In-vivo indwelling implement

Abstract

Provided is an in-vivo indwelling implement (1) having a tube (10). The tube (10) includes a first section (21), a second section (22), and a third section (23) located between the first section (21) and the second section (22). A first arc portion (31) is formed in the first section (21); a second arc portion (32) is formed in the second section (22); and the third section (23) has a first end (41) and a second end (42). The tube (10) includes a first farthest point (51) that is the site in the first arc portion (31) at which the distance from a virtual straight line VL passing through the first end (41) and the second end (42) is the greatest, and includes a second farthest point (52) that is the site in the second arc portion (32) at which the distance from the virtual straight line VL is the greatest. The angle θ1 formed between a first plane passing through the first farthest point (51), the first end (41), and the second end (42) and a second plane passing through the second farthest point (52), the first end (41), and the second end (42) is 15 degrees or greater.

Description

Intravital device

[0001] The present invention relates to an in-vivo indwelling device to be placed in a living lumen such as the digestive tract.

[0002] Living lumen such as blood vessels or digestive tracts such as the bile duct and pancreatic duct may become narrowed or obstructed for various reasons. For example, when a bile duct is obstructed by a gallstone or tumor, bile may stagnate in the bile duct, potentially causing bacterial infection. Bacterial infection of bile can lead to cholangitis, and if bacteria-containing bile passes through the liver and enters the bloodstream, it may cause sepsis. In such cases, a procedure to drain bile from the bile duct is necessary. A known method for treating various diseases caused by narrowing or obstruction of a living lumen involves placing a tubular stent at the narrowed or obstructed site and expanding the narrowed or obstructed site from the inside, thereby widening the living lumen.

[0003] For example, when a stricture or blockage occurs in the bile duct, a bile duct tube stent is delivered to the stricture or blockage site. The delivered tube stent is placed at the stricture or blockage site and pushes open the stricture or blockage from the inside. By placing the tube stent, the inner diameter of the bile duct at the stricture or blockage site is expanded, improving the stricture or blockage. As a result, bile can be drained from the bile duct to the duodenum, making it possible to treat various diseases caused by stricture or blockage of the bile duct, such as biliary atresia, jaundice, and biliary tract cancer.

[0004] For example, Patent Document 1 discloses a stent kit comprising a tube stent having a stent arc portion at least one end of which is formed by at least a portion of an arc, and an inner catheter having an inner arc portion formed with the same shape as the stent arc portion and inserted into the tube stent so that the positions of the inner arc portion and the stent arc portion coincide. Patent Document 2 discloses a catheter comprising: a tube having a cylindrical wall, a first end, a second end, a first retaining feature near the first end, and a second retaining feature near the second end; a detachable portion fluidly communicating with the tube at the second end and removably attachable to the tube; an inner tube having at least one lumen, the inner tube being removably insertable into both the tube and the detachable portion; and a wire extending through at least a portion of the at least one lumen of the inner tube, a portion of the wire being attached to the tube. Patent Document 3 discloses a plastic stent characterized by comprising a shape-memory plastic tubular body having a main body at its upper and lower ends with inlet and outlet holes for the inflow and outflow of bodily fluids, a spiral upper support part at the upper part of the main body to support the body and prevent it from detaching from its installed position in the body, and a circularly wound and folded lower outlet part at the lower part of the main body. Patent Document 4 discloses a tube stent made of a flexible tubular member, comprising a substantially straight body part and a pair of tail parts, each of which has a curved shape and is connected to both ends of the body part, the pair of tail parts each having a contact part that contacts the wall of digestive tissue, and the distance between the contact parts in the axial direction of the body part is 3 cm or less.

[0005] Japanese Patent Application Laid-Open No. 2015-008862 Japanese Patent Application Laid-Open No. 2017-502818 Japanese Patent Application Laid-Open No. 2018-501824 Japanese Patent Application Laid-Open No. 2023-064797

[0006] Typically, a tube stent is delivered to a lesion by pushing the base end of the tube stent with a push shaft or by inserting an inner shaft into the lumen of the tube stent and then inserting it into an endoscope. However, with tube stents such as those described in Patent Documents 1 to 4, the curved end of the tube stent does not become completely straight even when an inner shaft is inserted into the lumen of the tube stent, making the end of the tube stent more likely to come into contact with the inner surface of the endoscope or the wall of the biological lumen. In particular, if both ends of the tube stent are curved in the same direction, the end of the tube stent becomes more strongly curled, making it more likely to come into contact with the inner surface of the endoscope or the wall of the biological lumen. As a result, both ends of the tube stent apply a large load in the same circumferential direction to the inner surface of the endoscope or the wall of the biological lumen, increasing the resistance during delivery of the tube stent and increasing the load required to insert the tube stent into the endoscope. There are also problems such as the end of the tube stent easily getting caught on the inner surface of the endoscope or the wall of the biological lumen.

[0007] The present invention has been made in view of the above circumstances, and an object of the present invention is to provide an in-vivo indwelling device that can be easily delivered.

