I'm sorry to hear about about your Yorkie with pancreatitis. My Yoda had it last year and it was very scary for us. I'm no pancreatitis expert, but basically Yorkies in general can have sensitive stomachs, and their little bodies can't handle fatty foods long-term. He was very, very weak and lethargic when he had an IV and was treated by the vet.
We have changed the diet of both of our Yorkies tremendously (never EVER any human table food), and they both eat low-fat Royal Canin Veterinary Diet (
Royal Canin Veterinary Diet Canine Low Fat LF 20) along with rice for their main meals. Treats are organic cookies which we have cleared with our vet. They've each lost a bit of weight and have been more healthy and spunky since the diet change. Yoda has been healthy since that pancreatitis episode about a year ago and hasn't had any relapses or issues with his pancreas, so there is hope with a changed diet.
Most wet foods will be higher in fat concentration than the food I mentioned above, you may want to consult with your vet to see what they recommend. A homemade diet of chicken and rice would be lower in fat than wet canned foods too.
There is also a thread about homemade Yorkie treats and recipes, which can help with diets as you know exactly what ingredients are in the treats. The thread is here:
http://www.yorkietalk.com/forums/yor...od-treats.html
Good luck!