Occlusion device

Abstract

To provide an occlusion device promoting effective endothelial cell proliferation around a device with respect to a field of treatment and / or improvement of Left Atrial Appendage (LAA).SOLUTION: Provided herein is an occlusion device comprising: (a) a substantially solid marker band 40 having an inner and outer diameters, a proximal end 90, and a distal end 100; and (b) a resilient mesh body (20) attached within the marker band, in which the body is a length y, the body comprises a bolus 30 of additional resilient mesh material in length x, y1 is greater than x, the body extends distally from the marker band having a first delivery shape and a second expandable deployed shape. Similarly, provided herein is a kit comprising the occlusion device disclosed herein and means for delivery thereof. A method of manufacture and use of the occlusion device disclosed herein are also disclosed.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present invention generally relates to the field of occlusion devices and / or occlusion device systems and / or implantable occlusion devices and the treatment and / or improvement of the left atrial appendage (LAA).

Background Art

[0002] The left atrial appendage (LAA or left auricle or auricula or left auricle appendix) is a muscular sac or windsock (conical outflow) - shaped structure protruding from the left atrium of the heart. During atrial fibrillation (AF) or mitral valve disease or other cardiac disease conditions, blood clots can form in the LAA. For example, 10 - 20% of patients suffering from AF can exhibit the formation of blood clots in the LAA. Currently, it is known that 90% of the blood clots formed as a result of AF are formed in the LAA. Blackshear JL, Odell JA (February 1996) Ann. Thorac. Surg. 61(2):755 - 9. Such blood clots carry the risk of becoming embolic substances that can come out of the LAA and pose a significant risk related to stroke or other ischemic disorders to body organs. Therefore, LAA occlusion treatment technology is a viable option for the prevention of stroke in AF or other disorders associated with blood clot formation in the LAA.

[0003] LAA occlusion is an alternative treatment strategy to blood coagulants or anticoagulants such as in the class of coumarin - type drugs, heparin - based drugs, small - molecule inhibitor drugs, antithrombin protein - based drugs and / or drugs similar to them. Not all patients are suitable candidates for such blood coagulation drugs due to underlying problems related to past bleeding, non - compliance with medications, and / or pregnancy (in one study, 17% of patients: Gottlieb LK, Salem - Schatz S (September 1994) Arch. Intern. Med. 154(17):1945 - 53), and thus not all patients require other treatment options such as using an occlusion device strategy.

[0004] Current devices for LAA occlusion generally include an expandable nitinol frame or the like. One such catheter-based device includes a body designed to occlude the LAA and a retention member fixed to the body. However, the use of such devices results in fewer hemorrhagic strokes than anticoagulants alone, but has drawbacks and limitations such as, but not limited to, pericardial effusion, LAA closure, device dislodgment, thrombus formation on the device, anatomical mismatch, and / or combinations thereof. Therefore, there is a need for improved occlusion devices in the art.

[0005] Such occlusion devices are described, for example, in U.S. Patent Nos. 5,025,060; 5,496,277; 5,928,260; 6,152,144; 6,168,622; 6,221,086; 6,334,048; 6,419,686; 6,506,204; 6,605,102; 6,589,256; 6,663,068; 6,669,721; 6,780,196; 7,044,134; 7,093,527; 7,128,073; 7,128,736; 7,152,605; 7,410,482; 7,722,641; 7,229,461; 7,410,482; 7,597,704; 7,695,488; 8,034,061; 8,080,032; 8,142,456; 8,261,648; The detailed description; the specification of U.S. Patent No. 8,262,692; the specification of U.S. Patent No. 8,361,138; the specification of U.S. Patent No. 8,430,012; the specification of U.S. Patent No. 8,454,633; the specification of U.S. Patent No. 8,470,013; the specification of U.S. Patent No. 8,500,751; the specification of U.S. Patent No. 8,523,897; and the specification of U.S. Patent No. 8,535,343; and U.S. Patent Application Publication No. 2003 / 0195553; Publication No. 2004 / 0098027; Publication No. 2006 / 0167494; Publication No. 2006 / 0206199; Publication No. 2007 / 0288083; Publication No. 2008 / 0147100; Publication No. 2008 / 0221600; Publication No. 2010 / 0069948; Publication No. 2011 / 0046658; Publication No. 2012 / 0172973; Publication No. 2012 / 0283768; Publication No. 2012 / 0330341; Publication No. 2013 / 0035712; Publication No. 2013 / 0090682; Publication No. 2013 / 0197622; Publication No. 2013 / 0274868; and Publication No. 2014 / 0005714; the European Patent Application No. EP 1651117; and the International Publication No. WO13 / 028579 pamphlet; Publication No. WO13 / 109309 pamphlet; Publication No. WO13 / 152327 pamphlet. These references do not disclose any embodiments of the occlusion device disclosed herein.

