Dr. Cumming was just saying that it isn't even agreed-upon what qualifies as a restenosis.
The imaging to determine restenosis, which would be doppler imaging, is imperfect and might only be accurate 80% of the time.
Dr. Zamboni saw restenosis in 50% of patients at 18 months. Dr. Mehta presented an abstract on his trial and he saw 8% restenosis at 4 months. Dr. Cumming commented on that, that it seemed like a low figure for restenosis.
My own personal experience was that my right jugular has stayed open but my left jugular partially restenosed, to 70% closed. It had originally been 99% closed, so that was still an improvement, and it's my "little" jugular that's a third the size of my right so it is not the workhorse of my two jugulars, but Dr. Sclafani was able to get it opened again, and it seems to have stayed open this time.
I would expect restenosis rates to be different for valves than for hypoplasias or septums or webs. There are different types of restenosis, from garden-variety recoil stenosis to complications such as clotting, scarring, vein remodeling, intimal hyperplasia. If a vein is treated with too-small of a balloon, it would be much more likely to restenose. Sizing with IVUS is a way for the IR to precisely choose the balloon, neither too small to do the job nor too big that might cause injury. I agree with MarkW and I also think that, as research continues, we'll start to see some actual figures such as Dr. Mehta's.
I love gardenias. They were my wedding flowers.