JP2019103667A - Living body absorbent stent and medical equipment including the same - Google Patents

Abstract

A bioabsorbable stent and a medical device that are bioabsorbable, highly self-expandable, and capable of maintaining a shape in a bent state after being self-expanded. A stent (1) according to the present invention is a stent in which a plurality of bioabsorbable filament yarns (2, 3) are formed into a cylindrical braid, and the braid includes a plurality of non-strands in the length direction. The elastic yarn (7a-7c) is incorporated as a warp, and when the stent (1) is expanded and left unloaded, the warp is in a loose state, the stent is self-expanding, and the stent The shape can be maintained in a self-expanded and bent state. When the stent is expanded and allowed to stand in an unloaded state, the warp length is preferably 120 to 200% with respect to the stent length of 100%. In the medical device of the present invention, the above-described bioabsorbable stent is mounted in a delivery system after being compressed. [Selection] Figure 1

Description

  The present invention relates to a bioabsorbable stent for insertion into a duct of a living body such as a digestive tract, a bile duct, a pancreatic duct, a blood vessel, a ureter, and a trachea, and a medical device including the same. In particular, the present invention relates to a bioabsorbable stent capable of maintaining its shape in a bent state after self-expansion and a medical device including the same.

A lumen in the body is constricted due to various causes, and stenting is often performed as a treatment. Typically, the stent is loaded in a compressed state into a delivery system and carried to the site of the stenosis where it is expanded and deployed. In the case of a stent that does not expand or does not have a self-expanding force, balloon expansion needs to be performed from the inside of the stent. It is difficult to apply this balloon dilation to the operation of a surgeon in order not to damage the lumen, and to a long stenosis or a stenosis at a bending site. On the other hand, a self-expanding stent can be simply deployed simply by releasing the compressed state at the stenosis site.
Conventionally, a metal stent using a shape memory alloy such as a nickel-titanium alloy (nitinol) has mainly been used as a material of a self-expanding stent, and it has already been used for digestive tracts such as esophagus, duodenum and large intestine, and for bile ducts A stent is being used. Among them, in the case of a blood vessel or a lumen having an extremely bent portion such as the intestine, if the force to return straight (axial force) is strong when expanding the stent, there is a risk of perforation, so the expansion force In addition, it has a structure that can be maintained in a bent shape. In Patent Document 1, smooth bending characteristics are made possible by alternately knitting a shape memory alloy wire constituting a stent at an obtuse angle and an acute angle.

However, in benign gastrointestinal strictures such as intestinal strictures that frequently occur in patients with Crohn's disease and ulcerative colitis, and stenosis after endoscopic submucosal dissection of esophageal cancer, metal stents that are foreign substances for a long time Placing the indwelling in the body is at high risk such as perforation due to movement of the stent. In addition, in the case of in-stent restenosis caused by restenosis after treatment with a metal stent, the treatment method for the vascular stent is limited. Due to these facts, the demand for practical bioabsorbable stents has been increasing recently. At present, as bioabsorbable materials used for stents, polymers such as polylactic acid, polyglycolic acid, polydioxanone, polycaprolactone or copolymers thereof are widely used. However, these bioabsorbable polymers usually have a lower expansion force compared to nickel-titanium alloy (nitinol) metal stents. Therefore, it has been an issue to simultaneously improve the expansion force and maintain the bending characteristics depending on the type of polymer used, the diameter of fibers, the number of fibers used, and the method of assembling the cylinder.
Patent Document 2 proposes a bioabsorbable self-expanding stent, and the self-expanding property is imparted by the crossing angle of two sets of filaments used and the tensile strength of the filaments.
According to Patent Document 2, by arranging reinforcing bars extending along the axial direction in a plurality in the circumferential direction of the cylinder, the elongation in the cylinder axial direction is suppressed, and the restorability and deformation resistance after deformation are suppressed. Although an improved bio-channel stent is shown, it can not be expected to be self-expanding, nor can it be compressed and loaded into a delivery system. Although the stent which used the braid etc. is disclosed also in patent documents 4-6, it was difficult to carry out compression loading to a delivery system. According to Patent Document 7, the delivery carrier can be opened and the stent is expanded by being pulled by elastic cords at both ends of the stent, but since the stent becomes straight, it does not have smooth bendability.

