Patent Description:
A method of introducing a medical device into a hollow organ of the human body using a guide wire during a treatment or an examination of the hollow organ is known (for example, Patent Document <NUM>). In this method, the guide wire may not be able to be inserted into the hollow organ when an opening portion of the hollow organ has an obstacle such as a stenosis or occlusion. For example, when the duodenal papilla is occluded, it is difficult to insert a guide wire into a target hollow organ such as the bile duct or pancreatic duct via the duodenal papilla.

A method called a rendezvous method is known as a coping method in such a case. In the rendezvous method, a guide wire introduced into the bile duct or pancreatic duct from a region other than the duodenal papilla protrudes from the duodenal papilla, and an end portion of the protruding guide wire is held by a medical device. The guide wire protruding from the duodenal papilla is pulled out of the body via a treatment tool channel of an endoscope inserted into the duodenum. A stent or the like is placed using the guide wire pulled out of the body.

For example, Patent Document <NUM> discloses a medical device which can capture a guide wire protruding from the duodenal papilla. The medical device includes a tubular sheath, a wire inserted through the sheath, and a distal end portion provided at a distal end of the wire and extending in an extending direction of the wire. The distal end portion has a bent portion which is bent into a predetermined shape so that the guide wire is capable of being hooked.

Further, for example, as described in Patent Document <NUM>, a method is known in which, when a treatment tool such as a stent is placed by the rendezvous method, a guide wire protruding from the duodenal papilla into the duodenum is pulled back into the bile duct or pancreatic duct and thus a medical device gripping the guide wire is introduced into the bile duct or pancreatic duct together with the treatment tool.

In the rendezvous method, the bile duct or pancreas is observed on an ultrasound image, and a puncture needle punctures an intrahepatic bile duct or an extrahepatic bile duct from the esophagus, stomach, and duodenum. A guide wire is inserted inside the puncture needle that has punctured the bile duct, and a distal end of the guide wire is inserted inside the bile duct or the pancreatic duct. Then, the guide wire is pushed forward to pass through the duodenal papilla, and the distal end side portion of the guide wire is caused to protrude into the duodenum. Then, while the distal end side portion of the guide wire protruding from the papilla of the duodenum is observed on an endoscopic image, a part of the distal end side portion of the guide wire is gripped by a grip portion of a treatment tool (for example, a gripping forceps). The treatment tool is drawn into the papilla by pulling the guide wire in this state. Accordingly, for example, the treatment tool placed in the bile duct is capable of being placed in the bile duct in a state in which the treatment tool is covered with an indwelling object such as a stent, instead of a guide sheath.

Treatment tools for realizing a procedure disclosed in Patent Document <NUM> and Patent Document <NUM> have been studied (for example, Patent Document <NUM>). The device of Patent Document <NUM> captures the guide wire and inserts it into the duodenal papilla side along the guide wire to insert the treatment tool into the bile duct while minimizing damage to the papillary tissue. Specifically, the device of Patent Document <NUM> has a constitution in which a cutout portion is provided at a distal end portion of a sheath and a guide wire is held in the cutout portion. The endoscope catheter has a constitution in which the guide wire is inserted into the cutout portion by pressing an opening of the cutout portion from the side diagonally outward therefrom against the guide wire, and the sheath is slid along the guide wire in this state.

<CIT> describes a medical instrument capable of holding a guide wire through two contact surfaces of the sheath facing a direction along the central axis of the sheath. One of the contact surfaces is recessed in a direction parallel to the central axis of the sheath.

In the rendezvous method, a guide wire holder which is capable of being moved along the guide wire and is capable of being smoothly inserted into the papilla side is desired. In the endoscope catheter of Patent Document <NUM>, since the cutout portion provided at the distal end portion of the sheath is formed along a longitudinal axis of the sheath, it is necessary to align an axial direction of the sheath with an extending direction (an axial direction) of the guide wire to insert the guide wire into the cutout portion, but it is difficult to position the distal end portion of the sheath. Further, since the cutout portion is open on a side surface of the distal end portion of the sheath, the cutout portion may come off of the guide wire during an operation in which the sheath is inserted on the papilla side. When the cutout portion comes off of the guide wire, it is necessary to repeat the operation of inserting the guide wire into the cutout portion, and thus the procedure takes time.

The present invention has been made in view of the above circumstances, and an object thereof is to provide a guide wire holder which is able to be smoothly inserted along a guide wire toward the papilla side in a rendezvous method.

A guide wire holder according to one aspect of the present invention is set forth in claim <NUM>.

A method for inserting a guide wire holder into a papilla, this method not forming part of the claimed invention and further including a locking step of hooking the guide wire configured to protrude from the papilla on the hook, a guide wire-holding step of holding the guide wire hooked by the hook in a state in which the guide wire is along the inner wall surface by retracting the operation wire while the guide wire is hooked on the hook, and a sheath insertion step of inserting a distal end portion of the sheath into the papilla along the guide wire while pressing the inner wall surface against the guide wire in a state in which the guide wire is held between the guide wire engagement surface of the hook and the inner wall surface.

According to the present invention it is possible to provide a guide wire holder which is able to be smoothly inserted along a guide wire toward the papilla side, and a method for inserting the guide wire holder.

Hereinafter, a first example of a guide wire holder will be described with reference to <FIG>.

<FIG> is an overall view showing a guide wire holder <NUM> according to the example. <FIG> is a top view showing a distal end portion of the guide wire holder <NUM>. <FIG> is a top view showing the distal end portion of the guide wire holder <NUM> and is a view showing a state in which a hook shown in <FIG> is retracted. <FIG> is a front view of the guide wire holder <NUM> when seen from the distal side. <FIG> is a cross-sectional view along line V-V shown in <FIG>. <FIG> is a side view showing an aspect when the guide wire holder <NUM> is used. <FIG> is a view schematically showing a rotation-preventing portion <NUM> of the guide wire holder <NUM>.

The guide wire holder <NUM> according to the example is a medical device which is capable of holding a wire, for example, a medical guide wire that is inserted into the body when used. The guide wire holder <NUM> is a treatment tool constituted such that a hook <NUM> advances and retracts on the distal side of a sheath <NUM> as an operation wire <NUM> advances and retracts, and the guide wire located outside the sheath <NUM> is capable of being captured and held by the hook <NUM>. As shown in <FIG> and <FIG>, the guide wire holder <NUM> includes the sheath <NUM>, the operation wire <NUM>, the hook <NUM>, and an operation portion <NUM>.

The sheath <NUM> is a long flexible member. A proximal end portion of the sheath <NUM> is connected to an operation portion main body <NUM> of the operation portion <NUM> which is gripped by an operator. The sheath <NUM> is inserted into the body through an endoscope insertion portion and has such a length that a distal end portion of the sheath is capable of protruding from the endoscope. As shown in <FIG>, the sheath <NUM> has a first lumen <NUM> (a lumen) which extends in a direction of a longitudinal axis L. Further, the sheath <NUM> has a second lumen (a hook-accommodating lumen) <NUM> which extends parallel to the first lumen <NUM>. In a front view of the distal end of the sheath <NUM> seen in a direction along the longitudinal axis L of the sheath <NUM>, the first lumen <NUM> and the second lumen <NUM> are formed on both sides of a first diameter line R1 which is a straight line passing through a central axis O of the sheath <NUM> and orthogonal to the central axis O. The second lumen <NUM> has an inner diameter larger than an outer diameter of a second end portion <NUM>.

In <FIG>, although the longitudinal axis L and the central axis O are shown by the same line, the central axis O is an axis which passes through a center of the sheath <NUM> in a substantially circular cross-sectional shape, and the longitudinal axis L is an axis which extends in a longitudinal direction of the sheath <NUM>.

