阅读说明：本技术 支架 (Support frame ) 是由 石田宏辉 于 2020-11-11 设计创作，主要内容包括：本发明提供一种管腔结构内的不透射性构件的防脱落性高、并且不透射性构件对支撑单元的安装性也高的支架。本发明的支架(11)具有：支撑单元(17a),其在规定的方向上延伸；第一突出部(40),其设置在支撑单元(17a),该第一突出部为向远离支撑单元(17a)的方向延伸然后向所述规定的方向的远侧延伸的大致L字形状；第二突出部(41),其以与第一突出部(40)相比位于远侧的方式设置在支撑单元(17a),该第二突出部为向远离支撑单元(17a)的方向延伸然后向所述规定的方向的近侧延伸的大致L字形状,第一突出部(40)的顶端(401)与第二突出部(41)的顶端(411)分离；以及不透射性构件(31),其为对放射线的不透射性高的大致筒状,在不透射性构件的两端分别插入有第一突出部(40)及第二突出部(41)。(The invention provides a bracket which has high anti-dropping performance of a nontransmissive member in a tube cavity structure and high installation performance of the nontransmissive member to a supporting unit. The stent (11) of the present invention comprises: a support unit (17a) extending in a predetermined direction; a first protrusion (40) provided on the support unit (17a), the first protrusion having a substantially L-shape extending in a direction away from the support unit (17a) and then extending distally in the predetermined direction; a second protrusion (41) provided on the support unit (17a) so as to be located on the far side of the first protrusion (40), the second protrusion having a substantially L-shape extending in a direction away from the support unit (17a) and then extending on the near side in the predetermined direction, the tip (401) of the first protrusion (40) being separated from the tip (411) of the second protrusion (41); and a non-transmissive member (31) having a substantially cylindrical shape with high non-transmissivity for radiation, wherein a first protruding portion (40) and a second protruding portion (41) are inserted into both ends of the non-transmissive member, respectively.)

1. A stent, having:

a support unit extending in a predetermined direction;

a first protrusion provided on the support unit, the first protrusion having a substantially L-shape extending in a direction away from the support unit and then extending distally in the predetermined direction;

a second protrusion provided on the support unit so as to be located farther from the support unit than the first protrusion, the second protrusion having a substantially L-shape extending in a direction away from the support unit and then extending in a direction closer to the predetermined direction, and a distal end of the first protrusion being spaced apart from a distal end of the second protrusion; and

and a non-transmissive member having a substantially cylindrical shape with high non-transmissivity for radiation, wherein the first protruding portion and the second protruding portion are inserted into both ends of the non-transmissive member, respectively.

2. The stent of claim 1,

the distance between the top end of the first protruding part and the top end of the second protruding part is 30 μm to 10 mm.

3. The stent of claim 1 or 2,

the substantially cylindrical opaque member has stretchability in the axial direction of the tube.

4. The stent of any one of claims 1 to 3,

a portion of the first protruding portion extending in the predetermined direction is longer than a portion of the second protruding portion extending in the predetermined direction.

5. The stent of any one of claims 1 to 4,

the first and second protruding parts have a shape in which one side of the supporting unit at a tip end is formed to be inclined.

6. The stent of any one of claims 1 to 5,

the first and second protruding portions have a shape that is convex at a portion on the opposite side of the support unit at a base end of a portion extending in the predetermined direction.

7. The stent of any one of claims 1 to 6,

the first protruding portion and the second protruding portion are arranged radially inward of the catheter tube than the support means so that a portion extending in the predetermined direction is along a direction in which the catheter tube is inserted, in a process of being inserted into the catheter tube.

Technical Field

The present invention relates to a stent that is placed in or retrieved from a lumen structure of a living body in order to expand the lumen.

Background

In living organs having a lumen structure such as a blood vessel, a trachea, and an intestine, when stenosis occurs in these organs, a flexible stent (stent) having a mesh cylindrical shape is used in order to ensure the patency of a lesion site by expanding the lumen of the stricture. The luminal structure is expanded by the stent being expanded (deployed) within the luminal structure.

When a stent is disposed in a lumen structure, a non-transmissive member (a so-called marker) having high non-transmissivity to radiation such as X-rays is provided in a support unit (strut) of the stent in order to confirm the position of the stent in the lumen structure (see, for example, patent document 1 below). According to such a stent, the radiopaque member provided on the stent can be seen by irradiation with radiation, and the operational convenience of the stent can be improved.

Documents of the prior art

Patent document

Patent document 1: U.S. publication No. US 2018/0344337.

Problems to be solved by the invention

In such a stent, the non-transmissive member in the lumen structure is required to have high anti-detachment properties, but in terms of manufacturing, it is desirable that the non-transmissive member is also highly attachable to the support unit.

Disclosure of Invention

The purpose of the present invention is to provide a bracket having high resistance to separation of a non-transmissive member in a lumen structure and having high mountability of the non-transmissive member to a support unit.

Means for solving the problems

The invention relates to a stent, comprising: a support unit extending in a predetermined direction; a first protrusion provided on the support unit, the first protrusion having a substantially L-shape extending in a direction away from the support unit and then extending distally in the predetermined direction; a second protrusion provided on the support unit so as to be located farther from the support unit than the first protrusion, the second protrusion having a substantially L-shape extending in a direction away from the support unit and then extending in a direction closer to the predetermined direction, and a distal end of the first protrusion being spaced apart from a distal end of the second protrusion; and a non-transmissive member having a substantially cylindrical shape with high non-transmissivity for radiation, wherein the first protruding portion and the second protruding portion are inserted into both ends of the non-transmissive member, respectively.

The distance between the tip of the first projection and the tip of the second projection may be 30 μm to 10 mm.

The substantially cylindrical opaque member may have elasticity in the axial direction of the cylinder.

