Medical instrument

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

[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, dilating the narrowed or obstructed site from the inside, and widening 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. Placing the stent widens the inner diameter of the bile duct at the narrowed or obstructed site, thereby improving the narrowing or obstruction. This allows bile to be discharged from the bile duct to the duodenum, enabling the treatment of various diseases caused by narrowing or obstruction of the bile duct, such as biliary atresia, jaundice, and biliary tract cancer. Medical devices having such tube stents are described, for example, in Patent Documents 1 to 3.

[0003] 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 disposed on the outside of the guide catheter, a pusher mouthpiece (connection portion) that is disposed at the rear end of the pusher tube and that positions the rear end of the pusher tube by connecting it to the operation section 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, and a mouthpiece that is disposed 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 peripheral surface of the guide catheter.

[0004] Patent Document 2 describes a tube stent delivery device having an inner catheter with a tube stent attached to the outer periphery of its distal end so as to be freely axially movable, and an outer catheter attached to the outer periphery of the inner catheter located on the proximal end side of the tube stent so as to be freely axially movable. In Patent Document 2, the inner catheter is capable of being inserted through a through-hole in the tube stent.

[0005] Patent document 3 describes a stent kit comprising 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 having an inner arc portion of the same shape as the stent arc portion, the inner arc portion being inserted into the tube stent so that the positions of the inner arc portion and the stent arc portion are aligned.

[0006] Japanese Patent Publication No. 2006-204476 Japanese Patent No. 6322374 Japanese Patent No. 5408682

[0007] The endoscopic treatment tool described in Patent Document 1 has a guide catheter disposed in the lumen of a drainage tube, and the distal end of the guide catheter is configured to be movable distally beyond the distal end of the drainage tube. Patent Document 2 describes a tube stent delivery device having an inner catheter disposed in the lumen of a tube stent, and the distal end of the inner catheter is configured to be movable distally beyond 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 distally beyond the distal end of the stent 12. A similar embodiment is also shown in Figure 5 of Patent Document 3. Thus, in Patent Documents 1 to 3, the distal end of an inner tubular member, such as a guide catheter or inner catheter, disposed in the lumen of the tube stent is configured to be movable distally beyond the distal end of the tube stent. To move the inner tubular member over the entire length of the tube stent, the inner diameter of the tube stent must be larger than the outer diameter of the inner tubular 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 be as small as possible. The outer diameter of the tube stent can be reduced by reducing the wall thickness of the tube stent. However, if the wall thickness of the tube stent is reduced, the tube stent placed at the stenosis or occlusion site may kink, which may cause the tube stent to become blocked.

[0008] In the case of a tube stent, an inner cylindrical member is inserted along a guide wire that has been inserted into a living lumen in advance, and the tube stent is then inserted along the inserted inner cylindrical member. In this case, a step occurs between the guide wire and the inner cylindrical member, and a step also occurs between the inner cylindrical member and the tube stent, resulting in two steps. In particular, the latter step has been reported to cause insertion resistance in clinical practice, making it difficult to insert the tube stent into a stenotic or occluded area.

[0009] The present invention has been made in light of the above-mentioned circumstances, and its object is to provide a medical device including an in-vivo indwelling tube that is less likely to kink when placed in a stenotic or obstructed area, can reliably expand the stenotic or obstructed area, and can be easily inserted into the stenotic or obstructed area.

[0010] 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 lumen 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 that is 50% of the longitudinal length L of the in-vivo tube, and the maximum outer diameter CD1 at the distal end of the inner tubular member is smaller than a maximum inner diameter Sd1 of the in-vivo tube in the section M of the in-vivo tube and is larger than an inner diameter Sd2 of the in-vivo tube at a proximal portion of a section N 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 tubular member is located in a section M1 extending from the proximal end of the indwelling tube at a position corresponding to 1% of the longitudinal length L of the indwelling tube to a position corresponding to 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 of [1] to [3], wherein the medical device further includes an outer tubular member having a longitudinal direction, the outer tubular member being located outside the inner tubular member proximal to the proximal end of the indwelling tube, and the outer tubular member and the inner tubular member being fixed on the proximal side. [5] The medical device according to any one of [1] to [4], wherein the indwelling tube has a tapered outer diameter region at its distal end where the outer diameter decreases toward the distal end. [6] The medical device according to any one of [1] to [5], wherein the inner cylindrical member has an expanded outer diameter region at its distal end where the outer diameter increases toward the distal end. [7] The medical device according to any one of [1] to [6], wherein the inner cylindrical member has an expanded inner diameter region at its distal end where the inner diameter increases toward the distal end. [8] The medical device according to any one of [1] to [7], wherein the inner cylindrical member has a tapered outer diameter region at its distal end where the 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 its distal end.

