Stent and inspection method thereof

Abstract

The present invention provides a stent and an inspection method thereof that can more reliably ensure the bonding strength of an opaque member to a support unit and the high anti-dropping property of the opaque member in a tubular cavity structure. The stent (11) of the present invention comprises: a leg (17a); and an opaque member (31) having high opacity to radiation, and arranged along the length direction of the protrusion (40, 41) in a manner of covering the protrusion (40, 41) provided on the leg (17a). The opaque member (31) has a sparse range (311) in which the ratio of gaps is larger than a specified sparse density, and a dense range (312) in which the ratio of gaps is smaller than a specified sparse density, and is fixed to the protrusion (40, 41) in the sparse range (311) using an adhesive (42).

Description

Technical Field

[0001] The present invention relates to a stent which is placed in a luminal structure of a living body for expanding the luminal structure or is retrieved from the luminal structure and a method for inspecting the stent. Background Art

[0002] In biological organs with lumen structures such as blood vessels, trachea, and intestines, when stenosis occurs in these organs, a mesh cylindrical stent is used to ensure patency of the lesion by expanding the lumen of the stenotic part. The stent is expanded (deployed) in the lumen structure, thereby expanding the lumen structure.

[0003] Furthermore, when a stent is disposed in a lumen structure, an opaque member (so-called a marker) having high opacity to radiation such as X-rays is provided on a support unit (strut) of the stent in order to confirm the position of the stent in the lumen structure (for example, see Patent Document 1 below). According to such a stent, the opaque member provided in the stent can be seen by irradiating radiation, and the convenience of stent surgery can be improved.

[0004] Prior art literature

[0005] Patent Literature

[0006] Patent document 1: U.S. Publication No. US2018 / 0344337.

[0007] Problem that the invention aims to solve

[0008] In such a stent, the radiopaque member in the lumen structure needs to have high resistance to falling off, but in terms of manufacturing, it is desired to more reliably ensure the bonding strength of the radiopaque member to the struts. Summary of the invention

[0009] An object of the present invention is to provide a stent capable of more reliably ensuring the bonding strength of an opaque member to a strut unit and preventing the opaque member from falling off in a lumen structure.

[0010] Solutions for solving problems

[0011] The present invention relates to a bracket, comprising: a support unit; and an opaque component, which has high opacity to radiation and is arranged along the length direction of the support unit itself or the protrusion arranged on the support unit in a manner of covering the support unit itself or the protrusion arranged on the support unit. The opaque component has a sparse range in which the ratio of gaps is larger than a specified sparse density, and a dense range in which the ratio of gaps is smaller than the specified sparse density, and is fixed to the support unit itself or the protrusion using an adhesive in the sparse range.

[0012] The sparse area may be located closer to the dense area in the opaque member.

[0013] The protrusions may be arranged in pairs with their tips facing each other, and in the opaque member, the portions covering both end sides of the paired protrusions in the longitudinal direction are arranged in the sparse range, and the dense range is arranged between the portions on the both end sides.

[0014] The present invention relates to a method for inspecting a bracket, and the method for inspecting the bracket comprises: confirming the adhesive through the gap in the sparse range.

[0015] Effects of the Invention

[0016] According to the present invention, it is possible to provide a stent and an inspection method thereof that can more reliably ensure the bonding strength of the radiopaque member to the strut unit and the high anti-dropout property of the radiopaque member in the lumen structure. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a perspective view of the basic form of the bracket in the unloaded state.

[0018] Figure 2 This is a development diagram showing a basic form of the stent in an unloaded state, which is virtually developed into a flat surface and a repeated pattern.

[0019] Figure 3 yes Figure 2 A partial enlarged view of the bracket shown.

[0020] Figure 4 yes Figure 3 A partial enlarged view of the bracket shown.

[0021] Figure 5 This is an explanatory diagram showing deformation occurring at the top of the corrugated element of the annular body of the stent when the stent is reduced in diameter.

[0022] Fig. 6A It is a schematic diagram showing the deformation state of the corrugated element when the diameter of the corrugated element of the annular body of the stent is reduced without providing a slit at the top thereof.

[0023] Figure 6B It is a schematic diagram showing the deformation state of the corrugated element when the diameter of the corrugated element of the annular body of the stent is reduced without providing a slit at the top thereof.

[0024] Fig. 7A This is a schematic diagram showing the deformation state of the corrugated element when the diameter of the corrugated element of the annular body of the stent is reduced when a slit is provided at the top of the corrugated element.

[0025] Figure 7B This is a schematic diagram showing the deformation state of the corrugated element when the diameter of the corrugated element of the annular body of the stent is reduced when a slit is provided at the top of the corrugated element.

[0026] Figure 8 It is a partially enlarged view showing a first form of the top of the wave-shaped element of the annular body of the stent.

[0027] Fig. 9 It is a partial enlarged view showing a second form of the top of the wave-shaped element of the annular body of the stent.

[0028] Fig.10 yes Figure 1 An actual expanded view of the basic form of the bracket is shown.

[0029] Fig.11 It is a diagram showing a first arrangement pattern of opaque members.

[0030] Fig.12 It is a diagram showing a second arrangement pattern of the opaque members.

[0031] Fig.13 It is a diagram showing a third arrangement pattern of the opaque members.

[0032] Fig.14 It is a diagram showing a fourth arrangement pattern of the opaque members.

[0033] Fig.15 It is a diagram showing a fifth arrangement pattern of the opaque members.

[0034] Fig.16 It is a diagram showing a sixth arrangement pattern of the opaque members.

[0035] Fig.17 It is a diagram showing a first mode of providing an opaque member, that is, a diagram showing a portion where the opaque member is inserted into the first protrusion and the second protrusion.

[0036] Fig.18 It means for Fig.17 A diagram showing a state where the radiopaque member is not inserted.

[0037] Fig.19A The diagrams sequentially show the process of inserting the non-transmissive member into the first protrusion and the second protrusion.

