JP2009131397A - Living body organ dilator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a living body organ dilator which is provided with a stent having totally high and uniform dilation maintaining power and sufficiently reducing a diameter when mounted on a living body organ dilator body with less decline of flexibility, and excellently improving a restenosis section. <P>SOLUTION: The living body organ dilator 100 comprises the stent 1 provided with a connection part 3 for connecting an annular body 2 and an adjacent annular body 2 and the living body organ dilator body 101 on which the stent 1 is mounted. The annular body 2 comprises a plurality of bend parts 5 on one end side having vertexes on one end side in the axial direction of the stent, a plurality of bend parts 6 on the other end side having vertexes on the other end side, and a linear component 4 connecting the bend parts on one end side and the bend parts on the other end side, and a multilayered part 43 where the side parts of the adjacent linear components 4 in the respective annular bodies 2 are piled up when mounted on the living body organ dilator body is provided. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a living organ dilator used to improve a stenosis or occlusion occurring in a body lumen such as a blood vessel, a bile duct, a trachea, an esophagus, or a urethra.

A living organ dilator is generally equipped with a stent for improving a stenosis. In order to treat various diseases caused by stenosis or occlusion of blood vessels or other in-vivo lumens, stents are generally placed in order to expand the stenosis or occlusion site and secure the lumen. Specifically, it is a tubular medical device.
Since the stent is inserted into the body from outside the body, the diameter is small at that time. The stent is expanded at the target stenosis or occlusion site to increase the diameter, and the lumen is held as it is.

  As the stent, a metal wire or a cylindrical shape obtained by processing a metal tube is generally used. It is attached to a catheter or the like in a thin state, inserted into a living body, expanded by a certain method at a target site, and tightly fixed to the inner wall of the lumen to maintain the lumen shape. Stents are classified into self-expandable stents and balloon expandable stents according to function and placement method. The balloon expandable stent has no expansion function in the stent itself. After inserting the stent into the target site, the balloon is positioned in the stent to expand the balloon, and the stent is expanded (plastic deformation) by the expansion force of the balloon. Fix it in close contact with the inner surface of the lumen. This type of stent requires the above-described stent expansion operation.

As a stent, it is important to have good vasodilation retention force after expansion. For this reason, as a stent, it is desirable that there is much quantity of the linear component which comprises a stent. However, if the amount of linear components is large, the stent contacts when the diameter of the stent is reduced, so that the diameter reduction rate of the stent is low, and the stent cannot be reduced in diameter.
Japanese Patent Application Publication No. 2005-51502 (Patent Document 1) discloses a multilayer stent in which linear components are partially overlapped.

JP 2005-51502 Gazette

In the stent of Patent Document 1, it may be possible to obtain a good expansion force. However, because of the multilayer structure, it is not sufficient in terms of reducing the diameter, and the overlapping portions are annularly adjacent in the axial direction. Because of the facing parts of the body, the rigidity between the annular bodies is increased, and the flexibility is not good.
An object of the present invention is to provide an overall high and uniform expansion maintaining force, and can be sufficiently reduced in diameter when mounted on a body organ expansion instrument body. It is an object of the present invention to provide a living organ dilator that has a stent with little decrease in flexibility at the time and can improve a good restenosis site.

What achieves the above object is as follows.
(1) A living organ expansion device comprising a stent having a connecting portion that connects a plurality of annular members arranged in the axial direction and the adjacent annular members, and a tube-shaped living organ expansion device body to which the stent is attached. There,
The annular body of the stent includes a plurality of one end side bent portions having apexes on one end side in the axial direction of the stent, a plurality of other end side bent portions having apexes on the other end side in the axial direction of the stent, It is constituted by a linear component that connects the one end side bent portion and the other end side bent portion,
The stent includes a multi-layered portion in which side portions of adjacent linear components in each annular body overlap each other when mounted on the main body of the living organ expanding device, and the living organ expanding device does not overlap in the connecting portion. .

(2) The side surface of the linear component that is the upper layer side in the multi-layer portion is an inclined surface that protrudes from the outer surface side, and the side portion of the linear component that is the lower layer side in the multi-layer portion. The living organ dilator as set forth in (1), wherein the side surface is an inclined surface from which the inner surface side protrudes.
(3) The annular body includes a plurality of linear components having a first trapezoidal cross section in which a cross-sectional shape in a direction orthogonal to a central axis of the stent is long on an outer surface side and slightly curved on an inner surface side, and an inner surface (1) or (2) above, wherein a plurality of linear components having a second trapezoidal cross section that is long on the side and slightly curved on the inner surface side, and are arranged alternately. The biological organ dilator described.
(4) The annular body includes a plurality of linear components having a parallelogram-shaped cross section in which a cross-sectional shape in a direction orthogonal to the central axis of the stent is slightly curved toward the inner surface side. (2) The living organ dilator according to (2).
(5) The living organ expansion device according to any one of (1) to (4), wherein the multilayer portion disappears when the stent is expanded.

(6) The living organ dilator according to any one of the above (1) to (5), wherein the side portions of the linear components adjacent to each other in the annular body are layered portions that overlap substantially over the entire length.
(7) The annular body includes a bulging portion that extends in a circumferential direction of the annular body at a side portion of the linear component, and the multilayer portion is formed by overlapping the bulging portions. The living organ dilator according to any one of 1) to (6).
(8) The living organ dilator according to any one of (1) to (7), wherein the one end side bent portion and / or the other end side bent portion includes an easily deformable portion.
(9) The living organ expansion device according to any one of (1) to (8), wherein the stent includes an end-side bent multi-layer portion in which side portions of the adjacent one-end bent portions in each annular body overlap. .
(10) The living organ according to any one of (1) to (9), wherein the stent includes an other-end-side bent multi-layer portion in which side portions of the adjacent other-end-side bent portions in each annular body overlap. Expansion device.
(11) The side surface of the bent portion that is the upper layer side in the one end side bent multi-layer portion and / or the other end side bent multi-layer portion is an inclined surface that protrudes from the outer surface side, and the side of the bent portion that is the lower layer side The side organ is a living organ dilator as described in (9) or (10) above, which has an inclined surface from which the inner surface protrudes.
(12) The living organ dilator as described in any one of (1) to (11) above, wherein all the linear components adjacent to each other in the annular body include a multilayer portion where the side portions overlap.

