JP4373456B2 - In vivo indwelling stent and biological organ dilator - Google Patents

Description

  The present invention relates to an in-vivo indwelling stent and a biological organ dilator used to improve a stenosis or occlusion in a biological lumen such as a blood vessel, a bile duct, a trachea, an esophagus, or a urethra.

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 closely adhered to and 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.
The majority of stents used in the treatment of the internal vascular system, particularly coronary arteries, are balloon-expanded. And as a stent, in order to cope with more cases, a flexible structure is required in the axial direction.

The stent needs to be deformed about 2-3 times in diameter. In the present stent using a metal material, in order to enable the above-mentioned deformation, a structure bent along the circumferential direction is provided, and the diameter of the stent is expanded / contracted by expanding / contracting the bent portion. There is. Furthermore, in order to have flexibility perpendicular to the axial direction, it is necessary that the portion connecting the structure portions capable of expanding the diameter has a degree of freedom in bending. That is, it is necessary to design the connecting portion itself to have flexibility or to reduce the number of connecting portions as much as possible. However, when the connecting portion itself is flexible, the structure is easy to extend in the axial direction. Further, if the number of connecting portions is too small or the arrangement positions are biased, the direction of the flexibility is generated, or the structure is weak against pulling in the axial direction. Conversely, increasing the number of connecting portions increases the strength in the axial direction but decreases flexibility. As a result, it is necessary to arrange an appropriate number of connecting portions in a balanced manner.
An object of the present invention is to provide a stent for in-vivo placement that has flexibility in a direction perpendicular to the axial direction and that can retain the tubular shape of the entire stent against axial expansion and contraction. .

To achieve the above purpose,
(1) A stent that is formed into 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, The stent is annularly formed by a first corrugated annular body formed in an annular shape by corrugated elements and corrugated elements arranged in the axial direction of the stent so that a peak portion is close to a valley portion of the first corrugated annular body. An annular unit comprising the formed second wavy annular body, and a plurality of connecting portions that connect the valleys of the first wavy annular body and the crests of the second wavy annular body is an axial direction of the stent. A plurality of arranged, and provided with a connecting portion for connecting adjacent annular units at the connecting portion forming portion,
At least one of the plurality of connection portions of the annular unit is an integrated portion in which a valley portion of the first wavy annular body and a peak portion of the second wavy annular body are integrated, The connecting portion is a thin line connecting portion, and the connecting portions are provided between two adjacent annular units and at positions facing each other, and further, only two are connected between the adjacent annular units. One of the parts is for connecting the integrated parts of the adjacent annular units, and the other connecting part is for connecting the thin line-like connection part forming sites of the adjacent annular units. And the said connection part adjacent to the axial direction of the said stent is a stent for in-vivo indwelling in which it shifts | deviates a predetermined angle with respect to the central axis of the said stent, and does not continue in the axial direction of a stent.

( 2 ) In the above (1), the connecting portion is inclined at a predetermined angle with respect to the central axis of the stent, and the connecting portions adjacent in the axial direction of the stent have different inclination directions. It is preferable.
(3) In the above (1) or (2), it is preferable that the two connecting portions are arranged such that the two helical intermittently.
In (4) above (1) or (2), the connecting portion adjacent to each other in the axial direction of the stent, with shifted about 60 degrees with respect to the central axis of the stent, the spirally the connecting portion is intermittently It is preferable that they are arranged as described above.

(5) In any one of the above (1) to (4), it is preferable that a wave-shaped end portion of an adjacent annular unit enters a space formed between adjacent wave-shaped elements of the annular unit.

In addition, those that achieve the above objectives
( 6 ) A tubular shaft main body, a foldable and expandable balloon provided at the distal end of the shaft main body, and a balloon mounted on the balloon so as to enclose the balloon in a folded state. A biological organ dilating device comprising a stent that is expanded by expansion, wherein the stent is the stent according to any one of (1) to ( 5 ) above.

The stent for in-vivo placement of the present invention 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 spreading in the radial direction from the inside of the tubular body is applied. The stent is arranged in the axial direction of the stent so that the peak portion is close to the first corrugated annular body formed in an annular shape by the corrugated elements and the valley portion of the first corrugated annular body. A second corrugated annular body formed in an annular shape by the corrugated element, and a plurality of connecting portions that connect the valley portion of the first corrugated annular body and the peak portion of the second corrugated annular body. A plurality of annular units are arranged in the axial direction of the stent, and the adjacent annular units are connected at the connecting portion forming portion, and the connecting portion is not continuous in the axial direction of the stent, and the connecting portions are adjacent to each other. Multiple and facing positions between annular units Properly it is provided to be equiangularly arranged substantially to the center axis of the stent.
For this reason, the stent of this invention has the softness | flexibility with respect to a direction perpendicular | vertical to an axial direction, and can hold | maintain the cylindrical shape of the whole stent favorably with respect to expansion-contraction of an axial direction.
In addition, the in-vivo indwelling stent of the present invention is formed into a substantially tubular body, has a diameter for insertion into a living body lumen, and is applied with a force that spreads radially from the inside of the tubular body. An expandable stent comprising a plurality of substantially polygonal linear bodies having a plurality of linear bends and openings that expand when the radial spreading force is applied. A plurality of annular units connected in the axial direction of the stent, and a connecting portion that connects adjacent annular units at the connecting portion and does not continue in the axial direction of the stent; Are provided so as to be arranged at an approximately equiangular position with respect to the central axis of a plurality of and facing positions between adjacent annular units or the stent.
For this reason, the stent of this invention has the softness | flexibility with respect to a direction perpendicular | vertical to an axial direction, and can hold | maintain the cylindrical shape of the whole stent favorably with respect to expansion-contraction of an axial direction.

