Vascular occlusion devices

Abstract

To provide an occlusion device capable of matching a shape to a complicated shape related to a vascular system and quickly occluding a target region.SOLUTION: An occlusion device for medical treatment of a lumen, comprises: a holding part with a closed proximal end formed of a plurality of cylindrically braided wires, where the closed proximal end has a first opening; and a catheter having a tip detachably connected to the holding part, where the catheter has a passageway extending to a distal end of the catheter and aligned with the first opening of the holding part. An embolic material in the passageway of the catheter is advanceable into the cylindrical shape of the holding part through the passageway and the first opening.SELECTED DRAWING: Figure 1

Description

Related Applications

[0001] This application claims priority to U.S. Provisional Application No. 62 / 293,710, entitled "Vascular Occlusion Device," filed February 10, 2016, the entire contents of which are incorporated herein by reference. [Background technology]

[0002] Vascular occlusion is often required in a variety of cases, including, but not limited to, the treatment of aneurysms, atrial septal defects, patent foramen ovale, left atrial appendage occlusion, patent ductus arteriosus, fistulas, arteriovenous malformations, fallopian tube occlusion for infertility, and peripheral vasculature occlusion. One method of vascular occlusion involves filling the blood vessel, malformation, or aneurysm with an occlusion device for the purpose of embolization. Typically, embolic coils are used for this purpose.

[0003] The complex geometries potentially associated with various target regions of the vasculature make successful occlusion difficult, and there is a strong need for occlusion devices that can conform to the complex geometries associated with the vasculature and quickly occlude target regions. Summary of the Invention

[0004] The occlusion device is described below.

[0005] In one embodiment, the occlusion device includes a retention portion and a support portion, hi one embodiment, the retention portion is cloverleaf shaped and the distal support portion is a cylindrical mesh.

[0006] In one embodiment, the occlusion device includes a retention portion and a support portion, and another occlusion device can be used to fill the support portion.

[0007] In one embodiment, the occlusion device includes a retention portion, a support portion, and an attached delivery tube, wherein an additional occlusion device can be delivered via the attached delivery tube to fill the support portion.

[0008] In one embodiment, the occlusive device comprises one or more disc-shaped elements.

[0009] In one embodiment, the occlusive device includes one or more disc-shaped elements and a central element that traverses at least some of the disc-shaped elements.

[0010] In one embodiment, the occlusive device comprises a ribbon shape. In one embodiment, the occlusive device comprises a helical ribbon shape.

[0011] In one embodiment, the occlusion device includes a smaller diameter region and a larger diameter region. In one embodiment, the smaller diameter region and the larger diameter region are arranged in an alternating sequence. In one embodiment, the smaller diameter region utilizes a substantially constant shape and the larger diameter region utilizes a different substantially constant shape.

[0012] In one embodiment, a delivery system for delivering and removing an occlusion device is described.

[0013] In one embodiment, the occlusion device utilizes a stretch resistant member to help control the expansion of the occlusion device during delivery.

[0014] In one embodiment, the occlusion device includes an outer member and an inner member, hi one embodiment, the inner and outer members are constructed from the same braided material that is packed just inside each other.

[0015] In one embodiment, the occlusion device includes one or more sealing members, which may be disposed on at least one of the proximal and / or distal ends of the device.

[0016] In a different embodiment, the occlusive device includes a structural portion and a mesh or membrane portion covering the structural portion.

[0017] In a different embodiment, the occlusion device includes a cervical bridging element and one or more filling structures.

[0018] In a different embodiment, the occlusion device includes a neck bridging element and an embolic material, such as an embolic coil.

[0019] In a different embodiment, the occlusion device includes a plurality of structural struts and a tip contact portion.

[0020] In one different embodiment, the occlusion device includes two separate occlusion sections connected by a coil.

[0021] Additionally, a method for manufacturing the occlusion device is described.

