Abstract: Catheter assembly for passing an occlusion in a vessel, having a catheter hub; a hollow flexible shaft extending between the catheter hub and an open distal end; and a cutting wire provided inside the shaft, the cutting wire extending from the catheter hub to the distal end. The shaft has a cannula lumen with a cannula opening at the distal end, the cannula lumen being configured to guide a cannula. The catheter hub has a handle, which is configured to operate selectively in a cutting wire mode and in a cannula mode, and a blocking mechanism, configured to block the cannula from extending from the cannula opening while the cutting wire sticks out from the distal end.