JP7059182B2 - Thin scaffold - Google Patents

Description

[0001] The present invention relates to a bioabsorbable scaffold, and more particularly to a bioabsorbable scaffold for treating the anatomical lumen of the body.

[0002] Radially expandable body prostheses are artificial devices adapted to be implanted in the anatomical lumen. "Anatomical lumen" refers to the lumen, or tube, of a tubular organ such as a blood vessel, urinary tract, or bile duct. A stent is an example of an in-vivo prosthesis that is substantially cylindrical and that keeps a portion of the anatomical lumen open and in some cases dilates. Stents are often used in the treatment of intravascular atherosclerotic stenosis. "Stenosis" refers to a stenosis or stenosis of the diameter of a passage or opening in the body. In such treatments, stents reinforce the walls of blood vessels and prevent restenosis after angioplasty in the vasculature. "Restenosis" refers to the recurrence of stenosis in a blood vessel or heart valve after being treated (by balloon angioplasty, stenting, or valvuloplasty) and apparently successful.

[0003] Treatment of an affected area or lesion with a stent involves both introduction and deployment of the stent. "Introduction" refers to the introduction and delivery of a stent through the anatomical lumen to a desired treatment site such as a lesion. "Deployment" corresponds to the expansion of the stent within the lumen of the therapeutic area. To introduce and deploy a stent, the stent is positioned around one end of the catheter, the end of the catheter is inserted through the skin into the anatomical lumen, and the catheter is treated as desired within the anatomical lumen. This is achieved by advancing to position, expanding the stent at the treatment position, and removing the catheter from the lumen.

[0004] Scaffolds and stents have traditionally fallen into two general categories: balloon-expandable and self-expandable. The latter type expands (at least partially) within the blood vessel to an expanded or expanded state when the radial constraint is removed, while the former utilizes externally applied forces to itself. From the crimped or stored state to the expanded or expanded state.

[0005] Self-expandable stents are designed to expand significantly when radial constraints are removed and often do not require a balloon to deploy the stent. Self-expandable stents undergo no plastic or inelastic deformation when stored in the sheath (with or without an auxiliary balloon) or expanded in the lumen, or are relatively resistant. Balloon-expandable stents or scaffolds, in contrast, undergo significant plastic or inelastic deformation both when crimped and later deployed by the balloon.

[0006] In the case of a balloon dilated stent, the stent is attached around the balloon portion of the balloon catheter. The stent is compressed or crimped onto the balloon. Crimping can be achieved by the use of iris-type or other forms of crimping, such as the crimping machine disclosed and illustrated in US Patent Application No. 2012/0042501. Significant amounts of plastic or inelastic deformation occur when the balloon-expandable stent or scaffold is crimped and later deployed by the balloon. At the treatment site within the lumen, the stent is inflated by inflating a balloon.

[0007] The stent must be able to meet some basic functional requirements. The stent (or scaffold) must be able to sustain radial compressive forces in supporting the walls of the vessel. Therefore, the stent must have the appropriate radial strength. After deployment, the stent must properly maintain its size and shape throughout its useful life despite the various forces that can be applied to the stent. In particular, the stent must properly maintain the blood vessel to the specified diameter for the desired treatment period despite these forces. The duration of treatment may correspond to the time required for the vessel wall to reshape, after which the stent is no longer needed.

[0008] Examples of bioabsorbable polymer scaffolds include Limon US Pat. No. 8,002,817, Lord US Pat. No. 8,303,644, and Yang US Pat. No. 8, 388,673 includes those described in the specification. FIG. 1 shows the distal region of a bioabsorbable polymer scaffold designed to be introduced through an anatomical lumen using a catheter and plastically expanded using a balloon. The scaffold has a cylindrical shape with a central axis 2 and contains a pattern of interconnected structural elements called bar arms or struts 4. The axis 2 extends through the center of the cylindrical shape formed by the struts 4. The stresses involved during compression and unfolding are widely dispersed throughout the strut 4, but are concentrated at the bending element, apex or strut junction. The struts 4 include a series of ring struts 6 connected to each other at the top 8. The ring struts 6 and the apex 8 form a sinusoidal ring 5. The ring 5 is arranged about the axis 2 in the longitudinal direction. The struts 4 also include link struts 9 that connect the rings 5 to each other. The ring 5 and the link strut 9 collectively form a tubular scaffold 10 having an axis 2, where the axis 2 represents the luminal or longitudinal axis of the scaffold 10. Ring 5d is located at the distal end of the scaffold. The apex 8 forms a smaller angle when the scaffold 10 is crimped into the balloon and a larger angle when it is plastically expanded by the balloon. After unfolding, the scaffold receives a static, periodic compressive load from the surrounding tissue. The ring 5 is configured to maintain a radial extension of the scaffold after deployment.

[0009] The scaffold can be made from a biodegradable, bioabsorbable, bioreabsorptive, or bioerodible polymer. The terms biodegradable, bioabsorbable, bioreabsorbable, biosoluble or bioerodible refer to the properties of a material or stent that is degraded, absorbed, reabsorbed or eroded and disappears from the transplant site. The scaffold may also be constructed of bioerodible metals and alloys. Scaffolds are intended to remain in the body for a limited period of time, as opposed to durable metal stents. In many therapeutic applications, the presence of a stent in the body may be necessary for a limited period of time until its intended function is achieved, for example, maintenance of vascular patency and / or drug delivery. In addition, biodegradable scaffolds have been shown to enable improved healing of the anatomical lumen compared to metal stents, which can lead to a reduced incidence of late thrombosis. .. In these cases, treat the vessel with a polymer scaffold, especially a bioabsorbable or reabsorbable polymer scaffold, rather than a metal stent so that the presence of the prosthesis in the vessel is temporary. It is desired to do.

[0010] In some of the methods below, polymer materials considered for use as polymer scaffolds, such as poly (L-lactide) (“PLLA”), poly (D, L-lactide-co-glycolide). ) (“PLGA”), poly (D-lactide-co-glycolide) or poly (L-lactide-co-D-lactide) (“PLLA-co-PDLA”), poly (“PLLA-co-PDLA”) containing less than 10% D-lactide. Blends of L-lactide-co-caprolactone), poly (caprolactone), PLLD / PDLA stereo complexes, and the polymers described above may be described by comparison with the metal materials used to form the stent. Polymeric materials usually have a lower strength-volume ratio compared to metals, which means that more material is needed to provide comparable mechanical properties. Therefore, the struts must be thicker and wider in order for the stent to have the strength required to support the luminal wall at the desired radius. Scaffolds made from such polymers also tend to be brittle or have limited fracture toughness. The inherent anisotropy and velocity-dependent inelastic properties of the material (ie, the strength / stiffness of the material varies with temperature, hydration, thermal history, as well as the rate at which the material deforms). , Especially when working with bioabsorbable polymers such as PLLA and PLGA, only exacerbate this complexity.

[0011] A further challenge when using bioabsorbable polymers (and polymers generally consisting of carbon, hydrogen, oxygen and nitrogen) in the scaffold structure is that the material is radiopermeable and non-radiopermeable. be. Bioabsorbable polymers tend to have X-ray absorption similar to body tissue. A known method of addressing this problem is to attach radiodensity markers to structural elements of the scaffold, such as struts, bar arms, and links. For example, FIG. 1 shows a link element 9d that connects the distal end ring 5d to the adjacent ring 5. The link element 9d has a pair of holes. Each hole holds a radiodensity marker 11. There is a problem in using the marker 11 in combination with the scaffold 10. A reliable way to attach the marker 11 to the link element 9d during a processing step such as crimping the scaffold into a balloon, or to prevent the marker 11 from separating from the scaffold when the scaffold is balloon expanded from the crimped state. is required. These two events, crimp and balloon dilation, are particularly problematic for marker attachment to the scaffold, as both events induce significant plastic deformation in the scaffold body. If this deformation causes significant out-of-plane or irregular deformation of struts that support or are near the marker, the marker can fall off (eg, the strut holding the marker crimps). If twisted or bent inside, the marker may fall out of the hole). A scaffold having a radiodensity marker and a method for attaching the marker to the scaffold body are discussed in US Patent Application No. 2007/01562330.

[0012] There is a need to improve the certainty of fixing the radiodensity marker to the scaffold for thin-walled scaffolds. In connection with this need, there is a need to improve the performance characteristics of scaffolds, especially thin-walled scaffolds made of bioabsorbable materials that must be sent around meandering anatomy.

[0013] Disclosed is a radiopermeable marker and a serpentine anatomical structure of a catheter that retains such radiodensity material and is fitted with a reduced crimp profile and / or a scaffold. A bioabsorbable scaffold with a scaffold structure that allows for improved adaptability to the catheter when pushed through.

[0014] The scaffolds disclosed herein are suitable for satisfying one or a combination of the following purposes:
(I) To thin the crimp profile of the thin scaffold that supports the radiodensity marker.
(Ii) Fixing the marker to the thin scaffold.
(Iii) To reduce strain energy accumulation in a marker retention structure when a thin scaffold is deformed during crimping, balloon dilation at a target vessel site, or during introduction of a scaffold into a target site.
(Iv) To reduce flaring of the end ring at the distal end of the scaffold for thin-walled scaffolds, or scaffolds containing PLLA and having a wall thickness greater than 125 microns (μm).

[0015] Through testing, it has been recognized that certain key areas of scaffolds that were not previously a problem when larger wall thicknesses were used to make them thinner. An example of a scaffold with a wall thickness greater than 158 microns (μm) is described in US Patent Application No. 2010/0004735. Placement of ring and link elements compared to existing bioabsorbable scaffolds (eg, from 160 micron (μm) wall thickness to 100 micron (μm) wall thickness) if a significant reduction in wall thickness is made. , Shape and dimensions have been found to require improvement, especially at the distal end of the scaffold.

[0016] Thin-walled scaffolds are required because of the clinical need to maintain a low profile of struts exposed in the bloodstream. Blood compatibility, also referred to as blood compatibility or blood clotting resistance, is a desirable property for scaffolds and stents. Adverse events of scaffold thrombosis, although very infrequent, are associated with high morbidity and mortality. To reduce the risk of thrombosis, double antiplatelet therapy is given with all coronary scaffolds and stent transplants. This is to reduce treatment, vascular injury, and thrombus formation by the implant itself. Scaffolds and stents are foreign bodies, all of which have some degree of thrombus formation. Thrombus formation of a scaffold refers to its tendency to form a thrombus, which is strut thickness, strut width, strut shape, total scaffold surface area, scaffold pattern, scaffold length, scaffold diameter, surface. It is due to several factors, including roughness and surface chemistry. Some of these factors are interrelated. The low strut profile also leads to a reduction in neointimal hyperplasia. This is because the new lining will grow to the extent necessary to cover the struts. Covering is therefore a necessary step in completing healing. The thinner the struts, the faster the endothelialization and healing.

[0017] According to various aspects of the invention, thin-walled scaffolds (“scaffolds”), medical devices, methods for making such scaffolds, making markers, making markers scaffolding struts, There are methods for attaching to a link or bar arm, for crimping, or for assembling a medical device with such a scaffold, which may be one or more of the following (1)-(15): , Or any combination thereof.

(1) The scaffold is crimped to the theoretically minimum crimp diameter (D-min).

(2) The scaffold wall thickness is less than 125 microns (μm), less than 100 microns (μm), about 100 microns (μm), or about 93 microns (μm).

(3) The wavelength of the ring connected to the marker link is larger than the wavelength of another ring not connected to the marker link, and / or the wavelength of the ring connected to the marker link has a wavelength of a different length.

(4) The distance from the W top to the adjacent U top is larger than the distance from the Y top to the adjacent U top.

(5) The scaffold is made of a tube containing poly (L-lactide).

(6) A scaffold crimped into a balloon, the scaffold constituting the crimped state illustrated and described in connection with FIG. 4D, FIG. 6A or FIG. 7A.

(7) A method of crimping any of the scaffolds described in connection with FIG. 3, FIG. 4, FIG. 5, FIG. 6, or FIG.

(8) A method for attaching a radiodensity marker to a scaffold.

(9) A marker link illustrated and described in connection with FIG. 2C.

(10) The ring has n peaks, where n is greater than 5 or greater than 6 and less than or equal to 12.

(11) The ring has two wavelengths of the first size and n-3 wavelengths of the second size, the first size being larger than the second size.

(12) w The ring connected to the marker link at the top has a first width, and the adjacent ring connected to the marker link has a second width larger than the first width.

(13) The ring connected to the marker link at the W top has a wider flat portion than the Y top flat portion connected to the marker link and coupled to the first ring.

(14) The first distance between the marker link and the adjacent ring is greater than the second distance between the rings joined by the marker link.

(15) Non-linear link The first distance between rings joined by a marker link is greater than the second distance between rings not joined by a non-linear marker link.

(16) D-min is about 1 mm or less than 1 mm.

(17) The aspect ratio (AR) of the marker link of the thin scaffold is about 4 to 5, or about 4.5, and AR is defined as the maximum width of the marker link divided by the wall thickness of the marker link. Will be done.

(18) The first wavelength or 1/2 wavelength of the first ring is larger than the second wavelength or 1/2 wavelength of the combined second ring.

(19) The first wavelength or 1/2 wavelength between the two peaks of the ring is different from the second wavelength between the other two peaks of the same ring.

(20) The ring is sinusoidal or zigzag.

(21) In a marker link having a maximum width approximately 200% larger than the maximum width of the non-marker link, the half wavelength measured from the W top formed between the marker link and the first ring is the marker link and the first ring. It is about 15% larger than the half wavelength measured from the Y apex formed between the second ring coupled to the first ring.

(22) In a marker link having a maximum width approximately 200% larger than the maximum width of the non-marker link, the wavelength measured from the W top formed between the marker link and the first ring is the marker link and the first ring. It is about 5% to 10% larger than the wavelength measured from the top of Y formed between the ring and the second ring coupled to the ring.

(23) In a marker link having a maximum width approximately 200% larger than the maximum width of a non-marker link, the wavelength measured from the W top / mountain formed between the marker link and the ring is in the other mountains of the ring. It is about 5% to 10% larger than the measured wavelength.

(24) A top width B1 larger than a top width B2, for example, a top width B1 larger than the top width B2 by about 350% to 400%.

(25) The ring distance A12 between the first ring and the second ring is larger than the ring distance A23 between the second ring and the third ring, for example, A12 is about 40% larger than A23. ..

(26) The link is a linear link or a non-linear link. For example, link 20 and link 636.

(27) The length c1 which is about 36% larger than the length c2 of the marker link.

(28) The length c1 which is about 36% larger than the length c2 of the non-linear link.

(29) A medical device, a thin-walled scaffold having a network of multiple rings interconnected by links, each ring having multiple peaks, the peaks being U-top, Y-top and W-top. One of these, each ring has a thin-walled scaffold and a plurality of thin-walled scaffolds extending in a wavy circumferential direction along a vertical axis (BB) perpendicular to the longitudinal axis (AA). A marker link extending between the first ring and the second ring of the rings of the above, wherein the marker link contains a structure having a hole, and a radiation opaque material is contained in the hole. , The marker link forms the W apex of the first ring and the first ring, forms the Y apex of the second ring and the second ring, and the W of the first ring. The 1/2 wavelength of the first ring measured from the top to the adjacent U top in the first ring is measured from the Y top of the second ring to the adjacent U top in the second ring. A medical device that is larger than 1/2 wavelength of the second ring.

(30) The medical device according to (29), which is combined with one or more of the following items (a) to (g), or any combination thereof.
(A) The length of the marker link is greater than the length of the link connecting the second ring to the third ring coupled to the second ring.
(B) The marker link includes a first link portion extending from the structure to the W top of the first ring and a second link portion extending from the Y top of the second ring to the structure. The width of the link portion of 1 is shorter than the length of the second link portion.
(C) The length of the first link portion is smaller than the length of the second link portion.
(D) The structure includes a first hole and a second hole each containing a radiation opaque material, and the first hole and the second hole are arranged parallel to the axis AA. There is.
(E) The first ring includes the first mountain, the second mountain and the third mountain, the first mountain corresponds to the W top of the first ring, and the second mountain is the second mountain. Next to the first mountain, the third mountain is next to the second mountain, and the second wavelength extending from the second mountain to the third mountain extends from the first mountain to the second mountain. It is smaller than the wavelength of 1.
(F) The flat portion of the W top of the first ring is the flat portion of the W top of the third ring of the third ring coupled to the second ring, and / or the fourth of the first ring. It is larger than the flat part of the W top.
(G) The wavelength of the first ring forming the W apex of the first ring is longer than the wavelength of the second ring forming the Y apex of the second ring.

