WO2025074843A1 - Medical instrument - Google Patents

Abstract

The present invention provides a medical instrument including an in-vivo indwelling tube that is less likely to kink even when placed in a stenosis site or an occlusion site, that can ensure expansion of the stenosis site or the occlusion site, and that is easily inserted into the stenosis site or the occlusion site.　Provided is a medical instrument comprising: an in-vivo indwelling tube that has a longitudinal direction and that has a proximal end and a distal end; and an inner cylinder member that is disposed in a lumen of the in-vivo indwelling tube, that has a longitudinal direction, and that has a proximal end and a distal end, wherein the distal end of the inner cylinder member is disposed in a section M that is from the proximal end of the in-vivo indwelling tube and up to a position at which a length is 50% of the length L of said in-vivo indwelling tube in the longitudinal direction, and the maximum outer diameter CD1 at a distal end portion of the inner cylinder member is smaller than the maximum inner diameter Sd1 of said in-vivo indwelling tube in the section M of the in-vivo indwelling tube and is greater than an inner diameter Sd2 at a proximal portion of a section N up to the distal end of said in-vivo indwelling tube further toward the distal side than a distal end of the section M of the in-vivo indwelling tube.

Description

Medical Equipment

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

Body lumens such as blood vessels or digestive tracts such as the bile duct or pancreatic duct may become narrowed or blocked due to various causes. As a method for treating various diseases caused by narrowing or blocking, a method is known in which a tube-shaped stent is placed at the narrowed or blocked area to expand the narrowed or blocked area from the inside and widen the body lumen. For example, when narrowing or blocking occurs in the bile duct, a bile duct tube stent is delivered to the narrowed or blocked area. The tube stent delivered to the narrowed or blocked area is placed and pushes open the narrowed or blocked area from the inside. By placing the stent, the inner diameter of the bile duct at the narrowed or blocked area is expanded, and the narrowing or blocking is improved. As a result, bile can be discharged from the bile duct to the duodenum, and various diseases caused by narrowing or blocking of the bile duct, such as biliary atresia, jaundice, and biliary cancer, can be treated. Medical devices having such tube stents are described, for example, in Patent Documents 1 to 3.

Patent Document 1 describes a drainage tube retaining device (endoscopic treatment tool) that includes a guide catheter (elongated portion) through which a guidewire can be inserted and that slidably supports a drainage tube, a pusher tube (hollow portion) that is slidably arranged on the outside of the guide catheter, a pusher mouthpiece (connection portion) that is arranged at the rear end of the pusher tube and that positions the rear end of the pusher tube by connecting it to the operation portion of the endoscope so that the insertion direction of the pusher tube into the channel and the removal direction of the guide catheter from the channel relative to the pusher tube are approximately the same direction, and a mouthpiece that is arranged at the rear end of the guide catheter. In Patent Document 1, the guide catheter is long enough to protrude beyond the drainage tube when the pusher tube and the drainage tube are fitted over the outer circumferential surface of the guide catheter.

Patent document 2 describes a tube stent delivery device having an inner catheter on whose outer periphery a tube stent is attached so as to be freely axially movable at its distal end, and an outer catheter attached so as to be freely axially movable on the outer periphery of the inner catheter located on the proximal end side of the tube stent. In patent document 2, the inner catheter is capable of being inserted through the through hole of the tube stent.

Patent document 3 describes a stent kit that is composed of a tube stent having a stent arc portion, at least one end of which is made up of at least a portion of an arc, and an inner catheter that is formed with an inner arc portion of the same shape as the stent arc portion and is inserted into the inside of the tube stent so that the positions of the inner arc portion and the stent arc portion are aligned.

JP 2006-204476 A Patent No. 6322374 Patent No. 5408682

The endoscopic treatment tool described in Patent Document 1 has a guide catheter disposed in the inner cavity of a drainage tube, and the distal end of the guide catheter is configured to be movable distal to the distal end of the drainage tube. The tube stent transport device described in Patent Document 2 has an inner catheter disposed in the inner cavity of a tube stent, and the distal end of the inner catheter is configured to be movable distal to the distal end of the tube stent. Figure 1 of Patent Document 3 shows an embodiment in which an inner catheter 22 is inserted into a stent 12, and the distal end of the inner catheter 22 is disposed distal to the distal end of the stent 12. A similar embodiment is shown in Figure 5 of Patent Document 3. Thus, in Patent Documents 1 to 3, the distal end of an inner tube member such as a guide catheter or inner catheter disposed in the inner cavity of a tube stent is configured to be movable distal to the distal end of the tube stent. In order to move the inner tube member over the entire length of the tube stent, the inner diameter of the tube stent needs to be larger than the outer diameter of the inner tube member. On the other hand, in order to place a tube stent at a stenosis or occlusion site, it is necessary to deliver the tube stent to the stenosis or occlusion site, so it is preferable that the outer diameter of the tube stent is as small as possible. In order to reduce the outer diameter of the tube stent, the wall thickness of the tube stent can be reduced. However, if the wall thickness of the tube stent is reduced, the tube stent placed at the stenosis or occlusion site may kink, raising the risk of the tube stent becoming blocked.

Incidentally, a tube stent is inserted by inserting an inner tube member along a guide wire that has already been inserted into a biological lumen, and then inserting the tube stent along the inserted inner tube member. In this case, a step occurs between the guide wire and the inner tube member, and a step also occurs between the inner tube member and the tube stent, resulting in the presence of two steps. In particular, it has been reported that the latter step causes resistance to insertion in clinical practice, making it difficult to insert the tube stent into the narrowed or blocked area.

The present invention was made in consideration of the above-mentioned circumstances, and its purpose is to provide a medical device including an in-vivo placement tube that is unlikely to kink when placed in a stenotic or blocked area, can reliably expand the stenotic or blocked area, and can be easily inserted into the stenotic or blocked area.