The stent of the present invention will be described with reference to the embodiments shown in the drawings.
FIG. 1 is a front view of an embodiment of the stent of the present invention. FIG. 2 is a partially enlarged view of the stent shown in FIG. FIG. 3 is a development view of the stent shown in FIG. 1 before expansion.
The stent 1 of this embodiment is a stent that is formed into a substantially tubular body, has a diameter for insertion into a lumen in a living body, and is expandable when a force that extends radially from the inside of the tubular body is applied. is there. The stent 1 includes a first corrugated annular body 12a formed in an annular shape by corrugated elements having a large number of bent portions 5a, and an axis of the stent 1 so that a peak portion is close to a trough of the first corrugated annular body 12a. Second wave-like annular body 12b formed in a ring shape by wave-like elements arranged in the direction and having linear bent part 5a, and valleys of first wave-like annular body 12a and peaks of second wave-like annular body 12b The annular unit 4 is composed of a plurality of connection parts 6 that connect the parts, and a plurality of the annular units 4 are arranged in the axial direction of the stent 1, and adjacent annular units are connected at a connection part forming site. The connecting part 7 is provided. Furthermore, the connection part 7 is provided so that it may become a substantially equiangular arrangement | positioning with respect to the center axis | shaft of multiple or opposing positions between the adjacent annular units 4, or a stent.

The stent 1 is a so-called balloon expandable stent.
As shown in FIGS. 1 to 3, the stent 1 has a plurality of annular units 4 arranged so as to be substantially linear in the axial direction of the stent 1, and corrugated elements (corrugated annular bodies) of adjacent annular units. 12b and 12a) are provided with a connecting part 7 for connecting the connecting part 6 at the site of formation. In other words, the stent 1 is a tubular body configured by connecting a large number of annular units 4 by connecting portions 7.
The annular units 12a and 12b of the stent 1 have six peaks and valleys having substantially the same pitch as shown in FIG. 1 and FIG. Yes. In addition, 4-7 are suitable for the number of the peaks (or valleys) of the annular unit. And the 2nd wavelike annular body 12b arrange | positioned in an axial direction so that a peak part may adjoin the valley part of the 1st wavelike annular body 12a, and the trough part of the 1st wavelike annular body, and the 2nd wavelike annular shape The ridges of the body are connected by a plurality of short connecting portions 6 to constitute one annular unit 4. In this embodiment, all the troughs of the first wavy annular body 12a and all the crests of the second wavy annular body 12b are connected by the connecting parts 6, and there are six annular units 4 ( It is provided with connecting portions 6 of the number of peaks or valleys of the annular unit.

And the cyclic | annular unit 4 comprised as mentioned above is equipped with the connection part 7 which connects a plurality of (in this example, 12 pieces) in the axial direction of the stent 1, and connects an adjacent cyclic | annular unit, Thereby, the cylindrical stent 1 is formed. And the connection part 7 is provided so that the adjacent annular unit 4 may be connected in multiple places. The number of connecting portions provided between two adjacent annular units is preferably 2 to 4. Furthermore, the connection part 7 is arrange | positioned so that it may not continue with the adjacent connection part. In the stent 1, two connecting portions 7 are provided between adjacent annular units 4 as shown in FIGS. 1 to 3. That is, the adjacent annular units 4 are connected at two locations.
Then, at least one of the plurality of connecting portions of the annular unit 4 is an integrated portion 4a in which the valley portion of the first wavy annular body 12a and the peak portion of the second wavy annular body 12b are integrated. ing. The other connecting portions 6 are thin wire connecting portions. And the at least 1 connection part 7a of the connection part provided between the cyclic | annular units has connected the integrated part 4a of the adjacent cyclic | annular unit 4 mutually. Furthermore, the other connection part 7b has connected the formation site | part of the thin wire | line connection part 6 of the adjacent cyclic | annular unit 4 mutually. That is, in the stent of this embodiment, the adjacent annular units are formed by the integrated portion 4a in which the valleys of the first wavy annular body 12a and the crests of the second wavy annular body 12b included in each annular unit are integrated. Since they are connected, the units 4 have sufficient connection strength. Further, the adjacent annular units include another (second) connecting portion 7b that connects the forming portions of the thin line connecting portions 6 to each other. For this reason, the extension of the stent after in-vivo placement can be suppressed, and since it is not a connection in the integrated portion, it does not cause a bending failure.

  The plurality of connecting portions 7 that connect the annular units 4 are inclined at a predetermined angle with respect to the central axis of the stent 1. In other words, in a state where the stent is cut and deployed in the longitudinal direction parallel to the central axis of the stent, the connecting portion is inclined at a predetermined angle with respect to the longitudinal direction of the stent. Furthermore, in the stent 1 of the embodiment shown in the drawings, the connecting portions that connect two identical adjacent annular units are inclined in the same direction and at substantially the same angle. Further, in the stent 1 of this embodiment, the connecting portions adjacent to each other in the axial direction of the stent have different inclination directions. Furthermore, the connection part 7 is arrange | positioned so that it may not continue with the adjacent connection part. Further, the connecting portion 7 (7a, 7b), the connecting portion 7 (7a, 7b) and the connecting portion 7 (7a, 7b) adjacent in the axial direction of the stent 1 are set at a predetermined angle with respect to the central axis of the stent 1. By shifting, the connecting portions 7 (7a, 7b) are arranged so as to be intermittent. That is, the plurality of connecting portions 7a and 7b and the plurality of connecting portions 7a and 7b and the plurality of connecting portions 7a and 7b adjacent in the axial direction of the stent are at a predetermined angle with respect to the central axis of the stent (the implementation shown in FIG. 3). In the example, they are arranged so as to be shifted from each other by about 60 degrees, whereby the connecting portions 7a and 7b are arranged so as to form a plurality of intermittent (two) spirals.

