JP7028240B2 - Catheter tip and stent delivery device - Google Patents

Description

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

In recent years, in cases of unresectable malignant biliary stricture or obstruction that require biliary drainage, such as when transduodenal papilla approach is not possible, endoscopic ultrasonography-guided transduodenal (or transgastric) There are some reports of (hepatic) biliary drainage (EUS-BD). EUS-BD inserts an endoscopic ultrasound into the duodenum (or stomach) and punctures the common bile duct (or intrahepatic bile duct) from the duodenum (or stomach) wall with a puncture needle while observing ultrasonic images in real time. Then, after inserting the guide wire into the bile duct through this puncture hole, a tubular object that serves as a bypass route connecting the inside of the duodenum (or stomach) and the inside of the common bile duct (or intrahepatic bile duct) along the guide wire is formed. It is a procedure to insert and detain. This procedure enables biliary drainage by implanting a tubular object in the body.

As a tubular object used as a bypass route in such EUS-BD, a self-expandable stent provided with a coating film may be used. The stent delivery device used in this case includes, for example, a catheter having an inner sheath and an outer sheath through which the inner sheath is slidably inserted, and a stent placement portion provided near the distal end of the inner sheath. A stent is placed in the catheter to hold the stent in a reduced diameter inside near the distal end of the outer sheath, and slide to pull out the outer sheath with respect to the inner sheath on the proximal end side of the catheter. It is known that the diameter of the stent is expanded by allowing the stent to be expanded.

For example, in the case of bypass connection between the stomach and the intrahepatic bile duct, a puncture needle is used to puncture the stomach wall through the abdominal cavity to the intrahepatic bile duct, a guide wire is inserted to secure a route, and the puncture hole is catheterized. After expanding the distal end with a dilator or the like to the extent that the distal end 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). By making the diameter), a stent is placed in the puncture hole.

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

Japanese Unexamined Patent Publication No. 2014-195556

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

In order to achieve the above object, the tip for a catheter according to the present invention is
The first member connected to the distal end of the catheter and
It has a second member, which is fixed so as to protrude in the axial direction 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 tip for a catheter according to the present invention, a second member made of a material harder than the material of the first member is fixed so as to protrude axially from the distal end surface of the first member. Therefore, the distal end of the tip for the catheter has a high piercing property (pushing property), and smooth insertion is possible when the distal end 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 tip for the catheter has appropriate flexibility, and when the catheter is inserted into the lumen of the body, irritation to the lumen of the body can be reduced.

In addition, in the tip for a catheter according to the present invention, at least one of the first member and the second member has at least one anchor protrusion for engaging with the other of the first member and the second member. It has been done. With such a configuration, the first member and the second member are firmly connected, and one of the first member and the second member can be prevented from coming off from the other.

Preferably, the distal end of the second member has a tapered curved surface. With such a configuration, the contact area between the distal end of the second member and the internal lumen is increased by the amount of this curved surface, and the curved surface exerts a high pressing force on the internal lumen. It is possible to press with. Therefore, the piercing property of the tip for the catheter can be further enhanced.

Preferably, the joint 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. With such a configuration, it is difficult for the resin constituting the first member to flow into the mold at the time of manufacturing the tip for the catheter, and the moldability of the first member can be improved.

The stent delivery device may be equipped with a catheter to which the tip for the catheter is connected to the distal end.

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

First Embodiment Hereinafter, the embodiment of the present invention will be specifically described with reference to the drawings. In the present embodiment, in endoscopic ultrasonographic guided transgastric transhepatic biliary drainage (EUS-BD), a self-expandable stent having a covering film for bypass connecting the stomach and the intrahepatic bile duct is placed. Let's take an example. 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. Further, the present invention is not limited to the case where such a stent is placed, for example, transduodenal papillary biliary drainage (a stent is placed in a narrowed portion in the common bile duct), and narrowing in a lumen other than the common bile duct. It can also be applied to those in which a stent is placed in the site.

As shown in FIG. 1, the stent delivery device 1 is an elongated catheter 2 inserted into the patient's body (lumen) via a treatment tool guide tube of an endoscope (not shown) and the proximal end side of the catheter 2. The operation unit 3 for operating the catheter 2 inside the body, the guide wire 4, the stent 5 as an indwelling target, and the tip tip 10 for the catheter (hereinafter, simply referred to as “tip tip 10”) are outlined. It is configured in preparation. The vicinity of the distal end of the catheter 2 including the stent 5 may be curved depending on the shape of the indwelling site, but is drawn linearly for convenience in the figure.

