I'm sorry about your pup.
Liver shunt is very common in Yorkies as is microvascular dysplasia (small shunting throughout the liver). That bile acid number is quite high but not extreme. Did the vet do a pre meal and post meal bile acids blood draw?
It is good that your vet did all of this first because the anesthetic protocol for future surgeries will need to be altered to protect him.
Do you have the blood panel results?
Does he have any symptoms like shaking, seizures, drooling, gi upset, lethargy, picky eating, urinary issues, walking into walls, etc.?