Thus, in the stent 1, as shown in FIG. 3, the connecting portions 7a and 7b are not continuous with respect to the axial direction of the stent and are arranged in two spiral shapes. The connecting portions at positions adjacent to the direction have different inclination directions. Moreover, the integrated part is the state arrange | positioned at one spiral.
As a result, the stent can be deformed satisfactorily without having a bending directionality as a whole. Not having a bending directionality means having no easy deformation direction and no difficult deformation direction. By making the connecting portion not continuous in the axial direction of the stent, the load when one annular unit 4 changes so as to follow the deformation of the blood vessel directly (or straight) to the annular units 4 that are not adjacent to each other. Transmission) and an independent expansion function of each annular unit is exhibited. Furthermore, if the arrangement of the connecting portions is spiral when viewed from the entirety of the stent 1, it is less likely to be affected by annular units that are not adjacent to each other.

  Furthermore, in this stent 1, it is preferable that the apex part of the bending part 5a of the corrugated annular body of an adjacent annular unit has penetrated into the space formed between the adjacent bending parts of one annular unit. By doing so, the stent 1 is in a state where the wavy annular body partially overlaps when viewed in the axial direction of the stent 1. When the stent 1 is expanded, even if individual components are shortened in the axial direction of the stent 1, there is little increase in the gap on the side surface of the stent 1, the stenosis of the blood vessel can be expanded more reliably, and the lesion site Can be pressed without gaps.

  The stent 1 preferably has a non-expanded diameter of about 0.8 to 1.8 mm, and more preferably 0.9 to 1.4 mm. The length of the stent 1 when not expanded is preferably about 9 to 40 mm. In addition, the length of one wavy annular body 12a, 12b is preferably about 0.7 to 2.0 mm, and the length of one annular unit is preferably about 1.5 to 4.0 mm. In particular, 2.0 to 3.0 mm is more preferable. Further, the number of peaks (in other words, the number of valleys) of one wavy annular body 12a, 12b is preferably 4-8, and particularly preferably 5-7. In addition, the length of the thin wire connection portion 6 is preferably about 0.01 to 0.5 mm. Moreover, the width | variety of a thin wire | line connection part is 0.02-0.04 mm, More preferably, it is 0.025-0.035 mm, when making it fractureable. Moreover, the width | variety of a thin wire | line connection part is 0.06-0.15 mm, More preferably, it is 0.08-0.13 mm, when not making it fracture. And the width | variety of an integrated part is 0.06-0.15 mm, More preferably, it is 0.08-0.13 mm.

  The number of annular units is preferably 3-50. Moreover, 0.5-1 mm is suitable for the length with which the component (annular unit) of an adjacent annular unit overlaps with the axial direction of the stent 1. FIG. Moreover, 1.3-2.5 mm is suitable for the distance between centers between annular units. The length of the connecting portion 7 is preferably 1.4 to 2.7 mm. Furthermore, the inclination angle of the connecting portion with respect to the central axis of the stent 1 (inclination angle with respect to the longitudinal direction when viewed in a developed view) is preferably about 0 ° to 45 °, and particularly preferably 5 ° to 25 °. In addition, the diameter of the stent 1 during molding (before compression) is preferably about 1.5 to 3.5 mm, and more preferably 2.0 to 3.0 mm. Further, the thickness of the stent 1 is preferably about 0.05 to 0.15 mm, particularly preferably 0.08 to 0.12 mm, and the width of the wavy element is 0.07 to 0.15 mm. The degree is preferable, and 0.08 to 0.13 mm is particularly preferable.

  In addition, the stent 1 of the Example mentioned above is a type with which the adjacent annular units are connected by two connection parts. For this reason, the connection part is arrange | positioned in the position facing the center axis | shaft of a stent. However, it is not limited to this Example, You may provide 3-4 (2-4 if said 2 is included) between adjacent annular units. In this case, the connecting portions are provided so as to be arranged at substantially equal angles with respect to the central axis of the stent. That is, when three connecting portions are provided between adjacent annular units, the arrangement is about 120 degrees, and when four connecting portions are provided, the arrangement is about 90 degrees. In addition, even when three or more connecting portions are provided between adjacent annular units as described above, it is preferable that one annular unit includes only one integrated portion. That is, it is preferable that only one connecting portion connects the adjacent integrated portions of the annular units, and the other two or more connecting portions connect the thin line connecting portion forming portions.

  The material for forming the stent 1 is preferably a material having a certain degree of biocompatibility. For example, stainless steel, tantalum or a tantalum alloy, platinum or a platinum alloy, gold or a gold alloy, a cobalt base alloy, or the like can be considered. 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.

  The stent 1 is preferably chamfered. The chamfering method of the stent 1 can be performed by forming the stent into a final shape and then performing chemical polishing, electrolytic polishing or mechanical polishing. The chemical polishing is preferably performed by dipping in a stainless chemical polishing solution. The stainless steel chemical polishing liquid is not particularly limited as long as it can dissolve stainless steel. For example, a mixed liquid composed of hydrochloric acid and nitric acid is used as a basic component, and an organic sulfur compound for adjusting the dissolution rate, smoothing, and imparting gloss. And those to which a surfactant is added are preferred.

  Furthermore, it is preferable to anneal after producing the final shape of the stent 1. By performing the annealing, the flexibility and plasticity of the entire stent are improved, and the indwellability in the bent blood vessel is improved. Compared to the case where annealing is not performed, the force to restore the shape before expansion after the stent 1 is expanded, in particular, the force to return to the linear shape that is manifested when expanding at a bent blood vessel site, The physical stimulation applied to the bent inner wall of the blood vessel is reduced, and the factor of restenosis can be reduced. Annealing is performed by heating to 900 to 1200 ° C. in an inert gas atmosphere (for example, a mixed gas of nitrogen and hydrogen) and then slowly cooling so that an oxide film is not formed on the stent surface. preferable.

