Medical instrument

Abstract

Provided is a medical instrument in which the pullout load exerted by an inner cylinder member when an in-vivo indwelling tube is indwelled in an affected area is low, and that offers improved ease of operation for an operator and allows easy positioning of the in-vivo indwelling tube.　A medical instrument (1) comprises: an in-vivo indwelling tube (10) having a longitudinal direction, and having a proximal end (10a) and a distal end (10b); and an inner cylinder member (20) disposed in the lumen of the in-vivo indwelling tube, having a longitudinal direction, and having a proximal end (20a) and a distal end (20b). The in-vivo indwelling tube has a circular arc part (A) curved in a circular arc shape and a non-circular arc part (B) located further toward the proximal side than the circular arc part. The inner cylinder member is disposed in at least a portion of the non-circular arc part, and is not disposed in the circular arc part.

Description

medical equipment

[0001] The present invention relates to a medical device including an in-vivo indwelling tube.

[0002] Living lumen such as blood vessels or digestive tracts, including the bile duct and pancreatic duct, may become narrowed or blocked for various reasons. A known method for treating various diseases caused by narrowing or obstruction involves placing a tubular stent at the narrowed or obstructed site to expand the narrowed or obstructed site from the inside and widen the living 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 and expands the narrowed or obstructed site from the inside. The 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 drain from the bile duct to the duodenum, enabling treatment of various diseases caused by narrowing or obstruction of the bile duct, such as biliary atresia, jaundice, and biliary tract cancer. Medical devices having such tube stents are described, for example, in Patent Documents 1 and 2.

[0003] 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 2 describes a medical device having a tubular indwelling device and an inner catheter inserted into the indwelling device. This medical device is characterized in that the indwelling device has a first bent portion pre-shaped into a bent shape, and the inner catheter has a second bent portion pre-shaped into a bent shape different from the first bent portion, and the second bent portion is inserted into the first bent portion.

[0004] Japanese Patent No. 5408682 JP 2022-52207 A

[0005] In the stent kit described in Patent Document 1, an inner catheter is disposed in the arc portion of the tube stent. In the medical device described in Patent Document 2, an inner catheter is disposed in the first bend portion of a tubular indwelling device. As described above, in Patent Documents 1 and 2, because the inner catheter is disposed in the arc portion of the tube stent or indwelling device, when the tube stent or indwelling device is placed in the affected area, the tube stent or indwelling device and the inner catheter tend to come into contact with each other, which increases the load when pulling the inner catheter out of the tube stent or indwelling device, making it difficult to operate. Furthermore, the increased pulling load makes it difficult to operate, so the placement position of the tube stent or indwelling device is likely to deviate from the desired position, making positioning difficult.

[0006] The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a medical device that requires a small pull-out load on the inner cylindrical member when placing an in-vivo indwelling tube in an affected area, that is easy for the operator to work with, and that makes it easy to position the in-vivo indwelling tube.

[0007] The present invention is as follows. [1] A medical device including an in-vivo tube having a longitudinal direction and a proximal end and a distal end, and an inner tubular member having a longitudinal direction and a proximal end and a distal end, the inner tubular member being disposed in the lumen of the in-vivo tube, the in-vivo tube having an arcuate portion curved in an arc shape and a non-arcuate portion proximal to the arcuate portion, the inner tubular member being disposed in at least a portion of the non-arcuate portion but not in the arcuate portion. [2] The medical device according to [1], the in-vivo tube having a proximal arcuate portion proximal to the arcuate portion, the inner tubular member being disposed in the proximal arcuate portion. [3] The medical device according to [1] or [2], the arcuate portion of the in-vivo tube having a closed ring shape in a plan view. [4] The medical device according to any one of [1] to [3], wherein the inner cylindrical member has an outer diameter expanding region at the distal end of the inner cylindrical member, where the outer diameter increases toward the distal end. [5] The medical device according to any one of [1] to [4], wherein the inner cylindrical member has an inner diameter expanding region at the distal end of the inner cylindrical member, where the inner diameter increases toward the distal end. [6] The medical device according to any one of [1] to [5], wherein the inner cylindrical member has a taper at the distal end of the inner cylindrical member, where the outer diameter decreases toward the distal end. [7] The medical device according to any one of [1] to [6], wherein the inner cylindrical member has an X-ray opaque marker at the distal end of the inner cylindrical member. [8] The medical device according to any one of [1] to [7], wherein the inner cylindrical member has a small outer diameter region having an outer diameter smaller than the inner diameter of the proximal end of the indwelling tube, and a large outer diameter region proximal to the small outer diameter region having an outer diameter larger than the inner diameter of the proximal end of the indwelling tube, the small outer diameter region and the large outer diameter region being arranged side by side in the longitudinal direction of the inner cylindrical member. [9] The medical device according to any one of [1] to [8], wherein the indwelling tube has a through-hole in its sidewall.

[10] The medical device according to any one of [1] to [9], wherein the indwelling tube has a locking flap on the outer surface of the proximal end and / or the outer surface of the distal end of the indwelling tube.

[11] The medical device according to any one of [1] to

[10] , wherein the in-vivo indwelling tube is a plastic tube stent to be placed in the bile duct or pancreatic duct.

[12] The medical device according to any of [1] to

[11] , further comprising an outer tubular member having a longitudinal direction, and a filament, the outer tubular member being disposed outside the inner tubular member proximal to the proximal end of the indwelling tube and movable in the longitudinal direction of the inner tubular member, the outer tubular member having a through-hole in a side wall of a distal portion of the outer tubular member, the indwelling tube having a through-hole in a side wall of a proximal portion of the indwelling tube, the filament being configured as a closed ring that passes through the through-hole of the outer tubular member, a part of the distal end of the outer tubular member distal to the through-hole of the outer tubular member being disposed within the ring, and the ring of the filament being passed through the through-hole of the indwelling tube, and the inner tubular member being disposed within the ring.