Japanese Patent Application Publication No. 2014-512195 Japanese Patent Application Laid-Open No. 11-57018 JP, 2009-160079, A Japanese Patent Laid-Open No. 2002-002076 Japanese Patent Publication No. 2004-528115 JP-A-2015-155005 WO 2016/035757

  The conventional self-expanding bioabsorbable stent has a problem in achieving both the expansion force and the smooth bendability.

  The present invention is intended to solve such problems, and improves the convenience etc. in the medical field, and is highly self-expanding according to the purpose of use of the stent, such as a lumen or a disease to be applied, and Provided are a bioabsorbable stent capable of maintaining its shape in a bent state after self-expansion and a medical device including the same.

  The stent of the present invention is a stent in which a plurality of bioabsorbable filament yarns are formed into a cylindrical braid, and in the braid, a plurality of inelastic yarns are incorporated as a warp in the lengthwise direction, When the stent is expanded and left in the unloaded state, the warp is in a relaxed state, the stent is self-expanding, and the stent is capable of maintaining its shape in a self-expanding and bending state. It is characterized by

  The medical device of the present invention is characterized in that the bioabsorbable stent is loaded in a delivery system.

  The bioabsorbable stent of the present invention is a stent in which a plurality of bioabsorbable filament yarns are formed into a cylindrical braid, and in the braid, a plurality of inelastic yarns are incorporated as a warp in the longitudinal direction. When the stent is expanded and left in a non-loaded state, the warp is in a relaxed state, and the stent is self-expanding to be bioabsorbable, highly self-expanding, and self-expanding. When bent in the expanded state, the shape can be maintained in the bent state. That is, by inserting a plurality of inelastic yarns as warps, when the stent is bent in a self-expanded state, the shape can be maintained in the bent state. If the shape can be maintained in a bent state, it can be inserted following the shape of a tube in the living body, thereby preventing an accident such as damaging the living body. The present invention has a great advantage in that such return force (axial force) is reduced.

FIG. 1A is a schematic side view of a stent according to an embodiment of the present invention, and FIG. 1B is a schematic cross-sectional view showing the arrangement of the same warp. FIG. 2 is a schematic explanatory view showing that the shape is maintained in a bent state when the stent is bent after self-expansion. FIG. 3 is a schematic explanatory view showing the braid manufacturing apparatus. FIG. 4A is a schematic partial explanatory view for inserting a warp of the braid manufacturing apparatus, and FIG. 4B is an operation diagram showing the movement of the bobbin. FIG. 5 is an actual photograph of the braided stent after expansion. FIG. 6 is an actual photograph of the braided stent maintained in a bent shape after expansion. FIG. 7 is an actual photograph of the central portion of the braided stent in a tension state. FIG. 8 is an actual photograph showing the self-expanding state when the braided stent is pushed out of the cylinder. FIG. 9 is a schematic side view of the delivery device on which the stent is mounted.

  The stent of the present invention is obtained by forming a plurality of bioabsorbable filament yarns into a cylindrical braid. In this braid, a plurality of inelastic yarns are incorporated as warps in the length direction, and when the stent is expanded and left in a non-loaded state, the warps are in a loose state and do not inhibit the self-expansion of the stent. When a plurality of inelastic yarns are inserted as a warp, when the stent is bent in a self-expanded state, the inelastic yarns become resistance, and the shape can be maintained in the bent state. The number of the non-elastic yarns is preferably 2 to 6, and more preferably 3 to 6. If the number is in this range, the stent maintains its bent shape regardless of the bending direction. It is preferable that the inelastic yarns be disposed at substantially equal angles when viewed in the cross-sectional direction of the stent. In the braid, a plurality of elastic yarns may be incorporated as warps in the longitudinal direction. Incorporating elastic threads further enhances the self-expandability of the stent. It is preferable to arrange 2 to 6, preferably 3 to 5 elastic yarns at positions where they have a substantially uniform angle when viewed in the cross-sectional direction of the stent.

  When the stent is expanded and left in a non-loaded state, the length of the warp is preferably 120 to 200% with respect to 100% of the length of the stent, more preferably 100% of the length of the stent The length of the warp is 130 to 180%. When the warp is longer than the length of the stent as described above, the warp is loosened and the elastic thread is secured free movement and stretchability, resulting in a stent with high self-expansion and deformation recovery. . Further, the inelastic yarn exhibits the reduction of the axial force.