Next, a stent according to another embodiment of the present invention will be described with reference to the drawings.
FIG. 4 is a front view of an embodiment of a stent according to another embodiment of the present invention. FIG. 5 is a partially enlarged view of the stent shown in FIG. FIG. 6 is a development view of the stent shown in FIG. 4.
The stent 10 of this embodiment is a stent that 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 spreading radially from the inside of the tubular body is applied. is there. The stent 10 has an annular shape in which a plurality of linear bent portions 13 that expand when a force spreading in the radial direction is applied and a plurality of substantially polygonal linear bodies 13 having openings are connected by a plurality of connecting portions 16 so as to form an annular shape. A plurality of units 14 are arranged in the axial direction of the stent, and the adjacent annular units 14 are connected to each other at the connecting portion, and the connecting portion 15 is not continuous in the axial direction of the stent. They are provided so as to be arranged at a substantially equal angle with respect to a plurality of opposed positions or the central axis of the stent.

This stent is a so-called balloon expandable stent.
Like the stent of this embodiment, it is preferable that the substantially polygonal linear body 13 has a long collapsed shape in the axial direction of the stent. Further, as in the stent of this embodiment, the substantially polygonal linear body 13 positioned at both ends of the stent preferably has a substantially semi-elliptical shape at the outer portion. Further, as in the stent of this embodiment, in the space formed between the bent portions 11a of the adjacent substantially polygonal linear bodies 13 of the annular units, the substantially polygonal linear bodies of the other adjacent annular units 14 are formed. It is preferable that the apex part of 13 bending parts 11a has penetrate | invaded.

  As shown in FIG. 6, which is a development view of FIGS. 4, 5 and 4, the stent 10 is substantially polygonal linear body 13 which is long in the axial direction of the stent 10 and has a linear bent portion 11a and a central opening. Are arranged on a substantially circumference at an approximately equiangular arrangement with respect to the central axis of the stent, and between the adjacent portions (side portions) in the circumferential direction of the substantially polygonal linear body 13 at the connection portion 16. A plurality of annular units 14 are arranged in the axial direction of the stent 10. Furthermore, the connecting part 16 of one annular unit 14 and the connecting part 16 of the adjacent annular unit 14 are connected by at least two places by the connecting part 15. In other words, the stent 10 is a tubular body configured by connecting a large number of annular units 14 by connecting portions 15.

  In this embodiment, the annular unit 14 has six substantially polygonal linear bodies 13 arranged at substantially equal angular intervals. One substantially polygonal linear body 13 is formed in a substantially rhombus shape that is long in the axial direction of the stent 10, and the center thereof opens in a substantially rhombus shape corresponding to the shape of the substantially polygonal linear body 13. Both end portions in the axial direction are linear bent portions 11a. Thus, each substantially polygonal linear body 13 is a shape that forms an independent closed system, in other words, the substantially polygonal linear body 13 is a ring-shaped element that opens on the side surface of the stent 10. Since the substantially polygonal linear body 13 has such a shape, it exerts a strong expansion holding force. Further, each substantially polygonal linear body 13 is curved in the circumferential direction so that the whole is substantially equidistant from the central axis of the stent 10.

The substantially polygonal linear body 13 is connected by a short connecting portion 16 between the center of the axial side portion of the stent 10 and the center of the axial side portion of another substantially polygonal linear body 13 adjacent in the radial direction. Has been. That is, the connection part 16 connects each substantially polygonal linear body 13 in the circumferential direction. Since the connection portion 16 does not substantially change even when the stent 10 is expanded, the force at the time of expansion is likely to be applied to the center of each substantially polygonal linear body 13, and each substantially polygonal linear body 13 is uniform. Expansion (deformation) is possible.
The number of the substantially polygonal linear bodies 13 is not limited to six, and 4-8 are suitable. In addition, the shape of the substantially polygonal linear body 13 is preferably a polygonal shape having apexes facing the axial direction of the stent, and may be particularly a rhombus, a hexagon, an octagon, or the like. Preferably, it has a substantially rhombus shape from the stability of deformation during stent expansion.

The connecting portion 16 of the annular unit 14 and the connecting portion 16 of the adjacent annular unit 14 are relatively long (longer than the connecting portion) and are connected by a connecting portion 15 formed parallel to the axial direction of the stent 10. Yes. Specifically, the annular unit 14 and the adjacent annular unit 14 are connected by a connecting portion 15 that connects between the connecting portions 16.
These connecting portions 15 do not substantially change even when the stent 10 is expanded. Since the connecting portion 15 and the connecting portion 16 are not substantially changed by the expansion of the stent 10, the entire length of the entire stent 10 hardly changes before and after the expansion, and the stent may be extremely shortened after the expansion. Absent. In other words, the connecting portion 16 for connecting the expansion element does not move in the axial direction even when the stent is expanded, and the connecting portions are connected by the connecting portion 15 parallel to the axis, so that the entire length of the stent is almost the same. It is not shortened.
The connecting portion 15 is provided so as to connect a plurality of adjacent annular units 14. The number of connecting portions provided between two adjacent annular units is preferably 2 to 3, particularly preferably 2. Furthermore, the connection part 15 is arrange | positioned so that it may not continue with the connection part adjacent to an axial direction, and direction (angle) is shifted | deviated and arrange | positioned.

