In order to create a stent, which despite being simple to guide in the relevant body conduit allows flexible adaptability to the body conduit in a simple manner while avoiding undesirably high expansion forces on the wall of the body conduit, in accordance with the invention a catheter is provided, with an essentially tubular filling area surrounding the part of the catheter which can be introduced into the body conduit, which can be filled with a plastic mass which forms the stent by a process of hardening there is provision for positioning the filling area at the position intended for the stent in the body conduit, for hardening the plastic mass in the filling area, for creating the stent and for removing the catheter from the body conduit with the stent remaining in the body conduit.