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 an inner cavity of the in-vivo tube, the distal end of the inner tubular member being disposed in a section M from the proximal end of the in-vivo tube to a position which is 50% of the longitudinal length L of the in-vivo tube, the maximum outer diameter CD1 at the distal end of the inner tubular member being smaller than a maximum inner diameter Sd1 of the in-vivo tube in the section M of the in-vivo tube and larger than an inner diameter Sd2 of a proximal portion of a section N of the in-vivo tube that is distal to the distal end of the section M of the in-vivo tube and extends to the distal end of the in-vivo tube.
[2] The medical device according to [1], wherein the distal end of the inner tube member is located in a section M1 extending from a position where the length from the proximal end of the indwelling tube is 1% of the longitudinal length L of the indwelling tube to a position where the length is 50% of the longitudinal length L of the indwelling tube.
[3] The medical device according to [1] or [2], wherein a maximum outer diameter SD2 of the indwelling tube in the section N of the indwelling tube is smaller than a maximum outer diameter SD1 of the indwelling tube in the section M of the indwelling tube.
[4] The medical device according to any one of [1] to [3], further comprising an outer tube member having a longitudinal direction, the outer tube member being disposed outside the inner tube member proximal to the proximal end of the in-vivo indwelling tube, and the outer tube member and the inner tube member being fixed to each other on the proximal side.
[5] The medical device according to any one of [1] to [4], wherein the indwelling tube has a tapered region at a distal end of the indwelling tube, the outer diameter of which decreases toward the distal end.
[6] The medical device according to any one of [1] to [5], wherein the inner cylindrical member has an outer diameter increasing region at a distal end of the inner cylindrical member, the outer diameter of which increases toward the distal end.
[7] The medical device according to any one of [1] to [6], 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.
[8] The medical device according to any one of [1] to [7], wherein the inner cylindrical member has a taper at a distal end of the inner cylindrical member such that an outer diameter decreases toward the distal end.
[9] The medical device according to any one of [1] to [8], wherein the inner cylindrical member has an X-ray opaque marker at a distal end of the inner cylindrical member.
[10] The medical device according to any of [1] to [9], 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 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 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.
[11] The medical device according to any one of [1] to [10], wherein the in-vivo indwelling tube has a through-hole in a side wall of the in-vivo indwelling tube.
[12] The medical device according to any one of [1] to [11], wherein the indwelling tube has an engagement flap on the outer surface of the proximal end and/or the outer surface of the distal end of the indwelling tube.
[13] The medical device according to any one of [1] to [12], wherein the in-vivo indwelling tube is a plastic tube stent to be placed in the bile duct or pancreatic duct.
[14] The medical device according to any one of [1] to [13], wherein the in-vivo indwelling tube has an arcuate portion that is curved in an arc shape, and a non-arcuate portion proximal to the arcuate portion.
[15] The medical device according to [14], wherein the arc portion of the in-vivo indwelling tube is configured as a closed ring in a plan view.
[16] The medical device according to any of [1] to [15], further comprising an outer tube member having a longitudinal direction, and a thread, the outer tube member being disposed outside the inner tube member proximal to a proximal end of the indwelling tube and movable in the longitudinal direction of the inner tube member, the outer tube member having a through hole in a side wall of a distal portion of the outer tube member, the indwelling tube having a through hole in a side wall of a proximal portion of the indwelling tube, the thread being configured as a ring that passes through the through hole of the outer tube member and is closed, a part 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.

The medical device according to the present invention includes an in-vivo indwelling tube and an inner tubular member, and the inner tubular member is arranged not over the entire length of the in-vivo indwelling tube, but in a specific section of the in-vivo indwelling tube. As a result, the in-vivo indwelling tube can have a sufficient thickness in the section where the inner tubular member is not arranged, so that the in-vivo indwelling tube is less likely to kink when placed in a stenosed or blocked area, and the stenosed or blocked area can be reliably expanded. In addition, because the inner tubular member is not arranged over the entire length of the in-vivo indwelling tube, the distal end of the inner tubular member does not move distal to the distal end of the in-vivo indwelling tube. As a result, it is possible to eliminate the step between the inner tubular member and the in-vivo indwelling tube, which has traditionally been a cause of insertion resistance, and it is easier to insert the in-vivo indwelling tube into a stenosed or blocked area.

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

The medical device according to the embodiment of the present invention includes an in-vivo indwelling 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 indwelling tube, the distal end of the inner tubular member being disposed in a section M from the proximal end of the in-vivo indwelling tube to a position that is 50% of the longitudinal length L of the in-vivo indwelling tube, and the maximum outer diameter CD1 at the distal end of the inner tubular member is smaller than the maximum inner diameter Sd1 of the in-vivo indwelling tube in the section M of the in-vivo indwelling tube, and is larger than the inner diameter Sd2 at the proximal portion of the section N of the in-vivo indwelling tube that is distal to the distal end of the section M of the in-vivo indwelling tube and extends to the distal end of the in-vivo indwelling tube.

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

1 is a cross-sectional view showing an embodiment of a medical device according to the present invention. The medical device 1 shown in FIG. 1 includes an in-vivo indwelling tube 10 and an inner tubular member 20, and a part of the inner tubular member 20 is disposed in the lumen of the in-vivo indwelling tube 10. A guide wire 9 is disposed in the lumen of the in-vivo indwelling tube 10. The in-vivo 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 in-vivo indwelling tube 10 and the proximal end 20a of the inner tubular member 20 refer to one end on the user side (the surgeon side), and the distal end 10b of the in-vivo indwelling tube 10 and the distal end 20b of the inner tubular member 20 refer to one end on the opposite side to the proximal end (i.e., one 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 each referred to as the longitudinal direction.