[0006] Reference is also made to commonly-owned U.S. Patent Application No. 14 / 699,188, which discloses an apparatus for treating intravascular diseases and is hereby incorporated by reference in its entirety.

[0007] Accordingly, the occluding devices disclosed herein provide LAA treatment and / or improvement while promoting more effective endothelialization around the device, and innovative improvements and several advantages in the field of occluding devices are disclosed herein. Accordingly, the improved LAA occluding device disclosed herein maximizes the occlusion of blood flow entering the left atrial appendage and captures any thrombus inside. Further, the occluding device disclosed herein has a coarse mesh density that allows for improved tissue integration and device stabilization. Other advantages include, but are not limited to, elimination of the need to place a number of coils or framing wires or nitinol cages in the LAA sac and the associated cost effectiveness; a higher level of compatibility with difficult anatomical structures that do not conform to current devices that require a significant amount of space in the left atrial space adjacent to the LAA; and significant time savings opportunities by using a single implant.

[0008] All documents and references cited herein as well as the patent documents referenced are hereby incorporated by reference into this specification.

Summary of the Invention

Means for Solving the Problems

[0009] The inventor has designed an occluding device for providing LAA treatment. Thus, the occluding device of the present invention is for promoting stabilization and more effective endothelialization around the device, is configured to maximize the occlusion of blood flow to the LAA, and captures thrombus inside.

[0010] Disclosed herein is an occluding device comprising: (a) a substantially solid marker band having an inner diameter and an outer diameter, a proximal end and a distal end; and (b) an elastic mesh body attached within the marker band, the body having a length y, the body including a mass of additional elastic mesh material having a length x, y being greater than x, the body extending distally from the marker band, the body having a first delivery shape and a second expandable deployment shape.

[0011] In one embodiment, the elastic mesh body includes a double mesh layer. In a further embodiment, the double mesh layer is a double mesh layer folded in the circumferential direction.

[0012] In one embodiment, the elastic mesh body has a coarse mesh density for improved tissue integration and / or stabilization of the occluding device.

[0013] In another embodiment, the elastic mesh body and the mass of additional elastic mesh material are different metals.

[0014] In another embodiment, the elastic mesh body is composed of a superelastic material. In a further embodiment, the elastic mesh body is composed of nitinol. In yet another embodiment, the elastic mesh body is composed of DFT platinum core nitinol.

[0015] In another embodiment, the mass of additional elastic mesh is composed of a superelastic material. In a further embodiment, the mass of additional elastic mesh is composed of nitinol. In yet another embodiment, the mass of additional elastic mesh is composed of DFT platinum core nitinol.

[0016] In another embodiment, the marker band includes a rigid member.

[0017] In another embodiment, the marker band includes a rigid member selected from the group consisting of a ring, a collar, and a suture thread.

[0018] In another embodiment, the marker band is reinforced.

[0019] In another embodiment, the occluding device is a left atrial appendage (LAA) occluding device.

[0020] Also disclosed herein is a kit including the occluding device disclosed herein and delivery means for deploying the occluding device.

[0021] Further disclosed herein is a method for manufacturing and / or delivering and / or deploying the occlusion devices disclosed herein.

[0022] In other embodiments, the occlusion devices of the preceding paragraphs can incorporate any of the embodiments disclosed previously or hereinafter.

[0023] The summary of the invention is not intended to define the scope of the claims nor to limit the scope of the invention.

[0024] Other features and advantages of the invention will become apparent from the following drawings, detailed description of the invention, and claims. BRIEF DESCRIPTION OF THE DRAWINGS

[0025]

Figure 1

Figure 2

[0026] The invention is shown in the drawings and the description in which like elements are assigned the same reference numerals. However, while specific embodiments are shown in the drawings, the invention is not intended to be limited to the specific embodiments disclosed. Rather, the invention is intended to cover all modifications, alternative configurations, and equivalents that fall within the spirit and scope of the invention. Thus the drawings are illustrative and not restrictive.

[0027] Unless otherwise defined, all technical terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this technology belongs.

[0028] The practice examples of the LAA occlusion devices disclosed herein provide treatment and / or improvement of the LAA. Such occlusion devices are delivered endovascularly to the LAA site (sac and / or cavity) via a catheter or other delivery modality such that the deployed shape of the occlusion device forms a liner that seals at least the opening and / or the inside of the LAA sac, and a substantially solid marker band promotes more effective endothelialization around the device while traversing the opening of the LAA sac or cavity.

