Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/82—Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/86—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure
  • A61F2/90—Stents in a form characterised by the wire-like elements; Stents in the form characterised by a net-like or mesh-like structure characterised by a net-like or mesh-like structure
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2230/00—Geometry of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
  • A61F2230/0002—Two-dimensional shapes, e.g. cross-sections
  • A61F2230/0028—Shapes in the form of latin or greek characters
  • A61F2230/0054—V-shaped
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2240/00—Manufacturing or designing of prostheses classified in groups A61F2/00 - A61F2/26 or A61F2/82 or A61F9/00 or A61F11/00 or subgroups thereof
  • A61F2240/001—Designing or manufacturing processes

Definitions

• Vascular prostheses such as stents and/or stent-grafts are used for a variety of reasons in the vasculature. For example, they can be used to prop open blood vessels, treat plaque buildup, replace a portion of a blood vessel, divert blood flow away from a target area, provide a scaffold or lumen for the introduction of other medical devices, or for various other reasons.
• Stents, stent-grafts, or other vascular prostheses are sometimes formed of one or more wires that are braided into a tubular structure.
• the wire can be braided so as to terminate along the length of the stent instead of at the stent's proximal or distal ends.
• the hand-braided stent's ends may be relatively smooth.
• a stent is machine-braided, its wires must typically be cut at its distal and proximal ends, creating relatively rough/sharp stent ends. Whether hand-braided or machine-braided, sharp stent ends can cause damage to the vessels as it is deployed and therefore is undesirable.
• One aspect of the present invention is directed to techniques and embodiments that reduce or eliminate any relatively sharp or rough edges created from wire ends of a braided stent.
• the wire ends of a stent can be terminated in an end cap or by bending and welding the stent's wires.
• a device in particular a vascular prosthesis, in particular a stent and/or stent-graft is described.
• the device is comprised of one or more layers.
• the device is comprised of metallic wires.
• the device is comprised of two layers - an inner and an outer layer.
• the device is comprised of two layers, where each layer is comprised of metallic wires.
• the device can utilize a tie component to bind the multiple layers together.
• the tie component is comprised of one or more wires.
• the tie component is comprised of one or more radiopaque wires.
• the tie component can be woven in an over-under pattern relative to the multiple layers of the device.
• the device is comprised of an inner and outer layer.
• the outer layer has proximal and distal end loops or flares.
• the flares are comprised of wire pairs which combine to form the flares.
• a flare cap is used to secure the wire pairs.
• some of the flares are short and some of the flares are long.
• the outer layer utilizes proximal and distal short and long flares.
• the tie component generally follows the path of some of the wire(s) which comprise the flares.
• the device is comprised of an inner and outer layer. Both layers are comprised of wires.
• the wires comprising the outer layer have eyelets and pairs of these eyelet-comprising wires mate with each other.
• a method of making a device in particular a stent and/or stent-graft, is described.
• the device is wound over a mandrel with a compressed middle section and an expanded proximal and distal section.
• the expanded proximal and distal sections help create the flares and comprise channels to facilitate passage of the wires comprising the device.
• the wires can be cut at select locations to create the flares, and the wire pairs comprising the flares are bound with flare caps.
• a method of using a device, in particular a prosthesis, in particular a stent and/or stent-graft is described.
• the prosthesis is used to treat atherosclerosis where the prosthesis is used in a blood vessel to keep the blood vessel open to maintain blood flow.
• the prosthesis is used to treat superficial femoral artery disease where the prosthesis is placed within the superficial femoral artery and/or popliteal artery
• Figure 1 illustrates an embodiment of a stent according to the present invention.
• Figures 2-3 illustrate views of an outer layer of the stent from Figure 1 .
• Figures 4-5 illustrate a technique of creating end caps for the wires of the stent from Figure 1.
• Figures 6-9 illustrate various alternate embodiments of blunted wire ends from a stent.
• Figures 10-12 illustrate a mandrel for winding a stent or stent layer.
• Figure 13 illustrates an alternate embodiment of a mandrel end having grooves.
• Stents, stent-grafts, or other vascular prostheses are sometimes formed of one or more wires that are braided into a tubular structure.
• the wire can be braided so as to terminate along the length of the stent instead of at the stent's proximal or distal ends.
• the hand-braided stent's ends may be relatively smooth.