(13) The stent is formed in a substantially tubular body, has a diameter for insertion into a lumen in a living body, and expands when a force spreading in the radial direction from the inside of the stent is applied. The body organ expanding instrument body includes a tube-shaped shaft body portion and a foldable and expandable balloon provided at the distal end portion of the shaft body portion, and the stent includes the balloon in a folded state. The living organ dilating instrument according to any one of (1) to (12), which is mounted so as to be encapsulated and is expanded by expansion of the balloon.
(14) The stent is formed in a substantially cylindrical shape, is compressed in the direction of the central axis when inserted into the living body, expands outward when placed in the living body, and restores the shape before compression. The instrument main body includes a sheath that houses the stent in the distal end portion, and an inner tube that is slidably inserted in the sheath and that discharges the stent from the distal end of the sheath. Thru | or the living organ expansion device in any one of (12).
(15) The total surface area of the linear components of the stent in a state of being attached to the body organ expansion instrument body is the surface area of the cylindrical portion formed by the stent in a state of being attached to the body organ extension body. The living organ dilator according to any one of the above (1) to (14), which is 0.8 to 2.0 times greater than the above.
(16) In the stent, the total surface area of the linear components of the stent at the time of expansion is 1.0 to 2 of the surface area of the exposed linear components of the stent in a state where the stent is attached to the living organ expansion device body. The living organ dilator according to any one of (1) to (15), which is 0.0 times.

A living organ dilator according to the present invention includes a stent having a connecting portion that connects a plurality of annular bodies arranged in the axial direction and the adjacent annular bodies, and a tube-shaped living organ dilator main body to which the stent is attached. A plurality of one-end-side bent portions having apexes on one end side in the axial direction of the stent and a plurality of apexes on the other end side in the axial direction of the stent. The other end-side bent portion, and a linear component connecting the one end-side bent portion and the other end-side bent portion, and the stent is attached to the body organ expansion instrument body. In this embodiment, the side portions of the adjacent linear components in each annular body are provided with overlapping portions, and the connecting portions do not overlap.
As described above, the stent provided in the living organ dilating instrument of the present invention includes a multi-layered portion in which the side portions of the adjacent linear components in the annular body overlap with each other. The diameter of the stent can be made smaller, and since the stent does not overlap at the connecting portion, the stent has flexibility when mounted on the living body expansion device body and placed in the living body, and the stent is layered when expanded. Since the portion expands in the direction in which the portion disappears, the stratified portion is less likely to remain, and the stent exhibits a uniform expansion force during in-vivo placement and can satisfactorily improve the stenosis site.

The living organ dilator according to the present invention will be described using the following preferred embodiments.
FIG. 1 is a front view of a stent used in a living organ expanding device according to an embodiment of the present invention when mounted on a living organ expanding device body. FIG. 2 is an exploded view of the stent of FIG. FIG. 3 is a partially enlarged view of FIG. FIG. 4 is an enlarged partial sectional view taken along line AA in FIG. FIG. 5 is a front view of the stent of FIG. 1 when expanded. FIG. 6 is a development view of the stent of FIG. 1 at the time of expansion.
FIG. 15 is a front view of a living organ dilator according to an embodiment of the present invention. FIG. 16 is an enlarged partial cross-sectional view of the distal end portion of the living organ dilator shown in FIG. FIG. 17 is an explanatory diagram for explaining the operation of the living organ dilator according to the embodiment of the present invention.

A living body dilating instrument 100 according to the present invention includes a stent 1 having a connecting portion 3 that connects a plurality of annular bodies 2 arranged in the axial direction and an adjacent annular body 2, and a tube-shaped living organ expansion apparatus to which the stent 1 is attached. It consists of the instrument body 101.
The annular body 2 of the stent 1 includes a plurality of one end side bent portions 5 having apexes on one end side in the axial direction of the stent, a plurality of other end side bent portions 6 having apexes on the other end side in the axial direction of the stent, It is comprised by the linear component 4 which connects a side bending part and an other end side bending part. The stent 1 includes a multi-layered portion 43 in which the side portions of adjacent linear components 4 in each annular body 2 overlap each other when mounted on the living organ expanding device main body 101, and does not overlap in the connecting portion 3. It has become. The stent 1 is preferably one in which the multilayer portion 43 substantially disappears during expansion, and particularly preferably completely disappears.

In the living body organ dilator 100 of this embodiment, the stent 1 is formed in a substantially tubular body, has a diameter for insertion into a lumen in a living body, and is applied with a force that spreads radially from the inside of the stent 1. The body organ expanding device main body 101 includes a tube-shaped shaft main body 102 and a foldable and expandable balloon 103 provided at the distal end of the shaft main body 102. Is mounted so as to enclose the balloon 103 in a folded state, and is expanded by expansion of the balloon 103.
A stent 1 used in the living organ dilator of this embodiment has a connecting portion 3 that connects a plurality of annular bodies 2 arranged in the axial direction and an adjacent annular body 2. The annular body 2 of the stent 1 includes a plurality of one end side bent portions 5 having apexes on one end side in the axial direction of the stent, a plurality of other end side bent portions 6 having apexes on the other end side in the axial direction of the stent, It has the linear component 4 which connects a side bending part and an other end side bending part.

This stent 1 is formed in a substantially tubular body, has a diameter for insertion into a lumen in a living body, and is expandable when a force that expands radially from the inside of the tubular body is applied, a so-called balloon. It is an expandable stent. The stent of the present invention is not limited to a balloon expandable stent.
As shown in FIGS. 1 to 6, the stent 1 has a configuration in which a plurality of wavy annular bodies 2 are arranged so as to be adjacent in the axial direction and are connected to each other.
Each wavy annular body 2 includes a plurality of one end side bent portions 5 having apexes on one end side in the axial direction of the stent 1 and a plurality of other end side bent portions having apexes on the other end side in the axial direction of the stent 1. 6 and an endless wavy linear body having a linear component 4 connecting the one-end-side bent portion 5 and the other-end-side bent portion 6.
The material for forming the stent 1 is preferably a material having a certain degree of biocompatibility, such as stainless steel, tantalum or tantalum alloy, platinum or platinum alloy, gold or gold alloy, cobalt base alloy, cobalt chromium alloy, titanium alloy, Niobium alloys and the like are conceivable. Moreover, after producing the stent shape, precious metal plating (gold, platinum) may be performed. As stainless steel, SUS316L having the most corrosion resistance is suitable.