(31) A medical device, a thin-walled scaffold with proximal and distal ends formed by a network of multiple rings interconnected by links, each ring having multiple piles. The peak is one of the U-top, Y-top and W-top, and each ring is along a vertical axis (BB) perpendicular to the longitudinal axis (AA). A thin-walled scaffold extending in a wavy circumferential direction and a marker link extending between the first ring and the second ring of a plurality of rings, the marker link having a structure having a hole. It comprises a marker link, which contains and contains a radiation impermeable material in the hole, the marker link forming the W apex of the first ring and the first ring, the second ring and the second. Forming the Y-top of the ring, the W-top of the first ring corresponds to the first crest, measuring from the first crest to the second crest of the first ring next to the first crest. A medical device in which the first wavelength of the first ring is greater than the second wavelength of the first ring measured from the second ridge to the third ridge next to the first ring.

(32) The medical device according to (31), which is combined with one or more of the following items (a) to (c), or any combination thereof.
(A) The first ring has n peaks and n-1 wavelengths, n is at least 6 and is 12 or less, and the first wavelength and the second wavelength are the first. The first mountain is larger than the remaining n-3 wavelengths measured in the n-1 mountains.
(B) The remaining n-3 wavelengths all have the same length.
(C) The length of the marker link is approximately equal to the length of the link connecting the second ring to the third ring.

(33) A medical device, formed by a balloon catheter having a balloon with a distal balloon end and a proximal balloon end, and a network of rings interconnected by links, with the proximal end portion and the distal end. A thin-walled scaffold crimped into a balloon with an end portion, each ring having multiple peaks, the peak being one of the U-top, Y-top and W-top, where each ring is A thin-walled scaffold extending circumferentially along a vertical axis (BB) perpendicular to the longitudinal axis (AA), and a first and second of a plurality of rings. A marker link extending between the ring and the marker link comprising a structure having a hole, wherein the hole contains a radiation permeable material, the marker link comprises a marker link, and the marker link is a first. The W apex of the first ring and the first ring are formed, the Y apex of the second ring and the second ring is formed, and the W apex of the first ring corresponds to the first mountain and the first The first wavelength of the first ring measured from the mountain to the second mountain next to the first mountain is measured from the second mountain to the third mountain next to the second mountain. Larger than the second wavelength of the first ring, the thin-walled scaffold has an outer diameter of about D-min, D-min = (1 / π) × [(n × trace_width) + (m × link_width). )] + 2 * t, a medical device.

(34) The medical device according to (33), which is combined with one or more of the following items (a) to (d), or any combination thereof.
(A) The maximum width of the structure measured along the axis BB is greater than the maximum width of the link extending between the second ring and the third ring coupled to the second ring.
(B) The marker link includes a first link portion extending from the structure to the W top and a second link portion extending from the Y top to the structure, and the width of the first link portion is the second. Larger than the width of the link part.
(C) The length of the first length portion is smaller than the length of the second link portion.
(D) The structure includes a first hole and a second hole containing a radiation opaque material, and the first hole and the second hole are arranged parallel to the axis AA. ..

(35) A method for making a medical device, in which a tube containing poly (L-lactide) is used and a thin-walled scaffold pattern is formed from the tube, and the thin-walled scaffold is linked. Formed by a network of multiple rings interconnected by, with proximal and distal ends, each ring having multiple peaks, the peaks of the U-top, Y-top and W-top. One of them, each ring extends radially circumferentially along a vertical axis (BB) perpendicular to the longitudinal axis (AA), with multiple thin-walled scaffolds. With the step of forming a thin scaffold pattern comprising at least one marker link extending between the first ring of the ring and the second ring coupled, the marker link comprising a structure having a hole. , A step of placing a radiodensity material in a marker hole, the hole having a first size before material placement and a second size after material placement, which is larger than the first size. The structure includes a step of placing a radiodensity material having a width measured along the axis BB and a step of crimping the thin-walled scaffold into a balloon catheter, and the thin-walled scaffold is almost theoretical. A method in which the top is crimped to the smallest crimp diameter (D-min) and neither the top of the top nor the top of the structure overlaps the structure.

(36) The medical device according to (35), which is combined with one or more of the following items (a) to (c), or any combination thereof.
(A) The marker link forms the W apex of the first ring and the first ring, forms the Y apex of the second ring and the second ring, and the W apex of the first ring is the first. Corresponding to the mountain, the first wavelength of the first ring measured from the first mountain to the second mountain next to the first mountain is the third mountain next to the second mountain. Greater than the second wavelength of the first ring measured up to.
(B) The marker link forms the W apex of the first ring and the first ring, forms the Y apex of the second ring and the second ring, and forms the first U apex and the second U apex. Are next to each other above and below the W apex of the first ring, the first strut extends from the W apex of the first ring to the first U apex, and the second strut is the first ring. The distance between the first U top and the second U top, or the distance from the second strut to the first strut, extends from the W top to the second U top. It is greater than or equal to the maximum width of the marker structure measured along.
(C) The width of the marker structure is greater than the maximum width of the link connecting the second ring to the adjacent third ring.

(37) A medical device, a thin-walled scaffold having a proximal end portion and a distal end portion formed by a network of rings interconnected by links of the thin-walled scaffold, each ring. Has a plurality of apex including a U apex and at least one of a Y apex and a W apex, each ring having a vertical axis (BB) perpendicular to the longitudinal axis (AA). ), With a thin-walled scaffold extending circumferentially along the), the proximal end portion containing the outermost proximal ring coupled to the first proximal ring by the first proximal link. , The first proximal ring was attached to the second proximal ring by a second proximal link, and the distal end portion was attached to the first distal ring by a first distal link. It contains the outermost distal ring, the first distal ring is attached to the second distal ring by a second distal link, and the first proximal link contains a radiopaque material. A medical device comprising a proximal marker link with a proximal hole, the first distal link lacking a link holding a radiopaque material.

(38) The medical device according to (37), which is combined with one or more of the following items (a) to (i), or any combination thereof.
(A) The outermost proximal ring is attached to the first proximal ring only by the first proximal link, two of the first proximal links with respect to axis AA. It extends in parallel and has a constant moment of inertia of area.
(B) The outermost distal ring is attached to the first distal ring only by the first distal link, each of which is a non-linear link strut.
(C) The proximal marker link has a first end and a second end, the first end forming the outermost proximal ring and one of the W and Y apex. , Forming the first proximal ring and the other of the W and Y apex.
(D) The first distal ring and the second distal ring are connected by a distal marker link.
(E) The distal marker link comprises a structure surrounding the two holes, the first distal ring and the second distal ring are further coupled by one or more marker links.
(F) The distal marker link has a first end and a second end, the first end forming the first distal ring and one of the W and Y apex. , The second distal ring forms the other of the W and Y apex, with the W apex wider than the Y apex.
(G) Proximal marker links are peripheral edges that generally surround the hole and define the hole wall and strut perimeter, where the distance between the wall and the perimeter is D, the perimeter and the radiodensity placed in the hole. Further comprising a radiodensity marker, including a head having a flange disposed on the periphery, the flange having a radial length of less than 1 / 2D to less than 1 / 2D. The thin-walled scaffold thickness (t) is related by the marker length (L) measured between the marker's antiluminal flank and the lumen flank by 1.1 ≤ (L / t) ≤ 1.8. are doing.
(H) The distal marker link forms one of the W and Y apex of the first distal ring and the second distal ring and is measured from the apex next to the first W apex. The 1/2 wavelength of the ring with the Y apex is greater than the 1/2 wavelength of the ring with the Y apex.
(I) The length of the first proximal link is shorter than the length of the first distal link and / or the length of the second distal link is smaller than the length of the first distal link.

(39) A medical device, formed by a balloon catheter having a balloon with a distal balloon end and a proximal balloon end, and a network of rings interconnected by links of thin-walled scaffolds, the proximal end. A thin-walled scaffold crimped into a balloon with a portion and a distal end portion, each ring having a plurality of apex, including a U apex and at least one of a Y apex and a W apex. Each ring comprises a thin-walled scaffold, which extends circumferentially in a wavy manner along a vertical axis (BB) perpendicular to the longitudinal axis (AA), with a proximal end portion. Includes the outermost proximal ring, crimped to the end of the proximal balloon and attached to the first proximal ring by the first proximal link, the first proximal ring being the second proximal link. Attached to the second proximal ring by, the distal end portion is crimped to the distal balloon end, and the outermost far, connected to the first distal ring by the first distal link. The position ring is included, the first distal ring is attached to the second distal ring by a second distal link, and the first proximal link is a proximal hole containing a radiation opaque material. The first distal link lacks a link that retains the radiation permeable material, the first distal link has a non-linear link, and the thin scaffold is about D-min. A medical device having an outer diameter of D-min = (1 / π) × [(n × trace_width) + (m × link_width)] + 2 * t.

(40) The medical device according to (39), which is combined with one or more of the following items (a) to (i), or any combination thereof.
(A) The outermost proximal ring is attached to the first proximal ring only by the first proximal link, and each of the first proximal links extends parallel to the axes AA. It exists and has a constant moment of inertia of area.
(B) The non-linear link is a U-shaped link.
(C) The proximal marker link has a first end and a second end, the first end forming the outermost proximal ring and one of the W and Y apex. , The first proximal ring forms the other of the W and Y apex, and the marker link comprises a structure surrounding the hole.
(D) The first link portion of the proximal marker link extends from the W apex to the structure, the second link portion of the proximal marker link extends from the Y apex to the structure, and the length of the first link portion. Is greater than the length of the second link portion.
(E) The length of the first link portion is approximately equal to the sum of twice the ring width and the length of the strut extending between the U top and the U top, Y top or W top of the ring.
(F) The non-linear link has a first end and a second end, the first end forming the outermost proximal ring and one of the W and Y tops, the first. Forming the proximal ring of the W apex and the other of the Y apex, the non-linear link comprises a U-shaped structure between the W apex and the Y apex.
(G) The first link portion of the proximal U-shaped link extends from the W top to the U-shaped structure, the second link portion of the proximal marker link extends from the Y top to the structure, and the first link. The length of the portion is greater than the length of the second link portion.
(H) The length of the first link portion is approximately equal to the sum of twice the ring width and the length of the strut extending between the U top and the U top, Y top or W top of the ring.
(I) The distal marker link has a first end and a second end, the first end forming the first distal ring and one of the W and Y apex. , Forming the second distal ring and the other of the W and Y apex.

(41) A medical device, a thin-walled scaffold having a proximal end portion and a distal end portion, formed by a network of rings interconnected by links of the thin-walled scaffold, each ring. Has a plurality of apex including a U apex and at least one of a Y apex and a W apex, each ring having a vertical axis (BB) perpendicular to the longitudinal axis (AA). ), With a thin-walled scaffold extending circumferentially along the), the proximal end portion containing the outermost proximal ring coupled to the first proximal ring by the first proximal link. , The first proximal ring was attached to the second proximal ring by a second proximal link, and the distal end portion was attached to the first distal ring by a first distal link. It contains the outermost distal ring, the first distal ring is attached to the second distal ring by a second distal link, and the first proximal link contains a radiopaque material. It contains a proximal marker link with a pair of proximal holes, the proximal holes are located along axis AA, and the first distal link is a pair of distant links containing a radiation opaque material. Includes a distal marker link with a position hole, the distal hole being located along the axis BB.

(42) The medical device according to (41), which is combined with one or more of the following items (a) to (i), or any combination thereof.
(A) The outermost proximal ring is attached to the first proximal ring only by the first proximal link, two of the first proximal links with respect to axis AA. It extends in parallel and has a constant moment of inertia of area.
(B) The outermost distal ring is attached to the first distal ring only by a first distal marker link and a non-linear link strut.
(C) The proximal marker link has a first end and a second end, the first end forming the outermost proximal ring and one of the W and Y apex. , Forming the first proximal ring and the other of the W and Y apex.
(D) The width of the W apex formed by the first end is greater than the width of the Y apex formed by the second end, so the wavelength of the ring forming the W apex forms the Y apex. Longer than the wavelength of the ring.
(E) The distal marker link has a first end and a second end, the first end forming the outermost distal ring and one of the W and Y apex. , Forming the first distal ring and the other of the W and Y apex.
(F) The distal marker link includes a first link portion extending from the hole to the W apex and a second link portion extending from the hole to the Y apex, and the length of the first link portion is the first. It is longer than the length of the link part of 2.
(G) Proximal marker links are peripheral edges that generally surround the hole and define the hole wall and strut perimeter, where the distance between the wall and the perimeter is D, the perimeter and the radiodensity placed in the hole. Further comprising a radiodensity marker, including a head having a flange disposed on the periphery, the flange having a radial length of less than 1 / 2D to less than 1 / 2D. The thin-walled scaffold thickness (t) is related by the marker length (L) measured between the marker's antiluminal flank and the lumen flank by 1.1 ≤ (L / t) ≤ 1.8. are doing.
(H) The radiation opaque material is contained in the hole, and the radiation opaque material has the shape of a frustum.
(I) The hole comprises a first opening and a second opening located on the first side and the second side of the marker link, respectively, the first opening being larger than the second opening and the frustum. Is substantially coplanar with the first opening and the second opening.

(43) A medical device, formed by a balloon catheter having a balloon with a distal balloon end and a proximal balloon end, and a network of rings interconnected by links of thin-walled scaffolds, the proximal end. A thin-walled scaffold crimped into a balloon with a portion and a distal end portion, each ring having a plurality of apex, including a U apex and at least one of a Y apex and a W apex. Each ring comprises a thin-walled scaffold, which extends circumferentially in a wavy manner along a vertical axis (BB) perpendicular to the longitudinal axis (AA), with a proximal end portion. Includes the outermost proximal ring, crimped to the end of the proximal balloon and attached to the first proximal ring by the first proximal link, the first proximal ring being the second proximal link. Attached to the second proximal ring by, the distal end portion is crimped to the distal balloon end, and the outermost far, connected to the first distal ring by the first distal link. Including the position ring, the first distal ring is attached to the second distal ring by a second distal link, (1) the first proximal link is a proximal marker link with structure. Containing, the structure extends parallel to the axes AA and contains a radiation permeable material, (2) the first distal link comprises a distal marker link comprising the structure, the structure. Extending parallel to the axis BB, containing a radiation permeable material, the thin-walled scaffold has an outer diameter of about D-min, D-min = (1 / π) × [(n ×). Strut_width) + (m × link_width)] + 2 * t, a medical device.

(44) The medical device according to (43), which is combined with one or more of the following items (a) to (i), or any combination thereof.
(A) The outermost proximal ring is attached to the first proximal ring only by the first proximal link, and each of the first proximal links extends parallel to the axes AA. It exists and has a constant moment of inertia of area.
(B) The first distal link includes a non-linear link.
(C) The proximal marker link has a first end and a second end, the first end forming the outermost proximal ring and one of the W and Y apex. , The first proximal ring forms the other of the W and Y apex, and the marker link comprises a structure surrounding the hole.
(D) The first link portion of the proximal marker link extends from the W apex to the structure, the second link portion of the proximal marker link extends from the Y apex to the structure, and the length of the first link portion. Is greater than the length of the second link portion.
(E) The length of the first link portion is approximately equal to the sum of twice the ring width and the length of the strut extending between the U apex and the Y apex, U apex or W apex of the ring.
(F) The first distal link comprises a non-linear link having a first end and a second end, the first end being the outermost proximal ring and one of the W and Y apex. The first proximal ring forms the other of the W and Y apex, and the non-linear link comprises a U-shaped structure between the W apex and the Y apex.
(G) The first link portion of the nonlinear link extends from the W top to the U-shaped structure, the second link portion of the nonlinear link extends from the Y top to the U-shaped structure, and the length of the first link portion. Is greater than the length of the second link portion.
(H) The length of the first link portion is approximately equal to the sum of twice the ring width and the length of the strut extending between the U apex and the Y apex, U apex or W apex of the ring.
(I) The hole in the distal marker link is between the U apex next to the W apex of the outermost distal ring and the U apex next to the Y apex of the first distal ring. There is no overlap or overlap.