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. Contrast-enhanced markers (not shown) are attached in the vicinity of the distal ends of the inner sheath 21 and the outer sheath 22, respectively. The position of the contrast marker is detected by X-ray fluoroscopy and serves as a marker in the body, 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 made of an elongated tube having flexibility, and a guide wire 4 used as a guide for inserting the catheter 2 into the patient's body is inserted in the lumen thereof. After inserting the guide wire 4 into the body to secure a path between the outside 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 becomes 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 arranged) 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 the fixing ring 25 is for defining the position of the proximal end of the stent 5, from the fixing ring 25. The part on the distal end side is the stent placement part. A stent 5 is arranged in the stent arrangement portion so as to cover the inner sheath 21. Further, another elongated tube (not shown) is coaxially provided on the portion of the inner sheath 21 proximal to the fixing ring 25 so as to cover the elongated tube constituting the inner sheath 21 main body. The portion of the inner sheath 21 on the proximal end side of the fixing ring 25 is thicker than the portion of the inner sheath 21 on the distal end side of the fixing ring 25. Since the portion of the inner sheath 21 on the proximal end side of the fixing ring 25 is thickened in this way, the pushability of the inner sheath 21 is increased and the operability is improved, and the position of the fixing ring 25 is proximal. It is prevented from shifting to the end side.

The outer sheath 22 is made of a flexible elongated tube, has an inner diameter slightly larger than the outer diameter of the inner sheath 21, and the inner sheath 21 is slidably inserted inside the outer sheath 22. The inner 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 can slide (relatively move) 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, polyethylene terephthalate, and polyester such as polybutylene terephthalate, polyamide, and polyether polyamide. , Polyamide polyamide, polyether ether ketone, polyetherimide, various resin materials such as fluororesin such as polytetrafluoroethylene and tetrafluoroethylene / hexafluoropropylene copolymer, and polystyrene-based, polyolefin-based, polyurethane-based, polyester. Various thermoplastic elastomers such as based, polyamide-based, and polybutadiene-based can be used. Two or more of these can be used in combination.

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

The stent 5 is a self-expandable covered stent that expands from a contracted state by its own elastic force, and has a tubular 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, a beta-titanium-based alloy, or a shape memory metal. The surface of the bare stent is covered with a coating film that spreads so as to fill the space between adjacent frames, and the outer periphery of the bare stent covered with the coating film is covered with a coating 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, but is about 30 to 200 mm, and the outer diameter at the time of expansion is the type and size of the luminal organs to be bypassed. It is determined according to the bypass, etc., but 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 diameter is expanded. Although the stent 5 is described as one of the constituent members of the stent delivery device 1 in the present embodiment, 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, is inserted into the lumen of the inner sheath 21, and its distal end is the inner sheath 21. The proximal end of the tip 10 protrudes from the opening of the distal end of the tip 10 and is exposed to the outside through the opening 21a of the proximal end of the inner sheath 21 arranged so as to penetrate the operation portion 3. Have been placed. As the guide wire, a wire having a diameter of 0.035 inch (≈0.889 mm) or a guide wire having a diameter of 0.025 inch (≈0.635 mm) is generally used, but in the present embodiment, the guide wire is used. As 4, it is assumed that a wire having a diameter of 0.025 inch is used.

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

The proximal end 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. A groove is formed on the side wall of the release handle 31 so as to penetrate inward and outward in the direction along the central axis thereof. In this groove, the foot portion of the release lever 32 having the head portion located on the outside of the release handle 31 and the foot portion erected in the central portion of the head portion is arranged so as to penetrate through the groove.

The tip (lower end) of the foot of the release lever 32 is fixed to the proximal end of the outer sheath 22 located inside the release handle 31, and by moving the release lever 32 along the groove. The outer sheath 22 can be slid toward 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 of the inner sheath 21 inserted into the outer sheath 22 passes through the release handle 31 and through the through hole of the proximal end side lid member of the release handle 31, the proximal end of which is the release handle. It is located outside 31. The inner sheath 21 is fixed to the proximal end side lid member (release handle 31) at the portion of the through hole. Further, the release handle 31 is provided with an injection port 33, and by connecting a syringe to the injection port 33 to feed physiological saline or the like, an outer is provided through the lumens of the injection port 33 and the release handle 31. Physiological saline or the like can be injected into the lumen of the sheath 22 (outside the inner sheath 21).

