Systems and methods for treating aneurysms

Abstract

A device for treating intravascular aneurysms includes an occlusion element positioned on a wire, the occlusion element including a cover for covering the neck of the aneurysm and an internal anchoring member. The cover is configured to expand from a compressed configuration to an expanded configuration within the tube as it is advanced forward from the distal end of the tube to cover the neck of the aneurysm. The cover includes a sphere of mesh material formed into a hemisphere containing two mesh layers formed by folding the upper part of the sphere into the bottom part of the sphere. The internal anchoring member is configured to be coupled to a second surface of the cover, extending therefrom, and in contact with the inner surface of the aneurysm. The internal anchoring member may be a cylindrical stem extending from the central portion of the cover. [Selection Diagram] Figure 25

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims the benefit of priority of U.S. Patent Application No. 15 / 875,767, filed on Jan. 19, 2018, the entire disclosure of which is incorporated herein by reference in its entirety.

Background Art

[0002] An aneurysm is an abnormal dilation or weakening of a blood vessel, often an artery, and can have many complications. The dilation of the blood vessel can disrupt or exert pressure on surrounding tissues. In the brain, this can cause various side effects such as visual impairment, speech impairment, balance disorder, etc. Further, an aneurysm forms a space not along the main flow path of the blood flowing through the blood vessel. Thus, an aneurysm can function as a place where blood stagnates and, due to the vortex flow, can contribute to the formation of thromboembolism. When an aneurysm ruptures, it can cause internal bleeding.

[0003] An aneurysm can be treated from the outside by open surgery. The procedure typically involves closing the entrance or "neck" of the aneurysm with a device such as a vascular clamp or ligature thread. However, the reconstructive surgical procedure can be very invasive and can lead to trauma to adjacent tissues and other side effects.

[0004] Aneurysms may also be treated by endovascular procedures. In one procedure, a detachable length of wire (e.g., a coil) is inserted into the aneurysm's interior space using a catheter. The coil is intended to fill the aneurysm's interior space to reduce blood flow to the aneurysm, which stagnates and promotes clotting of the aneurysm. In the case of large cerebral aneurysms, filling the aneurysm with multiple coils can induce a mass effect, which can cause brain swelling and independently create new symptoms. In another procedure, aneurysms with relatively large necks can be used with a secondary stent to assist in the retention of the coil within the aneurysm. This approach requires additional antithrombotic agents and cannot be used to treat ruptured aneurysms. In another procedure, a temporary balloon inflated within the vessel holds the coil in the aneurysm's interior space. Once the coil is secured, the balloon is deflated and removed. In yet another procedure, a stent device is placed in the artery to facilitate blood flow past the aneurysm. This causes blood flow inside the aneurysm to stagnate and a clot to form inside the aneurysmal space. However, the side branch of the main artery in which the stent device is placed may become trapped or "restricted," thereby preventing access to the side branch. In other cases, the side branch may become clogged, causing a stroke. Furthermore, the procedure generally requires the use of additional antithrombotic agents, which limits the use of the device in treating ruptured aneurysms. Stent devices are generally formed with a relatively tight weave. Although the tight weave increases the effectiveness of the stent device as it diverts blood flow, it also impedes or prevents access to the aneurysmal space or restricted artery. If the aneurysm does not become a clog, an embolic device cannot be placed into the aneurysm because the aneurysm will be occluded by the stent device. Sequelae may need to be treated with additional procedures, such as placement of additional stents or open surgery.

[0005] All procedures that include the step of packing the aneurysm space will suffer from several common drawbacks. First, a large number of coil wires are required to fill the aneurysm space, thereby taking time and increasing the time until the procedure is completed. Further, since the coil can shrink over time, it will occupy a smaller percentage of the total volume of the aneurysm. If the coil is compressed sufficiently, recurrence of the aneurysm is a concern and further treatment may be required.

[0006] It would be advantageous to provide an improved system and method for treating an aneurysm. SUMMARY OF THE INVENTION

[0007] One embodiment relates to an apparatus for treating an aneurysm within a blood vessel, the apparatus including an occlusion element disposed on a wire, the occlusion element including a cover for covering the neck of the aneurysm and an internal anchoring member. The cover is configured to expand from a compressed configuration within the tube to an expanded configuration when advanced forward from the distal end of the tube to cover the neck of the aneurysm. The cover includes a sphere of mesh material formed as a hemisphere including two mesh layers formed by folding the upper portion of the sphere into the bottom of the sphere. The internal anchoring member is coupled to and extends from a second surface of the cover and is configured to contact the inner surface of the aneurysm. The internal anchoring member can be a cylindrical stem extending from the central portion of the cover.

[0008] One embodiment relates to an apparatus for treating an aneurysm in a blood vessel, including an occlusion element disposed on a wire. The occlusion element includes a cover for covering the neck of the aneurysm, an internal anchoring member for contacting the inner surface of the aneurysm, and a central stem connecting the cover and the internal anchoring member. The occlusion element is coupled to the wire at the outer surface of the cover. The cover and the internal anchoring member are configured to expand from a compressed configuration while disposed within the tube to an expanded configuration when advanced forward from the distal end of the tube so as to be positioned within the aneurysm. The cover and the internal anchoring member have substantially similar diameters, and the central stem has a diameter smaller than the diameters of the cover and the internal anchoring member.

[0009] One embodiment relates to an apparatus for treating an aneurysm in a blood vessel, including an occlusion element disposed on a wire. The occlusion element includes a cover for covering the neck of the aneurysm and an internal anchoring member. The cover is configured to expand from a compressed configuration within the tube to an expanded configuration when advanced forward from the distal end of the tube to cover the neck of the aneurysm. The cover includes a double-layer mesh including an inner layer folded into an outer layer, such that the inner surface of the inner layer of the cover includes a concave surface. The internal anchoring member is directly coupled to and extends from the inner surface of the cover and is configured to contact the inner surface of the aneurysm.

[0010] The present invention can have other embodiments and can be implemented in various ways. Alternative exemplary embodiments relate to other features and combinations of features that can generally be recited in the claims.

[0011] These and other features, aspects, and advantages of the present invention will become apparent from the following description, the appended claims, and the accompanying exemplary embodiments shown in the drawings. The drawings are briefly described below.

Brief Description of the Drawings

[0012]

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[0013] Generally referring to FIGS. 1 - 14, an aneurysm occlusion device configured to treat an aneurysm 10 according to some exemplary embodiments is illustrated. The aneurysm 10 is a bulge that extends outside the wall 13 of the blood vessel 12 and has an internal space 14 that is in fluid communication with the blood vessel 12 through an opening in the neck portion 16. The aneurysm 10 can occur as a part of the blood vessel 12, and its wall 13 is weakened by disease or trauma. In one embodiment, the aneurysm 10 can be present along an artery such as an artery in the skull (e.g., basilar artery, middle cerebral artery, etc.). The aneurysm 10 shown in the figures is for illustrative purposes only, and it will be understood that the occlusion devices described herein can be used to treat aneurysms of various sizes and locations. For example, the aneurysm 10 can be located between two branches of a blood vessel.