[0022] In one embodiment, the occlusion device is made by taking a central element and attaching one or more wires to the central element to form a retention portion. In one embodiment, the occlusion device is made by taking a central element and threading one or more wires through the central element to form a retention portion. In one embodiment, the retention portion is cloverleaf shaped. A support portion, i.e., a mesh comprising multiple wires in one embodiment, can then be attached to the retention portion.

[0023] In one embodiment, the occlusion device is manufactured by winding the occlusion device over one or more disk-shaped elements, the one or more disk-shaped elements having a plurality of holes through which the constituent wires that make up the occlusion device are inserted and wound. The one or more disk-shaped elements may optionally include a central channel through which the plurality of wires are drawn to form a central element that traverses at least some of the disk-shaped elements.

[0024] In another embodiment, the occlusion device is manufactured by heat setting the device over a mandrel into a shape that includes a smaller diameter region and a larger diameter region. In another embodiment, the occlusion device is manufactured over a mandrel having a relatively constant diameter. Then, multiple marker bands or multiple connecting elements are selectively placed throughout the occlusion device to form the smaller diameter region that covers the entire length of the occlusion device.

[0025] In one alternative embodiment, a braider utilizes both an inner braider and an outer braider to braid the occlusion device, which is wound over one or more mandrels, and the use of both an inner braider and an outer braider can help speed up the manufacturing process.

[0026] In another embodiment, a tapered mandrel can be used in conjunction with a braider to form an occlusion device that includes both an inner region and an outer region.

[0027] In a different embodiment, a removable mandrel can be used to wind the occlusion device.

[0028] In another embodiment, a vertical blider is described that can be used to manufacture an occlusion device.

[0029] In another embodiment, an implant including a closed end is braided over a mandrel utilizing the closed end and a series of pins on the closed end section to assist in forming the closed end. The implant may be an occlusion device.

[0030] In another embodiment, a rotatable bridle is described, which can be used to create an implant with multiple regions of varying stiffness. [Brief explanation of the drawings]

[0031] These and other aspects, features, and advantages of possible embodiments of the present invention will be apparent from and elucidated in the following description of embodiments of the invention and by reference to the accompanying drawings.

[0032] [Figure 1-5] 1-5 show an occlusion device that includes a retention portion and a support portion.

[0033] [Figure 6] FIG. 6 shows an occlusion device that includes multiple retention portions.

[0034] [Figure 7] FIG. 7 shows the manufacturing elements used to form the retaining portion of the occlusion device.

[0035] [Figure 8-12] 8-12 show an occlusion device that includes multiple disk-shaped sections and a mandrel for creating the same.

[0036] [Figure 13-14] 13-14 show an occlusion device that includes a smaller diameter region and a larger diameter region.

[0037] [Figure 15] FIG. 15 shows an occlusion device comprising a helical ribbon.

[0038] [Figure 16-22] 16-22 show various removal systems for implants, where the implant may be an occlusion device.

[0039] [Figure 23] 23A and 23B show an occlusion device having tension members that allow the device to expand in a curved configuration.

[0040] [Figure 24] 24A and 24B disclose an occlusion device extending from its catheter in an offset configuration.

[0041] FIG. 24C shows a mandrel for forming the occlusion device of FIGS. 24A and 24B.

[0042] [Figure 25] 25A-25D show a braided occlusion device having multiple concave end termination points and a mandrel for creating them.

[0043] [Figure 26] 26A-26F show an occlusion device that includes an outer section and an inner section.

[0044] [Figure 27] 27A-27D show an occlusion device that includes a sealing member.

[0045] 27E-27F show an occlusive device that includes a structural portion and a mesh or membrane portion.

[0046] [Figure 28] 28A-28C show a braiding device that includes an inner braiding and an outer braiding.

[0047] [Figure 29] 29A-29E show a tapered mandrel used to form the occlusion device.

[0048] [Figure 30] Figure 30 shows a vertical blider.

[0049] [Figure 31] 31A and 31E show a mandrel used to form an implant with a closed end.

