why remove the biliary stent?

My mother was diagnosed about a month ago with biliary and possibly pancreatic cancer. Because of her bad condition at the time she went into the hospital, they inserted a biliary stent, by way of her esophagus (forgetting the proper term right now). It worked well and she is now stable.

The doctors have not been very forthcoming with information to my mother and sister (they live a bit away and I am not there for doctor visits, etc). Anyway, mother is now home and there is no chemo or actual surgery planned yet if any will be. But they want her to come in later this week to have the stent removed. She says she doesn’t want that unless they give her a GOOD reason for removing it. Says…its working, why remove it? She is afraid she will just get in the bad condition again if they remove it. Only thing I have found that might relate is that maybe the stent might be prone to infection if left in. Any other “common knowledge” reason for them wanting to remove it? Of course, she needs to ask the doctors, but hoping we can get some info before then if possible, so she can understand their reasoning maybe. Thanks for input!!