HI,
Stents can not stay in place for a long time. Depending on the obstruction a stent will be replaced about every three months or sooner. If a lenghty operation is planned, you should ask if they are planning a whipple? That's a very long and complicated operation where part of the liver, the gallbladder, the bile duct, part of the stomach and sometimes also the pancreas head and part of the intestines are removed. It usually takes the patient a very long time to recover from that. But if they do, they can return to an active life. If this is the surgery that is planned, I think your relative may have klatskin, a bile duct carcinoma.
Wish you all the best