  The plurality of connecting portions that connect the annular units are inclined at a predetermined angle with respect to the central axis of the stent 10. In other words, in a state where the stent is cut and deployed in the longitudinal direction parallel to the central axis of the stent, the connecting portion is inclined at a predetermined angle with respect to the longitudinal direction of the stent. And in the stent 10 of this Example, the connection part which connects the same adjacent cyclic | annular unit inclines in the same direction. Furthermore, in the stent 10 of the embodiment shown in the drawings, the connecting portions that connect the same adjacent annular units are inclined in the same direction and at substantially the same angle. Further, the connecting portions adjacent to each other in the axial direction of the stent have different inclination directions. Furthermore, the connection part 15 is arrange | positioned so that it may not continue with the adjacent connection part. Further, the connecting portion 15 and the connecting portion 15 adjacent to the connecting portion 15 in the axial direction of the stent 1 are shifted in a predetermined angle with respect to the central axis of the stent 10 so that the connecting portion 15 is in a spiral shape. Is arranged. That is, the plurality of connecting portions 15 and the plurality of connecting portions 15 and the plurality of connecting portions 15 adjacent to each other in the axial direction of the stent have a predetermined angle with respect to the central axis of the stent (in the embodiment shown in FIG. 6, about 60 degrees). ) So that the connecting portions 15 are arranged in a plurality (two) of intermittent spirals.

  Thus, in the stent 10, as shown in FIG. 6, the connecting portion 15 is not continuous with respect to the axial direction of the stent and is arranged in two spiral shapes, and further in the axial direction. On the other hand, the connecting portions at adjacent positions have different inclination directions. As a result, the stent can be deformed satisfactorily without having a bending directionality as a whole. Not having a bending directionality means having no easy deformation direction and no difficult deformation direction. By making the connecting portion not continuous in the axial direction of the stent, the load when one annular unit 14 changes so as to follow the deformation of the blood vessel directly (or linearly) to the annular units 14 that are not adjacent to each other. Transmission) and an independent expansion function of each annular unit is exhibited. Furthermore, if the arrangement of the connecting portions is spiral when viewed from the entire stent 10, it is less likely to be affected by the annular units that are not adjacent to each other.

Further, the outer portions 13b of the substantially polygonal linear bodies 13 located at both ends of the stent 10 are substantially semi-elliptical. In this way, the expansion force at the end can be made sufficient, and damage to the indwelling blood vessel inner wall and the balloon can be reduced. Further, all the substantially polygonal linear bodies 13 are curved in the circumferential direction so that the whole is substantially equidistant from the central axis of the stent.
Further, in this stent 10, the space formed between the bent portions of the two adjacent substantially polygonal linear bodies 13 of the annular unit 14 has a bent portion of the substantially polygonal linear body 13 of the adjacent annular unit 14. It is preferable that the vertex part of 11a has penetrate | invaded. By doing so, in the stent 10, the annular unit is partially overlapped when viewed in the axial direction of the stent. When the stent 10 is expanded, even if each of the substantially polygonal linear bodies 13 is shortened in the axial direction of the stent 10, there is little increase in the gap on the side surface of the stent 10, and the stenosis of the blood vessel can be expanded more reliably. And the maintenance is also higher.

  The stent 10 preferably has a non-expanded diameter of about 0.6 to 1.8 mm, and more preferably 0.8 to 1.6 mm. Further, the length of one annular unit, in other words, the axial length of one substantially polygonal linear body is preferably about 1.5 to 4.0 mm, and particularly 2.0 to 3. 0 mm is more preferable. Further, the number of cyclic units is 3 to 10, preferably 3 to 8. The thickness of the annular unit at the center of the stent 10 is preferably about 0.05 to 0.12 mm, and particularly preferably 0.06 to 0.10 mm. The thickness of the stent is preferably about 0.05 to 0.09 mm. Further, the diameter of the stent 10 at the time of molding (before compression) is preferably about 1.5 to 3.5 mm, and more preferably 2.0 to 3.0 mm.

In addition, in the stent 10 of the above-described embodiment, the adjacent annular units are of a type connected by two connecting portions. For this reason, the connecting portions are arranged at positions facing the central axis of the stent. Has been. However, the present invention is not limited to this embodiment, and 3 to 4 (2 to 4 if 2 is included) may be provided between adjacent annular units. In this case, the connecting portions are provided so as to be arranged at substantially equal angles with respect to the central axis of the stent. That is, when three connecting portions are provided between adjacent annular units, the arrangement is about 120 degrees.
The material for forming the stent 10 is preferably a material having a certain degree of biocompatibility. For example, stainless steel, tantalum or a tantalum alloy, platinum or a platinum alloy, gold or a gold alloy, or a cobalt base alloy can be considered. 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.

  Furthermore, it is preferable to anneal after producing the final shape of the stent 10. By performing the annealing, the flexibility and plasticity of the entire stent are improved, and the indwellability in the bent blood vessel is improved. Compared to the case without annealing, the force that tries to restore the shape before expansion after expanding the stent, especially the force that tries to return to the linear shape when it expands at the bent blood vessel site, is reduced. The physical stimulation applied to the inner wall of the blood vessel can be reduced, and the factor of restenosis can be reduced. The annealing is preferably performed by heating slowly to 900 to 1200 ° C. in an inert gas atmosphere (for example, argon gas) so that an oxide film is not formed on the stent surface, and then slowly cooling.

  The stent 10 is preferably chamfered. The chamfering method of the stent 10 can be performed by forming the stent into a final shape and then performing chemical polishing, electrolytic polishing or mechanical polishing. The chemical polishing is preferably performed by dipping in a stainless chemical polishing solution. The stainless steel chemical polishing liquid is not particularly limited as long as it can dissolve stainless steel. For example, a mixed liquid composed of hydrochloric acid and nitric acid is used as a basic component, and an organic sulfur compound for adjusting the dissolution rate, smoothing, and imparting gloss. And those to which a surfactant is added are preferred.

