Patent ID: 9526562
Filing Date: 2016-12-27
CPC Classification: A61B

Claim Text:
1. A high-frequency treatment tool comprising: a long, thin cylindrical sheath that is inserted into a body; an electrode member that is disposed so that the electrode member can be freely made to protrude and be retracted with respect to a distal-end portion of the sheath and to which a high-frequency current is supplied; and a liquid-feeding unit for feeding a liquid toward a distal-end side of the sheath from a base-end side thereof inside a flow channel formed along a longitudinal axis of the sheath, wherein a distal end of the electrode member is provided with a distal-end expanded portion that extends radially outward in a radiating manner, that has a base-end surface that is made to protrude and be retracted in the longitudinal axial direction with respect to the distal-end portion of the sheath, and that is formed of a conductive material, wherein the sheath is provided with: wherein a portion of the flow channel is formed between the groove and the electrode member, which is disposed so as to allow insertion thereof into the sliding hole, wherein, in a state in which the distal-end expanded portion is accommodated in the accommodating portion and the movement toward the base-end side is restricted by the restricting portion, by setting a thickness of the distal-end expanded portion from the base end thereof to the distal end thereof to be greater than a depth of the accommodating portion, a portion of the distal-end expanded portion on the distal-end side thereof is made to protrude from the accommodating portion, and an opening of a ring-shaped release port for releasing the liquid, which is formed between the outer circumferential surface of the distal-end expanded portion and the inner circumferential surface of the accommodating portion, is positioned farther on the base-end side than the distal end of the distal-end expanded portion, a portion of the groove on the radially inner side is closed by the distal-end expanded portion, and a portion thereof on the radially outer side is exposed without being closed, a liquid fed through the radially inner side of the groove collides with the base-end surface of the distal-end expanded portion and is made to flow radially outward, and the liquid that has collided with the base-end surface of the distal-end expanded portion and that has flowed radially outward collides with the inner circumferential surface of the accommodating portion, thus restoring the flow direction of the liquid to the longitudinal axial direction, and the liquid in which the flow direction thereof has been restored is assisted by a liquid fed through the radially outer side of the groove to flow forward in the longitudinal axial direction, and is released outside the sheath through the release port farther on the base-end side than the distal end of the distal-end expanded portion.