WO2018181962A1

WO2018181962A1 - Leading-end tip for catheter, and stent delivery device

Info

Publication number: WO2018181962A1
Application number: PCT/JP2018/013782
Authority: WO
Inventors: 亮子西岡
Original assignee: 日本ゼオン株式会社
Priority date: 2017-03-31
Filing date: 2018-03-30
Publication date: 2018-10-04
Also published as: CN110352080B; JPWO2018181962A1; CN110352080A; JP7028240B2

Abstract

[Problem] To provide a leading-end tip for a catheter, having exceptional piercing properties. [Solution] A leading-end tip 10 for a catheter has a first member 100 that is connected to the distal end of a catheter 2, and a second member 200 that is fixed so as to protrude in the axial direction from the distal-end surface of the first member 100. The material of the second member 200 is harder than the material of the first member 100, and formed in the first member 100 and/or the second member 200 is at least one anchoring protrusion 141 for engaging with the other of the first member 100 and the second member 200.

Description

End tip for catheter and stent delivery device

The present invention relates to a distal tip and a stent delivery device installed at the distal end of a catheter, and more particularly to a distal tip for a catheter and a stent delivery device that facilitate insertion of the catheter into the body.

In recent years, patients with unresectable malignant biliary strictures or obstructions who require biliary drainage and cannot undergo a transduodenal papilla approach, etc. There are some reports of hepatic biliary drainage (EUS-BD). EUS-BD inserts an ultrasound endoscope into the duodenum (or stomach) and punctures the common bile duct (or intrahepatic bile duct) with a puncture needle from the duodenum (or stomach) wall while observing ultrasound images in real time. Then, after inserting a guide wire into the bile duct through this puncture hole, a tubular object serving as a bypass path connecting the duodenum (or stomach) and the common bile duct (or intrahepatic bile duct) along the guide wire This is a procedure for insertion and detention. This procedure enables biliary drainage by embedding a tubular object in the body.

In some cases, a self-expanding stent provided with a coating film may be used as a tubular material used as a bypass route in such an EUS-BD. As a stent delivery device used in this case, for example, a stent placement section provided with a catheter having an inner sheath and an outer sheath through which the inner sheath is slidably inserted, provided near the distal end of the inner sheath Place the stent on the inner sheath, hold the stent in a state of reduced diameter inside the vicinity of the distal end of the outer sheath, and slide on the proximal end side of the catheter to pull out the outer sheath with respect to the inner sheath In this case, the stent is expanded in diameter.

For example, when bypassing the stomach and the intrahepatic bile duct, puncture with a puncture needle from the stomach wall to the intrahepatic bile duct through the abdominal cavity, a guide wire is inserted, and the puncture hole is inserted into the catheter. After the distal end is expanded with a dilator or the like to the extent that it can be inserted, the distal end (stent placement portion) of the catheter is inserted into the puncture hole, and in this state, the outer sheath is pulled out and the stent is released (exposed / expanded). The stent is placed in the puncture hole.

When inserting a catheter into the stomach or duodenum, it is important not to injure these body lumens. Further, when the distal end of the catheter is inserted through a puncture hole such as the stomach wall or duodenal wall, smooth insertion is important. Therefore, Patent Document 1 proposes a catheter in which a distal tip is provided with a material having a high elastic modulus on the distal side and a material having a low elastic modulus on the proximal side. As a result, the tip has high piercing property (pushability) and flexibility, and the catheter can be smoothly inserted without damaging the body lumen. However, in recent years, a tip having a better piercing property than before has been demanded.

JP 2014-195556 A

The present invention has been made in view of such a situation, and an object thereof is to provide a catheter tip having excellent piercing property.

In order to achieve the above object, a catheter tip according to the present invention comprises:
A first member connected to the distal end of the catheter;
A second member fixed so as to protrude axially from the distal end surface of the first member,
The material of the second member is harder than the material of the first member,
At least one of the first member and the second member is formed with at least one anchor protrusion for engaging with the other of the first member and the second member.

In the catheter tip according to the present invention, the second member formed of a material harder than the material of the first member is fixed so as to protrude in the axial direction from the distal end surface of the first member. Therefore, the distal end portion of the catheter tip is provided with a high piercing property (pushability), and smooth insertion is possible when the distal end portion of the catheter is inserted into the puncture hole. On the other hand, a first member made of a material softer than the material of the second member is connected to the distal end of the catheter. Therefore, the surface on the proximal side of the catheter tip is provided with appropriate flexibility, and stimulation of the body lumen can be reduced when the catheter is inserted into the body lumen.

In addition, in the catheter tip according to the present invention, at least one of the first member and the second member is formed with at least one anchor protrusion for engaging with the other of the first member and the second member. It is. By setting it as such a structure, a 1st member and a 2nd member are firmly connected and it can prevent that one of a 1st member and a 2nd member slips out from the other.

Preferably, the distal end portion of the second member has a tapered curved surface. By adopting such a configuration, the contact area between the distal end portion of the second member and the body lumen is increased by the amount of the curved surface, and the body lumen is highly pressed by the curved surface. Can be pressed. Therefore, the piercing property of the catheter tip can be further enhanced.

Preferably, the joining surface where the distal end of the first member joins the second member is a tapered surface whose diameter increases toward the distal end. By setting it as such a structure, at the time of manufacture of the front-end | tip tip for catheters, it becomes difficult to produce the part into which the resin which comprises a 1st member does not flow into a type | mold, and can improve the moldability of a 1st member.