[10] The medical device according to any one of [1] to [9], 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.

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

[10] , wherein the indwelling tube has a through-hole in its sidewall.

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

[11] , 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.

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

[12] , wherein the 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 indwelling tube has an arcuate portion curved in an arc shape and a non-arcuate portion proximal to the arcuate portion.

[15] The medical device according to

[14] , wherein the arcuate portion of the indwelling tube is configured as a closed ring in plan view.

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

[15] , 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.

[0011] The medical device according to the present invention includes an in-vivo tube and an inner tubular member, and the inner tubular member is disposed not over the entire length of the in-vivo tube but only in a specific section of the in-vivo tube. As a result, the wall of the in-vivo tube can be ensured in sections where the inner tubular member is not disposed, making the in-vivo tube less likely to kink when placed in a stenosis or occlusion site, and allowing the stenosis or occlusion site to be reliably expanded. Furthermore, because the inner tubular member is not disposed over the entire length of the in-vivo tube, the distal end of the inner tubular member does not move distally beyond the distal end of the in-vivo tube. As a result, the step between the inner tubular member and the in-vivo tube, which has traditionally caused insertion resistance, can be eliminated, making it easier to insert the in-vivo tube through the stenosis or occlusion site.

[0012] 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 a medical device according to the present invention. Fig. 3 is a cross-sectional view showing another embodiment of a medical device according to the present invention. Fig. 4 is a cross-sectional view showing another embodiment of a medical device according to the present invention. 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 schematic view for explaining a determination method. Fig. 9 is a schematic view for explaining a determination method. Fig. 10 is a schematic view for explaining a determination method. 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.

[0013] A medical device in an embodiment of the present invention includes 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 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 that is 50% of the longitudinal length L of the in-vivo tube, and the maximum outer diameter CD1 of the inner tubular member at the distal end is smaller than the maximum inner diameter Sd1 of the in-vivo tube in section M of the in-vivo tube and is larger than an inner diameter Sd2 of the in-vivo tube at a proximal portion of section N that is distal to the distal end of section M of the in-vivo tube and extends to the distal end of the in-vivo tube.

[0014] 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.

[0015] FIG. 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 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. A guidewire 9 is 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.

[0016] The distal end 20b of the inner cylindrical member 20 is located in a section M extending from the proximal end 10a of the indwelling tube 10 to a position m that is 50% of the longitudinal length L of the indwelling tube 10. This ensures a sufficient wall thickness of the indwelling tube 10 distal to section M, making the indwelling tube 10 less likely to kink even when placed in a stenotic or obstructed area, and ensuring reliable dilation of the stenotic or obstructed area. The longitudinal length L of the indwelling tube 10 refers to the length of the path along the central axis of the indwelling tube 10 in a plan view.

[0017] The maximum outer diameter CD1 at the distal end of the inner cylindrical member 20 is smaller than the maximum inner diameter Sd1 of the retained tube 10 in section M of the retained tube 10 and is larger than the inner diameter Sd2 of a proximal portion of section N that is distal to the distal end of section M of the retained tube 10 and extends to the distal end 10b of the retained tube 10. In other words, the relationship Sd2<CD1<Sd1 holds among the maximum outer diameter CD1 at the distal end of the inner cylindrical member 20, the maximum inner diameter Sd1 of the retained tube 10 in section M, and the inner diameter Sd2 of the proximal portion of section N that extends to the distal end 10b of the retained tube 10. As a result, the distal end of the inner cylindrical member 20 does not move distal to the distal end of section M, i.e., distal to the distal end 10b of the retained tube 10. As a result, the step between the inner tube member 20 and the in-vivo indwelling tube 10, which has conventionally been a cause of insertion resistance, can be eliminated, making it easier to insert the in-vivo indwelling tube 10 into the narrowed or blocked area.

[0018] 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. As will be described later, an outer diameter expansion region or an inner diameter expansion region may be formed at the distal end of the inner cylindrical member 20. As will be described later, an X-ray opaque marker may be formed at the distal end of the inner cylindrical member 20.

