Described herein are guidewire positioning and support devices, method for using them, method of treating a subject using them, and systems including such guidewire positioning and support devices. These devices typically include a rotatable distal tip region that may include one or more wedges. The wedges may be extendable from the rotatable distal tip. The distal end of the device may be steerable, and may be steered while still rotating the distal end of the device. The wedges (which may include sharp forward-cutting blades and blunt lateral portions) can be extended from the distal housing and locked in any position (extended, partially extended or retracted) and rotated clockwise and/or counterclockwise while locked in a retracted, extended or partially extended position. The distal region of the device may also be controllable steered from the proximal end of the device. Systems including these guidewire support catheters are also described, as are method of using them, including methods of treating chronic total occlusions.