As shown in <FIG> and <FIG>, a groove <NUM> is formed in a part of an outer periphery of the sheath <NUM>. The groove <NUM> is formed in a concave shape at a part of an outer periphery of the sheath <NUM>. The groove <NUM> is formed to extend from the distal end of the sheath <NUM> toward the proximal side in the direction of the longitudinal axis L. As shown in <FIG>, the groove <NUM> is formed so that a part of the outer periphery of the sheath <NUM> is recessed from an outer peripheral surface toward the central axis O. The groove <NUM> has a depth D which is longer than a radius of the sheath <NUM>. In the groove <NUM>, at least at the distal end of the sheath <NUM>, as shown in <FIG>, in a front view, the groove <NUM> includes a bottom portion <NUM> located between the first lumen <NUM> and the second lumen <NUM>, and a distal end edge (a ridge line) <NUM> formed in a curved shape in which an opening width of the groove <NUM> widens from the bottom portion <NUM> toward the outer peripheral surface of the sheath <NUM>. The bottom portion <NUM> of the groove <NUM> is formed in an arc shape in a cross section orthogonal to the central axis O. An edge portion of the groove <NUM> on an outer peripheral opening portion <NUM> side (an opening side of the groove) on the outer peripheral side of the sheath <NUM> is formed in a curved shape and has a curved surface. The groove <NUM> opens on a first diameter line R1. The groove <NUM> does not necessarily have to have the depth D longer than the radius of the sheath <NUM> and may have a depth shorter than the radius of the sheath <NUM>.

The groove <NUM> is formed to extend from the distal end of the sheath <NUM> toward the proximal side in the direction of the longitudinal axis L. The groove <NUM> has the same shape as the distal end edge <NUM> from a distal end of the groove <NUM> to the proximal end of the groove. The groove <NUM> may be formed over the entire length of the sheath <NUM> or may be formed in a region of a predetermined length from the distal end toward the proximal side, for example, only in a portion which protrudes from a distal end of the endoscope insertion portion.

As shown in <FIG> and <FIG>, a pre-curved portion <NUM> is provided at the distal end portion of the sheath <NUM>. The pre-curved portion <NUM> has a curved shape which has a bending tendency in a predetermined direction. In the example, the pre-curved portion <NUM> has a curved shape which is curved to be bent in a direction of the first diameter line R1. The pre-curved portion <NUM> is elastically deformed when an external force is applied, but in a natural state in which the external force is released, the pre-curved portion <NUM> has a restoring force which restores the curved shape given in advance. The groove <NUM> is formed at a position at which it opens outside the curved shape of the pre-curved portion <NUM> when the pre-curved portion <NUM> is restored to the curved shape.

The operation wire <NUM> is formed of a single wire or a stranded wire made of a metal and is inserted through the first lumen <NUM> of the sheath <NUM>. A proximal end of the operation wire <NUM> is fixed to an operation slider <NUM> of the operation portion <NUM>, and the hook <NUM> is connected to a distal end of the operation wire <NUM>.

A rotation-preventing portion <NUM> is provided in the operation wire <NUM> and the first lumen <NUM>. The rotation-preventing portion <NUM> prevents the operation wire <NUM> from rotating about the axis with respect to the first lumen <NUM>. The rotation-preventing portion <NUM> includes a non-perfect circle portion <NUM> (a restricted portion) provided in the operation wire <NUM> and a non-perfect circle opening portion <NUM> (a restricting portion) provided in the first lumen <NUM>. The non-perfect circle portion <NUM> is a portion of which a cross-sectional shape orthogonal to an axial direction of the operation wire <NUM> is elliptical (non-perfect circle). The non-perfect circle opening portion <NUM> is an elliptical opening which has an elliptical ( non-perfect circle) opening shape and is provided to have a predetermined length from the distal end of the first lumen <NUM> toward the proximal side and of which a cross-sectional shape thereof orthogonal to the direction of the longitudinal axis L of the sheath <NUM> is similar to that of the non-perfect circle portion <NUM> of the operation wire <NUM>. As shown in <FIG>, the non-perfect circle opening portion <NUM> has an opening size which allows the operation wire <NUM> to advance and retract and in which the non-perfect circle portion <NUM> cannot rotate about the axis of the operation wire <NUM>. The restricting portion and the restricted portion may have a non-perfect circle shape and may have an elliptical shape or an oval shape.

As shown in <FIG>, a dimension L1 of the non-perfect circle opening portion <NUM> in a short side direction of the elliptical shape is larger than a dimension L2 of a cross section of the non-perfect circle portion <NUM> in a short side direction thereof. A dimension L3 of the non-perfect circle opening portion <NUM> in a long side direction of the elliptical shape is larger than the dimension L1 of the non-perfect circle portion <NUM> in the short side direction and a dimension L4 thereof in the long side direction. Therefore, when the operation wire <NUM> rotates about its own axis, the non-perfect circle portion <NUM> comes into contact with an inner wall of the non-perfect circle opening portion <NUM>, and rotation of the operation wire <NUM> about the axis is restricted. As a result, the operation wire <NUM> is constituted to be able to advance and retract in the first lumen <NUM> while the operation wire <NUM> is prevented from rotating about the axis with respect to the sheath <NUM>.

The non-perfect circle portion <NUM> of the operation wire <NUM> is provided in a region at which the operation wire <NUM> passes through the non-perfect circle opening portion <NUM> of the distal end portion of the first lumen <NUM> when the operation wire <NUM> advances and retracts with respect to the sheath <NUM>. In the example, in the operation wire <NUM>, the elliptical non-perfect circle portion <NUM> is provided in a part of the operation wire <NUM> in the longitudinal direction, and a cross-sectional shape of a portion other than the non-perfect circle portion <NUM> is substantially completely circular.

As shown in <FIG>, the hook <NUM> is provided to be continuous with the distal end of the operation wire <NUM>. The hook <NUM> is formed by bending a wire-shaped member toward the distal end side of the guide wire holder <NUM> in a convex shape. The hook <NUM> includes a first end portion <NUM> which has end portions on both sides of a convex bending region <NUM> and is connected to the distal end of the operation wire <NUM>, and a second end portion <NUM> which extends toward the proximal end side of the sheath <NUM> along the longitudinal axis. The hook <NUM> may be formed of a single wire made of a metal such as SUS or a nickel titanium alloy.

The hook <NUM> is provided to protrude from the distal end of the sheath <NUM>. The hook <NUM> advances and retracts at the distal side of the sheath <NUM> as the operation wire <NUM> advances and retracts with respect to the sheath <NUM>.

As shown in <FIG>, in a front view, the hook <NUM> is formed to be bent in a radial direction (a direction of the first diameter line R1) of the sheath <NUM> and to the side on which the groove <NUM> is located. In a side view in a direction orthogonal to the direction of the longitudinal axis L of the sheath <NUM> and a direction orthogonal to a bending direction of the pre-curved portion <NUM>, the hook <NUM> is formed so that the distal end side of the hook <NUM> is bent toward the groove <NUM> side at a right angle or an obtuse angle with the distal end part of the guide wire. As shown in <FIG>, in a front view, a protruding end portion <NUM> of the curved portion at the distal end of the hook <NUM> is located outward from the bottom portion <NUM> of the groove <NUM> in the radial direction of the sheath <NUM>. That is, the hook <NUM> is bent toward the groove <NUM> in the direction of the first diameter line R1 between the first end portion <NUM> and the second end portion <NUM> and the protruding end portion <NUM>. An inner surface of the curved portion of the protruding end portion <NUM> serves as a guide wire engagement surface <NUM> which is capable of engaging with the guide wire. Here, the engagement means that the hook hooks the guide wire, and is used regardless of whether the guide wire can advance and retract with respect to the hook.

In a front view, the hook <NUM> intersects the distal end edge <NUM> of the groove <NUM>, and a closed region C1 closed by the hook <NUM> and the distal end edge <NUM> is formed. As shown in <FIG>, in a first side view (a top view) along the first diameter line R1, when the hook <NUM> is disposed at a retracted position, the second end portion <NUM> is accommodated in the distal end of the sheath <NUM> to form a closed region C2 between the hook <NUM> and the distal end of the sheath <NUM>.