A catheter having the catheter tip connected to the distal end may be included in the stent delivery device.

FIG. 1 is a front view showing the overall configuration of a stent delivery device having a catheter tip according to a first embodiment of the present invention. 2A is a cross-sectional view showing the distal tip for a catheter shown in FIG. FIG. 2B is a cross-sectional view showing the distal tip for a catheter according to the second embodiment of the present invention. FIG. 2C is a cross-sectional view showing the distal tip for a catheter according to the third embodiment of the present invention. FIG. 2D is a cross-sectional view showing the distal tip for a catheter according to the fourth embodiment of the present invention. FIG. 2E is a perspective view showing the distal tip for a catheter shown in FIG. 2D. FIG. 3 is a view showing an operation (puncture) when the stent is placed in the puncture hole using the stent delivery apparatus shown in FIG. FIG. 4 is a view showing an operation (guide wire insertion) when the stent is placed in the puncture hole using the stent delivery apparatus shown in FIG. FIG. 5 is a view showing an operation (catheter insertion start) when the stent is placed in the puncture hole using the stent delivery device shown in FIG. FIG. 6 is a view showing an operation (while the catheter is being inserted) when the stent is placed in the puncture hole using the stent delivery apparatus shown in FIG. FIG. 7 is a view showing an operation (completion of catheter insertion) when the stent is placed in the puncture hole using the stent delivery device shown in FIG. FIG. 8 is a view showing an operation (while the stent is being released) when the stent is placed in the puncture hole using the stent delivery apparatus shown in FIG. FIG. 9 is a view showing an operation (stent release completion) when the stent is placed in the puncture hole using the stent delivery apparatus shown in FIG. FIG. 10 is a diagram showing the evaluation results of the piercing property of the catheter tip shown in FIG.

First Embodiment Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the present embodiment, a case where a self-expanding stent having a coating film for bypassing the stomach and the intrahepatic bile duct is placed in an ultrasonic endoscope-guided transgastric transhepatic biliary drainage (EUS-BD). An example will be described. However, the present invention is not limited to the bypass connection between the stomach and the intrahepatic bile duct, and can be widely applied to the bypass connection between the luminal organ and other luminal organs such as the duodenum and the common bile duct. In addition, the present invention is not limited to the case where such a stent is placed. For example, transduodenal papillary biliary drainage (where a stent is placed in a narrowed portion in the common bile duct), stenosis in a lumen other than the common bile duct The present invention can also be applied to a device in which a stent is placed in a part.

As shown in FIG. 1, a stent delivery device 1 includes an elongated catheter 2 that is inserted into a patient's body (lumen) via a treatment instrument guide tube of an endoscope (not shown) and a proximal end side of the catheter 2. The operation unit 3, the guide wire 4, the stent 5 as an indwelling object, and the catheter tip 10 (hereinafter simply referred to as the “tip tip 10”) are schematically shown. It is prepared for. Although the vicinity of the distal end of the catheter 2 including the stent 5 may be curved according to the shape of the site to be placed, it is drawn linearly for convenience.

The catheter 2 includes an inner sheath (inner tube) 21 having a distal end and a proximal end, and an outer sheath (outer tube) 22 having a distal end and a proximal end. In the vicinity of the distal ends of the inner sheath 21 and the outer sheath 22, contrast markers (not shown) are respectively attached. A contrast marker is a marker in the body that is detected by fluoroscopy, and is formed of, for example, a metal material such as gold, platinum, or tungsten, or a polymer blended with barium sulfate or bismuth oxide. .

The inner sheath 21 is composed of a flexible elongated tube, and a guide wire 4 used as a guide for inserting the catheter 2 into the patient's body is inserted through the inner sheath 21. After the guide wire 4 is inserted into the body to secure a path between the outside of the body and the inside of the body, the catheter 2 is pushed (advanced) along the guide wire 4 so that the distal end side of the catheter 2 is moved to the target site in the body. Can be inserted. The outer diameter of the inner sheath 21 (the portion where the stent 5 described later is disposed) is about 0.5 to 3.5 mm.

A fixing ring 25 is integrally fixed in the vicinity of the distal end of the inner sheath 21, and this fixing ring 25 is for defining the position of the proximal end of the stent 5. The distal end side portion is a stent placement portion. In the stent placement portion, the stent 5 is placed so as to cover the inner sheath 21. Further, another elongate tube (not shown) is coaxially provided on the proximal end side of the fixing ring 25 of the inner sheath 21 so as to cover the elongate tube constituting the inner sheath 21 main body, A portion of the inner sheath 21 closer to the proximal end than the fixing ring 25 is thicker than a portion of the inner sheath 21 closer to the distal end than the fixing ring 25. Thus, the proximal end side portion of the inner sheath 21 is thicker than the fixing ring 25, so that the pushability of the inner sheath 21 is increased and the operability is improved, and the position of the fixing ring 25 is proximal. Shifting to the end side is prevented.

The outer sheath 22 is made of an elongated tube having flexibility, has an inner diameter slightly larger than the outer diameter of the inner sheath 21, and the inner sheath 21 is slidably inserted in the inner sheath 21. The outer diameter of the outer sheath 22 is about 0.5 to 3.5 mm, and the outer diameter is about 1.0 to 4.0 mm. The outer sheath 22 is slidable (relatively moved) in the axial direction with respect to the inner sheath 21 by operating the operation unit 3.