[0019] The proximal portion of section N of the indwelling tube 10 refers to a region from the distal end of section M of the indwelling tube 10 that is within 5 mm of the longitudinal length L of the indwelling tube 10 .

[0020] The distal end 20b of the inner cylindrical member 20 may be located in a section M1 from a position m1 where the length from the proximal end 10a of the indwelling tube 10 is 1% of the longitudinal length L of the indwelling tube 10 to a position m where the length is 50% of the longitudinal length L of the indwelling tube 10. This increases the pushability of the inner cylindrical member 20. The distal end 20b of the inner cylindrical member 20 may be located distal to a position where the length from the proximal end 10a of the indwelling tube 10 is 5% of the longitudinal length L of the indwelling tube 10, or the distal end 20b of the inner cylindrical member 20 may be located distal to a position where the length from the proximal end 10a of the indwelling tube 10 is 10% of the longitudinal length L of the indwelling tube 10.

[0021] The length of the longitudinal region of the indwelling tube 10 where the inner diameter is Sd1 may be, for example, 1% or more and 50% or less of the longitudinal length L of the indwelling tube 10. The length of the longitudinal region of the indwelling tube 10 where the inner diameter is Sd2 may be, for example, more than 50% of the longitudinal length L of the indwelling tube 10.

[0022] The distal end 20b of the inner cylindrical member 20 may or may not abut against the inner wall of the indwelling tube 10.

[0023] The 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 indwelling tube 10 may have a tapered outer diameter region 15 at the distal end of the 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 indwelling tube 10 through a narrowed or blocked site in a body lumen.

[0024] 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 longitudinal length L 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 longitudinal length L of the indwelling tube 10. When the longitudinal length L 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.

[0025] The position where the reduced outer diameter region 15 is formed may be, for example, a section from the distal end 10b of the indwelling tube 10 to a position 60 mm longitudinally proximally from the distal end 10b of the indwelling tube 10, a section from the distal end 10b of the indwelling tube 10 to a position 50 mm longitudinally proximally, or a section from the distal end 10b of the indwelling tube 10 to a position 40 mm longitudinally proximally from the distal end 10b of the indwelling tube 10.

[0026] Figure 2 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 components as in Figure 1 to avoid redundant description. The same applies hereinafter. As shown in Figure 1, the maximum outer diameter SD2 in section N of the indwelling tube 10 and the maximum outer diameter SD1 in section M of the indwelling tube 10 may be the same. However, as shown in Figure 2, the maximum outer diameter SD2 in section N of the indwelling tube 10 may be smaller than the maximum outer diameter SD1 in section M of the indwelling tube 10. In the medical device 1 according to the present invention, the distal end 20b of the inner tubular member 20 is disposed in section M of the indwelling tube 10, but not in section N of the indwelling tube 10. Therefore, even if the maximum outer diameter SD2 in section N of the indwelling tube 10 is smaller than the maximum outer diameter SD1 in section M, the wall thickness of the indwelling tube 10 can be ensured. As a result, the indwelling tube 10 is less likely to kink even when placed in a stenotic or obstructed area, allowing the stenotic or obstructed area to be reliably dilated. Furthermore, by reducing the maximum outer diameter SD2 of the indwelling tube 10 in section N, the indwelling tube 10 can be placed in a narrow organ such as the pancreatic duct. Furthermore, by increasing the maximum outer diameter SD1 of the indwelling tube 10 in section M, 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, even without providing a locking flap at the proximal end of the indwelling tube 10, as will be described later.

[0027] Figure 3 is a cross-sectional view showing another embodiment of the medical device according to the present invention. The medical device 1 shown in Figure 3 has an indwelling tube 10, which has a through-hole in its sidewall. The indwelling tube 10 has a locking flap 13a on the outer surface of the proximal end of the indwelling tube 10 and a locking flap 13b on the outer surface of the distal end. The inner tubular member 20 of the medical device 1 shown in Figure 3 has an X-ray opaque marker 17 at its distal end. The inner tubular member 20 has a small outer diameter region having an outer diameter smaller than the inner diameter at the proximal end 10a of the indwelling tube 10, 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 indwelling tube 10, the small outer diameter region and the large outer diameter region being aligned in the longitudinal direction of the inner tubular member 20.