As shown in <FIG>, the operation portion <NUM> is provided on the proximal end side of the guide wire holder <NUM> and is connected to the proximal end of the sheath <NUM>. The operation portion <NUM> includes an operation portion main body <NUM> and the operation slider <NUM>. The operation portion main body <NUM> is connected to the proximal end of the sheath <NUM>. The operation slider <NUM> is slidably mounted on the operation portion main body <NUM>. The operation portion main body <NUM> has a hollow portion, and a slit (not shown) which is allowed to communicate with the hollow portion and the outside and extends along the longitudinal axis L is formed. A part of the operation slider <NUM> is inserted through the slit, and the operation slider <NUM> is connected to the proximal end portion of the operation wire <NUM> in the hollow portion. When the operation slider <NUM> is advanced and retracted with respect to the operation portion main body <NUM> in the direction of the longitudinal axis L of the sheath <NUM>, the operation wire <NUM> advances and retracts with respect to the sheath <NUM>, and the hook <NUM> is capable of advancing and retracting on the distal end side of the sheath <NUM> according to the advancing and retracting of the operation wire <NUM>.

When the operation slider <NUM> is advanced with respect to the operation portion main body <NUM>, the operation wire <NUM> advances in the first lumen <NUM>, and the hook <NUM> advances on the distal side of the sheath <NUM>. When the operation slider <NUM> is advanced furthest to the distal side in a movable range of the operation slider <NUM>, the hook <NUM> is disposed at the most advanced position with respect to the sheath <NUM>. As shown in <FIG>, the second end portion <NUM> of the hook <NUM> is separated from the distal end of the sheath <NUM> in the advanced position. Specifically, a separation distance LS (refer to <FIG>) between the second end portion <NUM> and the distal end of the sheath <NUM> in the advanced position is longer than a diameter of a guide wire GW which will be described later.

The second end portion <NUM> is capable of being accommodated in the second lumen <NUM> by retracting the operation wire <NUM>. When the operation slider <NUM> is retracted furthest to the proximal side in the movable range of the operation slider <NUM>, as shown in <FIG>, the hook <NUM> is disposed at the most retracted position with respect to the sheath <NUM>, and the second end portion <NUM> enters a distal end opening of the second lumen <NUM> and is accommodated therein.

Since the rotation of the operation wire <NUM> around the axis is prevented by the rotation-preventing portion <NUM>, the hook <NUM> advances and retracts while a relative position around the axis with respect to the central axis O of the sheath <NUM> is maintained. Therefore, the second end portion <NUM> is capable of reliably entering the distal end opening of the second lumen <NUM> at the retracted position of the hook <NUM>.

Next, a usage aspect of the guide wire holder <NUM> and a method for inserting the guide wire holder will be described, these methods not forming part of the invention as claimed here. In the following, a method for introducing the guide wire holder <NUM> into a hollow organ, for example, the bile duct, by the rendezvous method will be described as an example. <FIG> is a flowchart showing the method for inserting the guide wire holder according to the example. <FIG> are schematic views showing an aspect when the guide wire holder <NUM> is used. <FIG> is a schematic view showing an example in which a procedure is performed by the rendezvous method using the guide wire holder <NUM>.

First, a first guide wire GW (the guide wire) is placed in a duodenum D. Specifically, as shown in <FIG>, an endoscope insertion portion <NUM> of an ultrasonic endoscope <NUM> is inserted from the mouth of a patient into the stomach St or the duodenum D, and an access needle <NUM> which is inserted through the endoscope insertion portion <NUM> and protrudes from the distal end of the endoscope insertion portion <NUM> punctures the bile duct Bd. Then, the first guide wire GW is inserted into the endoscope insertion portion <NUM>, and the first guide wire GW is inserted into the bile duct Bd via the access needle <NUM>. The first guide wire GW inserted into the bile duct Bd is pushed forward, and the distal end of the first guide wire GW protrudes from the duodenal papilla Dp into the duodenum D. Normally, the distal end of the first guide wire GW which protrudes from the duodenal papilla Dp is made to extend along the lumen of the duodenum D by advancing the first guide wire GW toward the duodenal papilla Dp. After that, the ultrasonic endoscope <NUM> is removed with the first guide wire GW left inside the body, and the distal end of the first guide wire GW is placed in the duodenum D. At this time, a proximal end part of the first guide wire GW is outside the patient's body.

Next, the endoscope insertion portion <NUM> (refer to <FIG>) of a duodenoscope (not shown) is inserted from the patient's mouth to the duodenum D. Then, the guide wire holder <NUM> is inserted into the endoscope insertion portion <NUM>, and the distal end portion of the sheath <NUM> protrudes from the distal end of the endoscope insertion portion <NUM>. At this time, the distal end portion of the sheath <NUM> is raised by an elevator (not shown) provided at a distal end portion of a treatment tool channel <NUM> of the endoscope insertion portion <NUM>. When the distal end portion of the sheath <NUM> protrudes from the treatment tool channel <NUM> of the endoscope insertion portion <NUM>, the pre-curved portion <NUM> is restored to a predetermined curved shape. Therefore, the distal end portion of the sheath <NUM> is capable of being easily arranged to be displayed in an endoscopic image, and the sheath <NUM> is also capable of being guided in a direction in which the hook <NUM> easily hooks the guide wire GW. The guide wire GW is capable of being easily inserted into the groove <NUM>. Since the second end portion <NUM> of the hook <NUM> is located in the central part of the endoscopic image, the second end portion <NUM> is capable of being seen closer to a center of the endoscopic image than the first guide wire GW. As a result, in the endoscopic image, a gap between the second end portion <NUM> and the sheath <NUM> is prevented from being blocked by the first guide wire GW, and the hook <NUM> is capable of smoothly hooking the first guide wire GW.

As shown in <FIG>, an operator operates the operation portion <NUM> while checking the endoscopic image obtained by the duodenoscope. Specifically, the endoscope insertion portion <NUM> is disposed so that the first guide wire GW which protrudes from the duodenal papilla Dp toward the inside of the duodenum D is displayed in the endoscopic image, and in this state, the sheath <NUM> protrudes from the endoscope insertion portion <NUM> to bring the sheath <NUM> close to the first guide wire GW. As shown in <FIG>, the distal end portion of the sheath <NUM> is imaged to protrude from the lower right side of the endoscopic image and is reflected therein. When the sheath <NUM> is caused to protrude from the endoscope, the sheath <NUM> is disposed at a position at which the gap between the second end portion <NUM> of the hook <NUM> and the distal end of the sheath <NUM> is capable of being visible in the endoscopic image. That is, the second end portion <NUM> is displayed closer to the proximal side than the first end portion <NUM> in the endoscopic image.

Then, the operation slider <NUM> is advanced toward the distal side, the operation wire <NUM> is advanced with respect to the sheath <NUM>, and the hook <NUM> is advanced to the advanced position with respect to the sheath <NUM> (a hook advance step S1).

As shown in <FIG>, the operator inserts the first guide wire GW into the gap between the second end portion <NUM> of the hook <NUM> and the distal end of the sheath <NUM> while checking the endoscopic image. Then, the first guide wire GW is hooked by the hook <NUM> (a locking step S2).

The guide wire GW which protrudes from the duodenal papilla Dp runs from the upper side to the lower side in the endoscopic image, and the vicinity of the distal end of the endoscope is displayed on the lower side of the endoscopic image. On the other hand, when the pre-curved portion <NUM> passes through a forceps-elevator <NUM>, the outside of the curve of the pre-curved portion <NUM> faces the forceps-elevator <NUM> (refer to <FIG>). Therefore, since the groove <NUM> is formed on the outside of the curve of the pre-curved portion <NUM>, the groove <NUM> is located below the endoscopic image when the pre-curved portion <NUM> protrudes from the endoscope. As a result, it becomes easy to accommodate the guide wire GW in the groove <NUM> of the sheath <NUM>. Since a vector of a force pushing the sheath <NUM> is easily converted in a long axis direction of the guide wire GW, the distal end portion of the sheath <NUM> is likely to follow the guide wire GW.

Next, the operator retracts the operation slider <NUM> toward the proximal side, retracts the operation wire <NUM> with respect to the sheath <NUM> and places the hook <NUM> in the retracted position. The first guide wire GW is capable of being brought close to the distal end edge of the groove <NUM> by retracting the hook <NUM> to the retracted position. In the retracted position, the second end portion <NUM> of the hook <NUM> is inserted into the second lumen <NUM>, and the first guide wire GW is disposed and captured in the closed regions C1 and C2 between the hook <NUM> and the sheath <NUM> (a guide wire-holding step S3).