Examples of the material of the inner sheath 21 and the outer sheath 22 include polyolefins such as polyethylene and polypropylene, polyvinyl chloride, polyurethane, ethylene-vinyl acetate copolymer, polyesters such as polyethylene terephthalate and polybutylene terephthalate, polyamide, and polyether polyamide. , Polyester polyamide, polyetheretherketone, polyetherimide, various resin materials such as polytetrafluoroethylene and fluororesin such as tetrafluoroethylene / hexafluoropropylene copolymer, polystyrene, polyolefin, polyurethane, polyester It is possible to use various thermoplastic elastomers such as those based on polyamide, polyamide and polybutadiene. Two or more of these can be used in combination.

Although not provided in this embodiment, an outermost tube (not shown) may be coaxially disposed outside the outer sheath 22. The outermost tube is made of an elongated tube having flexibility, and has a lumen into which the outer sheath 22 is slidably inserted. As the outermost tube, a tube having a size about 0.05 to 1.0 mm larger than the outer diameter of the outer sheath 22 can be used. As the material of the outermost tube, polyacetal, polytetrafluoroethylene, tetrafluoroethylene / hexafluoropropylene copolymer, polypropylene or the like can be used.

The stent 5 is a self-expanding covered stent that expands from a contracted state by its own elastic force, and has a cylindrical bare stent formed by a frame and a covering film portion that covers the outer periphery of the bare stent. . The bare stent is made of a superelastic metal such as a nickel titanium alloy, a cobalt chromium alloy, a gold titanium alloy, or a beta titanium alloy, or a shape memory metal. The surface of the bare stent is covered with a coating film spreading so as to fill between adjacent frames, and the outer periphery of the bare stent covered with the coating film is covered with a covering film portion such as a polymer film.

The total length of the stent 5 is determined according to the distance between the luminal organs to be bypassed, and is about 30 to 200 mm. The outer diameter at the time of diameter expansion is the type and size of the luminal organ to be bypassed. Although it is determined depending on the size, it is about φ2 to φ20 mm. The outer diameter of the stent 5 when the diameter is reduced is about a fraction of the outer diameter when the stent 5 is expanded. In the present embodiment, the stent 5 is described as one of the constituent members of the stent delivery device 1, but the stent 5 may be replaceable as a separate member from the stent delivery device 1.

As shown in FIG. 1, the guide wire 4 is used as a guide for inserting the catheter 2 into the patient's body, and is inserted into the lumen of the inner sheath 21, and the distal end thereof is the inner sheath 21. The distal end of the distal tip 10 protrudes from the opening at the distal end thereof, and the proximal end thereof is exposed to the outside through the opening 21 a at the proximal end of the inner sheath 21 disposed through the operation portion 3. Has been placed. In general, a guide wire having a diameter of 0.035 inch (≈0.889 mm) or a diameter of 0.025 inch (≈0.635 mm) is used. In this embodiment, the guide wire is used. 4, the diameter of 0.025 inch is used.

The operation unit 3 includes a substantially cylindrical release handle (housing) 31, and the distal end side opening of the release handle 31 is integrally formed with a distal end side lid member having a through hole at the center thereof. The opening on the proximal end side is closed by being attached integrally with a distal end side lid member having a through hole at the center thereof.

The proximal end portion of the outer sheath 22 is slidably inserted into the through hole of the distal end side lid member of the release handle 31, and the proximal end of the outer sheath 22 is located inside the release handle 31. On the side wall of the release handle 31, a groove penetrating inward and outward in a direction along the central axis is formed. The foot of the release lever 32 having a head positioned outside the release handle 31 and a foot standing upright at the center of the head is disposed through the groove.

The distal end (lower end) of the foot of the release lever 32 is fixed to the proximal end of the outer sheath 22 positioned inside the release handle 31, and the release lever 32 is moved along the groove. The outer sheath 22 can be slid to the proximal end side or the distal end side with respect to the inner sheath 21 fixed to the release handle 31 (proximal end side lid member).

The proximal end portion of the inner sheath 21 inserted through the outer sheath 22 passes through the release handle 31, passes through the through hole of the proximal end side lid member of the release handle 31, and the proximal end thereof is the release handle. 31 is located outside. The inner sheath 21 is fixed to the proximal end side lid member (release handle 31) at the portion of the through hole. In addition, the release handle 31 is provided with an injection port 33. By connecting a syringe to the injection port 33 and feeding physiological saline or the like, the outer handle is provided through the injection port 33 and the lumen of the release handle 31. Saline or the like can be injected into the lumen of the sheath 22 (outside the inner sheath 21).

In a state where the release lever 32 is moved to the distal end of the groove, the distal end of the outer sheath 22 reaches the distal tip 10, and in this state, the stent 5 disposed in the stent placement portion of the inner sheath 21 is moved. It is in a state of being held in its reduced diameter state. When the release lever 32 is moved to the proximal end side of the groove from this state, the outer sheath 22 is slid toward the proximal end side with respect to the inner sheath 21, and the stent 5 is moved to the distal end of the outer sheath 22. And the stent 5 is released (expanded diameter) by the self-expanding force.

