JP6155765B2 - Gastrointestinal stent - Google Patents

Description

  The present invention relates to a stent that is inserted into a stenosis part or the like of a lumen part of a tubular organ in a living body to be used for improvement of stenosis, and in particular, appropriately prevents the perforation of the wall of a digestive system body lumen. The present invention relates to a gastrointestinal stent that can be used.

  If a stenosis or occlusion occurs due to, for example, cancer cells, in the lumen of a digestive system such as a bile duct, esophagus, duodenum, or large intestine in a living body, insert a stent into the stenosis or occlusion. Indwelling and improving stenosis, securing a lumen, maintaining the diameter of a lumen, and the like are performed at medical sites (see, for example, Patent Document 1).

  Various types of stents are used as this type of stent, but a cylindrical stent having a meshed surface made of metal is generally used. Moreover, as such a stent, as a main thing resulting from a manufacturing method, the braided type formed by weaving or weaving a wire (filament), and a mesh-like cylinder by laser cutting a cylindrical material The laser cut type that forms Laser-cut stents have little shortening and a high degree of design freedom, and have been widely used in recent years (see, for example, Patent Document 2).

JP 2011-156083 A JP 2007-014675 A

  By the way, the laser cut type stent tends to be sharper at the periphery of the linear portion of the stent as compared with the braided type stent manufactured by netting a linear material. On the other hand, stents are often introduced and placed with a diameter slightly larger than the diameter of the body lumen to be introduced and placed. In addition, gastrointestinal stents are often larger in diameter than stents for blood vessels. For these reasons, when the gastrointestinal stent is manufactured by a laser cut type, the lumen of the digestive system body lumen may be damaged or perforation may occur.

  For example, in the conventional stent 90 as shown in FIG. 7, the end portion 91 may be a sharp end portion (terminal portion), and if this touches the tube wall of the body lumen, the tube wall is damaged. And may cause perforation.

  The present invention has been made to solve such a problem, and its object is to reduce the possibility and frequency of the end of the stent contacting the wall of the digestive system lumen. An object of the present invention is to provide a gastrointestinal stent that can appropriately prevent damage to the tube wall and perforation by the end of the stent.

  In order to solve the above-mentioned problems, the digestive tract stent of the present invention is a cylindrical stent in which annular unit patterns that are radially expandable are connected to each other by connecting portions and are arranged in the axial direction. The stent is placed in a body lumen and has an axial end bent radially inward.

  Preferably, in the digestive tract stent of the present invention, an end wire is formed at the end of the axial end of the digestive tract stent, and the end wire is bent radially inward. Features.

  Preferably, in the gastrointestinal stent of the present invention, a plurality of the end wires formed with respect to the axial end of the gastrointestinal stent are connected to form a new end, and the new end The portion is bent radially inward.

  Also preferably, the gastrointestinal stent of the present invention is characterized in that a spherical body is disposed at the end in the axial direction, the end of the end wire, or the end of the new end.

  According to the present invention, it is possible to reduce the possibility that the end portion of the stent contacts the tube wall of the digestive system body lumen, and digestion that can appropriately prevent damage or perforation of the tube wall due to the end of the stent. A tube stent can be provided.

FIG. 1 is a view schematically showing a structure of a digestive tract stent according to a first embodiment of the present invention, FIG. 1 (A) is a perspective view near one end portion, and FIG. It is a side view near an end. FIG. 2 is a diagram schematically showing the structure of the gastrointestinal stent according to the second embodiment of the present invention. FIG. 2 (A) is a perspective view near one end, and FIG. It is a side view near an end. FIG. 3 is a view schematically showing the structure of a digestive tract stent according to a third embodiment of the present invention, FIG. 3 (A) is a perspective view of one end portion, and FIG. It is a side view near an end. FIG. 4 is a view schematically showing the structure of the gastrointestinal stent of the third embodiment of the present invention shown in FIG. 3, and is a developed view of the vicinity of the end portion. FIG. 5 is a diagram schematically showing the structure of a gastrointestinal stent according to a fourth embodiment of the present invention. FIG. 5 (A) is a perspective view near one end, and FIG. It is a side view near an end. FIG. 6 is a diagram schematically showing the structure of the digestive tract stent according to the fourth embodiment of the present invention shown in FIG. 5, and is a development view in the vicinity of the end portion. FIG. 7 is a view schematically showing the structure of a conventional gastrointestinal stent. FIG. 7A is a perspective view of the vicinity of one end, and FIG. 7B is a side view of the vicinity of the end. It is.