• a stent is machine-braided, its wires must typically be cut at its distal and proximal ends, creating relatively rough/sharp stent ends. Whether hand-braided or machine-braided, sharp stent ends can cause damage to the vessels as it is deployed and therefore is undesirable.
• One aspect of the present invention is directed to techniques and embodiments that reduce or eliminate any relatively sharp or rough edges created from wire ends of a braided stent.
• FIGS 1 -3 illustrate a braided stent 100 having distal and/or proximal ends that are rounded or blunted.
• the braided stent has an outer layer 102 woven from a plurality of wires 104 that terminate with triangular or pointed loops 1 10.
• Each triangular loop 1 10 is preferably formed from two wires 104 that contact each other at their ends and terminate in a single end cap 1 12. These end caps 1 12 allow the ends to move freely without the complications of sharp or rough edges that would otherwise be present.
• end caps 1 12 can also be used as a part of a delivery device to help hold and/or retrieve the stent 100 prior to full deployment where the delivery system grips the caps 1 12 to secure the stent 100 to the delivery system, and allow for greater retractability as described in co-pending U.S. Patent Application No. 15/268,271 , which is incorporated by reference in its entirety.
• Figures 4 and 5 illustrate one technique of creating these triangular loops 1 10 and end caps 1 12.
• the crimp 1 14 can be a tube or a "C" shaped structure and is preferably composed of a material suitable for welding, such as Nitinol.
• the crimp 1 14 may be further crimped or compressed around the two wires 104 after placements to help maintain its position. If the ends of the two wires 104 are not in close proximity to the top of the crimp 1 14, the wires 104 can be trimmed to such a level.
• location 1 16 is welded (e.g., laser welded), melting the ends of the wires 104 and the crimp 1 14 together until a shape resembling a rounded ball or cap results (i.e., end cap 1 12).
• the crimp 1 14 is illustrated as a tube, in an alternate embodiment it can be configured as a cap member (e.g. metallic materials such as Nitinol, or radiopaque materials such as tantalum) having an inner spaced sized for two wires 104 and a closed end.
• a cap member e.g. metallic materials such as Nitinol, or radiopaque materials such as tantalum
• the wires 104 can be trimmed to a desired length, moved together, and the cap can be placed over and welded onto the wires 104.
• the wires can either contact each other at or near the cap location or even be separated entirely - depending on the size of the cap.
• Figure 6 illustrates an alternate technique for creating a stent 100 with blunted or smooth ends, having an end cap 122, but without a crimp 1 14.
• Symmetrical bends at locations 104C are created with the two wires 104. If necessary, the wires 104 are trimmed closely to the bend location 104C and the ends of the wires 104 near the bends 104C are welded (e.g., laser welded) at one or more weld locations 1 16 (e.g., three weld locations) until the wire ends resemble a rounded cap shape.
• Figure 7 illustrates another alternate technique for creating a stent 100 with blunted or smooth ends, creating a curved or bent end 1 18.
• One wire 104A is trimmed to a length that is longer than the wire 104B it is to be joined to (e.g., between 1 mm to 10 mm longer).
• the longer wire 104A is bent at location 104C to an angle that is preferably between, for example, about 90 and about 160 degrees so that the ends of the two wires 104A and 104B overlap when moved in proximity to each other.
• one or more welds are created at locations 1 16 (e.g., three welds).
• Figure 8 illustrates yet another alternate technique for creating a stent 100 with blunted or smooth ends, creating a rounded curve 120.
• a curved or rounded segment 104D is created at the ends of both wires 104 that are to be joined together. These curved segments 104D are moved together and welds are created near the ends of each wire 104 at locations 1 16.
• the weld locations 1 16 can be located between the very end of one wire 104 and a location spaced apart from the end of the other wire 104, creating two or more weld locations 1 16 (e.g., 4 total weld locations 1 16 per rounded curve 120).
• Figure 9 illustrates yet another alternative embodiment for creating a stent 100 with blunted or smooth ends involving the use of eyelets 132.
• the wires 104 comprising the outer layer of the stent 100 would utilize a wire with eyelets 132 on both the proximal and distal ends of the wires 104.
• the eyelets 132 may be formed by pulling the wire 104 back onto itself and welding the wire at location 134.
• the eyelet 132 of one wire end is first created.