[0014] Referring to FIGS. 1 - 3E, an occlusion device 20 according to one exemplary embodiment is illustrated disposed at the neck portion 16 of the aneurysm 10, blocking or preventing the flow of blood between the blood vessel 12 and the internal space 14 of the aneurysm, thereby reducing the likelihood of the aneurysm 10 rupturing. The occlusion device 20 is configured as a low-profile device to minimize interference with surrounding tissues such as the branch 18 of the blood vessel 12. The occlusion device 20 can be composed of a biodegradable or bioabsorbable material and can be configured to promote endothelialization.

[0015] The occlusion device 20 includes an inner cover 22 (e.g., a plate, a thin film, etc.) configured to be disposed within the internal space 14 of the aneurysm 10. The inner cover 22 has an outer diameter that is larger than the diameter of the neck portion 16 when fully expanded. The inner cover 22 is thin, flexible, and concave, and it can be twisted (e.g., crushed) and inserted into the internal space 14 of the aneurysm 10 through the neck portion 16 (e.g., inserted by a catheter) and opened to at least partially occlude the neck portion 16. As used herein, concave means any body formed to have a depression or cavity along one side surface. As shown in FIG. 1, in one exemplary embodiment, the inner cover 22 can be generally dome-shaped. In another embodiment, the inner cover 22 can be another concave shape (e.g., conical shape), disposed on the neck portion 16 and opening towards the internal space 14. In one embodiment, the cover 22 can be disc-shaped.

[0016] The inner cover 22 is formed from a flexible (e.g., soft) biocompatible material, which can be folded into a microcatheter and transported intravascularly to reach the aneurysm 10. The flexibility of the inner cover 22 allows it to conform to the shape of the inner surface 15 of the aneurysm 10 and effectively impede the blood flow between the aneurysm 10 and the blood vessel 12. By closely conforming to the shape of the inner surface 15 of the aneurysm 10, it promotes the adhesion of the inner cover 22 to the tissue of the aneurysm 10 and the formation of new tissue to occlude the neck portion 16.

[0017] The inner cover 22 can be sized to match a particular aneurysm 10. As shown in FIGS. 1-2, the inner cover 22 has a diameter larger than the diameter of the neck portion 16, and the peripheral portion 24 of the inner cover 22 contacts the inner surface 15 of the aneurysm 10. Due to the flexibility of the inner cover 22, the inner cover 22 can be larger than the size of the neck portion 16 without damaging the aneurysm 10 (e.g., without rupturing it). For example, an inner cover with a diameter of about 5 mm can be used to occlude an aneurysm with a neck diameter up to 4 mm, an inner cover with a diameter of about 8 mm can be used to occlude an aneurysm with a neck diameter of 4-6 mm, and an inner cover with a diameter of about 12 mm can be used to occlude an aneurysm with a neck diameter of 6-10 mm.

[0018] In one embodiment, the inner cover 22 can be formed from a biocompatible metal or metal alloy such as platinum, stainless steel, titanium, titanium-nickel alloy (e.g., nitinol), etc. For example, the inner cover 22 can be a concave disc formed from nitinol cut into a sheet shape. The nitinol alloy can be configured to perform a second heat treatment to form a desired concave shape. According to an exemplary embodiment, the thickness of the inner cover 22 can be less than 100 microns and have a desired flexibility. In another embodiment, the inner cover 22 can be formed as a relatively dense mesh such as a 37 micron mesh formed from a plurality of wires or fibers joined together (e.g., welded, soldered, braided, etc.).

[0019] In another embodiment, the inner cover 22 can be formed from a biocompatible polymer such as polytetrafluoroethylene (PTFE), modified polyurethane, silicone, or other suitable polymer. In yet another exemplary embodiment, the inner cover 22 can be formed from a metal or alloy coated with a polymer (e.g., parylene, PTFE, PFE, etc.) to increase lubricity and biocompatibility and reduce thrombus formation. The inner cover 22 can be formed as a fixed sheet or film, or as a relatively dense mesh. In some embodiments, the inner cover 22 can include a nylon sheet perforated with holes by a laser to reduce the bulk portion and provide a matrix for endothelialization. Another embodiment can include two-photon polymerization, i.e., forming an inner cover 22 that directly rides on the delivery system from a three-dimensionally printed biocompatible material, or lying laterally on a framework connected to the delivery system to customize the final shape of the inner cover 22 at the time of treatment.

[0020] Referring to FIGS. 3A - 3D, the manner in which the internal cover 22 according to the exemplary embodiment is deployed by the catheter 30 is shown. Referring to FIG. 3A, the catheter 30 including the push wire 32 travels through the blood vessel 12 to the location of the aneurysm 10. The distal end 34 of the catheter 30 passes through the neck portion 16 and advances into the internal space 14 of the aneurysm 10 or a portion of the blood vessel 12 near the neck portion 16. The push wire 32 is located within the lumen formed in the catheter 30. The catheter 30 may have one lumen, or the push wire 32 may be located within one of several lumens formed inside the catheter 30. The internal cover 22 is coupled to the distal end 36 of the push wire 32 and fits within the lumen in a folded configuration. In the folded configuration, the peripheral portion 24 of the internal cover 22 is located upstream (e.g., near the distal end 34) compared to the central portion 26 to which the push wire 36 is coupled. Referring to FIG. 3B, until the internal cover 22 begins to exit the end 34 of the catheter 30, the push wire 32 moves within the lumen relative to the catheter 30. When the internal cover 22 passes through the end 34 of the catheter 30, it is deployed into a deployed configuration within the internal space 14 (e.g., by the internal spring force of the internal cover 22). The push wire 32 can be moved relative to the catheter 30 by keeping the catheter 30 stationary and advancing (e.g., pressing) the push wire 32, keeping the push wire 32 stationary and pulling the catheter 30 (e.g., withdrawing it from the sheath), or a combination of movements of the catheter 30 and the push wire 32. The internal cover 22 can be located within the blood vessel 12 or within the aneurysm 10 and be partially deployed at the distal end 34 of the catheter 30.

[0021] Referring to FIG. 3C, before the inner cover 22 is fully deployed from the catheter 30, the distal end 34 of the catheter 30 advances into the internal space 14 of the aneurysm 10. Referring to FIG. 3D, with the inner cover 22 fully deployed from the catheter 30, the catheter 30 and / or the push wire 32 are retracted until the inner cover 22 seats on the inner surface 15 of the aneurysm. Referring to FIG. 3E, the distal end 36 of the push wire 32 is detached from the inner cover 22, and the catheter 30 and the push wire 32 are withdrawn from the blood vessel 12, while the inner cover 22 may remain in the neck portion 16 or the lower part of the aneurysm 10. The push wire 32 can be detached from the inner cover 22 by any suitable electrical or mechanical cutting device. Alternatively, the inner cover 22 can be removed by retracting the wire 32, engaging the cover 22 at the distal end of the tube 30, and removing it from the wire 32.