In the state in which the hook <NUM> is retracted to the retracted position, the guide wire GW is guided by the guide wire engagement surface <NUM> and inserted into the groove <NUM>. In the retracted position, the guide wire engagement surface <NUM> of the hook <NUM> is located closer to the distal side than a distal end of the outer peripheral opening portion <NUM> (the opening portion) of the groove <NUM>. At this time, the guide wire GW is captured and held by an inner wall surface <NUM> of the groove <NUM> and the guide wire engagement surface <NUM> of the hook <NUM> in a state in which the guide wire GW is arranged from the groove <NUM> toward the proximal end side of the sheath <NUM> along the direction of the longitudinal axis L. The guide wire GW is preferably held between the guide wire engagement surface <NUM> of the hook <NUM> and the inner wall surface <NUM> of the groove <NUM> to be able to advance and retract. The guide wire GW is capable of being prevented from coming off from the guide wire holder <NUM> by holding the guide wire GW between the guide wire engagement surface <NUM> of the hook <NUM> and the inner wall surface <NUM> of the groove <NUM>.

Next, in a state in which the guide wire GW is held between the hook <NUM> and the groove <NUM>, the distal end portion of the sheath <NUM> is inserted into the duodenal papilla Dp along the guide wire GW while the inner wall surface <NUM> of the groove <NUM> is pressed against the guide wire GW (a sheath insertion step S4). The operator pushes the operation portion <NUM> and inserts the distal end portion of the sheath <NUM> into the duodenal papilla Dp as shown in <FIG>. Since the first guide wire GW passes through the bile duct Bd and extends to the duodenum D via the duodenal papilla Dp in advance, when the guide wire holder <NUM> is pushed in, the sheath <NUM> advances along the first guide wire GW and reaches the inside of the bile duct Bd.

Since the closed regions C1 and C2 are sufficiently larger than the diameter of the first guide wire GW, the sheath <NUM> and the hook <NUM> do not generate a large frictional resistance with the first guide wire GW. Therefore, the sheath <NUM> is capable of being smoothly advanced and retracted along the first guide wire GW. Further, when the sheath <NUM> is advanced into the duodenal papilla Dp, the first guide wire GW is disposed in the groove <NUM> of the sheath <NUM> in the direction of the longitudinal axis L of the sheath <NUM>, and the guide wire GW is also held between the hook <NUM> and the groove <NUM>. As a result, a state in which the first guide wire GW is disposed along the longitudinal axis L of the sheath <NUM> is maintained. At this time, at least a part of the hook <NUM> is located distant from the distal end of the groove <NUM>. Further, the first guide wire GW is held along the longitudinal axis L at a position closer to the central axis O of the sheath <NUM>, and as described above, the sheath <NUM> and the hook <NUM> smoothly advance and retract with respect to the first guide wire GW. Therefore, the sheath <NUM> and the hook <NUM> is capable of being easily inserted into the bile duct Bd. In this way, the insertion of the first guide wire GW into the bile duct Bd is completed.

After the insertion of the first guide wire GW into the bile duct Bd is completed, an intended treatment is performed. As a specific example, a second guide wire different from the first guide wire GW is inserted into another lumen (not shown) of the sheath <NUM> or the second lumen <NUM>, and the second guide wire is inserted into the duodenal papilla Dp. Then, the first guide wire GW and the guide wire holder <NUM> are removed from the endoscope insertion portion <NUM>.

After that, another endoscopic treatment tool is inserted into the duodenoscope and is inserted into the duodenum along the second guide wire, and then a treatment in the duodenum is performed. Examples of treatments performed by another endoscopic treatment tool include injection of a contrast medium, calculus removal, and a placement of a stent, and the like.

According to the guide wire holder <NUM> of the example, since the hook <NUM> which protrudes from the distal end of the sheath <NUM> and is capable of advancing and retracting with respect to the sheath <NUM> is provided, the guide wire GW is capable of being held by the hook <NUM>. According to the guide wire holder <NUM> of the example, the guide wire GW is capable of being easily hooked by the hook <NUM> by disposing the hook <NUM> at the advanced position. When the guide wire GW is hooked by the hook <NUM>, the gap formed between the second end portion <NUM> and the distal end of the sheath <NUM> is capable of being visually recognized in the endoscopic image, and thus the guide wire GW is easily hooked by the hook <NUM>. Since the separation distance LS between the second end portion <NUM> and the distal end of the sheath <NUM> at the advanced position of the hook <NUM> is larger than the outer diameter of the guide wire GW, the guide wire GW is capable of being easily hooked by the hook <NUM>. Then, the guide wire GW is capable of being prevented from coming off from the hook <NUM> by disposing the hook <NUM> at the retracted position.

Since the closed regions C1 and C2 formed by the guide wire engagement surface <NUM> of the hook <NUM> and the distal end edge (the ridge line) <NUM> of the distal end of the groove <NUM> of the sheath <NUM> are larger than the outer diameter of the guide wire GW, the guide wire GW captured in the closed regions C1 and C2 are capable of smoothly advancing and retracting in the closed regions C1 and C2. As a result, when the distal end portion of the guide wire holder <NUM> is inserted into the duodenum, the sheath <NUM> is capable of being easily advanced along the guide wire GW.

According to the guide wire holder <NUM> of the example, the rotation of the operation wire <NUM> around its own axis is restricted by the rotation-preventing portion <NUM>. As a result, when the hook <NUM> advances and retracts, the second end portion <NUM> of the hook <NUM> is prevented from rotating around the central axis O of the sheath <NUM>, and the second end portion <NUM> is capable of being reliably inserted into the second lumen <NUM> when the hook <NUM> retracts.

Since the guide wire holder <NUM> according to the example includes the groove <NUM> formed along the longitudinal axis L on the outer periphery of the sheath <NUM>, when the inner wall surface <NUM> of the groove <NUM> is pressed against the guide wire GW located outside the sheath <NUM>, the guide wire GW is capable of being easily inserted into the groove <NUM>.

According to the guide wire holder <NUM> of the example, in a front view seen in the direction along the longitudinal axis L, the hook <NUM> intersects the distal end edge <NUM> of the groove <NUM>, and the closed region C1 closed by the hook <NUM> and the distal end edge <NUM> is formed. Therefore, in a state in which the hook <NUM> is disposed at the retracted position, the guide wire GW located outside the sheath <NUM> is capable of being captured in the groove <NUM> and held in the closed region C1. As a result, the guide wire GW is capable of being easily hooked by the hook <NUM> by the advancing and retracting operation of the operation wire <NUM>, and the guide wire GW is capable of being surrounded and held between the guide wire engagement surface <NUM> of the hook <NUM> and the distal end edge <NUM> of the groove <NUM>. Therefore, when the sheath <NUM> is inserted into the duodenal papilla Dp, the hook <NUM> does not come off from the guide wire GW, and the sheath <NUM> is capable of being inserted into the duodenal papilla Dp in a stable state.

According to the guide wire holder <NUM> of the example, since the guide wire GW is inserted and held in the groove <NUM>, the guide wire GW is capable of being held near the central axis O of the sheath <NUM>. Therefore, the guide wire GW is capable of being held by a simple operation, and the sheath <NUM> is capable of being smoothly advanced along the guide wire GW in the hollow organ. Furthermore, since the guide wire GW is captured and held along the groove <NUM>, when the sheath <NUM> is inserted into the duodenal papilla Dp, a diameter of a portion including the sheath <NUM> and the guide wire GW is capable of being curbed, and the sheath <NUM> is capable of being easily inserted into the duodenal papilla Dp.

Since the guide wire holder <NUM> according to the example includes the pre-curved portion <NUM> in the sheath <NUM>, and the groove <NUM> is formed to open outside a restored curved shape of the pre-curved portion <NUM>, the guide wire GW is capable of being easily inserted into the groove <NUM>. Also, the pre-curved portion <NUM> is not an essential component, and the guide wire holder <NUM> is capable of smoothly inserting the guide wire GW into the groove <NUM> even when the sheath <NUM> does not include the pre-curved portion <NUM>.

The guide wire holder according to the present invention is not limited to the example of the above-described example. For example, modified examples shown in <FIG> can be cited. In the following description, the same components as those already described will be designated by the same reference numerals, and duplicate description thereof will be omitted.

