I know a couple of stories like that from 15 years ago, I assume the risk is lower nowadays. Back then it was a risk, just like a colon fistula. If it is a fistula, they can probably be closed, but it can be a lot of effort - I know colon-vaginal fistulas cannot always be closed or sometimes it takes a very long time. I had one of those and it took almost half a year for it to completely heal.
Incontinence can have several origins. It can be a fistula, but more likely it is a weakening of the muscles in the lower belly. A suregeon might cut a muscle or nerves controlling muscles, so some people cannot "hold" the pee anymore. I know of about 2 or 3 cases like that who had surgery in the past 5 years. They sadly have to rely on incontinence products. Another possibility is a weakening of the muscles by the surgery - or a weakening of the muscles by hormone therapy. In that case you have no permanent flow but just are more likely to loose some drops or have to run to the loo more often (not a good thing if you are in the wrong state nowadays, I guess). The latter is what is affecting me now. I had the surgery a long time ago, but probably due to a deficient hormone therapy and maybe some late surgical effects, I just am a bit weak there and prefer to be not too far from a bathroom - or I just drink less when I know I want to go to the cinema and have to sit for 2 hours. Its not really bad though - Other women in my age group can develop this too.
I do not think 19% is accurate. I would think maybe 1% or less for the severe version any maybe a bit more for a mild version. Where do these numbers come from?