[0050] 31B-31D and 31F show an alternative embodiment of an occlusion device having a braided closed end.

[0051] [Figure 32] 32A-32C show cross sections of a braided structure formed by rotatable braiders.

[0052] [Figure 33] 33A-33E show a detachment system for use with an occlusion device.

[0053] [Figure 34] 34A-34B show a detachment system for use with an occlusion device.

[0054] [Figure 35-40] 35-40 show an occlusion device that includes a cervical bridging element.

[0055] [Figure 41-42] 41-42 show an occlusion device that includes a plurality of struts and a tip contact portion.

[0056] [Figure 43-45]43-45 show an occlusion device that includes a top element, a bottom element, and a coil connecting component. DETAILED DESCRIPTION OF THE INVENTION

[0057] Several specific embodiments of the present invention will be described with reference to the accompanying drawings. However, the present invention may be embodied in several different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those skilled in the art. The terminology used in the detailed description of several embodiments illustrated in the accompanying drawings is not intended to be limiting. In the drawings, like numbers refer to like elements.

[0058] Occlusion and / or embolization devices are described that can be used for a variety of purposes, including, but not limited to, filling aneurysms, atrial septal defects, patent foramen ovale, left atrial appendage occlusion, patent ductus arteriosus, fistulas, arteriovenous malformations, fallopian tube occlusion for infertility, and peripheral vasculature occlusion. Some of the embodiments described herein can be considered intrasaccular devices.

[0059] For purposes of illustrating the use of the embodiments described herein, the treatment of an aneurysm will be described for ease of explanation and consistency, however, various embodiments of the device can be used for numerous purposes in addition to treating an aneurysm, including those described above.

[0060] Typical techniques for treating vascular diseases such as aneurysms utilize coils to fill spaces or clips to block blood flow to the target area. These techniques present challenges when the aneurysm / treatment area has a wide neck or complex shape, as coil placement and retention can be problematic. Intrasaccular devices are intended to create an occlusion at the neck of the aneurysm and conform to the general shape of the aneurysm, thereby restricting blood flow from the neck to the aneurysm and occluding the target site. Examples of such devices can be found in commonly assigned US20140200607, the disclosure of which is incorporated herein by reference in its entirety.

[0061] The intrasaccular devices described herein may also be used with embolic coils, liquid embolic material, or other embolic means to enhance the occlusion effect at the target site. Many embodiments disclosed herein are detachable intrasaccular devices connected to a catheter and allow embolic material to be delivered through the catheter itself. The catheter has a passageway extending along its length and opening into the intrasaccular device. As the intrasaccular device is advanced toward the target aneurysm and expands, embolic means, such as embolic coils or liquid embolic material, are advanced through the catheter and exit the catheter into the intrasaccular device and / or the aneurysm. Finally, the intrasaccular device can be removed from the catheter. Note that the intrasaccular device can be first positioned within the aneurysm to seal the aneurysm from adjacent vessels, followed by delivery of the embolic material. This sequence of procedures allows for better retention of the embolic material within the aneurysm compared to delivering the embolic material first and then the intrasaccular device. The opening in the intrasaccular device may also be used to attach a tether or monofilament that is also connected to the catheter, allowing the intrasaccular device to be removed using a removal mechanism within the catheter.

[0062] One embodiment of such an intrasaccular device 11 can be seen in Figures 1-5. The intrasaccular device 11 includes a plurality of support portions 12 for supporting a plurality of embolic coils 6, and a retaining portion 10 that expands and supports the proximal ends of the support portions 12. As described in more detail below, the intrasaccular device 11 includes an opening that connects to a passageway within the microcatheter 9 to allow for delivery of embolic material after expansion and / or connection of a tether to releasably retain the intrasaccular device 11.

[0063] In one embodiment, support portion 12 is comprised of a plurality of wires woven into a mesh or braided structure, which then expands into a cylindrical or concave disk shape. As best shown in Figures 4A and 4B, the proximal end of support portion 12 terminates in its own mesh with a cylindrical proximal end member 15. This end member 15 preferably includes a passageway 15A (see Figure 4B) connecting the proximal and distal ends of support portion 12.