The distal end 20b of the inner tube member 20 is located in section M, which is from the proximal end 10a of the in-vivo indwelling tube 10 to a position m where the length is 50% of the longitudinal length L of the in-vivo indwelling tube 10. This ensures a sufficient wall thickness for the in-vivo indwelling tube 10 distal to section M, making the in-vivo indwelling tube 10 less likely to kink when placed in a stenosed or blocked area, and ensuring that the stenosed or blocked area can be expanded. The longitudinal length L 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.

The maximum outer diameter CD1 at the distal end of the inner tube member 20 is smaller than the maximum inner diameter Sd1 of the in vivo retention tube 10 in section M of the in vivo retention tube 10 and is larger than the inner diameter Sd2 in the proximal portion of section N that is distal to the distal end of section M of the in vivo retention tube 10 and up to the distal end 10b of the in vivo retention tube 10. In other words, the relationship Sd2<CD1<Sd1 is established between the maximum outer diameter CD1 at the distal end of the inner tube member 20, the maximum inner diameter Sd1 in section M of the in vivo retention tube 10, and the inner diameter Sd2 in the proximal portion of section N up to the distal end 10b of the in vivo retention tube 10. As a result, the distal end of the inner tube member 20 does not move distal to the distal end of section M, i.e., distal to the distal end 10b of the in vivo retention tube 10. As a result, the step between the inner tube member 20 and the in-vivo indwelling tube 10, which has traditionally been a cause of resistance to insertion, can be eliminated, making it easier to insert the in-vivo indwelling tube 10 into the stenosed or blocked area.

The distal end of the inner tube member 20 refers to the region from the distal end 20b of the inner tube member 20 to a position 60 mm longitudinally proximally away from the distal end 20b of the inner tube member 20. The distal end of the inner tube member 20 may have an outer diameter expansion region or an inner diameter expansion region formed therein, as described below. The distal end of the inner tube member 20 may have an X-ray opaque marker formed therein, as described below.

The proximal portion of section N of the in-vivo indwelling tube 10 refers to the region from the distal end of section M of the in-vivo indwelling tube 10 that is within 5 mm of the longitudinal length L of the in-vivo indwelling tube 10.

The distal end 20b of the inner tube member 20 may be located in a section M1 from a position m1 where the length from the proximal end 10a of the in-vivo indwelling tube 10 is 1% of the longitudinal length L of the in-vivo indwelling tube 10 to a position m where the length is 50% of the longitudinal length L of the in-vivo indwelling tube 10. This can improve the pushability of the inner tube member 20. The distal end 20b of the inner tube member 20 may be located distal to a position where the length from the proximal end 10a of the in-vivo indwelling tube 10 is 5% of the longitudinal length L of the in-vivo indwelling tube 10, or the distal end 20b of the inner tube member 20 may be located distal to a position where the length from the proximal end 10a of the in-vivo indwelling tube 10 is 10% of the longitudinal length L of the in-vivo indwelling tube 10.

The length of the region in the longitudinal direction where the inner diameter of the in-vivo indwelling tube 10 is Sd1 may be, for example, 1% or more and 50% or less of the longitudinal length L of the in-vivo indwelling tube 10. The length of the region in the longitudinal direction where the inner diameter of the in-vivo indwelling tube 10 is Sd2 may be, for example, more than 50% of the longitudinal length L of the in-vivo indwelling tube 10.

The distal end 20b of the inner tube member 20 may or may not abut the inner wall of the in-vivo indwelling tube 10.

The in-vivo indwelling tube 10 shown in FIG. 1 has the same maximum outer diameter SD1 in section M and maximum outer diameter SD2 in section N. As shown in FIG. 1, the in-vivo indwelling tube 10 may have a reduced outer diameter region 15 at the distal end of the in-vivo indwelling tube 10, where the outer diameter SD3 decreases toward the distal end 10b. This makes it easier to insert the distal end of the in-vivo indwelling tube 10 into a narrowed or blocked area of the body lumen.

The distal end of the in-vivo indwelling tube 10 refers to the region from the distal end 10b of the in-vivo indwelling tube 10 to a position that is one-third of the longitudinal length L of the in-vivo indwelling tube 10. The proximal end of the in-vivo indwelling tube 10 refers to the region from the proximal end 10a of the in-vivo indwelling tube 10 to a position that is one-third of the longitudinal length L of the in-vivo indwelling tube 10. When the longitudinal length L of the in-vivo indwelling tube 10 is 180 mm or more, the region from the proximal end 10a of the in-vivo indwelling tube 10 to a position 60 mm away in the longitudinal direction on the distal side from the proximal end 10a of the in-vivo indwelling tube 10 may be defined as the proximal end of the in-vivo indwelling tube 10, and the region from the distal end 10b of the in-vivo indwelling tube 10 to a position 60 mm away in the longitudinal direction on the proximal side from the distal end 10b of the in-vivo indwelling tube 10 may be defined as the distal end of the in-vivo indwelling tube 10.

The position where the reduced outer diameter region 15 is formed may be, for example, a section from the distal end 10b of the in-vivo indwelling tube 10 to a position 60 mm longitudinally proximally from the distal end 10b of the in-vivo indwelling tube 10, a section from the distal end 10b of the in-vivo indwelling tube 10 to a position 50 mm longitudinally proximally, or a section from the distal end 10b of the in-vivo indwelling tube 10 to a position 40 mm longitudinally proximally from the distal end 10b of the in-vivo indwelling tube 10.