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

A tip tip 10 is attached to the distal end of the inner sheath 21. The tip tip 10 reduces irritation to the internal lumen when the distal end of the inner sheath 21 (catheter 2) abuts against the peripheral wall of the internal lumen, and further reduces the insertion resistance of the catheter 2. It serves to facilitate insertion into the body.

As shown in FIG. 2A, the tip tip 10 has a first member 100 connected to the distal end of the inner sheath 21 and a second member fixed so as to project axially from the distal end surface of the first member 100. It has 200 and is configured by connecting each member 100 and 200.

The ratio L1 / L of the total length L1 in the axial direction of the first member 100 and the total length L of the tip 10 is preferably 0.65 to 0.95. The ratio of the total length L2 in the axial direction of the second member 200 to 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 the members 100 and 200 in the axial direction is formed. As shown in FIG. 2A, inside the tubular inner space 160, the distal end of the inner sheath 21 expands the inner wall of the tubular inner space 160 and is near the axial center of the first member 100. Will be inserted. The guide wire 4 (not shown) that penetrates the lumen of the inner sheath 21 penetrates the inside of the tubular inner space 160 and protrudes from the opening at the distal end of the second member 200. The inner diameter of the tubular 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 side tapered portion 120, a large diameter portion 130, and a distal side tapered portion 140. The small diameter portion 110 is a portion on the proximal end side of the tip 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 tapers toward the proximal side is formed at the proximal end of the tapered portion 110.

The proximal side tapered portion 120 is arranged 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 located) to the distal side (the side where the second member 200 is located). It is a tapered surface portion that is inclined so that the outer diameter becomes large. In the present embodiment, the proximal side tapered portion 120 is formed so that the tapered surface is gently inclined.

The large diameter portion 130 is arranged on the distal side of the proximal side tapered 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 side tapered portion 120. It is the thickest part of the tip 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 tapered portion 140 is a tapered surface portion that is arranged on the distal side of the large diameter portion 130 and is inclined so that the outer diameter gradually decreases from the proximal side to the distal side. In the present embodiment, the tapered surface of the distal tapered portion 140 is composed of a first tapered surface 143 on the proximal side and a second tapered surface 144 on the distal side, depending on the inclination angle thereof. The tip of the catheter 2 is smoothly inserted into the lumen of the body and pushed forward by the action of the outer peripheral surface of the distal tapered portion 140 composed of the tapered surfaces 143 and 144. 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 tapered portion 140, a distal end face 142 formed of a plane perpendicular to the axial direction of the tip tip 10 is formed. The distal end surface 142 is a joint surface where the distal end of the first member 100 joins the second member 200.

On the distal side of the distal tapered portion 140, an anchor convex portion 141 protruding inward in the radial direction is formed. The anchor convex portion 141 can be engaged with the second member 200 (more specifically, the anchor concave portion 221 described later).

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

The second member 200 has a protrusion 210 and a proximal end 220. The protrusion 210 is a portion that protrudes in the axial direction from the distal end surface of the first member 100. The thickness of the distal end of the protrusion 210 is determined to such an extent that the tip 10 does not bend when the tip 10 presses the lumen of the body, and is preferably 0.1 to 0.3 mm. The L21 / L2 of the axial length L21 of the protrusion 210 and the axial total length L2 of the second member 200 is preferably 0.2 to 0.7. When inserting the catheter 2 into the internal lumen, the larger the value of L21 / L2 is, the better from the viewpoint of ensuring the piercing property of the tip tip 10, and from the viewpoint of reducing the irritation to the internal lumen, L21 / L2. The smaller the value of, the better.

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

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

An anchor recess 221 recessed inward in the radial direction is formed on the distal side of the proximal end 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 recess 221 is substantially the same as the axial length of the anchor convex portion 141, and the axial length L23 of the anchor recess 221 and the axial overall length L2 of the second member 200 The ratio L23 / L2 is preferably 0.2 to 0.4.

The base end portion 220 is fitted and inserted into the fitting and inserting tubular portion 170, and the fitting portion is joined (connected) by an adhesive or by fusion. At that time, since the anchor convex portion 141 engages with the anchor concave portion 221 to firmly connect the first member 100 and the second member 200, one of the first member 100 and the second member 200 is the other. It is possible to prevent it from coming out of.

In this embodiment, the second member 200 is made 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), preferably 60 to 80.