As shown in FIGS. 1 to 4, the stent 1 has adjacent linear components in each annular body 2 when mounted on the living organ dilator main body 101 (in other words, when compressed, when reduced in diameter). The multi-layer part 43 with which 4 side parts overlap is provided. In particular, in this embodiment, as shown in FIGS. 3 and 4, the linear component 4 is in a state where the upper layer linear component 41 and the lower layer linear component 42 are alternately arranged, Overlayer portions 43 are formed on both sides of the lower layer linear component 42. In other words, the annular body 2 has a plurality of linear configurations in which the cross-sectional shape in the direction orthogonal to the central axis of the stent 1 has a first trapezoidal cross section that is long on the outer surface side and slightly curved on the inner surface side. An element (upper layer linear component 41) and a plurality of linear components (lower layer linear component 42) having a second trapezoidal cross section that is long on the inner surface side and slightly curved on the inner surface side, and both (Upper layer linear component 41 and lower layer linear component 42) are alternately arranged.
Since such a multi-layered portion 43 is provided, the outer diameter of the stent 1 when it is attached to the living body expansion device main body 101 (in other words, when compressed or reduced in diameter) can be made smaller, and the living body with a smaller diameter can be obtained. It is possible to improve the narrowed part of an organ (for example, a blood vessel). The width of the multi-layered portion 43 varies depending on the size of the stent, the width of the linear component 4, and the like, but is preferably about 0.03 to 0.1 mm.

And as shown in FIG. 4, the side surface 41a of the side part of the linear component 41 used as the upper layer side in the multilayer part 43 becomes the inclined surface which the outer surface side protrudes, and in order to correspond to this, the multilayer part 43, the side surface 42a of the side part of the linear component 42 which is the lower layer side is an inclined surface from which the inner surface side protrudes. For this reason, when the stent 1 is attached to the biological organ dilator main body 101 (in other words, when compressed, when the diameter is reduced), the formation of the multilayer portion 43 where the side portions of the adjacent linear components 4 in each annular body 2 overlap each other. Is certain. In addition, by doing the above, it is easy to eliminate the multi-layered portion 43 at the time of stent expansion.
And as an inclined surface of the side part of said linear component, it is preferable that the extended surface of an inclined surface passes the place near the outer surface of the said linear component from the center axis | shaft of the stent 1. FIG. Moreover, as shown in FIG. 4, it is preferable that the corner | angular parts 41b and 42b of the side part of the linear components 41 and 42 are chamfered.

And in this stent 1, the side part of the adjacent linear component 4 in the annular body 2 is the multilayer part 43 which overlaps over substantially full length. By doing so, the outer diameter of the predetermined length portion of the annular body 2 can be made small. In the stent 1, the adjacent linear components 4 in the annular body 2 are arranged so that the shaft of the stent 1 is attached when the stent 1 is mounted on the living organ dilator main body 101 (in other words, when compressed or contracted). It is almost parallel to.
Moreover, in this stent 1, all the adjacent linear components in the annular body 2 are provided with the multilayer part 43 which a side part overlaps. By doing in this way, the annular body 2 can be made smaller. In addition, although it is preferable that all the adjacent linear components in the annular body 2 include the multilayer portion 43 whose side portions overlap, the present invention is not limited to this, and some of the linear components Only the side portions may overlap to form a multilayer portion. For example, the side portions of the adjacent linear components in the annular body 2 may overlap to form a multilayer portion.

Furthermore, this stent 1 is provided with the one end side bending | flexion multilayer part 5a with which the side part of the adjacent one end side bending part 5 in each annular body 2 overlaps, as shown in FIG. 1 thru | or FIG. Similarly, this stent includes the other-end-side bent multilayer portion 6a in which the side portions of the adjacent other-end-side bent portions 6 in each annular body 2 overlap. As described above, the outer diameter of the entire annular body 2 can be made small by providing the multilayer portion in the bent portion.
In the one-end-side bent multi-layer portion 5a, the side surface of the bent portion 5 that is the upper layer side is an inclined surface that protrudes from the outer surface side, and the side surface of the bent portion 5 that is the lower layer side is an inclined surface that protrudes from the inner surface side. It is preferable. Similarly, the side surface of the bent portion 6 that is the upper layer side in the other-end-side bent multi-layer portion 6a is an inclined surface that protrudes from the outer surface side, and the side surface of the bent portion 6 that is the lower layer side is an inclined surface from which the inner surface side protrudes. It is preferable that By doing in this way, when the stent 1 is attached to the living organ expansion device main body 101 (in other words, at the time of compression, at the time of diameter reduction), the overlapping portion where the side portions of the adjacent bent portions overlap in each annular body 2 is overlapped. Ensure formation. In addition, by doing the above, it becomes easy to eliminate the multi-layered portion at the time of stent expansion. And as an inclined surface of the side part of said bending part, it is preferable that the extended surface of an inclined surface passes a place near the outer surface of the said linear component rather than the center axis | shaft of the stent 1. FIG. Moreover, as shown in FIG. 4, it is preferable that the corner | angular parts 41b and 42b of the side part of the linear components 41 and 42 are chamfered.

And in this stent 1, as shown in FIG. 1 thru | or FIG. 3, in the connection part 3, there is no overlap of a component. For this reason, the stent 1 can be bent in the connecting portion 3 portion, and has sufficient flexibility as a whole even if it includes the multilayer portion 43 in which the side portions of the adjacent linear components 4 overlap.
And this stent 1 will be in the state shown to FIG. 5 and FIG. 6 at the time of expansion, and the multilayer part 43 will lose | disappear. For this reason, since the stent 1 does not include the above-described multi-layered portion at the time of expansion in the in-vivo indwelling state, the entire annular body exhibits a uniform expansion holding force with less hardness.

And the formation form of the multilayer part 43 is not limited to the thing like the stent 1 mentioned above. For example, it may be in the form of the stent 10 shown in FIGS. FIG. 7 is a partially enlarged view of another example of the stent used in the living organ dilator according to the present invention. FIG. 8 is an enlarged partial sectional view taken along line BB in FIG.
In the stent 10 of this example, as shown in FIG. 7 and FIG. 8, the linear component 4 has a state in which one side of the linear component 4 is the upper layer side and the other side is the lower layer side. These are continuous in an annular shape, and multilayer portions 43 are formed on both sides of each linear component 4. In other words, in the stent 10 of this example, the annular body 2 includes a plurality of linear components having a parallelogram-shaped cross section in which the cross-sectional shape in the direction orthogonal to the central axis of the stent 10 is slightly curved toward the inner surface side. It has become a thing.