[Invitation by reference]
[0018] All documents and patent applications described herein are herein by reference, as if each individual document or patent application was specifically individually indicated to be incorporated by reference. It is to be used in. As long as there are conflicting usages of the terms in the incorporated literature or patent and the specification, those terms have the meaning consistent with the usage in which they are used herein.

The scaffold is shown in a crimped state (balloon not shown), a perspective view of a portion of the prior art scaffold. FIG. 3 is an upper partial view of a scaffold showing a marker link that has holes for holding radiodensity material and connects adjacent rings. FIG. 2 is a duplicate of FIG. 2 showing additional dimensional characteristics and / or features of a link for holding two markers. It is a figure which shows the alternative embodiment of a marker link. FIG. 2 is another duplicate of FIG. 2 in which the marker is attached to the link. FIG. 2 shows a distal end portion and a proximal end portion of a scaffold according to an embodiment, including a marker link for the connecting ring of FIG. It is a figure which shows the section IIIA of the scaffold of FIG. It is a figure which shows the section IIIB of the scaffold of FIG. It is a figure which shows the scaffold of FIG. 3 in a crimp state. It is a figure which shows the scaffold of FIG. 3 crimped to the balloon of a balloon catheter. The end portion connects the adjacent rings and contains a link containing a marker, the ring has a W apex partially formed by the marker link, and the W apex has been modified to correspond to the marker structure. It is a figure which shows the end part of the scaffold by another embodiment. It is a figure which shows the section IV plane of the scaffold of FIG. To show the difference between the two rings, the distal end ring of the scaffold of FIG. 3 is shown with the distal end ring of the scaffold of FIG. 4 shown dotted. It is a figure which shows the section IVC of the scaffold of FIG. It is a figure which shows the scaffold of FIG. 4 in a crimp state. FIG. 3 is a partial view of the distal end portion of the scaffold according to another embodiment. A scan according to another embodiment in which the distal end portion is different from the proximal end portion, the non-linear link strut connects the outermost distal ring to the medial ring, and the marker link is between the medial rings at the distal end portion. It is a figure which shows the end part of a fold. FIG. 6 is a partial view of the scaffold of FIG. 6 in a crimped state. It is an image of the distal end of a catheter in a flexed form showing the distal ring of the scaffold flaring or protruding outward from the distal end of the balloon. FIG. 6 is an image of the distal end of a catheter in a flexed form showing the distal ring of the scaffold according to FIG. 6, where the distal end ring no longer flares out when the catheter is placed in a flexed state. In the figure showing the end portion of the scaffold according to another embodiment in which the proximal end portion is different from the distal end portion and the nonlinear link strut and the modified marker link connect the outermost distal ring to the medial ring. be. FIG. 7 is a partial view of the scaffold of FIG. 7 in a crimped state. FIG. 7 is a partial view of the scaffold of FIG. 7 taken in section VII of FIG. FIG. 7 is an image of the distal end of a catheter in a flexed form showing the distal ring of the scaffold according to FIG. 7, where the distal end ring does not flare outward when the catheter is placed in the flexed state. It is a side view of the marker by another embodiment. It is a top view of the marker by another embodiment. FIG. 3 is a cross-sectional view of a link having a hole and having the markers of FIGS. 8A-8B embedded in the hole. It is a side sectional view of the 1st die for forming a rivet marker from a radiation opaque bead. It is a side view of the rivet marker formed by using the die of FIG. FIG. 11A is a side cross-sectional view of the scaffold strut after the marker has been deformed to create a peripheral edge and a lower peripheral edge that hold the marker in the hole during the forming process, where the marker is engaged with the hole in the strut. be. It is a side sectional view of the 2nd die for forming a rivet marker from a radiation opaque bead. It is a side view of the rivet marker formed by using the die of FIG. It is a perspective view which shows one aspect of the process for deforming a rivet packed in a scaffold hole to strengthen the engagement with a hole to resist the drop force associated with crimp or balloon expansion. FIG. 3 is a perspective view illustrating another aspect of the process for deforming a rivet packed in a scaffold hole to enhance engagement with the hole to resist the drop force associated with crimp or balloon expansion. FIG. 3 is a perspective view illustrating yet another embodiment of the process of deforming a rivet packed in a scaffold hole to enhance engagement with the hole to resist the drop force associated with crimp or balloon expansion. 14A is a side sectional view of a modified rivet marker and scaffold hole after the steps described in relation to FIGS. 14A-14C. It is a figure of the deformed marker shown in FIG. 15A. FIG. 15A is a side sectional view of the rivet and marker hole of FIG. 15A after the heating step. FIG. 6 illustrates the steps associated with removing the formed rivet marker from the die and placing the rivet marker in the hole in the scaffold. FIG. 6 illustrates the steps associated with removing the formed rivet marker from the die and placing the rivet marker in the hole in the scaffold. FIG. 6 illustrates the steps associated with removing the formed rivet marker from the die and placing the rivet marker in the hole in the scaffold. It is a figure explaining the process for crimping the thin-walled scaffold by this disclosure. It is a figure explaining the process for crimping the thin-walled scaffold by this disclosure.

[0056] In the present specification, the similar reference numbers described in the drawings and the specification refer to corresponding elements or similar elements in different figures.

[0057] The following terms and definitions apply to this disclosure.

[0058] The terms "about," "approximately," "generally," or "substantially" are 30%, 20% more than each endpoint of the stated value, range, or stated range. %, 15%, 10%, 5%, 4%, 3%, 2%, 1.5%, 1%, 1-2%, 1-3%, 1-5%, or 0.5-5% Only less or more, less or more, or 1 sigma, 2 sigma, 3 sigma variance (Gaussian distribution) from the stated mean or expected value. For example, d1 is about d2 when d1 is 30%, 20%, 15%, 10%, 5%, 4%, 3%, 2%, 1.5%, 1%, 0% or 1 to. It means that it differs from d2 by 2%, 1 to 3%, 1 to 5%, or 0.5 to 5%. When d1 is the mean, d2 is about d1 means that d2 is within the variance or standard deviation of 1 sigma, 2 sigma, or 3 sigma from d1.

[0059] Any numerical value, range, or range endpoint preceded by the word "about," "approximately," "generally," or "substantially" in the present disclosure (eg, "approximately". "Nothing", "almost nothing", "almost all", etc.) are preceded by the words "about", "approximately", "generally", or "substantially". It should be understood that not the same numbers, ranges, or range endpoints are also described or disclosed.

[0060] “Glass transition temperature”, TG, is the temperature at which the amorphous domain of a polymer changes from a brittle glass state to a solid deformable or ductile state at atmospheric pressure. This application defines a method for finding a polymer TG, or TG-low (lower limit of the TG range), in the same manner as U.S. Patent Application No. 14/857635 (reference number: 62571.1216).

[0061] A "stent" generally means a permanent, durable, or non-degradable structure consisting of a non-degradable metal or alloy structure, while a "scaffold" is a living body. Temporary that contains absorptive or biodegradable polymers, metals, alloys or combinations thereof and is capable of radially supporting blood vessels for a limited period of time, eg, 3 months, 6 months or 12 months after implantation. Means a structure. However, it should be understood that the term "stent" is often used in the art to refer to either type of structure.

[0062] "Expansion diameter" or "expansion diameter" refers to the inner or outer diameter that the scaffold obtains when its supporting balloon inflates the scaffold from its crimp form in order to implant the scaffold into a blood vessel. The inflatable diameter may refer to a post-expanded balloon diameter that exceeds the nominal balloon diameter, eg, a 6.5 mm nominal balloon (ie, 6.5 mm nominal diameter when inflated to a nominal balloon pressure such as 6 times atmospheric pressure). The post-expanded diameter of the balloon) is about 7.4 mm, and the post-expanded diameter of the 6.0 mm balloon is about 6.5 mm. The nominal to post-expansion ratio of the balloon can range from 1.05 to 1.15 (ie, the post-expansion diameter may be 5% to 15% larger than the nominal inflatable balloon diameter). The scaffold diameter is primarily associated with the recoil effect associated with any or all of the methods in which the scaffold was manufactured and processed, the scaffold material and the scaffold design, after obtaining the inflatable diameter by balloon pressure. Due to this, the diameter decreases to some extent.

[0063] The term diameter shall mean inner or outer diameter unless otherwise specified or otherwise implied in the context of the description.

[0064] When we say scaffold struts, it also applies to links and bar arms.

[0065] The "post-dilation diameter" (PDD) of a scaffold refers to the inner diameter of the scaffold after it has increased to its dilated diameter and the balloon has been removed from the patient's vasculature. PDD considers the recoil effect. For example, the acute PDD refers to the scaffold diameter in consideration of the acute recoil in the scaffold.

[0066] The "pre-crimp diameter" is cut from a tube from which the scaffold was made (eg, dip coating, injection molding, extrusion, radial expansion, die stretching and / or annealing. ) Or the outer diameter (OD) of the scaffold before being crimped into the balloon. Similarly, "crimp diameter" means the OD of the scaffold when crimped by a balloon. "Pre-crimp diameter" is about 2 to 2.5 times the crimp diameter, 2 to 2.3 times, 2.3 times, 2 times, 2.5 times, 3.0 times the size, extended diameter, nominal It can be about 0.9 times, 1.0 times, 1.1 times, 1.3 times and about 1-1.5 times the diameter of the balloon, or the diameter after expansion. Crimp, as used herein, means a scaffold diameter reduction characterized by significant plastic deformation, i.e., a diameter reduction of more than 10% or more than 50% is a wavy ring pattern, eg, FIG. 1. It is attributed to plastic deformation, such as at the apex in the case of stents or scaffolds with. When the scaffold is unfolded or expanded by the balloon, the inflated balloon plastically deforms the scaffold from its crimp diameter. Methods for crimping scaffolds made in accordance with the present disclosure are described in U.S. Patent Application No. 2013/0255853 (reference number 62571.628).

[0067] Materials that "comprising" or "comprising" poly (L-lactide) or PLLA include PLLA polymers, blends or mixtures containing PLLA and other polymers, and PLLA and other polymers. Including, but not limited to, copolymers of. Thus, a strut containing PLLA means that the strut can be made from a material comprising either a PLLA polymer, a blend or mixture containing PLLA and another polymer, and a copolymer of PLLA and another polymer. ..

[0068] A bioabsorbable scaffold made of a biodegradable polyester polymer is radiation permeable. A radiodensity marker is placed on the scaffold to allow fluoroscopy. For example, the scaffold described in US Pat. No. 8,388,673 ('673 patent) was fixed to each end of the scaffold 200, as shown in FIG. 2 of the '673 patent. It has two platinum markers 206.

[0069] When referring to a direction perpendicular to axis AA or parallel to axis AA (eg, as shown in FIG. 3), it is relative to the scaffold or tube axis direction. It means that it is vertical or parallel to / with the axial direction. Similarly, when referring to a direction perpendicular to axis BB (eg, as shown in FIG. 3) or parallel to / with axis BB, it is in the circumferential direction of the scaffold or tube. On the other hand, it means that it is vertical or parallel to / with the circumferential direction. Thus, the scaffold sinusoidal ring extends (periodically) parallel to / with the circumferential direction, or parallel to axis BB, perpendicular to axis AA, and the other link. In one embodiment, it extends in the axial direction of the scaffold or tube or parallel to the axes AA and perpendicular to the axes BB.

[0070] Whenever the same element number is used in more than one drawing, unless otherwise stated, the same description as originally used for the element in the first drawing is given in later drawings. Please understand that it applies to the form.

[0071] Thickness dimensions (eg, wall, strut, ring or link thickness) refer to dimensions measured perpendicular to both axis AA and axis BB. Width dimensions are measured in the plane of axes AA and axes BB. More specifically, the width is the cross-sectional width from one side to the other side of the continuous structure, so that the U-shaped link 636 has exactly the same link width as the link 334. It has a constant link width over its length. Furthermore, the planes of the so-called axes AA and BB are technically not planes because they describe the surface of a tubular structure having a central lumen axis parallel to the axes AA. I want you to understand. Therefore, axis BB may, as an alternative, be considered as an angular component when the scaffold position is described using a cylindrical coordinate system (ie, axis AA is the Z axis and the top. , Links, rings, etc., can be found by angular and radial coordinate constants).

[0072] "thin wall thickness", "thin wall scaffold", "thin wall" means struts, rings, made of polymers containing poly (L-lactide) and having a wall thickness of less than 125 microns (μm). Refers to a link or bar arm. Here we discuss the challenges faced when dealing with thin-walled scaffolds, including holding markers with the same volume of radiodensity material.

[0073] FIG. 2 is a top view of a polymer scaffold, eg, a portion of a polymer scaffold having a pattern of rings interconnected by links. The marker link 20 (“link 20”) extends between the rings 312a and 312b in FIG. 2. The link 20 forms left and right structures or strut portions 21b and 21a for holding the radiodensity marker, respectively. The marker can be held in the hole 22 formed by the structures 21a, 21b. The surface 22a corresponds to the antiluminal side surface of the scaffold.

[0074] FIG. 2A is a duplicate of FIG. 2 showing additional dimensional features, particularly characteristic dimensional features D0, D1 and D2. The diameter of the hole 22 is D0. The distance between the adjacent holes 22 is D1 or more. The width of either or both edges of the hole 22, i.e., the distance from the inner wall surrounding the hole 22 to the edge of the link 20 is D2 or greater.

[0075] In FIG. 2B, the dimensions described in connection with FIG. 2A for a marker link 720 in which structures 21a, 21b are placed so as to be offset along axis BB rather than axis AA. Shows the characteristics. The marker 720 connects the ring 312a and the ring 312b. The scaffold that embodies this marker is shown in FIG.

[0076] FIG. 2C shows a rivet-type marker 127'/ 137' fixed in the hole 22. The dimensions indicated are to assess the ability of the marker link to resist the forces that tend to cause the rivet 127'/ 137' to fall out of the hole 22 (after the radiodensity material has been coupled). Refers to the parameters that can be used to inspect. These shedding forces can be caused by deformation of the pressurized balloon surface or nearby scaffold structure that tends to deform the hole 22 as the scaffold is crimped or balloon expanded. According to one embodiment, the rivet head and / or rivet tip of the rivet 127'/ 137'pair can be inspected to determine if the minimum distances δ1, δ2 and δ3 (FIG. 2C) are met. .. The distances δ1, δ2, and δ3 reflect either or both of the minimum size of the head and / or tip of the rivet pushed into the hole, which size should hold the rivet in the hole 22. There are problems (such as balloon puncture and vascular irritation when the scaffold is implanted in a blood vessel) due to excess rivet material (the head or tip diameter is too small to resist falling force). It indicates both that it does not cause. According to embodiments, the minimum distance from the end of the marker head / tip to the edge of the strut (or link) portion 21a / 21b, ie δ2, is up to about 10%, 25% and up to 50% of D2. Can be. Above 50% means that the head or tip is too small to hold the rivet in place. At the head / tip above D2, the head may or may extend beyond the edges of the struts / links, which can damage the balloon or irritate adjacent tissue. It can lead to problems such as forming relatively sharp edges. The minimum distance between the marker head / tip, ie δ1, is 0% or up to 25% of the distance D1. If the margins or heads of the markers overlap each other, this can exceed the maximum height required for struts (about 160 microns (μm)). The minimum length of the head / tip extending to the right or left of the hole 22, ie δ3, is greater than 50% of D2.

[0077] A method for inserting a radiodensity marker into a hole generally utilizes a cylindrical hole to hold the marker. Most of the holding power comes from the friction between the wall and the marker material. The marker material is reliably retained in the scaffold hole in this way when the scaffold has a wall thickness of 150 microns (μm) or greater. However, if the wall thickness is reduced to less than 100 microns (μm) or less than 100 microns (μm), it becomes much more difficult to retain the marker material in the holes. Coatings such as everolimus / PDLLA tend to be very thin, on the order of 3 microns (μm), although the coating material for carrying the drug may help hold the marker in place. This limits the out-of-plane shear strength that resists the marker falling out of the hole.