[0022] In one embodiment, the inner cover 22 can be configured to be biased in the direction of an open, expanded position. In another embodiment, the inner cover 22 can include a mesh supported by rib members or splines that radially extend outward from the central portion of the inner cover 22. The rib members or splines can be biased in the direction of the open position of one embodiment. In one embodiment, the rib members and splines operate in an upside-down umbrella mode of operation and are locked in the fully open position once they reach the fully open position.

[0023] Referring to FIGS. 4-5, an occlusion device 120 located at the lower part of the aneurysm 10 according to an exemplary embodiment is illustrated, which interrupts or stops the blood flow between the blood vessel 12 and the internal space 14 of the aneurysm, thereby reducing the possibility of the aneurysm 10 rupturing. The occlusion device 120 is composed of a low-profile device and minimizes the impact on surrounding tissues such as the branches 18 of the blood vessel 12. The occlusion device 120 can be composed of a biodegradable or bioabsorbable material and can be configured to promote endothelialization.

[0024] The occlusion device 120 includes an inner cover 122 (e.g., a plate, a thin film, etc.) similar to the above-described inner cover 22 disposed within the internal space 14 of the aneurysm 10. The occlusion device 120 further includes an internal anchoring member 140 disposed within the aneurysm 10. The internal anchoring member 140 is configured to stop the inner cover 122 within the aneurysm 10 near the neck portion 16. The internal anchoring member 140 is a relatively rigid body that supports the inner cover 122, reducing the possibility that the inner cover 122 will be displaced from the neck portion 16 by the fluid pressure of the blood in the blood vessel 12.

[0025] According to an exemplary embodiment, the internal anchoring member 140 includes one or more windings of a coil formed from a suitable biocompatible metal or alloy (e.g., platinum, stainless steel, nickel-titanium alloy, etc.). The metal coil may be similar to the coils commonly used in endovascular coiling procedures. The internal anchoring member 140 includes at least one coil that is coupled to the inner cover 122 and contacts the inner surface 15 of the aneurysm 10. The windings of the internal anchoring member 140 do not fill the entire internal space 14, or a substantial portion of the internal space 14. Instead, the internal anchoring member 140 may include only a small number of windings. In one exemplary embodiment, the internal anchoring member 140 may include a single winding of a coil. In another embodiment, the anchoring member 140 includes a number of windings that substantially fill the internal space 14. The direction, number, and size of the windings of the internal anchoring member 140 may vary depending on the size and shape of the aneurysm 10.

[0026] Referring to FIG. 5, an internal cover 122 and an internal anchoring member 140 according to an exemplary embodiment are shown disposed within a catheter 30. The internal cover 122 is coupled to the distal end 36 of a push wire 32 and is disposed within the lumen of the catheter 30 in a folded configuration. In the folded configuration, the peripheral portion 124 of the internal cover 122 is positioned upstream (e.g., closer to the distal end 34) compared to the central portion 126 to which the push wire 36 is coupled on the first surface 144. The internal anchoring member 140 is coupled to the second surface 146 of the internal cover 122 opposite the first surface 142 and is positioned within the lumen of the catheter 30 upstream of the internal cover 122.

[0027] The occlusion device 120 including the internal cover 122 and the internal anchoring member 140 is deployed within the aneurysm 10 in a process similar to that described with reference to FIGS. 3A - 3E. When the distal end 34 of the catheter 30 is positioned near the neck portion 16 of the aneurysm 10, the push wire 32 moves within the lumen relative to the catheter 30. Movement of the push wire causes the anchoring member 140 to reach the internal space 14 and coil within the internal space 14.

[0028] In one embodiment, the push wire 32 has a circular solid cross-section and the anchoring member 140 has a coiled cross-section (e.g., like a telephone cord) to facilitate coiling within the internal space 14. In one embodiment, the push wire 32 and the anchoring member 140 have a circular solid cross-section. In one embodiment, the push wire 32 and the anchoring member have a coiled solid cross-section.

[0029] When the spiral shaping of the anchoring member 140 is completed, the inner anchoring member 140 is pushed out of the catheter into the internal space 14 where it contacts the inner surface 15 of the aneurysm 10. The push wire 32 further moves until the inner cover 122 begins to appear from the end 34 of the catheter 30 and expands to an expanded configuration within the internal space 14. Next, the catheter 30 and / or the push wire 32 are retracted until the inner cover 122 seats on the inner surface 15 of the aneurysm 10 and is held in place by the inner anchoring member 140. The distal end 36 of the push wire 32 is separated from the first surface 146 of the inner cover 122, and the catheter 30 and the push wire 32 can be withdrawn from the blood vessel 12, but the inner cover 22 remains with the inner anchoring member 140 that couples to the second surface 146 at the neck portion 16 or the lower part of the aneurysm 10.

[0030] Referring to FIG. 6, in one exemplary embodiment, the anchoring member 140 can have variable stiffness. For example, the inner anchoring member 140 can be relatively flexible at the proximal end 146 and relatively stiff at the distal end 148. The relatively stiff distal end 148 can be configured to reinforce and additionally support the wall of the aneurysm 10. The stiffer portion of the inner anchoring member 140 can be utilized as a structural member to form a structure within the internal space 14 of the aneurysm, and the more flexible portion can be utilized to fill the internal space of the aneurysm and support the inner cover 122. The stiffness of the inner anchoring member 140 can be controlled in various ways, such as by changing the coil thickness, the coil radius, and / or the material used to form the coil.

[0031] The more flexible portion of the inner anchoring member can include a detachable sheath or layer that aids in positioning the stiffer portion inside the anchoring member 140 within the aneurysm 10. The sheath can be removed when the stiffer portion of the inner anchoring member 140 is positioned in place at the distal end 148.

[0032] In one embodiment, the stiffness of the internal anchoring member 140 can vary smoothly or gradually along the length of the internal anchoring member 140 between the distal end 148 and the proximal end 146. In other exemplary embodiments, the internal anchoring member 140 can include two or more distinct regions or portions, each having different stiffness or properties. The internal anchoring member 140 can include markers or other indicia that indicate a transition from one region to another. In one embodiment, the indicia can be external and located on an external shaft that engages a push wire, and each of the external indicia corresponds to a transition from a region having a first stiffness to a region having a second stiffness. In another embodiment, the indicia can be internal and can be a radiopaque indicia (e.g., a platinum coating) on the internal anchoring member 140 between regions.

[0033] In one embodiment, the anchoring member 140 with variable stiffness can be utilized without the internal cover 122. In such an embodiment, the anchoring member 140 fills the internal space 14. In one embodiment, a plurality of anchoring members 140 can be utilized. In one embodiment, the variable stiffness (e.g., thickness) of the first deployed anchoring member 140 is greater than the variable stiffness (e.g., thickness) of the next deployed anchoring member.

[0034] Referring to FIGS. 7 - 10, an occlusion device 220 according to an exemplary embodiment is shown positioned near or within the neck portion 26 and below the aneurysm 20, blocking or stopping the flow of blood between the blood vessel 22 and the internal space 14 of the aneurysm 20, thereby reducing the likelihood of the aneurysm 20 rupturing. The occlusion device 220 is configured as a low-profile device to minimize interference with surrounding tissues such as the side branches 28 of the blood vessel 22. The occlusion device 220 can be constructed of a biodegradable or bioabsorbable material and can be configured to promote endothelialization.