[0038] Fig.19B The diagrams sequentially show the process of inserting the non-transmissive member into the first protrusion and the second protrusion.

[0039] Fig.19C The diagrams sequentially show the process of inserting the non-transmissive member into the first protrusion and the second protrusion.

[0040] Fig. 20 It is a diagram showing a second embodiment of providing an opaque member.

[0041] Fig.21 This is a diagram showing a third aspect in which an opaque member is provided.

[0042] Fig. 22 It is a diagram showing another embodiment of the opaque member.

[0043] Fig.23 It is a diagram showing another embodiment of the opaque member.

[0044] Fig.24 It is a diagram showing another embodiment of the opaque member.

[0045] Fig.25 It is a diagram showing another embodiment of the opaque member. DETAILED DESCRIPTION

[0046] [Basic form]

[0047] Hereinafter, the embodiment of the stent of the present invention will be described with reference to the accompanying drawings. Figures 1 to 9 , the overall structure of the bracket 11 of the first basic structure without the characteristic structure of the present invention is described. The embodiment of the present invention is, for example, an embodiment in which the characteristic structure of the present invention is set in the basic form. Regarding the characteristic structure of the present invention, use Figures 10 to 18 etc. for explanation.

[0048] Figure 1 This is a perspective view of the basic form of the bracket in the unloaded state. Figure 2 This is a development diagram showing a basic form of the stent in an unloaded state, which is virtually developed into a flat surface with a repeating pattern. Figure 3 yes Figure 2 A partial enlarged view of the bracket shown. Figure 4 yes Figure 3 A partial enlarged view of the bracket shown. Figure 5 This is an explanatory diagram showing deformation occurring at the top of the corrugated element of the annular body of the stent when the stent is reduced in diameter. Fig. 6A and Figure 6B It is a schematic diagram showing the deformation state of the corrugated element when the diameter of the corrugated element of the annular body of the stent is reduced without providing a slit at the top thereof. Fig. 7A and Figure 7B This is a schematic diagram showing the deformation state of the corrugated element when the diameter of the corrugated element of the annular body of the stent is reduced when a slit is provided at the top of the corrugated element. Figure 8 It is a partially enlarged view showing a first form of the top of the wave-shaped element of the annular body of the stent. Fig. 9It is a partial enlarged view showing a second form of the top of the wave-shaped element of the annular body of the stent.

[0049] like Figure 1 As shown, the stent 11 is substantially cylindrical in shape. The peripheral wall of the stent 11 has a mesh pattern structure in which a plurality of closed cells with the same shape are formed by filamentary materials in the circumferential direction. Figure 2 In order to facilitate understanding of the structure of the support 11, the support 11 is shown in a state of being unfolded into a plane. Figure 2 In order to show the periodicity of the mesh pattern, the mesh pattern is shown in a form in which the mesh pattern is repeated more than the actual expanded state. In this specification, the peripheral wall of the stent 11 refers to the part that separates the inside and outside of the cylinder of the roughly cylindrical structure of the stent 11. In addition, the unit is also called an opening or a compartment, which refers to the part surrounded by the filamentary material forming the mesh pattern of the stent 11.

[0050] 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 properties such as nickel-titanium alloy.

[0051] The stent 11 comprises: a plurality of annular bodies 13 arranged as a wave-line pattern in the long axis direction (i.e., the center axis direction) LD; and a plurality of coil-shaped elements 15 arranged as connecting elements between adjacent annular bodies 13 in the long axis direction LD. Figure 3 As shown, 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 legs 17a at the top 17b. Specifically, the substantially V-shaped wavy elements 17 are connected in a state where the tops 17b are alternately arranged on opposite sides.

[0052] When viewed in the radial direction RD perpendicular to the axial direction LD, the annular direction CD of the annular body 13 is inclined relative to the radial direction RD. The angle θ at which the annular direction CD of the annular body 13 is inclined relative to the radial direction RD is, for example, 30 to 60 degrees.

[0053] The two ends of each coil-shaped element 15 are connected with the top 17b of the opposite side of two adjacent annular bodies 13 respectively. In addition, the tops 17b of the opposite side of the adjacent annular bodies 13 are all connected to each other through the coil-shaped element 15. The support 11 has a so-called closed unit structure. That is, two tops 17b located in adjacent positions along the wavy line pattern among the three tops 17b connected to each other by the legs 17a along the wavy line pattern in one side of the adjacent annular bodies 13 are connected to two tops located in adjacent positions along the wavy line pattern among the three tops 17b connected to each other by the legs 17a along the wavy line pattern in the other side of the adjacent annular bodies 13 through the coil-shaped element 15, thereby forming a unit. Moreover, all the tops 17b of the wavy line pattern of each annular body 13 are all shared by three units.

[0054] The plurality of coil-shaped elements 15 are arranged at equal intervals along the axial direction LD. Each coil-shaped element 15 extends in a spiral shape around the central axis. Figure 3 As shown, the winding direction (right winding) of the one coil-shaped element 15 (15R) located on one side of the axial direction LD relative to the annular body 13 is opposite to the winding direction (left winding) of the other coil-shaped element 15 (15L) located on the other side of the axial direction LD. The length of the one coil-shaped element 15R is longer than the length of the leg 17a and is less than 1.5 times the length of the leg 17a. The length of the other coil-shaped element 15L is shorter than the length of the leg 17a.

[0055] In addition, in the present invention, the annular direction CD of the annular body 13 may not be inclined relative to the radial direction RD (the annular direction CD and the radial direction RD may also be parallel). A portion of the top 17b may not be connected by the coil-shaped element 15 (connecting element). The connecting element may not extend in a spiral shape around the axis LD, but may be linear or substantially linear.