Since the stent 10 also includes the multilayer portion 43 as described above, the outer diameter when the stent 10 is attached to the living organ dilator main body 101 (in other words, when compressed or contracted) may be reduced. It is possible to improve the narrowed portion of a living organ (for example, blood vessel) having a smaller diameter. The width of the multi-layered portion 43 varies depending on the size of the stent, the width of the linear component 4, and the like, but is preferably about 0.03 to 0.1 mm.
And as shown in FIG. 8, the side surface 4a of the side part of the linear component which becomes the upper layer side in the multilayer part 43 is an inclined surface that the outer surface side protrudes, and the multilayer part 43 is corresponding to this. The side surface 4b of the side part of the linear component that is the lower layer side is an inclined surface from which the inner surface side protrudes. For this reason, when the stent 10 is attached to the living organ expansion device main body 101 (in other words, when compressed, when the diameter is reduced), formation of the multilayer portion 43 in which the side portions of the adjacent linear components 4 in each annular body 2 overlap each other. Is certain. In addition, by doing the above, it is easy to eliminate the multi-layered portion 43 at the time of stent expansion.
And as an inclined surface of the side part of said bending part, it is preferable that the extended surface of an inclined surface passes the place near the outer surface of the said linear component from the center axis | shaft of the stent 10. FIG. Moreover, as shown in FIG. 8, it is preferable that the corner | angular part 4c of the side part of the linear component 4 is chamfered.

And as a stent used for the living organ dilator 100 of the present invention, the one end side bent portion 15 or the other end side bent portion 16 includes an easily deformable portion, as in the stent 20 shown in FIGS. Preferably it is. In particular, like the stent 20 of this example, it is preferable that both the one-end-side bent portion 15 and the other-end-side bent portion 16 are provided with easily deformable portions. FIG. 9 is a developed view of another example of a stent used for the living organ dilating instrument of the present invention during expansion. FIG. 10 is a partially enlarged view of FIG.
As described above, the stent used in the living organ dilator 100 of the present invention includes the multi-layered portion 43 where the side portions of the adjacent linear components 4 in each annular body 2 overlap. For this reason, there is a high possibility that the bent portion has a large amount of deformation when the stent is attached to the living body organ dilator main body 101 (in other words, when compressed, when the diameter is reduced). Therefore, like the stent 20 shown in FIG. 9 and FIG. 10, it is preferable that the one end side bending part 15 and the other end side bending part 16 are provided with an easily deformable part. In this stent 20, as shown in FIG. 10, the linear portions constituting the one end side bent portion 15 and the other end side bent portion 16 are narrower than the other portions, and the inside thereof It has an arc shape having a circular gap and a predetermined size. The arc is preferably 2/3 yen or more. By doing so, bending at the bending portion is facilitated, and adjacent linear structures in the respective annular bodies 2 when the stent 20 is attached to the living organ expansion device main body 101 (in other words, when compressed or contracted). It is easy to form the multi-layer part 43 where the side parts of the element 4 overlap.

The form of the easily deformable portion is not limited to the type in which almost the entire bent portions 15 and 16 are easily deformable portions as in the stent 20 described above. For example, a stent 30 shown in FIG. 11 may be used.
FIG. 11 is a partially enlarged view of a stent of another example of the living organ dilator according to the present invention. In the stent 30 of this example, it is preferable that both the one end side bent portion 25 and the other end side bent portion 26 are provided with easily deformable portions. The one end side bent portion 25 is provided with an easily deformable portion 25a formed by a notch portion. The other end-side bent portion 26 is provided with an easily deformable portion 26a formed by a notch portion.

In addition, the form of the multi-layered portion 43 in the stent used in the living organ dilator 100 is not limited to that described above, and a part of the side portion of the adjacent linear component 4 in each annular body 2 is used. May be formed by overlapping.
FIG. 12 is a development view of another example of the stent used for the living organ dilating instrument of the present invention during expansion. FIG. 13 is a partially enlarged view of FIG. FIG. 14 is a partially enlarged view of the stent shown in FIG. 12 when mounted on the body organ expansion instrument body.
In this stent 40, each annular body 2 includes a bulging portion 44 extending in the circumferential direction of the annular body 2 at the side portion of the linear component 4, and the multilayer portion includes a linear component adjacent to the bulging portion. It is formed by overlapping. In particular, in the stent 40 of this example, the side portion of the adjacent linear component 4 in each annular body 2 includes a bulging portion 44 extending in the circumferential direction of the annular body 2, and the multilayer portion 43 includes the bulging portion 44. Are formed by overlapping a part of each other. In addition, it is not limited to what the bulging part 44 overlaps, for example, the bulging part 44 is provided only in one side part of the linear component 4, and the linear structure to which the bulging part 44 adjoins. It may directly overlap the element.

In this stent 40, the bulging part 44 extended in the circumferential direction of the annular body 2 from the both sides of the adjacent linear component 4 in each annular body 2 is provided. And by providing such a bulging part, the expansion maintenance force of the stenosis part of a stent becomes higher.
And in this stent 40, the bulging part is formed in the substantially center part of the longitudinal direction of a linear component, and is a substantially elliptical thing. The width of the bulging portion at the maximum width portion is preferably about 1.2 to 2 times the width of the linear component 4 at the portion that is not the bulging portion. In this stent 40, bulged portions 44 are formed in all the linear components 4. In addition, although it is preferable that the bulging part 44 has the bulging part 44 formed in all the linear components 4, the linear component 4 which does not have the bulging part 44 may exist.

  As shown in FIG. 14, the stent 40 has a bulging portion extending in the circumferential direction of the annular body 2 when the stent is attached to the living body expansion device main body 101 (in other words, when compressed, when reduced in diameter). A part of 44 overlaps to form a multilayer part 43. And also in the stent 40 of this Example, it is preferable that the side surface of the side part of the bulging part 44 used as the upper layer side in the multilayer part 43 becomes the inclined surface which the outer surface side protrudes, and also in the multilayer part 43 It is preferable that the side surface of the side part of the bulging part 44 used as the lower layer side is an inclined surface from which the inner surface side protrudes.

  And the stent of all the examples mentioned above is provided with the connection part 3 which connects the adjacent wavy-line annular body 2. FIG. A plurality of connecting portions 3 may be provided between adjacent wavy annular bodies. Further, as shown in FIG. 2 and FIG. 6, adjacent wavy-line annular bodies connected by a plurality of connecting portions 3 and adjacent wavy-line annular bodies connected by one connecting portion 3 are alternately arranged. It may be provided. In addition, the axial length of the stent 1 of the connecting portion 3 is preferably about 1.0 mm or less, and particularly preferably 0.1 to 0.4 mm.