First Embodiment A first embodiment of the present invention will be described with reference to FIG.
FIG. 1 is a schematic view of a digestive tract stent 10 according to the first embodiment of the present invention, in which FIG. 1 (A) is a perspective view and FIG. 1 (B) is a side view. In addition, the digestive tract stent 10 shown in FIG. 1 is a figure which shows the state which the digestive tract stent 10 expanded.

  As shown in FIG. 1, the digestive tract stent 10 has a tubular outer shape, and is placed in a digestive system body lumen such as a bile duct, esophagus, duodenum, large intestine, and is used mainly for the purpose of securing the lumen. Is done. The digestive tract stent 10 of this embodiment is not a so-called covered stent whose outer peripheral surface is covered with a resin film or the like, but is a bare stent that is not covered with a film or the like.

  The gastrointestinal stent 10 has a structure in which a plurality of annular unit patterns 11 expandable in the radial direction are arranged and connected in the axial direction. As shown in the figure, the annular unit pattern 11 is a portion formed of a zigzag linear member pattern formed along the circumferential direction within a predetermined width in the axial direction. In the annular unit pattern 11, the annular unit patterns 11a and 11b whose phases are opposite to each other are arranged alternately in the axial direction so that the phases of the zigzag patterns are sequentially reversed between adjacent annular unit patterns 11. A plurality are sequentially arranged. As a result, as shown in the figure, the bent portions of the zigzag patterns arranged on both sides in the axial direction of each annular unit pattern 11 are arranged adjacent to each other in the adjacent annular unit patterns 11.

  In the annular unit patterns 11 arranged in this way, three of the bent portions arranged adjacent to each other between the adjacent annular unit patterns 11 are connected as the connecting portions 12, and the adjacent annular unit patterns 11 are connected to each other. Is done. A plurality of annular unit patterns 11 are sequentially connected by such connecting portions 12, thereby forming a cylindrical digestive tract stent 10 as a whole.

  In the gastrointestinal stent 10 having such a configuration, the pattern of the linear member is bent inward in the radial direction in the end regions 11c on both sides thereof. In the gastrointestinal stent 10 of the present embodiment, with respect to the annular unit pattern 11 in the terminal region 11c, the outer diameter of the terminal is 60% or more of the outer diameter of the main body of the gastrointestinal stent 10 (the region other than the central terminal region 11c). It is bent inward so as to be in a range of less than 100%, preferably in a range of 60% to 95%. As a result, the possibility that the sharp ends 11d at both ends of the gastrointestinal stent 10 may contact the tube wall of the digestive system body lumen can be reduced, and the tube wall is damaged by the end of the gastrointestinal stent 10. And can prevent perforation.

  The gastrointestinal stent 10 is provided with one or more markers (not shown). The marker is made of, for example, an X-ray contrast material (X-ray opaque material). When the digestive tract stent 10 is placed in a body lumen, the position of the marker is confirmed under X-ray contrast, thereby The indwelling site of the stent 10 can be grasped.

  The wire diameter of the linear portion constituting the mesh pattern of the gastrointestinal stent 10 (annular unit pattern 11) is preferably about 0.05 to 1 mm. Further, when the linear portion is a strip having a rectangular cross section, for example, the length in the long side direction is 0.1 to 1 mm and the length in the short side direction is about 0.05 to 0.5 mm. It is preferable.