[0056] A bent portion 15a is formed at both ends of each coil-shaped element 15. Both ends of each coil-shaped element 15 are connected to the tops 17b (specifically, the tumor-like portions 19) of the two adjacent annular bodies 13 on the opposite sides via the bent portions 15a. Figure 4 As shown, the bent portions 15a at both ends of the coiled element 15 have arc shapes. The tangent direction of the coiled element 15 at the connection end of the coiled element 15 and the top 17b of the wavy line pattern of the ring body 13 coincides with the long axis direction LD.

[0057] The center in the width direction of the end of the coil-shaped element 15 is offset (not coincident) from the apex (center in the width direction) of the top 17b of the annular body 13. One end edge in the width direction of the end of the coil-shaped element 15 coincides with the end edge in the width direction of the top 17b of the annular body 13.

[0058] The stent 11 has the above-described structure, thereby achieving excellent shape compliance and diameter reduction, and is not prone to damage to the stent due to metal fatigue. The tumor-shaped portion 19 provided at the top 17b of the wavy element 17 of the annular body 13 of the stent 11 achieves the effect of reducing metal fatigue. The slit 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 achieves the effect of improving the diameter reduction of the stent 11.

[0059] The closed cell structure of the stent in the prior art lacks structural flexibility, so there is a risk of buckling in a curved blood vessel and obstructing blood flow. In addition, if the stent is locally deformed, the influence of the deformation is not only propagated in the radial direction RD of the stent, but also in the long axis direction LD, so that the stent cannot be deformed locally and independently. Therefore, the stent cannot conform to the complex blood vessel structure such as an aneurysm, and a gap will be generated between the peripheral wall of the stent and the blood vessel wall. The stent will easily slide in the lumen of the blood vessel due to deformation accompanied by the pulsation of the blood vessel, and there is a possibility of migration of the stent after implantation.

[0060] In contrast, when the stent 11 of the basic form is deformed from the expanded state to the reduced diameter state (curled state), the wavy line pattern of the annular body 13 becomes compressed as if folded, and the coil-shaped element 15 becomes stretched in the long-axis direction LD like a spiral spring while lying in the long-axis direction LD. When one of the wavy line 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. Figure 5 As shown, the corrugated element 17 deforms like the opening and closing of tweezers when the stent 11 is contracted and expanded.

[0061] like Fig. 6A As shown in FIG. 1 , in the case where the valley side portion of the root of the corrugated element 17 (the inner peripheral portion of the top 17b) is not provided with the slit 21, if the corrugated element 17 is deformed in a closed manner when the diameter of the stent 11 is reduced, as shown in FIG. Figure 6B As shown, the central portion of the leg 17a is easily deformed and expanded outward into a barrel shape. If the corrugated element 17 is deformed and expanded into a barrel shape in this way, when the bracket 11 is reduced in diameter, the barrel-shaped portions of the leg 17a of the corrugated element 17 adjacent in the circumferential direction in the annular body 13 will contact each other.

[0062] This contact hinders the diameter reduction of the stent 11 (especially the annular body 13 thereof) and becomes the main reason for the low diameter reduction rate. Fig. 7A As shown in FIG. 1 , a slit 21 is provided at the root portion of the wave-shaped element 17 of the annular body 13. Therefore, when the diameter of the stent 11 is reduced, as shown in FIG. Figure 7BAs shown, the bracket 11 is deformed, and the leg portions 17a of the wavy elements 17 adjacent to each other in the circumferential direction in the annular body 13 become less likely to contact each other, thereby increasing the diameter reduction ratio.

[0063] As described above, when the stent 11 is shrunk and expanded, the wave-shaped element 17 Figure 5 As shown in the figure, the stent 11 is deformed like a pair of tweezers opening and closing. Therefore, when the stent 11 is curled and expanded, the deformation is concentrated at the top, and the strain caused by the material deformation occurs concentratedly in this part. Therefore, when the stent 11 is repeatedly reduced in diameter and expanded, or when the stent 11 is repeatedly loaded with deformation caused by the blood flow in the blood vessel and the pulsation of the blood vessel wall, excessive metal fatigue is likely to occur at the top 17b of the wavy element 17. Therefore, in order to reduce the risk of metal fatigue, the shape of the top 17b of the stent 11 is improved to reduce the strain occurring at the top 17b.

[0064] When the stent 11 is shrunk and expanded, the corrugated element 17 opens and closes with the valley side portion (inner peripheral portion) of the root as the center, so the strain of the top 17b of the corrugated element 17 is mostly generated in the area of ​​the top 17b, especially in the outer peripheral portion (in the Figure 5 Here, when the length before deformation is denoted as l0 (Lzero) and the deformation amount is denoted as u, the strain e is expressed by the following formula.

[0065] e=u / l0

[0066] Therefore, in order to reduce the risk of metal fatigue at the top 17 b of the stent 11 , it is only necessary to reduce the strain at the top 17 b generated when the stent 11 is shrunk and expanded.

[0067] If the same deformation amount u is generated when the diameter is reduced, the strain generated at the top 17b can be reduced by increasing the length equivalent to l0. In addition, the deformation of the corrugated element 17 is carried out with the valley side portion (inner peripheral portion) of the root of the corrugated element 17 as the center, and the peak side portion (at the top 17b of the corrugated element 17) substantially contributes to the deformation. Figure 8-Figure 9 The range indicated by the arrows on both sides in the upper part of the Figures 8 to 9 As shown, in the stent 11 , a tumor-like portion 19 is formed at the top 17 b so that the top 17 b is extended in the long axis direction LD. The tumor-like portion 19 includes an extended portion 19 a and a substantially semicircular portion 19 b and has a width greater than that of the coil-shaped element 15 .

[0068] Specifically, an extension portion 19a extending in the long axis direction LD is provided between the leg portion 17a of the corrugated element 17 and the approximately semicircular portion 19b forming the top portion 17b thereof, so that the top portion 17b is offset outward from the valley side portion (inner peripheral portion) of the root portion of the corrugated element 17, which is the deformation base point. Thus, the outer peripheral portion of the top portion 17b is lengthened. In order to prevent the adjacent protuberances 19 in the circumferential direction from contacting each other during the diameter reduction and becoming the main cause of hindering the diameter reduction, as shown in FIG. Figures 8 to 9 As shown, the extended portion 19a is preferably formed by a straight line portion extending in the major axis direction LD.