The tip 10 is attached to the distal end of the inner sheath 21. The tip 10 reduces the stimulation of the body lumen when the distal end of the inner sheath 21 (catheter 2) hits the peripheral wall of the body lumen, and further reduces the insertion resistance of the catheter 2. It plays a role in facilitating insertion into the body.

As shown in FIG. 2A, the tip 10 includes a first member 100 connected to the distal end of the inner sheath 21, and a second member fixed so as to protrude in the axial direction from the distal end surface of the first member 100. 200, and each

member

100, 200 is coupled.

The ratio L1 / L between the total length L1 of the first member 100 in the axial direction and the total length L of the tip 10 is preferably 0.65 to 0.95. The ratio between the total axial length L2 of the second member 200 and the total length L of the tip 10 is preferably 0.2 to 0.4.

Inside the first member 100 and the second member 200, a cylindrical inner space 160 which is a cylindrical space penetrating each

member

100, 200 in the axial direction is formed. As shown in FIG. 2A, the distal end of the inner sheath 21 pushes the inner wall of the cylindrical inner space 160 in the vicinity of the center in the axial direction of the first member 100 inside the cylindrical inner space 160. Until inserted. A guide wire 4 (not shown) that passes through the lumen of the inner sheath 21 passes through the inside of the cylindrical inner space 160 and protrudes from the opening at the distal end of the second member 200. The inner diameter of the cylindrical inner space 160 is substantially the same as the diameter of the guide wire, for example.

The first member 100 has a small diameter portion 110, a proximal taper portion 120, a large diameter portion 130, and a distal taper portion 140. The small-diameter portion 110 is a portion on the proximal end side of the tip 10 and is a small-diameter cylindrical portion to which the distal end portion of the inner sheath 21 is connected. A curved surface 111 that is tapered toward the proximal side is formed at the proximal end of the small diameter portion 110.

The proximal taper portion 120 is disposed on the distal side of the small-diameter portion 110 and gradually increases from the proximal side (the side where the small-diameter portion 110 is present) to the distal side (the side where the second member 200 is present). It is a taper surface part inclined so that an outer diameter may become large. In the present embodiment, the proximal tapered portion 120 is formed so that the tapered surface is gently inclined.

The large diameter portion 130 is disposed on the distal side of the proximal taper portion 120, forms an intermediate portion of the tip tip 10, and is formed in a cylindrical shape having a larger diameter than the small diameter portion 110 and the proximal taper portion 120. This is the thickest part of the tip 10. The outer diameter of the large diameter portion 130 is preferably 1.1 to 1.4 times the outer diameter of the small diameter portion 110.

The distal taper portion 140 is a tapered surface portion that is disposed on the distal side of the large diameter portion 130 and is inclined so that the outer diameter gradually decreases from the proximal side toward the distal side. In this embodiment, the taper surface of the distal taper portion 140 includes a proximal first taper surface 143 and a distal second taper surface 144 according to the inclination angle. The distal end portion of the catheter 2 is smoothly inserted into the body lumen and pushed forward by the action of the outer peripheral surface of the distal taper portion 140 comprising these taper surfaces 143 and 144. Note that a plurality of tapered surfaces may be further formed on the outer peripheral surface of the distal tapered portion 140.

At the distal end of the distal taper portion 140, a distal end surface 142 made of a surface perpendicular to the axial direction of the tip 10 is formed. The distal end surface 142 is a joint surface where the distal end of the first member 100 is joined to the second member 200.

On the distal side of the distal taper portion 140, an anchor convex portion 141 that protrudes radially inward is formed. The anchor convex portion 141 can be engaged with the second member 200 (more specifically, an anchor concave portion 221 described later).

The distal taper portion 140 is formed with a fitting cylindrical portion 170 into which the proximal side of the second member 200 (more specifically, a base end portion 220 described later) is fitted. As shown in FIG. 2A, the insertion cylindrical portion 170 has a proximal cylindrical region 171 composed of a cylindrical surface parallel to the axial direction and an outer diameter gradually from the proximal side toward the distal side. It has an intermediate cylindrical region 172 composed of a tapered surface inclined so as to be small, and a distal cylindrical region 173 composed of a cylindrical surface parallel to the axial direction. The tapered surface in the intermediate cylindrical region 172 is not limited to a tapered surface having an inclination angle as shown in the figure, and the outer diameter difference between the proximal cylindrical region 171 and the distal cylindrical region 173 is not limited. Any other shape may be used as long as the shape is formed. For example, the tapered surface may be a stepped surface or a stepped surface perpendicular to the axial direction of the tip 10.

The second member 200 has a protruding portion 210 and a base end portion 220. The protruding portion 210 is a portion protruding in the axial direction from the distal end surface of the first member 100. The thickness of the distal end portion of the projecting portion 210 is determined so as not to bend when the tip 10 presses the body lumen, and is preferably 0.1 to 0.3 mm. L21 / L2 between the axial length L21 of the protrusion 210 and the total axial length L2 of the second member 200 is preferably 0.2 to 0.7. When inserting the catheter 2 into the body lumen, the value of L21 / L2 should be as large as possible from the viewpoint of ensuring the piercing property of the distal tip 10, and from the viewpoint of reducing stimulation to the body lumen, L21 / L2 The smaller the value, the better.

As shown in FIG. 2A, the protrusion 210 has a tapered surface inclined so that the outer diameter gradually decreases from the proximal side toward the distal side, and a tapered curve is formed at the distal end thereof. It has a surface 211. The radius of curvature of the curved surface 211 is preferably 0.07 to 0.30 mm, and more preferably 0.07 to 0.25 mm.