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

Lubricating treatment is applied to the entire outer peripheral surface of the tip tip 10. As a result, the outer peripheral surface of the tip tip 10 is formed so as to be slippery as a whole including the portion of the large diameter portion 130, which facilitates the insertion of the catheter 2. As an example of the lubricity treatment applied to the tip 10, a fluororesin coating, a silicone oil coating, a hydrogel coating, or the like can be used.

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. Further, the first member 100 and the second member 200 can be molded separately and bonded to each other by adhesion, welding or the like.

Next, a procedure for placing a stent using the stent delivery device of the present embodiment will be described with reference to FIGS. 3 to 9. For example, when a stent is placed in the abdominal cavity so as to bypass the stomach and the intrahepatic bile duct, as shown in FIG. 3, a puncture needle 73 extends from the stomach wall 71 to the bile duct wall 72 via the abdominal cavity 75. It punctures and forms a puncture hole 74 in both the stomach and the intrahepatic bile duct. Then, 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. In FIGS. 3 to 9, the endoscope is shown by a two-dot chain line.

Next, after expanding the puncture hole 74 with 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 toward the distal end. That is, as shown in FIG. 5, the stent 5 arranged in the stent arrangement portion of the inner sheath 21 is held inside the distal end portion of the outer sheath 22 in a reduced diameter state, and is distal to the catheter 2. The end portion (protruding portion 210 of the tip tip 10) is inserted into the puncture hole 74 on the stomach wall 71 side. Since the outer diameter of the protruding portion 210 of the tip tip 10 is sufficiently small and hard, the tip tip 10 has a high puncture property and can be easily inserted into the puncture hole 74 on the stomach wall 71 side.

Then, as shown in FIG. 6, when the catheter 2 (inner sheath 21 and outer sheath 22) is inserted so that the tip 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 stomach wall 71 side is gradually expanded by the distal taper portion 140 of the tip tip 10, and the puncture hole 74 on the stomach wall 71 side can be inserted into the distal end portion of the catheter 2 by the tip tip 10. Is extended to. After that, the catheter 2 is further inserted, and the distal end portion of the catheter 2 (the protruding portion 210 of the tip 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 tip tip 10 is sufficiently small and hard, the tip tip 10 has high puncture property, and the puncture hole on the bile duct wall 72 side is similar to the case of the puncture hole 74 on the stomach wall 71 side. It can be easily inserted into 74.

When the catheter 2 is further inserted, 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 gradually expanded by the tip tip 10 of the catheter 2. The distal end is dilated to the extent that it can be inserted. Catheter 2 is further inserted and the catheter 2 is inserted with the distal end of the stent 5 located inside the bile duct wall 72 and the proximal end of the stent 5 inside the stomach wall 71, as shown in FIG. To stop.

After that, in the operation unit 3, the release lever 32 is moved toward 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, the stent 5 is gradually exposed and expanded in diameter from its distal end, and by moving the release lever 32 to the proximal end of the groove, as shown in FIG. In addition, the stent 5 is exposed and expanded in diameter as a whole. Then, the catheter 2 and the tip tip 10 are passed through the inside of the enlarged stent 5 and pulled out to complete the placement of the stent 5.

In the catheter tip 10 according to the present embodiment, the second member 200 made of a material harder than the material of the first member 100 is fixed so as to protrude axially from the distal end surface of the first member 100. .. Therefore, the distal end of the catheter tip 10 has a high piercing property (pushing property), and smooth insertion is possible when the distal end of the catheter 2 is inserted into the puncture hole 74. On the other hand, a 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 surface on the proximal side of the tip tip 10 for a catheter has appropriate flexibility, and when the catheter 2 is inserted into the lumen of the body, irritation to the lumen of the body can be reduced.

In addition, in the catheter tip 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 internal lumen portion is increased by the amount of this curved surface, and it is possible to press the internal lumen portion with a high pressing force on this curved surface. Will be. Therefore, the piercing property of the tip tip 10 for a catheter can be further enhanced.

The tip 10A of the present embodiment shown in the second embodiment has the same configuration and operation and effect as those of the first embodiment described above except for the points shown below, and the description of common parts is omitted. In the drawings, common members are designated by common member codes. As shown in FIG. 2B, the tip tip 10A has a first member 100A and a second member 200A.

