It must have hurt. Ouch. My first ballooning on the first procedure was the worse, and it was because my one sorta-working jugular was blocked by the balloon and the other jugular had a complete valve blockage, so there was head pressure as well as neck pain, and that was on the Fentanyl. No, you don't want the valve to 'pop' with a popping sound as in tearing. But you do want it to stay open. Yes, 20 mm is large!!
If you can later get us information on what size balloon was used and what atm, it would be good to know if you were fully treated, or if there was undertreatment, which might be possible with a vein that large. You're at the top of the sizing chart. But that is getting so technical and what I really want to do is wish you well, and rest. Even with no immediate improvement, which is really disappointing even to me hearing about it, it is still good to have improved blood flow. Take care.
I don't have all the info yet. They are supposed to mail a CD to me.
Anyway I think he used a 16mm balloon. In the image he showed me, the ballon appeared to be fully inflated with no apparent waist. I think that's good. I would like to have seen him get to 18 mm but going from 3 to 16 is quite a stretch. I suppose it shrank back to 12 as the balloon was deflated. As the ballon was inflated I felt great pain in the area of the balloon but it also felt like my head was exploding. I guess that's the same feeling you had. Definitely not something I would recommend for entertainment.
That makes me think of something. Some IRs say that if you treat the valve then other problems higher up tend to disappear. So maybe when you completely block blood flow at the valve, blood still comes into the vein from above which increases the pressure there. That stretches out the vein. It's kind of like doing a venoplasty with blood pressure instead of a balloon.