An ultrasonic device having a tri-axial configuration including an ultrasound transmission member, a dilator, and a sheath is disclosed. The ultrasound device may be used in a procedure to treat an occluded blood vessel. The ultrasound transmission member can transmit ultrasonic energy from an ultrasonic transmission member into the subintimal space of a blood vessel. The sheath may articulate to aid in the process of re-entering the central lumen of the blood vessel.