Further, a portion of the first protruding portion extending in the predetermined direction may be longer than a portion of the second protruding portion extending in the predetermined direction.

Further, the first and second protruding portions may be formed in a shape in which a side of the supporting unit having a tip end is inclined.

In the first projection and the second projection, a portion of a base end of a portion extending in the predetermined direction on a side opposite to the support unit may have a convex shape.

Further, the first projecting portion and the second projecting portion may be arranged radially inward of the catheter in a manner such that a portion extending in the predetermined direction is along a direction in which the catheter is inserted, in a process of inserting the catheter into the catheter, as compared with the support means.

Effects of the invention

According to the present invention, it is possible to provide a holder in which the non-transmissive member in the lumen structure is highly resistant to coming off and the non-transmissive member is highly attachable to the support unit.

Drawings

Fig. 1 is a perspective view of a stent in a basic form in an unloaded state.

Fig. 2 is a development view showing a basic form of a stent in an unloaded state virtually developed as a plane and a repetitive pattern.

Fig. 3 is an enlarged view of a portion of the stent shown in fig. 2.

Fig. 4 is an enlarged view of a portion of the stent shown in fig. 3.

FIG. 5 is an explanatory view showing that deformation is generated at the top of a wavy element of an annular body of a stent at the time of diameter reduction of the stent.

Fig. 6A is a schematic view showing a deformed state of a wavy element when diameter reduction is performed without providing a slit at the top of the wavy element of the annular body of the stent.

Fig. 6B is a schematic view showing a deformed state of the wavy element when the diameter of the wavy element is reduced without providing a slit at the top of the wavy element of the annular body of the stent.

Fig. 7A is a schematic view showing a deformed state of a wavy element when diameter reduction is performed in a case where a slit is provided at a top portion of the wavy element of the annular body of the stent.

Fig. 7B is a schematic view showing a deformed state of the wavy element when the diameter of the wavy element is reduced in a case where a slit is provided at the top of the wavy element of the annular body of the stent.

FIG. 8 is an enlarged fragmentary view showing a first configuration of the apices of the undulating elements of the annular body of the stent.

FIG. 9 is a close-up view of a second configuration of the apices of the undulating elements of the annular body of the stent.

Fig. 10 is a development view of the stent of the basic form shown in fig. 1.

Fig. 11 is a diagram showing a first arrangement pattern of the opaque members.

Fig. 12 is a diagram showing a second arrangement pattern of the opaque members.

Fig. 13 is a diagram showing a third arrangement pattern of the opaque members.

Fig. 14 is a diagram showing a fourth arrangement pattern of the opaque members.

Fig. 15 is a diagram showing a fifth arrangement pattern of the opaque members.

Fig. 16 is a diagram showing a sixth arrangement pattern of the opaque members.

Fig. 17 is a view showing a portion where the opaque member is inserted into the first protruding portion and the second protruding portion.

Fig. 18 is a diagram showing a state in which the opaque member is not inserted in fig. 17.

Fig. 19A is a view sequentially showing a process of inserting the nontransmissive member into the first protruding portion and the second protruding portion.

Fig. 19B is a view sequentially showing a process of inserting the nontransmissive member into the first protruding portion and the second protruding portion.

Fig. 19C is a view sequentially showing a process of inserting the nontransmissive member into the first protruding portion and the second protruding portion.

Fig. 20A is a schematic view showing a process in which a portion of the radiopaque member enters the catheter.

Fig. 20B is a schematic view showing a process in which a portion of the radiopaque member enters the catheter.

Fig. 21 is a view showing a modification of the first projecting portion and the second projecting portion (corresponding to fig. 18).

Detailed Description

[ basic form ]

Hereinafter, embodiments of the stent of the present invention will be described with reference to the drawings. Before the description of the embodiment, the overall structure of the bracket 11 having no first basic structure of the characteristic structure of the present invention will be described with reference to fig. 1 to 9. The embodiment of the present invention is an embodiment in which, for example, the characteristic configuration of the present invention is provided in a basic form. The characteristic configuration of the present invention will be described with reference to fig. 10 to 18.

Fig. 1 is a perspective view of a stent in a basic form in an unloaded state. Fig. 2 is a development view showing a repetitive pattern in which a stent in a basic form in an unloaded state is virtually developed as a plane. Fig. 3 is an enlarged view of a portion of the stent shown in fig. 2. Fig. 4 is an enlarged view of a portion of the stent shown in fig. 3. FIG. 5 is an explanatory view showing that deformation is generated at the top of a wavy element of an annular body of a stent at the time of diameter reduction of the stent. Fig. 6A and 6B are schematic views showing a deformed state of a wavy element when diameter reduction is performed without providing a slit at the top of the wavy element of the annular body of the stent. Fig. 7A and 7B are schematic views showing a deformed state of a wavy element when diameter reduction is performed in a case where a slit is provided at a top portion of the wavy element of the annular body of the stent. FIG. 8 is an enlarged fragmentary view showing a first configuration of the apices of the undulating elements of the annular body of the stent. FIG. 9 is a close-up view of a second configuration of the apices of the undulating elements of the annular body of the stent.

As shown in fig. 1, the holder 11 has a substantially cylindrical shape. The peripheral wall of the stent 11 has a structure in which a mesh pattern of a plurality of closed cells having an congruent shape surrounded by a wire-like material is laid over in the circumferential direction. In fig. 2, the stent 11 is shown in a state of being expanded to be flat for easy understanding of the structure of the stent 11. In fig. 2, the mesh pattern is shown in a form in which more mesh patterns are virtually repeated than in the actual expanded state in order to show the periodicity of the mesh pattern. In the present specification, the peripheral wall of the holder 11 refers to a portion that separates the inside from the outside of the cylinder of the substantially cylindrical structure of the holder 11. Furthermore, the cells, also called openings or compartments, refer to the portions enclosed by the filiform material forming the mesh pattern of the stent 11.