[0035] The occlusion device 220 includes an internal cover 222 (e.g., a plate, a thin film, etc.) disposed within the internal space 14 of the aneurysm 10 similar to the internal covers 22, 122 described above. The occlusion device 220 also includes an internal anchoring member 240 disposed within the aneurysm 10 similar to the internal anchoring member 140 described above. The internal anchoring member 240 is configured to stop the internal cover 222 within the aneurysm 20 near or at the neck portion 16. The occlusion device 220 further includes an external anchoring member 250 disposed within the blood vessel 12 in the vicinity of the aneurysm 10. The external anchoring member 250 provides a relatively rigid body that supports the internal cover 222 and reduces the possibility that the internal cover 222 is displaced from the neck portion 16 by the fluid pressure of the blood in the blood vessel 12.

[0036] Referring to FIG. 7, the external anchoring member 250 according to an exemplary embodiment includes a coil winding 252 formed from a suitable biocompatible metal or alloy (e.g., platinum, stainless steel, nickel-titanium alloy, etc.). The metal coil may typically be similar to the coils used in endovascular coiling procedures. In one embodiment, the winding 252 is coupled to the internal cover 222 and contacts the wall 13 of the blood vessel 12. In one embodiment, the winding 252 is positioned perpendicular to the flow of blood passing through the blood vessel 12. In one embodiment, a plurality of coils or windings 252 may be used.

[0037] Referring to FIG. 8, an external anchoring member 250 according to an exemplary embodiment includes a first winding 254 and a second winding 256. The windings 254 and 256 can be windings of a coil formed from a suitable biocompatible metal or alloy (e.g., platinum, stainless steel, nickel-titanium alloy, etc.). At least one of the windings 254 and 256 is coupled to the inner cover 222 and contacts the wall 13 of the blood vessel 12. The first winding 254 extends around the inner circumference of the blood vessel 12 perpendicular to the flow of blood passing through the blood vessel 12. The second winding 256 is parallel to the flow of blood passing through the blood vessel 12. The second winding 256 is formed from coils with a very small diameter and does not substantially obstruct the flow of blood passing through the blood vessel. In other embodiments, the external anchoring member 250 can include three or more windings. The direction, number, and size of the windings can vary depending on the size and shape of the blood vessel 12.

[0038] Referring to FIG. 9, in another exemplary embodiment, an external anchoring member 250 includes a stent 258 formed from a suitable biocompatible metal or alloy (e.g., platinum, stainless steel, nickel-titanium alloy, etc.) or a suitable biocompatible polymer. The stent 258 is guided by a catheter 30 to a blood vessel 12 near the aneurysm 10 in a folded state. Once deployed inside the blood vessel 12, the stent 258 expands to engage the wall of the blood vessel 12. The stent 258 can be self-expanding or expand with another device such as an inflatable balloon. All or part of the stent 258 can be coated or covered with a radiopaque material such as platinum, and the stent 258 can be visualized (e.g., during or after the placement of the stent 258).

[0039] The stent 258 is not intended to occlude the neck portion 16 of the aneurysm 10 and forms a structure that aids in the placement and anchoring of the inner cover 222. Thus, the stent 258 need not be the same width or wider than the neck portion 16 and can have a relatively short body (e.g., shorter than the width of the neck portion 16 of the aneurysm 10). The stent By having the length of the tether 258 be relatively short, the risk that the external anchoring member 250 will rupture the tissue surrounding a side branch 18 of the blood vessel 12 or the like is reduced. Further, the stent 258 can be in a relatively open configuration that is non-dense and has a variable cell morphology, and can extend proximally from the neck portion 16 into the blood vessel 12. In other embodiments, the stent 258 can be a solid member such as a relatively thin-walled band formed from a metal or alloy.

[0040] In another embodiment, the external anchoring member 250 can be a temporary member that is removed with the catheter 30 after the occlusion device 320 has been positioned at the aneurysm neck portion 16 and attached to the wall of the aneurysm 10. For example, the external anchoring member can be a balloon that inflates with air within the blood vessel 12 near the aneurysm, providing a temporary structure that supports the inner cover 222.

[0041] Referring to FIG. 10, the inner cover 222, inner anchoring member 240, and external anchoring member 250 according to the exemplary embodiment are shown disposed within the catheter 30. The external anchoring member 250 is coupled to the distal end 36 of the push wire 32 and is in a folded configuration, covered within the lumen of the catheter 30. The external anchoring member 250 is coupled to the inner cover 222 and is in a folded configuration, covered within the lumen of the catheter 30 upstream of the external anchoring member 250. The external anchoring member 250 can be adhesively coupled to the inner cover 222, for example. In the folded configuration, the peripheral portion 224 of the inner cover 222 is located upstream of the central portion 226, to which the external anchoring member 250 is coupled on the first surface 244. The inner anchoring member 240 is coupled to the second surface 246 of the inner cover 222 that faces the first surface 242 and is disposed within the lumen of the catheter 30 upstream of the inner cover 222.

[0042] The occlusion device 220, which includes an inner cover 222 and an inner anchoring member 240, is deployed within the aneurysm 20 in the same manner as the process described above with reference to FIGS. 3A - 3E. When the distal end 34 of the catheter 30 is positioned near the neck portion 16 of the aneurysm 10, the push wire 32 moves within the lumen relative to the catheter 30. The inner anchoring member 240 is extruded from the catheter and moves into the inner space 14, where it contacts the inner surface 25 of the aneurysm 20. The push wire 32 moves further until the inner cover 222 begins to emerge from the end 34 of the catheter 30 and expands to assume a configuration that spreads within the inner space 14. Next, the catheter 30 and / or the push wire 32 are retracted until the inner cover 222 seats on the inner surface 25 of the aneurysm 20 and is held in place by the inner anchoring member 240. The push wire 32 moves further until the outer anchoring member 250 emerges from the catheter 30. The outer anchoring member 250 can be, for example, one or more coils 252, 254, or 256, or a stent 258. The distal end 36 of the push wire 32 is disengaged from the outer anchoring member, and the catheter 30 and the push wire 32 can be withdrawn from the blood vessel 22, but the inner cover 22 remains near or at the neck portion 16 of the aneurysm 20, the inner anchoring member 240 is coupled to the second surface 246, and the outer anchoring member 250 is positioned within the blood vessel 12. In other embodiments, the push wire 32 can be directly coupled to the inner cover 222, and the outer anchoring member 250 can be deployed separately (e.g., by another catheter).

[0043] Referring to FIGS. 11 - 14, an occlusion device 320 according to an exemplary embodiment is illustrated as being disposed at the neck portion 16 of the aneurysm 10 to prevent or stop the flow of blood between the blood vessel 12 and the inner space 14 of the aneurysm, thereby reducing the likelihood of the aneurysm 10 rupturing. The occlusion device 320 is configured as a low-profile device to minimize interference with surrounding tissues such as the side branches 18 of the blood vessel 12. The occlusion device 320 can be constructed of a biodegradable or bioabsorbable material and can be configured to promote endothelialization.