The proximal end portion 220 is disposed on the proximal side of the protruding portion 210 and forms a proximal portion of the second member 200. The ratio L22 / L2 between the axial length L22 of the base end portion 220 and the total axial length L2 of the second member 200 is preferably 0.3 to 0.8.

An anchor recess 221 that is recessed radially inward is formed on the distal side of the base end portion 220. The anchor concave portion 221 can be engaged with the anchor convex portion 141 of the first member 100. The axial length L23 of the anchor concave portion 221 is substantially the same as the axial length of the anchor convex portion 141, and the axial length L23 of the anchor concave portion 221 and the total length L2 of the second member 200 in the axial direction are the same. The ratio L23 / L2 is preferably 0.2 to 0.4.

The base end portion 220 is inserted into the insertion cylindrical portion 170, and the insertion portion is joined (connected) by an adhesive or by fusion. At that time, the first protrusion 100 and the second member 200 are firmly connected by engaging the anchor protrusion 141 with the anchor recess 221, so that one of the first member 100 and the second member 200 is the other. Can be prevented from coming off.

In the present embodiment, the second member 200 is formed of a material harder than the first member 100. More specifically, the material of the first member 100 has a Shore A hardness (JIS K 6253) of preferably 30 to 100, more preferably 35 to 95. The material of the second member 200 has a Shore D hardness (JIS K 6253) of preferably 60 to 80.

Specifically, the first member 100 and the second member 200 are each made of a resin such as polyethylene, polyamide, or polyurethane, and among these various resin materials, materials having different hardness (Shore A hardness). In this case, a material that can be appropriately bonded and fused is selected, and the second member 200 is formed of a relatively hard material, and the first member 100 is formed of a relatively soft material.

The entire outer peripheral surface of the tip 10 is lubricated. As a result, the entire outer peripheral surface of the tip 10 including the portion of the large-diameter portion 130 is formed to be slippery, facilitating insertion of the catheter 2. In addition, as an example of the lubricity treatment applied to the tip 10, a hydrogel coating or the like can be used in addition to a fluororesin coating or a silicone oil coating.

In addition, the molding method for molding such a tip 10 is not particularly limited, but can be manufactured by, for example, two-color injection molding from two directions, insert injection molding, or the like. Moreover, the 1st member 100 and the 2nd member 200 can each be shape | molded separately, and they can also be joined by adhesion | attachment or welding.

Next, a procedure for placing a stent using the stent delivery device of this embodiment will be described with reference to FIGS. For example, when a stent is placed so as to bypass the stomach and intrahepatic bile duct in the abdominal cavity, a puncture needle 73 extends from the stomach wall 71 through the abdominal cavity 75 to the bile duct wall 72 as shown in FIG. Puncturing is performed to form puncture holes 74 in both the stomach and the intrahepatic bile duct. Thereafter, by inserting the guide wire 4 into the lumen of the puncture needle 73 and then removing the puncture needle 73 from the puncture hole 74, the guide wire 4 is inserted into the puncture hole 74 as shown in FIG. Secure a route. 3 to 9, the endoscope is indicated by a two-dot chain line.

Next, after the puncture hole 74 is expanded by a dilator (not shown), the release lever 32 of the operation unit 3 is moved to the distal end of the groove, and the outer sheath 22 is slid to the distal end side, That is, as shown in FIG. 5, the distal end of the catheter 2 in a state in which the stent 5 disposed in the stent placement portion of the inner sheath 21 is held inside the distal end portion of the outer sheath 22 in a reduced diameter state. The end (the protruding portion 210 of the tip 10) is inserted into the puncture hole 74 on the stomach wall 71 side. Since the outer diameter of the protrusion 210 of the distal tip 10 is sufficiently small and hard, the distal tip 10 has a high piercing property and can be easily inserted into the puncture hole 74 on the stomach wall 71 side.

Next, as shown in FIG. 6, when the catheter 2 (the inner sheath 21 and the outer sheath 22) is inserted so that the distal tip 10 passes through the puncture hole 74 on the stomach wall 71 side and is inserted deeper into the abdominal cavity 75. The puncture hole 74 on the gastric wall 71 side is gradually expanded by the distal taper portion 140 of the tip 10, and the puncture hole 74 on the stomach wall 71 side can be inserted by the distal tip 10 into the distal end of the catheter 2. To be expanded. Thereafter, the catheter 2 is further advanced, and the distal end portion of the catheter 2 (the protruding portion 210 of the tip 10) is inserted into the puncture hole 74 on the bile duct wall 72 side. Since the outer diameter of the protruding portion 210 of the distal tip 10 is sufficiently small and hard, the distal tip 10 has a high piercing property, and the puncture hole on the bile duct wall 72 side is the same as the puncture hole 74 on the stomach wall 71 side. 74 can be easily inserted.

When the catheter 2 is further advanced, the puncture hole 74 on the bile duct wall 72 side is gradually expanded by the distal taper portion 140 of the tip tip 10, and the puncture hole 74 on the bile duct wall 72 side is inserted by the tip tip 10 into the catheter 2. The distal end is expanded to allow insertion. The catheter 2 is further advanced, and the catheter 2 is inserted with the distal end of the stent 5 positioned inside the bile duct wall 72 and the proximal end of the stent 5 positioned inside the stomach wall 71 as shown in FIG. To stop.