[0078] There are some desirable properties or abilities that result from reduced wall thickness of scaffold struts. Benefits of using thinner wall thickness include lower profile, thus better introducibility, reduced acute thrombus formation, and potentially improved healing. In some embodiments, it is desirable to use markers of the same size for scaffolds with thinner struts so that there is no difference, or reduction, in radiodensity between the two types of scaffolds. However, reducing the strut thickness while keeping the marker holes 22 the same size can result in the markers projecting above and / or below the strut surface due to the reduced hole volume. It is desirable to keep the marker's antiluminal flank 25a and lumen flank 25b coplanar with the corresponding antiluminal flank and lumen flank of the strut, in which case the hole 22 diameter (d) is of the thinner strut. It can be increased to partially compensate for the resulting decrease in hole volume.

[0079] In paragraphs [0073]-[0083] of U.S. Patent Application No. 14 / 738,710, which the present application and the inventor have in common, factors affecting the ability of the scaffold to hold the marker in the hole. And the special challenges faced when the wall thickness is less than 160 microns (μm) or less than 125 microns (μm). According to some embodiments, if the wall thickness is less than 125 microns (μm), i.e. the scaffold is thin, the marker is reliably held in the hole solely by friction. It turns out that it cannot be done. In a preferred embodiment where the wall thickness is less than 100 microns (μm), the marker material is a rivet-shaped marker, which is briefly described above in connection with FIG. 2C and described in more detail in connection with FIGS. 8-16. Used to hold in the hole.

[0080] Hereinafter, an embodiment of a scaffold pattern suitable for satisfying one of the following purposes or a combination thereof will be described.
(I) To thin the crimp profile of the thin scaffold that supports the radiodensity marker.
(Ii) Fixing the radiodensity marker in a thin-walled scaffold.
(Iii) To reduce strain energy accumulation in the marker retention structure when the thin scaffold is deformed during crimping, balloon dilation at the target vessel site, or introduction of the scaffold to the target site.
(Iv) Avoiding protrusion or flaring of the end ring at the distal end of the scaffold for thin-walled scaffolds, or scaffolds containing PLLA and having a wall thickness greater than 125 microns (μm).

[0081] It will be appreciated that the above objectives are interrelated and that one change can address multiple objectives. For example, by making the marker link more flexible, both the purpose (iii) and the purpose (iv) can be satisfied. Scaffolds according to these embodiments may be made from thin-walled tubes or sheets of material containing poly (L-lactide) (PLLA), such thin-walled tubes or sheets producing the patterns shown in FIGS. 3-7. For laser cutting from the tubular body. The method of making the tube is one or more of extrusion, injection molding, solid phase treatment, and biaxial expansion as described in US Patent Application No. 14 / 810,344 (62571.212). Can include.

[0082] The scaffold according to the embodiment, eg, scaffold 300, 400, 500, 600 or 700, is preferably crimped into a balloon catheter as shown in FIG. 3D. Scaffold refers to any of the crimping methods described in U.S. Patent Application No. 2013/0255853, specifically paragraphs [0068]-[0073], U.S. Patent Application No. 2013/0255853. [0077]-[0099], [0111]-[0126], [0131]-[0146] and FIGS. 1A, 1B, 4A, 4B, 5A, 5B, 8A and 8B. Any of the crimping methods and devices for crimping may be attached to the balloon to ensure the desired crimp diameter, such as D-min (defined below).

[0083] FIG. 3 shows a scaffold according to an embodiment, that is, a partial plan view of an end portion of the scaffold 300. The left or distal end portion 302 (ie, the left side of FIG. 3) includes the sinusoidal rings 312a, 312b and 312c, with ring 312a being the outermost ring. The ring 312a and the ring 312b are coupled by two links 334 and a marker link 20. The ring 312c and the ring 312d are connected by three links 334 extending parallel to the axes AA. The link 334 extends parallel to the axes AA and has a constant moment of inertia of area over its length, which is because the link 334 has a constant width and thickness and the center of gravity of the link. Or the position of the geometric center (or longitudinal axis) means that it is parallel to the axis AA everywhere. The right or proximal end portion 304 (ie, the right side of FIG. 3) includes sinusoidal rings 312d, 312e and 312f, with ring 312f being the outermost ring. The ring 312d and the ring 312e are connected by three links 334. The ring 312e and the ring 312f are connected by two links 334 and a marker link 20. Thus, the scaffold 300 has a marker link 20 that extends between the outermost link and the adjacent inner ring and joins the outermost link with the adjacent inner ring. The scaffold 300 may have 15, 18 or 20 rings 312 interconnected with each other by a link 334.

[0084] Ring 312, for example ring 312b, is sinusoidal, most due to a sinusoidal wave whose curvature along the axis BB is equal to the wavelength of the sinusoidal wave equal to the distance between adjacent peaks 311a of the ring. It means that it is well explained. The ring has a constant width at both the apex 307, 309, 310 and the strut 330 connecting the apex to the adjacent apex.

[0085] Each inner ring 312b to 312e has three types of apex: U apex, Y apex, and W apex. The outermost ring has only Y-top type or W-top type and U-top type. A peak or peak 311a (or valley or valley 311b) can correspond to a U-top, a Y-top or a W-top. The outermost ring 312a has only a U-top type and a W-top type. The outermost ring 312f has only a U-top type and a Y-top type. The marker link 20 joins the rings by forming a W apex with a first ring (eg, ring 312e) and a Y apex with a second ring (eg, ring 312f).

[0086] The link 334 connects to the ring 312f at the Y top 310. The "Y apex" refers to the apex where the angle extending between the strut 330 of the ring 312 and the link 334 is an obtuse angle (greater than 90 degrees). The link 334 connects to the ring 312a at the W top 309. The "W crest" refers to a crest where the angle extending between the strut 330 and the link 334 is an acute angle (less than 90 degrees). The U top 307 is a top to which the link is not connected. The marker link 20 is connected to the ring at the W top 314 and the Y top 316.

[0087] In the scaffold 300, there are 6 peaks or peaks 311a and 6 valleys or valleys 311b for each ring 312. Mountain 311a is always followed by valley 311b. The ring 312b has twelve tops, three of which are W tops 309, three of which are Y tops 310, and six of which are U tops 307.

[0088] FIGS. 3A and 3B show partially enlarged views of the scaffold 300. 3A shows section IIIA of FIG. 3 and FIG. 3B shows section IIIB of FIG. The following description is given with respect to FIGS. 3A to 3B, with the understanding that the link 20 is connected to the outermost ring 312f at the Y top 316 and to the adjacent ring 312e at the W top 314. , The same applies to portions 302 and 304 of the scaffold 300.

[0089] Referring to FIG. 3A, the continuous wavelength of the outermost ring 312a has a length L1 and a length L2, i.e., the distance (along the axis BB) from the top 314 to the U top 307. Is L1, and the distance from the U top 307 to the Y top 309 is L2. The same distance applies to the ring 312b, where the apex 316 to the W apex 309 and the W apex 309 to the Y apex 310 are L1 and L2, respectively. In the scaffold 300, L1 = L2 = constant for the rings 312a and 312b. That is, the distance or wavelength from one mountain to another is the same. Further, in the scaffold 300, L1 + L2 are also constant everywhere. That is, for all rings, the distance between the W and Y tops is the same as the distance between adjacent mountains of rings 312a to 312f. The distance X in FIG. 3A refers to a half period or half the length of the sine wave, that is, 1/2 of L1. The distance X is equal to the distance from the top 314 to the U top 307 of the adjacent top 312a. X is the same for the ring 312b. In other embodiments, L1 is not equal to L2 and X is different for the outermost ring 312a and the adjacent ring 312b.

[0090] In an alternative embodiment, including the scaffold 400, scaffold 500 or scaffold 700 described below, the ring may be zigzag rather than sinusoidal. An example of a zigzag shaped ring is described in FIGS. 5A and 6A of U.S. Patent Application No. 2014/0039604. The zigzag ring can be described as a non-curved strut element concentrated on the apex shaped to have an inner apex radius and an outer apex radius. The same description applies, i.e., the ring can be described in terms of wavelength, struts and apex, except that the shape is zigzag rather than sinusoidal. The term "wavy" refers to both zigzag and sinusoidal rings.

[0091] With reference to FIG. 3B, the distance along the axis AA from the peak or peak of the ring 312a to the peak or peak of the adjacent ring 312b, i.e. the length of the marker 20 (plus width t1) is A12. be. The distance along the axis AA from the peak or peak of the ring 312b to the peak or peak of the adjacent ring 312c, i.e. the length (plus width t2) of the marker 334 between these rings is A23. In the scaffold 300, A12 = A23. The width of the link 20 on the left side of the marker structure 21a is tm1, and the width of the marker link 20 on the right side of the structure 21b is tm2. The width of the link 334 is tl1. The tops 307, 310, 309, 314 and struts 330 of the ring 312a have a constant width t1. The tops 307, 310, 309, 314 and struts 330 of the ring 312b have a constant width t2. The tops 307, 310, 309, 314 and struts 330 of the ring 312c have a constant width t3. In the scaffold 300, t1 is less than t2 and t2 = t3. Dimensions B1 and B2 are the top surface of the rings 312a and 312c extending parallel to the axes BB, or the non-curved, i.e., flat top surface portion. In the scaffold 300, B1 = B2.

[0092] With reference to FIG. 3C, a scaffold 300 with a crimped marker 20 is shown. The crimp diameter performed on the scaffold 300 is the same top when the scaffold is fully crimped, i.e. when the scaffold is removed from the crimping device or placed in the restraint sheath immediately after crimping. The theoretically smallest crimp diameter at which the struts that concentrate on the contact with each other. The formula for the theoretically minimum crimp diameter (D-min) under these conditions is shown below.
D-min = (1 / π) x [(n x straight_width) + (m x link_width)] + 2 * t
And during the ceremony,
"N" is the number of struts in the ring (12 struts in the scaffold 300).
"Strut_width" is the width of the strut (170 microns (μm) for the scaffold 300).
"M" is the number of links connecting adjacent rings (3 in Scaffold 300).
“Link_width” is the width of the link (127 microns (μm) for the scaffold 300).
“T” is the wall thickness (93 microns (μm) for the scaffold 300).

Therefore, in the scaffold 300, D-min = (1 / π) × [(12 × 170) + (3 × 127)] + 2 × (93) = 957 microns (μm).

[0094] With the coupled ring pairs 312a and 312b at the distal end 302 and the coupled ring pairs 312e and 312f at the distal end, the marker link 20 is from the link 334 to accommodate the marker (axis B). -Wide (along B). As a result, the adjacent struts 330 can often overlap with the link 20 to achieve the same D-min throughout. This state is shown in FIG. 3C. Such a condition of the crimped scaffold raises concerns about the local strength of the ring and link holding the marker. As shown in FIG. 3C, struts 330a, 330b and / or overlaps by the associated U apex associated with these struts (struts push the antiluminal flank of the marker) or underlaps (struts push the marker's lumen). (Pushing the surface) exists. It is preferable to eliminate this overlap / overlap when the scaffold is crimped.

[0095] Scaffold struts, especially thin-walled scaffold struts and links, are not designed to twist or support large twists. Twisting occurs when the struts touch each other and overlap. The higher the width-to-thickness aspect ratio of the scaffold strut, the greater the tendency for the strut to twist when in contact with the adjacent structure, eg, structure 21a of the marker link 20 (thin-walled scaffolds are thicker). Has a higher aspect ratio, strut width for the same vascular tissue coating compared to meat scaffolds). As can be seen from the deformed state of FIG. 3C compared to FIG. 3, twists are introduced into the ring structure and, in some cases, to the marker link struts. This type of anomalous deformation can lead to crack propagation or reduced fatigue life of the ring and / or link 20 during balloon dilation within the blood vessel.

[0096] FIG. 3D shows a medical device comprising a balloon catheter and a scaffold 300 crimped onto the balloon 15. The distal end 302 of the scaffold 300 is closest to the distal end 17b of the balloon 15, and the proximal end 304 is closest to the proximal end 17a of the balloon. The tip or distal end 12 of the balloon catheter is shown. A guide wire or mandrel 8 extends from the tip 12 and exits the lumen of the catheter shaft 2. The scaffold crimped into the balloon (according to D-min or other minimum crimp diameter) can be the scaffold 300 or scaffold 400 discussed below. Instead of the scaffold 300, a scaffold 500, a scaffold 600, and a scaffold 700 may be used.

[0097] As mentioned above, they are similar when compared to scaffolds with a relatively thick wall, such as the scaffolds described in U.S. Patent Application No. 2010/0004735 and the ABSORB GT1 bioabsorbable scaffolds. Thin-walled scaffolds with a scaffold pattern were found to exhibit a significantly higher incidence of strut overlap or underlap (hereinafter referred to as MBOL), as shown in FIG. 3C. MBOL incidence is likely to be high if the width of the link containing the marker is widened to accommodate the same total volume of marker material used in scaffolds with thicker struts. be. MBOL can also be higher when more aggressive crimps are used, for example with a D-min crimp profile.

[0098] Further, if the same volume of marker beads is attached to both the thin and thick scaffolds and the markers are coplanar with the antiluminal and luminal sides of the link, then the marker bead region A flat, wide-ranging shape must be used, and this forced shape deforms the structures 21a and 21b, increasing the tendency for strut overlap in the marker bead region. This is because the marker structure will have a higher aspect ratio to accommodate the marker and / or strain from the marker embedding process may remain, which causes the marker structure 21 to be out of plane. This is because it is more susceptible to twisting. Table 1 summarizes these findings.

[0099] In paragraphs [0073]-[0083] of U.S. Patent Application No. 14 / 738,710, which the present application and the inventor have in common, factors affecting the ability of the scaffold to hold the marker in the hole. And the special challenges faced when the wall thickness is less than 160 microns (μm) or less than 125 microns (μm). In addition, in the '710 application, the marker remains coplanar with the antiluminal flank of the strut, if necessary (thus, it has a higher aspect ratio and is more prone to twisting and overlapping during crimping. It also explains how much the width of the marker holding structure should be widened with the same radiodensity material volume as the thinned wall thickness (higher). The wider and flatter the marker structure increases the link width to wall thickness aspect ratio (AR), which increases the likelihood that the link will twist when in contact with the adjacent strut or top.

[0100] In one example, the Marclink aspect ratio (AR) of a thin scaffold with a wall thickness of 93 microns (μm) is, for example, as described in US Patent Application No. 2010/0004735. Compared to scaffold AR with a larger wall thickness of 158 microns (μm), at about 4.5 when the same volume of marker material is retained in both 93 micron and 158 micron marker structures. There is (AR = ts / t = 419 microns (μm) / 93 microns (μm) = 4.5). For scaffolds where all thicknesses are 158 microns (μm), the AR is about 2 (AR = ts / t = 322/158). Therefore, when the wall thickness is reduced from 158 microns (μm) to 93 microns (μm) with the same volume of marker material, AR increases 2.5 times. Given this significant increase in aspect ratio, the marker link tends to twist when it comes into contact with the adjacent strut or top during crimping, and / or the strut tends to overlap / overlap with the marker link. It will be understood that it can be understood.

[0101] It is known that during crimping, the angle of the scaffold bar arm decreases and the adjacent bar arm strut moves naturally towards the link at the top of the w. In this crimp event, the "outer radius" of the apex and its center point (usually located outside the link) play an important role in guiding the crimping of the scaffold struts. In fact, the center point of this outer radius tends to act as a pivot point that induces the initial behavior of the strut and limits the degree of strut movement towards the marker linkage. In this second point, the MBOL that occurs between the strut and the marker linkage is closely related to this lateral radius and the position of the pivot point. In the case of the w-top with the marker link 20 and the thin scaffold design, the center point of the w-top was initially positioned within the marker structure 21 region. Therefore, during crimping, the strut closure behavior was not kinematically restricted, resulting in frequent overlap / overlap with the marker link. In order to reduce the MBOL occurrence rate, the center point of the W top having the marker structure 21 can be moved to a region outside the marker structure 21. Thus, during crimping, as the w-top strut moves towards the marker structure 21, the strut is pushed in and slips into an overlapping or overlapping state that induces twisting of the w-top and / or link. Should avoid.

