A method for operating an ultrasonic reentry device, includes: providing an ultrasound transmission member having a proximal end and a distal end； providing a catheter body having a lumen surrounding the ultrasound transmission member； providing a dilator slidably disposed within the lumen of the catheter body, the dilator surrounding the ultrasound transmission member； and exposing the distal end of the ultrasound transmission member from a distal end of the dilator.
