talk through all your options and they may want to do some imaging rather than just relying on ultrasound. I had to have a special kind of angiogram rather than MRI scan but UK and US are different in many ways!

hope this helps a bit - I had months of scary symptoms without a diagnosis and I remember how hard it was....I didn't find this forum till afterwards but wish I'd found it earlier.

Take care

Jenny