  The outer dimensions of the gastrointestinal stent 10 vary depending on the size of the body lumen in which the gastrointestinal stent 10 is placed. For example, the outer diameter is 2 to 30 mm, the inner diameter is 1 to 29 mm, and the length is 5 to 200 mm. It is. Moreover, in the case of the digestive tract stent 10 used as a biliary stent, the outer dimensions are preferably 5 to 20 mm in outer diameter, 4 to 19 mm in inner diameter, and 10 to 100 mm in length. The outer diameter of the gastrointestinal stent 10 is reduced to about a fraction of the above-described value when the gastrointestinal stent 10 is transferred to the indwelling site by a stent delivery device or the like.

  The material of the digestive tract stent 10 of the present embodiment is a metal such as nickel titanium (Ni—Ti) alloy, stainless steel, tantalum, titanium, cobalt chromium alloy, magnesium alloy and the like. Among these, a superelastic alloy such as a Ni—Ti alloy is particularly preferable.

  Examples of the X-ray contrast material used for the marker include gold, platinum, platinum iridium alloy, platinum, silver, and stainless steel. Moreover, the marker may be comprised with the resin molding containing the powder of an X-ray contrast material. As the powder of the X-ray contrast material used for the marker, barium sulfate powder, bismuth subcarbonate powder, tungsten powder, the above-described metal powder, and the like can be used.

  When manufacturing the gastrointestinal stent 10 having such a configuration, first, for example, laser processing (for example, using a YAG laser) is performed on a cylindrical body (pipe) made of a material for forming the gastrointestinal stent 10 ( By laser cutting, a pattern as shown in the figure is formed. Next, a predetermined heat treatment is performed to perform shaping (shape memory). The inward bending and bending of the end are also shaped at this time. Then, grinding | polishing, such as electric field grinding | polishing, is performed, a marker is attached, and the digestive tract stent 10 is manufactured.

  Further, such a digestive tract stent 10 is placed in a stenosis portion or the like in a digestive system body lumen by a so-called stent delivery device. The stent delivery device has a catheter portion having an inner tube and an outer tube through which the inner tube is slidably inserted. The stent is placed on a stent placement portion provided near the distal end of the inner tube. The stent is held in a reduced diameter inside the vicinity of the distal end of the tube, and the distal end of the catheter portion is guided to the intended indwelling site. At this time, the catheter part is advanced along the guide wire inserted into the inner tube and previously inserted into the lumen, and the distal end thereof is introduced to the site where the stent is placed. When the stent placement portion reaches the indwelling site, the stent is exposed from the outer tube by sliding the outer tube toward the proximal end side with respect to the inner tube at the proximal end side of the catheter portion. The diameter is expanded and indwelled.

  As described above, in the gastrointestinal stent 10 of the present embodiment, the stent body is bent radially inward in both end regions 11c. As a result, it is possible to reduce the possibility that both end portions come into contact with the tube wall of the digestive system body lumen, and damage and perforation of the tube wall due to the end of the digestive tract stent 10 can be appropriately prevented.

Second Embodiment A second embodiment of the present invention will be described with reference to FIG.
2A and 2B are schematic views of a digestive tract stent 20 according to the second embodiment of the present invention, in which FIG. 2A is a perspective view and FIG. 2B is a side view. In addition, the digestive tract stent 20 shown in FIG. 2 is a figure which shows the state which the digestive tract stent 20 expanded.

  The basic configuration of the gastrointestinal stent 20 of the second embodiment is the same as the gastrointestinal stent 10 of the first embodiment described above. Therefore, here, the same reference numerals are used for the same configuration as the gastrointestinal stent 10 of the first embodiment, and the description thereof is omitted. Moreover, the material of each part of the digestive tract stent 20, the manufacturing method, the introduction method into the digestive system body lumen, and the like are the same as in the first embodiment. Therefore, these descriptions are also omitted here.