[0029] In an exemplary delivery method of the occlusion device disclosed herein, a catheter is introduced into the left atrial space having a left atrial appendage (LAA). A blood clot has formed in the left atrial appendage (LAA). The LAA generally includes an opening (or neck portion) of the LAA and a muscular sac or cavity of the LAA. The catheter tip is positioned adjacent to the opening of the LAA so as to be able to deploy the occlusion device. The occlusion device disclosed herein is composed of an elastically expandable mesh with a low profile like an inverted mushroom, effectively lining the inside of the LAA sac, thereby occluding the LAA by promoting endothelialization around the device.

[0030] For the purposes of the disclosure herein, the term "low profile" means that the elastic mesh body of the device has a height of about 10-20% of its width in free air, and thus in its deployed shape, the elastic mesh body lies flat in a flat manner like an inverted mushroom even when expanded, strikes the tissue wall of the LAA cavity, and as a result, is arranged to at least partially cover the inner surface of the LAA cavity. In this way, the opening and / or the inside of the LAA sac or cavity is sealed, thereby occluding the LAA.

[0031] For the purposes of the disclosure herein, the term "corresponding to" means that there is a functional and / or mechanical relationship between things that correspond to each other. For example, an occlusion device delivery system corresponds to (or is compatible with) an occlusion device for its deployment.

[0032] For the purposes of the disclosure of this specification, the term "occlusion device" is interchangeable with and / or may be interchangeable with terms such as, but not limited to, "device" or "occlusion device system" or "occlusion system" or "system" or "occlusion device implant" or "implant", etc.

[0033] Occlusion device delivery systems are well known in the art and are readily available. For example, such delivery techniques can be found in, but are not limited to, U.S. Patent Nos. 4,991,602; 5,067,489; 6,833,003; U.S. Patent Application Publication Nos. 2006 / 0167494; and 2007 / 0288083, the teachings of each of which are incorporated herein. For the purposes of the present invention, any type of occlusion device delivery means and / or delivery system and / or delivery technique and / or delivery mechanism and / or detachment (and / or attachment) means and / or detachment system and / or detachment technique and / or detachment mechanism may be utilized and / or may be modified to be compatible (corresponding) with the occlusion device disclosed herein. Exemplary occlusion device delivery mechanisms and / or systems include, but are not limited to, guide wires, pusher wires, catheters, microcatheters, etc. Exemplary occlusion device detachment mechanisms include, but are not limited to, fluid pressure, electrolytic mechanisms, hydraulic mechanisms, interlock mechanisms, etc. In one embodiment, the occlusion device disclosed herein is used in an electrolytic detachment method. Electrolytic detachment is well known in the art and can be found, for example, in U.S. Patent Nos. 5,122,136; 5,423,829; 5,624,449; 5,891,128; 6,123,714; 6,589,230; and 6,620,152. Exemplary embodiments of the occlusion device disclosed herein are shown in FIGS. 1-2.

[0034] Exemplary embodiments of the occlusion device disclosed herein are shown in FIGS. 1-2.

[0035] Figure 1 shows an exemplary embodiment of an occlusion device disclosed herein for promoting more effective endothelialization around the device. The occlusion device disclosed herein is composed of an expandable elastic mesh for effectively lining (or coating) the inside of the LAA sac, thereby occluding the LAA by promoting endothelialization around the device. The occlusion device herein includes a main body 20 of an elastic mesh composed of a single mesh layer folded circumferentially to form a double mesh layer. Such a main body 20 extends distally from the marker band 40 and has a length y. The ends of the double mesh layer are attached within the marker band 40. In one embodiment, the ends of the mesh are attached to the proximal end 90 of the marker band 40 and the main body 20 extends distally. In another embodiment, the ends of the mesh are attached to the distal end 100 and the main body 20 extends distally. The main body 20 includes therein a mass 30 (additional mesh mass) of elastic mesh material having a length x. In such an exemplary configuration of the occlusion device disclosed and shown herein, y is longer than x. Even in the expanded or deployed shape of the device, the main body 20 maintains a low-profile shape with respect to the sac 50 of the LAA, and the main body 20 of the device is present inside the sac 50 of the LAA (and lines the wall 70 of the LAA tissue) when deployed. As is accepted in the art, such x and y measurements of the length of such an occlusion device are measured in free air. An exemplary range of the length (y) of the main body 20 of the occlusion device is about 20 to 50 millimeters (mm), and an exemplary length (x) of the mass 30 included within the main body 20 is smaller than the value of the length y. In one embodiment, the main body 20 of the elastic mesh is attached inside / within a substantially solid marker band 40, and the main body 20 extends distally from the marker band 40. Such a configuration of the marker band 40 with respect to the main body 20 gives the device the ability to seal the opening 80 of the LAA and thus effectively occlude the LAA.

