Tube stent set

Abstract

To provide a tube stent set from which an inner catheter is easy to extract.SOLUTION: A tube stent set 1 comprises: a tube stent 2 with a bending part 6; and an inner catheter 3 disposed in the tube stent 2. The inner catheter 3 is pressed onto a radially-outside inner wall 2b of the bending part 6.SELECTED DRAWING: Figure 3

Description

Technical Field

[0001] The present disclosure relates to a tube stent set.

Background Art

[0002] A procedure is performed to place a tube stent at a site in a body lumen that is stenosed or occluded (hereinafter referred to as a stenosis / occlusion site). When placing a tube stent at a stenosis / occlusion site, a tube stent set including a tube stent and an inner catheter disposed within the tube stent is used. (See Patent Document 1)

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] A tube stent having a curved portion, such as a curve type or a pigtail type, is known. Here, when using a tube stent having a curved portion, when removing the inner catheter from the tube stent, a large frictional resistance is likely to occur due to contact between the curved portion of the tube stent and the inner catheter. As a result, it may be difficult to remove the inner catheter.

[0005] The present disclosure has been made in view of the above circumstances, and an object thereof is to provide a tube stent set that enables easy removal of the inner catheter.

Means for Solving the Problems

[0006] The tube stent set of the present disclosure includes a tube stent having a curved portion and an inner catheter disposed within the tube stent. The inner catheter is pressed against the inner wall on the radially outer side of the curved portion.

[0007] Any combination of the above components, as well as those obtained by converting the expressions of the present disclosure among methods, apparatuses, systems, etc., are also valid as one aspect of the present disclosure.

Advantages of the Invention

[0008] In the tube stent set of the present disclosure, the inner catheter can be easily removed.

Brief Description of the Drawings

[0009]

Figure 1

Figure 2

Figure 3

Modes for Carrying Out the Invention

[0010] Hereinafter, the present disclosure will be described with reference to the drawings based on preferred embodiments. The embodiments are illustrative rather than limiting the present disclosure, and not all features and combinations thereof described in the embodiments are necessarily essential to the present disclosure. The same or equivalent components, members, and processes shown in each drawing are denoted by the same reference numerals, and repeated explanations are omitted as appropriate. In addition, the scales and shapes of the respective parts shown in each figure are set for convenience in order to facilitate the explanation, and are not to be construed in a limited manner unless otherwise specified. Further, when terms such as "first", "second", etc. are used in this specification or claims, unless otherwise specified, these terms do not represent any order or importance, but are for distinguishing one configuration from another. In addition, in each drawing, some members that are not important in explaining the embodiments are omitted from the display.

[0011] FIG. 1 is a side view schematically showing an example of the tube stent set 1 of the present disclosure. As shown in FIG. 1, the tube stent set 1 of the present disclosure includes a tube stent 2 and an inner catheter 3.

[0012] The tube stent 2 is a medical instrument for treating various diseases caused by stenosis or occlusion of a living body lumen. For example, examples of the living body lumen include the bile duct or biliary tract, etc., and examples of diseases occurring in the bile duct or biliary tract include jaundice, biliary tract cancer, biliary tract obstruction, etc. However, the uses of the tube stent 2 are not limited to these.

[0013] The tube stent 2 may have any shape as long as it can open the living body lumen. As an example, the tube stent 2 has a long cylindrical shape having a first lumen 2a penetrating from the tip to the base end. The first lumen 2a serves to open the living body lumen.

[0014] FIG. 2 is a cross-sectional view schematically showing an example of a main part in the tube stent set 1 of the present disclosure. As shown in FIG. 2, the tube stent 2 may include an inner layer tube 4 and an outer layer tube 5. The inner layer tube 4 is a member that constitutes the inner wall 2b (inner surface) of the first lumen 2a of the tube stent 2. On the other hand, the outer layer tube 5 is a member that constitutes the outer wall 2c (outer surface) of the tube stent 2. And the inner wall 2b of the inner layer tube 4 may have lower friction than the outer wall 2c of the outer layer tube 5. The lower friction here means that the static friction coefficient of the inner wall 2b is lower than that of the outer wall 2c. If such a configuration is satisfied, the frictional resistance when removing the inner catheter 3 from the tube stent 2 can be reduced, and the possibility of displacement occurring when the tube stent 2 is placed can be lowered. The static friction coefficients of the inner wall 2b and the outer wall 2c may be measured in accordance with JIS K 7125. In this case, as the mating material in JIS K 7125, the material constituting the inner catheter 3 is used.

[0015] The static friction coefficients of the inner wall 2b and the outer wall 2c can be set to arbitrary values by appropriately selecting the materials constituting the inner layer tube 4 and the outer layer tube 5. The inner layer tube 4 may be made of, for example, a low-friction material. The low-friction material is, for example, a resin such as polytetrafluoroethylene (PTFE) or perfluoroalkoxy fluororesin (PFA). The outer layer tube 5 may be made of, for example, a high-friction material. The high-friction material is, for example, a resin such as polyurethane. The static friction coefficient of the inner wall 2b may be 1 / 5 or less of the static friction coefficient of the outer wall 2c.