  The difference between the gastrointestinal stent 20 of the second embodiment and the gastrointestinal stent 10 of the first embodiment is the structure of the gastrointestinal stent 20 in the end regions 11c on both sides thereof. In the gastrointestinal stent 20, an end wire 23 different from the annular unit pattern 11 (11a, 11b) is separately formed in the end regions 11c on both sides of the stent, and the end wire 23 is bent radially inward. It is configured in the form.

  The end wire 23 is connected to each of the sharp end portions 11d of the annular unit pattern 11 at the end portion of the digestive tract stent 20, and the first end wire 23a is connected to two ends from the two end portions 11d. The first end wire 23a is further connected to one second end wire 23b. The entire end wire 23 including the first and second end wires 23a and 23b is bent radially inward. The end wire 23 is formed to have a length of 1 to 15 mm, for example, and the outer diameter of the end thereof is preferably in the range of 60% to less than 100% of the outer diameter of the main body, preferably 60% to 95%. It is comprised in the form bent inside so that it may become a range.

  In the present embodiment, the end wire 23 is also made of the same material as that of the main body of the digestive tract stent 20 and manufactured by the same manufacturing method including the laser cutting process. However, the manufacturing method which connects the end part wire 23 to the main body of the digestive tract stent 20 later may be sufficient.

  Thus, also in the gastrointestinal stent 20 of the second embodiment, the distal end of the gastrointestinal stent 20 is bent radially inward in the end regions 11c on both sides thereof. Therefore, it is possible to reduce the possibility that both end portions of the gastrointestinal stent 20 come into contact with the tube wall of the digestive system body lumen, and to appropriately prevent damage or perforation of the tube wall by the end of the gastrointestinal stent 20. it can

Third Embodiment A third embodiment of the present invention will be described with reference to FIGS.
3 and 4 are schematic views of a digestive tract stent 30 according to a third embodiment of the present invention, in which FIG. 3 (A) is a perspective view, and FIG. 3 (B) is a side view. 4 is a development view thereof. In addition, the digestive tract stent 30 shown in FIG. 3 is a figure which shows the state which the digestive tract stent 30 expanded.

  The basic configuration of the gastrointestinal stent 30 according to the third embodiment, the material of each part, the manufacturing method, the method of introducing the gastrointestinal system into the intraluminal lumen of the gastrointestinal tract, etc. Since it is the same as the digestive tract stent 20 of the embodiment, the same reference numerals are used for the same components as those here, and the description thereof is omitted.

  In the digestive tract stent 30 of the third embodiment, end wires 33 different from the annular unit pattern 11 are formed in the end regions 11c on both sides of the stent, and a ball (spherical body) 34 is separately provided at the end portion. The end wire 33 and the ball 34 are entirely bent in the radial direction.

  The end wire 33 is a wire having one end connected to each of the sharp ends 11 d of the annular unit pattern 11 at the end of the digestive tract stent 30. The three end wires 33 from the three end portions 11d are connected at the other end, and the ball 34 is installed at the connection portion.

  The ball 34 is a spherical body made of a material that is compatible with a living body, such as stainless steel, tantalum, gold, platinum, tungsten, ceramic, and resin. In the case where the ball 34 is formed of an X-ray contrast material, the ball 34 can also function as a marker for confirming the position under X-ray contrast. The ball 34 is the other end of the end wire 33 by a mechanical method such as electric discharge machining or deformation, by laser welding, or using an adhesive or the like. The wire 33 is fixed to the connected place. The end wire 33 is made of the same material as the main body of the gastrointestinal stent 30 and is manufactured by the same manufacturing method as the gastrointestinal stent 30 including the laser cutting process.

