Closure device

1. A closure device comprising:

a first longitudinal member which extends along a longitudinal axis;

a second longitudinal member which extends along the longitudinal axis so as to be movable relative to the first longitudinal member;

a protruding member which is detachably provided at a distal end of the first longitudinal member;

a first grasping member which is provided at the protruding member and intersects with the protruding member, and which includes a first distal end portion and a first intermediate portion, the first distal end portion being configured to grasp tissue in cooperation with the protruding member, and the first intermediate portion being supported so as to be turnable with respect to the protruding member;

a second grasping member which is provided at the protruding member and intersects with the protruding member, and which includes a second distal end portion and a second intermediate portion, the second distal end portion being configured to grasp tissue in cooperation with the protruding member, and the second intermediate portion being supported so as to be turnable with respect to the protruding member;

a first operating portion which is provided at a proximal side of the first longitudinal member, and which is configured to operate the first grasping member;

a second operating portion which is provided at the proximal side of the first longitudinal member, and which is configured to operate the second grasping member independently from the first grasping member;

a turning shaft which supports the first grasping member and the second grasping member such that the first grasping member and the second grasping member are turnable relative to the protruding member, the turning shaft being provided in an orthogonal direction with respect to a longitudinal direction of the first intermediate portion and the second intermediate portion;

a first linear member which is connected to a proximal end of the first grasping member and to a distal end of the first operating portion, and which extends along the longitudinal axis;

a second linear member which is connected to a proximal end of the second grasping member and to a distal end of the second operating portion, and which extends along the longitudinal axis so as to be movable relative to the first linear member; and

a holding portion that has an action portion for applying a force in a direction in which the proximal end of the first grasping member and the proximal end of the second grasping member approach the protruding member with respect to the turning shaft, the holding portion being provided at a distal end of the second longitudinal member, and the holding portion being configured to be attached to or removed from the distal end of the second longitudinal member together with the first grasping member and the second grasping member.

2. The closure device according to claim 1 , wherein

the holding portion is formed in the shape of a tube,

the action portion is an inner peripheral surface of the holding portion,

the first grasping member and the second grasping member are closed by applying a force to portions of the first grasping member and the second grasping member that have come into contact with the inner peripheral surface toward a central axis of the holding portion, and

a concave-convex portion is formed on the inner peripheral surface of the holding portion on a cross-section including the central axis of the holding portion.

3. The closure device according to claim 2 , wherein the inner peripheral surface of the holding portion is formed so that a diameter thereof increases toward a distal end side.

4. The closure device according to claim 2 , wherein

the holding portion includes:

an external member which is formed in a shape of a tube and is configured to be attached to or removed from the distal end of the second longitudinal member; and

an internal member which is formed in a shape of a tube, has the concave-convex portion formed on an inner peripheral surface thereof, and is arranged inside the external member,

the inner peripheral surface of the external member is formed so that a diameter thereof increases toward a distal end side, and

an outer peripheral surface of the internal member is formed so that a diameter thereof increases toward the distal end side.

5. The closure device according to claim 4 , wherein the external member and the internal member are connected by a ratchet mechanism that allows a movement of the internal member to a proximal end side relative to the external member and regulates the movement of the internal member to the distal end side relative to the external member.

6. The closure device according to claim 4 , wherein

an inner diameter of a distal end side of the internal member is larger than an inner diameter of a proximal end side of the internal member,

the inner peripheral surface of the internal member has a step portion between the distal end side and the proximal end side of the internal member, and

the concave-convex portion is formed at the portion of the inner peripheral surface of the internal member closer to the distal end side than the step portion.

7. The closure device according to claim 1 , wherein

the first grasping member and the second grasping member are supported so as to be turnable around the turning shaft provided at the protruding member,

a length from the turning shaft to a distal end of each of the first grasping member and the second grasping member is set to be greater than a length from the turning shaft to a distal end of the protruding member, and

a distal end of one of the first grasping member and the second grasping member is provided with a protruding portion extending toward a distal end of the other of the first grasping member and the second grasping member.

8. The closure device according to claim 1 , wherein the holding portion is formed of an elastic material.

9. The closure device according to claim 1 , wherein a length from a distal end of the first grasping member to the turning shaft and a length from a distal end of the second grasping member to the turning shaft are each greater than a length from an axis which is provided at the proximal end of the first grasping member to the turning shaft and a length from an axis which is provided at the proximal end of the second grasping member to the turning shaft.