[0044] The occlusion device 320 includes an inner cover 322 (e.g., a plate, a thin film, etc.) similar to the above-described inner covers 22, 122, or 222 disposed within the internal space 14 of the aneurysm 10. The occlusion device 320 further includes an outer cover 360 positioned within the blood vessel 12 in the vicinity of the aneurysm 10. The outer cover 360 may be coupled to the inner cover 322, providing a relatively rigid body to support the inner cover. The outer cover 360 reduces the possibility that the inner cover 322 moves away from the neck portion 16 due to the fluid pressure of the blood within the blood vessel 32. The outer cover 360 may be used with, or instead of, another device such as an internal anchoring member 140 or an external anchoring member 250 that fixes the inner cover 322 to the neck portion 16.

[0045] Referring to FIG. 11, the outer cover 360 according to the exemplary embodiment is a relatively thin member (e.g., a plate, a sheet, etc.) formed from a suitable biocompatible member such as a metal or an alloy (e.g., platinum, stainless steel, nickel-titanium alloy, etc.), or a polymer (e.g., PTFE, etc.). According to the exemplary embodiment, the thickness of the outer cover 360 is less than 2 mm. According to a preferred embodiment, the thickness of the outer cover 360 is less than 1 mm. The outer cover 360 has a low-profile body that does not substantially impede the flow of blood passing through the blood vessel 12. The outer cover 360 includes a peripheral portion 362 that contacts the wall 13 of the blood vessel 12 around the neck portion 16 of the aneurysm 10 and a central portion 364 that is positioned at the neck portion 16. The central portion 364 may be integrally formed with the inner cover 322 or may be coupled to the inner cover 322 (e.g., by suitable adhesion). All or part of the outer cover 360 may be coated or covered with a radiopaque material such as platinum so that the outer cover 360 can be visualized (e.g., during or after the placement of the outer cover 360). In an embodiment, the outer cover 360 is attached to the inner cover in a central region having an area smaller than the neck portion 16 (e.g., 90 percent, 75 percent, or 50 percent of the area of the neck portion). In one embodiment, the central region has a circular shape.

[0046] The outer cover 360 is not intended to occlude the neck portion 16 of the aneurysm 10 and forms a structure that assists in stopping the inner cover 322. Thus, the outer cover 360 need not completely cover the neck portion 16. Thus, the outer cover 360 may be shaped such that a portion of the neck portion 16 is uncovered and / or is formed of a porous material (e.g., mesh). Referring to FIG. 12, in one embodiment, the outer cover 360 may be a sheet that completely covers the neck portion 16 such that the peripheral portion 362 of the outer cover 360 extends all around the neck portion 16.

[0047] Referring to FIG. 13, in another embodiment, the outer cover 360 may include a plurality of segments or sections such as the radially rounded protrusions 366 that extend outward from the neck portion 16. Each rounded protrusion 366 may include a central portion 364 located within the neck portion 16 and a peripheral portion 362 that extends beyond the neck portion 16 and contacts the wall 13 of the blood vessel 12.

[0048] Referring to FIG. 14, in another embodiment, the outer cover 360 may include a spiral body 368. The inner winding of the spiral body 368 may form the central portion 364, and the outer winding of the spiral body 368 may form the peripheral portion 362.

[0049] The outer cover 360 may be deployed from the catheter in the same procedure as the inner cover 322. Thus, the outer cover 360 may be configured to couple with the inner cover 322 and be folded within the catheter such that it is covered. The outer cover 360 may be configured within the catheter such that the central portion 364 couples with the inner cover 322 and is located upstream of the peripheral portion 362. The inner cover 322 may be deployed as described with reference to FIGS. 3A - D. Once the inner cover 322 is deployed from the catheter and located within the neck portion 16, the push wire of the catheter may further proceed forward to deploy the outer cover 360. The blood fluid pressure within the blood vessel 12 opposes the outer cover 360 against the wall 13 of the blood vessel 12. In other embodiments, the push wire 32 may couple directly to the inner cover 322 and the outer cover 360 may be deployed separately (e.g., by another catheter).

[0050] Referring to FIGS. 15-16, an occlusion device 420 according to an exemplary embodiment is shown disposed below, such as at the neck portion 16 of the aneurysm 10. The occlusion device 420 includes an internal cover 422 (e.g., a plate, a thin film, etc.) disposed within the internal space 14 of the aneurysm 10. The occlusion device 420 further includes an internal anchoring member 440 and / or an external anchoring member 450 disposed within the aneurysm 10. The internal anchoring member 440 is configured to stop the internal cover 422 within the aneurysm 10 at the neck portion 16. According to an exemplary embodiment, the internal anchoring member 440 includes one or more struts or arms formed from a suitable biocompatible metal or alloy (e.g., platinum, stainless steel, nickel-titanium alloy, etc.). The internal anchoring member 440 is coupled to the internal cover 422, extends beyond the periphery of the internal cover 422, and is configured to contact the internal surface 15 of the aneurysm 10. Thus, the internal anchoring member 440 can be used to assist in positioning the internal cover 422 of the aneurysm 10 having a relatively wide neck 16. The struts or arms of the internal anchoring member 440 do not fill the entire internal space 14 or a substantial portion of the internal space 14. As the aneurysm 10 shrinks as the blood vessel heals, the “mass effect” of the aneurysm 10 decreases, and as a result, the pressure on the surrounding tissue due to the aneurysm is reduced. The orientation, number, and length of the arms of the internal anchoring member 440 can vary depending on the size and shape of the aneurysm 10. Similar to the microcatheter 30 described above, the arms of the internal anchoring member 440 can be configured to be folded together and transported by the microcatheter.

[0051] Referring still to FIGS. 15 - 16, the external anchoring member 450 includes a first portion 452 (e.g., the distal portion) located at the neck 16 and coupled to the inner cover 422, and a second portion 454 (e.g., the proximal portion) located within the blood vessel 12. The external anchoring member 450 is formed from a suitable biocompatible metal or alloy (e.g., platinum, stainless steel, nickel - titanium alloy, etc.) or a suitable biocompatible polymer. All or part of the external anchoring member 450 may be coated or covered with a radiopaque material such as platinum, and the external anchoring member 450 can be visualized (e.g., during or after placement of the external anchoring member 450). The external anchoring member 450 is guided to the blood vessel 12 near the aneurysm 10 by a catheter in a folded state (e.g., straight). Once deployed within the blood vessel 12, the external anchoring member 450 expands such that at least a portion of the external anchoring member presses against the wall of the blood vessel 12. The external anchoring member 450 can be formed as a single continuous spiral, and the windings of the spiral can be formed to have various characteristics (e.g., diameter, thickness, flexibility, etc.). For example, the first portion 452 can be formed as a coil with a relatively small diameter and flexibility, while the second portion 454 can be formed as a large, relatively rigid coil, providing a radially outwardly increasing force to dispose the external anchoring member 450 along the wall 13 of the blood vessel 12.

[0052] Referring to FIG. 17, a portion of the external anchoring member 460 according to another exemplary embodiment can be formed as a double - spiral. According to other exemplary embodiments, the external anchoring member can be of various other shapes (e.g., a spider - web shape, a star shape, etc.), imparting the desired flexibility and supporting the inner cover at the neck portion of the aneurysm.

