Yes I did watch her entire course but that was months ago when I was going to get her spayed but then she got a waiver. Maybe I will watch it again now that I am further along on my learning curve and will hear things I missed before. The online groups were saying even if they leave the smallest bit of uterine tissue it could cause pyo. This specialty hospital though said they only do 3-4 a month but it is catching on more. So that is really not a lot... It would be ideal to have a surgeon who does them daily and could do them with his eyes closed, like my thyroid surgeon claimed he could do which is why I ultimately picked him--oh yeah, and the line that he took his mother's thyroid out!!!Stump pyometra occurs only if enough of the uterus remains. However, as Ginny says, this should not be a problem if a surgical specialist does the OSS.
Have you watched Dr. Sara's great course on neutering that dives deep into these details?