Instrument insertion assisting tool

An instrument insertion assisting tool for use with an endoscope including a tube through which a treatment instrument and a guide wire used for guiding the treatment instrument being inserted into an insertion portion, a forceps port through which the tube is open outwardly on a manipulator, and a forceps plug mounted on the forceps port in closing relation thereto, the forceps plug including a hole and a slit through which the instrument and the guide wire extends, the instrument insertion assisting tool comprising:

• a plate-shaped wire attaching member configured to attach to the manipulator of the endoscope at a position adjacent to the forceps plug and offset from the hole;
• a plate-shaped guide piece projecting from the wire attaching member for partially controlling a direction along which the guide wire projecting from the forceps plug extends to cause a portion of the guide wire that is positioned immediately after projecting from the forceps plug to extend along a central axis of the hole, the guide piece including a protrusive end that includes an engaging cavity formed in a u-shape on an outermost edge of the protrusive end, the outermost edge of the protrusive end being configured to extend to a center axis of the slit of the forceps plug;
• a hook-shaped first engaging member projecting from the wire attaching member for engaging the guide wire which extends along the direction controlled by the guide piece;
• and
• second engaging member formed in a tortuous shape configured to engage another portion of the guide wire which is engaged by the first engaging member.