My CT scan shows oval shaped 10.9 mm vs 4.5 mm kidney stone in the upper ureter, with a good orientation. What chances of passing?

Unlikely. 11mm stone is very unlikely to pass on its own. Hopefully you are under the care of a urologist.Good luck.
Kidney stone passage. Kidney stones that are 8mm or larger and are in the ureter close to the kidney only pass 1 out 3 times. 2 out 3 fail to pass without intervention. There are medications that can increase the odds of successfully passing a kidney stone, but only with the help of a physician can you know if this is the best course of action.