Ureterovaginal fistula should best be treated by:
Surgeries for ureteric fistula:

Bladder flap procedure (modified Boari-Ocker-Blad)
Ureteroneocystostomy
Implantation into the bladder
Note: End to end anastomosis may lead to stricture formation.
Colonic transplantation results in recurrent pyelonephritis and hyperchloremic acidosis.
Ureteroneocystostomy
End-to-end anastomosis through an ureteric catheter
Implantation into colon
Heal conduit