The stent 11 is formed of a biocompatible material such as stainless steel, tantalum, platinum, gold, cobalt, titanium, or an alloy thereof. The stent 11 is particularly preferably formed of a material having superelastic characteristics such as nitinol.

The holder 11 has: a plurality of annular bodies 13 arranged in a wavy linear pattern in the longitudinal axis direction (i.e., the central axis direction) LD; and a plurality of coil elements 15 as connecting elements arranged between the annular bodies 13 adjacent in the longitudinal axis direction LD. As shown in fig. 3, the annular body 13 has a wavy line pattern formed by connecting a plurality of substantially V-shaped wavy elements 17 in the circumferential direction, and the wavy elements 17 connect two leg portions 17a at the top portions 17 b. Specifically, the substantially V-shaped wavy elements 17 are connected with the apex portions 17b alternately arranged on the opposite side.

The ring direction CD of the ring body 13 is inclined with respect to the radial direction RD when viewed in the radial direction RD perpendicular to the axial direction LD. The annular body 13 is inclined in the annular direction CD at an angle θ of, for example, 30 to 60 degrees with respect to the radial direction RD.

Both end portions of each coil element 15 are connected to the top portions 17b on the facing sides of the adjacent two annular bodies 13. In addition, the top portions 17b on the facing sides of the adjacent annular bodies 13 are all connected to each other by the coil-like elements 15. The holder 11 has a so-called closed cell structure. That is, two top portions 17b located at adjacent positions along the wavy line pattern, of the three top portions 17b connected to each other along the wavy line pattern by the leg portions 17a in one of the adjacent annular bodies 13, are connected to two top portions located at adjacent positions along the wavy line pattern, of the three top portions 17b connected to each other along the wavy line pattern by the leg portions 17a in the other one of the adjacent annular bodies 13, respectively, by the coil-shaped element 15, thereby forming a unit. Moreover, all the top portions 17b of the wavy line pattern of each annular body 13 are shared by three cells.

The plurality of coil-shaped elements 15 are arranged at equal intervals along the axial direction LD. Each coil-like element 15 extends helically around the central axis. As shown in fig. 3, the winding direction (right winding) of one coil element 15(15R) located on one side of the annular body 13 in the axial direction LD is opposite to the winding direction (left winding) of the other coil element 15(15L) located on the other side of the axial direction LD. The length of one coil-shaped element 15R is longer than the length of the leg portion 17a, and is 1.5 times or less the length of the leg portion 17 a. The length of the other coil-like element 15L is shorter than the length of the leg portion 17 a.

In the present invention, the ring direction CD of the ring body 13 may not be inclined with respect to the radial direction RD (the ring direction CD may be parallel to the radial direction RD). A part of the top portion 17b may not be connected by the coil-like member 15 (connecting member). The connection element may not extend spirally around the axis LD, and may be linear or substantially linear.

Bent portions 15a are formed at both ends of each coil element 15. Both ends of each coil element 15 are connected to the top portions 17b (more specifically, the nubs 19 thereof) on the opposite sides of the adjacent two annular bodies 13 via bent portions 15 a. As shown in fig. 4, the bent portions 15a at both end portions of the coil-shaped element 15 have a circular arc shape. The tangential direction of the coil-like element 15 at the connection end of the coil-like element 15 and the top 17b of the wavy line-like pattern of the annular body 13 coincides with the long dimension axis direction LD.

The center in the width direction of the end portion of the coil-like element 15 is shifted (does not coincide) with the apex (center in the width direction) of the top portion 17b of the annular body 13. One end edge in the width direction of the end portion of the coil-shaped element 15 coincides with the end edge in the width direction of the top portion 17b of the annular body 13.

The stent 11 has the structure as described above, thereby achieving excellent shape compliance and diameter reduction, and preventing the stent from being damaged by metal fatigue. The nubs 19 provided at the tops 17b of the undulating elements 17 of the annular body 13 of the stent 11 achieve the effect of reducing metal fatigue. The slits 21 extending from the inner peripheral edge of the top 17b of the wavy element 17 of the annular body 13 of the stent 11 achieve the effect of improving the diameter-reducing property of the stent 11.

The stent of the closed cell structure of the prior art lacks flexibility in structure, and therefore there is a risk that buckling occurs in a bent blood vessel to obstruct blood flow. In addition, if the stent is locally deformed, the influence of the deformation propagates not only in the radial direction RD of the stent but also in the long-dimension axial direction LD, so that the stent cannot be locally independently deformed. Therefore, the stent cannot conform to a complicated vascular structure such as an aneurysm, a gap is generated between the peripheral wall of the stent and the vascular wall, the stent is easily slid in the lumen of the blood vessel due to the deformation caused by the pulsation of the blood vessel, and migration of the stent after the stent is inserted may occur.

In contrast, when the stent 11 of the basic form is deformed from the expanded state to the contracted state (the crimped state), the wavy line pattern of the annular body 13 is compressed as it is folded, and the coil-shaped element 15 is stretched in the longitudinal axis direction LD as it is laid in the longitudinal axis direction LD like a coil spring. When one of the wavy elements 17 of the wavy line pattern of the annular body 13 of the stent 11 is taken out for consideration, as shown in fig. 5, the wavy element 17 deforms like opening and closing of forceps at the time of reduction and expansion of the stent 11.

In the case where the slit 21 is not provided in the valley portion of the root of the wavy element 17 (the inner peripheral edge portion of the crest 17B) as shown in fig. 6A, if the wavy element 17 is deformed so as to close when the stent 11 is reduced in diameter, the central portion of the leg portion 17a is easily deformed to expand outward in a barrel shape as shown in fig. 6B. If the wavy elements 17 are deformed to expand into a barrel shape as described above, the expanded barrel-shaped portions of the leg portions 17a of the wavy elements 17 adjacent in the circumferential direction in the annular body 13 come into contact with each other when the stent 11 is reduced in diameter.