[0102] FIG. 4 shows a scaffold according to another embodiment, that is, a partial plan view of the end portion of the scaffold 400. The left or distal end portion 402 (ie, the left side of FIG. 4) includes the sinusoidal rings 412a, 312b and 312c, with ring 412a being the outermost ring. The ring 412b and the ring 312c are connected by two links 334 and a marker link 20. The ring 312c and the ring 312d are connected by three links 334 extending parallel to the axes AA. The right or proximal end portion 404 (ie, the right side of FIG. 4) includes sinusoidal rings 312d, 412b and 312f, with ring 312f being the outermost ring. The ring 312d and the ring 412b are connected by three links 334. The ring 412b and the ring 312f are connected by two links 334 and a marker link 20. Thus, the scaffold 400 has a marker link 20 that extends between the outermost link and the adjacent ring and joins the outermost ring with the adjacent ring. The scaffold 400 may have 15, 18, or 20 rings 312 interconnected with each other by a link 334.

[0103] The scaffold 400 has the same characteristics as described above for the scaffold 300, except that: Rings 412a and 412b are sinusoidal and are connected to the adjacent ring by W-tops 414 and Y-tops 416 (as in the case of rings 312a and 312e), but the rings 412a and rings near the marker 20. The ring structure of 412b has been modified to avoid strut overlap when the scaffold is crimped to the minimum theoretical crimp diameter (D-min), as described above.

[0104] With reference to FIGS. 4A and 4C, enlarged views of the scaffold 400 in Section IVA and Section IVB of FIG. 4 are shown, respectively. In order to avoid the above-mentioned overlap, the distance between the strut portion of the top of w in the marker between the ring 412a and the ring 412b is increased. This change is shown at the top 414 in the drawing. The extended apex (along the axis BB) provides more space between the strut 430 and the marker structures 21a, 21b to avoid overlap (with this change resulting). The crimp shape is shown in FIG. 4D). w The top 414 modifies the scaffold structure near the marker 20 by at least one of the following (1), (2) and (3), as opposed to the top 309 which is not associated with the marker link 20. ing.
(1) The flat, i.e., non-curved surface portion B1 of the apex exceeds the flat surface portion B2 of the other w apex 309 and increases in the direction of BB, which is, for example, the non-marker link width (tL). ) Is an increase of about 350% to about 400% with respect to the maximum width (ts) of the marker link, which is about 200% larger.
(2) The distance from the w top 414 (mountain) to the adjacent u top 407 (valley) is the distance from the y top 316 (mountain) of the ring 312b to the adjacent u top 307 (valley) and / or. Increases relative to the distance of any of the rings 312 from w-top 309 (mountain) or y-top 310 (mountain) to the adjacent u-top 307 (valley). This is shown in the figure by comparing the distance X412 and the distance X312, which are the measured lengths of the ring 412 and the ring 312 from the mountain center to the valley center, respectively. The distance X412 is about 200% larger than the non-marker link width (tL) and about 15% larger than the marker link maximum width (ts) X312.
(3) The distance from mountain 414 to the adjacent mountain 407 is greater than the distance from mountain 407 to mountain 409, that is, L1 is longer than L2 in FIG. 4A, for example, L1 is about 10% longer than L2. And / or L1 is any mountain next to the ring 312a, 312b, 312d, 312f and any next to the maximum marker link width (ts) that is about 200% larger than the non-marker link width (tL). Approximately 5% longer than the distance between.

[0105] The characteristics of the ring 412a apply equally to the ring 412b in the vicinity of the marker link 20. FIG. 4B shows a diagram of portion 302 in which the ring 412a is shown by the dotted line on the ring 312a from the scaffold 300. The distance added between the marker link 20 and the strut 430 is represented by the "increased distance" in the drawing. In this drawing, the half-period difference of the sinusoidal ring portions (X412, X312) extending between the y-top and the w-top of the marker link can also be confirmed. Also, the features of the ring 412a are symmetrical with respect to the top 414. Therefore, at least one modification of (1), (2) and (3) described above applies to both sides of the top 414.

[0106] According to another aspect of the scaffold 400 associated with "increased spacing" shown for the scaffold 400 to avoid MBOL or overlap, scaffold marker links were made to avoid overlap. However, in some embodiments connecting the rings, it is also useful to take into account the deformation of the structures 21a, 21b as the marker element, rivet or bead is placed in the hole.

[0107] FIG. 4D shows a portion of the crimped scaffold 400 in which the scaffold is crimped to D-min. As shown in the figure, the added spacing between the strut portions 430a and 430b of the top 414 of the marker link 20 also overlaps when the scaffold is crimped to the theoretically minimum crimp diameter, D-min. No underlap occurs. Specifically, in FIG. 4D, by making modifications to the ring 412 having a W-top 414 connection to the marker link 20, the struts and / or U-tops above and below the marker structure have a scaffold of D-. It has been shown that when crimped to min, they are separated by a distance greater than or equal to the maximum width (ts) of the marker structure. No overlap occurs when the scaffold with the ring 412 is crimped to D-min. The marker link is everywhere between the apex and the strut when the scaffold is crimped to about D-min.

[0108] When a thin-walled scaffold similar to the scaffold 300 followed a simulated calcified meandering anatomical model, the strut was lifted and caught on an obstacle along its path, resulting in a distal end ring. It is known that strain was observed. In addition, the marker structure 21 and the hole 22 may be deformed / stretched, resulting in the marker material falling off. To address concerns about separation of marker material from this thin scaffold, by extending the marker link and / or narrowing the width of the link portion connecting the structure 21 to the adjacent Y-top or w-top. The bending flexibility of the marker link can be increased. As a result of this change, the hinge region next to the marker structure 21 becomes more flexible, thereby localizing the deformation away from the structure 21 and protecting the marker hole 22 from significant deformation. This change also allows the distal and / or proximal ends of the scaffold to adapt more flexibly to the balloon, thereby lifting the struts and catching on obstacles while being introduced to the target site. The possibility is reduced.

[0109] FIG. 5 shows an enlarged view of another embodiment of the scaffold, namely the scaffold 500. The figure of FIG. 5 is the same as the section IVC of FIG. 4, in which the scaffold 500 has a modified marker link connecting the ring 412a and the ring 312b and a marker link connecting the ring 412b and the ring 312f. It has all the characteristics of the Scaffold 400 except. The marker link 520 differs from the marker link 20 in that an additional link 520b is added, that is, an existing link on the right side of the marker structure 21b (see marker link 20) is extended. This added or extended marker link portion results in an increase in distance A12 compared to when the marker 20 is used. Also, the distance A12 is longer than the distance A23 separating the rings not coupled by the marker links, for example the ring 312b and the ring 312c in FIG. The same modified marker link 520 that replaces the marker link 20 is made for the marker link that extends between the ring 412b and the ring 312f. The marker link 520 may be replaced with the marker link 20 of the scaffold 300 (both at the proximal and distal ends). In such cases, the same features discussed with respect to the scaffold 400 with link 520 apply to the scaffold 300 with link 520.

[0110] Replacing the link 20 with the marker link 520 causes the radiodensity material retained by the marker structure 21 to fall out of the scaffold as the scaffold is crimped, balloon expanded, or follows a meandering vessel. , Or found to be less prone to separation. The reason for the improved retention is understood by considering the strain energy distribution on the link when the scaffold is deformed or when the y-top 316 of the ring 312b moves relative to the w-top of the ring 412a. Yeah.

[0111] If the top 316 of the ring 312b moves radially outward or inward with respect to the top 414 of the ring 412a, or the top moves in the opposite direction along the axis BB, the marker link 20 deforms. do. A significant portion of the strain energy of the link 20 resulting from this deformation is retained in the marker structures 21a, 21b because the left and right link portions of the structure 21 are relatively short and thick (thus, in this portion of the marker link). There is little deformation and therefore less strain energy is retained here). The load must be rebounded somewhere along the marker link when the ring movement is forced (ie, the ring movement is due to forced displacement or overwhelming force, for example, on the scaffold of the crimp's chin. Because the ring is generated by closing, the ring will move relative to each other by a specified amount regardless of the link stiffness), so most of the strain energy is in the short, thick link area near the top. It is held in the marker structure 21 which is more easily deformed. This deformation can change the shape of the hole in which the marker material is located, resulting in loss of holding power. Retained in structure 21 by extending the link portion of the marker 20 or by adding a link 520b significantly longer than the link 520a representing the length of the link portion between the left and right sides of the structure 21 of the link 20. The strain energy is rather reduced and the strain energy held by the link 520b is higher. As a result, the marker hole 22 retains its shape during these load events, reducing the tendency of the marker material to fall off during scaffold crimping or bending. In other words, most of the deformation of the link occurs in the elongated portion 520b so that the hole 22 can retain its shape. In addition, the link 520b increases the flexibility of the link, which makes it easier for the ring 312b or the ring 312f to move relative to the ring 412a and the ring 412b, respectively. This embodiment is advantageous in avoiding the problem of the distal end ring flaring or protruding from the balloon as the catheter is routed around a dense vasculature (the above-mentioned purpose (iv)). It should also be noted that the marker 720 discussed in connection with FIG. 7 also addresses objectives (iv) and objectives (iii).

[0112] According to one example, the link 520b forming the y apex 316 has a thickness (tm2) that is approximately 60% smaller than the thickness (tm1) of the link portion 520a forming the w apex 414. In addition, the length A12 is about 27% longer than the length A23 to accommodate the link 520 with the additional link portion 520b.

[0113] When the introduction system was traced to a simulated calcified meandering anatomical model on a crimped thin-walled scaffold, the strain on the distal end ring due to the strut getting caught in an obstacle along its path. Observed. To understand the possible causes of strut catching, thin-walled scaffolds were crimped into the same morphological introduction system and placed in a flexed state similar to that present in the anatomical model observed under a microscope. It was observed that the balloon was compressed at the inner bend of the bend and tensioned at the outer bend of the bend. Under tension, the balloon stretched and adapted to the curve. If the w-top associated with the marker link is accidentally positioned on the lateral bend of the bend, the w-top will not adapt to the underlying curved balloon material at the distal end 15a, but outward. It spreads like a flare (see FIG. 6B). The w-top portion of the scaffold remains straight because it is rigid due to the marker material and structure 21.

[0114] FIG. 6 shows a scaffold according to another embodiment, that is, a partial plan view of the end portion of the scaffold 600. The left or distal end portion 602 (ie, the left side of FIG. 6) includes sinusoidal rings 312a, 412b and 312c, with ring 312a being the outermost ring. The right or proximal end portion 604 (ie, the right side of FIG. 6) includes sinusoidal rings 312d, 412b and 312f, with ring 312f being the outermost ring. As can be seen from FIG. 6, the distal end portion 602 is different from the proximal end portion 604. This modification to the scaffold 300 or scaffold 400 addresses the occurrence of an incompatible distal outermost end ring when a scaffold mounted on a balloon catheter is sent a sharp turn in the vascular system. It is something that is done.

[0115] The proximal end portion 604 of the scaffold 600 is the same as the proximal end portion 304 or the proximal end portion 404 associated with the scaffold 300 and the scaffold 400, respectively. The distal end portion 602 is modified from the distal end portion 302 or the distal end portion 402 as follows.

[0116] The (distal) marker link 20 or marker link 520 is medially distant as opposed to the (proximal) marker link 20 or 520 located between the outermost distal ring 312f and the medial ring 412b. It is located between the position end ring 412a and the medial distal end ring 312c. This change to the distal end 602 is more desirable for at least one of the following reasons (a) and (b):
(A) Improved adaptability to the distal balloon: Marker Link 20 has higher flexural rigidity than Link 634, or Link 334 for it, and thus distal from the distal end of the balloon. Can result in separation of the outermost ring. If it is not desirable to change the marker link structure, or (eg, because the structure is needed to provide sufficient surface area to hold the desired volume of radiodensity material). If not, significantly reducing the bending stiffness of the link connecting the outermost ring 312a to the inner ring 412a can be achieved by moving the marker link 20 between the inner rings. Then, the flexural rigidity between the two outermost rings 312a can be dramatically reduced (objective (iv)).
(B) Reduction of strain in marker holding structure: When the scaffold is sent a sharp turn, it is the outermost ring that receives the greatest strain due to the scaffold bending. In an embodiment of the scaffold where it is not desirable to reduce the bending stiffness of the outermost ring relative to the adjacent inner ring (eg, which can occur if the connecting link is extended to make both more flexible). When it is important to avoid a decrease in radial rigidity of the outermost ring, or to avoid an increase in spacing between the rings for drug coverage or vascular support), place the marker link 20 in the position between the inner rings. By moving, bending strain on the link 20 that may cause the marker material to fall off is avoided or reduced. That is, the bending strain of the scaffold (causing abrupt rotation of the catheter) is greater between the outermost ring and the adjacent inner ring than between the inner rings, thus changing the marker link structure. By arranging the link 20 between the inner rings (unnecessarily), the bending strain applied to the marker structure 21 is reduced. The purpose (iii) and the purpose (iii) are satisfied.

[0117] The scaffold 600 is also associated with the scaffold 300 and the scaffold 400 by the link type used to connect the outermost ring to the inner ring, i.e. the link 634 connecting the ring 312a to the ring 412a. different. The outermost distal ring 312a is coupled to the ring 412a with three nonlinear link struts 634 that have significantly higher bending flexibility than the link struts 334 connecting the inner rings. This also contributes to the reason (a) for using the scaffold 600 pattern at the distal end.

[0118] Non-linear link struts can take a variety of shapes, but with some constraints, such as providing sufficient spacing for crimps, such as the D-min crimp profile. The type shown in FIG. 6 has a U-shaped intermediate portion 636 connected to each y-top and w-top by a short linear link portion and a long linear link portion, respectively. The link portion 632a connecting the portion 636 to the w apex is longer than the link portion 632b connecting to the y apex to provide sufficient clearance for the ring struts during crimping (as described below). Since this gap is provided, in the w top portion 309 formed by the link portion 632a, the U-shaped portion 636 may interfere with the strut 330 in the crimped state, or the strut 330 may overlap with the U-shaped portion 636. It can be crimped up to D-min.

[0119] Referring to FIG. 6A, a crimp flank profile of the scaffold 600 is shown. A long linear link portion 632a and a short linear link portion 632b of the link 634 are shown together with a U-shaped intermediate portion 636. The length A12 (the length measured with respect to the axis AA) exceeds the length A23 by approximately the length of the U-shaped portion 636, or the sum of the lengths of the portion 632a and the portion 632b is the strut width of the ring. Is almost equal to A23 minus. In one example, length A12 is about 40% longer than length A23.

[0120] In another embodiment, the U-shaped portion 636 is a link having a smaller moment of inertia in the region between portions 632a and 632b, an S-shaped notch that replaces the U-shaped portion, or a narrowed portion. Can be replaced. Examples of these link types are described in U.S. Patent Application No. 2014/0039604, FIGS. 14B, 14C, 14D, 14E, and 14F, and accompanying paragraphs [0223] to [0229]. ing. By "non-linear" link strut is meant any of these links.

[0121] FIG. 6B is an image showing a deformed distal end of a medical device containing a balloon catheter with a shaft 2 and a scaffold 10 crimped onto a balloon 15. As can be seen from this figure, when the catheter is guided through a sharp turn (as it follows the guidewire), the distal end of the balloon and the shaft adapt to the turning angle, but the distal end of the scaffold. 7 does not adapt. More specifically, the outermost ring 5 flares or projects outward from the distal end. This protruding structure 5 can get caught in the walls of the vascular system. The most pressing concern with this orientation of the scaffold with respect to the distal end of the balloon is the damage that can be caused by the ring 5 getting caught in the vasculature (due to excessive bending strain) and damaging the scaffold. The possible damages have been described above. First, the marker link structure may be deformed, resulting in the dropout of the marker material. Second, strain can result in the failure of the ring 5, or breakage or crack propagation within the ring 5.

[0122] One solution to this problem is to increase the flexural rigidity of the end ring so that vascular occlusion creates space at the flared or protruding scaffold end. For example, the end ring could be made thicker or the number of connecting links between the outermost and inner rings could be increased. However, it is preferable to reduce the stiffness of the ring so that the scaffold end is more adaptable to the distal end of the balloon. It is also preferable to limit the load applied to the marker link for the above-mentioned reason. The scaffold 600 (or the scaffold 700 below) meets this requirement.

[0123] FIG. 6C is an image of the scaffold distal end 602 attached to the distal end 15a of the balloon 15 as the catheter makes similar abrupt turns in the vasculature. As shown, the end ring 312a adapts to the shape of the balloon distal end 15a by reducing the flexural rigidity of the ring 312a with respect to the inner ring (ring 312b). The end ring 312a does not flare or project as in the case of the scaffold 5. The link 632 acts as a hinge that adapts to the compression and tension that the bend should exert on the distal end ring when the crimped scaffold is placed on the bend.

