WO2025205290A1 - Medical instrument - Google Patents

Abstract

Provided is a medical instrument including an in vivo indwelling tube in which a tube stent placed inside a living body can be easily removed from inside the living body.　The medical instrument includes: an in vivo indwelling tube having a longitudinal direction and having a proximal end and a distal end; an outer cylindrical member having a longitudinal direction; an inner cylindrical member disposed at least in a lumen of the outer cylindrical member, having a longitudinal direction, and having a proximal end and a distal end; and a yarn body. The in vivo indwelling tube has a through-hole in a side wall of a proximal part of the in vivo indwelling tube. The outer cylindrical member has a through-hole in a side wall of a distal part of the outer cylindrical member. The yarn body is configured as a closed loop passing through the through-hole of the in vivo indwelling tube. A part of the proximal end part of the in vivo indwelling tube is disposed in the loop. The loop of the yarn body is passed through the through-hole of the outer cylindrical member. The inner cylindrical member is disposed in the loop.

Description

medical equipment

The present invention relates to a medical device including an in-vivo indwelling tube.

Body lumens, such as blood vessels or digestive tracts like the bile duct or pancreatic duct, can become narrowed or blocked for a variety of reasons. One known method for treating various diseases caused by narrowing or obstruction is to place a tubular stent at the narrowed or obstructed site, dilating the narrowed or obstructed site from the inside, and widening the body lumen. For example, when narrowing or obstruction occurs in the bile duct, a bile duct tube stent is delivered to the narrowed or obstructed site. The tube stent delivered to the narrowed or obstructed site remains in place, expanding the narrowed or obstructed site from the inside. Placement of the tube stent widens the inner diameter of the bile duct at the narrowed or obstructed site, thereby improving the narrowing or obstruction. This allows bile to be discharged from the bile duct to the duodenum, enabling the treatment of various diseases caused by narrowing or obstruction of the bile duct, such as biliary atresia, jaundice, and biliary tract cancer. A medical device with such a tube stent is described, for example, in Patent Document 1.

Patent Document 1 describes a stent kit comprising a tube stent having a stent arc portion, at least one end of which is formed of at least a portion of an arc, and an inner catheter having an inner arc portion formed with the same shape as the stent arc portion and inserted into the tube stent so that the inner arc portion and the stent arc portion are aligned. Patent Document 1 also discloses a connecting means in which a thread member having a knobby member is tied through a hole formed radially in a pusher catheter, the knobby member fits loosely into a locking hole in the stent, and the inner catheter is inserted into the pusher catheter and stent with the thread member extending beyond the locking hole as viewed from the pusher catheter.

Patent No. 5408682

When placing a tube stent at a stenosis or occlusion site, it is necessary to position the tube stent by pushing it distally or pulling it back proximally relative to the stenosis or occlusion site. For this reason, for example, in the above-mentioned Patent Document 1, a thread tied to the pusher catheter is used to connect the pusher catheter and the stent, allowing the stent to be pulled back proximally. After the stent is placed, the thread is removed from the body along with the pusher catheter.

However, if cancer cells or other diseased tissue, bile sludge, or stones enter the lumen of a tube stent placed in the body and cause the lumen to become blocked or narrowed, the tube stent must be removed from the body through an endoscope and replaced. However, it has been difficult to remove a tube stent from the body once it has been placed.

The present invention was made in light of the above-mentioned circumstances, and its purpose is to provide a medical device including an in-vivo tube that allows for easy removal of a tube stent placed in the body.

The present invention is as follows.
[1] A medical device comprising: an in-vivo tube having a longitudinal direction and a proximal end and a distal end; an outer tubular member having a longitudinal direction; an inner tubular member having a longitudinal direction and a proximal end and a distal end, the inner tubular member being disposed in at least the lumen of the outer tubular member; and a filament, wherein the in-vivo tube has a through-hole in a side wall of a proximal portion of the in-vivo tube; the outer tubular member has a through-hole in a side wall of a distal portion of the outer tubular member; the filament passes through the through-hole of the in-vivo tube and is configured as a closed ring, with a part of the proximal end of the in-vivo tube disposed within the ring; and the ring of the filament is passed through the through-hole of the outer tubular member, and the inner tubular member is disposed within the ring.
[2] The medical device according to [1], wherein the thread body has a catch portion.
[3] The medical device according to [1] or [2], which has a second thread body connected to the thread body.
[4] The medical device according to [3], wherein the second thread body has a catch portion.
[5] The medical device according to [2] or [4], wherein the catch portion is a portion of the thread body where frictional force is high, or a portion of the second thread body where frictional force is high.
[6] The medical device according to any one of [2], [4], and [5], wherein the hooking portion is configured as a closed loop.
[7] The medical device according to any one of [2] and [4] to [6], wherein the catch portion is a thickened portion of the thread body or a thickened portion of the second thread body.
[8] The medical device according to any one of [2] and [4] to [7], wherein the catch portion is disposed in a proximal portion of the thread body or in a proximal portion of the second thread body.
[9] The medical device according to any one of [1] to [8], wherein the inner tube member is disposed in the lumen of the outer tube member and the lumen of the indwelling tube, and is movable in the longitudinal direction of the indwelling tube.
[10] The medical device according to [9], wherein the distal end of the inner cylindrical member cannot move distally beyond the distal end of the indwelling tube.
[11] The medical device according to any one of [1] to [10], wherein the inner cylindrical member has an X-ray opaque marker at a distal portion of the inner cylindrical member.
[12] The medical device according to any one of [1] to [11], wherein the in-vivo indwelling tube has a drainage hole in the side wall of the in-vivo indwelling tube.
[13] The medical device according to any one of [1] to [12], wherein the indwelling tube has a locking flap on the outer surface of the proximal portion and/or the outer surface of the distal portion of the indwelling tube.
[14] The medical device according to any one of [1] to [13], wherein the in-vivo indwelling tube is a plastic tube stent to be placed in the bile duct or pancreatic duct.
[15] The medical device according to any one of [1] to [14], wherein the in-vivo indwelling tube has an arcuate portion that is curved in an arc shape in a plan view.
[16] The medical device according to any one of [1] to [15], wherein the inner cylindrical member has a tapered distal end portion thereof such that the outer diameter decreases toward the distal end.

