Use this to treat diabetes type one, do a pancreas transplant and replace the immune system so it does not reject the transplant.
They are unlikely to do it if the disease can be controlled with an insulin pump, which is far less invasive. Insulin pumps are far from perfect solutions. (Somebody close to me has one and I can observe what a massive pain in the ass it is, among other places.) But surgery like this is going to have to come a long way before it's routine enough to replace a therapy that is aggravating but sufficient.