  In the gastrointestinal stent 30, the whole including the end wire 33 and the ball 34 is bent radially inward at the end of the gastrointestinal stent 30. As in the second embodiment, these are formed to have a length of, for example, 1 to 15 mm, and the outer diameter of the terminal is in the range of 60% or more and less than 100% of the outer diameter of the main body, preferably 60% or more and 95. It is configured in a shape bent inward within a range of% or less.

  Thus, also in the gastrointestinal stent 30 of the third embodiment, the ends of the gastrointestinal stent 30 are bent radially inward in the regions 11c on both ends of the gastrointestinal stent. Therefore, it is possible to reduce the possibility that both end portions of the digestive tract stent 30 come into contact with the tube wall of the digestive system body lumen. In particular, in the digestive tract stent 30 of the third embodiment, since the ball 34 is installed at the end thereof, even if the ball 34 contacts the tube wall of the digestive system body lumen, the tube wall is damaged. The possibility is low, and damage or perforation of the tube wall by the end of the digestive tract stent 30 can be prevented more appropriately.

Fourth Embodiment A fourth embodiment of the present invention will be described with reference to FIGS.
5 and 6 are schematic views of a digestive tract stent 40 according to a fourth embodiment of the present invention, in which FIG. 5 (A) is a perspective view, and FIG. 5 (B) is a side view. 6 is a development view thereof. In addition, the digestive tract stent 40 shown in FIG. 5 is a figure which shows the state which the digestive tract stent 40 expanded.

  The basic configuration of the gastrointestinal stent 40 of the fourth embodiment, the material of each part, the manufacturing method, the method of introducing the gastrointestinal system into the intraluminal lumen of the gastrointestinal tract, etc. Since it is the same as the digestive tract stent 20 of the embodiment, the same reference numerals are used for the same components as those here, and the description thereof is omitted.

  In the gastrointestinal stent 40 of the fourth embodiment, the lengths of the second end wires 23b of the end wires 23 of the gastrointestinal stent 20 of the second embodiment are not uniform, and the second end wires It can be said that a ball (spherical body) 34 is installed at the end of 23b. That is, in the digestive tract stent 40, an end wire 43 different from the annular unit pattern 11 (11a, 11b) is separately formed in the end regions 11c on both sides of the stent, and further on the end of the end wire 43. A ball 34 is provided, and the entire end portion including the end wire 43 and the ball 34 is bent radially inward.

  The end wire 43 is formed with a first end wire 43a for each of the sharp ends 11d of the annular unit pattern 11 at the end of the digestive tract stent 20, and two ends from the two ends 11d. The first end wire 43a is further connected to one second end wire 43b. The length of the second end wire 43b is not uniform and is designed to be positively different. And the ball | bowl 34 similar to the digestive tract stent 30 of 3rd embodiment is fixed to the terminal of this end part wire 43b.

  In the gastrointestinal stent 40, the entire end of the gastrointestinal stent 40 including the first and second end wires 43a and 43b and the ball 34 is bent radially inward. The entire ends of these digestive tract stents 40 including the wires 43a and 43b and the balls 34 are formed to have a length of, for example, 1 to 15 mm, and the outer diameter of the terminal is 60% or more and less than 100% of the outer diameter of the main body. It is configured to be bent inward within a certain range.

  The end wire 43 is also made of the same material as that of the main body of the digestive tract stent 40 and manufactured by the same manufacturing method including a laser cutting process. However, the manufacturing method which connects the end part wire 43 to the main body of the digestive tract stent 40 later may be sufficient.

  Thus, also in the digestive tract stent 40 of the fourth embodiment, the distal end of the digestive tract stent 40 is bent radially inward in the end regions 11c on both sides thereof. Therefore, it is possible to reduce the possibility that both end portions of the digestive tract stent 40 come into contact with the tube wall of the digestive system body lumen. In particular, in the digestive tract stent 40 of the fourth embodiment, since the ball 34 is installed at the end thereof, even if the ball 34 contacts the tube wall of the digestive system body lumen, the tube wall is damaged. The possibility is low, and damage or perforation of the tube wall by the end of the digestive tract stent 40 can be prevented more appropriately.

