Most probably, he couldn't yell calling his guards because he was not anymore the man he used to be. No one could yell very well after that.
Remember in epis.19 Karura knew how to go in the palace using a secret passage, probably the same she used to escape in the day she hurted him.
After that, she must have spent years and years running away from him and fighting just every soldier he sent after her. Then she changed her name to Karura and her appearance, looking more a warrior than a princess.