The medical device of the present invention includes an in-vivo indwelling tube, which has a filament. As a result, the in-vivo indwelling tube and the filament are retained in the living body, and when removing the in-vivo indwelling tube from the living body, the in-vivo indwelling tube can be easily removed from the living body by pulling the filament proximally.

FIG. 1 is a cross-sectional view showing an embodiment of a medical device. FIG. 2 is a cross-sectional view showing another embodiment of the medical device. FIG. 3 is a cross-sectional view showing another embodiment of the medical device. 4 is a side view showing the proximal end of the in-vivo indwelling tube in the medical device shown in FIG. 1. FIG. FIG. 5 is a side view showing another example of the configuration of the proximal end portion of the in-vivo indwelling tube in the medical device shown in FIG. FIG. 6 is a side view showing another example of the configuration of the proximal end portion of the in-vivo indwelling tube in the medical device shown in FIG. FIG. 7 is a cross-sectional view showing another embodiment of the medical device. FIG. 8 is a cross-sectional view showing another embodiment of the medical device. FIG. 9 is a cross-sectional view showing another embodiment of the medical device. FIG. 10 is a cross-sectional view showing another embodiment of the medical device. FIG. 11 is a cross-sectional view showing another embodiment of the medical device. FIG. 12 is a cross-sectional view showing another embodiment of the medical device.

An embodiment of the medical device according to the present invention is a medical device comprising an in-vivo tube having a longitudinal direction and a proximal end and a distal end, an outer tubular member having a longitudinal direction, an inner tubular member having a longitudinal direction and a proximal end and a distal end, the inner tubular member being disposed within at least the lumen of the outer tubular member, and a filament, the in-vivo tube having a through-hole in the side wall of the proximal portion of the in-vivo tube, the outer tubular member having a through-hole in the side wall of the distal portion of the outer tubular member, the filament passing through the through-hole of the in-vivo tube and forming a closed ring, with a portion of the proximal end of the in-vivo tube disposed within the ring, and the ring of the filament passing through the through-hole of the outer tubular member, the inner tubular member being disposed within the ring.

The present invention will be described in more detail below based on the embodiments, but the present invention is not limited to the embodiments described below. Of course, modifications can be made to the present invention within the scope of the above and below-described intent, and all such modifications are within the technical scope of the present invention. For convenience, hatching and component symbols may be omitted in the drawings. In such cases, reference should be made to the specification or other drawings. The dimensions of the various components in the drawings may differ from the actual dimensions, as priority is given to aiding understanding of the features of the present invention.

In this specification, the proximal side refers to the direction toward the user in the longitudinal direction, and the distal side refers to the side opposite the proximal side, i.e., the direction toward the treatment target. Furthermore, when each component is divided into two equal parts longitudinally, the part of each component located on the distal side is referred to as the distal section, and the part of each component located on the proximal side is referred to as the proximal section. The distal end of each component is the end located most distally, and the proximal end of each component is the end located most proximal. The end of each component refers to the part including the end of each component and its surrounding area. In other words, the distal end of each component refers to the part including the distal end of each component and its surrounding area, and the proximal end of each component refers to the part including the proximal end of each component and its surrounding area.

Figure 1 is a cross-sectional view showing an embodiment of a medical device. As shown in Figure 1, the medical device 1 includes an in-vivo indwelling tube 10, an inner tubular member 20, an outer tubular member 50, and a filament 60. In Figure 1, the portion of the filament 60 that is on the front side of the page is shown by a dashed line to make it easier to understand the positional relationship between the filament 60 and the inner tubular member 20. In Figure 1, the right side of the figure is the proximal side, and the left side of the figure is the distal side. The same applies below.

The in-vivo tube 10 has a longitudinal direction and a proximal end 10a and a distal end 10b. The in-vivo tube 10 has a through-hole 18 in the side wall of the proximal portion of the in-vivo tube 10.

The outer tube member 50 has a longitudinal direction and has a through-hole 58 in the side wall of the distal portion of the outer tube member 50. The distal portion of the outer tube member 50 may be the region from the distal end 50b of the outer tube member 50 to a position 60 mm longitudinally proximal to the distal end 50b of the outer tube member 50.

The outer tube member 50 may be arranged proximal to the proximal end of the in-vivo tube 10, or as shown in Figure 1, may be arranged proximal to the proximal end 10a of the in-vivo tube 10. The proximal end of the in-vivo tube 10 may be up to a position 20 mm longitudinally away from the proximal end 10a of the in-vivo tube 10 toward the distal end 10b of the in-vivo tube 10. When the outer tube member 50 is arranged proximal to the proximal end of the in-vivo tube 10, at least a portion of the proximal end of the in-vivo tube 10 may be covered by at least a portion of the distal end of the outer tube member 50. When the outer tubular member 50 is disposed proximal to the proximal end of the indwelling tube 10, and at least a portion of the proximal end of the indwelling tube 10 is covered by at least a portion of the distal end of the outer tubular member 50, a step may be provided in the inner diameter at the distal end of the outer tubular member 50, and the proximal end 10a of the indwelling tube 10 may abut against the inner wall of the outer tubular member 50. The distal end of the outer tubular member 50 may be up to a position 20 mm away from the distal end 50b of the outer tubular member 50 toward the proximal end 50a of the outer tubular member 50 in the longitudinal direction.

The inner tube member 20 has a longitudinal direction and a proximal end 20a and a distal end 20b.

The proximal end 10a of the in-vivo indwelling tube 10 and the proximal end 20a of the inner cylindrical member 20 refer to the end on the user's side (the surgeon's side), while the distal end 10b of the in-vivo indwelling tube 10 and the distal end 20b of the inner cylindrical member 20 refer to the end on the opposite side of the proximal end (i.e., the end on the treatment target side).

The direction from the proximal end 10a to the distal end 10b of the in-vivo indwelling tube 10, and the direction from the proximal end 20a to the distal end 20b of the inner tube member 20, are referred to as the longitudinal direction.

The inner tube member 20 only needs to be movably disposed within the lumen of the outer tube member 50. In other words, the inner tube member 20 can be unfixed relative to the outer tube member 50, as long as it is movable.