[0008] An in-vivo indwelling device according to an embodiment of the present invention that can solve the above problems is as follows: [1] An in-vivo indwelling device having a tube, wherein the tube has a first section, a second section, and a third section located between the first and second sections in the extending direction of the tube, wherein the distal end of the in-vivo indwelling device in the longitudinal direction is included in the first section, and the proximal end of the in-vivo indwelling device in the longitudinal direction is included in the second section, wherein the tube forms a first arc section that is curved in an arc shape, and wherein the tube forms a second arc section that is curved in an arc shape, and the third section has a first end connected to the first section and a second end connected to the second section, wherein the first arc section has a first farthest point that is the point farthest from an imaginary line passing through the first and second ends, and wherein the second arc section has a second farthest point that is the point farthest from the imaginary line, The in-vivo indwelling device according to [1], wherein a first plane passing through the first most distant point, the first end, and the second end and a second plane passing through the second most distant point, the first end, and the second end form an angle of 15 degrees or more. [2] The in-vivo indwelling device according to [1], wherein a distal end of the in-vivo indwelling device is located on the first circular arc portion, and a proximal end of the in-vivo indwelling device is located on the second circular arc portion. [3] The intra-vivo indwelling device according to [1] or [2], wherein the first section has one end which is one end in the extending direction of the tube, the second section has the other end which is the other end in the extending direction of the tube, when the intra-vivo indwelling device is viewed from a direction perpendicular to the first plane, the one end is located proximal to the distal end of the intra-vivo indwelling device, and when the intra-vivo indwelling device is viewed from a direction perpendicular to the second plane, the other end is located distal to the proximal end of the intra-vivo indwelling device. [4] The intra-vivo indwelling device according to any of [1] to [3], wherein the one end is located proximal to the first end when the intra-vivo indwelling device is viewed from a direction perpendicular to the first plane, and when the intra-vivo indwelling device is viewed from a direction perpendicular to the second plane, the other end is located distal to the second end.[5] The intra-vivo indwelling device according to [1] or [2], wherein the first section has one end which is one end of the tube in the extending direction, and the second section has the other end which is the other end of the tube in the extending direction, wherein the one end constitutes the distal end of the intra-vivo indwelling device when viewed from a direction perpendicular to the first plane, and the other end constitutes the proximal end of the intra-vivo indwelling device when viewed from a direction perpendicular to the second plane. [6] The intra-vivo indwelling device according to any of [1] to [5], wherein the first section has one end which is one end of the tube in the extending direction, and the second section has the other end which is the other end of the tube in the extending direction, and wherein the intra-vivo indwelling device has a first straight line section which is located closer to the one end than the first arc section in the extending direction of the tube and is linear, and a second straight line section which is located closer to the other end than the second arc section in the extending direction of the tube. [7] The intra-vivo indwelling device according to any of [1] to [6], wherein the length from the distal end to the proximal end of the first arcuate portion in the longitudinal direction of the intra-vivo indwelling device is shorter than the length of the third section in the longitudinal direction of the intra-vivo indwelling device, and the length from the distal end to the proximal end of the second arcuate portion in the longitudinal direction of the intra-vivo indwelling device is shorter than the length of the third section in the longitudinal direction of the intra-vivo indwelling device. [8] The intra-vivo indwelling device according to any of [1] to [7], wherein the length of the first section in the longitudinal direction of the intra-vivo indwelling device is shorter than the length of the third section in the longitudinal direction of the intra-vivo indwelling device, and the length of the second section in the longitudinal direction of the intra-vivo indwelling device is shorter than the length of the third section in the longitudinal direction of the intra-vivo indwelling device. [9] The intra-vivo indwelling device according to any of [1] to [8], wherein the radius of curvature of the first arcuate portion is 80% or more and 120% or less of the radius of curvature of the second arcuate portion.

[0009] According to the in-vivo indwelling device of the present invention, the angle formed by the first plane passing through the first most distant point, which is the point on the first arcuate portion furthest from the imaginary line, the first end, and the second end, and the second plane passing through the second most distant point, which is the point on the second arcuate portion furthest from the imaginary line, the first end, and the second end, is 15 degrees or more, so that the first arcuate portion and the second arcuate portion exist on different planes. Therefore, when delivering the in-vivo indwelling device, contact between both ends of the in-vivo indwelling device and the inner surface of the endoscope, the lumen wall of the biological lumen, etc. can be made in different directions in the circumferential direction of the lumen. As a result, the load applied to both ends of the in-vivo indwelling device can be distributed, improving the insertability of the in-vivo indwelling device and facilitating delivery of the in-vivo indwelling device.

[0010] Fig. 1 shows a view of the in-vivo indwelling device according to one embodiment of the present invention, viewed from a direction perpendicular to a first plane. Fig. 2 shows a view of the in-vivo indwelling device shown in Fig. 1, viewed from a direction perpendicular to a second plane. Fig. 3 shows a view of the in-vivo indwelling device shown in Fig. 1, viewed from a longitudinal direction. Fig. 4 shows a view of the in-vivo indwelling device according to another embodiment of the present invention, viewed from a direction perpendicular to the first plane. Fig. 5 shows a view of the in-vivo indwelling device shown in Fig. 4, viewed from a direction perpendicular to the second plane. Fig. 6 shows a view of the in-vivo indwelling device shown in Fig. 4, viewed from a longitudinal direction.

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

[0012] Fig. 1 is a view of an intracorporeal indwelling device 1 according to an embodiment of the present invention, viewed from a direction perpendicular to a first plane 61, Fig. 2 is a view of the intracorporeal indwelling device 1 viewed from a direction perpendicular to a second plane 62, and Fig. 3 is a view of the intracorporeal indwelling device 1 viewed from the longitudinal direction x. Fig. 4 is a view of an intracorporeal indwelling device 1 according to another embodiment of the present invention, viewed from a direction perpendicular to the first plane 61, Fig. 5 is a view of the intracorporeal indwelling device 1 viewed from a direction perpendicular to the second plane 62, and Fig. 6 is a view of the intracorporeal indwelling device 1 viewed from the longitudinal direction x. As shown in Figs. 1 to 6, the intracorporeal indwelling device 1 has a tube 10.

[0013] In the present invention, the proximal side refers to the side closer to the user in the longitudinal direction x of the in-vivo indwelling device 1, and the distal side refers to the side opposite the proximal side, i.e., the side where treatment is performed by the in-vivo indwelling device 1 (the side of the lesion). The longitudinal direction x of the in-vivo indwelling device 1 can also be referred to as the longitudinal direction of the in-vivo indwelling device 1. The longitudinal direction x of the in-vivo indwelling device 1 can also be referred to as the longitudinal direction x of the tube 10, and the longitudinal direction of the in-vivo indwelling device 1 can also be referred to as the longitudinal direction of the tube 10. Furthermore, when each member or part is divided into two equal parts in the longitudinal direction x of the tube 10, the part of each member or part located on the distal side is referred to as the distal part of each member or part, and the part of each member or part located on the proximal side is referred to as the proximal part of each member or part. The distal end of each member or part is the end located most distally of each member or part. The proximal end of each member or part is the end of the member or part that is located closest to the other. The end includes the peripheral portion of the end. That is, the distal end refers to the distal end and the peripheral portion of the distal end, and the proximal end refers to the proximal end and the peripheral portion of the proximal end.