[0124] Distal scaffold adaptability to the distal part of the balloon can also be achieved by modifying the marker link structure for greater bending flexibility. In practice, the w-top formed by the marker link according to this discussion can significantly reduce the stiffness at the w-top associated with the marker link 314. In that case, the thin scaffold design allows the marker link to be connected to the outermost ring without the flaring problems mentioned above.

[0125] FIG. 7 shows a scaffold according to another embodiment, i.e., a partial plan view of the end portion of the scaffold 700. The left or distal end portion 702 (ie, the left side of FIG. 7) includes the sinusoidal rings 312a, 312b and 312c, with ring 312a being the outermost ring. The right or proximal end portion 704 (ie, the right side of FIG. 7) includes sinusoidal rings 312d, 412b and 312f, with ring 312f being the outermost ring. As can be seen from FIG. 7, the distal end portion 702 is different from the proximal end portion 704. This modification to the scaffold 300 or scaffold 400 also addresses the occurrence of an incompatible distal outermost end ring when a scaffold mounted on a balloon catheter is sent a sharp turn in the vascular system. It is done to do.

[0126] The proximal end portion 704 of the scaffold 700 is the same as the proximal end portion 304 or 404 associated with the scaffolds 300 and 400, respectively. In addition, the distal end portion 702 shares some of the characteristics of the scaffold 600 in the distal end portion 602, except:

[0127] In contrast to the marker link 20 or 520 located between the inner links in the case of the scaffold 600, the marker link 720 (FIG. 2B) is located between the outermost ring 312a and the inner ring 312b. do. The marker link of the scaffold 700 is also different from the marker link of the previous embodiment. The marker link 720 has a marker structure 21 oriented vertically rather than horizontally as in the case of the marker link 20 or the link 520. That is, the marker structure 21a is offset from the marker structure 21b along the axis BB instead of the axis AA. There is a long linear link portion 732a that connects the structures 21 at one end to form the w apex 314, and a short link 732b at the opposite end that forms the y apex 316.

[0128] The outermost ring 312a of the distal end of the scaffold 702 is connected to the inner ring 312b by one marker link 720 and two non-linear links 634 used for the scaffold 600. The combined inner ring is not connected by either the marker link 720 or the link 634. Link 334 is used. The marker link 720, in contrast to the marker link 20, has higher bending flexibility due to the length of the portion 732a and is the outermost ring for easier positioning of the scaffold end under fluoroscopy. It is conveniently located between and the inner ring next to it. In addition, when the marker 720 is used, there are one or more of the following advantages function oriented: First, the marker is more flexible so that the outermost ring more easily adapts to the balloon when the catheter is sent a sharp turn in the vascular system. In this sense, the marker 720 has some of the same advantages as the marker 520 (objective (ii) and objective (iii)). Also, no changes need to be made to the ring structure to allow crimping of the ring with the w apex formed by the marker link. Since the structure 21 does not interfere with the ring structure 21, the ring 312a can be crimped to D-min (object (i)).

[0129] FIGS. 6A and 7A show the crimped state of the scaffold 700 close to the marker 720 and the link 634, and the lengths A12, A23 between the rings. As can be seen from these figures, the marker and link portions 732a and 632a allow the outer ring 312a to crimp to D-min, respectively, without interference from the U-shaped portion 636 or the marker structure 21. Has a length to do. As can be seen from these figures, the structure 21 having the hole 22 and the U-shaped structure 636 has a U top next to the W top of the left ring and a U top next to the Y top of the right ring. between.

[0130] Referring to FIG. 7B, an enlarged view of section VII of FIG. 7 is shown. As shown, the lengths of the portion 732a and the portion 732b are c1 and c2, respectively. The lengths of the portions 632a and 632b are also c1 and c2. Length A12 and length A23 of the scaffold 700 are also shown (length A12, length A23, length c1 and length c2 are also shown in the length and ring spacing of portions 632a and 632b of the scaffold 600. apply). The sum of the length c1 and the length c2 is equal to A12 minus the length of the U-shaped portion 636 and the width of the top. In some embodiments, A12 is about 40% larger than A23 and c1 is about 36% longer than c2. The length c1 is the width of the apex 314 or strut 330 subtracted from the distance between the adjacent apex valley and the apex formed by the portion 732a or the portion 632a when the scaffold is in the crimped state. Is approximately equal to (see FIGS. 6A-7A). The marker structure is located on the right side of the U apex next to the W apex formed by the marker link.

[0131] FIG. 7C is an image of the scaffold distal end 702 attached to the distal end 15a of the balloon 15 as the catheter also makes a sudden turn in the vasculature. As shown, the end ring 312a adapts to the shape of the balloon distal end 15a by reducing the flexural rigidity of the ring 312a with respect to the inner ring (ring 312b). The end ring 312a does not flare or project as in the case of the scaffold 5.

[0132] Table 2 shows the dimensions associated with the examples of scaffolds made corresponding to the illustrated scaffold embodiment (if the entry is "-", it means the same value as in the left column. Therefore, the value of tm2 of the scaffold 400 is 217, and the lengths B1 of the scaffold 500 and the scaffold 700 are 374 and 78, respectively).

[0133] With reference to Table 2, as understood from the above example, the scaffold through the crimp and / or tortuous artery as described above with respect to the scaffold 300 compared to the scaffold 400, 500, 600, 700. Wavelength, 1/2 wavelength, marker link thickness, length, and orientation, non-marker link type and length, ring spacing, and top width at the marker link, respectively, as required in relation to the introduction of has been changed. These relationships apply to thin-walled scaffolds, whether in the crimped state or before the crimped form. Therefore, when referring to crimped scaffolds, the above relationship also applies. It should also be appreciated that features of the scaffold 400 and / or the scaffold 500 that differ from the scaffold 300 can be incorporated into the scaffold 600 and the scaffold 700. Alternatively, the features of the scaffold 400 and / or the scaffold 500 may not be included in the scaffold 600 and scaffold 700 patterns.

[0134] The following discussion is primarily concerned with satisfying the purpose (ii): immobilizing a radiodensity material in the scaffold holes provided by the marker structures 21a, 21b. As mentioned above, it has been discovered that thin-walled scaffolds cannot reliably hold the marker material in the marker hole due to frictional engagement with the wall of the cylindrical hole. In order to satisfy the object (ii), in a preferred embodiment, the radiodensity material provides a rivet-like marker material without interfering with any of the other purposes (i), (iii) or (iv). By implanting in the marker structure 20, 520 or 720, it is fixed to any of the scaffolds 300, 400, 500, 600 or 700. The attachment and fixation of the marker, in some embodiments, does not include the addition of any polymer, adhesive (other than the deformation that occurs during the implantation process) or the remodeling of a cylindrical hole. In a preferred embodiment, the drug polymer coating is applied after the marker has been placed in the hole.

[0135] Instead of the spherical marker 25 for a cylindrical hole, a rivet-shaped marker is used. 8A and 8B show side views and top views of the rivet-shaped marker 27. The head 28 may include the antiluminal side surface 27a or the lumen side surface 27b of the rivet 27. In the drawing, the head 28 includes the antiluminal side surface 27a. It would be preferable to have the head 28 as the luminal flank of the rivet 27 for assembly. This is because the scaffold can then be placed on top of the mandrel and the tip of the rivet deformed by an externally applied tool (such as a pin) on the side of the scaffold's antiluminal. be. The rivet 27 has a head diameter d1 and the diameter d2 of the shank 27c is substantially equal to the hole 22 diameter. The height of the head 28 is h2, which is the amount by which the head 28 extends beyond the antiluminal side surface 22a of the strut portion 21a. Although not desirable, it does not extend beyond about 25 microns (μm), i.e., head 28, or struts from about 5-10 microns (μm) to about 25 microns (μm) from the antiluminal flank 22a. Protrusion of the head extending by an amount of about 25% or less of the thickness is also acceptable. As for the deformation of the tip of the rivet, the same degree of protrusion beyond the side surface 22b of the lumen can be allowed.

[0136] With reference to FIG. 9, rivets in the hole 22 are shown. The rivet 27 is fixed to the hole 22 by the deformed tip portion 27b'. The total height h1 is preferably about 40% or about 10% to 40% or less of the thickness (t) of the strut, and the height of the tip is about the same as the height h2 of the head. The size is within 5 to 20 microns (μm) as compared with the height h2 of the head.

[0137] The rivet 27 first inserts the rivet 27 into the hole 22 from the luminal side of the scaffold so that the head 28 rests on the luminal side surface 22b of the strut portion 21a, thereby causing the strut portion 21a. Can be attached to the hole 22 of. The scaffold is then slid over the tight-fitting mandrel. With the mandrel surface pressed against the head 28, a tool (pin or the like) is used to deform the tip 27b to give rise to the deformed tip 27b'in FIG. In some embodiments, the rivet 27 may first be inserted into the hole 22 from the antiluminal side so that the head 28 rests on the antiluminal side surface 22a of the strut portion 21a. The tip 27b is inserted into the lumen or from an adjacent position on the side of the antiluminal, with the head 28 held in place by a tool or flat surface applied to the side of the antiluminal. Deformed by a tool, pin, or mandrel that penetrates the scaffold pattern. In some embodiments, the rivet 27 may be a medium entity (FIGS. 8A-8B) or a hollow body, for example, the shank is a hollow tube and the opening penetrates the head 28 of the rivet. And it is extended.

[0138] In some embodiments, the rivet is a hollow or solid cylindrical tube without a ready-made head 28. In these embodiments, the tube (solid or hollow) may first be fitted into the hole and then a tightening tool may be used to form the head and tip of the rivet. According to a preferred embodiment, there is a method for making a radiation opaque marker as a rivet and attaching the rivet to the scaffold, and a scaffold to which such a marker is attached. First, a method for producing a rivet-shaped marker from beads will be described.

[0139] As mentioned above, the head and tip of the marker are subject to external forces on the rivet, deformation of the link structure during crimping or balloon dilation, and scaffolding in the vasculature. Contributes to holding the marker in place, such as when performing. However, in some embodiments, the tip portion of the rivet 27'in FIG. 9, eg, the tip portion 27b', is absent. Instead, the shank portion of the rivet is deformed to have a trapezoidal or truncated cone shape, or to have an enlarged end (eg, rivet 137'shown in FIG. 15A). This type of marker has been found to increase resistance to prevent the scaffold from being pushed out of the strut or link hole when exposed to external forces that deform the link or strut holding the marker.

[0140] It is desirable to choose the appropriate size of beads for forming rivets. According to some embodiments, the bead size to be used, i.e. the bead volume, is the thickness (t), hole diameter (D2), distance between holes (D1) and strut of the scaffold structure to which the rivet is attached. It depends on the thickness of the periphery (D2) (eg, link struts with holes 22 in FIG. 2A or FIG. 2B). The raw material may be spherical or cylindrical. Raw materials made of radiodensity materials can be obtained from commercially available sources.

[0141] According to the present disclosure, raw material beads are used to make rivet markers for attachment to the scaffold hole 22. In a preferred embodiment, the rivet marker is attached or engaged in a scaffold hole of a thin-walled strut or link, preferably having a thickness (t) of less than about 100 microns (μm). The steps of rivet making and attachment to the scaffold can be summarized as a 6-step process.

[0142] Step 1: From the raw material, have a diameter or volume within the desired range, i.e., a diameter or volume suitable for attachment to the scaffold according to the dimensions D0, D1, D2 and t (FIG. 2B). Select a marker bead. Selection of marker beads with the desired diameter or volume, or removal of beads that are too small from the lot, can be done using a mesh sieve. A set of beads is sieved on a net sieve. Beads that do not have the smallest diameter or volume fall through the openings in the mesh sieve. Alternative methods known in the art may be used to remove unwanted beads or select beads of appropriate size.

[0143] Step 2: Place the beads selected from step 1 on the die plate.

[0144] Step 3: Cold form rivets from the beads by pushing the beads into the die plate. Reshape the beads by pushing the beads through the die (eg, using a plate, mandrel head, pin or tapered ram head) at a temperature close to the ambient temperature to reshape the beads and the shape of the die and the die that receives the beads. The rivet is defined by the volume of the beads relative to the volume of.

[0145] Step 4: Remove the formed rivet from the die plate. The formed rivet has a total length of about 190 to 195 microns (μm) and a diameter of about 300 to 305 microns (μm) and is removed using a tool with a vacuum tube. The air pressure is adjusted to grip the rivet or move the rivet away from the tip. The rivet is made by placing an opening in the tube above the head of the rivet and lowering the air pressure in the tube to attach or aspirate the head to the tip of the tube (due to the difference in pressure) and lift the rivet from the die. Will be removed from.

[0146] Step 5: With the rivet still attached to the tip of the tube, move the rivet to position it above the hole in the scaffold, place the rivet in the hole using the same tool, and then in the tool. Raise the air pressure to the surrounding air pressure. Rivets move away from the tool.

[0147] Step 6: rivets and / or holes are deformed to engage or enhance resistance to marker dropout from the holes, eg, FIGS. 14A-14C.

[0148] It will be appreciated that steps 1-6 overcome the problem of handling non-spherical beads. For example, in steps 1 to 6, the problem of aligning the spherical beads and orienting the spherical beads so that they can be placed in the holes is overcome without having to reorient the rivets after they are formed from the spherical beads. Ru.

[0149] With reference to FIGS. 16A, 16B and 16C, the formed rivet 127'(or 137') is transferred from the die 200 (or 205) to the scaffold strut hole 22 using a vacuum tool 350. The steps associated with are shown. As will be appreciated, the formed radiodensity marker 127'is extremely small, i.e. its maximum dimension is less than 1 mm, and thus the handling and orientation of the marker 127' for placement in the hole 22 is It is complicated (as opposed to placing a sphere in the hole) because the shank needs to be properly oriented with respect to the hole. Therefore, in the embedding or forging process, the tool 250 is used to remove the rivet 127'from the hole 200, FIG. 16A, the rivet 127'is kept attached to the tool and the orientation is maintained, FIGS. 16B to 16C. And then placing the rivet 127'in the hole 22a, combined with the placement in the scaffold hole according to FIG. 16C.

[0150] With reference to FIGS. 10 and 11A, a first embodiment of the present disclosure with a die 200 and a marker 127 formed using the die 200 is shown, respectively. The die is a flat plate having an upper surface 201 and a through hole extending from the upper end 201 to the lower end. The hole has an upper end diameter dp2 and a lower end diameter dp1 less than dp2. The hole 202 is preferably circular throughout, but in other embodiments the hole may be rectangular or hexagonal over the entire thickness tp, in which case dp1 and dp2 are holes (rather than diameter). The length or size to cross. The plate 200 also has a height tp. The taper angle is related to dp2 and dp1 by the formula tanФ = (1/2 (dp2-dp1) / tp), and in a preferred embodiment φ is 1-5 degrees, 5-10 degrees, 3-5 or 2-. It is 4 degrees. The shape of the die 200 produces a conical trapezoidal shank, as shown in FIG. 18A. The beads are placed at the top of the opening 202 so that the raw material beads (not shown) are partially located within the hole 202. A plate, mandrel or pin (“ram head”) is then pushed into the top of the bead so that the bead is pushed into the hole 202. The beads are pushed into the holes until the ram head is at a distance of about HH from the surface 201. The rivet 127 formed from the above-mentioned forming step has a taper angle Ф over the entire or substantially portion of the shank height SH, and the shank shape is conical trapezoidal. The height of the entire rivet is HR, the head thickness is HH, and the head diameter is HD. In some embodiments, the angle Ф may be small enough so that the shank is treated as a cylinder or Ф is near zero.

[0151] With reference to FIGS. 12 and 13A, a second embodiment of the present disclosure with a die 205 and a marker 137 formed using the die 205 is shown, respectively. The die is a flat plate having an upper surface 206 and a hole extending from the upper end 301 to the lower end. The holes have a constant diameter dcb1 throughout. A counterbore is formed at the upper end 206. The counterbore diameter is dcb2. The hole 207 is preferably circular throughout, but in other embodiments the hole 207 may be rectangular or hexagonal, in which case dbb1 is of length or size across the hole (rather than diameter). be. The shape of the die 205 produces a rivet with a stepped cylindrical shape or a cylindrical shank with a head, as shown in FIG. 13A. The beads are placed at the top of the opening 207 so that the raw material beads (not shown) are partially located within the hole 207. The ram head is then pushed into the top of the bead so that the bead is pushed into the hole 207. The beads are pushed into the holes until the ram head is at a distance of about HH from the surface 206. The rivet 137 formed from the above-mentioned forming step takes the shape shown in FIG. 13A. The height of the entire rivet is SH + HH, the head thickness is HH, the shank height is SH, and the head diameter is HD.