[0036] FIG. 2 shows an exemplary embodiment of an occlusion device disclosed herein for treating and / or improving the LAA, deployed within the sac 50 of the LAA. The configuration as shown in both FIGS. 1 and 2 provides the ability of the device to seal the opening 80 of the LAA sac and effectively occlude the LAA. In this embodiment, the mesh body 20 of the device lines the wall 70 of the LAA in a low-profile manner (lying flat like an upside-down mushroom). Thus, even in the deployed shape of the device as disclosed herein and shown in FIG. 2, the distance y is longer than the distance x. In one embodiment, a catheter sized 12F or less is used for deployment of the device disclosed herein. In another embodiment, electrolytic delivery and / or deployment and / or detachment by an electrolytic wire through the left atrial space adjacent to the LAA is used for the device disclosed herein. Electrolytic detachment means and methods as disclosed in U.S. Patent No. 5,122,136 are well known in the art.

[0037] The low-profile deployed shape of the body 20 of the device provides a fixation device for the occlusion device without interfering with the flow of fluid through the left atrial space. This mechanism of action allows the double layer of the mesh body 20, which is expandable in the shape of an upside-down mushroom in its deployed shape, to line the inner wall 70 of the sac 50 of the LAA and promote endothelial growth through the open mesh density formed within the mesh body by the mesh body 20 and its mass 30 of additional mesh. Such a configuration maximizes the shielding of blood flow to the LAA and captures any blood clots 60 inside, triggering endothelialization around the device and / or endothelial growth around the body 20 of the device. The combination of the mass 30 of mesh within the double mesh layer 20 / 30 of the body Rather, it functions as an effective shield within the LAA, i.e., as an improved coated area on the implant's cap that further reduces blood flow. Such a device also functions as a stabilizing device, preventing movement or force transmission through the mesh during expansion. This has several advantages including, but not limited to, fixing the device without requiring any additional material (mesh or otherwise) within the left atrial space, providing unobstructed fluid flow, and / or promoting the development of neointima across the opening 80 of the LAA. Thus, other than the mesh body 20 that includes the additional mass of mesh 30 within the body 20 and extends from the marker band 40 necessary for the device to be fixed or stabilized within the LAA, there are no additional mesh material components.

[0038] Such a configuration promotes sealing of the opening 80 of the LAA and thus the formation and / or healing of the thrombus 60 and / or the contraction of the sac 50 of the LAA, which is particularly advantageous when the size or mass of the thrombus 60 is causing pain or other side effects to the patient. Such a configuration is also advantageous as it requires a minimal amount of elastic mesh material, thereby eliminating the need to fill or substantially fill the space within the sac 50 of the LAA in a spherically radially expanded manner. Such an occlusion device is also suitable for compatibility across a wide range of LAA morphologies, as it is well known and generally accepted that the size of the LAA varies considerably and is not perfectly round. Advantageously, an occlusion device as disclosed herein has a minimal amount of material or less material than current standard devices, thereby minimizing the need for anticoagulant therapy and / or reducing the risk of thromboembolism.

[0039] In another embodiment of the occlusion device disclosed herein, the elastic mesh body 20 of the elastic mesh includes a relatively uniform distribution of wire mesh strands or braids such as, but not limited to, a 72 nitinol (NiTi) wire mesh strand braided configuration. In other embodiments, the occlusion device includes wire mesh strands or braids in the range of 36 - 144 NiTi strand braided configurations.

[0040] In another embodiment of the occlusion device disclosed herein, the additional mass 30 of elastic mesh housed within the body 20 includes a relatively uniform distribution of wire mesh strands or braids, such as, but not limited to, a 72 Nitinol (NiTi) wire mesh strand braided configuration. In other embodiments, the mass 30 of the occlusion device includes wire mesh strands or braids in the range of a 36 - 144 NiTi strand braided configuration. In one embodiment, the elastic mesh of the body 20 of the device is composed of a dissimilar metal compared to the metal within the additional elastic mesh of the mass 30 within the body 20.

[0041] In another embodiment, the mesh density of the inner mass 30 is a double mesh layer and is greater (or higher) than the mesh density of the outer double mesh layer of the body 20.