This contact hinders the diameter reduction of the stent 11 (particularly, the annular body 13 thereof) and causes a low diameter reduction ratio. In contrast, in the stent 11 of the basic form, as shown in fig. 7A, slits 21 are provided in the root portions of the wavy elements 17 of the annular body 13. Therefore, when the stent 11 is reduced in diameter, as shown in fig. 7B, the stent 11 is deformed, and the leg portions 17a of the corrugated elements 17 adjacent in the circumferential direction in the annular body 13 are less likely to contact each other, whereby the reduction ratio can be increased.

As described above, when the stent 11 is contracted and expanded, the wavy elements 17 are deformed like tweezers open and close as shown in FIG. 5. Therefore, when the stent 11 is crimped and expanded, the deformation concentrates on the tip, and the strain caused by the material deformation occurs in this portion in a concentrated manner. Therefore, when the diameter reduction and expansion of the stent 11 are repeated, or when the stent 11 is repeatedly subjected to a load along with deformation caused by blood flow in the blood vessel or pulsation of the blood vessel wall, excessive metal fatigue is likely to occur at the apex 17b of the wavy element 17. Therefore, in the bracket 11, in order to reduce the risk of occurrence of metal fatigue, the shape of the top portion 17b is modified so as to reduce the strain occurring at the top portion 17 b.

When the stent 11 is contracted and expanded, the wavy element 17 opens and closes around the valley portion (inner peripheral edge) of the root, and therefore, the strain of the crest 17b of the wavy element 17 is often generated in the area of the crest 17b, particularly the outer peripheral edge (the outer side of the crest 17b indicated by the curved line with arrows at both ends in fig. 5). Here, when the length before deformation is l0(Lzero) and the deformation amount is u, the strain e is expressed by the following equation.

e＝u/l0

Therefore, in order to reduce the risk of metal fatigue occurring in the top portion 17b of the stent 11, the strain of the top portion 17b occurring when the stent 11 is reduced in diameter and expanded may be reduced.

If the same amount of deformation u occurs when the diameter is reduced, the strain occurring in the top portion 17b can be reduced by increasing the length corresponding to l 0. The wavy element 17 is deformed around the valley portion (inner peripheral edge portion) of the root of the wavy element 17, and substantially contributes to the deformation of the peak portion (the range indicated by the double-sided arrow in the upper portion of fig. 8 to 9) of the crest 17b of the wavy element 17, particularly the outer peripheral edge portion thereof. Therefore, as shown in fig. 8 to 9, in the stent 11, the top portion 17b is elongated in the long-dimension axis direction LD by forming a nub 19 at the top portion 17b, the nub 19 including an elongated portion 19a and a substantially semicircular portion 19b and having a width larger than that of the coil-like element 15.

Specifically, an extension 19a extending in the longitudinal axis direction LD is provided between the leg 17a of the corrugated member 17 and a substantially semicircular portion 19b forming the apex 17b thereof, and the apex 17b is offset outward from a valley portion (inner peripheral edge) of the root of the corrugated member 17 serving as a deformation base point. Thereby, the outer peripheral edge portion of the top portion 17b is lengthened. In order to prevent the nub-like portions 19 adjacent in the circumferential direction from contacting each other at the time of diameter reduction and becoming a factor of hindering the diameter reduction, as shown in fig. 8 to 9, the extended portion 19a is preferably formed of a straight portion extending in the longitudinal axis direction LD.

In addition, in the case where the slit 21 extending from the inner peripheral edge portion of the apex portion 17B is formed in the apex portion 17B of the corrugated member 17, the corrugated member 17 is deformed centering on the tip end of the slit 21 (the upper end of the slit 21 in fig. 8 to 9) as shown in fig. 7A and 7B. The main portion participating in the deformation accompanying the curling and the expansion becomes a portion located outside the tip of the slit 21 in the wavy element 17. Therefore, as shown in fig. 9, it is preferable that the length of the extension 19a is longer than the length of the slit 21 and the extension 19a extends beyond the tip of the slit 21, as compared to the case where the length of the extension 19a is the same as the length of the slit 21 or shorter than the length of the slit 21 as shown in fig. 8.

As shown in fig. 8 and 9, the opposing side edges of the slit 21 are linear extending substantially in parallel. The opposing side edges of the slit 21 may not extend substantially in parallel (for example, may be slightly open toward the leg 17a, not shown). The opposing side edges of the slit 21 may not be linear (not shown).

Further, when the stent 11 is formed of a superelastic alloy such as a nickel-titanium alloy, as shown in fig. 9, the top 17b of the wavy element 17 of the annular body 13 of the stent 11 may be provided with the nubs 19, and the length of the extended portions 19a of the nubs 19 may be made to exceed the length of the slits 21. This can maximize the superelastic properties of the superelastic alloy, and suppress the change in expansion force with respect to the change in the outer diameter of the stent 11.

In the case where the slit 21 is provided in the apex 17b of the undulating member 17 of the annular body 13 of the stent 11, the length of the extension 19a of the nub 19 provided in the apex 17b is configured to exceed the length of the slit 21, whereby the volume ratio of the martensite phase transformed in the peripheral portion of the slit 21 under load is increased. Therefore, by configuring the stent 11 to have the wavy element 17 having the crest 17b as shown in fig. 9, the change in the expansion force with respect to the change in the diameter of the stent 11 is gradual, and the stent 11 with less change in the expansion force even in different vessel diameters can be realized.

The bent portions 15a provided at both end portions of the coil element 15 of the stent 11 make the coil element 15 more smoothly deformed at the connection portion with the annular body 13, thereby achieving an effect of improving the diameter-reducing property of the stent 11.