[0008] The medical device according to the present invention includes an in-vivo tube having an arcuate portion and a non-arcuate portion proximal to the arcuate portion, and an inner tubular member disposed in the lumen of the in-vivo tube, wherein the inner tubular member is disposed at a predetermined position on the in-vivo tube rather than over the entire length of the in-vivo tube. This reduces sliding friction caused by contact between the in-vivo tube and the inner tubular member, and reduces the pull-out load of the inner tubular member when placing the in-vivo tube in an affected area, improving operability for the operator and facilitating positioning of the in-vivo tube.

[0009] FIG. 1 is a cross-sectional view showing an embodiment of a medical device according to the present invention. FIG. 2 is a schematic view for explaining a determination method. FIG. 3 is a schematic view for explaining a determination method. FIG. 4 is a schematic view for explaining a determination method. FIG. 5 is a cross-sectional view showing another embodiment of a medical device according to the present invention. FIG. 6 is a cross-sectional view showing another embodiment of a medical device according to the present invention. FIG. 7 is a cross-sectional view showing another embodiment of a medical device according to the present invention. FIG. 8 is a cross-sectional view showing another embodiment of a medical device according to the present invention. FIG. 9 is a cross-sectional view showing another embodiment of a medical device according to the present invention. FIG. 10 is a cross-sectional view showing another embodiment of a medical device according to the present invention. FIG. 11 is a cross-sectional view showing another embodiment of a medical device according to the present invention. FIG. 12 is a cross-sectional view showing another embodiment of a medical device according to the present invention. FIG. 13 is a cross-sectional view showing another embodiment of a medical device according to the present invention. FIG. 14 is a cross-sectional view showing another embodiment of a medical device according to the present invention.

[0010] The medical device in an embodiment of the present invention is a medical device including an in-vivo tube having a longitudinal direction and a proximal end and a distal end, and an inner tubular member disposed in the lumen of the in-vivo tube and having a longitudinal direction and a proximal end and a distal end, wherein the in-vivo tube has an arc portion that is curved in an arc shape and a non-arc portion proximal to the arc portion, and the inner tubular member is disposed in at least a part of the non-arc portion and is not disposed in the arc portion.

[0011] The present invention will be described in more detail below based on the embodiments, but the present invention is not limited to the following embodiments. Of course, modifications can be made within the scope of the above and below-described purposes, and all such modifications are included within the technical scope of the present invention. In addition, hatching and component symbols may be omitted in the drawings for convenience. In such cases, reference should be made to the specification and other drawings. Furthermore, the dimensions of various components in the drawings may differ from actual dimensions, as priority is given to helping understand the features of the present invention.

[0012] Fig. 1 is a cross-sectional view showing an embodiment of a medical device according to the present invention. As shown in Fig. 1, the medical device 1 includes an indwelling tube 10 and an inner tubular member 20, with a portion of the inner tubular member 20 disposed within the lumen of the indwelling tube 10. The indwelling tube 10 has a longitudinal direction and a proximal end 10a and a distal end 10b. The inner tubular member 20 has a longitudinal direction and a proximal end 20a and a distal end 20b. The proximal end 10a of the indwelling tube 10 and the proximal end 20a of the inner tubular member 20 refer to ends on the user side (operator side), while the distal end 10b of the indwelling tube 10 and the distal end 20b of the inner tubular member 20 refer to ends opposite the proximal ends (i.e., ends on the treatment target side). The direction from the proximal end 10a to the distal end 10b of the indwelling tube 10 and the direction from the proximal end 20a to the distal end 20b of the inner cylindrical member 20 are each referred to as the longitudinal direction.

[0013] The indwelling tube 10 has an arcuate portion A that is curved in an arc shape, and a non-arcuate portion B that is proximal to the arcuate portion A. Whether the indwelling tube 10 belongs to the arcuate portion A or the non-arcuate portion B is determined by the following method. <Determination Method> As shown in Figure 2 , a point to be determined on the central axis 11 of the indwelling tube 10 in a planar view is defined as point a, a point 2.5 mm away from point a along the central axis 11 in the proximal direction of the indwelling tube 10 is defined as point b, and a point 5 mm away from point a along the central axis 11 in the proximal direction of the indwelling tube 10 is defined as point c. An imaginary circle 12 that passes through points a, b, and c is created, and a line segment connecting point a and the center o of the imaginary circle 12 is defined as line segment ao. Let point x be a point on the virtual circle 12 that is closer to the proximal end 10a of the indwelling tube 10 than point a, and when the central angle with respect to the arc ax is 45°, if the indwelling tube 10 intersects with the line segment ox, then point a is determined to belong to the arc portion A of the indwelling tube 10. If the indwelling tube 10 does not intersect with the line segment ox, then point a is determined to belong to the non-arc portion B of the indwelling tube 10. When the indwelling tube 10 intersects with the line segment ox, this means that a part of the indwelling tube 10 intersects with the line segment ox, as shown in Figure 2, or the entire indwelling tube 10 intersects with the line segment ox, as shown in Figure 3. When the indwelling tube 10 does not intersect with the line segment ox, then this means that the indwelling tube 10 and the line segment ox are separated from each other and do not intersect, as shown in Figure 4.

[0014] The inner tubular member 20 is disposed in at least a part of the non-circular portion B of the indwelling tube 10, but is not disposed in the circular portion A of the indwelling tube 10. This reduces the pull-out load of the inner tubular member 20 when the indwelling tube 10 is placed in the affected area, improving the operator's workability and facilitating positioning of the indwelling tube 10. When the indwelling tube 10 is disposed in the non-circular portion B, friction between the indwelling tube 10 and the inner tubular member 20 is small, so the pull-out load of the inner tubular member 20 when the indwelling tube 10 is placed in the affected area can be reduced. The inner tubular member 20 may be disposed in the entire non-circular portion B of the indwelling tube 10, as shown in FIG. 1 .