[0014] Furthermore, a radial direction y and a circumferential direction z are defined as directions orthogonal to the longitudinal direction x. The radial direction y is a direction perpendicular to the longitudinal direction x, and is a direction connecting the centroid of the outer edge of the tube 10 and a point on the outer edge in a cross section perpendicular to the longitudinal direction x. The circumferential direction z is a direction along the outer edge of the tube 10 in a cross section perpendicular to the longitudinal direction x.

[0015] The tube 10 of the in-vivo indwelling device 1 is preferably a long object having an inner lumen and one end and the other end. Examples of the in-vivo indwelling device 1 include a stent, an occluder, etc. Among these, the in-vivo indwelling device 1 is preferably a plastic stent.

[0016] Examples of materials that can be used to form the tube 10 include polyamide resins, polyester resins, polyurethane resins, polyolefin resins, fluorine-based resins, vinyl chloride resins, silicone resins, and natural rubber. These materials may be used alone or in combination. Among these, the resin that forms the tube 10 is preferably at least one of polyamide resins, polyester resins, polyurethane resins, polyolefin resins, and fluorine-based resins. By using at least one of polyamide resins, polyester resins, polyurethane resins, polyolefin resins, and fluorine-based resins as the material for the tube 10, the slipperiness of the surface of the tube 10 can be increased, thereby improving insertability into a biological lumen. The tube 10 can be manufactured using conventional methods such as extrusion molding and injection molding.

[0017] 1, 2, 4, and 5, the tube 10 has a first section 21, a second section 22, and a third section 23 located between the first section 21 and the second section 22 in the extending direction of the tube 10, and the distal end 1d of the in-vivo indwelling device 1 in the longitudinal direction x is included in the first section 21, and the proximal end 1p of the in-vivo indwelling device 1 in the longitudinal direction x is included in the second section 22. In other words, the tube 10 has the following sections in order from the proximal side to the distal side of the tube 10: the second section 22, the third section 23, and the first section 21.

[0018] Although not shown, the tube 10 may further have a section different from the first section 21, the second section 22, and the third section 23. Specifically, in the extension direction of the tube 10, a section different from the first section 21, the second section 22, and the third section 23 may be provided on the side opposite to the side on which the third section 23 of the first section 21 is provided, and a section different from the first section 21, the second section 22, and the third section 23 may be provided on the side opposite to the side on which the third section 23 is provided of the second section 22.

[0019] 1 , 2 , 4 , and 5 , in the first section 21, the tube 10 forms a first arc portion 31 that is curved in an arc shape. The first arc portion 31 refers to the portion of the tube 10 that is curved in an arc shape in the first section 21 when no external force other than gravity is applied to the tube 10. The first arc portion 31 may be formed by the entire tube 10 in the first section 21, or may be formed by a portion of the tube 10 in the first section 21. In other words, the first arc portion 31 is formed by at least a portion of the tube 10 located in the first section 21.

[0020] In the second section 22, the tube 10 forms a second arc portion 32 that is curved in an arc shape. The second arc portion 32 refers to the portion of the tube 10 that is curved in an arc shape in the second section 22 when no external force other than gravity is applied to the tube 10. The second arc portion 32 may be formed by the entire tube 10 in the second section 22, or may be formed by a portion of the tube 10 in the second section 22. In other words, the second arc portion 32 is formed by at least a portion of the tube 10 located in the second section 22.

[0021] The first arcuate portion 31 and the second arcuate portion 32 have the function of contacting the biological lumen and fixing the biological lumen to the biological lumen. Specifically, for example, if the biological indwelling device 1 is a bile duct stent, the first arcuate portion 31 may be positioned distal to a narrowed portion (obstructed portion) of the bile duct to prevent the biological indwelling device 1 from falling out from the bile duct toward the duodenum, and the second arcuate portion 32 may be positioned near the duodenal papilla to prevent the biological indwelling device 1 from getting lost in the bile duct.

[0022] The shapes of the first arc portion 31 and the second arc portion 32 may be unclosed arc shapes as shown in Figures 1 and 2, or may be closed circular shapes as shown in Figures 4 and 5. Examples of unclosed arc shapes include semicircular shapes. If the first arc portion 31 and the second arc portion 32 are unclosed arc shapes, the in-vivo indwelling device 1 can be easily inserted into a biological lumen or the like. Furthermore, if the first arc portion 31 and the second arc portion 32 are closed circular shapes, the effect of fixing the in-vivo indwelling device 1 in a predetermined position can be improved.

[0023] The shape of the first arc portion 31 may be the same as or different from the shape of the second arc portion 32. Specifically, as shown in Figures 1 and 2, both the first arc portion 31 and the second arc portion 32 may be arc-shaped, which are not closed circles, or as shown in Figures 4 and 5, both the first arc portion 31 and the second arc portion 32 may be closed circles, or, although not shown, one of the first arc portion 31 and the second arc portion 32 may be arc-shaped, which are not closed circles, and the other may be closed circles.

[0024] 1, 2, 4, and 5, the third section 23 has a first end 41 connected to the first section 21 and a second end 42 connected to the second section 22. In other words, in the extension direction of the tube 10, the end of the third section 23 on the first section 21 side is the first end 41, and the end of the third section 23 on the second section 22 side is the second end 42.

[0025] It is preferable that the tube 10 is linear in the third section 23. That is, it is preferable that the tube 10 does not have an arc-shaped portion in the third section 23. By making the tube 10 linear in the third section 23, when the in-vivo indwelling device 1 is placed in a biological lumen, the in-vivo indwelling device 1 can easily conform to the biological lumen and is less likely to impose a large load on portions other than the narrowed or obstructed portion, thereby improving the minimally invasive nature of the in-vivo indwelling device 1.

