Grasping treatment unit, grasping treatment instrument, and grasping treatment system

A grasping treatment unit configured to grasp and treat a living tissue, the grasping treatment unit comprising:

• a first jaw extending from a proximal portion toward a distal portion of the first jaw, the first jaw having an outer surface exposed to an outside;
• a second jaw extending from a proximal portion toward a distal portion of the second jaw, the second jaw being configured to be openable and closable relative to the first jaw;
• a treatment surface disposed on the outer surface of the first jaw and facing the second jaw, the treatment surface being configured to treat the living tissue;
• and
• a heating wire continuously disposed in a range from the proximal portion to the distal portion of the first jaw, the heating wire being configured to generate heat over an entire length of the heating wire when an electric current flows through the heating wire, the heating wire including:
• a first extending end and a second extending end, which is an opposite end of the heating wire from the first extending end, the first extending end and the second extending end being located in a proximal portion of the first jaw,
• a turn position located between the first extending end and the second extending end, the turn position being located in a distal portion of the first jaw, and
• at least three regions different from each other in path length of the heating wire per unit area, the at least three regions including:
• a first region located in a range from the turn position to a first boundary position, the first boundary position being located on a side of the proximal portion of the first jaw with respect to the turn position,
• a second region located in a range from the first boundary position to a second boundary position, the second boundary position being located on the side of the proximal portion of the first jaw with respect to the first boundary position, and the path length of the heating wire per unit area in the first region is shorter than the path length of the heating wire per unit area in the second region, and
• a third region located in a range from the second boundary position to the first extending end and the second extending end, and the path length of the heating wire per unit area in the second region is shorter than the path length of the heating wire per unit area in the third region,
• wherein in the heating wire, a sectional area perpendicular to an extending direction of the heating wire is larger in the distal portion than in the proximal portion in the first jaw.

A grasping system comprising:

• a first jaw including a treatment surface, the first jaw extending from a proximal portion toward a distal portion of the first jaw;
• a second jaw facing the treatment surface of the first jaw, the second jaw being configured to be openable and closable relative to the first jaw;
• a heating wire disposed on the treatment surface of the first jaw, both ends of the heating wire being located in the proximal portion of the first jaw, the heating wire including:
• a turn position located in the distal portion of the first jaw, the heating wire being turned at the turn position, and
• at least three regions different from each other in path length of a heating wire per unit area, the at least three regions including:
• a first region located in a range from the turn position to a first boundary position, the first boundary position being located on a side of the proximal portion of the first jaw with respect to the turn position,
• a second region located in a range from the first boundary position to a second boundary position, the second boundary position being located on the side of the proximal portion of the first jaw with respect to the first boundary position, and the path length of the heating wire per unit area in the first region is shorter than the path length of the heating wire per unit area in the second region, and
• a third region located in a range from the second boundary position to the first extending end and the second extending end, and the path length of the heating wire per unit area in the second region is shorter than the path length of the heating wire per unit area in the third region;
• and
• an energy source configured to output electric power to be supplied to the heating wire through both of the ends of the heating wire, the energy source being configured to pass an electric current through the heating wire by outputting the electric power.