[0152] Tables 3 and 4 below provide examples of rivet dimensions for fixing in the link hole 22 as shown in FIG. 2A. In this example, the link thickness is 100 microns (μm) and the values in microns (μm) for D0, D1 and D2 are 241, 64 and 64, respectively.

[0153] The values of the dimensions tp, dp2 and dp1 of the die 200 are 178, 229 and 183. The dimensions of the formed rivets obtained using the die 200 are shown in Table 3. As can be seen from the results, the shank length (or height) is greater than 150% of the link thickness and the rivet head diameter (HD) is significantly larger than the hole 22 diameter. The lower part of the shank is used to form the tip of the rivet. The mean and standard deviations for HD, SD, and SL are based on the rivets of the measured "n" samples, respectively.

[0154] The values of dimension dcb2 and dimension dcb1 of the die 205 are 305 and 203. The dimensions of the formed rivets obtained using the die 300 are shown in Table 4. The mean and standard deviation of HD, SD, HH and SL are based on the rivets of each measured "n" sample.

[0155] In Tables 3 and 4, the "OD rivet head diameter after implantation" refers to the outer diameter of the rivet marker head after the rivet marker is pushed into the scaffold hole.

[0156] Next, an example of a process for attaching either the rivet 127 or 137 to the scaffold hole 22 will be considered. According to some embodiments, the rivet shank is placed in the hole 22 from the antiluminal side or outside of the scaffold so that the head is located on the antiluminal side surface 22a. The rivets may instead be placed from the luminal side of the hole. The rivet is firmly pushed into the hole so that the largest portion of the shank extends from the luminal side or the anti-luminal side, respectively.

[0157] The rivet 127 is placed in the hole 22 and then the opposite side of the head is subjected to the embedding step. Referring to FIG. 11B, a cross section of the deformed rivet 127'in the hole 22 is shown. The rivet 127'has a head 127a' that extends from the surface 22a by an amount h2. The length h2 may be about 25 microns (μm), 25-50 microns (μm), or 5-50 microns (μm). The same dimensions apply to the tip 127b'extending from the opposite surface of the link (eg, the side of the lumen). The diameter of the head portion 127a'may be larger than that of the tip portion, and the diameter of the tip portion 127b' may be larger than the diameter of the head portion 127a'. The tip portion is formed from an extended shank length that protrudes from the link surface by implantation. The tip portion 127b'is formed by embedding. For example, the rivet 127 is arranged from the surface 22a (anti-luminal side) such that a significant portion of the shank length, eg, 50% of the strut thickness, extends from the luminal side. A cylindrical mandrel (not shown) is placed through the lumen of the scaffold. This mandrel has an outer diameter slightly smaller than the inner diameter of the scaffold and provides an embedded surface forming the tip 127b'. The mandrel is rolled back and forth over a shank that extends from the side of the lumen. This action flattens the shank material around the hole, creating a tip portion 127b'. The obtained rivet 127', at least in part, will push the rivet toward the luminal side of the hole 22 and the resistance of the tip portion 127b' that tries to push the rivet toward the anti-luminal side of the hole. It is fixed in a predetermined position by the resistance force of the head portion 127a'. As shown, the deformation of the shank produces a tip portion 127b'with a flange disposed on the surface 22b. The flange may be circular, such as the head, and may have a flange radial length that is greater than or smaller than the radial length of the flange of the head 127a'.

[0158] With reference to FIGS. 15A and 15B, a stepped mandrel is used with the ram head to generate rivets 137'from rivets 137. The rivet has, for example, a shank 137'reformed from the substantially cylindrical shape when using the die 205 of FIG. 12 to the shape shown in FIGS. 15A-15C. This shank shape can be characterized by a taper angle θ as large as about 5-15 degrees, 5-9 degrees, or about 3-8 degrees. The shank according to some embodiments of the rivet of the hole 22 is truncated cone-shaped, with the shank end opposite or distal to the head 137a', i.e. the end 137b', proximal or head of the head 137a'. It has a larger or larger diameter than the shank portion closest to the portion 137a'. The deformed shank 22'has a shank diameter S2 closest to one of the luminal or anti-luminal openings of the hole 22'that is larger than the shank diameter S1 closest to the other of the luminal or anti-luminal openings. It may have, that is, S2> S1. According to some embodiments, as shown in FIG. 15A, the cylindrical hole 22 is also transformed into a hole 22'with an opening on the surface 22b that is larger than the hole opening on the surface 22a. According to some embodiments, the holes 22 and the rivets 137 are deformed when the rivets 137 are attached to the scaffold.

[0159] The structure shown in FIG. 15A can be made by a second step of attaching a rivet marker to the scaffold hole 22. In contrast to the first step, the tool is not rolled over the entire surface where the shank tip protrudes from the hole opening. Instead, the shank tip is pushed directly into a non-compliant surface that can be the surface of a metal mandrel. The rivet is deformed by the compressive force between the surface of the mandrel and the head of the ram 234 that pushes the rivet into the surface of the mandrel. The first step of producing the deformed rivet 127', in contrast, is formed by a combination of rolling a hard surface into the shank and restraint on the head 127a, thereby embedding the tip 127b. The rivet head is held against the surface 22a during the process. Under the second step, the line of action of force is entirely along the axis of the rivet or perpendicular to the rivet head. As a result, the shank portion is smoothed or widened and the hole is deformed, with little or no flange or periphery formed from the tip of the shank.

[0160] Next, the second step will be described in more detail with reference to FIGS. 14A to 14C. The scaffold 400 is placed on the stepped mandrel 230. This mandrel has a first outer diameter and a second outer diameter that is smaller than the first outer diameter. The scaffold portion holding the marker 137 is placed on top of the small diameter portion of the mandrel 230. The large diameter portion of the mandrel 230 holds the adjacent portion of the scaffold. The small diameter portion of the mandrel 230 has a surface 230a and the large diameter portion has a surface 230b. As shown in FIGS. 14B and 14C, the ram 234 pushes the scaffold portion 230a holding the marker 137 into the mandrel surface 230a with a force F (FIG. 14B), whereby the scaffold end is distanced toward the surface 230a. It is deflected by "d" (Fig. 14A). After the scaffold reaches the surface 230a, the ram 234 pushes in the scaffold portion that continues to hold the marker (by directly pressing the head 137a) and deforms the marker 137'and the hole as shown in FIG. 15A. Generate 22'. The surface 230a selected is smooth or free of grooves, pitting, dents and other surface irregularities (other than the surface of the cylinder) that would impede the flow of material during implantation. May be good. In a preferred embodiment, the mandrel surface is smooth compared to the surface of the head 234 pushed into the rivet marker 137. That is, the coefficient of friction (Mu) between the head 234 and the surface 137a'is greater than the Mu between the surface 230a and the surface 137b' of the mandrel 230.

[0161] The deformed shank 137'and hole 22'shapes shown in FIG. 15B produced a greater push force than previously thought (“push force” is required to remove the marker from the hole. Means power). In fact, unexpectedly, the deformed rivets 137'and holes 22'have greater resistance to shedding than markers fitted to links with 50% thicker thickness, with or without head 137a'. Was discovered. For example, a test of the minimum dropping force required to extrude a rivet 137'from the side surface 22a of a 100 micron (μm) thick strut hole 22' is described in U.S. Patent Application No. 2007/01562330 (FIG. 8A, FIG. 8B, or strut holes with a thickness about 50% larger (158 microns (μm) vs. 100 microns (when the spheres are more cylindrically deformed during storage to maximize surface-to-face contact)). It was higher than the drop-off force required to push out the attached marker for μm)). It is as shown in Table 4.

[0162] Although the scaffold A has more surface area due to contact with the marker and thus has a greater frictional force to resist shedding, the scaffold B has a greater extrusion force. This result shows that the deformation caused by the embedding process resulting in the deformed rivet marker and holes in FIG. 15A has a significant effect on the extrusion force (Note: Kilogram-force reported in Table 4). The pushing force was applied to the lumen side 22b of the scaffold B). Given the 50% greater wall thickness, scaffold A should have had greater shedding power (same bead material, bead volume and poly (L-lactide) scaffold for scaffold A and scaffold B). material). The greater shedding force can be explained by the deformed shank and hole shapes that essentially produce the lower portion 137b'that is significantly larger than the opening 22a of the strut 22. Thus, the drop force is to drop the marker from the 22a side of the hole 22'(not only essentially overcomes the frictional force between the material and the wall of the hole), so that the opening 22a'and / Or it must be large enough to deform the shank portion 137b'.

[0163] The shape 137'of FIG. 15B can be formed by an embedding step that deforms the rivet while the rivet is located inside the hole 22. The rivet may have the shape and / or characteristics of the rivet 27, rivet 127 or rivet 137 prior to implantation. The lateral flow of the rivet material during implantation near the tip portion 137b'(shear flow) causes the rivet material to expand and the strut holes to approach (expand) the opening 22b'. This forms a trapezoidal or conical trapezoidal shape of the rivet shank and hole. In the embedding step of FIGS. 14A-14C, an equal opposite force is applied on approximately the same straight line as the rivet's axis of symmetry (rather than rolling motion on one side). Instead (rather than rivets) a cylinder or sphere is placed in the hole 22 and between the mounting surface 230a and the tip 137b, approximately the coefficient of friction (COF) between the mounting surface 234 and the head 137a. If the same COF was present, but otherwise the same embedding process as in FIGS. 14A-14C, the result would be more symmetric, such as the shape shown in US Patent Application No. 2007/01562330. It is considered that the marker became a deformed marker, for example, a cylindrical or barrel-shaped marker crushed according to the COF. The results are described in Kajtoch, J Strine in the Upsetting Process, Metallurgy and Foundry Engineering, Vol. 33, 2007, No. It can be understood by reading 1 (discussing the effect of the coefficient of friction between the ram and the ingot on the resulting shape for slenderness ratios greater than 2). The shape of the radiodensity material pushed into the hole, such as rivet 137 pairs (scaffold A), is also a factor. The presence of the head on one side causes the shank to form an asymmetrical shape around the strut center plane axis. It is considered that the combination of the rivet shape and the difference in the coefficient of friction produced favorable results.

[0164] In a preferred embodiment, the smooth mandrel 230 surface 230a presses the surface 137b as compared to the rougher surface of the head 234 that presses the surface 137a. In a preferred embodiment, the coefficient of friction on the antiluminal side was greater than 0.17, i.e. Mu> 0.17, whereas the coefficient of friction on the luminal side was less than 0.17, i.e. Mu <0.17. rice field. As mentioned above, the effect of the difference in coefficient of friction can be explained by the shear flow near the end in contact with each embedding head or the constraint on the subsequent material flow. If the coefficient of friction is low enough, the surface area will expand laterally rather than remain relatively constant. Therefore, since Mu is small on the luminal side, there is more lateral flow than on the anti-luminal side. The result, when combined with the use of the rivet shape, is believed to be the disclosed truncated cone shape, as shown in FIGS. 15A-15B, which could be considered, for example, a shank with a fixed angle θ.

[0165] There may be a heating step for scaffolding after marker placement. In some embodiments, this heating step may correspond to a pre-crimp scaffold polymer recovery step that eliminates the aging effect of the polymer.

[0166] Pre-crimp thermal recovery (including heat treatment of bioabsorbable scaffolds above TG but below the melting temperature (Tm) of the polymer scaffolds) reverses the physical aging of the polymer scaffolds or It can be removed and can reduce the number of crimp damage and / or marker dropouts (eg, in scaffold piles).

[0167] According to some embodiments, the scaffold is heat treated, mechanically distorted, or solvent treated to recover polymer aging or immediately prior to crimping the scaffold into the balloon and after placement of the marker. Induce erasure. Recovery eliminates or reverses the changes in physical characteristics caused by physical aging by returning the polymer to a less aging or even pre-aging state. Physical aging brings the polymer closer to thermodynamic equilibrium, and recovery moves the material away from thermodynamic equilibrium. Therefore, recovery can change the properties of the polymer in the opposite direction to that caused by physical aging. For example, recovery can reduce the density of the polymer (increase the specific volume), increase the break point elongation of the polymer, reduce the modulus of the polymer, increase the enthalpy, or give rise to any combination thereof. ..

[0168] According to some embodiments, recovery is desirable for reversal or elimination of physical aging of the previously treated polymer. However, recovery is not intended to remove, invert, or erase the memory of the previous processing step. Therefore, recovery does not train the scaffold or tube, nor does it give memory to the scaffold or tube. Memory can refer to the transient polymer chain structure and transient polymer properties provided by the previous processing step. This includes a process step of radially strengthening the tube for forming a scaffold by inducing biaxial stretching of the polymer chain into the tube described herein.

[0169] With respect to the integrity or resistance to shedding of the Marcus scaffold during crimping, heating steps have been found to help reduce the cases of crimping causing marker shedding. According to some embodiments, any of the aforementioned embodiments of the marker held in the scaffold hole 22 is a heating step immediately before the crimp, eg, within 24 hours after the crimp, after the marker is placed in the hole. Can be included. It has been found that the scaffold can better hold the marker in the hole 22 after heating. Mechanical strain, such as limited radial expansion, or thermal recovery (which raises the scaffold temperature above the glass transition temperature (TG) of the load-bearing portion of the scaffold polymer for a short period of time) is post-crimp. And / or may have a beneficial effect on the structural integrity of the scaffold after balloon expansion from the crimped state.

[0170] In particular, these strain-inducing steps tend to have a beneficial effect on the hole 22 dimensions surrounding the marker when the hole is deformed as described above in relation to FIGS. 15A-15B.

[0171] According to some embodiments, the scaffold after marker placement is heated over 10-20 minutes to a temperature about 20 or 30 degrees above the glass transition temperature of the polymer. More preferably, the scaffold's load-bearing structure (eg, a portion made from a polymer tube or material sheet) is a polymer containing poly (L-lactide), the temperature of which is about 10-20 minutes after marker placement. Raise to 80-85 ° C.

[0172] According to some embodiments, it has been found that increasing the temperature of the scaffold after placement of the marker reshapes the portion of the hole 22 to improve the fit of the marker into the hole. ing. Referring to FIG. 15C, after the rivet marker 137 is placed in the hole 22 according to the second step, the hole shape is deformed to generate a lip or edge 140 at the end 137b', which is processed in the recovery step. A greater resistance to dropout than the non-scaffold marker structure can be generated. The surface 140a of the lip 140 more strongly prevents the marker from falling off when the force is directed towards the end 22b'.

[0173] According to the aforementioned objectives of achieving the desired crimp profile of thin-walled scaffolds, there is a method for crimping such scaffolds into a balloon that meets the following requirements:
Structural integrity: Avoiding damage to the scaffold's structural integrity when the scaffold is crimped into or expanded by the balloon.
Safe introduction to the site of transplantation: To avoid dropping or separating the scaffold from the balloon during transfer to the site of transplantation.
Uniformity of expansion: Avoiding non-uniform expansion of the scaffold ring, which can lead to structural damage and reduced fatigue life.

[0174] As previously reported in US Patent Application No. 2014/096357, scaffolds are not as elastic as highly ductile metal stents. Therefore, the need to meet all of the above needs is specifically for thin scaffolds that can be more easily damaged during crimping or balloon dilation.

[0175] FIGS. 17A-17B show the steps associated with the crimping step for crimping into a balloon catheter (FIG. 3D) for thin-walled scaffolds 300, 400, 500, 600 or 700 according to the present disclosure. It has been found that this crimping step can meet all of the above requirements for scaffolds crimped down to D-min. In this example, a crimping step for crimping a 3.5 mm scaffold into a 3.0 mm semi-compliant PEBAX balloon is described. In FIG. 17B, the flow of the crimped portion of the flow of FIG. 17A in graph form, i.e., a balloon pressure of about 20-70 psi (or 1 atmosphere to fully inflated or overinflated balloon pressure) is applied over almost the entire crimping process. A graph of scaffold diameter vs. time is shown. For example, the balloon pressure is maintained at 70 psi in steps A through G and then reduced (or contracted) to 50 psi (or 1 atm) over periods GH. Balloon pressure is removed at point H. In steps H through J, no balloon pressure is used for the purpose of achieving a low transverse profile or crimping to D-min and avoiding balloon damage.