[0026] 1 and 4 , the intra-vivo indwelling device 1 has a first farthest point 51, which is the point on the first arcuate portion 31 that is farthest from the imaginary line VL passing through the first end 41 and the second end 42. One method for determining the first farthest point 51 is to take a photograph of the intra-vivo indwelling device 1 with the first arcuate portion 31 of the intra-vivo indwelling device 1 placed so that no external forces other than gravity are applied to the intra-vivo indwelling device 1, measure the shortest distance between the imaginary line VL and a point on the first arcuate portion 31 in the obtained image, and determine the point with the longest shortest distance from the imaginary line VL as the first farthest point 51. When determining the first farthest point 51, it is preferable to take a photograph of the intra-vivo indwelling device 1 in a field of view where the length of the first arcuate portion 31 of the tube 10 in the extension direction is the longest, measure the distance, and determine the first farthest point 51.

[0027] 2 and 5 , the in-vivo indwelling device 1 has a second farthest point 52, which is the point on the second arcuate portion 32 that is farthest from the imaginary line VL passing through the first end 41 and the second end 42. One method for determining the second farthest point 52 is to take a photograph of the in-vivo indwelling device 1 with the second arcuate portion 32 of the in-vivo indwelling device 1 placed so that no external forces other than gravity are applied to the in-vivo indwelling device 1, measure the shortest distance between the imaginary line VL and a point on the second arcuate portion 32 in the obtained image, and determine the point with the longest shortest distance from the imaginary line VL as the second farthest point 52. When determining the second farthest point 52, it is preferable to take a photograph of the in-vivo indwelling device 1 in a field of view where the length of the second arcuate portion 32 of the tube 10 in the extension direction is longest, and measure the distance to determine the second farthest point 52.

[0028] 3 and 6 , the angle θ1 formed between a first plane 61 passing through the first farthest point 51, the first end 41, and the second end 42 and a second plane 62 passing through the second farthest point 52, the first end 41, and the second end 42 is 15 degrees or greater. The angle θ1 formed between the first plane 61 and the second plane 62 refers to the smaller angle between the virtual straight line VL and a portion of the first plane 61 on the side where the first farthest point 51 is located, with the intersection line between the first plane 61 and the second plane 62 as the boundary, and a portion of the second plane 62 on the side where the second farthest point 52 is located, with the intersection line as the boundary. The angle θ1 formed between the first plane 61 and the second plane 62 is measured when no external force other than gravity is applied to the tube 10.

[0029] When the angle θ1 between the first plane 61 and the second plane 62 is 15 degrees or greater, the first arcuate portion 31 included in the first plane 61 and the second arcuate portion 32 included in the second plane 62 exist in different planes. When the first arcuate portion 31 and the second arcuate portion 32 exist in different planes, when the in-vivo indwelling device 1 is delivered, the contact between the inner surface of the endoscope, the wall of the biological lumen, etc. and both ends of the in-vivo indwelling device 1 can be made in different directions in the circumferential direction of the lumen of the endoscope, etc. As a result, the load applied to both ends of the in-vivo indwelling device 1 during delivery can be distributed, improving the insertability of the in-vivo indwelling device 1 and facilitating delivery.

[0030] The angle θ1 formed between the first plane 61 and the second plane 62 is preferably 20 degrees or greater, more preferably 25 degrees or greater, even more preferably 30 degrees or greater, even more preferably 35 degrees or greater, particularly preferably 40 degrees or greater, and most preferably 45 degrees or greater. By setting the lower limit of the angle θ1 formed between the first plane 61 and the second plane 62 within the above range, it becomes easier to shift the positional relationship between the first arc-shaped portion 31 included in the first plane 61 and the second arc-shaped portion 32 included in the second plane 62 in the circumferential direction z, and the tube 10 is less likely to develop a large curl throughout the entire in-vivo indwelling device 1. As a result, both ends of the in-vivo indwelling device 1 are less likely to get caught on the inner surface of an endoscope, the wall of a biological lumen, or the like during delivery of the in-vivo indwelling device 1. Furthermore, the angle θ1 formed between the first plane 61 and the second plane 62 is preferably 165 degrees or less, more preferably 160 degrees or less, even more preferably 155 degrees or less, even more preferably 150 degrees or less, particularly preferably 145 degrees or less, and most preferably 140 degrees or less. By setting the upper limit of the angle θ1 formed between the first plane 61 and the second plane 62 within the above range, the overall outer shape of the in-vivo indwelling device 1 in a cross section perpendicular to the longitudinal direction x of the in-vivo indwelling device 1 can be made small when the in-vivo indwelling device 1 is inserted into an endoscope or a biological lumen. This makes it possible to provide an in-vivo indwelling device 1 that is easy to deliver and has good insertability.

[0031] 1 and 2, it is preferable that the distal end 1d of the in-vivo indwelling device 1 is located at the first arcuate portion 31, and the proximal end 1p of the in-vivo indwelling device 1 is located at the second arcuate portion 32. That is, it is preferable that the distal end 1d of the in-vivo indwelling device 1 is the end of the first arcuate portion 31 in the longitudinal direction x of the tube 10, and the proximal end 1p of the in-vivo indwelling device 1 is the end of the second arcuate portion 32 in the longitudinal direction x of the tube 10. By having the distal end 1d of the in-vivo indwelling device 1 located at the first arcuate portion 31 and the proximal end 1p of the in-vivo indwelling device 1 located at the second arcuate portion 32, arcuate portions exist at the distal end and proximal end of the in-vivo indwelling device 1, and even if the distal end 1d or the proximal end 1p of the in-vivo indwelling device 1 comes into contact with the wall of a biological lumen after placement, the wall is less likely to be damaged.