[0015] 5 is a cross-sectional view showing another embodiment of the medical device according to the present invention. The same reference numerals are used to designate the same parts as in FIG. 1 to avoid redundant explanation. The same applies hereinafter.

[0016] 5 has at least an inner diameter Sd1 and an inner diameter Sd2 smaller than the inner diameter Sd1, the position of the inner diameter Sd2 in the longitudinal direction being distal to the position of the inner diameter Sd1, and the maximum outer diameter CD1 at the distal end of the inner cylindrical member 20 may be smaller than the inner diameter Sd1 of the indwelling tube 10 and larger than the inner diameter Sd2 of the indwelling tube 10. By making the maximum outer diameter CD1 at the distal end of the inner cylindrical member 20 smaller than the inner diameter Sd1 of the indwelling tube 10, the inner cylindrical member 20 can be placed in the lumen of the indwelling tube 10. By making the maximum outer diameter CD1 at the distal end of the inner cylindrical member 20 larger than the inner diameter Sd2 of the indwelling tube 10, the distal end of the inner cylindrical member 20 abuts against the inner wall of the indwelling tube 10, making it possible to adjust the position of the distal end 20b of the inner cylindrical member 20 in the longitudinal direction. The distal end of the inner cylindrical member 20 refers to the region from the distal end 20b of the inner cylindrical member 20 to a position 60 mm longitudinally proximal to the distal end 20b of the inner cylindrical member 20. The distal end of the inner cylindrical member 20 may be disposed in the lumen of the indwelling tube 10. As described below, the distal end of the inner cylindrical member 20 may have an expanded outer diameter region or an expanded inner diameter region formed therein. As described below, the distal end of the inner cylindrical member 20 may have an X-ray opaque marker formed thereon.

[0017] The inner diameter of the indwelling tube 10 may be Sd1 at the non-circular portion B and Sd2 at the circular portion A. This allows the inner tube member 20 to be disposed in at least a part of the lumen of the non-circular portion B, but not disposed in the circular portion A.

[0018] The length of the longitudinal region of the in-vivo tube 10 where the inner diameter is Sd1 may be, for example, 10% or more of the length of the in-vivo tube 10, and the length of the longitudinal region of the in-vivo tube 10 where the inner diameter is Sd2 may be, for example, 10% or more of the length of the in-vivo tube 10.

[0019] The movement of the inner tubular member 20 in the distal longitudinal direction within the lumen of the indwelling tube 10 may be restricted. For example, as shown in FIG. 5 , the movement of the inner tubular member 20 may be restricted by using an indwelling tube 10 having at least inner diameters Sd1 and Sd2, and by ensuring that the maximum outer diameter CD1 at the distal end of the inner tubular member 20 satisfies the relationship of inner diameter Sd1 > maximum outer diameter CD1 > inner diameter Sd2. Alternatively, the movement of the inner tubular member 20 may be restricted by fixing the inner tubular member 20 to an outer tubular member 50 (described later) on the proximal side. When fixing the inner tubular member 20 on the proximal side, for example, the proximal end of the inner tubular member 20 may be fixed to a handle or the like. The method for fixing the proximal end of the inner tubular member 20 to a handle or the like is not particularly limited. For example, a connection mechanism such as a luer lock, a coupler, or other fitting mechanism may be provided on the handle body, and the proximal end of the inner tubular member 20 may be fixed to the handle body via this connection mechanism.

[0020] Figure 6 is a cross-sectional view showing another embodiment of the medical device according to the present invention. The medical device 1 shown in Figure 6 has an indwelling tube 10 and an inner tubular member 20. The indwelling tube 10 has an arcuate portion A that is curved in an arc, a non-arc portion B proximal to the arcuate portion A, and a distal arcuate portion C distal to the arcuate portion A. The inner tubular member 20 is disposed in the non-arc portion B, but not in the arcuate portion A. This reduces the pull-out load of the inner tubular member 20 when placing the indwelling tube 10 in an affected area, improving operability for the operator and facilitating positioning of the indwelling tube 10.

[0021] As shown in FIG. 6 , the distal arc portion C can prevent the in-vivo indwelling tube 10 placed in the bile duct or pancreatic duct from falling out of the bile duct or pancreatic duct into the duodenum.

[0022] Figure 7 is a cross-sectional view showing another embodiment of the medical device according to the present invention. The medical device 1 shown in Figure 7 has an indwelling tube 10 and an inner tubular member 20. The indwelling tube 10 has an arcuate portion A that is curved in an arc shape and a non-arcuate portion B that is proximal to the arcuate portion A. The inner tubular member 20 is disposed in the non-arcuate portion B, but not in the arcuate portion A. This reduces the pull-out load of the inner tubular member 20 when placing the indwelling tube 10 in the affected area, improving operability for the operator and facilitating positioning of the indwelling tube 10.

[0023] 7 is configured as a closed ring in plan view. By configuring the arc portion A as a closed ring in plan view, the in-vivo indwelling tube 10 placed in, for example, the bile duct or pancreatic duct can be prevented from falling out of the bile duct or pancreatic duct into the duodenum.

[0024] The indwelling tube 10 may have a locking flap, and for example, as shown in Fig. 7, the indwelling tube 10 may have a locking flap 13 at the non-circular portion B. It is more preferable that the locking flap 13 is provided on the outer surface of the proximal end of the indwelling tube 10. By providing the locking flap 13 on the outer surface of the proximal end of the indwelling tube 10, for example, the indwelling tube 10 placed in the bile duct or pancreatic duct can be prevented from entering the bile duct or pancreatic duct via the duodenal papilla.