For example, after the stent is brought into the state shown in FIG. 5, the stent is mounted by being reduced in diameter on a balloon of an instrument having an expandable balloon. The stent is expanded in diameter from the state of FIG. 1 to the state of FIG. 5 by expanding the balloon.
The diameter of the stent when not expanded is preferably about 0.8 to 1.8 mm, more preferably 0.9 to 1.6 mm. The length of the stent when not expanded is preferably about 8 to 40 mm. Further, the length of one wavy annular body 2 is preferably about 1.0 to 2.5 mm.
Further, the number of wavy annular bodies 2 forming the stent is 12 in the one shown in FIGS. The number of wavy annular bodies 2 varies depending on the length of the stent, preferably 4 to 50, and particularly preferably 10 to 35.
And it is preferable that a stent is produced by removing except a ring body and the part used as the said connection part from a metal pipe. By doing in this way, it becomes a thing with few physical property changes as a whole.

And since the stent used for this invention has a multilayer part as mentioned above, compared with the conventional stent, the stent with respect to the surface area of the cylindrical part which a stent forms in the state with which the biological organ expansion device main body was mounted | worn The total surface area of the linear components is large. The total surface area of the linear components of the stent mounted on the living organ expanding device body is 0.8 to 2.0 of the surface area of the tubular portion formed by the stent mounted on the living organ expanding device body. It is preferable that it is double. In particular, it is preferably 1.2 to 1.8 times. Further, the total surface area of the linear components of the stent at the time of expansion may be 1.0 to 2.0 times the surface area of the exposed linear components of the stent in a state where the stent is attached to the living organ expansion device body. preferable. In particular, it is preferably 1.2 to 1.8 times.
By doing as described above, the stent attached to the body organ expanding instrument body has a sufficient riding-up portion, and also has a high expansion holding force during expansion. In addition, the cylindrical part which the stent of the state with which the biological organ expansion instrument main body in the above-mentioned state forms forms the surface area of the virtual cylindrical body which the external shape of a stent forms. Further, the total surface area of the linear components of the stent in a state where it is mounted on the body organ expansion instrument main body is the area on the front side including the riding part and the part where the surface overlaps with the riding part and the surface is not exposed.

And as a stent used for this invention, it is not limited to the balloon expandable stent mentioned above, A self-expandable stent may be sufficient.
The self-expanding stent is formed in a substantially cylindrical shape, and is compressed in the direction of the central axis when inserted into the living body, and is expanded outwardly and restored to the shape before compression when placed in the living body. As the shape of the self-expanding stent, it is preferable that the same shape as the stent shape of the above-described embodiment, the size, and the like are the same.

A super elastic metal is suitable as a constituent material of the self-expanding stent 203. As the superelastic metal, a superelastic alloy is preferably used. The superelastic alloy here is generally called a shape memory alloy, and exhibits superelasticity at least at a living body temperature (around 37 ° C.). Particularly preferably, a Ti—Ni alloy of 49 to 53 atomic% Ni, a Cu—Zn alloy of 38.5 to 41.5 wt% Zn, and a Cu—Zn—X alloy of 1 to 10 wt% X (X = Be, A super elastic metal body such as Si, Sn, Al, Ga), Ni-Al alloy of 36-38 atomic% Al is preferably used. Particularly preferred is the Ti—Ni alloy described above. Further, a Ti—Ni—X alloy in which a part of the Ti—Ni alloy is substituted with 0.01 to 10.0% X (X = Co, Fe, Mn, Cr, V, Al, Nb, W, B, etc.) Or a Ti—Ni—X alloy (X = Cu, Pb, Zr) in which a part of the Ti—Ni alloy is substituted by 0.01 to 30.0% atoms, and the cold work rate Alternatively, mechanical characteristics can be appropriately changed by selecting conditions for final heat treatment. Further, the mechanical characteristics can be appropriately changed by selecting the cold work rate and / or the final heat treatment conditions using the Ti—Ni—X alloy. The buckling strength (yield stress during loading) of the superelastic alloy used is 5 to 200 kg / mm ² (22 ° C.), more preferably 8 to 150 kg / mm ^2. Restoring stress (yield stress during unloading) ) Is 3 to 180 kg / mm ² (22 ° C.), more preferably 5 to 130 kg / mm ² . Superelasticity here means that even if it is deformed (bending, pulling, compressing) to a region where normal metal is plastically deformed at the operating temperature, it will recover to its almost uncompressed shape without the need for heating after the deformation is released. It means to do.

Next, the vasodilator of the present invention will be described with reference to the embodiments shown in the drawings.
FIG. 15 is a front view of a living organ dilator according to an embodiment of the present invention. FIG. 16 is an enlarged partial cross-sectional view of the distal end portion of the living organ dilator shown in FIG. FIG. 17 is an explanatory diagram for explaining the operation of the living organ dilator according to the embodiment of the present invention.
A vascular dilator 100 according to the present invention includes a stent 1 having a connecting portion 3 that connects a plurality of annular bodies 2 arranged in the axial direction and an adjacent annular body 2, and a tubular biological organ dilator having the stent 1 attached thereto. It consists of a main body 101.

As the stent 1, the stents of all the embodiments described above can be used. The stent used here is a so-called balloon expandable stent that has a diameter for insertion into a lumen in a living body and is expandable when a force that expands radially from the inside of the tubular body is applied. Used.
The living organ expanding instrument main body 101 includes a tube-shaped shaft main body 102 and a foldable and expandable balloon 103 provided at the distal end of the shaft main body 102.
In the living organ dilator 100 of this embodiment, as shown in FIG. 16, the shaft main body 102 has one end opened at the tip of the shaft main body 102 and the other end at the rear end of the shaft main body 102. An opening guide wire lumen 115 is provided.
The living organ expanding instrument main body 101 includes a shaft main body 102 and a stent expansion balloon 103 fixed to the distal end of the shaft main body 102, and the stent 1 is mounted on the balloon 103. The shaft body 102 includes an inner tube 112, an outer tube 113, and a branch hub 110.

  As shown in FIG. 16, the inner tube 112 is a tube body including a guide wire lumen 115 for inserting a guide wire therein. The inner tube 112 has a length of 100 to 2500 mm, more preferably 250 to 2000 mm, and an outer diameter of 0.1 to 1.0 mm, more preferably 0.3 to 0.7 mm, and a wall thickness of 10 to 10. It is 250 micrometers, More preferably, it is 20-100 micrometers. The inner tube 112 is inserted into the outer tube 113, and the tip of the inner tube 112 protrudes from the outer tube 113. A balloon expanding lumen 116 is formed by the outer surface of the inner tube 112 and the inner surface of the outer tube 113, and has a sufficient volume. The outer tube 113 is a tube body in which the inner tube 112 is inserted and the tip is located at a portion slightly retracted from the tip of the inner tube 112.