[0176] FIG. 17A shows three possible methods of crimping, as needed. First, two balloons, balloon A and balloon B, are used. Balloon B is used for the pre-crimp step (s) and Balloon A (used with the introduction system) is used for the final crimp. Second, only one balloon is used throughout the crimping process, including the alignment confirmation test (balloon A). In this case, the scaffold inner diameter is larger than the fully inflated or overinflated balloon A. Therefore, a shift may occur on the balloon before crimping. Third, only one balloon is used throughout the crimping process without final alignment confirmation inspection (balloon A). In this case, the balloon for the introduction system has a fully inflated or overinflated state approximately equal to the inner diameter of the scaffold inner diameter.

[0177] Stage I: A scaffold supported on a fully inflated balloon of a balloon catheter is placed within the crimp head. When inflated and supporting the scaffold in this state, the balloon has virtually all creases removed. In a preferred embodiment, the catheter balloon (ie, the final product, the balloon used in the stent introduction system) is used for stage I-stage II. In other embodiments, it may be preferable to use a second larger balloon for stage I and stage II (as detailed below). The crimp blade is heated to raise the scaffold temperature to the crimp temperature. In a preferred embodiment, the crimp temperature is between the lower limit of the polymer's glass transition temperature (TG) and 15 degrees between TGs.

[0178] After the scaffold reaches the crimp temperature, the crimp iris closes, reducing the scaffold inner diameter (ID) to a diameter slightly smaller than the outer diameter (OD) of the fully inflated or overinflated balloon. (For example, from 3.45 mm to about 3.05 mm for a PEBAX 3.0 mm semi-compliant balloon inflated to a diameter of about 3.2 mm). In this example, balloon B should be used to reduce the diameter to 3.0 mm balloon size, or balloon A size (eg, 3.0 mm balloon).

[0179] Stage II: The crimp jaw is held at a diameter of 3.05 mm and maintained at this diameter at crimp temperature for a second rest period. After Stage II, the scaffold has about 90% of its pre-crimp diameter.

[0180] In steps I-II described above, the scaffold diameter is reduced to the size of the fully inflatable balloon (ie, balloon A) of the stent introduction system. At the time of the first alignment test (before crimping), the scaffold inner diameter was larger than the balloon's full inflatable diameter (eg, the scaffold diameter was about the full inflatable diameter of the balloon with a diameter of 3.0 mm to 3.2 mm). (109% -116%), so there is a possibility of longitudinal displacement (relative to the balloon) while the scaffold is crimped to balloon size. With this possibility in mind, the scaffold is removed from the crim and the alignment of the scaffold on the balloon with respect to the proximal and distal balloon markers is examined.

[0181] "Final Alignment Confirmation" step: When the scaffold needs to be adjusted on the balloon, the technician makes a manual adjustment to move the scaffold into place. However, these tweaks have proven difficult to make while the scaffold is mounted on a fully inflated balloon and has an inner diameter slightly smaller than the outer diameter of the balloon. To address this need, the balloon pressure is slightly reduced or the balloon is temporarily contracted to facilitate realignment. When the scaffold is properly realigned between the balloon markers, the scaffold and fully inflated balloon are returned to the crimper. Now that the scaffold inner diameter and balloon size are approximately equal, the final crimp of the scaffold into the balloon of the catheter can be initiated. It is preferred that the scaffold diameter be slightly smaller than the balloon's fully inflated diameter prior to the start of stage III to prevent the scaffold from moving further longitudinally with respect to the balloon. As mentioned above, when using two balloons, the balloon B is replaced with the balloon A, the balloon A is aligned, and the scaffold is crimped to the final diameter of the balloon B.

[0182] Stage III: Return the scaffold and balloon to the crimper. The jaw closes to a diameter approximately equal to or slightly larger than Stage II (taking into account the recoil that occurs during the alignment test). The crimp's jaw is held at this diameter for a third rest period, which time may be the time required for the scaffold to return to the crimp temperature.

[0183] The iris diameter is then reduced to an ID that is approximately equal to or slightly smaller than the OD of the balloon if the balloon was not pressurized and had randomly distributed creases. That is, the scaffold is crimped to the approximate OD of the balloon when the balloon is pressurized and then contracted so that almost all ready-made creases are replaced by random creases. For example, the iris diameter is reduced to about 1.78 mm for a 3.5 mm scaffold. After this diameter reduction, the scaffold OD is about 60% of its diameter at stage III and about 50% of its starting OD or pre-crimp OD.

[0184] Stage IV: After reducing the scaffold OD to about 50% of its starting diameter, the crimson jaw is retained at this diameter for a third rest period. In a preferred embodiment, the balloon pressure is slightly reduced during this rest. For example, with a 3.0 mm semi-compliant PEBAX balloon, the pressure drops from 70 psi to 50 psi during stage IV dormancy. This reduction is preferred to achieve a lower transverse profile and / or protect the balloon material from hyperstretching.

[0185] After the rest period of step IV, the balloon is deflated or returned to atmospheric pressure to reduce the crimp iris to about 30% of the final crimp OD, eg 1.01 mm or its pre-crimp OD. This balloon contraction can be performed by opening a valve that supplies pressurized gas to the balloon while, or shortly before, the iris diameter is reduced to the final crimp diameter.

[0186] The crimp's jaw is then rested for approximately 170 seconds, either maintaining the crimp temperature (ie, the scaffold temperature is below TG between 15 degrees and approximately TG) or without maintaining the crimp temperature. Hold at final crimp diameter for a period of time, or 100-200 seconds. This final rest period is intended to reduce the amount of scaffold recoil when the crimped scaffold is removed from the crimp. Immediately after a 170 second rest, the scaffold is removed and the scaffold is covered with a retaining sheath to further reduce recoil. A leak test may be performed after the final stage of crimping.

[0187] It may be necessary to provide an auxiliary pressure source for the balloon in order to maintain a relatively constant pressure throughout the diameter reduction and rest period (as shown in the example above). In fact, in one embodiment, it was found that a pressure drop occurred in the balloon during diameter reduction. To cope with this pressure drop, a secondary pressure source was used to maintain the same pressure during the diametrical reduction as during the rest period.

[0188] The aforementioned example of the preferred crimping step of selectively pressurizing the balloon throughout the crimp step is expected to minimize possible hyperextension of the balloon while at the same time providing three benefits. The first advantage is increased scaffold balloon retention. By maintaining a relatively high pressure on the balloon through most of the crimp steps, the balloon material scatters more than if the crimp is performed without balloon pressurization or only after the diameter of the scaffold has been substantially reduced. More balloon material should be placed between the struts of the scaffold as it will be pushed more into the fold. In addition, it is also expected that the balloon material will be more compliant by substantially removing the creases prior to diameter reduction. Thus, more balloon material can extend between the struts rather than being pushed between the scaffold and the catheter shaft when the scaffold is crimped.

[0189] The second advantage of balloon pressurization is the more uniform expansion of the crimped scaffold as the balloon is expanded. If the balloon is inflated from the beginning, before crimping, if there is maximum space available for the balloon to unfold within the attached scaffold, the balloon material will be more perimeter of the catheter shaft after crimping. It is evenly arranged. In a preferred embodiment, the balloon is fully inflated and held in this inflated state for at least 10 seconds prior to crimping to ensure that all ready-made creases are removed. The balloon is only partially inflated and creases, such as when the balloon is inflated after the scaffold is partially crimped (hence, there is not much space left for the balloon to fully unfold). If the line or balloon memory is not removed by balloon pressure, the presence of creases or partial creases causes displacement or displacement of the balloon material during crimping, thereby distributing the balloon material around the catheter shaft after crimping. Is thought to be more non-uniform.

[0190] A third advantage is the avoidance of out-of-plane twisting or scaffold strut overlap that can result in strut strength loss, cracking or breakage. As mentioned above, supporting the scaffold in the crimper with an inflated balloon may reduce or minimize the tendency of the struts to deviate from the alignment.

[0191] The aforementioned advantages can be achieved without the risk of excessive stretching of the balloon material in the crimping process where the balloon pressure is selectively controlled. Referring to FIG. 3B, the pressure range provided is 20-70 psi. The upper limit of this pressure range can form a fully inflatable balloon in the case of the balloon used in the example and be maintained over the first three stages. Subsequently, at stage IV, the balloon pressure is reduced to 50 psi and 20 psi. Several tests have shown that constant, consistent, fully inflated balloon pressure until the onset of Stage IV, or after the crimped scaffold reaches about 1/2 of the original scaffold diameter, followed by a slight decrease in pressure. It was found that maintaining a good balance of stent retention, uniform expansion, low transverse profile, uniform crimp and damage avoidance to the balloon material.

[0192] As mentioned above, there are three possible ways to crimp. Two balloons, balloon A and balloon B, are used. Balloon B is used in the pre-crimp step (a) and Balloon A (used with the introduction system) is used for the final crimp. Second, only one balloon is used throughout the crimping process, including the alignment confirmation test (balloon A). In this case, the scaffold inner diameter is larger than the fully inflated or overinflated balloon A. Therefore, a shift may occur on the balloon before crimping. Third, only one balloon is used throughout the crimping process without final alignment confirmation inspection (balloon A). In this case, the balloon for the introduction system has a fully inflated or overinflated state approximately equal to the inner diameter of the scaffold inner diameter. These different embodiments will be further described below.

[0193] In some embodiments, the steps are described as described above by the examples of FIGS. 17A-17B, with the following exceptions: Use two balloons. That is, not only the balloon A as in the above example of the preferred embodiment, but also the sacrificial balloon or the secondary balloon (balloon B) is used in addition to the balloon of the catheter (balloon A). Balloon B is a balloon that has a nominal inflatable balloon diameter larger than balloon A or can be overinflated to a diameter larger than balloon A. Balloon B is used for stage I and stage II. Balloon B is selected to have a full expansion diameter that is the same as or slightly larger than the original inner diameter of the scaffold. One advantage of this alternative embodiment is that the scaffold is a crimping step (as opposed to the example above, where balloon A provides little or no radial support for the scaffold due to the gap at stage I). Is to be supported by a balloon through. After stage II, the scaffold is removed from the crim and balloon B is replaced with balloon A. After that, the crimping process is continued as described above.

[0194] The above description of the illustrated embodiments of the invention is exhaustive, including those described in the abstract, and is intended to limit the invention to the disclosed embodiments. is not. Specific embodiments of the invention and examples thereof are described herein for illustration purposes, but as will be appreciated by those skilled in the art, various modifications are possible within the scope of the invention.

[0195] These modifications can be made in the light of the above detailed description of the present invention. The terms used in the claims should not be construed as limiting the invention to the particular embodiments disclosed herein.

Claims (13)

A thin-walled scaffold with a network of multiple rings interconnected by links, each ring having multiple peaks, each of which is one of the U-top, Y-top and W-top. With the thin scaffold, the ring extends circumferentially along a vertical axis (BB) perpendicular to the longitudinal axis (AA).
A marker link extending between the first ring and the second ring of the plurality of rings, wherein the marker link includes a structure having a hole, and a radiation opaque material is contained in the hole. A medical device comprising the marker link, which comprises the above.
The marker link forms the W apex of the first ring and the first ring, and forms the Y apex of the second ring and the second ring, from the W apex of the first ring. The first half wavelength of the first ring extending to the adjacent U top in the first ring extends from the Y top of the second ring to the adjacent U top in the second ring. Greater than 1/2 wavelength of ring 2
The marker link includes a first link portion extending from the structure to the W top of the first ring and a second link portion extending from the Y top of the second ring to the structure. , A medical device in which the width of the first link portion is larger than the width of the second link portion. The medical device according to claim 1, wherein the length of the marker link is larger than the length of the link connecting the second ring to the third ring coupled to the second ring. The medical device according to claim 2, wherein the length of the first link portion is smaller than the length of the second link portion. The structure includes a first hole and a second hole each containing the radiation opaque material, and the first hole and the second hole are parallel to the axis ( AA ) . The medical device according to any one of claims 1 to 3, which is arranged in. The first ring includes a first mountain, a second mountain and a third mountain, the first mountain corresponds to the W top of the first ring, and the second mountain is. Next to the first mountain, the third mountain is next to the second mountain, and the second wavelength extending from the second mountain to the third mountain is from the first mountain. The medical device according to claim 1, which is smaller than the first wavelength extending to the second mountain. The length of the flat surface portion of the W top of the first ring is the flat surface portion of the W top of the third ring of the third ring coupled to the second ring, and / or said . The medical device according to claim 1, wherein the length of the flat surface portion of the W top of the first ring formed by the link other than the marker link and the first ring is larger than the length of the flat surface portion. The first aspect of the present invention, wherein the wavelength of the first ring forming the W apex of the first ring is larger than the wavelength of the second ring forming the Y apex of the second ring. Medical equipment. A thin-walled scaffold with proximal and distal ends formed by a network of multiple rings interconnected by links, each ring having multiple peaks, where the peaks are U-tops. , Y-top and W-top, each ring extending circumferentially along a vertical axis (BB) perpendicular to the longitudinal axis (AA). With the thin-walled scaffold,
A marker link extending between the first ring and the second ring of the plurality of rings, wherein the marker link includes a structure having a hole, and a radiation opaque material is contained in the hole. A medical device comprising the marker link, which comprises the above.
The marker link forms the W apex of the first ring and the first ring, forms the Y apex of the second ring and the second ring, and the W apex of the first ring. Corresponds to the first mountain,
The first wavelength of the first ring measured from the first mountain to the second mountain next to the first mountain in the first ring is from the second mountain to the second mountain. Greater than the second wavelength of the first ring measured up to the third ridge next to it in one ring,
A medical device having an aspect ratio (AR) of the marker link of 4-5 or about 4.5, wherein AR is defined as the maximum width of the marker link divided by the wall thickness of the marker link. The first ring has n peaks and n wavelengths, n is at least 6 and is 12 or less, and the first wavelength and the second wavelength are from the first peak. The medical device according to claim 8, wherein the first crest is larger than any of the remaining ( n-2 ) wavelengths of the first ring, respectively, measured up and down. The medical device according to claim 9, wherein the remaining ( n-2 ) wavelengths all have the same length. The medical device according to any one of claims 8 to 10, wherein the length of the marker link is substantially equal to the length of the link connecting the second ring to the third ring. A thin-walled scaffold with proximal and distal ends formed by a network of rings interconnected by links, where each ring is of the U-top and the Y-top and W-top. It has multiple tops, including at least one of, and each ring extends circumferentially along a vertical axis (BB) perpendicular to the longitudinal axis (AA). A medical device equipped with the thin-walled scaffold.
The proximal end portion comprises the outermost proximal ring coupled to the first proximal ring by a first proximal link, the first proximal ring being second by a second proximal link. It is attached to the proximal ring of
The distal end portion comprises the outermost distal ring coupled to the first distal ring by a first distal link, the first distal ring being second by a second distal link. It is attached to the distal ring of
(1) The first proximal link comprises a proximal marker link with a pair of proximal holes containing a radiation opaque material, the proximal hole being arranged along the axis ( AA ) . Has been
(2) The first distal link comprises a distal marker link with a pair of distal holes containing a radiopaque material, the distal hole being placed along the axis ( BB ) . It is a medical device. A thin-walled scaffold with proximal and distal ends formed by a network of rings interconnected by links, where each ring is of the U-top and the Y-top and W-top. It has multiple tops, including at least one of, and each ring extends circumferentially along a vertical axis (BB) perpendicular to the longitudinal axis (AA). A medical device equipped with the thin-walled scaffold.
The proximal end portion comprises the outermost proximal ring coupled to the first proximal ring by a first proximal link, the first proximal ring being second by a second proximal link. It is attached to the proximal ring of
The distal end portion comprises the outermost distal ring coupled to the first distal ring by a first distal link, the first distal ring being second by a second distal link. It is attached to the distal ring of
(1) The first proximal link comprises a proximal marker link comprising a proximal hole containing a radiation opaque material.
(2) The first distal link is non-linear and lacks the link that holds the radiodensity material.
Medical equipment.

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