[0042] The occlusion device disclosed herein functions like an endothelial cell scaffold across the opening 80 of a blood vessel or the LAA, thereby reducing blood flow by about 60% sufficient to cause blood clot formation and / or healing of the LAA, and is composed of an elastic mesh material with a mesh density sufficient for this purpose. For the purposes of the present invention, the term "mesh density" means the level of porosity of the mesh device or the ratio of metal to open area. Mesh density is related to the number and size of the openings or pores in the mesh, and is also related to the degree to which the pores open or close in situations where the openness of the openings or pores changes between delivery and deployment. Generally, a high mesh density region of an elastic mesh material has a metal area of about 70% or more and an open area of about 60% or less.

[0043] In one embodiment, the body 20 of the elastic mesh has a "coarse mesh density" for improved tissue integration and / or stabilization of the occlusion device. The coarse mesh density is higher than about 40% open area within the mesh. The coarse mesh density represents the porosity of the mesh layer 1 The picks per inch (PPI) is typically known to be a low number, about 40 - 80. PPI is the number of repeated crossings of the braided material in linear inches. A high number of repeats (or PPI), typically about 100 - 180, is an indication of a dense mesh. A lower number of repeats (or PPI) is an indication of a porous (coarse) mesh. In further embodiments, the body 20 of the elastic mesh is composed of a superelastic material such as nitinol, but is not limited thereto. In yet another embodiment, the body 20 of the elastic mesh is composed of DFT platinum core nitinol. In other embodiments, when the body 20 of the mesh is composed of nitinol, the mass 30 within that body 20 of the mesh is composed of DFT platinum core nitinol. In still other embodiments, when the body 20 is constructed of DFT platinum core nitinol, the mass 30 within that body 20 of the mesh is composed of nitinol. DFT platinum core nitinol is used to enhance visualization of the device during deployment and implantation.

[0044] Figures 1 and 2 also show the position on the occluding device of the present invention of the marker band 40 having a proximal end 90 and a distal end 100. The marker 40 is attached to the body 20 of the occluding device, and the body extends from the distal end 100 of the marker band 40. In Figure 2, the proximal end 90 of the marker band 20 is shown positioned across the opening 80 of the LAA to be treated like a bridge, which, when combined with the characteristics of the body 20 of the low-profile elastic mesh 14 including the additional mass 30 of mesh, creates a coarse mesh density effect, thereby promoting more effective endothelialization around the device. Other advantages include eliminating the need to incorporate additional mesh material extending proximally from the marker band to seal the opening 80 of the LAA or to secure the device in the left atrial space. Further, positioning the proximal end 90 of the marker band 40 across the opening 80 of the LAA advantageously provides for complete retrievability of the device.

[0045] In one embodiment of the device disclosed herein, the coiled core wire (or guide wire) of a catheter (or micro - catheter) is attached to the distal end 90 of the body 20 of the double - mesh layer inside the marker band 40. The winding of the coil maintains a constant diameter (φ) so as not to affect the flexibility or rigidity of the delivery catheter or micro - catheter or guide wire. In certain embodiments, an FEP (fluorinated ethylene propylene) heat - shrinkable tube wraps the coiled portion of the core wire. Using numerous readily available and well - known attachment techniques in medical device technology, the distal end of the core wire can be attached inside the marker band 40 and / or to an occlusion device or implant. Such known techniques are also used to attach the ends of the body 20 of the elastic mesh to the marker band 40 and / or inside / within it. Such attachment techniques include, but are not limited to, adhesives, laser melting, laser tacking, spot, and / or continuous welding. In one embodiment, an adhesive is used to attach the distal end of the core wire inside the marker band 40. In another embodiment, an adhesive is used to attach the ends of the body 20 of the elastic mesh to the marker band 40 and / or inside / within it. In a further embodiment, the adhesive is an epoxy material that cures or hardens upon application of heat or UV (ultraviolet) radiation. In yet a further embodiment, the epoxy is a thermosetting two - part epoxy such as EPO - TEK® 353ND - 4 available from Epoxy Technology, Inc. (14 Fortune Drive, Billerica, Mass). In additional embodiments, such an adhesive or epoxy material encapsulates the junction of the core wire inside the marker band 40, enhancing its mechanical stability.

[0046] In another embodiment, during and / or after deployment of the device, the coiled core wire is electrolytically detached at its own electrolytic detachment site in such a way that the device disclosed herein causes the core wire to be cut and / or dissolved by electrolysis at the base of the marker band 40 (or Disconnect in the (zone). Such an action then releases and / or places an occlusion device in the LAA to be treated.