<FIG> is a front view of a guide wire holder 1A according to a first modified example. As shown in <FIG>, a resin cover member <NUM> may be provided on the hook <NUM>. The frictional resistance between the guide wire GW and the hook <NUM> is capable of being reduced by providing the resin cover member <NUM> on a portion of the hook <NUM> which protrudes from the sheath <NUM>. As a result, when the sheath <NUM> is pushed along the guide wire GW, the sheath <NUM> is capable of being pushed in easily. The cover member <NUM> is not an essential component. For example, in addition to the resin cover, the hook may be coated with a lubricant or PTFE coating. In addition, when the closed regions C1 and C2 are sufficiently wide with respect to the diameter of the guide wire GW, contact between the guide wire GW and the hook <NUM> is curbed, and thus the cover member <NUM> is unnecessary.

<FIG> is a top view of a guide wire holder 1B of a second modified example. The second modified example shown in <FIG> is different from the first example in the constitution of the hook-accommodating lumen of the second end portion <NUM> of the sheath <NUM>. In the second modified example, a bottomed concave portion 22B which opens to a distal end surface 27B of the sheath <NUM> is formed in the sheath <NUM>. The concave portion 22B serves as the hook-accommodating lumen of the second end portion <NUM> when the hook <NUM> is located at the retracted position. In the first example, an example in which the second lumen <NUM> in which a duct is formed over the entire length of the sheath <NUM> and through which a contrast medium or another wire is capable of being inserted is used as the hook-accommodating lumen is provided. However, for the purpose of accommodating the second end portion <NUM> of the hook <NUM>, instead of the second lumen <NUM> formed over the entire length, a concave portion may be formed only at the distal end of the sheath <NUM> and the second end portion <NUM> may be accommodated in the concave portion. Since the hook-accommodating lumen is provided separately from the second lumen <NUM>, the second lumen <NUM> is capable of being used for other purposes in a state in which the hook <NUM> is held at the retracted position. For example, the second guide wire is capable of being supplied from the second lumen <NUM> in the state in which the hook <NUM> is held at the retracted position.

<FIG> is a top view of a guide wire holder 1C of a third modified example. <FIG> is a front view of the guide wire holder 1C of the third modified example. The third modified example shown in <FIG> is different from the concave portion 22B of the second modified example in a shape. A concave portion 22C of the third modified example is formed to be recessed in a region including a boundary portion between the distal end surface 27C of the sheath <NUM> and the outer peripheral surface thereof. Even when the hook-accommodating lumen which is capable of accommodating the second end portion <NUM> has such a constitution, the second end portion <NUM> is capable of being easily accommodated.

<FIG> is a front view of a guide wire holder 1D of a fourth modified example. This modified example is an example without the hook-accommodating lumen. As shown in <FIG>, when the hook <NUM> is disposed at the retracted position, the second end portion <NUM> may be located outward from the outer peripheral surface of the distal end of the sheath <NUM> to be disposed close thereto. Also in such a modified example, when the hook <NUM> is retracted to the retracted position, the second end portion <NUM> is capable of being located closer to the proximal side than the distal end of the sheath <NUM>, and the closed region C1 is capable of being formed in a front view. When the hook-accommodating lumen is not provided and the hook <NUM> is disposed at the retracted position, the second end portion <NUM> may be in contact with or disposed close to the distal end of the sheath <NUM>. When the second end portion <NUM> is disposed close to the distal end of the sheath <NUM> at the retracted position of the hook <NUM>, and the separation distance LS between the second end portion <NUM> of the hook <NUM> and the distal end of the sheath <NUM> is smaller than the outer diameter of the guide wire, the guide wire GW is capable of being held.

<FIG> is a front view of a guide wire holder 1E according to a fifth modified example. In this modified example, as shown in <FIG>, an outer surface 22E which is substantially parallel to the longitudinal axis of the sheath <NUM> may be formed by D-cutting (cutting into a D-shape) a position of a distal end portion of a sheath 2E in which the second end portion <NUM> advances and retracts without forming the hook-accommodating lumen. Also in such a modified example, when the hook <NUM> is retracted to the retracted position, the second end portion <NUM> is capable of being located closer to the proximal side than the distal end of the sheath <NUM>, and the closed region C1 is capable of being formed in a front view.

<FIG> is a front view of a guide wire holder 1F of a sixth modified example. <FIG> is a cross-sectional view along line XVII-XVII in <FIG>. The sixth modified example shown in <FIG> is different from the sheath <NUM> of the first example in the shape and constitution of a distal end portion of a sheath 2F.

As shown in <FIG>, in this modified example, a cutout portion (a step) <NUM> is provided in a part of the distal end portion of the sheath 2F, and a dimension of the distal end portion of the sheath 2F is smaller than that of the proximal end side. The sheath 2F is capable of being more easily inserted into the duodenal papilla Dp by thus reducing a size of the distal end portion of the sheath 2F.

As shown in <FIG>, in the sheath 2F of the modified example, the groove <NUM> and a contrast lumen <NUM> are arranged and provided in the direction of the first diameter line R1, and the cutout portion <NUM> is provided at a distal end portion of the contrast lumen <NUM>. Therefore, a dimension of the cutout portion <NUM> in the direction of the longitudinal axis L is set to be equal to or less than a length in which the sheath 2F is inserted into the bile duct. This is because when the cutout portion <NUM> is longer than the length in which the sheath 2DF is inserted into the bile duct, a distal end opening of the contrast lumen is not inserted into the bile duct and the contrast medium cannot be injected into the bile duct. Further, preferably, the cutout portion <NUM> in the direction of the first diameter line R1 is formed to be cut out such that the first lumen <NUM> and the second lumen <NUM> do not communicate with the outside of the sheath 2F.

Further, in the above-described first example, although the distal end surface <NUM> of the sheath <NUM> is formed by a surface of the sheath <NUM> orthogonal to the longitudinal axis L, a distal end surface 27F of the sheath 2F may be formed to be inclined with respect to the central axis O, as shown in <FIG>. Specifically, in the distal end surface 27F of the sheath 2F may be formed to be inclined such that a portion <NUM> on the groove <NUM> side may be located on the distal end side and a portion <NUM> on the cutout portion <NUM> side may be located on the proximal side, and an inclination angle of the distal end surface 27F of the sheath 2F may be substantially parallel to an inclination angle of the hook <NUM> in a radial direction. In this way, in the case in which the part of the groove <NUM> side of the sheath 2F is located on the distal end side of the sheath, and the distal end surface 27F of the sheath 2F is inclined to be substantially parallel to the hook <NUM>, the distal end of the sheath 2F is capable of being smoothly inserted along the guide wire GW held at the hook <NUM> and the distal end of the sheath 2F when a sheath 2D is inserted into the duodenal papilla Dp.

The mode in which the dimension of the distal end portion of the sheath 2F is made smaller than that of the proximal end side is not limited to the form shown in this modified example. For example, the distal end portion of the sheath may be tapered so that the distal end side becomes thinner over the entire circumference.

<FIG> is a front view of a guide wire holder <NUM> of a seventh modified example. The seventh modified example is different from the first example in the constitution of the hook <NUM> and a sheath <NUM>. In this modified example, a first lumen 21E and a second lumen <NUM> are formed closer to the outer peripheral opening portion <NUM> of the groove <NUM> than the bottom portion <NUM> of the groove <NUM>. Further, the hook <NUM> is not curved in the radial direction and extends in the direction of the longitudinal axis L of the sheath <NUM> (a bending angle θ=<NUM> degrees). Also with such a constitution, the closed region C1 is capable of being formed between the distal end edge <NUM> of the groove <NUM> and a guide wire engagement surface <NUM> of the hook <NUM>. Therefore, similarly to the above-described first example, the guide wire GW is capable of being held in the closed region C1 while being accommodated in the groove <NUM>, and the sheath <NUM> is capable of being easily advanced and retracted along the guide wire GW. The bending angle of the hook (refer to <FIG>) is preferably a right angle or an obtuse angle (<NUM> degrees or more and less than <NUM> degrees), and as the bending angle θ in this range becomes smaller, a large area of the closed region C1 is capable of being secured in a front view of the distal end of the sheath <NUM>.