When the diameter of the holder 11 is reduced, the coil element 15 is deformed so as to be stretched in the longitudinal axis direction LD. Therefore, in order to improve the flexibility of the stent 11, it is necessary to design so that the connecting portion between the top 17b of the annular body 13 and the coil-like element 15 becomes flexible. In the stent 11, curved portions 15a having an arc shape are provided at both ends of the coil-like element 15, and the top portion 17b of the annular body 13 and the coil-like element 15 are connected via the curved portions 15 a. When the diameter of the holder 11 is reduced, the bending portion 15a is bent and deformed, whereby the coil element 15 can be flexibly deformed to improve the diameter reduction property.

Further, the tangential direction of the curved portion 15a at the connecting end where the coil-shaped element 15 and the top portion 17b of the annular body 13 are connected coincides with the long dimension axis direction LD, the structure achieves the following effects: deformation due to the reduction and expansion of the stent 11 is facilitated, and the change of the expansion force with respect to the change of the diameter of the stent 11 is slowed.

The coil element 15 is deformed like a coil spring and is extended in the longitudinal axial direction LD, so that the coil element can be deformed in the radial direction RD along with the diameter reduction of the stent 11. Therefore, by making the tangential direction of the curved portion 15a at the connection end of the annular body 13 and the coil element 15 coincide with the long axis direction LD, the deformation characteristics of the coil element 15 in the long axis direction LD can be effectively exhibited. As a result of the coil-shaped element 15 being able to deform smoothly in the longitudinal axis direction LD, the diameter reduction and expansion of the stent 11 become easy. Further, by promoting the natural deformation of the coil-shaped element 15 in the longitudinal axis direction LD, it is possible to prevent the occurrence of unexpected deformation resistance, and obtain an effect that the response of the expansion force with respect to the change in the diameter of the stent 11 becomes slow.

The stent 11 is inserted into the catheter in a reduced diameter state, moved in the catheter by being pushed by an ejector such as a pusher, and expanded at the lesion site. At this time, the force in the longitudinal axis direction LD applied by the extruder is transmitted to the entire stent 11 while causing an interaction between the annular body 13 of the stent 11 and the coil-like element 15.

Next, a method of using the holder 11 will be described. A catheter is inserted into a blood vessel of a patient to reach a lesion. Next, the stent 11 is reduced in diameter (crimped) and disposed in the catheter. The stent 11 has improved diameter-reducing properties by the combined effect and synergistic effect of the wavy line pattern of the annular body 13, the slits 21 formed in the top 17b of the annular body 13, the curved portions 15a of the coil-shaped element 15, and the structure in which the tangential direction of the curved portions 15a at the connection ends coincides with the long-dimension axis direction LD. Therefore, the stent 11 can be easily inserted into a thinner catheter than the stent of the related art, and the stent 11 can be applied to a thinner blood vessel.

Next, the stent 11 in the reduced diameter state is pushed along the lumen of the catheter using an extruder such as a pusher, and the stent 11 is pushed out from the distal end of the catheter at the lesion site and expanded (expanded). The stent 11 has improved flexibility at the time of conveyance by the combined effect and the synergistic effect of the structure in which the plurality of annular bodies 13 are connected by the coil-shaped element 15, the curved portion 15a of the coil-shaped element 15, and the structure in which the tangential direction of the curved portion 15a at the connection end coincides with the long-dimension axis direction LD. Therefore, even when the catheter is inserted into a tortuous blood vessel, the stent 11 can be flexibly deformed along the catheter, and the stent 11 can be easily delivered to the lesion site.

Further, the stent 11 is configured such that the loop-like portion 19 is provided on the top portion 17b of the annular body 13, whereby the occurrence of metal fatigue can be suppressed, and the breakage of the stent 11 due to factors including: repeated diameter reduction and expansion of the stent 11 due to an implantation error, repeated deformation of the stent 11 due to blood flow or pulsation of the blood vessel wall, and the like.

In addition to this, by the combined effect and synergistic effect of the structure in which the slit 21 is provided at the top 17b of the annular body 13 so as to increase the region of phase transformation to the martensite phase in the deformed portion at the time of crimping, and the structure in which the tangential direction of the bent portion 15a of the coil-shaped element 15, the bent portion 15a at the connection end, and the long-dimension axis direction LD coincide, the stent 11 improves flexibility, and the change in expansion force with respect to the change in diameter of the stent 11 during the removal of load becomes smooth. As a result, the shape compliance of the stent 11 is improved, and the stent 11 can be inserted into a site where the diameter of a blood vessel changes locally, such as a tapered blood vessel, without applying an excessive load to the blood vessel.

The structure of the stent 11 in the basic form is not limited to the above structure. For example, the length of one coil-shaped element 15R may be the same as the length of the other coil-shaped element 15L. Both the length of one coil-shaped element 15R and the length of the other coil-shaped element 15L may be longer than the length of the leg portion 17a, or may be shorter than the length of the leg portion 17 a. The helical direction of the coil-like element 15 may be left winding or right winding.

In the basic form, the wavy linear pattern body 13 forms an annular body. On the other hand, in the present invention, the wavy linear pattern body 13 which is discontinuous in the circumferential direction and does not form a ring body can be used. The wavy linear pattern member 13 having no annular body formed therein has the following shape: one or more support units (leg portions 17a) constituting the wavy line pattern body are removed compared to the wavy line pattern body forming the annular body. The number of support units to be removed may be set to one or more as appropriate within a range that can realize the shape of the holder 11.