2 is a cross-sectional view showing another embodiment of the medical device according to the present invention. The same reference numerals are used for the same parts as in FIG. 1 to avoid duplicated explanation. The same applies below. As shown in FIG. 1, the maximum outer diameter SD2 in section N of the in-vivo indwelling tube 10 and the maximum outer diameter SD1 in section M of the in-vivo indwelling tube 10 may be the same size, but as shown in FIG. 2, the maximum outer diameter SD2 in section N of the in-vivo indwelling tube 10 may be smaller than the maximum outer diameter SD1 in section M of the in-vivo indwelling tube 10. In the medical device 1 according to the present invention, the distal end 20b of the inner tube member 20 is disposed in section M of the in-vivo indwelling tube 10, but not in section N of the in-vivo indwelling tube 10. Therefore, even if the maximum outer diameter SD2 in section N of the in-vivo indwelling tube 10 is smaller than the maximum outer diameter SD1 in section M, the wall thickness of the in-vivo indwelling tube 10 can be ensured. As a result, even if the in-vivo indwelling tube 10 is placed in a stenotic or obstructed area, it is less likely to kink, and the stenotic or obstructed area can be reliably expanded. In addition, by reducing the maximum outer diameter SD2 of the in-vivo indwelling tube 10 in section N, the in-vivo indwelling tube 10 can be placed in a thin organ such as the pancreatic duct. In addition, even if a locking flap is not provided at the proximal end of the in-vivo indwelling tube 10 as described below, by increasing the maximum outer diameter SD1 of the in-vivo indwelling tube 10 in section M, the in-vivo 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.

FIG. 3 is a cross-sectional view showing another embodiment of the medical device according to the present invention. The medical device 1 shown in FIG. 3 has a tube 10 to be placed in the body, and the tube 10 has a through hole in the side wall. The tube 10 has a locking flap 13a on the outer surface of the proximal end of the tube 10 to be placed in the body, and a locking flap 13b on the outer surface of the distal end. The inner tube member 20 of the medical device 1 shown in FIG. 3 has an X-ray opaque marker 17 at the distal end of the inner tube member 20. The inner tube member 20 has a small outer diameter region having an outer diameter smaller than the inner diameter at the proximal end 10a of the tube 10 to be placed in the body, and a large outer diameter region proximal to the small outer diameter region having an outer diameter larger than the inner diameter at the proximal end 10a of the tube 10 to be placed in the body, and the small outer diameter region and the large outer diameter region are arranged side by side in the longitudinal direction of the inner tube member 20.

As shown in FIG. 3, the in-vivo indwelling tube 10 may have a through hole 16 in the side wall of the in-vivo indwelling tube 10. This allows fluid flowing in the body lumen to pass from the outside of the in-vivo indwelling tube 10 through the through hole 16 into the inside of the in-vivo indwelling tube 10 and flow from the distal side to the proximal side of the in-vivo indwelling tube 10, making drainage possible even when the in-vivo indwelling tube 10 is placed in the body lumen. The position of the through hole 16 is not particularly limited, and it may be located near the center of the in-vivo indwelling tube 10 in the longitudinal direction as shown in FIG. 3, or it may be located at the proximal end and/or distal end of the in-vivo indwelling tube 10.

The size (circle equivalent diameter) of the through hole 16 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. In other words, the size (circle equivalent diameter) of the through hole 16 is preferably 0.2 mm to 2.0 mm, more preferably 0.3 mm to 1.5 mm, even more preferably 0.5 mm to 1.3 mm.

The opening shape of the through hole 16 can be, for example, a circle, an ellipse, or a rectangle (e.g., a triangle, a square, etc.). From the viewpoint of ease of processing, the opening shape of the through hole 16 is preferably a circle or an ellipse.

The number of through holes 16 may be, for example, 1, 2 or more, or 5 or more. For example, the number of through holes 16 is 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 in vivo retention tube 10 has multiple through holes 16, the size and opening shape of each through hole may be the same or different. When the in vivo retention tube 10 has multiple through holes 16, the through holes may be formed in a line in the longitudinal direction of the in vivo retention tube 10, may be formed in a line in the circumferential direction of the in vivo retention tube 10, or may be formed in a line in a spiral shape relative to the longitudinal direction of the in vivo retention tube 10.

As shown in FIG. 3, the in-vivo indwelling tube 10 may have locking flaps 13a and 13b. By having the locking flap 13a on the outer surface of the proximal end of the in-vivo indwelling tube 10, for example, the in-vivo 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. By having the locking flap 13b on the outer surface of the distal end of the in-vivo indwelling tube 10, for example, the in-vivo indwelling tube 10 placed in the bile duct or pancreatic duct can be prevented from falling off into the duodenum.

The in vivo placement tube 10 may have a locking flap 13a only on the outer surface of the proximal end of the in vivo placement tube 10, or may have a locking flap 13b only on the outer surface of the distal end of the in vivo placement tube 10. However, as shown in FIG. 3, it is preferable to have locking flaps on both the outer surface of the proximal end and the outer surface of the distal end of the in vivo placement tube 10.

The number of locking flaps 13a arranged at the proximal end of the in-vivo indwelling tube 10 and the number of locking flaps 13b arranged at the distal end of the in-vivo indwelling tube 10 may each be one, or, for example, two or more, or three or more, and preferably five or less. That is, they may be one to five, two to five, or three to five.

When multiple locking flaps 13a are provided at the proximal end of the in-vivo retention tube 10, or multiple locking flaps 13b are provided at the distal end of the in-vivo retention tube 10, it is preferable that each locking flap is arranged at equal intervals in the circumferential direction of the in-vivo retention tube 10. This can enhance the effect of preventing the in-vivo retention tube 10 from shifting out of position.

When multiple locking flaps 13a are arranged at the proximal end of the in-vivo retention tube 10, or multiple locking flaps 13b are arranged at the distal end of the in-vivo retention 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. Also, 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 where flexibility is required can be decreased.

The locking flap may be formed at the proximal end and/or distal end of the tube body by, for example, making a cut in the surface of the end of the tube body constituting the in vivo placement tube 10 and having a part of the tube body protrude diagonally outward relative to the tube body, or a locking flap member constituting the locking flap may be disposed at the proximal end and/or distal end of the tube body as a member separate from the tube body constituting the in vivo placement tube 10.