[0025] When the indwelling tube 10 has the arcuate portion A, it may have a locking flap 13 distal to the arcuate portion A, and it is more preferable that the locking flap 13 be disposed on the outer surface of the distal end of the indwelling tube 10. By having the locking flap 13 on the outer surface of the distal end of the indwelling tube 10, it is possible to prevent the indwelling tube 10, which is disposed in the bile duct or pancreatic duct, from falling off into the duodenum, for example.

[0026] The indwelling tube 10 may have locking flaps 13 on both the outer surface of the distal end and the outer surface of the proximal end of the indwelling tube 10. The proximal end of the indwelling tube 10 refers to the region from the proximal end 10a of the indwelling tube 10 to a position one-third of the length of the indwelling tube 10, and the distal end of the indwelling tube 10 refers to the region from the distal end 10b of the indwelling tube 10 to a position one-third of the length of the indwelling tube 10. When the length of the indwelling tube 10 is 180 mm or more, the region from the proximal end 10a of the indwelling tube 10 to a position 60 mm away in the longitudinal direction distal to the proximal end 10a of the indwelling tube 10 may be defined as the proximal end of the indwelling tube 10, and the region from the distal end 10b of the indwelling tube 10 to a position 60 mm away in the longitudinal direction proximally from the distal end 10b of the indwelling tube 10 may be defined as the distal end of the indwelling tube 10.

[0027] The number of locking flaps 13 arranged at the distal end of the indwelling tube 10 and the number of locking flaps 13 arranged at the proximal end of the indwelling tube 10 may each be one, or, for example, two or more, or three or more, and is preferably five or less. That is, the number may be one to five, two to five, or three to five.

[0028] When multiple locking flaps 13 are provided at the distal end of the indwelling tube 10 or when multiple locking flaps 13 are provided at the proximal end of the indwelling tube 10, it is preferable that the locking flaps are arranged at equal intervals in the circumferential direction of the indwelling tube 10. This can improve the effect of preventing the indwelling tube 10 from shifting out of position.

[0029] When multiple locking flaps 13 are arranged at the distal end of the indwelling tube 10 or when multiple locking flaps 13 are arranged at the proximal end of the indwelling tube 10, the lengths from the bases to the free ends of the locking flaps 13 and the widths and thicknesses of the locking flaps 13 may all be the same or different. For example, if the locking flaps 13 have the same length, width, and thickness, manufacturing is easier. Furthermore, by varying the length, width, and thickness of the locking flaps 13, the strength of each locking flap 13 can be changed. As a specific example, the strength of locking flaps 13 arranged in areas that are prone to stress and are at risk of breaking can be increased, and the strength of locking flaps 13 arranged in areas requiring flexibility can be decreased.

[0030] The locking flap 13 may be formed at the distal end and / or proximal end of the tube body, for example, by making an incision in the surface of the end of the tube body constituting the in-vivo indwelling tube 10 and causing a part of the tube body to protrude diagonally outward relative to the tube body, or a locking flap member constituting the locking flap 13 may be disposed at the distal end and / or proximal end of the tube body as a member separate from the tube body constituting the in-vivo indwelling tube 10.

[0031] The resin material constituting the in-vivo indwelling tube 10 (i.e., the resin material constituting the tube body, which is the raw material for the in-vivo indwelling tube 10) can be any known resin, including 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 resins may be used alone or in combination. Among these, polyamide resins, polyurethane resins, polyolefin resins, and fluorine-based resins are preferred. By including at least one of polyamide resins, polyurethane resins, polyolefin resins, and fluorine-based resins in the in-vivo indwelling tube 10, both biocompatibility and flexibility of the in-vivo indwelling tube 10 can be achieved.

[0032] The in-vivo indwelling tube 10 may have a single-layer structure or a multi-layer structure, with a single-layer structure being preferred. A single-layer structure allows for easy manufacturing. In the case of a multi-layer structure, the resin materials constituting each layer may be the same or different.

[0033] The in-vivo indwelling tube 10 may be a single tube from the proximal end to the distal end, or may be made up of multiple tubes joined together.

[0034] When the locking flap member is bonded to the outer surface of the tube body to form the locking flap 13, 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, which increases the bonding strength of the locking flap member to the tube body.

[0035] The tube body and the locking flap member can be joined by, for example, heat welding, ultrasonic welding, or adhesive bonding, with heat welding being preferred. By joining the tube body and the locking flap member by heat welding, the joining strength between the tube body and the locking flap member can be increased.

[0036] The locking flap 13 is preferably formed by cutting a notch into the surface of the end of the tube body, which makes the locking flap 13 less likely to fall off than if the locking flap 13 were formed by joining the locking flap member to the outer surface of the tube body.

[0037] The locking flap 13 arranged at the distal end of the in-vivo indwelling tube 10 and the locking flap 13 arranged at the proximal end of the in-vivo indwelling tube 10 may be formed by the same method or by different methods.

[0038] Figure 8 is a cross-sectional view showing another embodiment of the medical device according to the present invention. The medical device 1 shown in Figure 8 has an indwelling tube 10 and an inner tubular member 20. The indwelling tube 10 has an arcuate portion A that is curved in an arc, a non-arc portion B proximal to the arcuate portion A, and a distal arcuate portion C distal to the arcuate portion A. The inner tubular member 20 is disposed in the non-arc portion B, but not in the arcuate portion A. This reduces the pull-out load of the inner tubular member 20 when placing the indwelling tube 10 in an affected area, improving operability for the operator and facilitating positioning of the indwelling tube 10.