[0032] As shown in Fig. 1, when the intra-vivo indwelling device 1 is viewed from a direction perpendicular to the first plane 61, the first most distant point 51 is located proximal to the distal end 1d of the intra-vivo indwelling device 1, and as shown in Fig. 2, when the intra-vivo indwelling device 1 is viewed from a direction perpendicular to the second plane 62, the second most distant point 52 is preferably located distal to the proximal end 1p of the intra-vivo indwelling device 1. By having the first most distant point 51 located proximal to the distal end 1d and the second most distant point 52 located distal to the proximal end 1p, the curved portions of the first arcuate portion 31 and the second arcuate portion 32 are located at the distal end portion including the distal end 1d and the proximal end portion including the proximal end 1p of the intra-vivo indwelling device 1. As a result, the degree of curvature of the first arcuate portion 31 and the second arcuate portion 32 increases, which can more easily improve the effect of preventing displacement or falling off of the in-vivo indwelling device 1 when it is placed.

[0033] As shown in Fig. 1 , when the in-vivo indwelling device 1 is viewed from a direction perpendicular to the first plane 61, one end 71, which is one end of the tube 10 in the extending direction, does not coincide with the distal end 1d of the in-vivo indwelling device 1. Also, as shown in Fig. 2 , when the in-vivo indwelling device 1 is viewed from a direction perpendicular to the second plane 62, the other end 72, which is the other end of the tube 10 in the extending direction, does not preferably coincide with the proximal end 1p of the in-vivo indwelling device 1. Since the one end 71 and the distal end 1d do not coincide, and the other end 72 and the proximal end 1p do not coincide, the one end 71 and the other end 72 of the tube 10 do not exist at the distal end 1d and the proximal end 1p of the in-vivo indwelling device 1, and the one end 71 and the other end 72 of the in-vivo indwelling device 1 are less likely to come into contact with the wall of the biological lumen after placement. As a result, the in-vivo indwelling device 1 is less likely to damage the wall of the biological lumen.

[0034] As shown in FIGS. 1 and 2 , the first section 21 has one end 71 which is one end in the extension direction of the tube 10, and the second section 22 has the other end 72 which is the other end in the extension direction of the tube 10. When the intracorporeal indwelling device 1 is viewed from a direction perpendicular to the first plane 61, the one end 71 is located proximal to the distal end 1d of the intracorporeal indwelling device 1, and when the intracorporeal indwelling device 1 is viewed from a direction perpendicular to the second plane 62, the other end 72 is preferably located distal to the proximal end 1p of the intracorporeal indwelling device 1. Because one end 71 is located proximal to the distal end 1d of the in-vivo indwelling device 1 and the other end 72 is located distal to the proximal end 1p of the in-vivo indwelling device 1, one end 71 of the tube 10 is not present at the distal end, including the distal end 1d, of the in-vivo indwelling device 1, but the curved portion of the first arcuate portion 31 is located there, and the other end 72 of the tube 10 is not present at the proximal end, including the proximal end 1p, but the curved portion of the second arcuate portion 32 is located there. This further enhances the effect of preventing one end 71 and the other end 72 of the tube 10 from getting caught on the inner surface of the endoscope or the wall of the biological lumen when transporting the in-vivo indwelling device 1, making it easier to transport the in-vivo indwelling device 1. Furthermore, because one end 71 and the other end 72 of the in-vivo indwelling device 1 are less likely to come into contact with the wall of the biological lumen after placement, it is less likely to damage the wall of the biological lumen, etc. Furthermore, by increasing the curvature of the first arcuate portion 31 and the second arcuate portion 32, it is possible to improve the effect of preventing the in-vivo indwelling device 1 from shifting or falling off after placement.

[0035] As shown in Fig. 1, when the in-vivo indwelling device 1 is viewed in a direction perpendicular to the first plane 61, one end 71 is located proximal to the first end 41, and as shown in Fig. 2, when the in-vivo indwelling device 1 is viewed in a direction perpendicular to the second plane 62, the other end 72 is preferably located distal to the second end 42. By having one end 71 located proximal to the first end 41 and the other end 72 located distal to the second end 42, the magnitude of curvature of the first arcuate portion 31 and the second arcuate portion 32 can be increased. As a result, the effect of preventing displacement or detachment of the in-vivo indwelling device 1 when it is placed can be improved.

[0036] As shown in Fig. 1 , when the intracorporeal indwelling device 1 is viewed from a direction perpendicular to the first plane 61, the first most distant point 51 is located distal to one end 71, and as shown in Fig. 2 , when the intracorporeal indwelling device 1 is viewed from a direction perpendicular to the second plane 62, the second most distant point 52 is preferably located proximal to the other end 72. By having the first most distant point 51 located distal to one end 71 and the second most distant point 52 located proximal to the other end 72, one end 71 and the other end 72 are configured to approach the third section 23. As a result, when the intracorporeal indwelling device 1 is transported, the one end 71 and the other end 72 are less likely to come into contact with and get caught on the inner surface of the endoscope or the wall of the biological lumen, making it easier to transport the intracorporeal indwelling device 1 smoothly. Furthermore, since one end 71 and the other end 72 of the in-vivo indwelling device 1 are less likely to come into contact with the wall of the biological lumen after placement, it is possible to prevent damage to the wall of the biological lumen, etc. Furthermore, the curvature of the first arcuate portion 31 and the second arcuate portion 32 can be made larger, making it possible to prevent the in-vivo indwelling device 1 from shifting position or falling off after placement.

[0037] 4, when the intra-vivo indwelling device 1 is viewed from a direction perpendicular to the first plane 61, one end 71 preferably constitutes the distal end 1d of the intra-vivo indwelling device 1, and when the intra-vivo indwelling device 1 is viewed from a direction perpendicular to the second plane 62, the other end 72 preferably constitutes the proximal end 1p of the intra-vivo indwelling device 1. In other words, when the intra-vivo indwelling device 1 is viewed from a direction perpendicular to the first plane 61, one end 71 preferably coincides with the distal end 1d of the intra-vivo indwelling device 1, and when the intra-vivo indwelling device 1 is viewed from a direction perpendicular to the second plane 62, the other end 72 preferably coincides with the proximal end 1p of the intra-vivo indwelling device 1. One end 71 constitutes the distal end 1d, and the other end 72 constitutes the proximal end 1p. Therefore, when the in-vivo indwelling device 1 is placed, for example, from the bile duct to the duodenum, the drainage effect is improved at one end 71, which constitutes the distal end 1d of the in-vivo indwelling device 1, and the effect of preventing the reflux of food residue and the like can be improved at the other end 72, which constitutes the proximal end 1p of the in-vivo indwelling device 1.