　The resin material constituting the in vivo placement tube 10 (i.e., the resin material constituting the tube body that is the raw material of the in vivo placement tube 10) can be a known resin, and examples thereof 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 may be used alone or in combination of two or more. Among them, polyamide-based resins, polyurethane-based resins, polyolefin-based resins, and fluorine-based resins are preferably used. By containing at least one of polyamide-based resins, polyurethane-based resins, polyolefin-based resins, and fluorine-based resins, the in vivo placement tube 10 can achieve both biocompatibility and flexibility.

The in vivo indwelling tube 10 may have a single-layer structure or a multi-layer structure, but a single-layer structure is preferable. A single-layer structure makes it easy to manufacture. If it has a multi-layer structure, the resin materials constituting each layer may be the same or different.

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

When the locking flap member is joined to the outer surface of the tube body to form the locking flap, the locking flap member may be the same as the material constituting the tube body or may be different, but it is preferable that the locking flap member is the same. By using the same material, 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 adhesion with adhesives, and joining by heat welding is 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.

The locking flap is preferably 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 was formed by joining the locking flap member to the outer surface of the tube body.

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

As shown in FIG. 3, the inner tube member 20 may have an X-ray opaque marker 17 at the distal end of the inner tube member 20. By having the X-ray opaque marker 17, the position of the inner tube member 20 can be confirmed under X-ray fluoroscopy.

The number of X-ray opaque markers 17 is not particularly limited, and may be one, two or more, or three or more. In FIG. 3, one is provided at the distal end of the inner tube member 20.

The shape of the X-ray opaque marker 17 is not particularly limited, and examples include a tubular shape (e.g., cylindrical, polygonal, etc.), a tubular shape with a cut to form a C-shaped cross section, and a coil shape made of wound wire. Of these, a tubular shape is preferred.

Examples of materials that make up the X-ray opaque marker 17 include X-ray opaque materials such as lead, barium, iodine, tungsten, gold, platinum, iridium, stainless steel, titanium, and cobalt-chromium alloys.

3, the inner tube member 20 may have a small outer diameter region 25 having an outer diameter smaller than the inner diameter at the proximal end 10a of the in-vivo retention 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 at the proximal end 10a of the in-vivo retention 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 tube member 20. In this way, when the inner tube member 20 is inserted into the lumen of the in-vivo retention tube 10, the small outer diameter region 25 of the inner tube member 20 is arranged in the lumen of the in-vivo retention tube 10. On the other hand, the distal end 20c of the large outer diameter region 26 of the inner tube member 20 abuts against the proximal end 10a of the in-vivo retention tube 10, so that the large outer diameter region 26 of the inner tube member 20 is not arranged in the lumen of the in-vivo retention tube 10. In this case, the inner tube member 20 plays the role of the outer tube member 50 described below and can also serve as a pusher member for the in-vivo indwelling tube 10.

FIG. 4 is a cross-sectional view showing another embodiment of the medical device according to the present invention, showing an enlarged view of the proximal end of the in-vivo indwelling tube 10 and the distal end of the inner tubular member 20. As shown in FIG. 4, when the outer diameter of the inner tubular member 20 is CD2, the inner tubular member 20 may have an outer diameter expansion region 22 at the distal end of the inner tubular member 20 where the outer diameter CD2 increases toward the distal end 20b. This makes it easier for the distal end of the inner tubular member 20 to abut against the lumen wall of the in-vivo indwelling tube 10, reducing the misalignment between the axis of the in-vivo indwelling tube 10 and the axis of the inner tubular member 20. As a result, the guide wire 9 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 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 away from the distal end 20b of the inner tube member 20 in the longitudinal direction proximal to the distal end 20b of the inner tube member 20, a section from the distal end 20b of the inner tube member 20 to a position 50 mm away from the distal end 20b of the inner tube member 20 in the longitudinal direction proximal to the distal end, or a section from the distal end 20b of the inner tube member 20 to a position 40 mm away from the distal end 20b of the inner tube member 20 in the longitudinal direction proximal to the distal end.

FIG. 5 is a cross-sectional view showing another embodiment of the medical device according to the present invention, showing an enlarged view of the proximal end of the in-vivo indwelling tube 10 and the distal end of the inner tubular member 20. As shown in FIG. 5, when the inner diameter at the distal end of the inner tubular member 20 is Cd1, the inner tubular member 20 may have an inner diameter expansion region 23 at the distal end of the inner tubular member 20 where the inner diameter Cd1 increases toward the distal end 20b. This makes the opening at the distal end 20b of the inner tubular member 20 larger, making it easier to insert the guidewire 9 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.

When the inner tube member 20 has an inner diameter expansion region 23, as shown in FIG. 5, it is preferable that the outer diameter of the inner tube member 20 in the inner diameter expansion region 23 of the inner tube member 20 increases toward the distal end 20b. That is, as shown in FIG. 5, the outer diameter of the inner tube member 20 in the inner diameter expansion region 23 may form an outer diameter expansion region.

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 away from the distal end 20b of the inner tube member 20 in the longitudinal direction proximal to the distal end 20b of the inner tube member 20, a section from the distal end 20b of the inner tube member 20 to a position 50 mm away from the distal end 20b of the inner tube member 20 in the longitudinal direction proximal to the distal end, or a section from the distal end 20b of the inner tube member 20 to a position 40 mm away from the distal end 20b of the inner tube member 20 in the longitudinal direction proximal to the distal end.