[0039] 8 , the arc portion A of the indwelling tube 10 is configured as a closed ring in plan view. By configuring the arc portion A as a closed ring in plan view, for example, the indwelling tube 10 placed in the bile duct or pancreatic duct can be prevented from entering the bile duct or pancreatic duct through the duodenal papilla.

[0040] 8, the distal arcuate portion C of the indwelling tube 10 is configured as a closed ring. Because the distal arcuate portion C is configured as a closed ring in plan view, the indwelling tube 10 placed in the bile duct or pancreatic duct can be prevented from falling out of the bile duct or pancreatic duct into the duodenum, for example.

[0041] As shown in Fig. 8, the indwelling tube 10 may have a through-hole 16 in the side wall of the indwelling tube 10. This allows fluid flowing within a biological lumen to pass from the outside of the indwelling tube 10 through the through-hole 16 into the inside of the indwelling tube 10 and flow from the distal side to the proximal side of the indwelling tube 10, thereby enabling drainage even when the indwelling tube 10 is placed within a biological lumen. The position at which the through-hole 16 is located is not particularly limited. For example, as shown in Fig. 8, the through-hole 16 may be located in the distal arc portion C of the indwelling tube 10, in the section connecting arc portion A and distal arc portion C, or in arc portion A.

[0042] The size (circle-equivalent diameter) of the through-holes 16 is, for example, preferably 0.2 mm or more, more preferably 0.3 mm or more, and even more preferably 0.5 mm or more, and is preferably 2.0 mm or less, more preferably 1.5 mm or less, and even more preferably 1.3 mm or less. That is, the size (circle-equivalent diameter) of the through-holes 16 is preferably 0.2 mm to 2.0 mm, more preferably 0.3 mm to 1.5 mm, and even more preferably 0.5 mm to 1.3 mm.

[0043] Examples of the opening shape of the through-hole 16 include a circle, an ellipse, a rectangle (e.g., a triangle, a square, etc.), etc. The opening shape of the through-hole 16 is preferably a circle or an ellipse in terms of ease of processing.

[0044] The number of through holes 16 may be, for example, one, two or more, or five or more. The number of through holes 16 is, for example, preferably 25 or less. The number of through holes 16 is more preferably 23 or less, and even more preferably 20 or less. That is, the number of through holes 16 may be 1 to 25, 2 to 23, or 5 to 20. When the indwelling tube 10 has arc portions on both the proximal and distal sides as shown in FIG. 8 , the number of through holes 16 formed in arc portion A located on the proximal side may be, for example, 8 to 10, and the number of through holes 16 formed in arc portion C located on the distal side may be, for example, 6 to 7.

[0045] When the in-vivo indwelling tube 10 has a plurality of through-holes 16, the through-holes may have the same size and opening shape or may have different sizes and opening shapes. When the in-vivo indwelling tube 10 has a plurality of through-holes 16, the through-holes may be formed side by side in the longitudinal direction of the in-vivo indwelling tube 10, or may be formed side by side in the circumferential direction of the in-vivo indwelling tube 10, or may be formed side by side in a spiral shape relative to the longitudinal direction of the in-vivo indwelling tube 10.

[0046] 8, the inner cylindrical member 20 may have a radiopaque marker 17 at the distal end of the inner cylindrical member 20. By having the radiopaque marker 17, the position of the inner cylindrical member 20 can be confirmed under X-ray fluoroscopy.

[0047] The number of radiopaque markers 17 is not particularly limited, and may be one, two or more, or three or more. In FIG. 8, one radiopaque marker is provided at the distal end of the inner cylindrical member 20.

[0048] The shape of the radiopaque marker 17 is not particularly limited, and examples thereof include a cylindrical shape (e.g., a cylindrical shape, a polygonal cylindrical shape, etc.), a C-shaped cross section with a notch in the cylinder, a coil shape with a wound wire, etc. Among these, a cylindrical shape is preferable.

[0049] Examples of materials that can be used to form the radiopaque marker 17 include radiopaque materials such as lead, barium, iodine, tungsten, gold, platinum, iridium, stainless steel, titanium, and cobalt-chromium alloys.

[0050] Fig. 9 is a cross-sectional view showing another embodiment of the medical device according to the present invention. The medical device 1 shown in Fig. 9 includes an indwelling tube 10 and an inner tubular member 20. The indwelling tube 10 has an arcuate portion A, a non-arc portion B proximal to the arcuate portion A, and a proximal arcuate portion D proximal to the arcuate portion A. The inner tubular member 20 is disposed in the non-arc portion B but not in the arcuate portion A. This reduces the pull-out load of the inner tubular member 20 when placing the indwelling tube 10 in an affected area, improving operability for the operator and facilitating positioning of the indwelling tube 10. Furthermore, the inner tubular member 20 is disposed in the lumen of the proximal arcuate portion D, thereby improving pushability. The proximal arc portion D may be located closer to the duodenum than the duodenal papilla, which makes it difficult for the placement load to become large even if the inner tube member 20 is located in the lumen of the proximal arc portion D. In other words, if the indwelling tube 10 has multiple arc portions and has a non-arc portion B between adjacent arc portions, the inner tube member 20 may be located in at least a part of the non-arc portion B, but not in the most distal arc portion.

[0051] 9 , the arc portion A of the indwelling tube 10 is configured as a closed ring in plan view. By configuring the arc portion A as a closed ring in plan view, the indwelling tube 10 placed in, for example, the bile duct or pancreatic duct can be prevented from falling out of the bile duct or pancreatic duct into the duodenum.

[0052] 9 , the proximal arc portion D of the indwelling tube 10 is configured as a closed ring in plan view. By configuring the proximal arc portion D as a closed ring in plan view, for example, the indwelling tube 10 placed in the bile duct or pancreatic duct can be prevented from entering the bile duct or pancreatic duct via the duodenal papilla.