  The expansion ratio in the diametrical direction from the pulled state of the stent to the released state (unloaded state) is preferably more than 5 times, more preferably 6 times or more. The upper limit is better as the magnification is higher. Within the above range, delivery to the affected area can be performed using a narrow inner diameter delivery, and the constriction site can be expanded, so that the burden on the patient can be reduced.

  Each filament yarn constituting the braid may be a monofilament yarn or a multifilament yarn, but is preferably a monofilament yarn. Monofilament yarn has high rigidity and is convenient for expanding a living body tube.

The filament yarn preferably comprises 16 (16 strikes) or more, more preferably 24 (24 strikes) or more, and more preferably 32 (32 strikes) or more. The upper limit is preferably 64 (64 shots) or less. Within the above range, the density of the braid is high, so that the expansion force is high, and the contact point of the inelastic yarn is increased, which makes it easier to maintain the bent shape.
For the same reason, the assembly angle of each filament yarn (filament yarn) constituting the braid is preferably 30 to 80 °. The preferred angle is 35-75. If the braided yarn has the above-mentioned range, it is easy to maintain a high expansion force and a bent shape, and there is no distortion in the braided shape, and a braided cord having a cylindrical shape can be obtained.
Here, the pairing angle means an acute angle between the length direction of the whole braid and the knitting direction. Also, the number of sets is 3 / inch or more, preferably 4 to 18 / inch. Thus, the yarn density and the assembly density are high, the strength is also high, and the elasticity is also high. There are round and square battings in braids, but the braided and assembled braids are hollow and suitable for stents.

  The diameter of the filament yarn is preferably 0.15 to 1.0 mm, more preferably 0.15 to 0.8 mm, and more preferably 0.15 to 0.4 mm. If it is the said range, it has high expansion force and does not suppress delivery carrying property.

  The hollow diameter of the stent applied to the intestinal tract is preferably 2 to 50 mm, more preferably 5 to 30 mm, and still more preferably 10 to 25 mm when the stent is expanded and left in a non-loaded state. If it is the said range, the intestinal tract of a biological body can fully be expanded. In addition, the diameter at the time of delivery mounting may be 2.3 mm or less, and the diameter of the stent at the time of expansion may be 20 mm or more. In this way, it is easy to insert and indwell in a living body using a delivery system or the like distributed in the market.

  The polymers constituting the biodegradable filament yarn are polyglycolic acid, poly-L-lactic acid, poly-D-lactic acid, polycaprolactone, polydioxanone, polyethylene glycol, biodegradable synthetic polymers which are copolymers thereof, collagen, It is preferably at least one selected from biodegradable natural polymers such as gelatin, glycosaminoglycan, chitin, chitosan, hyaluronic acid, alginic acid and silk fibroin, spider silk fibroin and the like. The degradation time in vivo is said to be approximately 2 weeks for polyglycol, approximately 6 months for polylactic acid yarn, and 1 to 2 years for polycaprolactone for biodegradable synthetic polymers, but the copolymer ratio and , Polymer blend, molecular weight, degree of crystallinity can be adjusted. With regard to biodegradable natural polymers, the degradation period in the living body can be adjusted by molecular weight, structure control, addition of a crosslinked structure, and the like. In the stent of the present invention, the main part of the braid is formed of biodegradable filament yarn, so the polymer is biodegradable in a predetermined period and excreted even if it contains substances that are not biodegradable. I will.

  The ends of the stent are preferably unfrozen. Fraying prevention can be formed by bending of the end of the stent and / or heat fusion of the end yarn, ultrasonic fusion, metal connection such as tube-shaped x opaque marker or the like. Fixing the both ends of the warp to the braid can also be formed by metal connection such as heat fusion, ultrasonic fusion, radiopaque marker or the like.

  It is preferable that any of the yarns constituting the stent contains a substance having an X-ray detection ability. For example, barium sulfate particles are kneaded into a filament yarn constituting a braid. In this way, the position of the stent can be accurately detected by X-ray irradiation from outside the living body, and the presence or absence of bioabsorption can also be detected. Alternatively, detection may be carried out by passing a filament yarn constituting a braid through an X-ray contrasting metal tube or coil of platinum, platinum / palladium, platinum / iridium, platinum / tungsten or the like.

  The stent has a maximum load at 75% displacement (15 mm displacement for a diameter of 20 mm) from a diameter in the expanded state in a compression deformation test in which pressure is applied diametrically from an expanded state, and a commercially available metal stent It is preferable that it is equal to or more than that. Within this value range, sufficient expansion power is obtained.