[0053] Referring to FIGS. 18A - 18B, the inner cover 470 for an occlusion device according to another exemplary embodiment can be a star - shaped body. The inner cover 470 is formed by being folded along a predefined fold line (e.g., by creasing, perforating, molding).

[0054] Referring to FIG. 19, an occlusion device 480 having an external anchoring member 482 is illustrated. The external anchoring member 482 can be a body of various shapes (e.g., straight, spiral, multi-spiral, aggregate, etc.). The external anchoring member 482 is formed of a relatively open structure having the minimum number of segments that can form a structure capable of placing and fixing the occlusion device 480, and minimizes contact with the wall of the blood vessel. Due to the open nature of the external anchoring member 482, the risk of constraining the branch vessels of the blood vessel, that is, the risk of changing the flow of blood flowing through the blood vessel, is small.

[0055] Referring to FIG. 20, an internal anchoring member 494 for an occlusion device 490 according to another exemplary embodiment is illustrated. The internal anchoring member 494 includes a central wire 496 coupled to a cover 492 and one or more outer wires 498 coupled to the central wire 496. The outer wires 498 extend outward from the central wire 496 and contact the inner surface 15 of the aneurysm 10. The internal anchoring member 494 is inserted into the aneurysm 10 by a catheter 30 in a folded (e.g., straight) state. Once deployed into the aneurysm 10, the catheter 30 is withdrawn, the outer wires 498 open outward, at least a portion of the outer wire 298 contacts the inner surface 15, and the cover 492 is placed and stopped at the neck 16.

[0056] Referring to FIG. 21, an exemplary occlusion device 520 is shown. The occlusion device 520 is disposed in or near the neck portion 16 of the aneurysm 10 to interrupt or stop the flow of blood between the blood vessel 12 and the internal space 14 of the aneurysm 10, thereby reducing the likelihood of the aneurysm 10 rupturing. The occlusion device 520 is configured to be a low-profile device and minimizes disruption to surrounding tissues such as blood vessel branches. The occlusion device 520 can be configured to be a biodegradable or bioabsorbable material and can be configured to promote endothelialization.

[0057] The occluding device 520 includes an inner cover 522 disposed within the internal space 14 of the aneurysm 10. The inner cover 522 is disposed to cover the neck portion 16 of the aneurysm 10. The inner cover 522 is formed from a relatively high density mesh, such as a micron mesh, formed by a plurality of wires or fibers joined to each other (e.g., welded, soldered, woven, etc.). In this embodiment, the inner cover 522 is a double layer of mesh. The double layer of mesh is first formed as a mesh sphere. In some embodiments, the mesh sphere is folded within the microcatheter 30 for endovascular delivery to the aneurysm 10. When the cover 522 is released from the microcatheter 30, the push wire 32 holds the upper central portion of the mesh sphere, and as a result, the mesh sphere is released and expands into a hemispherical shape. The double layer cover 522 is formed by the mesh sphere, with the first upper portion of the sphere folded over and into the second lower portion of the sphere, thereby forming a double layer hemispherical shape, and as a result, the inner surface of the inner cover 522 has a concave surface as shown in FIGS. 21-22. Since the expanded shape of the sphere depends on the distance between the upper center of the sphere and the lower center of the sphere, it can be adjusted by moving the wire.

[0058] The occluding device 520, including the inner cover 522, may be deployed within the aneurysm 20 in a similar process as described above with reference to FIGS. 3A-3E. With the distal end 34 of the catheter 30 positioned proximate the neck portion 16 of the aneurysm 10, the push wire 32 is moved within the lumen relative to the catheter 30. The inner cover 522 begins to emerge from the end 34 of the catheter 30 and expands into an expanded configuration within the internal space 14. In one embodiment, the inner cover 522 emerges in the form of a mesh sphere. Next, the catheter 30 and / or the push wire 32 are retracted until the inner cover 522 seats on the inner surface 25 of the aneurysm 10. The double layer of the inner cover 522 is formed by folding the upper portion of the sphere over the bottom, such as by pulling the push wire 32 until the upper portion contacts the lower portion, for example. In other embodiments, the inner cover 522 is already deployed from the catheter 30 in a double layer configuration and does not first appear as a sphere.

[0059] Next, referring to FIG. 22, the occlusion device 520 is shown according to another exemplary embodiment, where the occlusion device 520 further includes an external anchoring mechanism 550. The external anchoring member 550 is coupled to and supports the inner cover 522, reducing the likelihood that the inner cover 522 will move away from the neck portion 16 due to the fluid pressure of the blood within the blood vessel 12. In the illustrated embodiment, the external anchoring mechanism 550 is formed by two or more segments or sections, such as the radial lobes 566 that extend outwardly from the neck portion 16. Each of the lobes 566 may be formed of a single wire coil made of nitinol, polymer, or similar material. Instead of a coil, the lobe 566 may be a solid, substantially flat piece of material extending from the inner cover 522. Each lobe 566 may include a central portion 564 configured to be disposed within the neck portion 16 and a peripheral portion 562 configured to extend beyond the neck portion 16 and contact the wall 13 of the blood vessel 12. The wire coil may be formed to have a narrower portion near the central portion 564 and a wider portion near the peripheral portion 562, similar to an hourglass shape. In some embodiments, as shown in the bottom view of the occlusion device 520 shown in FIG. 23A, the narrower and wider portions each have a uniform diameter. In other embodiments, as shown in the bottom view of the occlusion device 520 shown in FIG. 23B, the diameter of the coil continuously expands between the most central portion and the most peripheral portion. The lobes 566 may take other shapes and sizes in addition to those shown. The occlusion device 520 may have from two to eight lobes 566.

[0060] Referring again to FIG. 22, the lobes 566 of the occlusion device 520 are coupled to the inner cover 522 at an angle 570. In some embodiments, the angle 570 formed between the side surface of the inner cover 522 and the plane of the radial lobe is between 15 degrees and 45 degrees. In this way, the lobe 566 acts as a clip that engages the wall 13 of the blood vessel 12 near the neck portion 16, maintaining the positioning of the occlusion device 520 at the lower portion of the aneurysm 12 near the neck portion 16.

[0061] Referring to FIG. 24, in one exemplary embodiment, an occlusion device 620 having an internal anchoring member 640 disposed within an aneurysm 10 is shown. The internal anchoring member 640 is configured to secure an internal cover 622 within the lower portion of the aneurysm 10 at or near the neck portion 16. The internal anchoring member 640 provides a relatively rigid body to support the internal cover 622 and reduces the likelihood that the internal cover 622 will be displaced from the neck portion 16 by the fluid pressure of the blood within the blood vessel 12. According to an exemplary embodiment, the internal cover 622 is a bilayer formed in the same manner as the internal cover 522. The internal cover 622 has a peripheral portion that contacts the inner surface 15 of the aneurysm 10.