[ arrangement Pattern of nontransmissive Member ]

Next, a deformation (variation) of the arrangement pattern of the opaque members will be described with reference to fig. 10 to 16. Fig. 10 is a development view of the stent of the basic form shown in fig. 1. Fig. 11 is a diagram showing a first arrangement pattern of the opaque members. Fig. 12 is a diagram showing a second arrangement pattern of the opaque members. Fig. 13 is a diagram showing a third arrangement pattern of the opaque members. Fig. 14 is a diagram showing a fourth arrangement pattern of the opaque members. Fig. 15 is a diagram showing a fifth arrangement pattern of the opaque members. Fig. 16 is a diagram showing a sixth arrangement pattern of the opaque members.

In the present invention, a plurality of substantially cylindrical nontransmissive members 31 having high radiopacity to radiation are arranged in the vicinity of the support units constituting the annular pattern body (annular body 13) and/or the linking elements (coil elements 15). The mode of providing the opaque member 31 will be described in detail later.

The plurality of nontransmissive members 13 have regularity, and may be arranged in one or more of the ring direction CD, the axial direction LD, and the circumferential direction of the stent.

The opaque member 31 is a member having high opacity to radiation, and therefore has high visibility when irradiated with radiation. The material of the opaque member 31 may be metal or synthetic resin. In the case where the stent 11 is provided with the radiopaque member 31, for example, the state in which the stent 11 is expanded (expanded), the curved shape of the entire stent, or the like can be easily seen.

As the supporting means (the coil element 15, the annular body 13) in which the opaque member 31 is arranged in the vicinity thereof, a substantially non-bent supporting means or a substantially non-deformed supporting means is preferable. The other coil element 15L having a short length can be used as the substantially non-bent supporting means or the substantially non-deformed supporting means.

Examples of the metal material of the opaque member 31 made of a metal material include gold, tantalum, platinum, tungsten, iridium, platinum tungsten, and an alloy material thereof. Further, a polymer material having radiopacity to which a radiopaque filler or the like is added may be mentioned.

Fig. 10 is a development view basically similar to fig. 2, but is a development view in which the stent of the basic form shown in fig. 1 is virtually developed into a plane and a repetitive pattern, and fig. 10 is an actual development view of the stent of the basic form, as compared with fig. 2. Fig. 11 to 16 are actual development views of the stent according to the embodiment of the present invention.

In the stent 11-1 having the first arrangement pattern shown in fig. 11, six (six) nontransmissive members 31 are provided in a zigzag manner in the axial direction LD at the leg portions 17a of the annular body 13 arranged in the annular direction CD. The six nontransmissive members 31 are arranged so as not to interfere with each other when the diameter of the holder 11-1 is reduced (the same applies hereinafter). Further, in the stent 11-1, second nontransmissive members 32 disposed in a different manner from the nontransmissive members 31 are disposed at both distal ends, respectively (the same applies hereinafter). The six nontransmissive members 31 form two groups of three. Thereby, the curved shape of the stent in the curved state, the position of the distal end of the stent, and the like (the same applies hereinafter) are easily confirmed together with the two second nontransmissive members 32. The nontransmissive members 31 and 32 are illustrated as being surrounded by a circle of broken lines (the same applies hereinafter).

In the stent 11-2 having the second arrangement pattern shown in fig. 12, the nontransmissive members 31 are provided at four places (four places) in a zigzag shape along the axial direction LD in the leg portions 17a of the annular body 13 arranged in the annular direction CD. The four nontransmissive members 31 form two groups in such a manner that two are one group. The two groups are spaced apart in the axial direction LD.

In the stent 11-3 having the third arrangement pattern shown in fig. 13, the opaque members 31 are provided at two (two) positions shifted in the axial direction LD in the leg portions 17a of the annular body 13 arranged in the annular direction CD.

The overall skeleton of the stent shown in fig. 11 to 13 is substantially the same as that of the stent shown in fig. 14 to 16, but the arrangement is different. In the stent 11-4 having the fourth arrangement pattern shown in fig. 14, the nontransmissive members 31 are provided eleven (eleven) in a zigzag manner in the axial direction LD at the leg portions 17a of the annular bodies 13 arranged in the annular direction CD. Eleven nontransmissive members 31 form one group.

In the stent 11-5 having the fifth arrangement pattern shown in fig. 15, six (six) nontransmissive members 31 are provided in a zigzag manner in the axial direction LD at the leg portions 17a of the annular body 13 arranged in the annular direction CD. The six nontransmissive members 31 form two groups of three. The two groups are spaced apart in the axial direction LD.

In the stent 11-6 having the sixth arrangement pattern shown in fig. 16, six (six) nontransmissive members 31 are provided in a zigzag manner in the axial direction LD at the leg portions 17a of the annular body 13 arranged in the annular direction CD. The six nontransmissive members 31 form three groups in a group of two. The three groups are spaced apart in the axial direction LD.

Although not shown, the nontransmissive members 31 may be arranged in the circumferential direction of the stent.

[ means for providing an opaque member ]

Next, a mode of providing the opaque member 31 will be described with reference to fig. 17 and 18. Fig. 17 is a view showing a portion where the opaque member is inserted into the first protruding portion and the second protruding portion. Fig. 18 is a diagram showing a state in which the opaque member is not inserted in fig. 17.

As shown in fig. 17 and 18, a pair of first and second protruding portions 40 and 41 is provided on the leg portion 17a of the annular body 13 arranged in the annular direction CD. The opaque member 31 is fixed to the first protrusion 40 and the second protrusion 41 with an adhesive 42.

The leg portions 17a of the annular body 13 arranged in the ring direction CD constitute support means extending in a predetermined direction (in the ring direction CD in this embodiment).

The first protruding portion 40 is provided on the leg portion 17a so as to be located closer to the stent 11 (on the left side in fig. 11) than the second protruding portion 41, and is a substantially L-shaped protrusion extending in a direction away from the leg portion 17a and then extending in a predetermined direction (the loop direction CD) toward the far side (the right side in fig. 11) of the stent 11. The first protruding portion 40 is integrally formed with the leg portion 17 a. The portion of the first protruding portion 40 extending in the predetermined direction may be longer than the portion of the second protruding portion 41 extending in the predetermined direction (L40 > L41).