[0053] 10 is a cross-sectional view showing another embodiment of the medical device according to the present invention, showing an enlarged view of the distal end of the inner cylindrical member 20 and the in-vivo tube 10. As shown in FIG. 10 , when the outer diameter of the inner cylindrical member 20 is CD2, the inner cylindrical member 20 may have an expanding outer diameter region 22 at the distal end of the inner cylindrical member 20, in which the outer diameter CD2 increases toward the distal end 20b. This makes it easier for the distal end of the inner cylindrical member 20 to abut against the lumen wall of the in-vivo tube 10, thereby reducing the misalignment between the axial center of the in-vivo tube 10 and the axial center of the inner cylindrical member 20. As a result, the guidewire 9 inserted from the distal end 10b of the in-vivo tube 10 can be easily inserted from the distal end 20b of the inner cylindrical member 20.

[0054] The position at which the outer diameter expansion region 22 is formed is preferably, 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.

[0055] 11 is a cross-sectional view showing another embodiment of the medical device according to the present invention, showing an enlarged view of the distal end of the inner cylindrical member 20 and the indwelling tube 10. As shown in Fig. 11, when the inner diameter of the inner cylindrical member 20 is Cd1, the inner cylindrical member 20 may have an increasing inner diameter region 23 at the distal end of the inner cylindrical member 20, in which the inner diameter Cd1 increases toward the distal end 20b. This increases the opening at the distal end 20b of the inner cylindrical member 20, making it easier to insert the guidewire 9 inserted from the distal end 10b of the indwelling tube 10 through the opening at the distal end 20b of the inner cylindrical member 20.

[0056] When the inner cylindrical member 20 has the expanding inner diameter region 23, it is preferable that the outer diameter of the inner cylindrical member 20 at the expanding inner diameter region 23 of the inner cylindrical member 20 increases toward the distal end 20b, as shown in Fig. 11. That is, as shown in Fig. 11, the outer diameter of the inner cylindrical member 20 at the expanding inner diameter region 23 may form an expanding outer diameter region.

[0057] The position where the inner diameter expansion region 23 is formed is preferably, 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.

[0058] Figure 12 is a cross-sectional view showing another embodiment of the medical device according to the present invention, showing an enlarged view of the distal end of the inner cylindrical member 20 and the indwelling tube 10. As shown in Figure 12, the inner cylindrical member 20 may have a taper 24 at the distal end of the inner cylindrical member 20, in which the outer diameter decreases toward the distal end 20b. This makes it less likely that the distal end 20b of the inner cylindrical member 20 will get caught even if it comes into contact with the inner wall of the indwelling tube 10, thereby reducing the pull-out load of the inner cylindrical member 20 and improving operability for the operator.

[0059] Figure 13 is a cross-sectional view showing another embodiment of the medical device according to the present invention. The medical device 1 shown in Figure 13 has an indwelling tube 10 and an inner tubular member 20. The indwelling tube 10 has an arcuate portion A that is curved in an arc, a non-arcuate portion B proximal to the arcuate portion A, and a distal arcuate portion C distal to the arcuate portion A. The inner tubular member 20 is disposed in the non-arcuate portion B, but not in the arcuate portion A or the distal arcuate portion C. This reduces the pull-out load of the inner tubular member 20 when placing the indwelling tube 10 at an affected area, improving operability for the operator and facilitating positioning of the indwelling tube 10.

[0060] 13 , the inner tubular member 20 may have a small outer diameter region 25 having an outer diameter smaller than the inner diameter of the proximal end 10 a of the indwelling tube 10, and a large outer diameter region 26 proximal to the small outer diameter region 25 and having an outer diameter larger than the inner diameter of the proximal end 10 a of the indwelling tube 10, and the small outer diameter region 25 and the large outer diameter region 26 may be arranged side by side in the longitudinal direction of the inner tubular member 20. In this way, when the inner tubular member 20 is inserted into the lumen of the indwelling tube 10, the small outer diameter region 25 of the inner tubular member 20 is arranged in the lumen of the indwelling tube 10. On the other hand, the distal end 20 c of the large outer diameter region 26 of the inner tubular member 20 abuts against the proximal end 10 a of the indwelling tube 10, and therefore the large outer diameter region 26 of the inner tubular member 20 is not arranged in the lumen of the indwelling tube 10. In this case, the inner cylindrical member 20 serves as the outer cylindrical member 50 described below, and can also serve as a pusher member for the in-vivo indwelling tube 10 .

[0061] 13 , the arc portion A of the indwelling tube 10 is configured as a closed ring in plan view. By configuring the arc portion A as a closed ring in plan view, for example, the indwelling tube 10 placed in the bile duct or pancreatic duct can be prevented from entering the bile duct or pancreatic duct through the duodenal papilla.

[0062] 13 , the distal arcuate portion C of the indwelling tube 10 is configured as a closed ring. Because the distal arcuate portion C is configured as a closed ring in plan view, the indwelling tube 10 placed in the bile duct or pancreatic duct can be prevented from falling out of the bile duct or pancreatic duct into the duodenum, for example.

[0063] The medical device 1 according to the embodiment of the present invention may further include an outer tubular member 50 having a longitudinal direction. When the medical device 1 includes the outer tubular member 50, the outer tubular member 50 is preferably disposed proximal to the proximal end 10a of the indwelling tube 10 and outside the inner tubular member 20. In this case, the outer tubular member 50 is preferably configured to be movable in the longitudinal direction of the inner tubular member 20.