The first member 100A is the same as the first member 100 in the first embodiment except that it has a distal tapered portion 140A instead of the distal tapered portion 140. More specifically, the distal tapered portion 140 has an anchor convex portion 141A. The second tapered surface 144A is formed so 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 so that its axial length is shorter than the axial length of the anchor convex portion 141 in the first embodiment. The 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 tapered portion 140A becomes thicker than the distal end portion of the distal tapered portion 140.

The second member 200A is the same as the second member 200 in the first embodiment except that the protruding portion 210A is provided in place of the protruding portion 210 and the proximal end portion 220A is provided in place of the proximal end portion 220.

More specifically, as shown in FIG. 2B, the protrusion 210A has an axial length longer than the axial length of the protrusion 210 on the proximal side, and its outer circumference is from a plane parallel to the axial direction. It is formed so as to have a tubular shape. Further, the curved surface 211A is formed so that the radius of curvature thereof is larger than the radius of curvature of the curved surface 211.

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

Also 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 becomes thicker, it is less likely that the resin constituting the first member 100 will easily flow into the mold when the tip tip 10 is manufactured. , The moldability of the first member 100 can be improved.

Third Embodiment The tip tip 10B of the present embodiment shown in FIG. 2C has the same configuration and operation and effect as those of the second embodiment described above except for the points shown below, and the description of common parts is omitted. In the drawings, common members are designated by common member codes. As shown in FIG. 2C, the tip tip 10B has 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 base end portion 220B is provided in place of the base end portion 220A. More specifically, the proximal end 220B has an axial length longer than the axial length of the proximal end 220 in the second embodiment, and the proximal end has an anchor protrusion. The 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, the 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 the large diameter portion 130B instead of the large diameter portion 130, and the first member 100A in the second embodiment except that the first member 100B has the distal side tapered portion 140B instead of the distal side tapered portion 140. Is similar to. More specifically, the distal tapered portion 140B is formed so that the inset tubular portion 170B also extends to the proximal side thereof.

The large diameter portion 130B has an anchor recess 131B. The anchor recess 131B has a concave shape recessed outward in the radial direction so as to be able to engage with the anchor convex portion 222B 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.

Also 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 the anchor concave portion 131B in addition to the anchor convex portion 141A, and the second member 200B is formed with the anchor convex portion 222B in addition to the anchor concave portion 221A. Has been done. 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. It is possible to reliably prevent one of the first member 100B and the second member 200B from coming off from the other.

Fourth Embodiment The tip tip 10C of the present embodiment shown in FIG. 2D has the same configuration and operation and effect as those of the first embodiment described above except for the points shown below, and the description of common parts is omitted. In the drawings, common members are designated by common member codes. As shown in FIG. 2D, the tip 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 protrusion 210C is replaced with the protrusion 210 and the base end 220C is replaced with the base 220.

The protrusion 210C is formed so that its axial length is longer distal to 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 protrusion 210C. The intermediate tapered surface 212C is a tapered surface inclined so that the outer diameter gradually decreases from the proximal side to the distal side. The inclination angle of the intermediate tapered surface 212C is substantially equal to the inclination angle of the distal tapered portion 140C of the first member 100C. The portion of the protrusion 210C on which the intermediate tapered surface 212C is formed is formed so that its axial length is substantially equal to the axial length of the portion on which the intermediate tapered surface 212C is not formed. There is.

By providing the intermediate tapered surface 212C on the second member 200C, it is possible to smoothly connect the outer peripheral surface of the second member 200C to the outer peripheral surface of the first member 100C at a relatively gentle inclination angle. As a result, the tip of the catheter (protruding portion 210C) is smoothly inserted into the lumen of the body 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 221C has a concave shape recessed inward in the radial direction so as to be able to engage with the first member 100C (more specifically, the anchor convex portion 141C described later). The anchor recess 221C is formed so that the wall surface of the recess is vertical, unlike the anchor recess 221A shown in FIG. 2C, for example.

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, the anchor concave portion 145C described later). The anchor convex portion 222C is formed so that the wall surface of the convex portion is vertical, unlike the anchor convex portion 222B shown in FIG. 2C, for example.

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

The first tapered surface 143C is formed so that its axial length is distal to 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 distal side to the boundary with the second tapered surface 144, whereas the first tapered surface 143C shown in FIG. 2D is distal. It extends toward the side to the boundary portion of the second member 200C with the intermediate tapered surface 212C.

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

The anchor recess 145C has a concave shape recessed outward in the radial direction so as to be able to engage with the anchor protrusion 222C of the second member 200C. The anchor recess 145C is formed so that the wall surface of the recess is vertical, unlike the anchor recess 131B shown in FIG. 2C, for example.