[0038] 4 and 5 , the tube 10 preferably has a first straight section 81 that is linear and located closer to the one end 71 than the first arcuate section 31 in the extension direction of the tube 10, and a second straight section 82 that is linear and located closer to the other end 72 than the second arcuate section 32. By having the first straight section 81 and the second straight section 82, the first straight section 81 is located closer to the one end 71 than the first arcuate section 31, and the second straight section 82 is located closer to the other end 72 than the second arcuate section 32, resulting in a configuration in which both ends of the biological indwelling device 1 have linear sections. As a result, the first straight section 81 makes it easy to insert a guidewire or the like into the biological indwelling device 1, and the second straight section 82 makes it easier to transmit a pushing force from the proximal side to the distal side to the distal end of the biological indwelling device 1 when delivering the biological indwelling device 1.

[0039] 4 and 5, it is also preferable that the distal end 1d of the intracorporeal indwelling device 1 is located in the first straight section 81, and the proximal end 1p of the intracorporeal indwelling device 1 is located in the second straight section 82. By having the distal end 1d located in the first straight section 81 and the proximal end 1p located in the second straight section 82, the intracorporeal indwelling device 1 has linear sections at the distal end including the distal end 1d and the proximal end including the proximal end 1p. This makes it easier to insert a guidewire or the like into the intracorporeal indwelling device 1, and also makes it easier to transmit force applied from the proximal side of the intracorporeal indwelling device 1 to the tip.

[0040] 4 and 5 , it is preferable that the length L31 from the distal end 31d to the proximal end 31p of the first arcuate portion 31 in the longitudinal direction x of the in-vivo indwelling device 1 is shorter than the length L23 of the third section 23 in the longitudinal direction x of the in-vivo indwelling device 1, and the length L32 from the distal end 32d to the proximal end 32p of the second arcuate portion 32 in the longitudinal direction x of the in-vivo indwelling device 1 is shorter than the length L23 of the third section 23 in the longitudinal direction x of the in-vivo indwelling device 1. In other words, it is preferable that the length L23 of the third section 23 in the longitudinal direction x of the in-vivo indwelling device 1 is longer than the length L31 from the distal end 31d to the proximal end 31p of the first arcuate portion 31 and the length L32 from the distal end 32d to the proximal end 32p of the second arcuate portion 32 in the longitudinal direction x of the in-vivo indwelling device 1. Because the length L31 of the first arcuate portion 31 and the length L32 of the second arcuate portion 32 are shorter than the length L23 of the third section 23, the size of the first arcuate portion 31 and the second arcuate portion 32, which are curved in an arc shape, can be made smaller compared to the length L23 of the third section 23 of the tube 10. As a result, when the in-vivo indwelling device 1 is delivered and inserted into the channel of the endoscope, the load applied by the first arcuate portion 31 and the second arcuate portion 32 coming into contact with the inner surface of the endoscope is easily reduced, allowing the in-vivo indwelling device 1 to be inserted smoothly.

[0041] 1, 2, 4, and 5, it is preferable that the length L21 of the first section 21 in the longitudinal direction x of the intra-vivo indwelling device 1 is shorter than the length L23 of the third section 23 in the longitudinal direction x of the intra-vivo indwelling device 1, and that the length L22 of the second section 22 in the longitudinal direction x of the intra-vivo indwelling device 1 is shorter than the length L23 of the third section 23 in the longitudinal direction x of the intra-vivo indwelling device 1. In other words, it is preferable that the length L23 of the third section 23 in the longitudinal direction x of the intra-vivo indwelling device 1 is longer than the length L21 of the first section 21 and the length L22 of the second section 22 in the longitudinal direction x of the intra-vivo indwelling device 1. Because the length L21 of the first section 21 and the length L22 of the second section 22 are shorter than the length L23 of the third section 23, the length L21 of the first section 21 in which the first arc portion 31 is disposed and the length L22 of the second section 22 in which the second arc portion 32 is disposed can be made shorter than the length L23 of the third section 23 of the tube 10, and a configuration can be achieved in which both ends of the in-vivo retention device 1 are less likely to get caught on the inner surface of the endoscope or the luminal wall of the biological lumen when the in-vivo retention device 1 is delivered.

[0042] As shown in Figures 4 and 5, it is preferable that the length L31 from the distal end 31d to the proximal end 31p of the first arcuate portion 31 in the longitudinal direction x of the intra-vivo indwelling device 1 is shorter than the length L21 of the first section 21 in the longitudinal direction x of the intra-vivo indwelling device 1, and the length L32 from the distal end 32d to the proximal end 32p of the second arcuate portion 32 in the longitudinal direction x of the intra-vivo indwelling device 1 is shorter than the length L22 of the second section 22 in the longitudinal direction x of the intra-vivo indwelling device 1. Because the length L31 of the first arcuate portion 31 is shorter than the length L21 of the first section 21 and the length L32 of the second arcuate portion 32 is shorter than the length L22 of the second section 22, the in-vivo indwelling device 1 has a portion of the tube 10 extending linearly toward one end 71 from the first arcuate portion 31, and a portion of the tube 10 extending linearly toward the other end 72 from the second arcuate portion 32. As a result, the distal end and proximal end of the in-vivo indwelling device 1 are linear, making it possible for both ends of the in-vivo indwelling device 1 to be less likely to get caught on the inner surface of an endoscope or the luminal wall of a biological lumen.