[0047] In one embodiment, the marker band 40 of the occlusion device disclosed herein is a substantially solid collar or rigid member, such as but not limited to a solid ring, composed of materials such as but not limited to gold, platinum, stainless steel, and / or combinations thereof. In another embodiment, a radiopaque material such as but not limited to gold, platinum, platinum / iridium alloy, and / or combinations thereof can be used. Such a marker 40 provides visualization of the device during delivery and placement. The hardness of the marker 40 contributes to the stability of the device within the LAA, prevents the movement or transmission of forces through the elastic mesh of the device, thereby preventing misplacement or accidental movement of the device. The marker 40 is also configured with a junction (core wire attachment portion inside the marker band 40) for cooperating with and detaching / attaching to a corresponding delivery means such as but not limited to a delivery catheter or guide wire and / or pusher wire technology. It also advantageously provides for the complete retrievability of the device disclosed herein.

[0048] In another embodiment, the substantially solid marker band 40 includes a radiopaque material (e.g., such as but not limited to platinum, gold, platinum / iridium alloy, and / or combinations thereof) that facilitates visualization of the occlusion device under fluoroscopy during delivery, placement, and / or deployment. The marker 40 includes a proximal end 90 and a distal end 100. Each arm 20 of the elastic mesh is attached to the marker band 40 and extends from the distal end 100 of the marker band 40. In one embodiment, the marker band 40 may be configured to affect the shape, diameter, and / or curvature of the body 20 of the elastic mesh when the occlusion device is expanded. The marker 40 may be designed in various shapes to affect the overall profile of the occlusion device to ensure proper adhesion of the expanded / deployed occlusion device within the sac 50 of the LAA.

[0049] In some embodiments of the occlusion devices disclosed herein, the marker band 40 is a rigid member such as a ring, a collar (e.g., a collapsed or flat collar, etc.), a band or a suture (e.g., a polymeric suture, etc.). Such a "substantially solid" or "rigid member" functions as a pinch point that gathers the ends of the body 20 of the device. In further embodiments, the marker band 40 is reinforced, and thus the mesh of the device crosses the marker band 40 to provide a continuous profile on the inner surface from the opening 80 of the LAA to the sac 50 of the LAA. Such a reinforced marker band 40 includes, but is not limited to, a plastically deformable shape memory elastic mesh material, a wire braided mesh material (including various mesh braiding structures such as, but not limited to, 2-strand over-1-strand under, 1-strand under-1-strand over, 1-strand over-2-strand under, etc.), a laser cut mesh material, and / or a combination of materials including them.

[0050] The substantially solid marker band 40 facilitates the delivery and positioning of the occlusion device adjacent to the opening 80 of the LAA by providing a rigid member that moves towards the neck portion. Further, in some embodiments, the substantially solid marker band 40 provides visibility under fluoroscopy, thereby enabling more accurate visualization and accurate placement of the device.

[0051] In certain embodiments, the elastic mesh of the occlusion device disclosed herein can be filled with a plugging material such as, but not limited to, a liquid agent and / or microparticles to promote coagulation and closure of the LAA. Examples of liquid agents and microparticles include, but are not limited to gelatin foam, polyvinyl alcohol particles, trisacryl gelatin microspheres, N-butyl-2-cyanoacrylate, ethylene vinyl alcohol copolymer, calcium alginate gel, absolute alcohol, etc.

[0052] In other embodiments, the occlusion devices disclosed herein may further incorporate and / or be used with auxiliary elements and / or members well known in the art such as coiling techniques, framing coils, embolization agents, additional markers, polymers, absorbent polymers, and / or combinations thereof.

[0053] Elastic mesh materials for the design and / or manufacture of occlusion devices are readily available and well known to those skilled in the art. Thus, elastic mesh materials extend from a variety of available materials including, but not limited to, nickel titanium (known as nitinol or NiTi), stainless steel, polymers, and / or combinations thereof. Exemplary families of medical polymers include, but are not limited to, polymers such as polyphosphazenes, polyanhydrides, polyacetals, poly(orthoesters), polyphosphoesters, polycaprolactone, polyurethanes, polylactides, polycarbonates, polyamides, and / or combinations thereof. (See, e.g., J Polym Sci B Polym Phys. Author manuscript; available at PMC June 15, 2012.)

[0054] In one exemplary embodiment, the elastic mesh material is formed from woven strands of a polymeric material such as, but not limited to, nylon, polypropylene, or polyester. The polymer strands can be filled with a radiopaque material that enables a physician treating an aneurysm to visualize the position of the device within the vasculature by fluoroscopy. The radiopaque filler material preferably includes a radiopaque dye such as bismuth trioxide, tungsten, titanium dioxide, or barium sulfate, or iodine. The elastic mesh material can be formed by strands of the radiopaque material. The radiopaque strands enable a physician and / or radiologist to visualize the position of the mesh by fluoroscopy without using the filled polymeric material. Such radiopaque strands can be formed from materials such as, but not limited to, gold, platinum, a platinum / iridium alloy, and / or combinations thereof. In one embodiment, the elastic mesh material is composed of 10% - 20% platinum core NiTi. In another embodiment, the elastic mesh material is composed of 10% platinum core NiTi, 15% platinum core NiTi, or 20% platinum core NiTi. The structure of 10% platinum core NiTi is sufficient to provide a ghost image of the occluding device under x-rays.

