Abstract: A cutter for a blood vessel tissue harvesting instrument is disposed at the distal end of an insertion member. A cutter body projecting from the distal end of the insertion member includes a slit that extends from the distal end toward a base edge. High-frequency electrodes are disposed along the sides of the slit. A feeding mechanism has rotating surfaces which are rotated as a result of being pressed by the tissue, and which feed the tissue toward the base edge of the slit. The rotating surfaces are provided by two rotary members disposed opposite each other along the two side edges of the slit, respectively, so that the first and second rotating surfaces move in a direction from the opening of the slit toward the base edge of the slit.

Abstract: The body tissue harvesting instrument is provided with a cutter which is disposed at the distal end of an insertion member that is inserted into the body of an organism, and which severs tissue inside the body. The cutter includes: a cutter body which projects from the distal end, and which includes a slit that extends from the distal end toward the base end; a first high-frequency electrode disposed along the two side edges of the slit on the outer surface of the cutter body and a second high-frequency electrode disposed at the base end of the slit; and a mechanism which is disposed on both sides of the distal end of the slit in the projection of the cutter body, which rotates as a result of being pressed by the tissue, and which feeds the tissue toward the interior of the slit. In addition, the parts located on both sides of the distal end of the slit in the projection mutually separate in the thickness direction of the slit.