[0016] The inner layer tube 4 and the outer layer tube 5 do not necessarily have to be in direct contact. For example, other members may be interposed between the inner layer tube 4 and the outer layer tube 5.

[0017] The tube stent 2 has a curved portion 6 (see FIG. 1). The curved portion 6 is a portion that is curved in a curved shape (or arcuate shape), that is, a portion that is curved substantially in a curve. In FIG. 1, a tube stent 2 having arcuate curved portions 6 at two locations on the distal end side and the proximal end side is illustrated. The tube stent 2 having such a shape is also called a pigtail type. When the tube stent 2 is viewed in the paper surface direction of FIG. 1, a part of the tube stent 2 overlaps. Therefore, the tube stent 2 has a three-dimensional shape rather than a shape that extends two-dimensionally (in a plane).

[0018] The inner catheter 3 is a medical instrument for transporting the tube stent 2 to a target position in a body lumen. As an example, the shape of the inner catheter 3 is a long cylindrical shape having a second lumen 3a that penetrates from the distal end to the proximal end. A medical instrument such as a guide wire can be inserted into the second lumen 3a.

[0019] In the tube stent set 1 of the present disclosure, the inner catheter 3 is inserted and disposed in the first lumen 2a of the tube stent 2.

[0020] FIG. 3 is a cross-sectional view schematically showing another example of a main part in the tube stent set 1 of the present disclosure. More specifically, FIG. 3 is a cross-sectional view along the central axis of the tube stent 2. As shown in FIG. 3, the inner catheter 3 is pressed against the inner wall 2b on the radially outer side of the curved portion 6 of the tube stent 2. FIG. 3 shows an example in which a part of the inner catheter 3 is pressed against the inner wall 2b on the radially outer side of the curved portion 6. Note that the present invention is not limited to this, and all of the inner catheter 3 (the entire section passing through the curved portion 6) may be pressed against the inner wall 2b on the radially outer side of the curved portion 6. Here, the radial direction refers to the radial direction centered on the central axis of the first lumen 2a. And the radially outer side refers to the side that protrudes convexly from the curved portion 6.

[0021] By satisfying such a configuration, in the curved portion 6 of the tube stent 2, the inner catheter 3 is always in a state of receiving a resistance force from the radially outer inner wall 2b. When the inner catheter 3 is removed from the tube stent 2, due to the loss of this resistance force, the inner catheter 3 tries to return to its initial shape by its self-restoring force. The initial shape is, for example, a linear shape, and the linear shape here means that the inner catheter 3 extends linearly as a whole. And the self-restoring force of this inner catheter 3 serves as an assisting force during removal. Therefore, the tube stent set 1 of the present disclosure facilitates the removal of the inner catheter 3.

[0022] The inner catheter 3 may be pressed against the radially outer inner wall 2b of the curved portion 6 so as to bring the curved portion 6 closer to a linear shape. Here, being pressed against so as to bring the curved portion 6 closer to a linear shape represents the following state. Compare the first curvature radius of the curved portion 6 in the state where the inner catheter 3 is disposed in the tube stent 2 with the second curvature radius of the curved portion 6 in the state where the inner catheter 3 is not disposed in the tube stent 2. The curvature radius is the radius of the arc constituting the radially outer outer wall 2c of the curved portion 6. And if the second curvature radius is larger than the first curvature radius, it can be said that it is pressed against so as to bring the curved portion 6 closer to a linear shape. Whether the second curvature radius is larger than the first curvature radius can be determined by splitting the tube stent 2 along the central axis with as little external force (external force deforming the inner catheter 3) as possible in the state where the inner catheter 3 is disposed in the tube stent 2. When the tube stent 2 is split along the central axis, if the curvature radius of the tube stent 2 becomes larger than before, it can be estimated that the tube stent 2 was trying to expand within the inner catheter 3. Therefore, in this case, it can be seen that the second curvature radius is larger than the first curvature radius. If such a configuration is satisfied, in the curved portion 6 of the tube stent 2, the inner catheter 3 is in a state of receiving a large resistance force from the inner wall 2b. Therefore, the removal of the inner catheter 3 becomes easier.

[0023] The inner catheter 3 may be separated from at least a part of the inner wall 2b on the radially inner side of the curved portion 6. The radially inner side refers to the concave side of the curved portion 6. If such a configuration is satisfied, the inner catheter 3 is not in contact with the inner wall 2b on the radially inner side of the curved portion 6. Therefore, when the inner catheter 3 is removed, the frictional resistance between the inner wall 2b on the radially inner side of the curved portion 6 and the inner catheter 3 is reduced, and the removal of the inner catheter 3 becomes easier.

[0024] The inner catheter 3 may be made of a material having, for example, flexibility and biocompatibility. Materials having flexibility and biocompatibility are, for example, resins such as polyethylene terephthalate (PET), polyether block amide copolymer resin (PEBAX (registered trademark)), or polyolefin-based resin.