The outer tube 113 has a length of 100 to 2500 mm, more preferably 250 to 2000 mm, and an outer diameter of 0.5 to 1.5 mm, more preferably 0.7 to 1.1 mm, and a wall thickness of 25 to 25 mm. It is 200 μm, more preferably 50 to 100 μm.
In the living organ dilator 100 of this embodiment, the outer tube 113 is formed by the distal end side outer tube 113a and the main body side outer tube 113b, and both are joined. The distal end side outer tube 113a has a tapered diameter at a portion closer to the distal end than the joint portion with the main body side outer tube 113b, and the distal end side has a smaller diameter than the tapered portion.

The outer diameter at the small diameter portion of the distal end side outer tube 113a is 0.50 to 1.5 mm, preferably 0.60 to 1.1 mm. Further, the base end portion of the distal end side outer tube 113a and the outer diameter of the main body side outer tube 113b are 0.75 to 1.5 mm, preferably 0.9 to 1.1 mm.
The balloon 103 has a front end side joint portion 103a and a rear end side joint portion 103b. The front end side joint portion 103a is fixed at a position slightly rear end side from the front end of the inner tube 112, and the rear end side joint portion 103b. Is fixed to the tip of the outer tube. The balloon 103 communicates with the balloon expansion lumen 116 in the vicinity of the proximal end portion.

  As a material for forming the inner tube 112 and the outer tube 113, a material having a certain degree of flexibility is preferable. For example, polyolefin (for example, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, etc.) Further, thermoplastic resins such as polyvinyl chloride, polyamide elastomer and polyurethane, silicone rubber, latex rubber and the like can be used, preferably the above-mentioned thermoplastic resin, more preferably polyolefin.

As shown in FIG. 16, the balloon 103 is foldable, and can be folded on the outer periphery of the inner tube 112 when not expanded. As shown in FIG. 17, the balloon 103 has an expandable portion that is a cylindrical portion (preferably, a cylindrical portion) having substantially the same diameter so that the attached stent 1 can be expanded. The substantially cylindrical portion may not be a perfect cylinder, but may be a polygonal column. As described above, the balloon 103 is liquid-tightly fixed to the inner tube 112 with the front end side joint portion 103a and the rear end side joint portion 103b to the front end of the outer tube 113 with an adhesive or heat fusion. . Further, in this balloon 103, the space between the expandable portion and the joint portion is formed in a tapered shape.
The balloon 103 forms an expansion space 103 c between the inner surface of the balloon 103 and the outer surface of the inner tube 112. The expansion space 103c communicates with the expansion lumen 116 on the entire periphery at the rear end. In this way, the rear end of the balloon 103 communicates with the expansion lumen having a relatively large volume, so that the expansion fluid can be reliably injected into the balloon from the expansion lumen 116.

As a material for forming the balloon 103, a material having a certain degree of flexibility is preferable. For example, polyolefin (for example, polyethylene, polypropylene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, cross-linked ethylene-vinyl acetate). Copolymer), polyvinyl chloride, polyamide elastomer, polyurethane, polyester (for example, polyethylene terephthalate), thermoplastic resin such as polyarylene sulfide (for example, polyphenylene sulfide), silicone rubber, latex rubber, and the like. In particular, a stretchable material is preferable, and the balloon 103 is preferably biaxially stretched having high strength and expansion force.
As the size of the balloon 103, the outer diameter of the cylindrical portion (expandable portion) when expanded is 2 to 4 mm, preferably 2.5 to 3.5 mm, and the length is 10 to 50 mm, preferably 20-40 mm. Moreover, the outer diameter of the front end side joint portion 103a is 0.9 to 1.5 mm, preferably 1 to 1.3 mm, and the length is 1 to 5 mm, preferably 1 to 1.3 mm. Moreover, the outer diameter of the rear end side joint portion 103b is 1 to 1.6 mm, preferably 1.1 to 1.5 mm, and the length is 1 to 5 mm, preferably 2 to 4 mm.

As shown in FIGS. 16 and 17, the vasodilator 100 has two X-rays fixed to the outer surface of the shaft main body at the positions corresponding to both ends of the cylindrical portion (expandable portion) when expanded. Contrast members 117 and 118 are provided. In addition, it is good also as what has two X-ray contrast contrast members fixed to the outer surface of the shaft main-body part 102 (in this embodiment, the inner pipe | tube 112) of the position which becomes the both ends of the predetermined length of the center part of the stent 1. FIG. Furthermore, it is good also as what provides the single X-ray contrast property member fixed to the outer surface of the shaft main-body part of the position used as the center part of a stent.
The X-ray contrast members 117 and 118 are preferably ring-shaped members having a predetermined length, or those obtained by winding a linear body in a coil shape, and the forming material is, for example, gold, platinum, tungsten, or the like. Those alloys or silver-palladium alloys are suitable.

The stent 1 is attached so as to encapsulate the balloon 103. The stent is manufactured by processing a metal pipe having a smaller diameter than that at the time of stent expansion and an inner diameter larger than the outer diameter of the folded balloon. Then, a balloon is inserted into the manufactured stent, and a uniform force is applied to the outer surface of the stent inward to reduce the diameter, thereby forming a product-state stent. That is, the above stent 1 is completed by compression mounting on the balloon.
A linear rigidity imparting body (not shown) may be inserted between the inner tube 112 and the outer tube 113 (within the balloon expansion lumen 116). The rigidity imparting body prevents extreme bending of the main body 102 of the living organ expanding device 100 at the bent portion without significantly reducing the flexibility of the living organ expanding device 100, and the distal end of the living organ expanding device 100. Easy to push the part. It is preferable that the tip of the rigidity imparting body has a smaller diameter than other parts by a method such as polishing. In addition, it is preferable that the distal end of the small diameter portion of the rigidity imparting body extends to the vicinity of the distal end portion of the main body outer tube 113. The rigidity imparting body is preferably a metal wire, and is preferably an elastic metal such as stainless steel having a wire diameter of 0.05 to 1.50 mm, preferably 0.10 to 1.00 mm, a superelastic alloy, and the like, and particularly preferably. Is a high-strength stainless steel for springs and a superelastic alloy wire.

In the living organ dilator 100 of this embodiment, as shown in FIG. 15, a branch hub 110 is fixed to the proximal end. The branch hub 110 has a guide wire inlet 109 that communicates with the guide wire lumen 115 to form a guide wire port, and communicates with the inner tube hub fixed to the inner tube 112 and the balloon expansion lumen 116, and the injection port 111. And an outer tube hub fixed to the outer tube 113. The outer tube hub and the inner tube hub are fixed to each other. As a material for forming the branch hub 110, a thermoplastic resin such as polycarbonate, polyamide, polysulfone, polyarylate, and methacrylate-butylene-styrene copolymer can be preferably used.
Note that the structure of the living organ dilator is not limited to the above, and may have a guide wire insertion port communicating with the guide wire lumen at an intermediate portion of the living organ dilator.