The second protruding portion 41 is provided on the leg portion 17a so as to be located farther from the holder 11 than the first protruding portion 40, and is a substantially L-shaped protrusion extending in a direction away from the leg portion 17a and then extending in a predetermined direction (loop direction CD) toward the holder 11. The second protruding portion 41 is integrally formed with the leg portion 17 a. The first protruding portion 40 and the second protruding portion 41 are distant from the leg portion 17a in the same direction. The portion of the second protrusion 41 extending in the predetermined direction may be shorter than the portion of the first protrusion 40 extending in the predetermined direction (L41 < L40).

The top end 401 of the first projection 40 is separated from the top end 411 of the second projection 41. The interval L43 between the tip 401 of the first projecting portion 40 and the tip 411 of the second projecting portion 41 is preferably 30 μm to 10 mm.

For example, when the total length of the stent is 10 to 100mm, the interval L43 is 30 to 300. mu.m. When the total length of the stent is 50 to 500mm, the interval L43 is 0.5 to 5 mm.

For example, when the total length of the opaque member 31 is 100 to 1000 μm, the interval L43 is 30 to 300 μm. When the total length of the opaque member 31 is 1 to 10mm, the interval L43 is 0.5 to 5 mm. The interval L43 may not be substantially present (may be 0).

The length L40 of the portion of the first projecting portion 40 extending in the predetermined direction is preferably 30 μm to 10 mm.

For example, when the total length of the stent is 10 to 100mm, the length L40 is 50 to 1000 μm. The length L40 is 0.5-10 mm when the total length of the stent is 50-500 mm.

For example, when the total length of the opaque member 31 is 100 to 1000 μm, the length L40 is 30 to 200 μm. When the total length of the opaque member 31 is 1 to 10mm, the length L40 is 5 to 10 mm.

The length L41 of the portion of the second projecting portion 41 extending in the predetermined direction is preferably 20 μm to 10 mm.

For example, when the total length of the stent is 10 to 100mm, the length L41 is 50 to 1000 μm. The length L41 is 0.5-10 mm when the total length of the stent is 50-500 mm.

For example, when the total length of the opaque member 31 is 100 to 1000 μm, the length L41 is 30 to 200 μm. When the total length of the opaque member 31 is 1 to 10mm, the length L41 is 5 to 10 mm.

In the first protruding portion 40 and the second protruding portion 41, portions 402 and 412 on the opposite side of the leg portion 17a at the base end of the portion extending in the predetermined direction have a shape formed in a convex shape.

The support unit provided with the first protruding portion 40 and the second protruding portion 41 is closer to the side opposite to the side provided with the first protruding portion 40 and the second protruding portion 41 than the adjacent support unit. Thus, even if the first protruding portion 40 and the second protruding portion 41 are provided, the protruding distance of the first protruding portion 40 and the second protruding portion 41 can be reduced as compared with the reference position along the longitudinal direction of the entire bracket.

The opaque member 31 has a substantially cylindrical shape with high opacity to radiation, and has a first protruding portion 40 and a second protruding portion 41 inserted into both ends thereof. The substantially cylindrical shape means a shape that is regarded as a cylindrical shape as a whole in a broad sense, in addition to a complete cylindrical shape. The substantially cylindrical shape includes a shape of a coil spring (spiral shape), a shape of a C-shaped cross section, and the like. The opaque member 31 is preferably stretchable in the axial direction (longitudinal direction) of the tube during production, and is a coil spring in the present embodiment. Such a nontransmissive member 31 preferably has a sparse range in which the gap ratio is larger than a predetermined density. This facilitates insertion into the first protruding portion 42 and the second protruding portion 41 due to shrinkage during manufacturing, and the coil spring is not excessively hard.

From the viewpoint of ensuring visibility, the outer diameter of the nontransmissive member 31 is preferably 0.2mm or more. For example, when the catheter is inserted into a catheter having an inner diameter of 0.027inch, the outer diameter of the opaque member 31 needs to be 0.52mm or less, and when the catheter is inserted into a catheter having an inner diameter of 0.028inch, the outer diameter needs to be 0.55mm or less.

As the adhesive 42, a resin adhesive such as a UV curable adhesive, a thermosetting adhesive, a two-liquid mixing adhesive, or a cyanoacrylate adhesive is used as appropriate. As widely explained, the adhesive agent widely includes a metal-based adhesive agent such as solder, wax, or the like.

Fig. 19A to 19C are diagrams sequentially showing a process of inserting the opaque member into the first protruding portion and the second protruding portion.

As shown in fig. 19A, one end side of the nontransmissive member 31 made of a coil spring is inserted into the first protruding portion 40. As shown in fig. 19B, the nontransmissive member 31 collides near the base end of the first protruding portion 40, and then contracts. Therefore, the other end of the nontransmissive member 31 is positioned at or close to the distance 43 between the tip 401 of the first protruding portion 40 and the tip 411 of the second protruding portion 41. Then, as shown in fig. 19C, the other end of the nontransmissive member 31 is inserted into the second protrusion 41. The other end of the opaque member 31 can be easily inserted into the second protruding portion 41 by the elastic restoring force of the opaque member 31.

The insertion process shown in fig. 19A to 19C is an example, and the insertion process (insertion method) differs depending on the length or stretchability of the nontransmissive member 31, the length of the first protruding portion 40 and/or the second protruding portion 41, the distance L43 between the tip 401 of the first protruding portion 40 and the tip 411 of the second protruding portion 41, and the like. Even if the insertion process is different, it can be said that it is easy to insert the nontransmissive member 31 into the first protruding portion 40 and the second protruding portion 41, as compared with the case where the above-described interval L43 is substantially absent.

