A guidewire apparatus for use during percutaneous catheter interventions
such as angioplasty or stent deployment. A protection element comprising a
filter or an occluder is mounted near the distal end of a steerable
guidewire, which guides a therapeutic catheter. The guidewire apparatus
comprises a hollow shaft movably disposed about a core wire. The shaft and
core wire control relative displacement of the ends of the protection
element, causing transformation of the protection element between a
deployed configuration and a collapsed configuration. The protection
element is freely rotatable about the guidewire apparatus. A tracking
member disposed adjacent the distal end of the guidewire apparatus can be
used to guide the device along another guidewire. Thrust bearings may be
employed to facilitate unlimited rotation of the steerable guidewire
within the protection element, especially while the protection element is
retained in the collapsed configuration.