[0069] In addition, when the top 17b of the corrugated element 17 is formed with a slit 21 extending from the inner peripheral edge of the top 17b, as shown in FIG. Fig. 7A and Figure 7B As shown, the deformation of the wave-shaped element 17 is characterized by the top of the slit 21 ( Figures 8 to 9 The main part involved in the deformation accompanying curling and expansion becomes the part located outside the top of the slit 21 in the wavy element 17. Figure 8 As shown in FIG. 1 , the length of the extension portion 19a is the same as or shorter than the length of the slit 21, preferably as shown in FIG. Fig. 9 As shown, the length of the extension portion 19 a is longer than the length of the slit 21 and the extension portion 19 a extends beyond the top end of the slit 21 .

[0070] like Figure 8 and Fig. 9 As shown, the facing side edges of the slit 21 are straight lines extending substantially parallel to each other. In addition, the facing side edges of the slit 21 may not extend substantially parallel to each other (for example, they may be slightly opened toward the leg portion 17a. Not shown). In addition, the facing side edges of the slit 21 may not be straight lines (not shown).

[0071] Furthermore, when the stent 11 is formed of a superelastic alloy such as nickel-titanium alloy, Fig. 9 As shown, a configuration can be made such that a tumor-like portion 19 is provided at the top 17b of the corrugated element 17 of the annular body 13 of the stent 11, and the length of the extended portion 19a of the tumor-like portion 19 exceeds the length of the slit 21. Thus, the superelastic property of the superelastic alloy can be maximized, and the change in the expansion force with respect to the change in the outer diameter of the stent 11 can be suppressed.

[0072] When the slit 21 is provided at the top 17b of the corrugated element 17 of the annular body 13 of the stent 11, the length of the extended portion 19a of the protuberance 19 provided at the top 17b exceeds the length of the slit 21, so that the volume ratio of the phase transformation to the martensite phase at the periphery of the slit 21 under load is increased. Fig. 9 The wave-shaped element 17 having the top 17 b shown in the figure can slowly change the expansion force with respect to the change in the diameter of the stent 11 , and can realize the stent 11 with little change in the expansion force even under different blood vessel diameters.

[0073] The bent portions 15 a provided at both ends of the coil-shaped element 15 of the stent 11 allow the coil-shaped element 15 to deform more smoothly at the connection portion with the annular body 13 , thereby achieving an effect of improving the diameter reduction property of the stent 11 .

[0074] When the stent 11 is reduced in diameter, the coil-shaped element 15 is deformed in a manner of being stretched in the long-axis direction LD. Therefore, in order to improve the flexibility of the stent 11, it is necessary to design the connection portion between the top 17b of the annular body 13 and the coil-shaped element 15 to be soft. In the stent 11, a curved portion 15a having an arc shape is provided at both ends of the coil-shaped element 15, and the top 17b of the annular body 13 and the coil-shaped element 15 are connected via the curved portion 15a. When the stent 11 is reduced in diameter, the curved portion 15a is bent and deformed, thereby enabling the coil-shaped element 15 to be deformed flexibly, thereby improving the shrinkability.

[0075] In addition, the tangent direction of the bend 15a at the connection end where the coil-shaped element 15 and the top 17b of the annular body 13 are connected is consistent with the long-axis direction LD. This structure achieves the following effects: it makes the deformation caused by the shrinkage and expansion of the stent 11 easier, and slows down the change of the expansion force relative to the change in the diameter of the stent 11.

[0076] The coil-shaped element 15 is stretched in the long-axis direction LD by deforming like a spiral spring, so that it can be deformed in the radial direction RD caused by the shrinkage of the stent 11. Therefore, by making the tangent direction of the bend 15a at the connection end where the annular body 13 and the coil-shaped element 15 are connected consistent with the long-axis direction LD, the deformation characteristics of the coil-shaped element 15 in the long-axis direction LD can be effectively exerted. As a result of the coil-shaped element 15 being able to deform smoothly in the long-axis direction LD, the shrinkage and expansion of the stent 11 become easy. In addition, by promoting the natural deformation of the coil-shaped element 15 in the long-axis direction LD, it is possible to prevent the occurrence of unexpected deformation resistance, and obtain the effect of slowing down the response of the expansion force relative to the change in the diameter of the stent 11.

[0077] The stent 11 is inserted into the catheter in a reduced diameter state, and is pushed by an extruder such as a pusher to move in the catheter and deploy at the lesion site. At this time, the force in the long axis direction LD given by the extruder generates interaction between the annular body 13 and the coil-shaped element 15 of the stent 11 and is transmitted to the entire stent 11.

[0078] Next, the method of using the stent 11 is described. A catheter is inserted into the patient's blood vessel, and the catheter is allowed to reach the lesion site. Next, the stent 11 is reduced in diameter (curled) and arranged in the catheter. The stent 11 has improved diameter reduction properties through the combined effect and synergistic effect of the wavy line pattern of the annular body 13, the slit 21 formed at the top 17b of the annular body 13, the curved portion 15a of the coil-shaped element 15, and the structure in which the tangent direction of the curved portion 15a at the connection end is consistent with the long-axis direction LD. Therefore, compared with the stent of the prior art, the stent 11 can be easily inserted into a thinner catheter, and the stent 11 can be applied to thinner blood vessels.

[0079] Next, an extruder such as a pusher is used to push the stent 11 in a reduced diameter state along the inner cavity of the catheter, and the stent 11 is pushed out from the top of the catheter at the lesion site and expanded (deployed). The stent 11 has improved flexibility during transportation through the combined effect and synergistic effect of the structure in which a plurality of annular bodies 13 are connected by a coil-shaped element 15, the curved portion 15a of the coil-shaped element 15, and the structure in which the tangent direction of the curved portion 15a at the connection end is consistent 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 transported to the lesion site.

