I have looked after a few kids who needed to have what is called a Nuss Procedure to fix this - but that doesn't happen to all kiddos, in fact my cousin had this, and she is fine now - her GP advised her to take up swimming, and you wouldn't even notice it now.

The only real thing I think that you could be concerned about at the moment is his breathing. If he gets unwell, you should get him checked out, but other than that it doesn't cause too many problems for most kiddos.

Let us know how you get on!