The inner tubular member 20 only needs to be movably disposed within the lumen of the in-vivo indwelling tube 10. In other words, the inner tubular member 20 can be unfixed relative to the in-vivo indwelling tube 10, as long as it is movable.

The inner tube member 20 is disposed within at least the lumen of the outer tube member 50, and may also be disposed within the lumen of the in-vivo indwelling tube 10.

1, the thread body 60 passes through the through-hole 18 of the in-vivo tubing 10 and is configured as a closed ring, with a portion of the proximal end of the in-vivo tubing 10 disposed within the ring. A portion of the proximal end of the in-vivo tubing 10 proximal to the through-hole 18 of the in-vivo tubing 10 may also be disposed within the ring of the thread body 60. The thread body 60 shown in FIG. 1 is configured as a ring by connecting one end to the other end. The ring of the thread body 60 is passed through the through-hole 58 of the outer tubular member 50, with the inner tubular member 20 disposed within the ring. In this case, a portion 59 of the distal end of the outer tubular member 50 is not disposed within the ring of the thread body 60. By arranging the inner tubular member 20 so that it passes through the loop formed by the filament 60 and connecting the in-vivo tube 10 and the outer tubular member 50, force applied from the proximal side is easily transmitted to the in-vivo tube 10 through the outer tubular member 50, making it easier to push the in-vivo tube 10 distally and transport the in-vivo tube 10 to the affected area. Furthermore, even after the in-vivo tube 10 has been delivered to the affected area, the in-vivo tube 10 is pulled by the filament 60 by pulling the inner tubular member 20 and the outer tubular member 50 proximally, and the in-vivo tube 10 can be moved proximally, making it easier to position the in-vivo tube 10 when it is placed. Furthermore, by inserting the thread 60 into the through-hole 18 of the in-vivo tube 10 and inserting the loop of the thread 60 into the through-hole 58 of the outer tubular member 50, the in-vivo tube 10 and the outer tubular member 50 can be easily connected by the thread 60. Furthermore, by configuring the thread 60 as a closed ring and disposing the inner tubular member 20 inside the ring, if the inner tubular member 20 is pulled proximally to remove the inner tubular member 20 from the ring, and then further pulling the outer tubular member 50 proximally, the loop of the thread 60 is released to the outside of the outer tubular member 50 through the through-hole 58 of the outer tubular member 50, thereby easily releasing the connection between the in-vivo tube 10 and the outer tubular member 50. This makes it easier to place the in-vivo tube 10 in the affected area. Furthermore, by including the thread 60 in the in-vivo tube 10, the thread 60 is placed in the living body together with the in-vivo tube 10. Therefore, when removing the in-vivo indwelling tube 10 from the living body, the in-vivo indwelling tube 10 can be easily removed from the living body by pulling the filament 60 proximally.

Figure 2 is a cross-sectional view showing another embodiment of the medical device 1. The medical device 1 shown in Figure 2 and the medical device 1 shown in Figure 1 are the same except for the length of the thread 60. In the medical device 1 shown in Figure 1, the length of the thread 60 is configured to be as short as possible so as to be able to connect the in-vivo indwelling tube 10 and the outer tubular member 50, but the length of the thread 60 is not limited to this and may be longer, as shown in Figure 2. In this case, the thread 60 may extend in the direction of the proximal end 50a of the outer tubular member 50. Furthermore, while the thread 60 shown in Figure 1 forms a ring by connecting one end to the other, it may also form a ring by knotting one end of the thread 60 to the other end, as shown in Figure 2. In other words, the thread 60 may have a knot 60z.

3 is a cross-sectional view showing another embodiment of the medical device 1. The thread body 60 of the medical device 1 shown in FIG. 3 has a knot 60z formed therein. As shown in FIG. 3, the formation of the knot 60z in the thread body 60 allows the size of the loop of the thread body 60 to be adjusted. Reducing the size of the loop increases the friction between the inner tubular member 20 and the loop of the thread body 60, making it easier for the inner tubular member 20 to be caught on the loop of the thread body 60. As shown in FIG. 3, the thread body 60 does not need to have a loop formed on the side opposite the loop formed on the knot 60z of the thread body 60. When no loop is formed on the side opposite the loop formed on the knot 60z of the thread body 60 as shown in FIG. 3, the thread body 60 may have a hook portion. The presence of the hook portion makes it easier to pull the thread body 60, thereby facilitating removal of the in-vivo indwelling tube 10 from within the living body. The hook portion will be described later. The knot 60z of the thread body 60 may also be formed in the thread body 60 of the medical device 1 shown in Figure 2 above. This increases the frictional force between the inner tube member 20 and the ring of the thread body 60, making it easier for the inner tube member 20 to be caught on the ring of the thread body 60. Instead of providing the knot 60z, portions of the thread body 60 may be fused together, or portions of the thread body 60 may be connected together via an adhesive.

Figure 4 is a side view of the proximal end of the in-vivo tube 10 in the medical device 1 shown in Figure 1, as viewed from below. In Figure 4, the portion of the filament 60 on the back side of the page is shown by a dashed line to make it easier to understand the positional relationship between the in-vivo tube 10 and the filament 60. This is the same for Figures 5 and 6 below. As shown in Figure 4, there is one through hole 18 formed in the side wall of the in-vivo tube 10 in the medical device 1 shown in Figure 1, and the filament 60 is passed through the through hole 18 to form a loop.

5 and 6 are side views showing other configuration examples of the proximal end of the in-vivo tube 10 in the medical device 1 shown in FIG. 1. In the medical device 1 shown in FIGS. 5 and 6, two through holes 18a and 18b are formed in the side wall of the in-vivo tube 10. The number of through holes 18 in the in-vivo tube 10 may be one, as shown in FIG. 4, two, as shown in FIGS. 5 and 6, or three or more (not shown). The upper limit of the number of through holes 18 in the in-vivo tube 10 is not particularly limited, but may be, for example, five or fewer, or four or fewer. When multiple through holes 18 are formed, the arrangement of the through holes 18 is not particularly limited. For example, as shown in FIGS. 5 and 6, the through holes 18a and 18b may be arranged side by side in the circumferential direction of the in-vivo tube 10, or the through holes 18a and 18b may be arranged side by side in the longitudinal direction of the in-vivo tube 10. The method for connecting the filament 60 to the in-vivo indwelling tube 10 is not particularly limited; as shown in Figure 5, the loop of the filament 60 may be disposed within the lumen of the in-vivo indwelling tube 10, or as shown in Figure 6, the loop of the filament 60 may be disposed on the outside of the in-vivo indwelling tube 10.