[0028] As shown in Figure 3, 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 left in a biological lumen. The position at which the through-hole 16 is provided is not particularly limited, and it may be provided near the center in the longitudinal direction of the indwelling tube 10 as shown in Figure 3, or it may be provided at the proximal end and / or distal end of the indwelling tube 10.

[0029] 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.

[0030] 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.

[0031] The number of through holes 16 may be, for example, 1, 2 or more, or 5 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.

[0032] 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.

[0033] 3, the indwelling tube 10 may have locking flaps 13a and 13b. By providing the locking flap 13a on the outer surface of the proximal end of the indwelling tube 10, it is possible to prevent, for example, the indwelling tube 10 placed in the bile duct or pancreatic duct from entering the bile duct or pancreatic duct via the duodenal papilla. By providing the locking flap 13b on the outer surface of the distal end of the indwelling tube 10, it is possible to prevent, for example, the indwelling tube 10 placed in the bile duct or pancreatic duct from falling off into the duodenum.

[0034] The in-vivo tube 10 may have a locking flap 13a only on the outer surface of the proximal end of the in-vivo tube 10, or may have a locking flap 13b only on the outer surface of the distal end of the in-vivo tube 10. However, as shown in Figure 3, it is preferable that the in-vivo tube 10 have locking flaps on both the outer surfaces of the proximal end and the distal end.

[0035] The number of locking flaps 13a arranged at the proximal end of the indwelling tube 10 and the number of locking flaps 13b arranged at the distal end of the indwelling tube 10 may each be 1, or, for example, 2 or more, or 3 or more, and preferably 5 or less. That is, the number may be 1 to 5, 2 to 5, or 3 to 5.

[0036] When multiple locking flaps 13a are provided at the proximal end of the indwelling tube 10 or multiple locking flaps 13b are provided at the distal 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.

[0037] When multiple locking flaps 13a are disposed at the proximal end of the indwelling tube 10 or when multiple locking flaps 13b are disposed at the distal end of the indwelling tube 10, the lengths from the bases to the free ends of the locking flaps and the widths and thicknesses of the locking flaps may all be the same or different. For example, if the lengths, widths, and thicknesses of the locking flaps are the same, manufacturing is easier. Furthermore, by varying the lengths, widths, and thicknesses of the locking flaps, the strength of each locking flap can be changed. For example, the strength of locking flaps disposed in areas prone to stress and risk of breakage can be increased, while the strength of locking flaps disposed in areas requiring flexibility can be decreased.

[0038] The locking flap may be formed at the proximal end and / or distal 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 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 indwelling tube 10.

[0039] 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.

[0040] 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 allows for easy manufacturing. When the tube has a multi-layer structure, the resin materials constituting each layer may be the same or different.

[0041] The in-vivo indwelling tube 10 may be a single tube extending from the proximal end 10a to the distal end 10b, or may be formed by joining a plurality of tubes.

[0042] When the locking flap is formed by joining the locking flap member to the outer surface of the tube body, 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.

[0043] 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.

[0044] The locking flaps are preferably formed by cutting into the surface of the end of the tube body, which makes them less likely to fall off than locking flaps formed by joining locking flap members to the outer surface of the tube body.

[0045] The locking flap 13a arranged at the proximal end of the indwelling tube 10 and the locking flap 13b arranged at the distal end of the indwelling tube 10 may be formed by the same method or by different methods.

[0046] 3, 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. 3, 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] 3 , 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 .

[0051] 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 indwelling tube 10 and the distal end of the inner cylindrical member 20. As shown in FIG. 4 , 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 indwelling tube 10, thereby reducing the misalignment between the axial center of the inner cylindrical member 20 and that of the inner cylindrical member 20. As a result, the guidewire 9 inserted from the distal end 10b of the indwelling tube 10 can be easily inserted from the distal end 20b of the inner cylindrical member 20.

[0052] 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.

[0053] 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 indwelling tube 10 and the distal end of the inner cylindrical member 20. As shown in Fig. 5, when the inner diameter at the distal end 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.

[0054] 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. 5. That is, as shown in Fig. 5, the outer diameter of the inner cylindrical member 20 at the expanding inner diameter region 23 may form an expanding outer diameter region.

[0055] 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.

[0056] 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 indwelling tube 10 and the distal end of the inner cylindrical member 20. As shown in Figure 6, 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 on the inner wall of the indwelling tube 10 even if it comes into contact with it, thereby reducing the pull-out load of the inner cylindrical member 20 and improving operability for the operator.

