Abstract: Endoscopic surgical operation method includes: a step of lifting a living tissue including an diseased tissue located distally relative to an operation channel of an endoscope inserted through a natural orifice; a step of suturing a proximal region and a distal region of the living tissue positioned basal relative to the diseased tissue lifted by a suturing means section projecting distally from the operation channel of the endoscope after the lifting; and a step of resecting the living tissue between the sutured regions and the diseased tissue endoscopically after suturing the proximal region and the distal region of the living tissue surrounding the diseased tissue.

Abstract: A medical treatment system including an endoscope, a treatment tool that is inserted in a channel of the endoscope, and a holder that holds the treatment tool in a manner that enables a user who operates the endoscope to move the treatment tool forward and backward and rotate the treatment tool, with the treatment tool having a treatment portion that performs treatment on a living body; a wire for operating the treatment portion whose distal end is connected to the treatment portion; a sheath portion that has a first sheath that is formed with a coil and in which the wire is inserted in a manner capable of moving forward and backward in the axial direction, and a second sheath that is formed with a coil of a plurality of layers and provided on the outside of the first sheath; and an operating portion to which the base end of the wire is connected and enables forward/backward and rotation operation of the wire; and with the holder holding the operating portion so as to be in a predetermined positional relation