[0043] The length of the first arc portion 31 in the extension direction of the tube 10 affects the likelihood of contact between the first arc portion 31 and the inner surface of the endoscope, the wall of a biological lumen, etc. Similarly, the length of the second arc portion 32 in the extension direction of the tube 10 affects the likelihood of contact between the second arc portion 32 and the inner surface of the endoscope, the wall of a biological lumen, etc. When the ratio of the total length of the arc portions, which is the sum of the lengths of the first arc portion 31 and the second arc portion 32 in the extension direction of the tube 10, to the length of the tube 10 in the extension direction of the tube 10 is small, it is possible to make it less likely that the first arc portion 31 and the second arc portion 32 will come into contact with the inner surface of the endoscope, the wall of a biological lumen, etc.

[0044] The length of the arc portion is defined as the total length of the arc portion obtained by adding the length of the first arc portion 31 and the length of the second arc portion 32 in the extension direction of the tube 10 (the length of the first arc portion 31 + the length of the second arc portion 32), and the length of the non-arc portion is defined as the length of the tube 10 in the extension direction minus the length of the arc portion (the length of the tube 10 - (the length of the first arc portion 31 + the length of the second arc portion 32)). When the ratio of the length of the non-arc portion to the length of the arc portion (the length of the non-arc portion / the length of the arc portion) exceeds 12, it is preferable that the angle θ1 between the first plane 61 and the second plane 62 is 15 degrees or greater. The non-arc portion is the portion of the tube 10 excluding the first arc portion 31 and the second arc portion 32, and refers to the portion that is not curved in an arc shape when no external force other than gravity is applied to the tube 10. When the ratio of the length of the non-arc portion to the length of the arc portion is 3 or more and 12 or less, the angle θ1 formed between the first plane 61 and the second plane 62 is preferably 20 degrees or more, more preferably 25 degrees or more, even more preferably 30 degrees or more, even more preferably 35 degrees or more, particularly preferably 40 degrees or more, and most preferably 45 degrees or more. When the ratio of the length of the non-arc portion to the length of the arc portion is less than 3, the angle θ1 formed between the first plane 61 and the second plane 62 is preferably 30 degrees or more, more preferably 35 degrees or more, even more preferably 40 degrees or more, and particularly preferably 45 degrees or more.

[0045] The longer the length of the non-arcuate portion in the extension direction of the tube 10, the less likely both ends of the in-vivo indwelling device 1 will come into contact with the inner surface of the endoscope, the wall of the biological lumen, etc. When the length of the non-arcuate portion exceeds 150 mm, the angle θ1 between the first plane 61 and the second plane 62 is preferably 15 degrees or greater. When the length of the non-arcuate portion is 40 mm or greater and 150 mm or less, the angle θ1 between the first plane 61 and the second plane 62 is preferably 20 degrees or greater, more preferably 25 degrees or greater, even more preferably 30 degrees or greater, even more preferably 35 degrees or greater, particularly preferably 40 degrees or greater, and most preferably 45 degrees or greater. When the length of the non-arcuate portion is less than 40 mm, the angle θ1 between the first plane 61 and the second plane 62 is preferably 30 degrees or greater, more preferably 35 degrees or greater, even more preferably 40 degrees or greater, and particularly preferably 45 degrees or greater.

[0046] 4 and 5 , the radius of curvature r31 of the first arc-shaped portion 31 is preferably 80% or more and 120% or less of the radius of curvature r32 of the second arc-shaped portion 32. The radius of curvature r31 of the first arc-shaped portion 31 refers to the smallest radius of curvature of the portion of the tube 10 in the first arc-shaped portion 31 where the tube 10 is curved in an arc shape when the in-vivo indwelling device 1 is viewed from a direction perpendicular to the first plane 61. Similarly, the radius of curvature r32 of the second arc-shaped portion 32 refers to the smallest radius of curvature of the portion of the tube 10 in the second arc-shaped portion 32 where the tube 10 is curved in an arc shape when the in-vivo indwelling device 1 is viewed from a direction perpendicular to the second plane 62. When the radius of curvature r31 of the first arc-shaped portion 31 is 80% or more and 120% or less of the radius of curvature r32 of the second arc-shaped portion 32, the degrees of curvature of the first arc-shaped portion 31 and the second arc-shaped portion 32 become similar. As a result, when delivering the intracorporeal indwelling device 1, the loads applied to both ends of the intracorporeal indwelling device 1 can be made to be approximately the same, making it easier to deliver the intracorporeal indwelling device 1.

[0047] A method for measuring the radius of curvature r31 of the first arc portion 31 includes, for example, placing the tube 10 in the first arc portion 31 in a state where no external force other than gravity is applied to the tube 10, taking a photograph of the first arc portion 31, and measuring the minimum radius of curvature r31 of the first arc portion 31 in the obtained image. Similarly, a method for measuring the radius of curvature r32 of the second arc portion 32 includes, for example, placing the tube 10 in the second arc portion 32 in a state where no external force other than gravity is applied to the tube 10, taking a photograph of the second arc portion 32, and measuring the minimum radius of curvature r32 of the second arc portion 32 in the obtained image.

[0048] The radius of curvature r31 of the first arc-shaped portion 31 is preferably 80% or more of the radius of curvature r32 of the second arc-shaped portion 32, more preferably 85% or more, even more preferably 90% or more, and even more preferably 95% or more. The radius of curvature r31 of the first arc-shaped portion 31 is preferably 120% or less of the radius of curvature r32 of the second arc-shaped portion 32, more preferably 115% or less, even more preferably 110% or less, and even more preferably 105% or less. By setting the lower and upper limits of the ratio of the radius of curvature r31 of the first arc-shaped portion 31 to the radius of curvature r32 of the second arc-shaped portion 32 within the above ranges, the degree of curvature of the first arc-shaped portion 31 and the degree of curvature of the second arc-shaped portion 32 become approximately the same.