[0057] 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 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 an arcuate portion A that is curved in an arc shape, and a non-arcuate portion B located 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.

[0058] 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 along the central axis 11 in the proximal direction of the indwelling tube 10 is designated 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 designated as point c. An imaginary circle 12 passing 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 designated as line segment ao. If a point on the virtual circle 12 that is closer to the proximal end 10a of the indwelling tube 10 than point a is designated as point x and the central angle with respect to the arc ax is 45°, then if the indwelling tube 10 intersects with the line segment ox, point a is determined to belong to the arc portion A of the indwelling tube 10, whereas if the indwelling tube 10 does not intersect with the line segment ox, 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 8, or the entire indwelling tube 10 intersects with the line segment ox, as shown in Figure 9. When the indwelling tube 10 does not intersect with the line segment ox, 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 10.

[0059] When the indwelling tube 10 has an arcuate portion A and a non-arcuate portion B, the inner cylindrical member 20 may be disposed in a section M up to a position m where the length is 50% of the longitudinal length L of the indwelling tube 10. The inner cylindrical member 20 may be disposed in the arcuate portion A of the indwelling tube 10, the non-arcuate portion B, or both the arcuate portion A and the non-arcuate portion B. As shown in Fig. 7 , the inner cylindrical member 20 is preferably disposed in at least a part of the non-arcuate portion B of the indwelling tube 10, and not in the arcuate portion A of the indwelling tube 10. This reduces the pull-out load of the inner cylindrical 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. When the in-vivo tube 10 is, for example, straight, friction between the in-vivo tube 10 and the inner tubular member 20 is small, and therefore the pull-out load of the inner tubular member 20 when the in-vivo tube 10 is placed in the affected area can be reduced.

[0060] Figure 11 is a cross-sectional view showing another embodiment of the medical device according to the present invention. The medical device 1 shown in Figure 11 includes an indwelling tube 10 and an inner cylindrical member 20. The indwelling tube 10 has a locking flap 13a on the outer surface of the proximal end of the indwelling tube 10. The indwelling tube 10 has an arcuate portion A that is curved in an arc shape and a non-arcuate portion B that is located proximally of the arcuate portion A. The arcuate portion A is configured in a closed ring shape in a plan view. This prevents the indwelling tube 10, for example, placed in the bile duct or pancreatic duct from falling out of the bile duct or pancreatic duct into the duodenum.

[0061] When the indwelling tube 10 has an arcuate portion A and a non-arcuate portion B, the inner cylindrical member 20 may be disposed in a section M up to a position m that is 50% of the longitudinal length L of the indwelling tube 10. The inner cylindrical member 20 may be disposed in the arcuate portion A of the indwelling tube 10, in the non-arcuate portion B, or in both the arcuate portion A and the non-arcuate portion B. As shown in Fig. 11 , the inner cylindrical member 20 is preferably disposed in the non-arcuate portion B of the section M of the indwelling tube 10, but not in the arcuate portion A. This reduces the pull-out load of the inner cylindrical 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.

[0062] By providing an engagement flap 13a on the outer surface of the proximal end of the in-vivo indwelling tube 10, it is possible to prevent the in-vivo indwelling tube 10, when placed in the bile duct or pancreatic duct, from entering the bile duct or pancreatic duct through the duodenal papilla, for example.

[0063] When the in-vivo tube 10 has the 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 tube 10.

[0064] 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 indwelling tube 10 and an inner cylindrical member 20. The indwelling tube 10 has an arcuate portion A that is curved in an arc shape, a non-arcuate portion B proximal to the arcuate portion A, and a proximal arcuate portion D proximal to the arcuate portion A.

[0065] When the indwelling tube 10 has an arcuate portion A, a non-arcuate portion B, and a proximal arcuate portion D, the inner cylindrical member 20 may be disposed in a section M up to a position m that is 50% of the longitudinal length L of the indwelling tube 10. The inner cylindrical member 20 may be disposed in the arcuate portion A, the non-arcuate portion B, the proximal arcuate portion D, or in a plurality of these locations of the indwelling tube 10. As shown in Fig. 12 , the inner cylindrical member 20 is preferably disposed in the region of the non-arcuate portion B of the indwelling tube 10 and in section M, but not in the arcuate portion A. This reduces the pull-out load of the inner cylindrical 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.