Next, a vasodilator according to another embodiment of the present invention will be described with reference to an embodiment shown in the drawings.
FIG. 18 is a partially omitted front view of a living organ dilator according to another embodiment of the present invention. FIG. 19 is an enlarged longitudinal sectional view of the vicinity of the distal end portion of the biological organ dilator shown in FIG.
The living organ dilator 200 of this embodiment includes a stent 203 having a connecting portion 3 that connects a plurality of annular bodies 2 arranged in the axial direction and the adjacent annular bodies 2, and a tube-shaped biological organ to which the stent 203 is attached. It consists of an expansion instrument body 201.
This stent 203 is a so-called self-expanding stent that is formed in a substantially cylindrical shape, is compressed in the direction of the central axis when inserted into the living body, and expands outward when in vivo to restore the shape before compression.

Similar to the stent 1 described above, the annular body 2 of the stent 203 includes a plurality of one-end bent portions 5 having apexes on one end side in the axial direction of the stent and a plurality of others having apexes on the other end side in the axial direction of the stent. It is comprised by the end side bending part 6, and the linear component 4 which connects an one end side bending part and the other end side bending part. The stent 1 includes a multi-layer portion 43 in which the side portions of adjacent linear components 4 in each annular body 2 overlap each other when attached to the living organ expansion instrument main body 201, and does not overlap in the connecting portion 3. It has become. Furthermore, the stent 1 is configured such that the multilayer portion 43 disappears during expansion.
In the living organ expanding device 200 of this embodiment, the stent 203 is formed in a substantially cylindrical shape, compressed in the direction of the central axis when inserted into the living body, and expanded outwardly when being placed in the living body to restore the shape before compression. The living body expansion device main body 201 includes a sheath 202 that houses the stent 203 in the distal end portion, and an inner tube 204 that is slidably inserted through the sheath 202 and discharges the stent 200 from the distal end of the sheath 202. With.

As shown in FIG. 18, the living organ expanding device 200 of this embodiment includes a sheath 202, a self-expanding stent 203, and an inner tube 204.
As shown in FIGS. 18 and 19, the sheath 202 is a tubular body, and the front end and the rear end are open. The distal end opening functions as a discharge port of the stent 203 when the stent 203 is placed in a stenosis in the body cavity. The stent 203 is released from the distal end opening, thereby releasing the stress load and expanding and restoring the shape before compression. The distal end portion of the sheath 202 is a stent housing part 222 that houses the stent 203 therein. The sheath 202 includes a side hole 221 provided on the proximal end side with respect to the storage part 222. The side hole 221 is for leading the guide wire to the outside.

The outer diameter of the sheath 202 is preferably about 1.0 to 4.0 mm, and particularly preferably 1.5 to 3.0 mm. Further, the inner diameter of the sheath 202 is preferably about 1.0 to 2.5 mm. The length of the sheath 202 is preferably 300 to 2500 mm, particularly about 300 to 2000 mm.
A sheath hub 206 is fixed to the proximal end portion of the sheath 202 as shown in FIG. The sheath hub 206 includes a sheath hub main body and a valve body (not shown) that is housed in the sheath hub main body and that holds the inner tube 204 in a slidable and liquid-tight manner. The sheath hub 206 includes a side port 261 that branches obliquely rearward from the vicinity of the center of the sheath hub body. The sheath hub 206 is preferably provided with an inner tube locking mechanism that restricts the movement of the inner tube 204.

As shown in FIGS. 18 and 19, the inner tube 204 includes a shaft-shaped inner tube main body 240, a tip 247 provided at the tip of the inner tube main body 240 and protruding from the tip of the sheath 202, and the inner tube And an inner tube hub 207 fixed to the base end portion of the main body 240.
The distal end portion 247 is preferably formed in a tapered shape that protrudes from the distal end of the sheath 202 and gradually decreases in diameter toward the distal end as shown in FIG. By forming in this way, the insertion into the constricted portion is facilitated. In addition, the inner tube 204 is preferably provided with a stopper that is provided on the distal end side of the stent 203 and prevents movement of the sheath in the distal direction. The proximal end of the distal end portion 247 can be brought into contact with the distal end of the sheath 202 and functions as the stopper.

  Further, as shown in FIG. 19, the inner tube 204 includes two projecting portions 243 and 245 for holding the self-expanding stent 203. The protrusions 243 and 245 are preferably annular protrusions. On the proximal end side of the distal end portion 247 of the inner tube 204, a stent holding projection 243 is provided. A stent release protrusion 245 is provided on the proximal side of the stent holding protrusion 243 by a predetermined distance. A stent 203 is disposed between the two protrusions 243 and 245. The outer diameters of these protrusions 243 and 245 are large enough to abut on a compressed stent 203 described later. For this reason, the movement of the stent 203 to the distal end side is restricted by the protruding portion 243, and the movement to the proximal end side is restricted by the protruding portion 245. When the sheath 202 moves to the proximal end side, the stent 203 stays in that position by the release protrusion 245, so that the stent 203 is exposed from the sheath 202, and as a result, is released from the sheath, and the stent is self-expanded. Furthermore, it is preferable that the proximal end side of the stent release protrusion 245 is a tapered portion 246 that gradually decreases in diameter toward the proximal end side, as shown in FIG. Similarly, the proximal end side of the stent holding projection 243 is preferably a tapered portion 244 that gradually decreases in diameter toward the proximal end side, as shown in FIG. By doing so, the protruding portion is prevented from being caught by the distal end of the sheath when the inner tube 204 is released from the sheath of the stent 203 into the sheath 202 again. Moreover, the protrusions 243 and 245 may be formed of different members from an X-ray contrast material. Thereby, the position of the stent can be accurately grasped under X-ray contrast, and the procedure becomes easier.

As shown in FIG. 19, the inner tube 204 has a lumen 241 extending from the distal end to at least the proximal end side of the stent accommodating portion 222 of the sheath 202, and an inner tube side hole 242 communicating with the lumen 241 on the proximal end side from the stent accommodating portion. And. In the living organ dilator 200 of this embodiment, the lumen 241 terminates at the site where the side hole 242 is formed. The lumen 241 is for inserting one end of a guide wire from the distal end of the living organ dilator 200, partially passing through the inner tube, and then leading out from the side surface of the inner tube. The inner tube side hole 242 is located slightly on the distal end side of the living organ dilator 200 from the sheath side hole 221. The center of the inner tube side hole 242 is preferably 0.5 to 10 mm from the center of the sheath side hole 221.
Note that the living organ dilator is not limited to the above-described type, and the lumen 241 may extend to the proximal end of the inner tube. In this case, the side hole 221 of the sheath becomes unnecessary.
The inner tube 204 penetrates through the sheath 202 and protrudes from the rear end opening of the sheath 202. As shown in FIG. 18, an inner tube hub 207 is fixed to the proximal end portion of the inner tube 204.