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

Also in this embodiment, the same effect as that of the first embodiment can be obtained. In addition, in the present embodiment, 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, so that the first member 100C and the second member 200C are firmly connected. Therefore, it is possible to reliably prevent one of the first member 100C and the second member 200C from coming off from the other.

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 tip 10 is not limited to the example shown in FIG. 2A. A fork shape may be provided by providing an extending notch.

The inclination angles of the first tapered surface 143 and the second tapered surface 144 formed on the outer periphery of the distal tapered portion 140 may be appropriately changed. Further, the inclination angle of the tapered surface formed on the outer periphery of the proximal side tapered portion 120 may be appropriately changed.

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

In the above embodiment, three or more pairs of the anchor convex portion and the anchor concave portion may be formed. In this case, the first member 100 and the second member 200 are more firmly connected, and one of the first member 100 and the second member 200 can be effectively prevented from coming off from the other.

Hereinafter, the present invention will be described in more detail with reference to 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 molded on the first member 100 (total length L1 = 10 mm) of the tip tip 10. , A polyurethane resin (trade name: Tecoflex EG72D-B40, manufactured by Lubrizol) having a shore D hardness (JIS K 6253) of 67 is formed on the second member 200 (total length L2 = 3.4 mm). The first member 100 and the second member 200 were welded to prepare a sample of the tip tip 10 having a total length (L) of 11 mm and an axial length (L21) of the protruding portion 210 of 1 mm.

Comparative Example The total length (L2) of the second member 200 is 2.4 mm, and the protrusion 210 does not protrude in the axial direction from the distal end of the first member 100 (so that L21 = 0 mm). A sample similar to that of the example was prepared except that it was fixed to the inside of the member 100.

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

This load test was performed as follows. That is, first, each sample was lowered in the vertical direction, and the tip surface (curved portion 211) of the protruding portion 210 of those samples was pressed against the vinyl chloride sheet. Then, during that time, 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 an example as a solid line and a comparative example as a dotted line.

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

1 ... Stent delivery device 2 ... Catheter 21 ... Inner sheath 21a ... Opening 22 ... Outer sheath 25 ... Fixing ring 3 ... Operation unit 31 ... Release handle 32 ... Release lever 33 ... Injection port 4 ... Guide wire 5 ... Stent 10,10A, 10B, 10C ... Tip tip 100, 100A, 100B, 100C ... First member 110 ... Small diameter part 111 ... Curved surface 120, 120C ... Proximal side tapered part 121C ... Notch 130, 130B ... Large diameter part 140, 140A, 140B, 140C ... Distal tapered portion 141, 141A, 141C, 222B, 222C ... Anchor convex portion 142, 142A ... Distal end surface 143, 143C ... First tapered surface 144, 144A ... Second tapered surface 160 ... Inside the tubular shape Empty part 170, 170B ... Fitting tubular part 171 ... Proximal side tubular area 172 ... Intermediate tubular area 173 ... Distal side tubular area 200, 200A, 200B, 200C ... Second member 210, 210A, 210C ... Protruding portion 211,211A ... Curved surface 212C ... Intermediate tapered surface 220, 220A, 220B, 220C ... Base end portion 145C, 221,221A, 131B, 221C ... Anchor recess 71 ... Stomach wall 72 ... Biliary canal wall 73 ... Piercing needle 74 ... Hole 75 ... Peritoneal

Claims (4)

The first member connected to the distal end of the catheter and
It has a second member, which is fixed so as to protrude in the axial direction 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 .
Proximal to the outer peripheral surface on the proximal side of the portion where the taper on the distal side of the protrusion, which is a portion protruding in the axial direction from the distal end surface of the first member of the second member, is not formed. An intermediate tapered surface is formed that is inclined so that the outer diameter becomes smaller from the side to the distal side.
On the outer peripheral surface of the first member on the distal side, a distal tapered portion inclined so that the outer diameter becomes smaller from the proximal side to the distal side is formed.
A tip for a catheter, characterized in that the inclination angle of the intermediate tapered surface is substantially equal to the inclination angle of the distal tapered portion . The tip for a catheter according to claim 1, wherein the distal end portion of the second member has a tapered curved surface. The tip for a catheter according to claim 1 or 2, wherein the joint 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 to which the tip for a catheter according to any one of claims 1 to 3 is connected to a distal end.

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