Fig. 20A and 20B are schematic views showing a process in which a part of the opaque member enters the catheter.

During insertion of the stent into the catheter 50, the first protruding portion 40 and the second protruding portion 41 are arranged radially inward of the catheter 50 with respect to the leg portion 17a so that the portions extending in the predetermined direction are along the insertion direction JD of insertion into the catheter 50. Specifically, as shown in fig. 20A, the following is found: when the first projecting portion 40 and the second projecting portion 41 are located at positions distant from the opening of the guide tube 50, even if the first projecting portion 40 and the second projecting portion 41 are arranged outside the guide tube 50 in the radial direction and/or even if the direction in which the supporting unit provided with the first projecting portion 40 and the second projecting portion 41 extends is inclined with respect to the insertion direction JD, during the insertion process, as shown in fig. 20B, the direction in which the supporting unit provided with the first projecting portion 40 and the second projecting portion 41 extends is substantially parallel with respect to the insertion direction JD, and the first projecting portion 40 and the second projecting portion 41 are arranged inside the guide tube 50 in the radial direction.

Fig. 21 is a view showing a modification of the first projecting portion and the second projecting portion (corresponding to fig. 18). In the modification shown in fig. 21, the first projecting portion 40 and the second projecting portion 41 are provided in pairs with a space L43 (pitch 43) therebetween and with their distal ends facing each other. The first and second protruding portions 40 and 41 are formed in a shape inclined on the leg portion 17a side at the tip end.

[ Effect of embodiment ]

The stent of the embodiment produces the following effects.

As shown in fig. 17 and 18, the stent of the embodiment includes: a support unit extending in a predetermined direction; a first protrusion 40 provided in the support unit, the first protrusion having a substantially L-shape extending in a direction away from the support unit and then extending distally in the predetermined direction; a second protrusion 41 provided on the support unit so as to be located on the far side from the first protrusion 40, the second protrusion having a substantially L-shape extending in a direction away from the support unit and then extending on the near side in the predetermined direction, the tip 401 of the first protrusion 40 being spaced apart from the tip 411 of the second protrusion 41; and a non-transmissive member 31 having a substantially cylindrical shape with high non-transmissivity for radiation, wherein the first protruding portion 40 and the second protruding portion 41 are inserted into both ends of the non-transmissive member 31.

According to such a holder, since the nontransmissive member 31 is supported from both ends, the strength of the holder can be improved in structure, and the end of the nontransmissive member 31 can be prevented from protruding outward. Further, the prevention of the separation of the opaque member 31 from the lumen structure can be improved. The stent is particularly effective in preventing detachment when the stent is inserted through a blood vessel having a large number of curved portions. Since the distal end 401 of the first protruding portion 40 is separated from the distal end 411 of the second protruding portion 41, the nontransmissive member 31 can be attached to the support unit as shown in fig. 19A to 19C, for example, by the pitch 43 between the distal end 401 of the first protruding portion 40 and the distal end 411 of the second protruding portion 41, and therefore the attachability of the nontransmissive member 31 to the support unit is also high. In the stent for a cerebral blood vessel, the nontransmissive member 31 is thin and small, and therefore, high mountability is particularly advantageous.

The substantially cylindrical opaque member 31 has elasticity in the axial direction of the cylinder.

According to such a stent, by contracting the nontransmissive member 31 in the axial direction, the nontransmissive member 31 is inserted from the distance 43 between the distal end 401 of the first protruding portion 40 and the distal end 411 of the second protruding portion 41, and the first protruding portion 40 and the second protruding portion 41 are easily inserted into both ends of the nontransmissive member 31, respectively.

As shown in fig. 18, the portion of the first protruding portion 40 extending in the predetermined direction is longer than the portion of the second protruding portion 41 extending in the predetermined direction.

According to such a stent, the nontransmissive member 31 can be further prevented from coming off when the stent is moved to the proximal side of the catheter. In the case of insertion during the insertion process shown in fig. 19A to 19C, the nontransmissive member 31 is contracted to the maximum extent on the side of the first protruding portion 40 that is longer than the second protruding portion 41, and thereby the other end of the nontransmissive member 31 is easily positioned at or close to the distance 43 between the tip 401 of the first protruding portion 40 and the tip 411 of the second protruding portion 41.

As shown in fig. 21, the first and second protruding portions 40 and 41 have a shape in which one side of the supporting unit at the tip end is formed to be inclined.

According to such a stent, since the nontransmissive member 31 is easily inserted into the first protruding portion 40 and the second protruding portion 41 at the time of manufacturing, the stent can be easily manufactured.

As shown in fig. 18, of the first protruding portion 40 and the second protruding portion 41, portions 402 and 412 on the opposite side of the support unit at the base end of the portion extending in the predetermined direction have a shape formed in a convex shape.

According to such a stent, since a step is less likely to occur between the adhesive 42 and the support unit, the inside of the blood vessel is not easily damaged during use.

As shown in fig. 20A and 20B, the first projecting portion 40 and the second projecting portion 41 are arranged more inward in the radial direction of the catheter 50 than the support means so that the portions extending in the predetermined direction are along the direction of insertion into the catheter 50 in the process of insertion into the catheter 50.

According to such a stent, the nontransmissive members 31 inserted into the first protruding portion 40 and the second protruding portion 41 are less likely to come into contact with the catheter 50 in the process of inserting the stent into the catheter 50. Therefore, the stent has high insertability into the catheter 50.

The preferred embodiments of the present invention have been described above. However, the present invention is not limited to the above embodiment, and can be implemented in various ways.

Description of the reference numerals

11: support (tent)

17 a: leg (strut)

31: non-transmissive member

40: first protruding part

41: second protrusion

50: catheter tube