A method and apparatus of treating tissue adjacent to a bodily conduit using thermotherapy, while preventing obstructions of the bodily conduit due to edema employs the circulation of warmed fluid to maintain the temperature of the bodily conduit walls and compresses the tissue to be treated to increase the effectiveness of the irradiated heat. An energy-emitting source containing catheter is inserted in a bodily conduit and is positioned in a region of the tissue to be treated so that the energy-emitting source radiates energy to the tissue to be treated. Fluid warmed to over 30° C. is circulated into and through the catheter to warm walls of the bodily conduit adjacent the catheter. The circulated fluid inflates a balloon to a pressure to compress the tissue to be treated. The combination of warmed fluid over 30° C. being circulated adjacent the bodily conduit to maintain the warmth in its walls and the compression of the tissue to be treated enables a natural stent to be formed that remains after the catheter and compression balloon is removed.