Figure 6 is a cross-sectional view showing another embodiment of the medical device according to the present invention, showing an enlarged view of the proximal end of the in-vivo indwelling tube 10 and the distal end of the inner tubular member 20. As shown in Figure 6, the inner tubular member 20 may have a taper 24 at the distal end of the inner tubular 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 tubular member 20 will get caught even if it comes into contact with the inner wall of the in-vivo indwelling tube 10, reducing the pull-out load of the inner tubular member 20 and improving operability for the operator.

FIG. 7 is a cross-sectional view showing another embodiment of the medical device according to the present invention. The medical device 1 shown in FIG. 7 includes an in-vivo indwelling tube 10 and an inner tubular member 20, with a portion of the inner tubular member 20 disposed within the lumen of the in-vivo indwelling tube 10. The in-vivo indwelling tube 10 has an arcuate portion A that is curved in an arc shape, and a non-arc portion B proximal to the arcuate portion A. Whether the in-vivo indwelling tube 10 belongs to the arcuate portion A or the non-arc portion B is determined by the following method.

<Judgment method>
8, a point to be determined on the central axis 11 of the indwelling tube 10 in a planar view is designated as point a, a point 2.5 mm away from point a in the proximal direction of the indwelling tube 10 along the central axis 11 is designated as point b, and a point 5 mm away from point a in the proximal direction of the indwelling tube 10 along the central axis 11 is designated as point c. A virtual circle 12 passing through points a, b, and c is created, and a line segment connecting point a and the center o of the virtual circle 12 is designated as line segment ao. A point on the virtual circle 12 that is closer to the proximal end 10a of the indwelling tube 10 than point a is defined as point x, and when the central angle with respect to the arc ax is 45°, if the indwelling tube 10 intersects with the line segment ox, it is determined that point a belongs to the arc portion A of the indwelling tube 10, and if the indwelling tube 10 does not intersect with the line segment ox, it is determined that point a belongs to the non-arc portion B of the indwelling tube 10. When the indwelling tube 10 intersects with the line segment ox, it means that a part of the indwelling tube 10 intersects with the line segment ox as shown in Fig. 8, or the entire indwelling tube 10 intersects with the line segment ox as shown in Fig. 9. When the indwelling tube 10 does not intersect with the line segment ox, it means that the indwelling tube 10 does not intersect with the line segment ox and is separated from the line segment ox as shown in Fig. 10.

When the in-vivo indwelling tube 10 has an arc portion A and a non-arc portion B, the inner tube member 20 may be arranged in a section M up to a position m where the length is 50% of the longitudinal length L of the in-vivo indwelling tube 10, and the inner tube member 20 may be arranged in the arc portion A of the in-vivo indwelling tube 10, or in the non-arc portion B, or in both the arc portion A and the non-arc portion B. As shown in FIG. 7, the inner tube member 20 is preferably arranged in at least a part of the non-arc portion B of the in-vivo indwelling tube 10, and not in the arc portion A of the in-vivo indwelling tube 10. This reduces the pull-out load of the inner tube member 20 when the in-vivo indwelling tube 10 is placed in the affected area, improving the operator's workability and making it easier to position the in-vivo indwelling tube 10. For example, if the in-vivo indwelling tube 10 is straight, friction between the in-vivo indwelling tube 10 and the inner tubular member 20 is small, so the pull-out load of the inner tubular member 20 when the in-vivo indwelling tube 10 is placed in the affected area can be reduced.

FIG. 11 is a cross-sectional view showing another embodiment of the medical device according to the present invention. The medical device 1 shown in FIG. 11 has a tube 10 to be placed in a living body and an inner tube member 20. The tube 10 to be placed in a living body has a locking flap 13a on the outer surface of the proximal end of the tube 10 to be placed in a living body. The tube 10 to be placed in a living body has an arc portion A that is curved in an arc shape, and a non-arc portion B proximal to the arc portion A. The arc portion A is configured in a closed ring shape in a plan view. This makes it possible to prevent the tube 10 to be placed in the bile duct or pancreatic duct from falling off from the bile duct or pancreatic duct into the duodenum.

When the in-vivo indwelling tube 10 has an arc portion A and a non-arc portion B, the inner tube member 20 may be arranged in a section M up to a position m where the length is 50% of the longitudinal length L of the in-vivo indwelling tube 10. The inner tube member 20 may be arranged in the arc portion A of the in-vivo indwelling tube 10, or in the non-arc portion B, or in both the arc portion A and the non-arc portion B. As shown in FIG. 11, the inner tube member 20 is preferably arranged in the non-arc portion B of the section M of the in-vivo indwelling tube 10, and not in the arc portion A. This reduces the pull-out load of the inner tube member 20 when the in-vivo indwelling tube 10 is placed in the affected area, improving the operator's workability and making it easier to position the in-vivo indwelling tube 10.

By providing an engagement flap 13a on the outer surface of the proximal end of the in-vivo indwelling tube 10, for example, the in-vivo 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.

If the in vivo placement tube 10 has an arc portion A, it may have a locking flap distal to the arc portion A, and the locking flap may be disposed on the outer surface of the distal end of the in vivo placement tube 10.

Fig. 12 is a cross-sectional view showing another embodiment of the medical device according to the present invention. The medical device 1 shown in Fig. 12 has an in-vivo indwelling tube 10 and an inner tubular member 20. The in-vivo indwelling tube 10 has an arcuate portion A that is curved in an arc shape, a non-arc portion B proximal to the arcuate portion A, and a proximal arcuate portion D proximal to the arcuate portion A.

When the in-vivo indwelling tube 10 has an arc portion A, a non-arc portion B, and a proximal arc portion D, the inner tube member 20 may be arranged in a section M up to a position m where the length is 50% of the longitudinal length L of the in-vivo indwelling tube 10. The inner tube member 20 may be arranged in the arc portion A of the in-vivo indwelling tube 10, in the non-arc portion B, in the proximal arc portion D, or in a plurality of these locations. As shown in FIG. 12, the inner tube member 20 is preferably arranged in the region of the non-arc portion B of the in-vivo indwelling tube 10 and in the section M, and is not arranged in the arc portion A. This reduces the pull-out load of the inner tube member 20 when the in-vivo indwelling tube 10 is placed in the affected area, improving the operator's workability and making it easier to position the in-vivo indwelling tube 10.