The opening shape of the through-holes 18 of the in-vivo indwelling tube 10, when viewed from above, can be, for example, circular, elliptical, oval, oval, polygonal, or a combination of these. If the in-vivo indwelling tube 10 has two or more through-holes 18, the opening shapes of some of the through-holes may be different, or all of the through-holes may have the same opening shape; it is preferable that all of the through-holes have the same opening shape.

The opening area per through-hole 18 of the indwelling tube 10 may be, for example, 0.7 to 4.0 ^mm2 , 0.4 to 6.0 ^mm2 , or 0.1 to 8.0 ^mm2 in plan view of the indwelling tube 10.

The area in which the through-holes 18 of the in-vivo tube 10 are located may be, for example, within an area 1 to 9 mm, 2 to 7 mm, or 3 to 5 mm away from the proximal end 10a of the in-vivo tube 10 toward the distal end 10b when viewed from above.

When the filament 60 is stretched in the longitudinal direction of the in-vivo indwelling tube 10, the length of the filament 60, as viewed in plan of the in-vivo indwelling tube 10, is preferably 10 to 200 mm, more preferably 50 to 150 mm, and even more preferably 80 to 120 mm.

The diameter (wire diameter) of the filament 60 may be, for example, 0.05 mm to 0.8 mm, or 0.05 mm to 0.5 mm.

The thread body 60 may be a solid wire or a twisted wire.

The thread body 60 may be, for example, a suture. By using a suture as the thread body 60, it is possible to make it flexible while maintaining durability, and therefore the thread body 60 is less likely to damage the in-vivo indwelling tube 10 or the luminal wall of the in-vivo lumen.

The material constituting the thread body 60 is not particularly limited, and examples thereof include natural fibers, metals, and resins, with resins being preferred. Examples of natural fibers include cotton, linen, silk, and wool. Examples of metals include gold, platinum, and titanium. Examples of resins include polyamide-based resins such as nylon; polyether polyamide-based resins; polyimide-based resins; polyester-based resins such as polyethylene terephthalate (PET); polyurethane-based resins; polyolefin-based resins such as polyethylene and polypropylene; fluorine-based resins such as polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), and ethylene tetrafluoroethylene copolymer (ETFE); polyvinyl chloride-based resins; silicone-based resins; and natural rubber. These materials may be used alone or in combination. Among these, polyamide-based resins, polyester-based resins, polyurethane-based resins, polyolefin-based resins, and fluorine-based resins are particularly preferred.

Figure 7 is a cross-sectional view showing another embodiment of the medical device 1, with the inner tubular member 20 and outer tubular member 50 not shown. As shown in Figure 7, the medical device 1 may have an extension portion in which a second thread body 61 is connected as a separate body to the thread body 60. This allows the length of the thread body 60 to be extended by the second thread body 61 even if it is short, so that when the in-vivo indwelling tube 10 is placed in, for example, the bile duct, at least a portion of the second thread body 61 can be exposed to the duodenum. As a result, the in-vivo indwelling tube 10 can be easily removed from the living body.

As shown in Figure 7, the second thread body 61 may be knotted to the thread body 60 and connected at a knot 61z to form a closed loop. Alternatively, the second thread body 61 may pass through the loop of the thread body 60 and form a closed loop. In other words, the thread body 60 and the second thread body 61 may be connected in an unfixed manner (not shown).

The second thread body 61 may have one end connected to the thread body 60. For example, the second thread body 61 may be connected by tying one end of the second thread body 61 to the thread body 60, or may be fixed by adhesive, heat fusion, or the like (not shown). When one end of the second thread body 61 is connected to the thread body 60 but is not configured as a closed ring, the proximal end of the second thread body 61 may have a hook portion. The hook portion allows the surgeon to easily grasp and pull the second thread body 61, making it easier to remove the in vivo indwelling tube 10 from the living body.

The catch portion is preferably a high-friction portion of the thread body 60 or a high-friction portion of the second thread body 61. High frictional force facilitates catch, making it easier to pull out the implanted in-vivo tube 10. The portion with increased frictional force may be, for example, a portion where the material of the thread body 60 or the second thread body 61 has been changed to a high-friction material, or a portion where the surface roughness of the thread body 60 or the second thread body 61 has been increased, or a portion where the structure of the thread body 60 or the second thread body 61 has been changed to, for example, a twisted wire. The friction coefficient of the portion with increased frictional force is preferably, for example, 0.2 or greater. The friction coefficient may be measured, for example, using a friction and wear tester in accordance with JIS K7125. When the frictional force is increased by increasing the surface roughness, the arithmetic mean roughness (Ra) is preferably 12.5 or greater. The arithmetic mean roughness (Ra) can be measured, for example, using a laser microscope in accordance with JIS B0601.

Figure 8 is a cross-sectional view showing another embodiment of the medical device 1, with the inner tube member 20 and outer tube member 50 not shown. As shown in Figure 8, the medical device 1 has one end of a second thread body 61 tied to the thread body 60 and connected at a knot 61z, and the other end may have a closed loop 61a as a hook. The shape of the closed loop 61a is not particularly limited, but examples include a circle, an ellipse, an oval, an egg, a polygon, or a combination of these. Note that the second thread body 61 can be read as the thread body 60.

Figure 9 is a cross-sectional view showing another embodiment of the medical device 1, with the inner tube member 20 and outer tube member 50 not shown. As shown in Figure 9, the medical device 1 has one end of the second thread body 61 tied to the thread body 60 and connected at a knot 61z, and the other end may have a portion 61b (large diameter portion) where the diameter of the second thread body 61 is partially increased as a hook. The increased diameter portion 61b may have any thickness, and its shape is not particularly limited, and examples include a sphere, an elongated spheroid, and an oblate spheroid. Note that the second thread body 61 can be read as the thread body 60.

