A rotational ablation atherectomy device including a flexible drive shaft
and a compressible burr that may be inserted and extracted from a patient
using a catheter having a diameter that is smaller than the operational
diameter of the burr. In one embodiment, the burr includes a nose portion
coupled to the drive shaft and one or more flexible abrasive disks
disposed rearwardly from the nose portion. The flexible disks are foldable
to be slidably received within a catheter. In another embodiment, the burr
includes a support member coupled to the drive shaft, the support member
having a resilient panel that spirals outwardly, forming a generally
cylindrical ablation surface. The flexible panel can be elastically urged
toward the support member and slidably inserted into the catheter. In a
third embodiment, the burr includes a plurality of struts that are coupled
to the drive shaft. An elastically compressible body disposed between the
struts permits the struts to flex inwardly to reduce the burr diameter. In
another embodiment, the burr includes a plurality of flexible wires
attached at proximal and distal ends to the drive shaft. An abrasive
sheath is disposed over the wires. The wires can be bent inwardly to
compress the burr and re-expanded by rotation of the burr. In another
embodiment, the burr comprises a nose portion and a resilient shell having
a compressible, larger diameter abrasive section disposed at the proximal
end of the nose portion.