In addition, by disposing the inner tube member 20 in the inner cavity of the proximal arc portion D, pushability can be improved. The proximal arc portion D may be disposed on the duodenal side of the duodenal papilla, so that even if the inner tube member 20 is disposed in the inner cavity of the proximal arc portion D, the retention load is unlikely to be large.

As shown in FIG. 12, the arc portion A of the in-vivo indwelling tube 10 is configured as a closed ring in a plan view. By configuring the arc portion A as a closed ring in a plan view, for example, the in-vivo 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.

As shown in FIG. 12, the proximal arc portion D of the in-vivo placement 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 in-vivo placement 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.

13 is a cross-sectional view showing another embodiment of the medical device according to the present invention. As shown in FIG. 13, the medical device 1 may further include an outer tube member 50 having a longitudinal direction and a filament 60. The inner tube member 20 is arranged in the ring formed by the filament 60 to connect the in-vivo indwelling tube 10 and the outer tube member 50, so that a force applied from the hand side is easily transmitted to the in-vivo indwelling tube 10 through the outer tube member 50, and it is easy to push the in-vivo indwelling tube 10 distally to transport the in-vivo indwelling tube 10 to the affected area. When the medical device 1 includes the outer tube member 50, the outer tube member 50 is preferably arranged proximal to the proximal end 10a of the in-vivo indwelling tube 10 and outside the inner tube member 20. In this case, the outer tube member 50 is preferably configured to be movable in the longitudinal direction of the inner tube member 20.

The outer tube member 50 may have a through hole 72 in the side wall of the distal part of the outer tube member 50. The distal end of the outer tube member 50 refers to the region from the distal end of the outer tube member 50 to a position 60 mm away from the distal end of the outer tube member 50 in the longitudinal direction on the proximal side. The in-vivo retention tube 10 may have a through hole 71 in the side wall of the proximal part of the in-vivo retention tube 10. The thread 60 is configured as a ring that passes through the through hole 72 of the outer tube member 50 and is closed, and a part 51 of the distal end of the outer tube member 50 distal to the through hole 72 of the outer tube member 50 is arranged in the ring, and the ring of the thread 60 may be passed through the through hole 71 of the in-vivo retention tube 10, and the inner tube member 20 may be arranged in the ring. In this case, a part 14 of the proximal end of the in-vivo retention tube 10 is not arranged in the ring of the thread 60. In Fig. 13, the portion of the thread 60 present on the front side of the paper is indicated by a broken line so that the positional relationship between the thread 60 and the inner tubular member 20 can be easily understood. With this configuration, even after the in-vivo indwelling tube 10 is delivered to the affected area, the in-vivo indwelling tube 10 can be moved to the proximal side by pulling the inner tubular member 20 and the outer tubular member 50 to the proximal side, making it easier to position the in-vivo indwelling tube 10. In addition, the thread 60 is inserted into the through hole 72 of the outer tubular member 50, and the ring of the thread 60 is inserted into the through hole 71 of the in-vivo indwelling tube 10, making it easier to connect the in-vivo indwelling tube 10 and the outer tubular member 50 by the thread 60. In addition, the thread 60 is configured as a closed ring, and the inner tubular member 20 is arranged inside the ring, so that the connection between the in-vivo 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.

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.

The thread body 60 may be, for example, a suture. By using a suture as the thread body 60, the thread body 60 can be made flexible while maintaining its durability, making it less likely for the thread body 60 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 may be used alone or in combination of two or more types. Among these, polyamide-based resins, polyester-based resins, polyurethane-based resins, polyolefin-based resins, and fluorine-based resins are preferably used.

When the medical device 1 includes an outer tube member 50 having a longitudinal direction, the outer tube member 50 and the inner tube member 20 may be fixed at the proximal side. The movement of the inner tube member 20 in the longitudinal direction may be restricted by fixing the proximal side of the outer tube member 50 and the proximal side of the inner tube member 20. When the outer tube member 50 is fixed at 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 of 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.

The in-vivo placement tube 10 included in the medical device 1 in the embodiment of the present invention may be used, for example, as a plastic tube stent placed in the bile duct or pancreatic duct.

When the in-vivo indwelling tube 10 is placed in the bile duct, the side of the in-vivo indwelling tube 10 that is placed on the duodenum side is the proximal side, and the opposite side (the gallbladder side or the liver side) is the distal side, and the distal end 10b of the in-vivo indwelling tube 10 may be placed on the gallbladder side or on the liver side. When the distal end 10b of the in-vivo indwelling tube 10 is placed on the liver side, a part of the distal end of the in-vivo indwelling tube 10 may be placed in the hepatic duct.

The longitudinal length L 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 placement 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 inner tube member 20 may be any known resin, such as 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 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 resins are preferably used.

The inner tube member 20 may have a single-layer structure or a multi-layer structure, with a single-layer structure being preferable. A single-layer structure makes it easy to manufacture. If it has a multi-layer structure, the resin materials constituting each layer may be the same or different.

The inner tube member 20 may be a single tube from the proximal end 20a to the distal end 20b, or may be a combination of multiple tubes. By being made up of multiple tubes, the bending rigidity of the inner tube member 20 can be changed in the longitudinal direction. For example, by making the hardness of the material of the tube constituting the distal part of the inner tube member 20 lower than the hardness of the material of the tube constituting the proximal part of the inner tube member 20, the inner tube member 20 can have a low bending rigidity in the distal part and a high bending rigidity in the proximal part. The low bending rigidity of the distal part of the inner tube member 20 can improve the followability to the guidewire. The high bending rigidity of the proximal part of the inner tube member 20 can improve the pushability. The distal part of the inner tube member 20 refers to, 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 refers to, 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 resin material constituting the outer tube member 50 may be any known resin, such as 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 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 resins are preferably used.