FIG. 1 is a front view of a stent used in a living organ expanding device according to an embodiment of the present invention when mounted on a living organ expanding device body. FIG. 2 is an exploded view of the stent of FIG. FIG. 3 is a partially enlarged view of FIG. FIG. 4 is an enlarged partial sectional view taken along line AA in FIG. FIG. 5 is a front view of the stent of FIG. 1 when expanded. FIG. 6 is a development view of the stent of FIG. 1 at the time of expansion. FIG. 7 is a partially enlarged view of another example of the stent used in the living organ dilator according to the present invention. FIG. 8 is an enlarged partial sectional view taken along line BB in FIG. FIG. 9 is a developed view of another example of a stent used for the living organ dilating instrument of the present invention during expansion. FIG. 10 is a partially enlarged view of FIG. FIG. 11 is a partially enlarged view of a stent of another example of the living organ dilator according to the present invention. FIG. 12 is a development view of another example of the stent used for the living organ dilating instrument of the present invention during expansion. FIG. 13 is a partially enlarged view of FIG. FIG. 14 is a partially enlarged view of the stent shown in FIG. 12 when mounted on the body organ expansion instrument body. FIG. 15 is a front view of a living organ dilator according to an embodiment of the present invention. FIG. 16 is an enlarged partial cross-sectional view of the distal end portion of the living organ dilator shown in FIG. FIG. 17 is an explanatory diagram for explaining the operation of the living organ dilator according to the embodiment of the present invention. FIG. 18 is a partially omitted front view of a living organ dilator according to another embodiment of the present invention. FIG. 19 is an enlarged longitudinal sectional view of the vicinity of the distal end portion of the biological organ dilator shown in FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Stent 100 Biological organ dilator 2 Ring body 3 Connection part 4 Linear component 43 Multilayer part

Claims (16)

A biological organ expansion device comprising a stent having a connecting portion that connects a plurality of annular bodies arranged in the axial direction and adjacent annular bodies, and a tube-shaped biological organ expansion instrument main body to which the stent is attached,
The annular body of the stent includes a plurality of one end side bent portions having apexes on one end side in the axial direction of the stent, a plurality of other end side bent portions having apexes on the other end side in the axial direction of the stent, It is constituted by a linear component that connects the one end side bent portion and the other end side bent portion,
The stent includes a multi-layered portion in which side portions of adjacent linear components in each annular body overlap each other when mounted on the body organ expansion instrument body, and does not overlap in the connecting portion. Living organ expansion device. The side surface of the side of the linear component that is the upper layer side in the multilayer portion is an inclined surface that protrudes from the outer surface side, and the side surface of the side of the linear component that is the lower layer side in the multilayer portion is 2. The living organ dilator according to claim 1, wherein the living body dilator is an inclined surface on which the inner surface side protrudes. The annular body has a plurality of linear components having a first trapezoidal cross section in which a cross-sectional shape in a direction orthogonal to the central axis of the stent is long on the outer surface side and slightly curved on the inner surface side, and the inner surface side is long and 3. The living organ dilator according to claim 1, further comprising a plurality of linear components having a second trapezoidal cross section slightly curved toward the inner surface side, wherein both are alternately arranged. . The said annular body is provided with the some linear component which has the parallelogram-shaped cross section in which the cross-sectional shape to the direction orthogonal to the center axis | shaft of the said stent curved slightly to the inner surface side. Biological organ dilator. The living organ expansion device according to any one of claims 1 to 4, wherein the multi-layer portion disappears when the stent is expanded. The living organ dilator according to any one of claims 1 to 5, wherein the side portions of the adjacent linear components in the annular body are layered portions that overlap substantially over the entire length. The said annular body is provided with the bulging part extended in the circumferential direction of the said annular body in the side part of the said linear component, The said multilayer part is formed when this bulging part overlaps. A living organ dilator according to any one of the above. The living organ dilator according to any one of claims 1 to 7, wherein the one end side bent portion and / or the other end side bent portion includes an easily deformable portion. The living organ expansion device according to any one of claims 1 to 8, wherein the stent includes an end-side bent multi-layer portion in which side portions of the adjacent one-end bent portions in each annular body overlap. The living organ expansion device according to any one of claims 1 to 9, wherein the stent includes an other-end-side bent multi-layer portion in which side portions of the other-end-side bent portions adjacent to each other in the annular body overlap each other. The side surface of the bent portion that is the upper layer side in the one end side bent multi-layer portion and / or the other end side bent multi-layer portion is an inclined surface that protrudes from the outer surface side, and the side surface of the bent portion that is the lower layer side is The living organ dilator according to claim 9 or 10, wherein the inner surface side is an inclined surface protruding. The living organ dilator according to any one of claims 1 to 11, wherein all the linear components adjacent to each other in the annular body include a multi-layered portion in which the side portions overlap. The stent is formed in a substantially tubular body, has a diameter for insertion into a lumen in a living body, and expands when a force spreading in a radial direction from the inside of the stent is applied. The organ dilator main body includes a tube-shaped shaft main body and a foldable and expandable balloon provided at the distal end of the shaft main body, and the stent encloses the balloon in a folded state. The biological organ dilator according to any one of claims 1 to 12, which is mounted as described above and is expanded by expansion of the balloon. The stent is formed in a substantially cylindrical shape, is compressed in the direction of the central axis when inserted into a living body, expands outward when placed in the living body, and restores the shape before compression. The sheath according to any one of claims 1 to 12, further comprising: a sheath that houses the stent in a distal end portion; and an inner tube that is slidably inserted through the sheath and that discharges the stent from the distal end of the sheath. A biological organ dilator according to claim 1. The total surface area of the linear components of the stent in the state of being attached to the body organ expansion instrument body is 0. 0 of the surface area of the cylindrical portion formed by the stent in the state of being attached to the body organ extension instrument body. The living organ dilator according to any one of claims 1 to 14, which is 8 to 2.0 times. In the stent, the total surface area of the linear components of the stent at the time of expansion is 1.0 to 2.0 times the surface area of the exposed linear components of the stent in a state where the stent is mounted on the living body expansion device body. The living organ dilator according to any one of claims 1 to 15.

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