[0025] The tube stent set 1 of the present disclosure may include an outer catheter. The shape of the outer catheter may be a long cylindrical shape having a third lumen that penetrates from the distal end to the proximal end, similar to the inner catheter 3. And the inner catheter 3 is inserted into the third lumen of the outer catheter so as to be able to advance and retreat, leaving the portion disposed in the tube stent 2.

[0026] In addition, the tube stent set 1 of the present disclosure may include a handle that is attached to the proximal end side of the outer catheter and supports the outer catheter. The handle is a member that is gripped by the operator.

[0027] The handle may be provided with an advance / retreat operation portion such as a slide knob. The advance / retreat operation portion is connected to the proximal end side of the inner catheter 3 and is a member that can operate the advance and retreat of the inner catheter 3.

[0028] An example of a manufacturing method of the tube stent set 1 of the present disclosure will be described.

[0029] First, prepare a tube stent 2 having a curved portion 6 and a straight inner catheter 3. Here, the straight shape means that the inner catheter 3 extends linearly as a whole. That is, prepare an inner catheter 3 that has not been intentionally deformed. Note that the tube stent 2 and the inner catheter 3 may be manufactured by a known method such as extrusion molding of an arbitrary resin material.

[0030] Next, insert and place the inner catheter 3 into the first lumen 2a of the tube stent 2. Then, heat and sterilize both the tube stent 2 and the inner catheter 3. In this way, by using the straight inner catheter 3, the tube stent set 1 of the present disclosure is obtained in which the inner catheter 3 is pressed against the inner wall 2b on the radially outer side of the curved portion 6 of the tube stent 2 by the elastic force with which the inner catheter 3 tries to return to its original shape. On the other hand, when an inner catheter 3 having a curved portion instead of a straight shape is used, the inner catheter 3 is not pressed against the inner wall 2b on the radially outer side of the curved portion 6 of the tube stent 2, but is merely in contact. Therefore, the tube stent set 1 of the present disclosure cannot be obtained.

[0031] The embodiments of the present disclosure have been described in detail above. The above-described embodiments are merely specific examples for implementing the present disclosure. The content of the embodiments does not limit the technical scope of the present disclosure, and many design changes such as component changes, additions, deletions, etc. are possible without departing from the idea of the present disclosure defined in the claims. The new embodiments with design changes have the combined effects of the combined embodiments and the modifications. Any combination of the components included in each embodiment is also valid as an aspect of the present disclosure. The hatching attached to the cross-section of the drawing does not limit the material of the object to which the hatching is attached.

[0032] The embodiments may be specified by the items described below. [Item 1] A tube stent (2) having a curved portion (6), and an inner catheter (3) disposed within the tube stent (2), wherein the inner catheter (3) is pressed against an inner wall (2b) on the radially outer side of the curved portion (6), a tube stent set (1). [Item 2] The inner catheter (3) is pressed against an inner wall (2b) on the radially outer side of the curved portion (6) so as to bring the curved portion (6) closer to a linear shape, the tube stent set (1) according to claim 1. [Item 3] The inner catheter (3) is separated from at least a part of an inner wall (2b) on the radially inner side of the curved portion (6), the tube stent set (1) according to claim 1. [Item 4] The tube stent (2) includes an inner layer tube (4) and an outer layer tube (5), and an inner wall (2b) of the inner layer tube (2) has lower friction than an outer wall (2c) of the outer layer tube (5), the tube stent set (1) according to claim 1. [Item 5] Insert a straight inner catheter (3) into a tube stent (2) having a curved portion (6), After disposing the inner catheter (3) within the tube stent (2), heat and sterilize, a method for manufacturing the tube stent set (1) according to claim 1.

Explanation of Reference Numerals

[0033] 1: Tube stent set 2: Tube stent 2a: First lumen 2b: Inner wall 2c: Outer wall 3: Inner catheter 3a: Second lumen 4: Inner layer tube 5: Outer layer tube 6: Curved portion

Claims

1. A tube stent having a curved portion, and an inner catheter having a lumen through which a medical instrument can be inserted and disposed within the tube stent, The inner catheter is pressed against the inner wall on the outer radial side of the curved portion, a tube stent set.

2. The inner catheter is pressed against the inner wall on the outer radial side of the curved portion so as to approximate the curved portion to a linear shape, the tube stent set according to claim 1.

3. The inner catheter is separated from at least a part of the inner wall on the inner radial side of the curved portion, the tube stent set according to claim 1.

4. The tube stent includes an inner layer tube and an outer layer tube, and the inner wall of the inner layer tube has lower friction than the outer wall of the outer layer tube, the tube stent set according to claim 1.

5. Insert a straight inner catheter having a lumen through which a medical instrument can be inserted into a tube stent having a curved portion, Dispose the inner catheter within the tube stent, and heat and sterilize the inner catheter while it is pressed against the inner wall on the outer radial side of the curved portion, a method for manufacturing the tube stent set according to claim 1.

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