My 2nd DD had this surgery at 15 mos (she is almost 7 now). She, too, was born with a solitary kidney and had grade 5 reflux, neither problem was discovered until she was 8 mos old

Her recovery from the surgery was hard---she developed severe anemia from the blood loss, and was in quite a bit of pain for several weeks afterwards. She kept holding her urine until we had to take her to the ER to be cathed several times

It was a very difficult time. The good news is, her follow up VCUG showed the reflux was gone. For us, NOT having the surgery simply wasn't an option. If I had it to do all over again I wouldn't change a thing---DD is alive and healthy with a functioning kidney, what more could I ask for?
On the downside, DD still suffers from recurrent UTIs not related to her reflux history. She has been on prophylactic antibiotics for 5 years and will continue indefinitely. Not sure why she is so prone to them, but for now preserving her kidney function is very important so she will continue to take them to prevent future UTIs.
((((HUGS))))) Parentsplace.com used to have a great Kidney Reflux board, I am not sure if they still have one.