When my PC was biopsied during EUS/ERCP, the surgeon inserted a Boston Scientific "Wallflex" series metal stent to relieve the blockage in my common bile duct and the jaundice/itching it was causing.

Make sure you get an implant card from the surgeon describing exactly what make/model of stent you have, and specifically its MRI compatibility. I didn't get that from my surgeon, and Boston Scientific was absolutely horrible in their multiple failures to help me when I needed that info before an MRI.

With that said, I don't know if any of these stents are considered permanent or require maintenance / replacement. I got the impression mine was mainly a 1-year stop-gap until the Whipple. I could see replacement being difficult if tissue grows around it or becomes attached to it. And go easy on your new stent for a few weeks to prevent infection!