[0064] In one embodiment, proximal member 15 can be formed by first gathering the proximal ends of the mesh of support portion 12 together and then placing a relatively large radiopaque marker band around the proximal end of the gathered mesh. A smaller marker band is then placed inside the mesh and aligned concentrically with the larger marker band. Finally, the two marker bands are welded together. Because both marker bands are annular or ring-shaped, they form proximal member 15 with passageway 15A extending through both marker bands.

[0065] In another embodiment, all of the braided wires of the mesh of the support portion can be threaded through the center of a radiopaque marker band to form proximal member 15. A mandrel with low weldability (i.e., a mandrel that does not melt easily at normal welding temperatures) is placed within the mesh and marker band, and the mesh and ring are welded together, leaving a passage 15A through the resulting proximal member 15.

[0066] In yet another embodiment, the braided wires of the support portion mesh can be threaded through a tube with poor welding properties to form proximal member 15. A mandrel, also with poor welding properties, is threaded through the inside of the mesh, allowing the wires of the mesh to be welded together. The tube and mandrel are removed from the mesh, leaving a passage 15A through the resulting proximal member 15. Optionally, additional welds can be performed around the outer diameter of the device to increase the strength of end member 15.

[0067] In one alternative embodiment, the size of the proximal member 15 can be reduced by first cutting the proximal end of the initial braided structure of the support portion 12 into multiple pointed or triangular flaps 12A. For example, 4 to 16 flaps can be formed. In one of the techniques described above, the resulting multiple flaps 12A can be twisted together to form the proximal member 15. The reduction in the number of wires holding the end member 15 together can result in an end member 15 that is substantially smaller than if multiple flaps 12A were not formed.

[0068] In one embodiment, the retention portion 10 includes multiple loops 22 formed from one or more wires, and the retention portion 10 extends radially such that the loops 22 are substantially aligned in a single plane. The retention portion 10 includes a central element 18, shown in top and side views in FIGS. 3 and 4, that holds the wires forming the loops 22. The central element includes a central opening or lumen 21 and multiple smaller openings 20. The central opening 21 is preferably connected or aligned with the passage 15A of the support portion 12, thereby forming a continuous pathway between the passage in the catheter 9, the passage 15A, and the opening 21. This continuous pathway allows for the delivery of embolic material into the intrasaccular device 11.

[0069] The wires are threaded through the small openings 20 to form a cloverleaf shape as shown in FIG. 5. Four of these "cloverleaf" loops 22 are shown in FIG. 5, but fewer or more leaves may be used. In one embodiment, each leaf may be formed from a single wire, with one end of the wire positioned to pass through a first hole and the other end of the wire positioned to pass through a second hole. The two ends of the wire are welded or otherwise joined to each other. Thus, each leaf utilizes two holes on the central element 18. FIGS. 3-4 show eight holes used with each of the four leaves. In another embodiment, the central element may not include holes and may instead be simply a single piece to which the cloverleaf wires are attached (by adhesive, mechanical bonding, or welding).

[0070] 7 shows a mandrel or fixture 17 that can be used to form the retainer 10. The fixture 17 includes a slot 17A for receiving a central element 18. Multiple wires can be wound around the "petal"-shaped fixture 17B to form multiple "cloverleaf" loops 22. Optionally, a press 17C can be used to press the device down and hold the shape. Additionally, a subsequent heat treatment procedure can optionally be performed.

