The name of the surgery is orichopexy. In it the surgeon will move the boy's testicles to his scrotum
. The biggest difficulty in this surgery is maintaining a blood supply to the testes. The fact that your sons left testes has a good vascular flow is a good sign. But the fact that the right one has none, will lead to certain problems. A possible solution is that the surgeon cuts off certain blood vessels and reconnects them in an effort to provide a bloody supply to the testes.
Even so, I should tell you, the process isnt always successful.
As for your son's fertility
, studies have shown that boys with bilateral undescended testicles have a lower fertility rate.
I hope this helped, wish your son all the best.