[0064] The proximal side of the outer tube member 50 may be fixed to the proximal side of the inner tube member 20, thereby restricting longitudinal movement of the inner tube member 20. 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. The method for fixing the proximal end of the outer tube member 50 to a handle or the like is not particularly limited, and for example, a connection mechanism such as a luer lock, coupler, or other fitting mechanism may be provided on the handle body, and the proximal end of the outer tube member 50 may be fixed to the handle body via this.

[0065] FIG. 14 is a cross-sectional view showing another embodiment of the medical device according to the present invention. As shown in FIG. 14 , the medical device 1 may further include an outer tubular member 50 having a longitudinal direction and a filament 60. The inner tubular member 20 is disposed within the loop formed by the filament 60 to connect the indwelling tube 10 and the outer tubular member 50. This allows force applied from the proximal side to be easily transmitted to the indwelling tube 10 through the outer tubular member 50, facilitating the operation of pushing the indwelling tube 10 distally to deliver the indwelling tube 10 to the affected area. When the medical device 1 includes the outer tubular member 50, the outer tubular member 50 is preferably disposed proximal to the proximal end 10 a of the indwelling tube 10 and outside the inner tubular member 20. In this case, the outer tubular member 50 is preferably configured to be movable in the longitudinal direction of the inner tubular member 20.

[0066] The outer tubular member 50 may have a through-hole 72 in the side wall of the distal portion of the outer tubular member 50. The distal portion of the outer tubular member 50 refers to the region from the distal end of the outer tubular member 50 to a position 60 mm longitudinally proximal to the distal end of the outer tubular member 50. The indwelling tube 10 may have a through-hole 71 in the side wall of the proximal portion of the indwelling tube 10. The thread 60 is configured as a closed ring that passes through the through-hole 72 of the outer tubular member 50, and a portion 51 of the distal end of the outer tubular member 50 distal to the through-hole 72 of the outer tubular member 50 is disposed within the ring. The ring of the thread 60 may be passed through the through-hole 71 of the indwelling tube 10, and the inner tubular member 20 may be disposed within the ring. In this case, a portion 14 of the proximal end of the inner tubular member 20 is not disposed within the ring of the thread 60. In Figure 14, the portion of the thread 60 on the front side of the drawing is indicated by a dashed line to facilitate understanding of the positional relationship between the thread 60 and the inner tubular member 20. With this configuration, even after the indwelling tube 10 has been delivered to the affected area, the indwelling tube 10 can be moved proximally by pulling the inner tubular member 20 and the outer tubular member 50 proximally, facilitating positioning of the indwelling tube 10. Furthermore, the thread 60 is inserted through the through-hole 71 of the indwelling tube 10 and the through-hole 72 of the outer tubular member 50, facilitating connection of the indwelling tube 10 and the outer tubular member 50 with the thread 60. Furthermore, because the thread 60 is configured as a closed ring and the inner tubular member 20 is positioned inside the ring, the connection between the indwelling tube 10 and the outer tubular member 50 can be easily released by removing the inner tubular member 20 from the ring. This makes it easier to place the in-vivo indwelling tube 10 in the affected area.

[0067] The diameter (wire diameter) of the thread body 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.

[0068] For example, a suture may be used as the thread body 60. When the thread body 60 is a suture, the thread body 60 can be made flexible while maintaining its durability, and therefore the thread body 60 can be made less likely to damage the in-vivo indwelling tube 10, the wall of a lumen in the body, or the like.

[0069] 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 preferred.

[0070] The in-vivo indwelling tube 10 may be used as a plastic tube stent to be placed in the bile duct or pancreatic duct, for example.

[0071] When the indwelling tube 10 is placed in the bile duct, the side of the indwelling tube 10 that is 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, and the distal end 10b of the indwelling tube 10 may be placed on the gallbladder side or the liver side. When the distal end 10b of the indwelling tube 10 is placed on the liver side, a portion of the distal end of the indwelling tube 10 may be placed in the hepatic duct.

[0072] The length of the in-vivo indwelling tube 10 is not particularly limited, but may be, for example, 30 mm to 400 mm. The length of the in-vivo indwelling tube 10 refers to the length of the path of the central axis of the in-vivo indwelling tube 10 in a plan view.

[0073] 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).

[0074] The in-vivo tube 10 may have a tapered outer diameter region where the outer diameter decreases toward the distal end 10b at the distal end of the in-vivo tube 10. By forming a tapered outer diameter region at the distal end of the in-vivo tube 10, the distal end of the in-vivo tube 10 can be easily inserted through a narrowed or blocked site in a body lumen.

[0075] Known resins can be used as the resin material constituting the inner tube member 20, 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 preferred.

[0076] The inner tube member 20 may have a single-layer structure or a multi-layer structure, with a single-layer structure being preferred. A single-layer structure allows for easy manufacturing. In the case of a multi-layer structure, the resin materials constituting each layer may be the same or different.

[0077] The inner cylindrical member 20 may be a single tube extending from the proximal end to the distal end, or may be formed by joining multiple tubes. By being composed of multiple tubes, the bending rigidity of the inner cylindrical member 20 can be varied along its longitudinal direction. For example, by making the hardness of the material of the tube constituting the distal portion of the inner cylindrical member 20 lower than that of the material of the tube constituting the proximal portion of the inner cylindrical member 20, the inner cylindrical member 20 can have low bending rigidity in the distal portion and high bending rigidity in the proximal portion. The low bending rigidity of the distal portion of the inner cylindrical member 20 can improve its ability to follow the guidewire. The high bending rigidity of the proximal portion of the inner cylindrical member 20 can improve its pushability. The distal portion of the inner cylindrical member 20 refers to, for example, the region from the distal end 20b of the inner cylindrical member 20 to a position that is 50% of the longitudinal length of the inner cylindrical member 20. The proximal portion of the inner cylindrical member 20 refers to, for example, a region from the proximal end 20 a of the inner cylindrical member 20 to a position that is 50% of the longitudinal length of the inner cylindrical member 20 .

