Verify, Verify, Verify
There really isn't a way to verify how many surgeries were performed to be honest. What you can do is look up his medical license and verify how long he has had it. You can also ask him or his team to send you a list of his credentials along with work history and then personally call and verify it yourself. That is what I did when choosing my surgeon. It can be tedious at times, but in the end I was glad that I did it because it made me confident I had found the best possible surgeon for me. Best of luck!