The thickened portion 61b can be formed, for example, by using a thread body 60 with a portion having an increased diameter as the second thread body 61, by forming a knot at the other end of the second thread body 61 to increase the diameter, by winding a third thread body around a portion of the second thread body 61 or tying the third thread body to increase the diameter, or by attaching resin, metal, or the like to the second thread body 61. The method for attaching resin to the second thread body 61 is not particularly limited, and a resin tube or resin film may be welded to the second thread body 61, or a resin tube or resin film may be adhered using an adhesive. The method for attaching metal to the second thread body 61 is also not particularly limited, and metal may be coiled around the second thread body 61. Note that the second thread body 61 can be read as thread body 60.

The location of the catch portion is not particularly limited, but it may be the proximal portion (particularly the proximal end) of the thread body 60 or the proximal portion (particularly the proximal end) of the second thread body 61. By locating the catch portion at the proximal end of the thread body 60 or the second thread body 61, it becomes easier to pull the in-vivo indwelling tube 10 proximally, making it easier to remove the in-vivo indwelling tube 10 from within the body.

When the second thread body 61 is connected to the thread body 60, the overall length of the thread body 60 and the second thread body 61 when stretched in the longitudinal direction of the in-vivo indwelling tube 10 is, for example, preferably 10 to 200 mm, more preferably 50 to 150 mm, and even more preferably 80 to 120 mm, in a plan view of the in-vivo indwelling tube 10.

The diameter (wire diameter) of the second filament body 61 may be, for example, 0.05 mm to 0.8 mm, or 0.05 mm to 0.5 mm.

The second filament body 61 may be a solid wire or a twisted wire.

The second filament body 61 may be, for example, a suture. By using a suture as the second filament body 61, it can be made flexible while maintaining durability, making it less likely that the second filament body 61 will damage the in-vivo indwelling tube 10 or the luminal wall of the in-vivo lumen.

The material constituting the second thread body 61 is not particularly limited, and examples include natural fibers, metals, and resins, with resins being preferred. The materials constituting the second thread body 61 can be the same as those exemplified as the materials constituting the thread body 60 above. The materials constituting the thread body 60 and the second thread body 61 may be the same or different. When the constituent materials are different, by making the rigidity of the second thread body 61 lower than the rigidity of the thread body 60, the second thread body 61 can be less likely to damage the in-vivo indwelling tube 10, the luminal wall of the in-vivo lumen, etc.

The diameter of the thread body 60 and the diameter of the second thread body 61 may be the same or different. If the diameters of the thread body 60 and the second thread body 61 are different, the burden on the patient can be reduced by making the diameter of the second thread body 61 smaller than the diameter of the thread body 60.

The color of the thread body 60 and the color of the second thread body 61 may be the same or different. By having the thread body 60 and the second thread body 61 be different colors, it becomes easier to distinguish between the thread body 60 and the second thread body 61, making it easier to remove the in-vivo indwelling tube 10 from within the living body.

When the inner tubular member 20 is disposed in the lumen of the outer tubular member 50 and the lumen of the indwelling tube 10, it is preferable that the inner tubular member 20 be movable in the longitudinal direction of the indwelling tube 10. When the inner tubular member 20 is disposed in the lumen of the outer tubular member 50 and the lumen of the indwelling tube 10 and is movable in the longitudinal direction of the indwelling tube 10, it is preferable that the distal end of the inner tubular member 20 cannot be moved distally beyond the distal end of the indwelling tube 10.

The inner tube member 20 may have an X-ray opaque marker at the distal portion of the inner tube member 20. By having an X-ray opaque marker, the position of the inner tube member 20 can be confirmed under X-ray fluoroscopy.

There is no particular limit to the number of radiopaque markers; it may be one, two or more, or three or more.

The shape of the radiopaque marker is not particularly limited, and examples include a cylindrical shape (e.g., a cylindrical shape, a polygonal cylindrical shape, etc.), a shape with a C-shaped cross section made by cutting a slit in the tube, and a coil shape made by winding a wire. Of these, a cylindrical shape is preferred.

Examples of materials that can be used to make radiopaque markers include radiopaque materials such as lead, barium, iodine, tungsten, gold, platinum, iridium, stainless steel, titanium, and cobalt-chromium alloys.

10 is a cross-sectional view showing another embodiment of the medical device 1, with the outer tubular member 50 and filament 60 not shown. As shown in FIG. 10, when the outer diameter of the inner tubular member 20 is CD2, the medical device 1 may have an expanding outer diameter region 22 in the distal portion of the inner tubular member 20, where the outer diameter CD2 increases toward the distal end 20b. This makes it easier for the distal portion of the inner tubular member 20 to abut against the lumen wall of the in-vivo indwelling tube 10, thereby reducing the misalignment between the axial center of the in-vivo indwelling tube 10 and the axial center of the inner tubular member 20. As a result, the guidewire 40 inserted from the distal end 10b of the in-vivo indwelling tube 10 can be easily inserted from the distal end 20b of the inner tubular member 20.

The position where the expanded outer diameter region 22 is formed is not particularly limited, and may be, for example, a section from the distal end 20b of the inner tube member 20 to a position 60 mm longitudinally away from the distal end 20b of the inner tube member 20 proximally, a section from the distal end 20b of the inner tube member 20 to a position 50 mm longitudinally away from the distal end 20b of the inner tube member 20 proximally, or a section from the distal end 20b of the inner tube member 20 to a position 40 mm longitudinally away from the distal end 20b of the inner tube member 20 proximally.

Figure 11 is a cross-sectional view showing another embodiment of the medical device 1, with the outer tubular member 50 and filament 60 not shown. As shown in Figure 11, when the inner diameter of the inner tubular member 20 is Cd1, the medical device 1 may have an expanding inner diameter region 23 at the distal end of the inner tubular member 20, where the inner diameter Cd1 increases toward the distal end 20b. This increases the opening at the distal end 20b of the inner tubular member 20, making it easier to insert the guidewire 40 inserted from the distal end 10b of the in-vivo indwelling tube 10 through the opening at the distal end 20b of the inner tubular member 20.