Thereafter, in the operation unit 3, the release lever 32 is moved to the proximal end side of the groove, and the outer sheath 22 is slid toward the proximal end side with respect to the inner sheath 21, as shown in FIG. As the outer sheath 22 slides toward the proximal end side, the stent 5 is gradually exposed and expanded from its distal end side, and the release lever 32 is moved to the proximal end of the groove, as shown in FIG. In addition, the stent 5 is in a state of being entirely exposed and expanded in diameter. Thereafter, the catheter 2 and the distal tip 10 are passed through the inside of the expanded stent 5 and pulled out, whereby the placement of the stent 5 is completed.

In the catheter tip 10 according to the present embodiment, the second member 200 formed of a material harder than the material of the first member 100 is fixed so as to protrude in the axial direction from the distal end surface of the first member 100. . Therefore, the distal end portion of the catheter tip 10 has a high piercing property (pushing property), and when the distal end portion of the catheter 2 is inserted through the puncture hole 74, smooth insertion is possible. On the other hand, the first member 100 made of a material softer than the material of the second member 200 is connected to the distal end of the catheter 2. Therefore, the proximal surface of the catheter tip 10 is provided with appropriate flexibility, and when the catheter 2 is inserted into the body lumen, stimulation to the body lumen can be reduced.

In addition, in the catheter tip according to the present embodiment, the first member 100 is formed with an anchor convex portion 141 for engaging with the second member 200. Therefore, the first member 100 and the second member 200 are firmly connected, and one of the first member 100 and the second member 200 can be prevented from coming off from the other.

Further, the distal end portion of the second member 200 has a curved surface 211 that is tapered. Therefore, the contact area between the distal end portion of the second member 200 and the body lumen is increased by the amount of the curved surface, and the body lumen can be pressed with a high pressing force by the curved surface. It becomes. Therefore, the piercing property of the catheter tip 10 can be further enhanced.

Second Embodiment The tip 10A of the present embodiment shown in FIG. 2B has the same configuration and operational effects as those of the first embodiment described above, except for the following points, and the description of the common parts is omitted. In the drawings, common member symbols are assigned to common members. As shown in FIG. 2B, the tip 10A includes a first member 100A and a second member 200A.

1st member 100A is the same as that of the 1st member 100 in a 1st embodiment except having replaced with distal taper part 140 and having distal taper part 140A. More specifically, the distal taper portion 140 has an anchor convex portion 141A. The second tapered surface 144A is formed such that its axial length is shorter than the axial length of the second tapered surface 144 in the first embodiment.

The anchor convex portion 141A is formed such that its axial length is shorter than the axial length of the anchor convex portion 141 in the first embodiment. A distal end surface 142A formed at the distal end of the anchor convex portion 141A is a tapered surface whose diameter increases toward the distal end. With the above configuration, as shown in FIG. 2B, the distal end portion of the distal taper portion 140 A is thicker than the distal end portion of the distal taper portion 140.

The second member 200A is the same as the second member 200 in the first embodiment except that it has a protruding portion 210A instead of the protruding portion 210 and has a proximal end portion 220A instead of the proximal end portion 220.

More specifically, as shown in FIG. 2B, the protrusion 210A has a length in the axial direction that is longer on the proximal side than the length in the axial direction of the protrusion 210, and has an outer periphery that is parallel to the axis. It is formed so as to be a cylindrical shape. The curved surface 211 A is formed so that its radius of curvature is larger than the radius of curvature of the curved surface 211.

The base end 220A has an anchor recess 221A. The anchor recess 221A is formed such that its axial length is shorter than the axial length of the anchor recess 221 by an increment of the axial length of the protrusion 210A.

In this embodiment, the same effect as that of the first embodiment can be obtained. In addition, in the present embodiment, since the distal end portion of the distal taper portion 140A is thick, it is difficult to produce a portion in which the resin constituting the first member 100 does not easily flow into the mold when the tip chip 10 is manufactured. The moldability of the first member 100 can be improved.

Third Embodiment The tip 10B of the present embodiment shown in FIG. 2C has the same configuration and operational effects as those of the second embodiment described above except for the following points, and the description of the common parts is omitted. In the drawings, common member symbols are assigned to common members. As shown in FIG. 2C, the tip 10B includes a first member 100B and a second member 200B.

The second member 200B is the same as the second member 200A in the second embodiment except that the second member 200B has a base end portion 220B instead of the base end portion 220A. More specifically, the proximal end portion 220B has an axial length longer on the proximal side than the axial length of the proximal end portion 220 in the second embodiment, and the proximal end portion has an anchor protrusion. A portion 222B is formed.

The anchor convex portion 222B is formed in a convex shape protruding outward in the radial direction so as to be able to engage with the first member 100B (more specifically, an anchor concave portion 131B described later). The function of the anchor convex portion 222B is the same as the function of the anchor convex portion 141A in the second embodiment.

The first member 100B has a large-diameter portion 130B instead of the large-diameter portion 130, and has the distal-side tapered portion 140B instead of the distal-side tapered portion 140, the first member 100A in the second embodiment. It is the same. More specifically, the distal taper portion 140B is formed so that the fitting insertion tubular portion 170B extends to the proximal side.