[0062] According to an exemplary embodiment, the internal anchoring member 640 includes one or more windings of a coil formed from a suitable biocompatible metal or alloy (e.g., platinum, stainless steel, nickel-titanium alloy, etc.). The metal coil can be spring-like and can be similar to the coils typically utilized in endovascular coiling procedures. The internal anchoring member 640 is coupled to the internal cover 622 and includes at least one coil that contacts the inner surface 15 of the aneurysm 10. In the illustrated embodiment, the windings of the internal anchoring member 640 do not fill the entire internal space 14 nor a substantial portion of the internal space 14. Instead, the internal anchoring member 640 includes only a single set of windings that extend from the cover 622 like a stem. In some embodiments, the anchoring member 640 can be a soft net coil. In other embodiments, the anchoring member 640 can include a number of windings that substantially fill the internal space 14. The orientation, number, and size of the windings of the internal anchoring member 640 can vary depending on the size and shape of the aneurysm 10.

[0063] Alternatively, the inner covers 622 and 522 can be implemented with any inner anchoring member as described in the present disclosure. Further, although not shown in FIG. 24, the occlusion device 620 can include any of the external anchoring members as described in the present disclosure, including but not limited to the external anchoring members 250, 360, 450, 460, 482, and 550.

[0064] Referring to FIG. 25, in one exemplary embodiment, an occlusion device 720 having an inner anchoring member 740 is shown. The inner anchoring member 740 is configured to fix the inner cover 722 within the lower part of the aneurysm 10 at or near the neck portion 16. The inner anchoring member 740 provides a relatively rigid body to support the inner cover 722, reducing the possibility that the inner cover 722 is displaced from the neck portion 16 by the fluid pressure of the blood within the blood vessel 12. According to an exemplary embodiment, the inner cover 722 is a double layer formed in the same manner as the inner covers 522 and 622. The inner cover 722 has a peripheral portion that contacts the inner surface 15 of the aneurysm 10.

[0065] According to an exemplary embodiment, the inner anchoring member 740 is similar to the inner anchoring member 640 in that it extends from a substantially central portion of the cover 722 like a stem. In this embodiment, unlike the inner anchoring member 640, the inner anchoring member 740 is a cylindrical stem made from a sheet of mesh material. The cylindrical stem can be surrounded at the distal end of the stem that contacts the inner surface 15 of the aneurysm 10. The mesh material can be wound around a set of windings that form a coil or can be self - supporting. The inner anchoring member 740 can include a plurality of folds 742 that form an accordion - like structure that can contract when pressed against the inner surface 15 of the aneurysm 10. In some embodiments, the mesh material is a very fine high - density wire mesh. The mesh material can be a combination of metal and nitinol woven with thread. In some embodiments, the upper end 744 of the inner anchoring member 740 is covered or closed.

[0066] The internal anchoring member 740 of FIG. 25 can be configured as an integral structure with the cover 722. For example, using the same mesh sheet, a cover 722 having an extension portion forming the stem of the internal anchoring member 740 can be formed. In other embodiments, the cover 722 and the internal anchoring member 740 are separate elements that are joined or molded together.

[0067] Although not shown in FIG. 25, the occlusion device 720 can include any of the external anchoring members as described in the present disclosure, including but not limited to the external anchoring members 250, 360, 450, 460, 482, and 550.

[0068] Referring to FIGS. 26A - B, in one exemplary embodiment, an internal cover 822 for an occlusion device is shown. In this embodiment, the internal cover is a multi - layer internal cover 822. The internal cover 822 includes a plurality of leaves 824 that are arranged in an overlapping relationship with each other and are individually movable. The leaves 824 are arranged around the central portion of the internal cover 822. In the side view of FIG. 26A, the internal cover 822 is shown in a partially contracted configuration, and the leaves are positioned closely around the central portion. In FIG. 26B, which is a top view showing the internal cover in an expanded configuration, such as when the internal cover 822 is deployed near the neck 16 of the aneurysm 10, the leaves 824 are expanded or fanned out such that they extend outward from the central portion of the internal cover 822. At least a portion of the leaves 824 of the internal cover 822 are configured to contact the inner surface 15 of the aneurysm 10 when in the expanded configuration.

[0069] According to an exemplary embodiment, the individual leaves 824 of the inner cover 822 are made of a mesh material such as a biocompatible metal or metal alloy, such as platinum, stainless steel, titanium, a titanium-nickel alloy (e.g., nitinol). The leaves 824 of the inner cover 822 may be formed of a relatively high-density mesh, such as a 37-micron mesh, formed by a plurality of wires or fibers that are joined or formed together. The inner cover 822 can be used in combination with an inner anchoring member as described elsewhere herein, including but not limited to the inner anchoring member and central stem described below and shown in FIGS. 27-32.

[0070] Figs. 27-32 each show an occlusion device having a similar overall structure. For example, each embodiment shown therein includes an inner cover (922, 1022, 1122, 1222, 1322, 1422, 1522, 1622) and an inner anchoring member (940, 1040, 1140, 1240, 1340, 1440, 1540, 1640) connected by a central stem (930, 1030, 1130, 1230, 1330, 1430, 1530, 1630). In these embodiments, the inner cover and the inner anchoring member are discs having substantially the same diameter. The central stem can be a cylindrical body having a diameter smaller than the diameters of the inner cover and the inner anchoring member. The inner cover, the inner anchoring member, and the central stem are all composed of mesh material, similar to the occlusion device described above. In some embodiments of FIGS. 27-32, the inner cover is made of a higher-density mesh and the inner anchoring member is made of a lower-density mesh.

[0071] Various configurations and combinations are shown and described with reference to FIGS. 27-32. The present design is not limited to the illustrated embodiments, and it is contemplated that the various features described in FIGS. 27-32 can be used in other combinations and configurations with each other. Further, any of the embodiments shown in FIGS. 27-32 may utilize the multilayer cover 822 shown in FIGS. 26A-26B. The illustrated embodiments may also incorporate any of the external anchoring members, including but not limited to the above external anchoring members (250, 360, 450, 460, 482, and 550).

[0072] Referring to FIG. 27, in one exemplary embodiment, the occlusion device 920 is shown disposed within the aneurysm 10. The occlusion device 920 has an inner cover 922 and an inner anchoring member 940 connected by a central stem 930. The central stem 930 may be a cylindrical body. The inner cover 922 and the inner anchoring member 940 are each generally concave surfaces, the concave surfaces facing towards the stem 930 and facing each other. The inner cover 922, the inner anchoring member 940, and the central stem 930 may be separately configured and joined together. In other embodiments, the three elements are formed from a single sheet and are integral. In this embodiment, both the inner cover 922 and the inner anchoring mechanism 940 are composed of a single layer disc of mesh material.

[0073] Referring to FIG. 28, in one exemplary embodiment, an occlusion device 1020 is shown. The occlusion device 1020 has an inner cover 1022 and an inner anchoring member 1040 connected by a central stem 1030. The inner cover 1022 and the inner anchoring member 1040 are each generally concave, with the concave surfaces facing the stem 1030 and facing each other. The inner cover 1022, the inner anchoring member 1040, and the central stem 1030 may be separately configured and joined together. In other embodiments, the three elements are formed from a single sheet and are integral. The occlusion device 1020 of FIG. 28 differs from the occlusion device 920 in that both the inner cover 1022 and the inner anchoring mechanism 1040 are composed of a double layer of mesh material, and the double layer of mesh material can be formed in the same manner as the inner covers 522, 622, or 722 described above.