The outer tube member 50 may have a single-layer structure or a multi-layer structure, but a single-layer structure is preferable. A single-layer structure makes it easy to manufacture. If it has a multi-layer structure, the resin materials constituting each layer may be the same or different.

The outer tube 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 tube member 50 can be changed in the longitudinal direction. The distal portion of the outer tube member 50 refers to, for example, the region from the distal end 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 refers to, for example, the region from the proximal end 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 constituting the outer tube member 50 and the resin material constituting 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, 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 is the same as the maximum outer diameter of the in-vivo indwelling tube 10.

This application claims the benefit of priority based on Japanese Patent Application No. 2023-171562, filed on October 2, 2023. The entire contents of the specification of the above-mentioned Japanese Patent Application No. 2023-171562 are incorporated by reference into this application.

LIST OF SYMBOLS 1 Medical device 9 Guide wire 10 Tube to be placed in a living body 10a Proximal end of tube to be placed in a living body 10b Distal end of tube to be placed in a living body 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 Outer diameter enlarged region of inner tubular member 23 Inner diameter enlarged region of inner tubular member 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 on the distal side of the through hole of the outer tubular member 60 Thread body 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 Maximum outer diameter at section M of the tube to be left in place in vivo SD2 Maximum outer diameter at section N of the tube to be left in place in vivo SD3 Outer diameter at the distal end of the tube to be left in place in vivo Sd1 Maximum inner diameter at section M of the tube to be left in place in vivo Sd2 Inner diameter at the proximal part of section N of the tube to be left in place in vivo a, b, c Point on the central axis of the tube to be left in place in vivo o Center of imaginary circle x Point on imaginary circle m Position where the length is 50% of the longitudinal length of the tube to be left in place in vivo m1 Position where the length is 1% of the longitudinal length of the tube to be left in place in vivo A Arc portion B Non-arc portion D Proximal arc portion L Length in the longitudinal direction of the tube to be left in place in vivo M Section N up to a position where the length is 50% of the longitudinal length of the indwelling tube N is a section distal to the distal end of section M of the indwelling tube up to the distal end of the indwelling tube

Claims (16)

an in-vivo indwelling tube having a longitudinal direction and a proximal end and a distal end;
a medical device including an inner tube member that is disposed in an inner cavity of the in-vivo indwelling tube, has a longitudinal direction, and has a proximal end and a distal end,
the distal end of the inner tube member is disposed in a section M from the proximal end of the indwelling tube to a position that is 50% of the longitudinal length L of the indwelling tube,
A medical device in which the maximum outer diameter CD1 at the distal end of the inner tube member is smaller than the maximum inner diameter Sd1 of the in-vivo in-vivo tube in the section M of the in-vivo ... The medical device according to claim 1, wherein the distal end of the inner tube member is located in a section M1 from a position where the length from the proximal end of the in-vivo indwelling tube is 1% of the longitudinal length L of the in-vivo indwelling tube to a position where the length is 50% of the longitudinal length L of the in-vivo indwelling tube. The maximum outer diameter SD2 of the indwelling tube in the section N of the indwelling tube is
The medical device according to claim 1 , wherein the outer diameter SD is smaller than a maximum outer diameter SD1 of the tube to be placed in the body in the section M of the tube to be placed in the body. The medical device further includes a barrel member having a longitudinal direction;
the outer tube member is disposed outside the inner tube member on a proximal side of a proximal end of the indwelling tube,
The medical device according to claim 1 , wherein the outer cylindrical member and the inner cylindrical member are fixed to each other at a proximal side. The medical device according to claim 1, wherein the in-vivo indwelling tube has a region of reduced outer diameter at the distal end of the in-vivo indwelling tube, the outer diameter of which decreases toward the distal end. The medical device according to claim 1, wherein the inner tube member has an outer diameter expansion region at the distal end of the inner tube member, the outer diameter of which increases toward the distal end. The medical device according to claim 1, wherein the inner tube member has an inner diameter expanding region at the distal end of the inner tube member, the inner diameter of which increases toward the distal end. The medical device according to claim 1, wherein the inner tube member has a taper at the distal end of the inner tube member such that the outer diameter decreases toward the distal end. The medical device according to claim 1, wherein the inner tube member has an X-ray opaque marker at the distal end of the inner tube member. 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 having an outer diameter larger than the inner diameter at the proximal end of the in-vivo indwelling tube, and the small outer diameter region and the large outer diameter region are arranged side by side in the longitudinal direction of the inner tube member. 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. 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. The medical device according to claim 1, wherein the in-vivo indwelling tube is a plastic tube stent that is placed in the bile duct or pancreatic duct. The medical device according to claim 1, wherein the in-vivo placement tube has an arcuate portion that is curved in an arc shape and a non-arc portion proximal to the arcuate portion. The medical device according to claim 14, wherein the arc portion of the in-vivo indwelling tube is configured as a closed ring in a plan view. The medical device further includes an outer tube member having a longitudinal direction and a filament;
the outer tube member is disposed outside the inner tube member proximal to a proximal end of the indwelling tube and is movable in a 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 in-vivo indwelling tube has a through-hole in a side wall of a proximal portion of the in-vivo indwelling tube,
the thread body is configured as a ring passing through the through hole of the outer tube member and closing the ring, and a part of the distal end portion of the outer tube member distal to the through hole of the outer tube member is disposed in the ring,
2. The medical device according to claim 1, wherein the loop of the filament is passed through a through-hole of the in-vivo indwelling tube, and the inner tubular member is disposed within the loop.

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