[0078] Known resins can be used as the resin material constituting the outer tube member 50, 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 preferred.

[0079] The outer tube member 50 may have a single-layer structure or a multi-layer structure, with a single-layer structure being preferred. A single-layer structure allows for easy manufacturing. In the case of a multi-layer structure, the resin materials constituting each layer may be the same or different.

[0080] The outer tubular member 50 may be a single tube from the proximal end to the distal end, or may be made up of multiple tubes joined together. By being made up of multiple tubes, the bending rigidity of the outer tubular member 50 can be changed in the longitudinal direction. The distal portion of the outer tubular member 50 refers, for example, to the region from the distal end of the outer tubular member 50 to a position that is 50% of the longitudinal length of the outer tubular member 50. The proximal portion of the outer tubular member 50 refers, for example, to the region from the proximal end of the outer tubular member 50 to a position that is 50% of the longitudinal length of the outer tubular member 50.

[0081] The resin material constituting the outer cylindrical member 50 and the resin material constituting the inner cylindrical member 20 may be the same or different.

[0082] 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, and 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 of the in-vivo indwelling tube 10.

[0083] This application claims the benefit of priority based on Japanese Patent Application No. 2023-150941, filed on September 19, 2023. The entire contents of the specification of Japanese Patent Application No. 2023-150941 are incorporated herein by reference.

[0084] REFERENCE SIGNS LIST 1 Medical device 9 Guide wire 10 In-vivo indwelling tube 10a Proximal end of in-vivo indwelling tube 10b Distal end of in-vivo indwelling tube 11 Central axis 12 Virtual circle 13 Locking flap 14 Part of proximal end of inner tubular member 16 Through hole 17 X-ray opaque marker 20 Inner tubular member 20a Proximal end of inner tubular member 20b Distal end of inner tubular member 20c Distal end of large outer diameter region of inner tubular member 22 Expanded outer diameter region 23 Expanded inner diameter region 24 Taper 25 Small outer diameter region of inner tubular member 26 Large outer diameter region of inner tubular member 50 Outer tubular member 51 Part of distal end of outer tubular member distal to the through hole of the outer tubular member 60 Filament 71, 72 Through hole CD1 Maximum outer diameter at the distal end of the inner cylindrical member CD2: Outer diameter of the inner cylindrical member Cd1: Inner diameter at the distal end of the inner cylindrical member Sd1, Sd2: Inner diameter of the indwelling tube a, b, c: Points on the central axis of the indwelling tube o: Center of the imaginary circle x: Point on the imaginary circle A: Arc portion B: Non-arc portion C: Distal arc portion D: Proximal arc portion

Claims

1. A medical device comprising: a tube to be placed in a living body having a longitudinal direction and a proximal end and a distal end; and an inner tubular member disposed in an inner cavity of the tube to be placed in a living body, the inner tubular member having a longitudinal direction and a proximal end and a distal end, wherein the tube to be placed in a living body has an arc portion that is curved in an arc shape, and a non-arc portion proximal to the arc portion, and the inner tubular member is disposed in at least a portion of the non-arc portion, and is not disposed in the arc portion.

2. The medical device according to claim 1, wherein the in-vivo indwelling tube has a proximal arc portion proximal to the arc portion, and the inner tube member is disposed on the proximal arc portion.

3. The medical device according to claim 1, wherein the arcuate portion of the in-vivo indwelling tube is configured as a closed ring in a plan view.

4. The medical device according to claim 1, wherein the inner cylindrical member has an outer diameter expanding region at a distal end of the inner cylindrical member, the outer diameter of which increases toward the distal end.

5. The medical device according to claim 1, wherein the inner cylindrical member has an inner diameter expanding region at a distal end of the inner cylindrical member, the inner diameter of which increases toward the distal end.

6. The medical device according to claim 1, wherein said inner cylindrical member has a taper at a distal end of said inner cylindrical member such that an outer diameter decreases toward the distal end.

7. The medical device according to claim 1, wherein said inner cylindrical member has an X-ray opaque marker at a distal end of said inner cylindrical member.

8. The medical device according to claim 1, wherein the inner tube member has a small outer diameter region having an outer diameter smaller than the inner diameter at the proximal end of the in-vivo indwelling tube, and a large outer diameter region proximal to the small outer diameter region and having an outer diameter larger than the inner diameter at the proximal end of the in-vivo indwelling tube, the small outer diameter region and the large outer diameter region being arranged side by side in the longitudinal direction of the inner tube member.

9. The medical device according to claim 1, wherein the in-vivo indwelling tube has a through hole in the side wall of the in-vivo indwelling tube.

10. The medical device according to claim 1, wherein the in-vivo indwelling tube has a locking flap on the outer surface of the proximal end and / or the outer surface of the distal end of the in-vivo indwelling tube.

11. The medical device according to claim 1, wherein the in-vivo indwelling tube is a plastic tube stent to be placed in the bile duct or pancreatic duct.

12. The medical device according to claim 1, further comprising an outer tube member having a longitudinal direction, and a thread, wherein the outer tube member is disposed outside the inner tube member proximal to the proximal end of the indwelling tube and is movable in the longitudinal direction of the inner tube member, the outer tube member has a through hole in a side wall of a distal portion of the outer tube member, the indwelling tube has a through hole in a side wall of a proximal portion of the indwelling tube, the thread is configured as a ring that passes through the through hole of the outer tube member and is closed, and a portion of the distal end of the outer tube member distal to the through hole of the outer tube member is disposed within the ring, and the ring of the thread is passed through the through hole of the indwelling tube, and the inner tube member is disposed within the ring.

Images