• the second wire is then inserted into the eyelet 132 of the first wire end, and the second wire is then welded at location 134 to create the second eyelet 132 to connect the eyelets 132.
• the eyelets 132 allow the wires 104 to be free to move relative to each other around the eyelet region.
• this configuration offers some advantages in terms of flexibility of the stent 100.
• the stent 100 is shown as comprising two layers, an inner layer 106 and an outer layer 104 (although alternative embodiments may only have a single layer). In one embodiment, both layers are comprised of metallic wires or ribbons, such as nitinol wires.
• the inner layer 106 is preferably comprised of 36-60 braided wires (48 wires).
• the diameter of the wire 108 of the inner layer 106 can range from about 0.001 " to about 0.003", such as about 0.0016" to about 0.002".
• the outer layer 102 is also preferably comprised of 6-24 braided or woven wires 104, such as 12 wires.
• the wire 104 of the outer layer 102 preferably has a diameter between about 0.004" to about 0.008", and more preferably between about 0.0055" to about 0.007".
• the wires 104, 108 are preferably comprised of a metallic material such as nitinol, a radiopaque material, can be coated with radiopaque material, or can have a radiopaque core. Other materials such as cobalt-chromium or stainless steel may also be used.
• the outer layer 102 is located axially outward relative to the inner layer 106.
• the inner layer 106 is formed of a braided mesh structure with a tubular shape that is longer than the outer layer 102 and where the mesh of the inner layer 106 is cut at either or both ends.
• the outer layer 102 is comprised of a braided mesh of 12 wires 104 and the terminal ends (i.e. at the proximal and distal ends) of the wires 104 comprising the outer layer terminates into 6 flares or triangular loops 1 10.
• the loops 1 10 may all be about the same length or can vary in length.
• the loops 1 10 may alternate between relatively longer loops 1 10 and relatively shorter loops 1 10, which may improve tracking through a catheter by distributing contact points to various places around the inner periphery of the catheter instead of concentrating the contact points to a few particular sections.
• the areas of high friction are decentralized, which improves pushing through the catheter or delivery device.
• the outer layer 102 may be comprised of 8 wires and 4 triangular loops 1 10 at both ends or may be comprised of 16 wires with 8 triangular loops 1 10.
• the outer layer 102 and inner layer 106 may also be connected via a number of different tie mechanism, such as one or more woven wires or wire coils. Additional details of the tie components, inner/outer layers, and other aspects of the stent 100 can be found in U.S. Pub. No. 20130245745, the contents of which are hereby incorporated herein by reference.
• the tie component is comprised of one or more wire that are weaved under the inner layer and over the outer layer of the prosthesis to bind the layers together.
• the tie component is comprised of a tantalum wire woven through the inner and outer layers of the prosthesis. In one embodiment, the tie component is comprised of a tantalum wire which follows the path of one of the wires which comprise the outer layer.
• a radiopaque material for the tie component such as tantalum, enhances imaging of the device.
• Other radiopaque materials such as palladium, platinum, or gold may also be used.
• Non-radiopaque materials can also be used, for example a nitinol, cobalt-chromium, or stainless steel wire can be used for the tie component.
• the tie component can utilize a radiopaque core with a non-radiopaque cover or a radiopaque cover with a non- radiopaque core.
• Multiple tie components may also be used, where some tie components are radiopaque and some tie components are non-radiopaque.
• the tie component is woven in an over-under pattern with the inner and outer layer of the prosthesis to bind the layers together. The tie component can continue in this over-under pattern through the length of the prosthesis to bind the layers together.
• the tie component is preferentially made of a radiopaque material (i.e. tantalum, or other materials such as platinum, palladium, gold, etc.), the imaging of the device is augmented during delivery and placement of the prosthesis.
• the actual over-under pattern can be customized depending on the properties of the prosthesis.
• a tighter crossing density pattern i.e. one over followed by one under, followed by one over followed by one under, etc.
• a looser crossing density pattern i.e. one under followed by an over pattern over several cells
• Figures 10-13 illustrate tools and techniques for braiding one layer of the stent 100 (e.g., outer layer 102).
• the outer stent layer 102 is wound over mandrel 140, which has a smaller diameter middle region 140B and larger diameter ends 140A.