[0080] Furthermore, by providing a tumor-like portion 19 at the top 17b of the annular body 13, the stent 11 can suppress the occurrence of metal fatigue and suppress the damage of the stent 11 caused by the following factors, including: repeated shrinkage and expansion of the stent 11 due to implantation errors, repeated deformation of the stent 11 due to blood flow or pulsation of the blood vessel wall, etc.

[0081] In addition, by providing the slit 21 at the top 17b of the annular body 13 to increase the area in the deformed portion that is transformed into the martensite phase when curled, and by the combined effect and synergistic effect of the structure in which the tangent direction of the bent portion 15a of the coil-shaped element 15 and the bent portion 15a at the connection end are consistent with the long-axis direction LD, the stent 11 has improved flexibility, and the change in the expansion force relative to the change in the diameter of the stent 11 during the load removal process becomes smooth. As a result, while improving the shape compliance of the stent 11, even in a portion where the diameter of the blood vessel changes locally, such as a tapered blood vessel, the stent 11 can be placed without applying an excessive load to the blood vessel.

[0082] In addition, the structure of the basic form of the stent 11 is not limited to the above-mentioned structure. For example, the length of the coil-shaped element 15R on one side and the length of the coil-shaped element 15L on the other side may be the same. The length of the coil-shaped element 15R on one side and the length of the coil-shaped element 15L on the other side may both be longer than the length of the leg 17a, or may be shorter than the length of the leg 17a. The spiral direction of the coil-shaped element 15 may be left winding or right winding.

[0083] In the basic form, the wavy line pattern body 13 forms an annular body. On the other hand, in the present invention, a wavy line pattern body 13 that is discontinuous in the circumferential direction and does not form an annular body can be used. The wavy line pattern body 13 that does not form an annular body has the following shape: compared with the wavy line pattern body that forms an annular body, one or more supporting units (legs 17a) constituting the wavy line pattern body are removed. The number of the removed supporting units can be set to one or more as appropriate within the range that can realize the shape of the bracket 11.

[0084] [Arrangement Pattern of Non-Transmissive Members]

[0085] Next, use Figures 10 to 16 , the variation of the arrangement pattern of the non-transmissive components is described. Fig.10 yes Figure 1 An actual expanded view of the basic form of the bracket is shown. Fig.11 It is a diagram showing a first arrangement pattern of opaque members. Fig.12 It is a diagram showing a second arrangement pattern of the opaque members. Fig.13 It is a diagram showing a third arrangement pattern of the opaque members. Fig.14 It is a diagram showing a fourth arrangement pattern of the opaque members. Fig.15 It is a diagram showing a fifth arrangement pattern of the opaque members. Fig.16 It is a diagram showing a sixth arrangement pattern of the opaque members.

[0086] In the present invention, a plurality of substantially cylindrical radiopaque members 31 having high radiopaqueness are arranged near the support unit constituting the annular pattern body (annular body 13) and / or the connecting element (coil-shaped element 15). The manner of arranging the radiopaque members 31 will be described in detail later.

[0087] The plurality of radiopaque members 13 may have regularity and be arranged in one or more of the annular direction CD, the axial direction LD, and the circumferential direction of the stent.

[0088] The opaque member 31 is a member that is highly opaque to radiation and therefore highly visible when irradiating radiation. The material of the opaque member 31 may be metal or synthetic resin. When the stent 11 is provided with the opaque member 31, for example, the expanded (deployed) state of the stent 11 or the curved shape of the stent as a whole can be easily seen.

[0089] The strut (coil-shaped element 15, annular body 13) near which the radiopaque member 31 is arranged is preferably a substantially non-bending strut or a substantially non-deformable strut. The substantially non-bending strut or the substantially non-deformable strut includes the other short coil-shaped element 15L.

[0090] Examples of the metal material of the metal-made radiopaque member 31 include gold, tantalum, platinum, tungsten, iridium, platinum tungsten, and alloys thereof, and also radiopaque polymer materials to which radiopaque fillers are added.

[0091] Fig.10 is with Figure 2 Basically the same expansion diagram, but relative to Figure 2 Yes Figure 1 The basic form of the stent shown is hypothetically unfolded into a flat surface and a repeated pattern is shown in the unfolded view, Fig.10 This is an actual expanded view of the basic form of the bracket. Figures 11 to 16 This is an actual development view of the stent according to the embodiment of the present invention.

[0092] exist Fig.11 In the stent 11-1 having the first arrangement pattern shown, the opaque members 31 are provided at six locations (six) in a Z-shape in the axial direction LD on the leg portions 17a of the annular body 13 arranged along the annular direction CD. The six opaque members 31 are arranged so as not to interfere with each other when the stent 11-1 is reduced in diameter (the same shall apply hereinafter). In addition, in the stent 11-1, second opaque members 32, which are provided in a manner different from that of the opaque members 31, are provided at two distal ends, respectively (the same shall apply hereinafter). The six opaque members 31 form two groups of three. Thus, together with the two second opaque members 32, it is easy to confirm the bending shape of the stent in a bent state, the position of the distal end of the stent, etc. (the same shall apply hereinafter). In addition, the opaque members 31 and 32 are shown as being surrounded by a dotted circle (the same shall apply hereinafter).

[0093] exist Fig.12In the stent 11-2 having the second arrangement pattern shown, the opaque members 31 are provided at four locations (four) in a zigzag pattern along the axial direction LD on the legs 17a of the annular body 13 arranged along the annular direction CD. The four opaque members 31 form two groups of two. The two groups are spaced apart in the axial direction LD.

[0094] exist Fig.13 In the stent 11 - 3 having the third arrangement pattern shown, the radiopaque members 31 are provided at two locations (two) in the leg portions 17 a of the annular bodies 13 arranged in the annular direction CD so as to be staggered in the axial direction LD.