  The length of the stent is preferably 50 to 200 mm, more preferably 80 to 120 mm, when applied to the intestinal tract. If it is this range, it is convenient to detain at a target stenosis using a delivery system.

  The non-elastic yarn of the warp can use the same polymer as that constituting the biodegradable filament yarn. For example, biodegradable synthetic polymers which are polyglycolic acid, polylactic acid, polycaprolactone, polydioxanone and copolymers thereof, collagen, gelatin, glycosaminoglycan, chitin, chitosan, hyaluronic acid and silk fibroin, spider silk fibroin It is preferable that it is at least one selected from biodegradable natural polymers such as. The inelastic yarn is preferably a filament yarn having a diameter of 0.1 to 0.5 mm, more preferably a filament yarn having a diameter of 0.15 to 0.4 mm. Within this range, delivery loadability is not suppressed. Inelastic yarn is incorporated by warp insertion at the time of braid manufacture.

  When an elastic yarn is used as a warp, a biocompatible rubber, a polyurethane yarn or a thermoplastic elastomer yarn can be preferably used. As a biocompatible polyurethane thread, there is, for example, a trade name "Pellethane" manufactured by Lubrizol Corporation of the United States, which is a US class VI-compliant product. The polyurethane yarn is preferably a filament yarn having a diameter of 50 to 500 μm, more preferably a filament yarn having a diameter of 50 to 300 μm. The elastic yarn may be incorporated by warp insertion at the time of braid manufacture, or may be attached to the outside of the braid after manufacture.

  The braiding machine can mainly change the thickness (inner diameter, outer diameter) of the braid depending on the number of strikes. When assembling a string in the stringing process, in the center of the stringing machine, vertically move up or down a round or polygonal metal or wooden rod with a rounded end whose tip portion approximately corresponds to the inner diameter of the string from the bottom However, by assembling (pushing up), a cylindrical braid can be obtained. In addition, it is possible to stabilize the shape by installing a heater at the stage from pushing up to picking up and performing non-contact heat treatment.

  This will be described below using the drawings. In the following drawings, the same symbols indicate the same things. FIG. 1A is a schematic side view of a stent according to an embodiment of the present invention, and FIG. 1B is a schematic cross-sectional view showing the arrangement of the same warp. The stent 1 is assembled by braided yarns 2 and 3. Both end portions 4a and 4b are bent and prevented from fraying. In the stent 1, warps 5a to 5c consisting of three elastic threads in the length direction and warps 7a to 7c consisting of three nonelastic threads are incorporated by warp insertion at substantially equal angles. There is. When the stent 1 is expanded and left in a non-loaded state, the elastic threads 5a-5c of the warp and the inelastic threads 7a-7c of the warp are in a loose state. The braids of the braided yarns of the stent 1 are rough and have gaps. The yarns 2 and 3 are arranged at a predetermined angle in the range of 30 to 75 degrees. The set angle is an angle Θ between the length direction 6 of the whole braid and the direction of the braid 3 as shown in FIG. 1A.

  FIG. 2 is a schematic explanatory view showing that the shape is maintained in a bent state when the same stent is bent after self-expansion. That is, the stent of the present invention is shape maintainable or shape memoryable. With the shape maintainability or the shape memory property, it is possible to follow the shape of the tubular portion in the living body, and prevent an accident that damages the living body. The warps 7a to 7c made of inelastic yarns become loops 8a and 8b because they are longer than the stent 1. The loops 8a and 8b preferably protrude outside the stent 1. As another method of treating a long portion of the inelastic yarns 7a to 7c with respect to the stent 1, the inelastic yarns may be crimped yarns and finely entangled with the braided yarn.

  FIG. 3 is a schematic explanatory view showing an apparatus for manufacturing a round braid used in one embodiment of the present invention. The manufacturing apparatus 10 is configured to include a rack 11, a bobbin (carrier) 12, a mandrel 14, and a driving device (not shown). As the bobbin 12 is rotationally moved on the solid line of the track 19 on the rack 11, the yarn 13 wound around the bobbin 12 is braided on the mandrel 14 to be pushed up, and the braid 17 is created. The push-up portion 16 is composed of a hemispherical head moving up and down in conjunction with the rotational movement of the bobbin 12 and a cylindrical (or polygonal) cylindrical portion 15 at the center thereof. The outer diameter of the cylindrical portion 15 is approximately equal to the inner diameter of the braid 17. The braid 17 is sent to a heater and heat-set if necessary. The braid 17 passes through the takeout guide (pulley) 18 and is shaken off to the storage container. In the above, the mandrel 14 stroke length and the number of strokes are set appropriately. Heat setting can also be added to the braid. Among the warp yarns 20, the elastic yarn is supplied from the yarn winding body 22a, and the non-elastic yarn is supplied to the braid from the yarn winding body 22b. The relation between the warp yarn 20 and the yarn winding body 22 and the pipe 21 will be described with reference to FIGS. 4A-B.

