A prosthesis includes a radially expansible scaffold in at least two circumferential anchors extending from the scaffold. The prosthesis is placed across an os between a main body lumen and a branch lumen. The scaffold is expanded within the branch lumen and the circumferential anchors deformed outwardly to conform to the wall of the main body lumen. Optionally, a second prosthesis may be placed within the main body lumen after the first prosthesis has been deployed.