[0095] Figure 11 to Figure 13 The overall skeleton of the bracket shown Figure 14 to Figure 16 The overall skeleton of the stents shown is substantially the same, but the balance of dimensions is different. Fig.14 In the stent 11-4 having the fourth arrangement pattern shown, the radiopaque members 31 are provided at eleven locations (eleven pieces) in a zigzag pattern in the axial direction LD on the legs 17a of the annular body 13 arranged in the annular direction CD. The eleven radiopaque members 31 form a set.

[0096] exist Fig.15 In the stent 11-5 having the fifth arrangement pattern shown, the opaque members 31 are provided at six locations (six) in a zigzag pattern in the axial direction LD on the leg portions 17a of the annular body 13 arranged in the annular direction CD. The six opaque members 31 form two groups of three. The two groups are spaced apart in the axial direction LD.

[0097] exist Fig.16 In the stent 11-6 having the sixth arrangement pattern shown, the opaque members 31 are provided at six locations (six) in a zigzag pattern in the axial direction LD on the leg portions 17a of the annular body 13 arranged along the annular direction CD. The six opaque members 31 are formed into three groups of two. The three groups are spaced apart in the axial direction LD.

[0098] Although not shown in the figure, the radiopaque members 31 may be arranged in the circumferential direction of the stent.

[0099] [Method of providing the non-transmissive member]

[0100] Next, use Fig.17 and Fig.18 The manner in which the opaque member 31 is provided will be described. Fig.17 1 is a diagram showing a first mode of providing an opaque member, and is a diagram showing a location where the opaque member is inserted into the first protrusion and the second protrusion. Fig.18 It means for Fig.17The figure shows a state where the opaque member is not inserted.

[0101] like Fig.17 and Fig.18 As shown in FIG. 1 , a pair of first protrusions 40 and second protrusions 41 are provided on the leg portions 17a of the annular body 13 arranged in the annular direction CD. The radiopaque member 31 is fixed to the first protrusions 40 and the second protrusions 41 using an adhesive 42 .

[0102] The leg portions 17 a of the annular body 13 arranged in the circular direction CD constitute a support unit extending in a predetermined direction (the circular direction CD in this embodiment).

[0103] The first protrusion 40 is located on the proximal side of the stent 11 compared to the second protrusion 41 ( Fig.11 The leg portion 17a is provided in a manner such that the leg portion 17a extends away from the leg portion 17a and then extends to the distal side (the left side) of the stent 11 in a predetermined direction (the annular direction CD). Fig.11 The first protrusion 40 is formed integrally with the leg 17a. The portion of the first protrusion 40 extending in the predetermined direction may be longer than the portion of the second protrusion 41 extending in the predetermined direction (L40>L41).

[0104] The second protrusion 41 is provided on the leg 17a so as to be located on the far side of the stent 11 compared with the first protrusion 40. The second protrusion 41 is a substantially L-shaped protrusion that extends in a direction away from the leg 17a and then extends to the near side of the stent 11 in a predetermined direction (circumferential direction CD). The second protrusion 41 is formed integrally with the leg 17a. The first protrusion 40 and the second protrusion 41 are away from the leg 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).

[0105] The tip 401 of the first protrusion 40 is separated from the tip 411 of the second protrusion 41. The interval L43 between the tip 401 of the first protrusion 40 and the tip 411 of the second protrusion 41 is preferably 30 μm to 10 mm.

[0106] For example, when the total length of the stent is 10 to 100 mm, the interval L43 is 30 μm to 300 μm. When the total length of the stent is 50 to 500 mm, the interval L43 is 0.5 mm to 5 mm.

[0107] 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 10 mm, the interval L43 is 0.5 to 5 mm. In addition, the interval L43 may not substantially exist (may be 0).

[0108] The length L40 of the portion of the first protrusion 40 extending in the predetermined direction is preferably 30 μm to 10 mm.

[0109] For example, when the total length of the stent is 10 to 100 mm, the length L40 is 50 to 1000 μm. When the total length of the stent is 50 to 500 mm, the length L40 is 0.5 to 10 mm.

[0110] Furthermore, 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 10 mm, the length L40 is 5 to 10 mm.

[0111] The length L41 of the portion of the second protrusion 41 extending in the predetermined direction is preferably 20 μm to 10 mm.

[0112] For example, when the total length of the stent is 10 to 100 mm, the length L41 is 50 to 1000 μm. When the total length of the stent is 50 to 500 mm, the length L41 is 0.5 to 10 mm.

[0113] 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 10 mm, the length L41 is 5 to 10 mm.

[0114] In the first protrusion 40 and the second protrusion 41 , portions 402 and 412 on the opposite side of the leg portion 17 a at the base end of the portion extending in a predetermined direction have a convex shape.

[0115] The support unit provided with the first protrusion 40 and the second protrusion 41 is closer to the side opposite to the side provided with the first protrusion 40 and the second protrusion 41 than the adjacent support unit. Thus, even if the first protrusion 40 and the second protrusion 41 are provided, the protrusion distance of the first protrusion 40 and the second protrusion 41 can be reduced compared to the reference position along the length direction of the entire bracket.

[0116] The opaque member 31 is roughly cylindrical with high opacity to radiation, and a first protrusion 40 and a second protrusion 41 are inserted at both ends. The so-called roughly cylindrical shape refers to a shape that is considered to be cylindrical as a whole, in addition to a complete cylindrical shape. The roughly cylindrical shape includes the shape of a coil spring (helical) or the shape of a C-shaped cross section. The opaque member 31 is preferably elastic in the axial direction (length direction) of the tube when it is manufactured, and is a coil spring in this embodiment.

[0117] Such an opaque member 31 has a sparse range 311 in which the ratio of gaps is larger than a predetermined density, and a dense range 312 in which the ratio of gaps is smaller than a predetermined density. Specifically, the opaque member 31 is formed from the proximal side ( Fig.17 The sparse area 311, the dense area 312, and the sparse area 311 are sequentially arranged in the order of the left side in the far side, and the first protrusion 40 and the second protrusion 41 are fixed with the adhesive 42 in the sparse area 311. That is, in the non-transmissive member 31, the portions covering the two end sides of the paired first protrusion 40 and the second protrusion 41 in the length direction are the sparse area 311, and the portions between the two end sides are the dense area 312.