If the inner tube member 20 has an inner diameter expansion region 23, the outer diameter of the inner tube member 20 in the inner diameter expansion region 23 may increase toward the distal end 20b of the inner tube member 20, as shown in FIG. 11. In other words, the inner tube member 20 may have both an inner diameter expansion region 23 and an outer diameter expansion region 22.

The position where the expanded inner diameter region 23 is formed is not particularly limited, and may be, for example, a section from the distal end 20b of the inner tube member 20 to a position 60 mm longitudinally away from the distal end 20b of the inner tube member 20 proximally, a section from the distal end 20b of the inner tube member 20 to a position 50 mm longitudinally away from the distal end 20b of the inner tube member 20 proximally, or a section from the distal end 20b of the inner tube member 20 to a position 40 mm longitudinally away from the distal end 20b of the inner tube member 20 proximally.

Figure 12 is a cross-sectional view showing another embodiment of the medical device 1, with the outer tubular member 50 and filament 60 not shown. As shown in Figure 12, the medical device 1 may have an inner tubular member 20 at the distal end thereof having a taper 24 in which the outer diameter decreases toward the distal end 20b. This makes it less likely that the distal end 20b of the inner tubular member 20 will get caught on the inner wall of the outer tubular member 50 or the inner wall of the in-vivo indwelling tube 10 even if it comes into contact with it, thereby reducing the pull-out load of the inner tubular member 20 and improving operability for the operator.

Known resins can be used as the resin material for the inner tube member 20. Examples of resins include polyamide resins such as nylon; polyether polyamide resins; polyimide resins; polyester resins such as polyethylene terephthalate (PET); polyurethane resins; polyolefin resins such as polyethylene and polypropylene; fluorine-based resins such as polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), and ethylene tetrafluoroethylene copolymer (ETFE); polyvinyl chloride resins; silicone resins; and natural rubber. These may be used alone or in combination of two or more. Among these, polyamide resins, polyester resins, polyurethane resins, polyolefin resins, and fluorine-based resins are preferred.

The structure of the inner tube member 20 may be a single-layer structure or a multi-layer structure, with a single-layer structure being preferable. A single-layer structure allows for easy manufacturing. If it is a multi-layer structure, the resin materials constituting each layer may be the same or different.

The inner tubular member 20 may be constructed from a single tube from the proximal end 20a to the distal end 20b of the inner tubular member 20, or may be constructed by lining up and joining multiple tubes in the longitudinal direction. By being constructed from multiple tubes, the bending rigidity of the inner tubular member 20 can be changed in the longitudinal direction. For example, by making the hardness of the material of the tube that constitutes the distal portion of the inner tubular member 20 lower than the hardness of the material of the tube that constitutes the proximal portion of the inner tubular member 20, the inner tubular member 20 can have low bending rigidity in the distal portion and high bending rigidity in the proximal portion. Low bending rigidity in the distal portion of the inner tubular member 20 can improve followability to the guidewire 40. High bending rigidity in the proximal portion of the inner tubular member 20 can improve pushability.

The distal portion of the inner tube member 20 may be, for example, the region from the distal end 20b of the inner tube member 20 to a position that is 50% of the longitudinal length of the inner tube member 20. The proximal portion of the inner tube member 20 may be, for example, the region from the proximal end 20a of the inner tube member 20 to a position that is 50% of the longitudinal length of the inner tube member 20.

The in-vivo tube 10 may have drainage holes (through-holes) in the sidewall of the in-vivo tube 10. This allows fluid flowing within the body lumen to pass from the outside of the in-vivo tube 10 through the drainage holes into the inside of the in-vivo tube 10 and flow from the distal side to the proximal side of the in-vivo tube 10, making drainage possible even when the in-vivo tube 10 is placed within the body lumen.

The location of the drainage hole is not particularly limited; it may be located near the center of the in-vivo indwelling tube 10 in the longitudinal direction, or in the proximal and/or distal portions of the in-vivo indwelling tube 10.

The size (circle equivalent diameter) of the drainage hole is, for example, preferably 0.2 mm or more, more preferably 0.3 mm or more, even more preferably 0.5 mm or more, and is preferably 2.0 mm or less, more preferably 1.5 mm or less, even more preferably 1.3 mm or less.

The opening shape of the drainage hole can be, for example, circular, elliptical, rectangular (e.g., triangular, square, etc.). From the standpoint of ease of processing, circular or elliptical shapes are preferred for the opening shape of the drainage hole.

The number of drainage holes may be, for example, one, two or more, or five or more. The number of drainage holes is preferably, for example, 25 or less, more preferably 23 or less, and even more preferably 20 or less.

If the in-vivo tube 10 has multiple drainage holes, the size and opening shape of each hole may be the same or different. If the side wall of the in-vivo tube 10 has multiple drainage holes, the holes may be arranged in a row in the longitudinal direction of the in-vivo tube 10, in a row in the circumferential direction of the in-vivo tube 10, or in a spiral shape relative to the longitudinal direction of the in-vivo tube 10.

The in-vivo tube 10 may have a locking flap on the outer surface of the proximal portion and/or the outer surface of the distal portion of the in-vivo tube 10. Having a locking flap on the outer surface of the proximal portion of the in-vivo tube 10 can, for example, prevent the in-vivo tube 10 placed in the bile duct or pancreatic duct from entering the bile duct or pancreatic duct via the duodenal papilla. Having a locking flap on the outer surface of the distal portion of the in-vivo tube 10 can, for example, prevent the in-vivo tube 10 placed in the bile duct or pancreatic duct from falling into the duodenum. The in-vivo tube 10 may have a locking flap only on the outer surface of the proximal portion of the in-vivo tube 10, or may have a locking flap only on the outer surface of the distal portion of the in-vivo tube 10; however, it is preferable for the in-vivo tube 10 to have locking flaps on the outer surfaces of both the proximal and distal portions of the in-vivo tube 10.

The number of locking flaps arranged in the proximal portion of the in-vivo indwelling tube 10 and the number of locking flaps arranged in the distal portion of the in-vivo indwelling tube 10 may each be one, or, for example, two or more, or three or more, with five or less being preferred.

