A cutting operation is performed with an apparatus having an elongated sleevewith aport in its distal section. The sleeve is connected to a vacuum source and arotating shaft isdisposed in the lumen of the sleeve. The shaft has a cutting blade at itsdistal end opposite theport. The blade has two cutting edges, a gear assembly operative toalternately rotate the shaftin a first direction and a second direction about the axis of symmetry of theshaft, and a motorfor powering the gear assembly.