Next, the vasodilator of the present invention will be described with reference to the embodiments shown in the drawings.
FIG. 7 is a front view of the living organ dilator according to the embodiment of the present invention. 8 is an enlarged partial cross-sectional view of the distal end portion of the living organ dilator shown in FIG. FIG. 9 is an enlarged cross-sectional view of the rear end portion of the living organ dilator shown in FIG.
In the vasodilator 100 of the present invention, a tubular shaft main body 102, a foldable and expandable balloon 103 provided at the distal end of the shaft main body 102, and a balloon 103 in a folded state are encapsulated. And a stent 101 that is expanded by the expansion of the balloon 103.

The stent 101 is a stent that 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 extends radially from the inside of the tubular body is applied. In this case, a plurality of linear bent portions that expand when a force that spreads in the radial direction is applied, and a portion including the apex of the bent portion is curved inside the stent.
As such a stent 101, the stent 1 or the stent 10 mentioned above can be used, for example.
Further, in the vasodilator 100 of the present invention, the shaft main body portion 102 includes a balloon dilating lumen whose one end communicates with the inside of the balloon 103. The biological organ dilator 100 is fixed to the outer surface of the shaft main body at a position corresponding to both ends of a predetermined length of the X-ray contrast member or the central portion of the stent fixed to the outer surface of the shaft main body at the position to be the central portion of the stent. Two X-ray contrast members.
In the living organ dilator 100 of this embodiment, as shown in FIG. 7, 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.

This biological organ dilating instrument 100 includes a shaft main body 102, a stent expansion balloon 103 fixed to the tip of the shaft main body 102, and a stent 101 on which the balloon 103 is mounted. The shaft body 102 includes an inner tube 112, an outer tube 113, and a branch hub 110.
As shown in FIGS. 8 and 9, 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 2000 mm, more preferably 150 to 1500 mm, and an outer diameter of 0.1 to 1.0 mm, more preferably 0.3 to 0.7 mm, and a thickness of 10 to 10 mm. 150 μm, more preferably 20 to 100 μm. 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 2000 mm, more preferably 150 to 1500 mm, 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. 8, the balloon 103 is foldable, and can be folded on the outer periphery of the inner tube 112 when not expanded. 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 101 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 FIG. 8, the vascular dilator 100 has two X-ray contrast members fixed to the outer surface of the shaft main body at positions corresponding to both ends of the cylindrical portion (expandable portion) when expanded. 117, 118. It should be noted that two X-ray contrast members fixed to the outer surface of the shaft main body 102 (in this embodiment, the inner tube 112) at the positions corresponding to both ends of the predetermined length of the central portion of the stent 101 may be provided. 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.

  As shown in FIG. 9, a linear rigidity imparting body 133 is inserted between the inner tube 112 and the outer tube 113 (inside the balloon expansion lumen 116). The rigidity imparting body 133 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 also provides the rigidity of the living organ expanding device 100. Easy to push the tip. The tip of the rigidity imparting body 133 has a smaller diameter than other parts by a method such as polishing. In addition, it is preferable that the end of the small diameter portion of the rigidity imparting body 133 extends to the vicinity of the end 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, etc. 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. 9, a branch hub 110 is fixed to the proximal end.
The branch hub 110 has a guide wire introduction port 109 that communicates with the guide wire lumen 115 and forms a guide wire port, and communicates with the inner tube hub 122 fixed to the inner tube 112 and the balloon expansion lumen 116. And an outer tube hub 123 fixed to the outer tube 113. The outer tube hub 123 and the inner tube hub 122 are fixed. 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.

  In this embodiment, a bending preventing tube 150 is provided at the end of the outer tube 113. The bending prevention tube 150 is heat-shrinkable, and is formed so that the inner diameter after heat shrinkage is slightly smaller than the outer diameter of the outer tube 113. The tube 150 thus formed is formed as the outer tube 113. Is attached by being contracted by heating (for example, applying hot air). The bending prevention tube 150 is fixed to the outer tube hub 123 by a stop pin 152. In this fixing method, the outer diameter of the portion other than the rear end portion is substantially equal to the inner diameter of the outer tube 113 at the rear end of the outer tube 113, and a stop pin 152 having an enlarged rear end portion is inserted, and the outer tube 113 is inserted into the outer tube 113 Inserting into the outer tube hub 123 from the front end, and pushing the projection 154 provided on the inner surface of the outer tube hub 123 until the rear end portion of the set pin 152 passes. Further, an adhesive may be applied and fixed to the contact surface between the outer tube hub 123 and the bending prevention tube 150.

In addition, a bending prevention tube 160 is provided at the end of the inner tube 112. The tube 160 has heat shrinkability, and is formed so that the inner diameter after heat shrinkage is slightly smaller than the outer diameter of the inner tube 112. The tube 160 having heat shrinkability is connected to the end portion of the inner tube 112. It can be easily attached by shrinking it by heating (for example, applying hot air). The base end portion of the rigidity imparting body 133 is fixed to the outer surface of the inner tube 112 by the contraction tube 160. The inner pipe 112 to which the bending prevention tube 160 is attached is fixed to the inner pipe hub 122. In this fixing method, a stopper pin 162 having a rear end portion having an enlarged diameter is inserted at the rear end of the inner tube 112 at the rear end of the inner tube 112 except for the rear end portion. Inserting into the inner tube hub 122 from the front end and pushing the projection 164 provided on the inner surface of the inner tube hub 122 until the rear end portion of the set pin 162 passes over. Furthermore, an adhesive may be applied and fixed to the contact surface between the inner tube hub 122 and the bending prevention tube 160.
A thermoplastic resin such as polycarbonate, polyamide, polysulfone, polyarylate, methacrylate-butylene-styrene copolymer can be suitably used as the outer tube hub, the inner tube hub, and the material for forming the hub.