[0055] Such configured combination wires or composite wires having a radiopaque core and a non-radiopaque outer layer or casing are readily available as DFT® (drawn-filled tube) wires, cables or ribbons and are well known in medical devices and metal technology. DFT® wires are metal-metal composites configured to combine the desired physical and mechanical properties of two or more materials in a single wire. By placing a more radiopaque but more ductile material in the core of the wire, the NiTi outer layer can provide a composite wire having similar mechanical properties to a 100% NiTi wire. DFT® wires are available from Fort Wayne Metals Corp. (Fort Wayne, Ind., U.S.A.). Also see, for example, the journal article by Schaffer entitled Biocompatible Wire in Advanced Materials & Processes, October 2002, pages 51-54, which is incorporated herein by reference.

[0056] When the elastic mesh material is formed from radiopaque metal strands, the strands may be coated by polymer coating or extrusion. Coating or extrusion onto the radiopaque wire strands provides visualization by fluoroscopy, but may increase the resistance of the strands to bending fatigue and also increase the lubricity of the strands. The polymer coating or extrusion is, in one embodiment, coated or treated with an agent that tends to resist clotting, such as heparin. Such clot-resistant coatings are generally known. The polymer coating or extrusion can be any suitable extrudable polymer or any polymer that can be applied as a thin coating such as Teflon® or polyurethane.

[0057] In yet another embodiment, the strands of the elastic mesh material are formed using both metal and polymer braided strands. By combining metal strands and polymer strands in the braiding, the flexibility of the mesh changes. The force required to deploy and / or collapse such a mesh portion is significantly reduced compared to the force required for a mesh portion containing only metal mesh strands. However, the radiopaque properties of the mesh for fluoroscopic visualization are retained. Metal strands forming such a device include, but are not limited to, stainless steel, gold, platinum, platinum / iridium, nitinol, and / or combinations thereof. The polymer strands forming the device can include nylon, polypropylene, polyester, Teflon®, and / or combinations thereof. Further, the polymer strands of the mesh material can be chemically modified to make them radiopaque using known techniques such as, but not limited to, by depositing gold on the polymer strands or by using ion beam plasma deposition of suitable metal ions on the polymer strands.

[0058] The elastic mesh material can also be formed of filaments or strands of various diameters and / or various flexibilities. By varying the size or flexibility of the polymer strands, the flexibility characteristics of the mesh upon deployment can also be varied. By varying the flexibility characteristics, both the deployed form and the folded form of the body 20 of the elastic mesh can be changed or modified to substantially any desired shape.

[0059] The mesh can be formed from both polymer strands or filaments and metal strands or filaments, and can also be formed using filaments of different polymer materials. For example, different polymer materials having different flexibility characteristics can be used to form the mesh. This changes the flexibility characteristics of the device to alter the resulting configuration of the mesh body 20 in both the deployed and folded positions. Such medical polymers are readily known and available in the art and can be derived from polymer families such as, but not limited to, polyphosphazenes, polyanhydrides, polyacetals, poly(orthoesters), polyphosphoesters, polycaprolactone, polyurethanes, polylactides, polycarbonates, polyamides, and / or mixtures thereof.

[0060] An elastic mesh material suitable for use within the device can take the form of a flat woven sheet, a knitted sheet, or a laser cut wire mesh. Generally the material comprises a set of two or more substantially parallel strands, and one set of parallel strands should be at a pitch of 45 to 135 degrees relative to the other set of parallel strands. In some embodiments, the two sets of parallel strands forming the mesh material are substantially perpendicular to each other. The pitch and overall structure of the mesh material may be optimized to meet the performance requirements of the occlusion device.

[0061] The wire strands of the metal fabric used in the present invention are elastic and substantially It should be formed of a material that can be heat-treated to be set thereto. Materials that are considered suitable for this purpose include cobalt-based low thermal expansion alloys called Elgiloy® (available from Elgiloy Specialty Metals (Elgin, Illinois)) in the field of occlusion devices, nickel-based high-temperature and high-strength "superalloys" commercially available under the trade name Hastelloy® from Haynes International, nickel-based heat-treatable alloys sold under the name Incoloy® by International Nickel, and multiple different grades of stainless steel. An important factor in selecting a material suitable for the wire is that when subjected to a given heat treatment, the wire retains an appropriate amount of deformation induced by the forming surface (or shape memory described below).