  FIG. 4A is a schematic partial explanatory view for inserting a warp of the same manufacturing apparatus, and FIG. 4B is an operation diagram showing the movement of the bobbin. In FIG. 4A, the warp yarn 20 is supplied from a yarn winding body 22 disposed below the rack 11 and is inserted into the braid from a pipe 21 inside a track (rail) 19 through which the bobbin of the braid passes. The pipe 21 is disposed at a position higher than the bobbin (carrier) 12 of the braided yarn, and passes through the pipe 21 and is inserted into the braid. The relationship between the track (rail) 19 and the pipe is as shown in FIG. 4B, and the pipes 21a to 21f are arranged substantially equally at the center of each track (rail) 19. Among them, elastic threads are passed through the pipes 21a to 21c, and non-elastic threads are allowed to pass through the pipes 21d to 21f.

  FIG. 5 is an actual photograph after expansion of the braided stent obtained as described above. It can be seen that the warp is inserted into the braid in a loose state. The ends are bonded by ultrasonic bonding. FIG. 6 is an actual photograph maintained in a bent shape after expansion of the braid stent.

  FIG. 7 is an actual photograph of the central portion of the braided stent in a tension state. It inserts in a catheter in such a state, and carries it to in-vivo. FIG. 8 is an actual photograph showing a partially self-expanded state when the braided stent is taken out of the tubular delivery on the left side. In the living body, all dilation is performed to dilate the body tube.

  FIG. 9 is a schematic side view of a delivery device 30 mounting a stent 1 according to an embodiment of the present invention. This device includes a hub 31, a pusher 32, a Y connector 33, and an outer sheath 34 having an inner catheter inside, in which the delivery 35 and the stent 1 are mounted. It inserts in the living body in this state. As an example, L1 is 180 mm and L2 is 200 mm.

  Hereinafter, the present invention will be more specifically described using examples and comparative examples, but the present invention is not limited to the following examples.

Example 1
As a biodegradable polymer, polyglycolic acid was melt spun at a temperature of 190 to 245 ° C., stretched at a draw ratio of 4 to 7 times, and heat set at a temperature of 100 to 120 ° C. The diameter of the obtained yarn was 230 μm. The obtained monofilament was used to manufacture a braided stent shown in FIG. 1 using a braided manufacturing apparatus shown in FIGS. 3 to 3 (here, a 32 braided braid manufacturing apparatus). The braided stent has an outer diameter of 20 mm in the expanded state. Polyurethane elastic yarn: 3 yarns of "Pellethane" (filament yarn with a diameter of 300 μm) made by Lubrizol, USA, and 3 filament yarns with a diameter of 230 μm of polyglycolic acid (PGA) as inelastic yarn as warp yarns Then the warp was inserted. The length of the polyurethane elastic yarn was 180% with respect to 100% of the braid length. The length of the inelastic yarn made of PGA was 300% with respect to 100% of the braid length. Further, the combination angle Θ of each monofilament yarn (filament yarn) constituting the braid shown in Fig. 1 was 68 °. The braided stent could be loaded into a delivery with an inner diameter of 2.3 mm and self-expanded to 20 mm outer diameter when extruded from the delivery, expanding 8.7 times. In addition, when bent in the expanded state, as shown in FIG. 2, shape retention was observed.

(Example 2)
A braided stent was produced in the same manner as in Example 1 except that the combination angle Θ of each monofilament yarn (filament yarn) constituting the braid shown in Fig. 1 was 57 °. When the obtained braided stent was bent in the expanded state, its shape retention was recognized as shown in FIG.

(Example 3)
A braided stent was produced in the same manner as in Example 1 except that the set angle Θ of each monofilament yarn (filament yarn) constituting the braid shown in Fig. 1 was 47 °. The obtained braided stent was found to be self-expanding and retain its formability as shown in FIG.