<FIG> is a front view of a guide wire holder 1I of an eighth modified example. <FIG> is a side view of <FIG>. In this modified example, in a front view, inclined surfaces (backcut surfaces) 26I may be provided on both sides of the groove <NUM> at a distal end portion of a sheath 2I. The inclined surface 26I is inclined from the distal end of the sheath 2I toward the proximal end side. In this case, when the hook <NUM> is pulled while the guide wire GW is hooked by the hook <NUM>, the guide wire GW easily enters the groove <NUM>.

<FIG> and <FIG> are side views of a guide wire holder 1J according to a ninth modified example. The modified example is an example in which a constitution of the restricted portion is different from that of the above-described example. The hook <NUM> extends to the distal end of the operation wire <NUM>, and the hook <NUM> and the operation wire <NUM> are joined by a joint <NUM>. A restricted portion 71J forms a bent portion <NUM> by bending an intermediate portion of a proximal end region of the hook <NUM>. The restricted portion 71J has a first portion <NUM> which extends further to the distal side than the restricted portion 71J and a second portion <NUM> which extends toward the proximal side. That is, a bent portion between the joint <NUM> and the hook <NUM> constitutes the restricted portion <NUM>. In this modified example, the restricted portion 71J is capable of being easily formed only by bending the hook <NUM>.

The first portion <NUM> is located further outward with respect to the curve of the pre-curved portion <NUM> than the second portion <NUM>, and the second portion <NUM> is located further inward with respect to the curve of the pre-curved portion. Further, the first portion <NUM> and the second portion <NUM> minimize a clearance to the inner wall of the first lumen <NUM>. Therefore, as shown in <FIG>, when a sheath 2J is raised by the forceps-elevator <NUM> provided in the endoscope insertion portion <NUM>, even if a force from the forceps-elevator <NUM> is applied to the sheath 2J from the outside of the curve of the pre-curved portion <NUM>, the first portion <NUM> which passes through the inside of the first lumen <NUM> is unlikely to be displaced inside the curve of the pre-curved portion <NUM>. As a result, a relative position between the second end portion <NUM> of the hook <NUM> and the sheath 2J is capable of being prevented from being displaced. Therefore, even when the pre-curved portion <NUM> is curved by the forceps-elevator <NUM>, a positional relationship between the second lumen <NUM> and the second end portion <NUM> is capable of being maintained.

The shape of the bent portion <NUM> of the restricted portion 71J is not limited to the shapes shown in <FIG> and <FIG>. For example, the modified example shown in <FIG> may be used. The modified example shown in <FIG> is an example in which, in a side view when the hook <NUM> is seen in a direction orthogonal to the longitudinal axis direction of the hook <NUM>, a bent portion <NUM> is bent into a V shape, and the first portion <NUM> and the second portion <NUM> are located substantially coaxially. The bent portion <NUM> is disposed on the groove <NUM> side or the side surface side in the first lumen. In the case of this modified example, the first portion <NUM> and the second portion <NUM>, and a vertex portion of the bent portion <NUM> are in contact with the first lumen <NUM> to restrict the rotation of the hook <NUM> with respect to the sheath 2J.

In the modified example shown in <FIG>, in a side view when the hook <NUM> is seen in the direction orthogonal to the longitudinal axis direction of the hook <NUM>, a bent portion <NUM> is bent into a Z shape, and the first portion <NUM> and the second portion <NUM> have their axes offset in the radial direction. In this modified example, when the sheath 2J is raised by the forceps-elevator <NUM> as in the restricted portion 71J shown in <FIG>, even if a force from the forceps-elevator <NUM> is applied to the sheath 2J from the outside of the curve of the pre-curved portion <NUM>, the first portion <NUM> which passes through the inside of the first lumen <NUM> is unlikely to be displaced inside the curve of the pre-curved portion <NUM>.

<FIG> is a view schematically showing a cross section of a guide wire holder <NUM> of a tenth modified example in the longitudinal axis direction. In this modified example, as in the sheath 2F of the sixth modified example, a distal end surface <NUM> of a sheath <NUM> is formed to be inclined with respect to the central axis O. A portion <NUM> of the distal end surface <NUM> of the sheath <NUM> on the groove <NUM> side is inclined to be located on the distal end side of the sheath. Further, the shape of a second end portion <NUM> of the hook <NUM> is different from that in the above-described first example. Specifically, a bent portion <NUM> is formed at a proximal end of the second end portion <NUM> in direction of the longitudinal axis. The bent portion <NUM> is folded back in a direction which intersects the longitudinal axis of the second lumen <NUM>, and an end portion <NUM> extends at the same angle as the inclination angle of the distal end surface <NUM>. The end portion <NUM> of the second end portion <NUM> extends in a direction which intersects the longitudinal axis of the second lumen <NUM>. In this case, when the hook <NUM> moves toward the proximal side, the end portion <NUM> comes into contact with the inclination of the distal end surface <NUM> of the sheath <NUM> and slides, and thus the second end portion <NUM> of the hook <NUM> is easily accommodated in the second lumen <NUM>.

As for the shape of the distal end of the sheath in each of the examples and the modified examples, the distal end surface 27F of the sheath 2F may be inclined to have a tapered shape as in an eleventh modified example shown in <FIG>. Since the distal end surface 27F of the sheath 2F is inclined to have a tapered shape in this way, the sheath 2F is easily inserted into the duodenal papilla Dp.

A guide wire holder <NUM> according to an embodiment of the invention will be described with reference to <FIG>. The guide wire holder <NUM> according to the embodiment is different from the first example in the constitution of the distal end portion. Therefore, only the distal end portion of the guide wire holder <NUM> is shown, and the description of the operation portion will be omitted. Further, in the following description, the same components as those already described will be designated by the same reference numerals, and redundant description thereof will be omitted.

<FIG> is a side view showing the distal end portion of the guide wire holder <NUM> according to the embodiment. <FIG> is a cross-sectional view taken along the central axis O of <FIG> is a cross-sectional view taken along line XXXII-XXXII in <FIG>.

The guide wire holder <NUM> according to the embodiment is different from that of the first example in the constitution of the hook. A hook <NUM> is a three-dimensional member fixed to a distal end portion of an operation wire <NUM>. The hook <NUM> has a substantially cylindrical outer shape, and a slit <NUM> is formed in the direction of the longitudinal axis L. As shown in <FIG>, an R surface <NUM> is formed on an outer peripheral portion of a distal end portion <NUM> of the hook <NUM>. As shown in <FIG>, the slit <NUM> is a groove which opens on the first diameter line R1 on the outer peripheral surface of the hook <NUM> and is recessed in the radial direction. The slit <NUM> is formed to extend over the entire length of the hook <NUM> in the direction of the longitudinal axis L. In the example shown in <FIG>, the slit <NUM> is a groove having a U shape, and a bottom surface of the slit <NUM> is a guide wire engagement surface <NUM>.

As shown in <FIG>, the slit <NUM> opens in a direction opposite to the opening of the groove <NUM> of the sheath <NUM>. That is, the outer peripheral opening portion <NUM> of the groove <NUM> and an opening <NUM> of the slit <NUM> open on the first diameter line R1 and are open in different directions by <NUM> degrees in the circumferential direction. Further, when seen in the direction of the longitudinal axis (in a front view along the longitudinal axis), the guide wire engagement surface <NUM> of the slit <NUM> preferably intersects the curved distal end edge (the ridge line) <NUM> of the groove <NUM> to form a closed region C3. On the other hand, as shown in <FIG>, in the direction of the longitudinal axis L, the bottom portion <NUM> of the groove <NUM> and the guide wire engagement surface <NUM> do not face each other, and the slit <NUM> is located on the distal end side from the distal end edge of the groove <NUM>.