[0049] The curvature radius r31 of the first arc-shaped portion 31 and the curvature radius r32 of the second arc-shaped portion 32 affect the likelihood of contact between the first arc-shaped portion 31 and the second arc-shaped portion 32 and the inner surface of the endoscope, the wall of the biological lumen, etc. When the curvature radius r31 of the first arc-shaped portion 31 or the curvature radius r32 of the second arc-shaped portion 32 is large, the in-vivo indwelling device 1 is more likely to conform to the endoscope and the biological lumen and is less likely to come into contact with the inner surface of the endoscope, the wall of the biological lumen, etc., compared to when the respective curvature radii are small. When at least one of the curvature radius r31 of the first arc-shaped portion 31 and the curvature radius r32 of the second arc-shaped portion 32 exceeds 13 mm, the angle θ1 between the first plane 61 and the second plane 62 is preferably 15 degrees or greater. When at least one of the curvature radius r31 of the first arc portion 31 and the curvature radius r32 of the second arc portion 32 is 5 mm or more and 13 mm or less, the angle θ1 between the first plane 61 and the second plane 62 is preferably 20 degrees or more, more preferably 25 degrees or more, even more preferably 30 degrees or more, even more preferably 35 degrees or more, particularly preferably 40 degrees or more, and most preferably 45 degrees or more. When at least one of the curvature radius r31 of the first arc portion 31 and the curvature radius r32 of the second arc portion 32 is less than 5 mm, the angle θ1 is preferably 30 degrees or more, more preferably 35 degrees or more, even more preferably 40 degrees or more, and particularly preferably 45 degrees or more.

[0050] This application claims the benefit of priority based on Japanese Patent Application No. 2024-025852, filed on February 22, 2024. The entire contents of the specification of Japanese Patent Application No. 2024-025852, filed on February 22, 2024, are incorporated herein by reference.

[0051] 1: In-vivo indwelling device 1d: Distal end of in-vivo indwelling device 1p: Proximal end of in-vivo indwelling device 10: Tube 21: First section 22: Second section 23: Third section 31: First arcuate portion 31d: Distal end of first arcuate portion 31p: Proximal end of first arcuate portion 32: Second arcuate portion 32d: Distal end of second arcuate portion 32p: Proximal end of second arcuate portion 41: First end 42: Second end 51: First farthest point 52: Second farthest point 61: First plane 62: Second plane 71: One end 72: Other end 81: First straight line section 82: Second straight line section VL: Virtual line θ1: Angle between the first plane and the second plane L21: Length of first section L22: Length of second section L23: Length of the third section L31: Length from the distal end to the proximal end of the first arcuate portion L32: Length from the distal end to the proximal end of the second arcuate portion r31: Radius of curvature of the first arcuate portion r32: Radius of curvature of the second arcuate portion x: Longitudinal direction y: Radial direction z: Circumferential direction

Claims

1. An in-vivo indwelling device having a tube, wherein the tube has a first section, a second section, and a third section located between the first and second sections in the extending direction of the tube, wherein the distal end of the in-vivo indwelling device in the longitudinal direction is included in the first section, and the proximal end of the in-vivo indwelling device in the longitudinal direction is included in the second section, wherein the tube in the first section forms a first arc section that is curved in an arc, and wherein the tube in the second section forms a second arc section that is curved in an arc, and wherein the third section has a first end connected to the first section and a second end connected to the second section, wherein the first arc section has a first farthest point that is the point farthest from an imaginary line passing through the first and second ends, and wherein the second arc section has a second farthest point that is the point farthest from the imaginary line, an angle formed by a first plane passing through the first most distant point, the first end, and the second end and a second plane passing through the second most distant point, the first end, and the second end is 15 degrees or greater.

2. The in-vivo indwelling device according to claim 1, wherein the distal end of the in-vivo indwelling device is located at the first arcuate portion, and the proximal end of the in-vivo indwelling device is located at the second arcuate portion.

3. The intra-vivo indwelling device according to claim 2, wherein the first section has one end which is one end of the tube in the extending direction, the second section has the other end which is the other end of the tube in the extending direction, when the intra-vivo indwelling device is viewed from a direction perpendicular to the first plane, the one end is located proximal to the distal end of the intra-vivo indwelling device, and when the intra-vivo indwelling device is viewed from a direction perpendicular to the second plane, the other end is located distal to the proximal end of the intra-vivo indwelling device.

4. The intracorporeal device according to claim 3, wherein, when the intracorporeal device is viewed from a direction perpendicular to the first plane, the one end is located proximal to the first end, and when the intracorporeal device is viewed from a direction perpendicular to the second plane, the other end is located distal to the second end.

5. The intra-vivo indwelling device according to claim 1, wherein the first section has one end which is one end of the tube in the extending direction, the second section has the other end which is the other end of the tube in the extending direction, the one end constitutes the distal end of the intra-vivo indwelling device when viewed from a direction perpendicular to the first plane, and the other end constitutes the proximal end of the intra-vivo indwelling device when viewed from a direction perpendicular to the second plane.

6. An in-vivo indwelling device according to any one of claims 1 to 5, wherein the first section has one end which is one end of the tube in the extending direction, and the second section has the other end which is the other end of the tube in the extending direction, and wherein the in-vivo indwelling device has a first straight section which is located closer to the one end than the first arc section in the extending direction of the tube and is straight, and a second straight section which is located closer to the other end than the second arc section in the extending direction of the tube.

7. The intra-vivo retention device according to claim 1, wherein the length from the distal end to the proximal end of the first arcuate portion in the longitudinal direction of the intra-vivo retention device is shorter than the length of the third section in the longitudinal direction of the intra-vivo retention device, and the length from the distal end to the proximal end of the second arcuate portion in the longitudinal direction of the intra-vivo retention device is shorter than the length of the third section in the longitudinal direction of the intra-vivo retention device.

8. The intra-vivo indwelling device according to claim 1, wherein the length of the first section in the longitudinal direction of the intra-vivo indwelling device is shorter than the length of the third section in the longitudinal direction of the intra-vivo indwelling device, and the length of the second section in the longitudinal direction of the intra-vivo indwelling device is shorter than the length of the third section in the longitudinal direction of the intra-vivo indwelling device.

9. The in-vivo indwelling device according to claim 1, wherein the radius of curvature of said first arcuate portion is 80% or more and 120% or less of the radius of curvature of said second arcuate portion.

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