Hi and welcome to HCM..
Thank you for posting your query.
I read your question completely and have understood it well..
I being a surgeon, we come across many such cases.
I am really sorry that your child had to undergo
diaphragmatic hernia surgery at such a small age.
But, I suggest you not to worry.
Sir, these mild pelvicalyceal enlargement or fullness that you mentioned has absolutely no clinical significance.
It is seen in early infancy in almost all children and gradually will subside as the child begins to grow..
I suggest you these things.
1. Do not worry about that
kidney thing..
2. In fact, just forget it. Don't bother for another scan or something atleast for some 5 years!
3. Diaphragmatic surgery is unrelated to this kidney problem, so chill..
Your child will be fine.. Do not worry..
Take care and God bless you..
In case you need any further assistance, let me know. I will be there for you..