  Furthermore, in the digestive tract stent 40 of the fourth embodiment, the length of the wire 43b of each end wire 43 is different from the length of the wire 43b of the end wire 43 adjacent in the circumferential direction. . Therefore, the position of the ball 34 fixed to the end of the end wire 43 is also different from the position of the ball 34 of the end wire 43 adjacent in the circumferential direction in the axial direction. As described above in the description of the gastrointestinal stent 10 according to the first embodiment, the gastrointestinal stent 40 is placed in the stent delivery device while being held in a state of being reduced in diameter between the inner tube and the outer tube. Guided to the site. At this time, in the digestive tract stent 40 in which the positions of the balls 34 adjacent to each other in the circumferential direction are different in the axial direction, the presence of the balls 34 is not easily disturbed in the outer tube of the stent delivery device, and the digestive tract stent 40 including the balls 34 is provided. Even so, it can be appropriately introduced into the indwelling site using a conventional stent delivery device. Therefore, the gastrointestinal stent 40 with extremely good operability can be provided.

Modifications The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the present invention.

  For example, in each embodiment mentioned above, the annular unit pattern which comprises a digestive tract stent was made into the zigzag pattern along the circumferential direction. However, the shape of the pattern constituting the gastrointestinal stent is not limited to this, and may be any shape as long as the pattern can be expanded, deformed, and exhibit appropriate flexibility.

  Moreover, in each embodiment mentioned above, the cyclic | annular unit pattern which comprises a gastrointestinal tract stent shall be connected sequentially by the three connection parts. However, the number and configuration of the connecting portions are not limited to this, and any number and configuration may be used as long as the gastrointestinal stent as a whole can exhibit moderate flexibility and followability particularly in the axial direction. .

  Moreover, in each embodiment mentioned above, the terminal part shall be bent inward by the same structure about the terminal area | region 11c of the both sides of a digestive tract stent. However, the both ends of the gastrointestinal stent may be configured to be bent inwardly by different configurations. For example, one end of the digestive tract stent has a form in which an end wire 23 is formed in the terminal region 11c as in the second embodiment described above, and the other end as in the third embodiment described above. Different forms may be provided on both sides, such as a form in which the ball 34 is formed in the end region 11c.

  In the second embodiment described above, the end wire 23 forms one second end wire 23b with respect to the two sharp end portions 11d of the distal region 11c on both sides of the digestive tract stent 20. Was. However, the configuration of the second end wire 23b is not limited to this. For example, a configuration in which one second end wire 23b is installed at three or more sharp end portions 11d is also possible. Good. A similar modification is possible for the end wire 43 of the fourth embodiment.

10, 20, 30, 40, 90 ... Gastrointestinal stent 11 ... Annular unit pattern 12 ... Connection part 23, 33, 43 ... End wire 34 ... Ball 91 ... Sharp end

Claims (4)

A cylindrical stent in which radially expandable annular unit patterns are connected to each other by connecting portions and arranged in the axial direction,
This stent is placed in the digestive system lumen, and the axial end is radially inward so that the outer diameter of both ends in the axial direction is in the range of 60% to less than 100% of the outer diameter of the central part. A gastrointestinal stent characterized by bending.   The gastrointestinal tract according to claim 1, wherein an end wire is formed with respect to the end of the axial end of the gastrointestinal stent, and the end wire is bent radially inward. Stent.   A plurality of end wires formed to the end of the axial end of the gastrointestinal stent are connected to form a new end, and the new end is bent radially inward. The gastrointestinal stent according to claim 2.   4. A gastrointestinal stent according to any one of claims 1 to 3, wherein a spherical body is disposed at the end in the axial direction, the end of the end wire, or the end of the new end. .

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