The large diameter portion 130B has an anchor recess 131B. The anchor recess 131 B has a concave shape that is recessed outward in the radial direction so that the anchor recess 131 B can engage with the anchor protrusion 222 B of the second member 200. The function of the anchor recess 131B is the same as the function of the anchor recess 221A in the second embodiment.

In this embodiment, the same effect as that of the second embodiment can be obtained. In addition, in the present embodiment, the first member 100B is formed with an anchor concave portion 131B in addition to the anchor convex portion 141A, and the second member 200B is formed with an anchor convex portion 222B in addition to the anchor concave portion 221A. Has been. Therefore, in addition to the anchor convex portion 141A engaging with the anchor concave portion 221A, the anchor convex portion 131B engages with the anchor concave portion 222B, and the first member 100B and the second member 200B are firmly connected. One of the first member 100B and the second member 200B can be reliably prevented from coming off from the other.

Tip 10C of the present embodiment shown in Fourth Embodiment FIG. 2D, except that the following have the same configuration and operation effect as the first embodiment described above, a description of common parts is omitted, In the drawings, common member symbols are assigned to common members. As shown in FIG. 2D, the tip 10C has a first member 100C and a second member 200C.

The second member 200C is the same as the second member 200 in the first embodiment, except that the protruding portion 210C is replaced with the protruding portion 210, and the proximal end portion 220C is replaced with the proximal end portion 220C.

The protrusion 210C is formed such that its axial length is longer on the distal side than the axial length of the protrusion 210 in the first embodiment. An intermediate tapered surface 212C is formed on the outer peripheral surface on the proximal side of the protruding portion 210C. The intermediate tapered surface 212C is a tapered surface that is inclined so that the outer diameter gradually decreases from the proximal side toward the distal side. The inclination angle of the intermediate taper surface 212C is substantially equal to the inclination angle of the distal taper portion 140C of the first member 100C. Of the protrusion 210C, the portion where the intermediate tapered surface 212C is formed is formed such that the axial length thereof is substantially equal to the axial length of the portion where the intermediate tapered surface 212C is not formed. Yes.

By providing the intermediate taper surface 212C on the second member 200C, the outer peripheral surface of the second member 200C can be smoothly connected to the outer peripheral surface of the first member 100C at a relatively gentle inclination angle. As a result, the distal end portion (projecting portion 210C) of the catheter is smoothly inserted into the body lumen and pushed forward by the action of the intermediate tapered surface 212C. In addition to the intermediate tapered surface 212C, a plurality of tapered surfaces may be formed on the outer peripheral surface on the proximal side of the protruding portion 210C.

The base end portion 220C has an anchor concave portion 221C and an anchor convex portion 222C. The anchor recess 221 C has a concave shape that is recessed radially inward so as to be able to engage with the first member 100 C (more specifically, an anchor protrusion 141 C described later). Unlike the anchor recess 221A shown in FIG. 2C, for example, the anchor recess 221C is formed such that the recess wall surface is vertical.

The anchor convex portion 222C has a convex shape protruding outward in the radial direction so as to be able to engage with the first member 100C (more specifically, an anchor concave portion 145C described later). Unlike the anchor protrusion 222B shown in FIG. 2C, the anchor protrusion 222C is formed so that the wall surface of the protrusion is vertical.

The first member 100C is the same as the first member 100 in the first embodiment except that the first member 100C has a proximal taper portion 120C and a distal taper portion 140C. The distal tapered portion 140C has the first tapered surface 143C, but does not have a configuration corresponding to the second tapered surface 144 shown in FIG. 2A.

The first tapered surface 143C is formed such that its axial length is longer on the distal side than the axial length of the first tapered surface 143 in the first embodiment shown in FIG. 2A. More specifically, the first tapered surface 143 shown in FIG. 2A extends toward the boundary with the second tapered surface 144 toward the distal side, whereas the first tapered surface 143C shown in FIG. The second member 200C extends to the boundary with the intermediate tapered surface 212C toward the side.

An anchor convex portion 141C and an anchor concave portion 145C are formed on the distal taper portion 140C. The anchor convex portion 141 C has a shape protruding radially inward so as to be able to engage with the anchor concave portion 221 C of the second member 200. Unlike the anchor protrusion 141A shown in FIG. 2C, for example, the anchor protrusion 141C is formed so that the wall surface of the protrusion is vertical.

The anchor recess 145C has a concave shape that is recessed outward in the radial direction so that the anchor recess 145C can be engaged with the anchor protrusion 222C of the second member 200C. Unlike the anchor recess 131B shown in FIG. 2C, the anchor recess 145C is formed such that the recess wall surface is vertical.

As shown in FIG. 2E, a notch 121C is formed at the proximal end of the proximal taper 120C. The cutout part 121C is formed so as to cut out a part of the outer peripheral surface of the proximal taper part 120C from the proximal side toward the distal side. In the illustrated example, only one notch 121C is formed, but a plurality of notches 121C may be formed. When the distal tip 10C is used as the distal tip of the stent delivery device 1 as shown in FIG. 1 by forming the notch 121C in the proximal taper portion 120C, the distal end of the outer sheath 22 becomes the distal tip 10C. It is possible to inject (flush) physiological saline or the like from the injection port 33 into the lumen of the outer sheath 22 in a contact state (a state in which the reduced diameter stent 5 is held in the outer sheath 22).