As shown in <FIG>, the guide wire engagement surface <NUM> is inclined to approach an extension line of the central axis O of the sheath <NUM> as it goes from the proximal end of the hook <NUM> toward the distal end. A position of the guide wire engagement surface <NUM> at a proximal end portion <NUM> of the hook <NUM> in the radial direction is located radially outward from a position of the bottom portion <NUM> of the groove <NUM> of the sheath <NUM>. The closed region C3 may be formed as a region which is closed by at least the proximal end portion of the hook <NUM> and the distal end edge <NUM> of the groove <NUM> of the sheath <NUM> when seen in the direction of the longitudinal axis. Therefore, the guide wire GW captured in the closed region C3 can smoothly advance and retract in the closed region C3. As a result, when the distal end portion of the guide wire holder <NUM> is inserted into the duodenum, the sheath <NUM> is capable of being easily advanced along the guide wire GW. The groove <NUM> of the sheath <NUM> is formed on the extension of the inclination of the guide wire engagement surface <NUM>.

The hook <NUM> is a member formed of a resin. The hook <NUM> may be formed of any material which has sufficient strength when it is formed into a small shape in consideration of papilla insertability. When the hook <NUM> is formed of a resin, for example, ABS, PEEK, PSU, PPSU or the like is capable of being used. The hook may be formed of a metal. Further, the hook may be formed by combining a metal and a resin. For example, when an inner wall surface of the slit is formed of a resin, the guide wire GW is capable of being slid smoothly.

As shown in <FIG>, the hook <NUM> has a wire-fixing portion <NUM> into which the operation wire <NUM> is inserted and fixed. The wire-fixing portion <NUM> is provided between the slit <NUM> and the outer peripheral surface of the hook <NUM>. The wire-fixing portion <NUM> has a U-shaped communication hole in which two lumens extending parallel to the direction of the longitudinal axis L communicate with each other at the distal end portion, and the operation wire <NUM> is inserted into the communication hole and then fixed by, for example, an adhesive. A method for fixing the operation wire <NUM> and the wire-fixing portion <NUM> is not limited to the adhesive and may be performed by fitting, crimping, or the like.

As for the operation wire <NUM>, as shown in <FIG>, two operation wires <NUM> extend in the direction of the longitudinal axis L. The two operation wires <NUM> are folded back within the distal end portion of the hook <NUM> and extend parallel toward the proximal side. The constitution in which the two operation wires <NUM> are folded back within the distal end portion of the hook <NUM> is not essential. The operation wires <NUM> are inserted in a first lumen (not shown) of the sheath <NUM> to be able to advance and retract. In the embodiment, both of the two operation wires <NUM> are inserted in the first lumen to be able to advance and retract, and the second lumen of the first example is not included. When the operation wires <NUM> are advanced and retracted respect to the sheath <NUM>, the hook <NUM> can advance and retract with respect to the sheath <NUM>.

The guide wire engagement surface <NUM> of the hook <NUM> and the inner wall surface <NUM> of the groove <NUM> of the sheath <NUM> are disposed so that the guide wire GW is capable of being held between the hook <NUM> and the groove <NUM> to be able to advance and retract. Since the guide wire engagement surface <NUM> of the slit <NUM> is inclined so that the distal end portion of the slit <NUM> is located near the central axis O of the sheath <NUM>, the guide wire GW is held at the distal end portion <NUM> of the hook <NUM> to be located near the central axis O of the sheath <NUM>. As a result, when the distal end portion of the guide wire holder <NUM> is inserted into the duodenum, the sheath <NUM> is capable of being easily advanced along the guide wire GW.

According to the guide wire holder <NUM> of the embodiment, the guide wire GW is capable of being easily hooked by the hook <NUM> by disposing the hook <NUM> at the advanced position. Also, when the guide wire GW is hooked by the hook <NUM>, since the opening <NUM> of the slit <NUM> is capable of being visually recognized under the endoscopic image, the guide wire GW is capable of being easily guided into the slit <NUM> of the hook <NUM>, and the guide wire GW is capable of being easily hooked in the slit <NUM>. Also, in a state in which the guide wire GW is hooked on the guide wire engagement surface <NUM>, the guide wire GW is capable of being inserted into the groove <NUM> of the sheath <NUM> by retracting the hook <NUM> (disposing the hook <NUM> in the retracted position). At this time, preferably, a proximal end surface <NUM> of the proximal end portion <NUM> of the hook <NUM> comes into contact with a distal end surface <NUM> of the sheath <NUM>, and thus the hook <NUM>, particularly the guide wire engagement surface <NUM> is positioned distant from the distal end of the groove <NUM>. In this state, the guide wire GW is held between the guide wire engagement surface <NUM> and the inner wall surface <NUM> of the groove <NUM>. According to the guide wire holder <NUM> according to the embodiment, as in the first example, the sheath <NUM> is capable of being smoothly inserted into the papilla side along the guide wire GW.

Since the guide wire holder <NUM> according to the embodiment is constituted to fix the three-dimensional hook <NUM> having the slit <NUM> to the distal end portion of the operation wire <NUM>, the guide wire GW is capable of being easily captured in the slit <NUM>, and also, when the hook <NUM> is disposed at the retracted position, the guide wire GW is capable of being easily held in the closed region C3 between the guide wire engagement surface <NUM> and the inner wall surface <NUM> of the groove <NUM>. Further, the guide wire GW is capable of being prevented from coming off from the hook <NUM> by disposing the hook <NUM> at the retracted position. As a result, for example, the sheath <NUM> is capable of being smoothly inserted into the papilla side.

Since the guide wire holder <NUM> according to the embodiment has a constitution in which the three-dimensional hook <NUM> is fixed to the operation wire <NUM>, the diameter of the operation wire is capable of being reduced when compared to the case in which the linear hook <NUM> like the operation wire <NUM> of the first example is used. Therefore, a highly flexible operation wire is capable of being used, and flexibility of the operation wire <NUM> inserted into the sheath <NUM> is improved. As a result, the flexibility of the entire guide wire holder <NUM> is significantly improved, and the flexibility of the entire device is capable of being increased. When the flexibility of the entire device is high, operability as a device for cannulation is improved.

The guide wire holder according to the present invention is not limited to the example of the above-described embodiment. For example, the modified examples shown in <FIG> is capable of being provided. In the following description, the same components as those already described will be designated by the same reference numerals, and duplicate description thereof will be omitted.

<FIG> is a perspective view of a distal end portion of a guide wire holder <NUM> according to a first modified example of the embodiment of the invention. <FIG> is a top view of the distal end portion of the guide wire holder <NUM> of the modified example, and <FIG> is a side view of the distal end portion of the guide wire holder <NUM> of the modified example. This modified example is different from the embodiment in the constitution of a hook <NUM>, a sheath <NUM>, and an operation wire <NUM>.

In the embodiment, the example in which the proximal end portion <NUM> of the hook <NUM> is formed in a planar shape is shown. However, in the hook <NUM> of the modified example, a protrusion <NUM> which protrudes further toward the proximal side than the proximal end surface of the hook <NUM> is provided. The protrusion <NUM> is formed in a region in which the wire-fixing portion <NUM> is provided, and the protrusion <NUM> protrudes toward the sheath <NUM> side along the operation wire <NUM>. The protrusion <NUM> includes a contact surface <NUM> which can come into contact with a side surface of the sheath <NUM> when the hook <NUM> is retracted.

A distal end portion of the sheath <NUM> includes the groove <NUM> similarly to the sheath <NUM> of the embodiment. A step portion <NUM> in which a region of a first lumen <NUM> in which the operation wire <NUM> is inserted is recessed toward the proximal side is formed on a distal end surface <NUM> of the sheath <NUM>. The step portion <NUM> has a side surface <NUM> formed by cutting out in a plane shape along the longitudinal axis L. The protrusion <NUM> may be set so that at least one of a proximal end of the protrusion <NUM> of the hook <NUM> or a proximal end surface <NUM> is in contact with the sheath <NUM> when the hook <NUM> is disposed at the retracted position. For example, the protrusion <NUM> may be set so that the hook <NUM>, particularly, the guide wire engagement surface <NUM> is positioned distant from the distal end of the groove <NUM> when the proximal end of the protrusion <NUM> is in contact with the step portion <NUM>. In a state in which the proximal end of the protrusion <NUM> is in contact with the step portion <NUM>, preferably, a slight gap is formed between the proximal end surface <NUM> (excluding the protrusion <NUM>) of the hook <NUM> and the distal end surface <NUM> of the sheath <NUM>. Further, for example, the protrusion <NUM> may be set so that the proximal end surface <NUM> (excluding the protrusion <NUM>) of the hook <NUM> and the distal end surface <NUM> of the sheath <NUM> come into contact with each other. In this case, preferably, a slight gap is formed between the proximal end of the protrusion <NUM> and the step portion <NUM>. In the state in which the hook <NUM> and the sheath are in contact with each other as described above, the guide wire GW is held between the guide wire engagement surface <NUM> and the inner wall surface <NUM> of the groove <NUM>.