• the wires 104 are first placed in the longitudinal grooves 144 on one of the larger diameter ends 140.
• two wires 104 are placed into each channel or groove 144 and these wire pairs are later used to later create the triangular loops 1 10.
• the wires 104 are maintained in the grooves 144 by screws 142 that screw into the larger diameter ends 140A and partially overlap on the grooves 144, thereby acting as a clamp mechanism.
• the outer stent layer 102 is braided over the smaller middle diameter 140B. This braiding can be achieved by hand or with braiding machine. Once the braiding is complete, the wires 104 can be clamped with screws 142 in the grooves 144 on the opposite side of the mandrel 140.
• tubing 146 can be placed over each pair of wires 104 to help create the location at which they come together and thereby the size of the resulting triangular loop 1 10.
• the wires can then be connected via any of the previously described techniques in this specification.
• Figures 1 1 and 12 illustrate tubes 146 placed at longitudinally alternating positions which allows for the creation of loops 1 10 that alternate in size (e.g., larger, smaller, larger, smaller, etc.).
• the outer stent layer 102 is then heat set to maintain this braided configuration and size. Further electro-polishing and other manufacturing may be done as well.
• the outer stent layer 102 is then removed from the mandrel 140, the tubing 146 is then removed and the two wires 104 are connected via one of the previously described loop-creation techniques.
• Figure 13 shows an alternative configuration for the larger enlarged ends 104A, different from what is shown in Figures 10-12.
• the grooves 144 are located on a radially tapered face portion of the enlarged end, and the screw 142 (only the recess accommodating the screw is shown, but the screw 142 screws into this recess) is also on the tapered face to lock the wires 104 within the groove 144.
• the inner layer 106 of the stent 100 may also be wound on a mandrel 140 having a substantially consistent diameter throughout, since the inner layer 106 has a substantially consistent diameter.
• the inner layer 106 is then heat set and optionally electro-polished to remove any surface irregularities.
• the inner layer 106 can then be placed within the outer layer and the tie component can be wound through both layers 102, 106 to bind the layers together.
• the heat treatment sets the shape memory to the stent 100.
• the stent 100 is self-expandable and has an expanded shape shape- memory.
• the stent 100 adopts a collapsed configuration during delivery through a delivery device (i.e. a catheter) and radially expands upon release.
• a delivery device i.e. a catheter
• balloons may also be used to open the stent 100.
• the stent 100 described in the various embodiments, in one example, may have an overall size of about 4 millimeters to about 8 millimeters outer diameter, and a length of about 40 millimeters to about 150 millimeters.
• the stent 100 is primarily described as utilizing metallic (i.e. nitinol) wires, however, other materials may be used such as stainless steel, cobalt-chromium, polymers, nitinol, and/or combinations therein may be used. Radiopaque materials such as gold, palladium, tantalum, and/or platinum may also be used, or may be used in combination with the materials described above.
• the stent 100 embodiments described can be stents and/or stent-grafts used for a variety of reasons discussed earlier, such as flow diversion, propping open a vessel, treating a calcified vessel, as a scaffold use to contain additional medical devices, or similar uses.
• the embodiments may also be used in a variety of blood vessels sizes and locations, such as within the smaller vessels of the neuro-vasculature or within the larger vessels of the peripheral vasculature.
• the device can be sized appropriately based on need.
• the stent 100 is used to treat atherosclerotic disease, where blood vessels become calcified and must be propped open.
• the stent 100 helps open the blood vessel and acts as a conduit for blood flow.
• the stent 100 is used to treat superficial femoral artery disease.
• This is a disease state where arthrosclerosis, calcification, and/or plaque occurs in the peripheral vasculature, particularly in the superficial femoral artery and/or popliteal artery near the leg and knee region of the body.
• arthrosclerosis, calcification, and plaque may technically refer to different things, they are being used synonymously here to refer generally to the build-up of unwanted or harmful matter within the blood vessel.
• the stent 100 may be considered a stent-graft since the prosthesis is used to mimic a portion of the vessel which is calcified. Since this artery is located near the knee, the vessels in this area flex considerably and are relatively long.
• a flexible stent-graft is necessary to track the movement of the vessel - however this must be combined with good anchor strength and high radial force so the prosthesis stays at the location and does not migrate.