(Comparative example 1)
A braided stent was prepared in the same manner as in Example 1 except that the warp insertion yarn was not used and the braid angle Θ of each monofilament yarn (brad) constituting the braid shown in FIG. 1 was 54 °. The resulting braided stent was neither self-expanding nor form-retaining.

(Comparative example 2)
A commercially available stent (Boston scientific WallFlex stent for large intestine) made of a 260 μm diameter nitinol wire was used. In Comparative Example 2, when it was bent in the expanded state, it returned to its original shape, and no form retention was observed.

  The braided stent according to the present invention is suitable for insertion into the canal of a living body such as a human body, a pet, or a domestic animal.

DESCRIPTION OF SYMBOLS 1 Stent 2, 3 Braided yarn 4a, 4b End 5a-5c Elastic yarn 6 warp whole string length direction 7a-7c Inelastic yarn 8a, 8b Inelastic yarn warp 経 Build-up angle Reference Signs List 10 braid manufacturing apparatus 11 base 12 bobbin 13 thread 14 mandrel 15 cylindrical portion 16 push-up portion 17 braid 18 takeout guide (pulley)
Reference Signs List 19 track 20 warp yarn 21, 21a to 21f pipe 22, 22a, 22b warp yarn winding body 30 delivery device 31 hub 32 pusher 33 Y connector 34 outer sheath 35 delivery 36 compression plate

Claims (14)

A bioabsorbable stent in which a plurality of bioabsorbable filament yarns are formed into a cylindrical braid,
In the braid, a plurality of inelastic yarns are incorporated as warps in the lengthwise direction,
When the stent is expanded and left in an unloaded state, the warp is in a relaxed state,
A bioabsorbable stent characterized in that the stent is self-expanding, and the stent can maintain its shape in a self-expanding and bending state.   The bioabsorbable stent according to claim 1, wherein the length of the warp is 120 to 200% with respect to 100% of the length of the stent when the stent is expanded and left in a non-loaded state.   The bioabsorbable stent according to claim 1 or 2, wherein the expansion ratio in the diametrical direction of the stent is more than 5 times.   The bioabsorbable stent according to any one of claims 1 to 3, wherein each filament yarn constituting the braid is a monofilament yarn.   The bioabsorbable stent according to any one of claims 1 to 4, wherein the filament yarn comprises 16 or more filaments.   The bioabsorbable stent according to any one of claims 1 to 5, wherein the diameter of the filament yarn is 0.15 to 1.0 mm.   The bioabsorbable stent according to any one of claims 1 to 6, wherein the hollow diameter of the stent is 2 to 50 mm when the stent is expanded and left in a non-loaded state.   The polymers constituting the bioabsorbable filament yarns include polyglycolic acid, poly-L-lactic acid, poly-D-lactic acid, polycaprolactone, polydioxanone, polyethylene glycol and copolymers thereof, collagen, gelatin, glycosaminoglycan, chitin The bioabsorbable stent according to any one of claims 1 to 7, which is at least one selected from chitosan, hyaluronic acid, alginic acid and silk fibroin, and spider silk fibroin.   The polymers constituting the plurality of inelastic yarns of the above-mentioned warp yarns are polyglycolic acid, poly-L-lactic acid, poly-D-lactic acid, polycaprolactone, polydioxanone, polyethylene glycol or copolymers thereof, collagen, gelatin, glycosaminoglycan, The bioabsorbable stent according to any one of claims 1 to 8, which is at least one selected from chitin, chitosan, hyaluronic acid, alginic acid and silk fibroin, and spider silk fibroin.   The bioabsorbable stent according to any one of claims 1 to 9, wherein the end of the stent is prevented from fraying.   The bioabsorbable stent according to claim 10, wherein the fray prevention is formed by bending of the end of the stent and / or heat fusion of the end yarn and / or connection by a metal tube.   The bioabsorbable stent according to any one of claims 1 to 11, wherein any of the threads constituting the stent contains a substance having an X-ray detection ability.   The stent according to any one of claims 1 to 12, wherein the stent has a load of 1 N or more when compressed 75% from a diameter of the expanded state in a compression deformation test in which pressure is applied in a diametrical direction from the expanded state. Bioabsorbable stent as described.   A medical device characterized in that the bioabsorbable stent according to any one of claims 1 to 13 is compressed and loaded on a delivery system.