When multiple locking flaps are arranged in the proximal portion of the indwelling tube 10 or when multiple locking flaps are arranged in the distal portion of the indwelling tube 10, the locking flaps may be arranged at equal intervals around the circumference of the indwelling tube 10. This can improve the effectiveness of preventing the indwelling tube 10 from shifting out of position.

When multiple locking flaps are arranged in the proximal portion of the in-vivo indwelling tube 10 or when multiple locking flaps are arranged in the distal portion of the in-vivo indwelling tube 10, the length from the base to the free end of the locking flaps and the width and thickness of the locking flaps may all be the same or different. For example, if the length, width, and thickness of each locking flap are the same, manufacturing is easier. Furthermore, by making the length, width, and thickness of each locking flap different, the strength of each locking flap can be changed. As a specific example, the strength of locking flaps arranged in areas that are prone to stress and may break can be increased, and the strength of locking flaps arranged in areas that require flexibility can be decreased.

The locking flaps may be formed in the proximal and/or distal portions of the tube body, for example, by cutting a notch in the surface of the end of the tube body constituting the in-vivo placement tube 10 and causing a portion of the tube body to protrude diagonally outward relative to the tube body; alternatively, a locking flap member constituting the locking flaps may be disposed in the proximal and/or distal portions of the tube body as a separate member from the tube body constituting the in-vivo placement tube 10.

When a locking flap member is joined to the outer surface of the tube body to form a locking flap, the locking flap member may be made of the same material as the tube body or a different material, but it is preferable that the materials are the same. By making the materials the same, the bonding strength of the locking flap member to the tube body can be increased.

Methods for joining the tube body and the locking flap member include, for example, heat welding, ultrasonic welding, and bonding with adhesives, with heat welding being preferred. Joining the tube body and the locking flap member by heat welding can increase the bond strength between the tube body and the locking flap member.

It is preferable that the locking flap be formed by cutting a notch into the surface of the end of the tube body. This makes the locking flap less likely to fall off than if the locking flap were formed by joining the locking flap member to the outer surface of the tube body.

The locking flap located at the proximal portion of the indwelling tube 10 and the locking flap located at the distal portion of the indwelling tube 10 may be formed using the same method or different methods.

The in-vivo tube 10 may be, for example, a plastic tube stent placed in the bile duct or pancreatic duct. When the in-vivo tube 10 is a plastic tube stent placed in the bile duct, the side of the in-vivo tube 10 placed on the duodenum side is defined as the proximal side, and the opposite side (gallbladder side or liver side) is defined as the distal side. The distal end 10b of the in-vivo tube 10 may be placed on the gallbladder side or the liver side. When the distal end 10b of the in-vivo tube 10 is placed on the liver side, a portion of the distal portion of the in-vivo tube 10 may be placed in the hepatic duct.

The longitudinal length of the in-vivo indwelling tube 10 is not particularly limited, but may be, for example, 30 mm to 400 mm. The maximum outer diameter of the in-vivo indwelling tube 10 is not particularly limited, but may be, for example, 5 French to 11 French (approximately 1.7 mm to approximately 3.7 mm).

The resin material constituting the in vivo placement tube 10 can be any known resin, including, for example, polyamide resins such as nylon; polyether polyamide resins; polyimide resins; polyester resins such as polyethylene terephthalate (PET); polyurethane resins; polyolefin resins such as polyethylene and polypropylene; fluorine-based resins such as polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), and ethylene tetrafluoroethylene copolymer (ETFE); polyvinyl chloride resins; silicone resins; and natural rubber. These may be used alone or in combination. Among these, polyamide resins, polyurethane resins, polyolefin resins, and fluorine-based resins are particularly preferred. By including at least one of polyamide resins, polyurethane resins, polyolefin resins, and fluorine-based resins in the in vivo placement tube 10, both biocompatibility and flexibility of the in vivo placement tube 10 can be achieved.

The structure of the in-vivo indwelling tube 10 may be a single-layer structure or a multi-layer structure, with a single-layer structure being preferable. A single-layer structure allows for easy manufacturing. If it is a multi-layer structure, the resin materials constituting each layer may be the same or different.

The in-vivo indwelling tube 10 may be composed of a single tube from the proximal end 10a to the distal end 10b of the in-vivo indwelling tube 10, or may be composed of multiple tubes lined up and joined in the longitudinal direction.

The in-vivo tube 10 may have an arc portion that is curved in an arc shape when viewed from above. Having an arc portion can prevent the in-vivo tube 10, when placed in the bile duct or pancreatic duct, from falling out of the bile duct or pancreatic duct and toward the duodenum. The shape of the arc portion may be an arc shape such as an unclosed semicircle, or a closed circle. If the shape of the arc portion is an unclosed circle, the in-vivo tube 10 can be easily inserted into a biological lumen, etc. Furthermore, if the shape of the arc portion is a closed circle, the effect of fixing the in-vivo tube 10 in a predetermined position can be improved.

The resin material constituting the outer tube member 50 can be any known resin, including, for example, polyamide resins such as nylon; polyether polyamide resins; polyimide resins; polyester resins such as polyethylene terephthalate (PET); polyurethane resins; polyolefin resins such as polyethylene and polypropylene; fluorine-based resins such as polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), and ethylene tetrafluoroethylene copolymer (ETFE); polyvinyl chloride resins; silicone resins; and natural rubber. These may be used alone or in combination of two or more. Among these, polyamide resins, polyester resins, polyurethane resins, polyolefin resins, and fluorine-based resins are particularly preferred.

The structure of the outer tube member 50 may be a single-layer structure or a multi-layer structure, with a single-layer structure being preferable. A single-layer structure allows for easy manufacturing. If it is a multi-layer structure, the resin materials constituting each layer may be the same or different.