In this embodiment, the same effect as that of the first embodiment can be obtained. In addition, in this embodiment, since the anchor convex portion 141C engages with the anchor concave portion 221C and the anchor convex portion 222C engages with the anchor concave portion 145C, the first member 100C and the second member 200C are firmly connected. Thus, it is possible to reliably prevent one of the first member 100C and the second member 200C from coming out of the other.

It should be noted that the present invention is not limited to the above-described embodiment, and can be variously modified within the scope of the present invention.

For example, the shape of the distal end of the protruding portion 210 of the tip 10 is not limited to the example shown in FIG. 2A. For example, the distal end is provided with irregularities and grooves, or is jagged, or on the proximal side. Fork shapes may be formed by providing extending cuts.

The inclination angle of the first taper surface 143 and the second taper surface 144 formed on the outer periphery of the distal taper portion 140 may be appropriately changed. Moreover, you may change suitably the inclination-angle of the taper surface formed in the outer periphery of the proximal taper part 120. FIG.

In the example shown in FIG. 2A and the like, the second taper surface 144 of the distal taper portion 140 and the outer peripheral surface of the protrusion 210 are continuously (smoothly) connected, but are intermittently connected. Also good. Further, a stepped surface or stepped surface perpendicular to the axial direction of the tip 10 may be formed at the boundary between the outer peripheral surface of the distal taper portion 140 and the outer peripheral surface of the protruding portion 210.

In the above embodiment, three or more pairs of anchor convex portions and anchor concave portions may be formed. In this case, the 1st member 100 and the 2nd member 200 are connected more firmly, and it can prevent effectively that one of the 1st member 100 and the 2nd member 200 slips out from the other.

Hereinafter, the present invention will be described in more detail with specific examples, but the present invention is not limited to these examples.

Example A polyurethane resin (trade name: Tecoflex EG93A-B40, manufactured by Lubrizol) having a Shore A hardness (JIS K 6253) of 95 is formed on the first member 100 (total length L1 = 10 mm) of the tip 10. The second member 200 (total length L2 = 3.4 mm) molded from a polyurethane resin having a Shore D hardness (JIS K 6253) of 67 (trade name: Tecoflex EG72D-B40, manufactured by Lubrizol) The first member 100 and the second member 200 were welded to produce a sample of the tip 10 having a total length (L) of 11 mm and an axial length (L21) of the protruding portion 210 of 1 mm.

First length is set so that the total length (L2) of the second member 200 of the comparative example is 2.4 mm and the protruding portion 210 does not protrude in the axial direction from the distal end of the first member 100 (L21 = 0 mm). A sample similar to the example was manufactured except that it was fixed inside the member 100.

A load test was performed on each sample composed of the inner sheath 21 and the tip 10 that were produced by evaluation .

This load test was conducted as follows. That is, first, the samples were lowered in the vertical direction, and the tip surfaces (curved portions 211) of the projecting portions 210 of the samples were pressed against the vinyl chloride sheet. In the meantime, the load applied to the protruding portion 210 of each sample was measured with a load meter, and the relationship between the descending distance and the load was obtained. The results of this load test are shown in FIG. 10 with the example as a solid line and the comparative example as a dotted line.

In the evaluation of the load test, the sample of the example had a maximum load of about 0.90N, whereas the sample of the comparative example had a maximum load of about 1.4N. That is, it was confirmed that the piercing property was significantly improved in the sample of the example as compared with the sample of the comparative example.

DESCRIPTION OF SYMBOLS 1 ... Stent delivery apparatus 2 ... Catheter 21 ... Inner sheath 21a ... Opening 22 ... Outer sheath 25 ... Fixing ring 3 ... Operation part 31 ... Release handle 32 ... Release lever 33 ... Injection port 4 ... Guide wire 5 ...

Stent

10, 10A, 10B, 10C ...

tip

100, 100A, 100B, 100C ... first member 110 ... small diameter part 111 ...

curved surface

120, 120C ... proximal taper part 121C ... notch

part

130, 130B ...

large diameter part

140, 140A, 140B, 140C ...

Distal taper portion

141, 141A, 141C, 222B, 222C ... Anchor

convex portion

142, 142A ...

Distal end surface

143, 143C ...

First taper surface

144, 144A ... Second taper surface 160 ... Inside cylindrical Empty part 70, 170B ... Inserted cylindrical portion 171 ... Proximal cylindrical region 172 ... Intermediate cylindrical region 173 ... Distal

cylindrical region

200, 200A, 200B, 200C ...

Second member

210, 210A, 210C ...

Projection

211, 211A ... curved surface 212C ... intermediate tapered

surface

220, 220A, 220B, 220C ...

proximal end

145C, 221, 221A, 131B, 221C ... anchor recess 71 ... gastric wall 72 ... bile duct wall 73 ... puncture needle 74 ... puncture hole 75 ... abdominal cavity

Claims

A first member connected to the distal end of the catheter;
A second member fixed so as to protrude axially from the distal end surface of the first member,
The material of the second member is harder than the material of the first member,
At least one of the first member and the second member is formed with at least one anchor protrusion for engaging with the other of the first member and the second member. Tip for use.
The distal tip for a catheter according to claim 1, wherein a distal end portion of the second member has a tapered curved surface.
3. The catheter tip according to claim 1, wherein a joining surface at which the distal end of the first member joins the second member is a tapered surface whose diameter increases toward the distal end. Chip.
A stent delivery device having a catheter having the distal end tip for a catheter according to any one of claims 1 to 3 connected to a distal end.