The inner tube hub 122 and the outer tube hub 123 are fixed. This fixing is performed by inserting the inner tube 112 from the rear end of the outer tube hub 123 attached to the base end portion of the outer tube 113 and joining the inner tube 112. At this time, by applying an adhesive to the joint between the inner tube hub 122 and the outer tube hub 123, both can be securely fixed.
Note that the structure of the proximal end of the living organ dilator 100 is not limited to the above, and the branch hub 110 is not provided, and the guide wire lumen 115 and the balloon expanding lumen 116 are respectively provided at the rear end, for example. A tube having a port member that forms an opening may be liquid-tightly attached.

Specific examples of the stent of the present invention will be described.
Example 1
A metal pipe obtained by cutting a stainless steel (SUS316L) having a diameter of 2.0 mm and a wall thickness of 0.095 mm into a length of 20 mm was used.
A YAG laser (trade name SL116E) manufactured by NEC was used as the laser processing machine. The metal pipe was set on a jig with a rotary motor with a chuck mechanism so that the shaft would not shake, and this was set on an XY table that could be numerically controlled. The XY table and the rotary motor were connected to a personal computer, and the output of the personal computer was input to the numerical control controller and the rotary motor of the XY table. Drawing software is stored in the personal computer, and a developed drawing of a stent having a composition at the time of molding as shown in FIG. 3 was input thereto.
With such a configuration, based on the drawing data output from the personal computer, the XY table and the rotary motor are driven, and a laser is irradiated to the XY table to produce a stent structure. The laser processing conditions for the metal pipe were as follows: current value 25 A, output 1.5 W, driving speed 10 mm / min.
And the produced stent structure was a chemical polishing liquid for stainless steel (manufactured by Sanshin Chemical Industry Co., Ltd., trade name Sunbit 505, mixed liquid consisting of hydrochloric acid and nitric acid as a basic component, and an organic sulfur compound and a surfactant were added. The product was dipped in a product heated at about 98 ° C. for about 10 minutes and chamfered (deburred and chemically polished) to produce the stent of the present invention.

  The stent formed body thus produced has 12 annular units, two connecting portions facing each other between adjacent annular units, and the axial displacement of the connecting portion of the stent is about 60 degrees. The overall length is 20 mm, the outer diameter is 2.0 mm, the width of the portion constituting the wavy element (the wavy annular body) and the connecting portion is 0.12 mm, the width of the connecting portion is 0.12 mm, and the width of the integrated portion is The thickness was 0.12 mm, the length was 0.1 mm, and the thickness of the entire stent was about 0.08 mm.

  Then, this stent-formed body is fitted on the balloon portion of the PTCA dilatation catheter (balloon catheter), inserted into the mounting device, and the stent is uniformly compressed from the outer surface of the stent toward the center to obtain an outer diameter of 1.0 mm. The biological organ dilating instrument of the present invention having a structure as shown in FIGS. 7 to 9 was produced by reducing the diameter to a balloon shape.

(Comparative Example 1)
A stent of a comparative example was manufactured in the same manner as in Example 1 except that the composition at the time of stent molding input into the personal computer was changed to that shown in FIG.
The stent formed body thus produced has 12 annular units, and has only one connecting portion at a position facing between adjacent annular units, and the axial displacement of the connecting portion of the stent is about 180 degrees. Yes, the overall length is 20 mm, the outer diameter is 2.0 mm, the width of the wavy element (the wavy annular body) and the connecting portion is 0.12 mm, the width of the connecting portion is 0.12 mm, and the width of the integrated portion Was 0.12 mm, the length was 0.1 mm, and the thickness of the entire stent was about 0.08 mm.
Then, this stent-formed body is fitted on the balloon portion of the PTCA dilatation catheter (balloon catheter), inserted into the mounting device, and the stent is uniformly compressed from the outer surface of the stent toward the center to obtain an outer diameter of 1.0 mm. The living body organ dilator was produced by reducing the diameter of the organ to a balloon shape.

(Comparative Example 2)
A stent of a comparative example was manufactured in the same manner as in Example 1 except that the composition at the time of stent molding input into the personal computer was changed to that shown in FIG.
The stent-formed body thus produced has 12 annular units, two connecting portions facing each other between adjacent annular units, the connecting portions are continuous, the total length is 20 mm, and the outer diameter is 2 0.02 mm, the width of the portion constituting the wave element (the wave ring) and the connecting portion is 0.12 mm, the width of the connecting portion is 0.12 mm, the width of the integrated portion is 0.12 mm, and the length is The wall thickness of the entire stent was about 0.08 mm.
Then, this stent-formed body is fitted on the balloon portion of the PTCA dilatation catheter (balloon catheter), inserted into the mounting device, and the stent is uniformly compressed from the outer surface of the stent toward the center to obtain an outer diameter of 1.0 mm. The living body organ dilator was produced by reducing the diameter of the organ to a balloon shape.

(Example 2)
A metal pipe obtained by cutting a stainless steel (SUS316L) having a diameter of 2.0 mm and a wall thickness of 0.095 mm into a length of 50 mm was used.
A YAG laser (trade name SL116E) manufactured by NEC was used as the laser processing machine. The metal pipe was set on a jig with a rotary motor with a chuck mechanism so that the shaft would not shake, and this was set on an XY table that could be numerically controlled. The XY table and the rotary motor were connected to a personal computer, and the output of the personal computer was input to the numerical control controller and the rotary motor of the XY table. Drawing software is stored in the personal computer, and a developed drawing of the stent having the composition at the time of molding shown in FIG. 6 was input thereto.
With such a configuration, based on the drawing data output from the personal computer, the XY table and the rotary motor are driven, and a laser is irradiated to the XY table to produce a stent structure. The laser processing conditions for the metal pipe were as follows: current value 25 A, output 1.5 W, driving speed 10 mm / min.
And the produced stent structure was a chemical polishing liquid for stainless steel (manufactured by Sanshin Chemical Industry Co., Ltd., trade name Sunbit 505, mixed liquid consisting of hydrochloric acid and nitric acid as a basic component, and an organic sulfur compound and a surfactant were added. The product was dipped in a product heated at about 98 ° C. for about 10 minutes, and chamfered (deburring and chemical polishing).