The outer tube member 50 may be constructed from a single tube extending from the proximal end 50a to the distal end of the outer tube member 50, or may be constructed by joining multiple tubes together in the longitudinal direction. By being constructed from multiple tubes, the bending rigidity of the outer tube member 50 can be varied in the longitudinal direction. For example, by making the hardness of the material of the tube constituting the distal portion of the outer tube member 50 lower than the hardness of the material of the tube constituting the proximal portion of the outer tube member 50, the outer tube member 50 can have a low bending rigidity in the distal portion and a high bending rigidity in the proximal portion. The low bending rigidity of the distal portion of the outer tube member 50 improves its ability to follow the guidewire. The distal portion of the outer tube member 50 may be, for example, the region from the distal end 50b of the outer tube member 50 to a position that is 50% of the longitudinal length of the outer tube member 50. The proximal portion of the outer tube member 50 may be, for example, the region from the proximal end 50a of the outer tube member 50 to a position that is 50% of the longitudinal length of the outer tube member 50. The resin material that constitutes the outer tube member 50 and the resin material that constitutes the inner tube member 20 may be the same or different.

The maximum outer diameter of the outer tube member 50 is not particularly limited as long as it is large enough to push the in-vivo indwelling tube 10 from the proximal side to the distal side. It may be larger, the same as, or smaller than the maximum outer diameter of the in-vivo indwelling tube 10, but it is more preferable that it be the same as the maximum outer diameter.

The number of through holes 58 in the outer tube member 50 is not particularly limited, but may be one, two, or three or more. When multiple through holes 58 are formed, the arrangement of the through holes 58 is not particularly limited, and they may be arranged in a row in the circumferential direction of the outer tube member 50 or in the longitudinal direction of the outer tube member 50.

The opening shape of the through hole 58 in the outer tube member 50, when viewed from above, may be, for example, circular, elliptical, oval, egg-shaped, polygonal, or a combination thereof.

The opening area of each of the through holes 58 of the outer tube member 50 may be, for example, 0.7 to 4.0 mm ² , 0.4 to 6.0 mm ² , or 0.1 to 8.0 mm ² when viewed in a plane of the outer tube member 50.

The area in which the through-holes 58 of the outer tube member 50 are arranged may be, for example, within an area 1 to 9 mm, 2 to 7 mm, or 3 to 5 mm away from the distal end 50b of the outer tube member 50 toward the proximal end 50a when viewed in plan.

The outer tube member 50 and the inner tube member 20 may be fixed on the proximal side. This can restrict the inner tube member 20 from moving distally in the longitudinal direction within the lumen of the in-vivo tube 10. When the outer tube member 50 is fixed on the proximal side, for example, the proximal end of the outer tube member 50 may be fixed to a handle or the like. There are no particular limitations on the method for fixing the proximal end of the outer tube member 50 to a handle or the like. For example, the handle body may be provided with a connection mechanism such as a luer lock, coupler, or other mating mechanism, and the proximal end of the outer tube member 50 may be fixed to the handle body via this.

This application claims the benefit of priority based on Japanese Patent Application No. 2024-56165, filed March 29, 2024. The entire contents of the specification of Japanese Patent Application No. 2024-56165 are incorporated herein by reference.

DESCRIPTION OF SYMBOLS 1 Medical device 10 In-vivo indwelling tube 10a Proximal end of in-vivo indwelling tube 10b Distal end of in-vivo indwelling tube 18, 18a, 18b Through-hole 20 Inner tubular member 20a Proximal end of inner tubular member 20b Distal end of inner tubular member 22 Expanded outer diameter region 23 Expanded inner diameter region 24 Taper 40 Guidewire 50 Outer tubular member 50a Proximal end of outer tubular member 50b Distal end of outer tubular member 58 Through-hole 59 Part of distal end portion of outer tubular member 60 Filament 60z Knot 61 Second filament 61a Closed loop 61b Thickened portion 61z Knot CD2 Outer diameter of inner tubular member Cd1 Inner diameter of inner tubular member

Claims (16)

an in-vivo indwelling tube having a longitudinal direction and a proximal end and a distal end;
an outer tubular member having a longitudinal direction;
an inner cylindrical member disposed in at least the inner cavity of the outer cylindrical member, the inner cylindrical member having a longitudinal direction and a proximal end and a distal end;
The filamentous membrane and
A medical device comprising:
the in-vivo indwelling tube has a through-hole in a side wall of a proximal portion of the in-vivo indwelling tube,
the outer tubular member has a through-hole in a side wall of a distal portion of the outer tubular member,
the filament passes through a through-hole of the indwelling tube and is formed into a closed ring, and a part of the proximal end of the indwelling tube is disposed in the ring;
The medical device has the loop of the filament passed through the through-hole of the outer tubular member, and the inner tubular member disposed within the loop. The medical device according to claim 1, wherein the thread body has a hook portion. The medical device according to claim 1, further comprising a second filament connected to the filament. The medical device according to claim 3, wherein the second filament has a hook portion. The medical device according to claim 2 or 4, wherein the catch portion is a portion of the thread body where frictional force is high, or a portion of the second thread body where frictional force is high. The medical device according to claim 2 or 4, wherein the hook portion is configured as a closed loop. The medical device according to claim 2 or 4, wherein the catch portion is a thickened portion of the thread body or a thickened portion of the second thread body. The medical device according to claim 2 or 4, wherein the hook portion is located in the proximal portion of the thread body or in the proximal portion of the second thread body. The medical device according to claim 1, wherein the inner tubular member is disposed in the lumen of the outer tubular member and the lumen of the indwelling tube, and is movable in the longitudinal direction of the indwelling tube. The medical device according to claim 9, wherein the distal end of the inner tube member cannot be moved distally beyond the distal end of the in-vivo indwelling tube. The medical device according to claim 1, wherein the inner cylindrical member has an X-ray opaque marker in a distal portion of the inner cylindrical member. The medical device according to claim 1, wherein the in-vivo indwelling tube has a drainage hole in the side wall of the in-vivo indwelling tube. The medical device according to claim 1, wherein the in-vivo indwelling tube has a locking flap on the outer surface of the proximal portion and/or the outer surface of the distal portion of the in-vivo indwelling tube. The medical device according to claim 1, wherein the in-vivo indwelling tube is a plastic tube stent placed in the bile duct or pancreatic duct. The medical device according to claim 1, wherein the in-vivo indwelling tube has an arcuate portion that is curved in an arc shape when viewed from above. 2. The medical device according to claim 1, wherein the inner cylindrical member has a tapered distal end portion where the outer diameter decreases toward the distal end.