The operation wire <NUM> is provided by two operation wires <NUM> and <NUM> extending in the direction of the longitudinal axis L. A first operation wire <NUM> of the two operation wires <NUM> and <NUM> extends linearly to be parallel to the longitudinal axis L, and a second operation wire <NUM> is provided to be bent at a plurality of places to be uneven in the vertical direction in a side view. A proximal end of the first operation wire <NUM> is fixed to the operation slider <NUM> of the operation portion <NUM>. A proximal end of the second operation wire <NUM> is disposed in the first lumen <NUM>. That is, the proximal end of the second operation wire <NUM> is disposed in the first lumen <NUM> without being connected to the operation portion <NUM>. As shown in <FIG>, the first operation wire <NUM> and the second operation wire <NUM> extend to overlap the longitudinal axis L in a top view. The first operation wire <NUM> and the second operation wire <NUM> are inserted through the first lumen <NUM> of the sheath <NUM> to be able to advance and retract. As shown in <FIG>, the first lumen <NUM> has a long elliptical shape at least in the distal end opening portion thereof. The first lumen <NUM> is formed so that a long side 21a of the first lumen <NUM> is parallel to the side surface <NUM>. With such a constitution, the first lumen <NUM> and the side surface <NUM> serve as a restricting portion, and the two operation wires <NUM> and <NUM> and the contact surface <NUM> serve as a restricted portion. As a result, the rotation around the axis is restricted more stably than a constitution in which the operation wire is restricted only by the first lumen <NUM>.

As a result of having a constitution in which the first operation wire <NUM> is connected to the operation portion <NUM> and the proximal end of the second operation wire <NUM> having the unevenness in the vertical direction is not connected to the operation portion <NUM>, the uneven shape in the vertical direction of the second operation wire <NUM> is stably held, and the rotation of the hook <NUM> around the axis is capable of being effectively prevented. That is, when a force is applied to the hook <NUM> in a direction in which the hook <NUM> is pulled toward the proximal side, for example, when the operation slider <NUM> is pulled, it is difficult for an external force to be applied to the second operation wire <NUM>, and deformation of the uneven shape in the vertical direction is prevented. Therefore, when the operation wire has the uneven shape which serves as the restricted portion, the uneven shape is preferably provided on the operation wire of which the proximal end of the operation wire is not connected to the operation portion <NUM> among the two operation wires.

As shown in <FIG>, <FIG>, and <FIG>, an X-ray marker <NUM> which is capable of being visually recognized in an X-ray image is provided at the hook <NUM>. In the modified example, the X-ray marker <NUM> is disposed in a folded-back portion of the distal end portion of the operation wire <NUM> and is embedded in the hook <NUM>.

In the embodiment, the contact surface <NUM> is formed continuously from the inner wall surface of the slit <NUM>, but the contact surface <NUM> may be provided separately from the slit <NUM>. The protrusion <NUM> may be provided at a position different from that of the wire-fixing portion <NUM>.

For example, the constitution of the restricted portion in each of the embodiments and the modified examples is not limited to the above-described aspect. For example, the restricted portion in the embodiment or the first modified example of the embodiment may be changed to the restricted portion having the shape shown in <FIG>.

In the embodiment and the first modified example, since the R surface <NUM> is formed on the outer peripheral portion of the distal end portion <NUM> of each of the hooks <NUM> and <NUM>, the guide wire holders <NUM> and <NUM> is capable of being smoothly advanced and retracted. In addition, the R surface may be also formed on the proximal end portions <NUM> of the hooks <NUM> and <NUM>. Further, as long as the guide wire holder is capable of being smoothly advanced and retracted, shapes of the outer peripheral portions of the distal end portion and the proximal end portion of the hook are not limited to the R surface. For example, it may be a C surface. Further, as in the second modified example shown in <FIG>, the distal end portion <NUM> of the hook may have the R surface <NUM>, and the proximal end portion <NUM> may have the inclined surface <NUM> which is the C surface. In addition, as in the third modified example shown in <FIG>, at the proximal end portion <NUM> of the hook <NUM>, the inclined surface <NUM> which is, for example, the R surface or the C surface may be formed so that a cutout amount increases as it is separated from a portion, to which the operation wire <NUM> is connected, in the radial direction of the hook <NUM>. Since such an inclined surface is formed at the proximal end portion of the hook <NUM>, it is difficult for the hook <NUM> to be caught in the tissue when the hook <NUM> is pulled toward the proximal side. Regarding the hook <NUM> of the embodiment, although an example in which the proximal end surface is flat and the outer peripheral edge portion does not have the inclined surface is shown, as in the fourth modified example shown in <FIG>, the inclined surface <NUM> may also be formed by, for example, the C surface or the R surface in the proximal end portion <NUM> of the hook <NUM> of the embodiment. In the guide wire holder, the inclined surfaces of the proximal end portion and the distal end portion are not essential constitutions.

The protrusion <NUM> shown in the first modified example <NUM> of the embodiment is not an essential constitution.

The X-ray marker is not limited to the aspect shown in the modified example of the embodiment, and at least a part of the hook may be formed of a radiopaque material. For example, the X-ray marker may be provided on the operation wire or may be provided to be exposed on the outer peripheral surface of the hook <NUM>. Alternatively, when the hook itself is formed of a material having radiopacity, the X-ray marker is not essential.

The X-ray marker may be provided on the hook of the first example or the embodiment, or at least a part of the hook may be formed of a material having radiopacity.

The constitution of the operation wire <NUM> of the embodiment and the constitution of the operation wire <NUM> of the modified example may be exchanged.

Although one embodiment of the present invention has been described above, the technical scope of the present invention is defined by the appended claims.

Claim 1:
A guide wire holder (<NUM>), comprising:
a sheath (<NUM>, <NUM>, <NUM>) having a lumen of which a central axis (O) extends along a longitudinal axis (L);
an operation wire (<NUM>) which is inserted through the lumen to be able to advance and retract along the longitudinal axis (L); and
a hook (<NUM>, <NUM>) which is a member fixed to a distal end of the operation wire (<NUM>) and has a slit (<NUM>) formed along the longitudinal axis (L), the hook (<NUM>, <NUM>) protruding from a distal end of the sheath (<NUM>, <NUM>, <NUM>),
wherein the sheath (<NUM>, <NUM>, <NUM>) has a groove (<NUM>) configured to extend from the distal end of the sheath (<NUM>, <NUM>, <NUM>) toward a proximal end side of the sheath (<NUM>, <NUM>, <NUM>),
wherein the groove (<NUM>) is formed to have a concave shape being recessed in a direction orthogonal to the central axis (O) from an outer peripheral surface of the sheath (<NUM>, <NUM>, <NUM>) toward the central axis (O), and the groove (<NUM>) has an inner wall surface (<NUM>) which is a curved surface and a part of the outer peripheral surface of the sheath (<NUM>, <NUM>, <NUM>),
wherein the groove (<NUM>) forms an opening portion which opens to the outer peripheral surface of the sheath (<NUM>, <NUM>, <NUM>),
wherein a bottom surface of the slit (<NUM>) is a guide wire engagement surface (<NUM>, <NUM>) of the hook (<NUM>, <NUM>),
wherein when seen in a front view of the distal end of the sheath (<NUM>, <NUM>, <NUM>), the groove (<NUM>) of the sheath (<NUM>, <NUM>, <NUM>) and the slit (<NUM>) open in directions opposite to each other, and
wherein the guide wire engagement surface (<NUM>, <NUM>) and the inner wall surface (<NUM>) are configured to be capable of capturing and holding the guide wire therebetween in a state in which the guide wire engagement surface (<NUM>, <NUM>) is located closer to a distal side than the groove (<NUM>).