US Patent 7749156 Retractable treatment instrument for endoscope

A retractable treatment instrument for an endoscope is provided. The retractable treatment instrument includes a flexible sheath configured such that at least a tip portion thereof is formed of a flexible tube, an operation wire inserted in the flexible sheath so as to be movable along an axial direction of the operation wire in the flexible sheath, and a front-end treatment member attached to a tip of the operation wire. In this structure, the front-end treatment member is movable back and forth along the axial direction with respect to a tip of the flexible sheath. The front-end treatment member has a wide part elongated in a radial direction of the flexible tube to press and broaden the flexible tube from an inside of the flexible tube.