[0118] In the opaque member 31 , the ratio of the length of the dense area 312 adjacent to the sparse area 311 is preferably 1:1.5 to 20.0, with the sparse area 311 as a reference (1). The reference sparse area 311 is the sparse area 311 located at the end of the opaque member 31 .

[0119] From the viewpoint of ensuring visibility, the outer diameter of the opaque member 31 is preferably 0.2 mm or more. When inserted into a catheter with an inner diameter of 0.027 inches, the outer diameter of the opaque member 31 needs to be 0.52 mm or less, and when inserted into a catheter with an inner diameter of 0.028 inches, the outer diameter needs to be 0.55 mm or less.

[0120] The adhesive 42 may be a resin adhesive such as a UV curing adhesive, a thermosetting adhesive, a two-component mixed adhesive, or a cyanoacrylate adhesive. The adhesive may be broadly interpreted as including metal adhesives such as solder and wax.

[0121] Figures 19A to 19C The diagrams sequentially show the process of inserting the non-transmissive member into the first protrusion and the second protrusion.

[0122] like Fig.19A As shown in FIG. 4 , one end side of the non-transmissive member 31 composed of a coil spring is inserted into the first protrusion 40. Fig.19BAs shown in FIG. 1 , the opaque member 31 hits the vicinity of the base end of the first protrusion 40 and then contracts. Therefore, the other end of the opaque member 31 becomes located in the gap 43 between the top end 401 of the first protrusion 40 and the top end 411 of the second protrusion 41 or in a state close thereto. Then, as shown in FIG. Fig.19C As shown, the other end of the radiopaque member 31 is inserted into the second protruding portion 41. The other end of the radiopaque member 31 can be easily inserted into the second protruding portion 41 by utilizing the elastic restoring force of the radiopaque member 31.

[0123] in addition, Figures 19A to 19C The insertion process shown is an example, and the insertion process (insertion method) varies depending on the length or stretchability of the non-transmissive member 31, the length of the first protrusion 40 and / or the second protrusion 41, the interval L43 between the top 401 of the first protrusion 40 and the top 411 of the second protrusion 41, etc.

[0124] exist Fig. 20 In the second embodiment shown, the leg 17a of the annular body 13 arranged in the annular direction CD is provided with a protrusion 44, and the radiopaque member 31 is fixed to the protrusion 44 using an adhesive 42. The tip of the protrusion 44 faces the distal side. No protrusion that pairs with the protrusion 44 is provided.

[0125] The radiopaque member 31 is substantially cylindrical and highly radiopaque, and is inserted into the protrusion 44. Such radiopaque member 31 has a sparse range 311 in which the ratio of gaps is larger than a predetermined density, and a dense range 312 in which the ratio of gaps is smaller than a predetermined density. Specifically, the radiopaque member 31 is formed from the proximal side ( Fig. 20 The sparse area 311 and the dense area 312 are sequentially provided in the distal direction (left side in FIG. 1 ), and the sparse area 311 is fixed to the protrusion 44 using the adhesive 42. That is, in the non-transmissive member 31, the sparse area 311 is located on the proximal side of the stent 11 compared with the dense area 312.

[0126] exist Fig.21 In the third embodiment shown, the radiopaque member 31 is fixed to the leg portion 17 a of the annular body 13 arranged in the annular direction CD using an adhesive 42 .

[0127] The opaque member 31 is substantially cylindrical and highly opaque to radiation, and is inserted into the leg portion 17a. Such an opaque member 31 has a sparse range 311 in which the ratio of gaps is greater than a predetermined density, and a dense range 312 in which the ratio of gaps is less than a predetermined density. Specifically, the opaque member 31 is formed from the proximal side ( Fig.21The sparse area 311 and the dense area 312 are sequentially provided in the distal direction (left side in FIG. 1 ), and the sparse area 311 is fixed to the leg 17a using the adhesive 42. That is, in the opaque member 31, the sparse area 311 is located closer to the stent 11 than the dense area 312. The preferred ratio of the length of the sparse area 311 to the length of the dense area 312 adjacent thereto is as described above.

[0128] [Other forms of non-transmissive member]

[0129] Next, use Figure 22 to Figure 25 Another embodiment of the opaque member 31 will be described. Figure 22 to Figure 25 It is a diagram showing another embodiment of the opaque member.

[0130] exist Fig. 22 In another embodiment shown, the non-transmissive member 31 has a configuration in which a plurality of slits 313 as gaps extending in the circumferential direction are provided in a tube (cylindrical body). By making the width, pitch, length, etc. of the slits 313 different, a sparse range 311 and a dense range 312 can be formed. For example, if the pitch and length of the slits 313 are the same, the range where the slits 313 with a wide width gather becomes the sparse range 311, and the range where the slits 313 with a narrow width gather becomes the dense range 312. If the width and length of the slits 313 are the same, the range where the slits 313 gather with a small pitch becomes the sparse range 311, and the range where the slits 313 gather with a large pitch becomes the dense range 312. If the width and pitch of the slits 313 are the same, the range where the slits 313 with a long length gather becomes the sparse range 311, and the range where the slits 313 with a short length gather becomes the dense range 312. These examples can be combined.

[0131] exist Fig.23 In the other embodiment shown, the radiopaque member 31 has a cross-section in an arc shape (C-shape) and is provided with a plurality of slits 313 as gaps extending in the circumferential direction. That is, the shape of the radiopaque member 31 is not limited to a closed cylindrical shape.

[0132] Furthermore, the shape of the opaque member 31 may be a shape that cannot be called a substantially cylindrical shape and has a curved cross section (not shown).