  In this way, a stent-formed body was produced. In the produced stent forming body, the number of annular units is 6, and there are two connecting portions facing each other between adjacent annular units, and the axial displacement of the connecting portion of the stent is about 60 degrees, which constitutes the annular unit. The number of substantially polygonal linear bodies is 6, the shape is substantially rhombus, the length of the major axis is 2.6 mm, the minor axis is 0.9 mm, and the total axial length of the stent is 20 mm. The length of the connecting portion for connecting the elements in the circumferential direction was 0.35 mm, the length of the connecting portion for connecting the annular units was 0.7 mm, and the width was 0.15 mm. The width of the substantially polygonal linear body was 0.2 mm, and the outer diameter of the stent (annular unit) was 2.0 mm.

  Then, this stent-formed body is fitted on the balloon portion of the PTCA dilatation catheter (balloon catheter), inserted into the mounting device, and the stent is uniformly compressed from the outer surface of the stent toward the center to obtain an outer diameter of 1.0 mm. The biological organ dilating instrument of the present invention having a structure as shown in FIGS. 7 to 9 was prepared.

(Experiment)
An X-ray contrast medium is press-fitted at a pressure of 10 kg / cm ² into the balloon lumen of the living organ dilating instrument of Examples 1 and 2 and Comparative Examples 1 and ² , the balloon is expanded, and the stent is expanded to an outer diameter of 3.0 mm. did. Remove the expanded stent from the living organ dilator, fix both ends, measure the load (tensile strength) applied to the stent when pulled 5 mm horizontally with the axial direction, and observe the degree of flexibility in the direction perpendicular to the axial direction. It was.
These results are shown in Table 1.

[Table 1]

┌─────┬────────┬─────────────┐
│ │Tensile strength [kgf] │ Flexibility │
├─────┼────────┼─────────────┤
│ Example 1 │ 0.109 │ ○ │
├─────┼────────┼─────────────┤
│ Example 2 │ 0.090 │ ○ │
├─────┼────────┼─────────────┤
│ Comparative Example 1 │ 0.004 │ ○ │
├─────┼────────┼─────────────┤
│ Comparative Example 2 │ Does not stretch
└─────┴────────┴─────────────┘

FIG. 1 is a front view of an embodiment of the stent of the present invention. FIG. 2 is a partially enlarged view of the stent shown in FIG. FIG. 3 is a development view of the stent shown in FIG. 1. FIG. 4 is a front view of a stent according to another embodiment of the present invention. FIG. 5 is a partially enlarged view of the stent shown in FIG. FIG. 6 is a development view of the stent shown in FIG. 4. FIG. 7 is a front view of the living organ dilator according to the present invention. 8 is an enlarged partial cross-sectional view of the distal end portion of the living organ dilator shown in FIG. FIG. 9 is an enlarged cross-sectional view of the rear end portion of the living organ dilator shown in FIG. FIG. 10 is a development view of the stent of the comparative example. FIG. 11 is a development view of a stent of another comparative example.

Explanation of symbols

1,10 Stent 4 Annular unit

Claims (6)

A stent that is formed into a generally tubular body, has a diameter for insertion into a lumen in a living body, and is expandable when a force extending radially from the inside of the tubular body is applied, A first wavy ring formed in a ring shape by a wavy element, and a ring formed by a wavy element arranged in the axial direction of the stent so that the peak portion is close to the valley of the first wavy ring body A plurality of annular units each including a second corrugated annular body and a plurality of connecting portions connecting the valleys of the first corrugated annular body and the crests of the second corrugated annular body are arranged in the axial direction of the stent. And a connecting portion that connects adjacent annular units at the connecting portion forming portion,
At least one of the plurality of connection portions of the annular unit is an integrated portion in which a valley portion of the first wavy annular body and a peak portion of the second wavy annular body are integrated, The connecting portion is a thin line connecting portion, and the connecting portions are provided between two adjacent annular units and at positions facing each other, and further, only two are connected between the adjacent annular units. One of the parts is for connecting the integrated parts of the adjacent annular units, and the other connecting part is for connecting the thin line-like connection part forming sites of the adjacent annular units. And the said connection part adjacent to the axial direction of the said stent shifts | deviates a predetermined angle with respect to the center axis | shaft of the said stent, and does not continue in the axial direction of a stent, Ste Door. 2. The living body according to claim 1, wherein the connecting portion is inclined at a predetermined angle with respect to a central axis of the stent, and connecting portions adjacent to each other in the axial direction of the stent have different inclination directions. Indwelling stent. The stent for in-vivo indwelling according to claim 1 or 2 arrange | positioned so that it may become two spiral shape which the said 2 connection part interrupts. The connecting portion adjacent to each other in the axial direction of the stent, with shifted about 60 degrees with respect to the central axis of the stent, the connecting portion according to claim 1 or 2 are arranged such that the spiral intermittently In vivo indwelling stent. The indwelling stent according to any one of claims 1 to 4 , wherein a wave-shaped end portion of an adjacent annular unit enters a space formed between adjacent wave-like elements of the annular unit. A tubular shaft main body, a foldable and expandable balloon provided at the distal end of the shaft main body, and a balloon mounted so as to enclose the balloon in a folded state and expanded by expansion of the balloon A living organ dilating device comprising a stent to be operated, wherein the stent is the stent according to any one of claims 1 to 5 .

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