[0062] One class of materials that meet these conditions are so-called shape memory alloys. Such alloys tend to have a temperature-induced phase change that causes the material to have a preferred shape that can be fixed by heating the material above a certain transition temperature that induces a phase change in the material. When the alloy is cooled, the alloy "remembers" the shape during heat treatment and tends to assume the same and / or similar shapes unless constrained from doing so.

[0063] One particular shape memory alloy for use in the present invention is Nitinol, which is an almost stoichiometric alloy of nickel and titanium that may also contain small amounts of other metals to achieve desired properties. NiTi alloys such as Nitinol include appropriate compositions and handling requirements and are well known in the art, and such alloys need not be considered in detail here. For example, U.S. Patent Nos. 5,067,489 and 4,991,602, the teachings of which are incorporated herein by reference, consider the use of shape memory NiTi alloys in guide wire-based techniques. Such NiTi alloys are commercially available and are better known for handling such alloys than other known shape memory alloys, and are thus at least partially preferred. NiTi alloys are also very elastic. In fact, they are said to be known as "superelastic" or "pseudoelastic". This elasticity serves to help the occlusion devices disclosed herein return to their previous expanded configuration for deployment.

[0064] The wire strands can comprise standard monofilaments of a selected material, i.e., standard wire stock can be used. In some embodiments, 72 wire strands and / or a 72-strand braided configuration can be used. In other embodiments, the occlusion device includes a wire mesh strand or braid in the range of 36 to 144 NiTi strand braided configurations. However, if desired, the individual wire strands can be formed from a "cable" composed of a plurality of individual wires. For example, cables formed from metal wires with several wires spirally wound around a central wire are commercially available, and NiTi cables with an outer diameter of 0.003 inches or less can be purchased. One advantage of certain cables is that they tend to be "softer" than monofilament wires having the same diameter and formed from the same material. Further, the use of cables can increase the effective surface area of the wire strands, which tends to promote thrombus formation.

[0065] In some embodiments, the elastic mesh may be formed uniformly from the same material. However, such material may have different knitting, stitching, braiding, and / or cutting structures.

[0066] In other embodiments, the occlusion devices disclosed herein, when appropriately scaled, can be used in endovascular techniques, such as for the treatment and / or improvement of aneurysms, particularly large and irregularly sized aneurysms, and to promote more effective endothelialization around the device. In this regard, reference is made to commonly owned U.S. Patent Application No. 14 / 699,188. This patent application is incorporated herein by reference. Further, the occlusion devices disclosed herein, when appropriately scaled, can be used in the process of peripheral embolization (a process well known in the art and known to involve the interruption of blood flow distal to a particular vascular site) for the treatment and / or improvement of, for example, any associated lesions requiring vascular occlusion for peripheral arterial or venous pathologies and / or their treatment.

[0067] The occlusion devices of the present invention can incorporate reasonable design parameters, features, modifications, advantages, and variations that will be readily apparent to those of ordinary skill in the art of occlusion devices.

Claims

1. (a) a substantially solid marker band having an inner diameter and an outer diameter, a proximal end and a distal end; and (b) an elastic mesh body attached within the marker band, the body having a length y, the body including a mass of additional elastic mesh material having a length x, y being greater than x, the body being a bilayer of elastic mesh folded back on itself, having folded-back ends of the elastic mesh, all of the folded-back ends of the bilayer of elastic mesh being attached within the marker band, the body extending distally from the marker band and having a first delivery shape and a second expandable, inverted mushroom-like deployment shape, an occlusion device comprising the elastic mesh body.

2. The occlusion device according to claim 1, wherein the body includes a circumferentially folded bilayer mesh layer.

3. The occlusion device according to claim 1, wherein the elastic mesh body and the mass of additional elastic mesh material are different metals.

4. The occlusion device according to claim 1, wherein the elastic mesh body is composed of nitinol.

5. The occlusion device according to claim 1, wherein the mass of additional elastic mesh is composed of nitinol.

6. The occlusion device according to claim 1, wherein the marker band includes a rigid member.

7. The occlusion device according to claim 1, wherein the marker band includes a rigid member selected from the group consisting of a ring, a collar, and a suture thread.

8. The occlusion device according to claim 1, wherein the marker band is reinforced.

9. The occlusion device according to claim 1, which is a left atrial appendage (LAA) occlusion device.

Images