[0133] exist Fig.24In another embodiment shown, the opaque member 31 has a configuration in which a plurality of slits 313 as gaps extending in the axial direction are provided in a tube (cylindrical body). By making the width, pitch, length, etc. of the slits 313 different, a sparse range 311 and a dense range 312 can be formed. For example, if the pitch and length of the slits 313 are the same, the range where the slits 313 with a wide width gather becomes the sparse range 311, and the range where the slits 313 with a narrow width gather becomes the dense range 312. If the width and length of the slits 313 are the same, the range where the slits 313 gather at a small pitch becomes the sparse range 311, and the range where the slits 313 gather at a large pitch becomes the dense range 312. If the width and pitch of the slits 313 are the same, the range where the slits 313 with a long length gather becomes the sparse range 311, and the range where the slits 313 with a short length gather becomes the dense range 312. These examples can be combined.

[0134] exist Fig.25 In the other embodiment shown, the radiopaque member 31 has a shape in which the cross section is an arc shape (C-shape) and a plurality of slits 313 as gaps extending in the axial direction are provided. That is, the shape of the radiopaque member 31 is not limited to a closed cylindrical shape.

[0135] Furthermore, the shape of the opaque member 31 may be a shape that cannot be called a substantially cylindrical shape and has a curved cross section (not shown).

[0136] The embodiment achieves the following effects.

[0137] (1) A basic form of a stent comprises: a support unit; and an opaque member 31 which is highly opaque to radiation and is arranged along the length direction of the support unit itself or the protrusion provided on the support unit in a manner of covering the support unit itself or the protrusion provided on the support unit. The opaque member 31 has a sparse range 311 in which the ratio of gaps is larger than a prescribed sparse density, and a dense range 312 in which the ratio of gaps is smaller than a prescribed sparse density. The opaque member 31 is fixed to the support unit itself or the protrusion in the sparse range 311 using an adhesive 42.

[0138] According to such a stent, the adhesive 42 can be confirmed through the large gap in the sparse range 311, and the bonding between the opaque member 31 and the support unit becomes reliable. In addition, when a UV curing adhesive is used for the adhesive 42, UV can be reliably irradiated to the adhesive 42, and the bonding strength between the opaque member 31 and the support unit can be more reliably ensured. Furthermore, the anti-falling property of the opaque member 31 in the lumen structure is high. In addition, in the dense range 312, since the gap is small, the opaque member 31 can be more reliably seen. In the stent for cerebrovascular use, the opaque member 31 becomes thin and small, so it is particularly beneficial to ensure the bonding strength and high anti-falling property.

[0139] (2) In the stent of (1) above, in the radiopaque member 31 , the sparse area 311 is located closer to the proximal side than the dense area 312 .

[0140] When the stent is inserted into the catheter, it is easy to get caught in the opening of the catheter. However, according to such a stent, since the sparse area 311 with strong adhesive force is arranged on the proximal side, it is possible to suppress the adhesion between the opaque member 31 and the stent from being peeled off. In addition, it is possible to further prevent the opaque member 31 from falling off in the lumen structure.

[0141] (3) In the bracket of (1) above, the protrusions 40 and 41 are arranged in pairs with their top ends 401 and 411 facing each other, and in the opaque member 31, the parts on the two end sides in the longitudinal direction covering the paired protrusions 40 and 41 are arranged in a sparse range 311, and the dense range 312 is arranged between the parts on the two end sides.

[0142] According to such a stent, since the radiopaque member 31 and the stent are bonded to each other at both ends of the radiopaque member 31, it is possible to prevent the radiopaque member 31 and the stent from being peeled off. Furthermore, it is possible to further prevent the radiopaque member 31 from falling off in the lumen structure.

[0143] (4) A method for inspecting the stent of any one of (1) to (3) above, comprising: confirming the adhesive through the gap in the sparse range 311 .

[0144] According to such a stent inspection method, by observing using the wide gap of the sparse range 311 , it is possible to easily recognize that the adhesion between the radiopaque member 31 and the support unit is ensured.

[0145] As mentioned above, although the preferred embodiment of the present invention has been described, the present invention is not limited to the above-mentioned embodiment, and can be implemented in various forms.

[0146] The configuration is not limited to the configuration of two sparse ranges 311 and dense ranges 312, or the configuration of three sparse ranges 311, dense ranges 312, and sparse ranges 311 in sequence. The configuration may be a configuration of four sparse ranges 311, dense ranges 312, sparse ranges 311, and dense ranges 312 in sequence, or a configuration of five sparse ranges 311, dense ranges 312, sparse ranges 311, dense ranges 312, and sparse ranges 311 in sequence.

[0147] Description of Reference Numerals

[0148] 11: Bracket;

[0149] 17a: Leg (strut);

[0150] 31: radiopaque member;

[0151] 311: sparse range;

[0152] 312: dense range;

[0153] 313: Slit (gap);

[0154] 40: first protrusion (protrusion);

[0155] 41: second protrusion (protrusion);

[0156] 42: Adhesive;

[0157] 44: protrusion.

Claims

1. A bracket, comprising: a support unit; and The radiopaque member has high radiopaqueness and is arranged along the length direction of the support unit itself or the protrusion so as to cover the support unit itself or the protrusion provided on the support unit. The non-transmissive member has a sparse range in which the gap ratio is larger than a predetermined density, and a dense range in which the gap ratio is smaller than the predetermined density, and is fixed to the support unit itself or the protrusion using an adhesive in the sparse range. The protrusions are arranged in pairs with their top ends facing each other. In the opaque member, portions covering both end sides in the longitudinal direction of the paired protrusions are arranged in the sparse range, and the dense range is arranged between the portions on the both end sides.

2. The bracket according to claim 1, wherein: In the radiopaque member, the sparse area is located closer to the dense area.

3. A method for inspecting a stent, inspecting the stent according to claim 1 or 2, the method for inspecting the stent comprising: The adhesive is confirmed by the gap in the sparse range.

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