• the flared ends help anchor the prosthesis in place, the inner and outer layers allow a strong scaffold to prop the blood vessel open, while the potential for a variable tie layer configuration (i.e. the over-under wound pattern described above) can customize the flexibility of the prosthesis.
• a method of use of a device of the preceding embodiments involves placing a balloon in a target region with arthrosclerosis, calcification, and/or plaque and inserting and expanding a balloon in order to compress the calcification toward the vessel wall and break up some of the looser sclerotic buildup.
• the balloon is then deflated and removed.
• the stent 100 is then delivered to the target site and expanded.
• the stent 100 creates a scaffold to constrain the further growth of the sclerotic material, plaque, and/or calcification, and provides a flow-path for blood thus restoring flow to the vessel.
• the device could be used in the superficial femoral artery or the popliteal arteries in the leg.
• the mesh pattern of the inner layer 106 and outer layer 102 offer some advantages when used to treat plaque, calcification, and/or arthrosclerosis.
• the outer layer 102 provides a strong scaffolding layer to contact the buildup, while the smaller mesh size of the inner layer 106 provides relatively small pores which sit radially inward of the outer layer 102.
• These small pore sizes offer a few advantages.
• they limit the amount of plaque that can be serrated or sheared by the stent 100 during placement. While it may be desirable to break up some of the undesirable matter, this is primarily done by the balloon.
• the stent 100 primarily acts as a scaffold to restore blood flow to the region.
• any additional matter which may be sheared off by the inner or outer layer 102, 106 will likely be caught by the small pores of the inner layer 106, and there is therefore less chance of additional fragments shearing off and migrating downstream.
• the small pore sizes of the inner layer 106, sitting under the outer layer 102 provide another scaffolding layer to constrain additional growth of the plaque, sclerotic material, and/or calcification while allowing blood flow through the lumen of the prosthesis.
• the frictional contact points are limited to the outer layer 102 mesh wires 104 and the flared end components, making deliverability easier than a covered textile prosthesis in which the frictional contact is continuous throughout the length of the prosthesis.
• Strong radial force is achieved through the use of the outer metallic mesh layer 102, which may use larger diameter wires than the inner layer 106.
• the end loops 1 10 may offer good anchoring and retention within the vessel, to prevent the stent 100 from migrating after placement.
• the stent 100 also offers some degree of flexibility since the stent 100 is comprised of multiple mesh layers linked together via a tie component. The flexibility of the prosthesis can be customized by controlling the wind technique (e.g.
• the over-under pattern of the tie component.
• a tighter tie component wind pattern would create a stiffer stent 100 where the inner and outer layers 106, 102 have limited freedom to move relative to each other.
• a looser tie component wind pattern would create a more flexible stent 100 where the inner and outer layers 106, 102 have more freedom to move relative to each other.
• the inner layer pore size is between about 200 to about 500 micrometers.
• the outer layer pore size is between about 800 to about 1600 micrometers. The pore size is taken by inscribing a circle within the roughly diamond-shaped cell created by the wires comprising the respective layers.

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• Health & Medical Sciences (AREA)
• Engineering & Computer Science (AREA)
• Biomedical Technology (AREA)
• Cardiology (AREA)
• Oral & Maxillofacial Surgery (AREA)
• Transplantation (AREA)
• Heart & Thoracic Surgery (AREA)
• Vascular Medicine (AREA)
• Life Sciences & Earth Sciences (AREA)
• Animal Behavior & Ethology (AREA)
• General Health & Medical Sciences (AREA)
• Public Health (AREA)
• Veterinary Medicine (AREA)
• Prostheses (AREA)
• Media Introduction/Drainage Providing Device (AREA)

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• 2016
  • 2016-09-16 US US15/268,379 patent/US10335299B2/en active Active
  • 2016-09-16 EP EP16847484.9A patent/EP3349669B1/en active Active
  • 2016-09-16 WO PCT/US2016/052316 patent/WO2017049212A1/en not_active Ceased
  • 2016-09-16 JP JP2018514325A patent/JP6816127B2/ja active Active
• 2019
  • 2019-05-31 US US16/428,677 patent/US11045337B2/en active Active
• 2021
  • 2021-06-01 US US17/336,157 patent/US12329664B2/en active Active
• 2025
  • 2025-05-20 US US19/213,475 patent/US20250339295A1/en active Pending

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