[0066] Furthermore, pushability can be improved by disposing the inner tube member 20 in the lumen of the proximal arc portion D. The proximal arc portion D may be disposed 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 disposed in the lumen of the proximal arc portion D.

[0067] 12 , 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.

[0068] 12 , 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 through the duodenal papilla.

[0069] FIG. 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 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.

[0070] 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 end 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 indwelling tube 10 is not disposed within the ring of the thread 60. In Figure 13, 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 when it is placed. Furthermore, the thread 60 is inserted into the through-hole 72 of the outer tubular member 50, and the loop of the thread 60 is inserted into the through-hole 71 of the indwelling tube 10, making it easier to connect the indwelling tube 10 and the outer tubular member 50 with the thread 60. Furthermore, because the thread 60 is configured as a closed loop and the inner tubular member 20 is positioned inside the loop, 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 loop. This makes it easier to place the in-vivo indwelling tube 10 in the affected area.

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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 their proximal sides. By fixing the proximal sides of the outer tube member 50 and the inner tube member 20, movement of the inner tube member 20 in the longitudinal direction may be restricted. When the outer tube member 50 is fixed at its 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. 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 outer tube member 50 may be fixed to the handle body via this.

[0075] The in-vivo indwelling tube 10 included in the medical device 1 according to the embodiment of the present invention may be used as a plastic tube stent to be placed in the bile duct or pancreatic duct, for example.

[0076] 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.

[0077] The length L of the in-vivo indwelling tube 10 in the longitudinal direction is not particularly limited, but may be, for example, 30 mm to 400 mm.

[0078] 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).

[0079] 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.

[0080] 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.

[0081] The inner cylindrical member 20 may be a single tube extending from the proximal end 20 a to the distal end 20 b, 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 20 b 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 .

[0082] 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.

[0083] 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.

[0084] 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.

[0085] 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.

[0086] 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.

[0087] 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 Japanese Patent Application No. 2023-171562 are incorporated herein by reference.

[0088] 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 Outer diameter expanded region of inner tubular member 23 Inner diameter expanded 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 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 Maximum outer diameter at section M of the tubing to be left in vivo SD2 Maximum outer diameter at section N of the tubing to be left in vivo SD3 Outer diameter at the distal end of the tubing to be left in vivo Sd1 Maximum inner diameter at section M of the tubing to be left in vivo Sd2 Inner diameter at the proximal part of section N of the tubing to be left in vivo a, b, c Point on the central axis of the tubing to be left 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 tubing to be left in vivo m1 Position where the length is 1% of the longitudinal length of the tubing to be left in vivo A Arc portion B Non-arc portion D Proximal arc portion L Length in the longitudinal direction of the tubing to be left in vivo M Section N: A section extending from the distal end of section M of the indwelling tube to the distal end of the indwelling tube.

Claims

1. A medical device comprising: a tube to be placed in a body, the 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 lumen of the tube to be placed in a lumen of the tube to be placed in a body, the distal end of the inner tubular member being disposed in a section M from the proximal end of the tube to a position which is 50% of the longitudinal length L of the tube to be placed in a body, the maximum outer diameter CD1 at the distal end of the inner tubular member being smaller than a maximum inner diameter Sd1 of the tube to be placed in the section M of the tube to be placed in a body and larger than an inner diameter Sd2 at a proximal portion of a section N of the tube to be placed in a position distal to the distal end of the section M of the tube to be placed in a body.

2. The medical device according to claim 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 claim 1, wherein a maximum outer diameter SD2 of the tube to be placed in the body at said section N of the tube to be placed in the body is smaller than a maximum outer diameter SD1 of the tube to be placed in the body at said section M of the tube to be placed in the body.

4. The medical device according to claim 1, 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 claim 1, wherein the indwelling tube has a region of reduced outer diameter at the distal end of the indwelling tube, the outer diameter of which decreases toward the distal end.

6. 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.

7. 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.

8. 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 thereof decreases toward the distal end.

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

10. 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 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 claim 1, wherein the in-vivo indwelling tube has a through hole in the side wall of the in-vivo indwelling tube.

12. 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.

13. 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.

14. The medical device according to claim 1, 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 claim 14, wherein the arcuate portion of the in-vivo indwelling tube is configured as a closed ring in a plan view.

16. The medical device according to claim 1, further comprising an outer tube member having a longitudinal direction, and a filament, 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 filament 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 filament is passed through the through hole of the indwelling tube, and the inner tube member is disposed within the ring.

Images