[0074] Referring to FIG. 29, in one exemplary embodiment, an occlusion device 1120 is shown. The occlusion device 1120 has an inner cover 1122 and an inner anchoring member 1140 connected by a central stem 1130. The inner cover 1122 and the inner anchoring member 1140 are each generally concave, with the concave surfaces facing the stem 1130 and facing each other. The inner cover 1122, the inner anchoring member 1140, and the central stem 1130 may be separately configured and joined together. In other embodiments, the three elements are formed from a single sheet and are integral. The occlusion device 1120 of FIG. 29 differs from the occlusion device 920 in that the inner cover 1122 is composed of a single layer of mesh material and the inner anchoring mechanism 1140 is composed of a double layer of mesh material, and the double layer of mesh material can be formed in the same manner as the inner covers 522, 622, or 722 described above.

[0075] Referring to FIG. 30, in one exemplary embodiment, an occlusion device 1220 is shown. The occlusion device 1220 has an inner cover 1222 and an inner anchoring member 1240 connected by a central stem 1230. The inner cover 1222 and the inner anchoring member 1240 are each generally concave surfaces, the concave surfaces facing towards the stem 1230 and facing each other. The inner cover 1222, the inner anchoring member 1240, and the central stem 1230 may be separately configured and joined together. In other embodiments, the three elements are formed in a single sheet and are integral. The occlusion device 1220 of FIG. 30 differs from the occlusion device 920 in that the inner anchoring mechanism 1240 is composed of a single layer of mesh material and the inner cover 1222 is composed of a double layer of mesh material, and the double layer of mesh material can be formed in the same manner as the inner covers 522, 622, or 722 described above.

[0076] Referring to FIG. 31, in one exemplary embodiment, an occlusion device 1320 is shown. The occlusion device 1320 has an inner cover 1322 and an inner anchoring member 1340 connected by a central stem 1330. The occlusion device 1320 of FIG. 31 is similar to the occlusion device 1220 of FIG. 30 in that the inner anchoring mechanism 1240 is composed of a single layer of mesh material, the inner cover 1222 is composed of a double layer of mesh material, and the double layer of mesh material can be formed in the same manner as the inner covers 522, 622, or 722 described above. However, in this embodiment, the inner anchoring mechanism 1340 is a single-layer end portion of the central stem 1330 that extends outwardly to form a non-traumatic end 1332 of the stem 1330. The occlusion device may also include an outwardly extending inner cover in addition to the outwardly extending inner anchoring mechanism 1340 shown as part of the occlusion device 1320.

[0077] Figures 32A - 32C show other modified forms of the occlusion device according to an exemplary embodiment. Each of these figures, similar to Figures 27 - 31, shows an occlusion device having an internal cover and an internal anchoring mechanism connected by a central stem. In the embodiments of Figures 32A - 32C, it is shown that the internal cover and the internal anchoring mechanism can have shape variations. For example, the internal cover and / or the internal anchoring mechanism can have a flat, non - curved shape. Alternatively, the internal cover and / or the internal anchoring mechanism may have an inclined or curved shape. In this alternative embodiment, the internal cover and / or the internal anchoring mechanism can have a substantially flat central portion with inclined or raised edges. Figure 28 described above shows an occlusion device 1020 in which both the internal cover 1022 and the internal anchoring member 1040 are inclined or curved. Figure 32A shows an occlusion device 1420 in which both the internal cover 1422 and the internal anchoring member 1440 are straight lines. Figure 32B shows an occlusion device 1520 in which the internal cover 1522 is inclined and the internal anchoring member 1540 is straight. Figure 32C shows an occlusion device 1620 in which the internal cover 1622 is straight and the internal anchoring member 1640 is inclined.

[0078] The structure and arrangement of elements of an aneurysm occlusion device as shown in various exemplary embodiments are merely exemplary. Although only a few embodiments have been described in detail in this disclosure, those skilled in the art considering this disclosure will be able to make many modifications without substantially departing from the novel teachings and advantages of the subject matter described herein (e.g., changes in the size, dimensions, structure, shape, and ratios of various elements, values of parameters, mounting arrangements, use of materials, colors, orientations, etc.). For example, elements shown as integrally formed may be composed of multiple parts or elements, the positions of the elements may be reversed or changed in another way, and the nature or number of individual elements or positions may be altered or varied. It should be noted that the elements and / or assemblies of the system may be constructed from any of a variety of materials that provide sufficient strength, durability, or biocompatibility. Without departing from the scope of the present invention, other substitutions, modifications, changes, and omissions can be made in the design, operating conditions, and arrangements of the preferred and other exemplary embodiments and medical procedures.

Claims

**Claim 1**: An occlusion device detachably disposed on a push wire, wherein the occlusion device comprises a cover configured to be disposed within the internal space of the aneurysm, the cover being configured to cover the neck portion of the aneurysm, the cover being configured to expand from a compressed configuration within the lumen of the catheter to an expanded configuration when advanced outside the distal end of the catheter, the cover comprising an inner layer folded into an outer layer and having a double-layer mesh with a hemispherical shape such that the inner surface of the inner layer of the cover has a concave surface in the expanded configuration, the cover being seated in contact with the inner surface of the aneurysm adjacent to the neck portion of the aneurysm and configured to cover the neck portion of the aneurysm. **Claim 2** The occlusion device according to claim 1, wherein the double-layer mesh comprises an upper portion of the sphere folded into the bottom of the sphere. **Claim 3** The occlusion device according to any one of claims 1 or 2, wherein the double-layer mesh comprises a plurality of wires or fibers. **Claim 4** The occlusion device according to claim 3, wherein the plurality of wires or fibers are woven together. **Claim 5** The occlusion device according to any one of claims 1 to 4, wherein the cover is biased toward the expanded configuration. **Claim 6** The occlusion device according to any one of claims 1 to 5, wherein the cover has a thickness of less than 100 micrometers. **Claim 7** The occlusion device according to any one of claims 1 to 6, wherein the cover in its expanded configuration has a diameter between 5 mm and 12 mm. **Claim 8** The occlusion device according to any one of claims 1 to 7, wherein the cover comprises a biodegradable or bioabsorbable material. **Claim 9** The occlusion device according to claim 8, wherein the biodegradable or bioabsorbable material promotes endothelialization. **Claim 10** The occlusion device according to any one of claims 1 to 9, wherein the double-layer mesh comprises a woven mesh. **Claim 11** The occlusion device according to any one of claims 1 to 10, wherein the cover is detachable from the push wire by electrical disconnection. **Claim 12** The occlusion device according to any one of claims 1 to 10, wherein the cover is detachable from the push wire by mechanical disconnection. **Claim 13** The occlusion device according to any one of claims 1 to 10, wherein the cover is configured to be removed from the push wire by retraction of the push wire within the catheter.

14. The occlusion device according to any one of claims 1 to 13, wherein the cover comprises a metal.

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