[0071] The support element 12 can be attached to the retention portion 10 by adhesive, mechanical bonding, or welding. The support element 12 is positioned across the proximal opposing ends of the plurality of "cloverleaf" loops 22 and then extends like a cylinder with distally projecting walls. While the support element 12 shown in FIG. 1 has an open top, closed tops can also be used. The support element 12 can be constructed from a mesh or braided structure of wire, such as nitinol wire. Radiopaque materials, such as titanium, platinum, gold, and / or palladium, can also be used. In one embodiment, the mesh simply comprises nitinol wire. In another embodiment, the mesh comprises nitinol wire in combination with another radiopaque wire (e.g., a material described above). In another embodiment, a wire with a radiopaque core and a nitinol outer layer, or a nitinol core and a radiopaque outer layer, can be used. As best shown in FIG. 2, the retention portion 10, in one embodiment, is positioned at the neck of the aneurysm, while the support element 12 is positioned inside the aneurysm and bridges the aneurysm.

[0072] The device 11 of FIG. 1 can be placed within a larger delivery catheter 8, within which the device 11 is connected to a smaller microcatheter 9. The microcatheter 9 is either routed through the larger catheter 8 or pre-positioned within the distal end of the delivery catheter 8. The proximal end of the support portion 12 of the device 11 can rest flush with the central element 18 of the retention portion 10, extend proximately beyond the retention portion 10, or terminate approximately flush with either the rear or all of the plurality of "cloverleaf" loops 22. In another embodiment, the wire portions of the plurality of cloverleaf loops 22 extend through openings 20 in the central element 18 (see FIG. 3) and are therefore positioned below the central element 18. This creates a basket shape (in the configuration of FIG. 5, four loops form four wire basket projections), and the proximal end of the mesh support portion 12 is positioned within the basket and is constrained by the basket wires. Alternatively, the wires of the support portion 12 can be attached directly above or below the plurality of cloverleaf loops 22 by adhesive, mechanical bonding, or welding. If this technique is used, the mesh would be configured so as not to block the central opening 21 of the central element 18. The lumen must not be blocked because, as explained below, this lumen can be used to deliver additional embolic material.

[0073] In one embodiment, the occlusion device 11 of FIG. 1 is attached to a microcatheter 9. That is, the microcatheter 9 is connected to a central element 18, a support portion 12, and a retention portion 10 at the tip of the microcatheter 9. The microcatheter 9 is delivered through a larger catheter 8, and the support portion 12 and retention portion 10 assume a collapsed configuration while within the larger catheter 8. In this collapsed configuration, the cloverleaf loops 22 of the retention portion are pressed together (similar to a flower bud before it opens) and positioned beyond the tip of the microcatheter. The support portion is now positioned further distally and is also in a collapsed configuration. The larger delivery catheter 8 is retracted to expose the microcatheter 9 and attached occlusion device 11. Alternatively, the microcatheter 9 is pushed out from the tip of the delivery catheter 8 to expose the device. Once exposed, the support and retention portions assume the expanded configuration shown in FIG. 1. After the occlusion device 11 is positioned within the target treatment site 14, the lumen of the microcatheter 9 can be used to deliver additional embolic material, such as an embolic coil 6 or a liquid embolic material, as best shown in FIG. 2.

[0074] Another embodiment may use only the retention portion 10, without the support portion 12. In such an embodiment, the retention portion is used solely to prevent subsequently delivered embolic coils from falling outward from the neck of the aneurysm 14. Another embodiment may use a retention portion 10 having a mesh layer positioned to completely surround the upper, lower, or both sides of the multiple "cloverleaf" loops 22 of the retention portion 10. The mesh provides an occlusive effect that limits blood flow into the aneurysm (i.e., the mesh itself provides a barrier to blood intrusion). Any additional embolic material subsequently introduced, such as embolic coils or liquid embolic material, then augments the occlusion within the aneurysm / treatment site. For example, after the occlusion device 11 is positioned at the target treatment site and any optional embolic material (i.e., coils, liquid embolic material, or other embolic material) is introduced via the microcatheter 9, the occlusion device 11 is detached from the microcatheter and remains at the treatment site. This allows the microcatheter 9 to be withdrawn.

[0075] A detachment system can be utilized with the central element 18 of the retention element 10. Detachable tip devices for detaching the tip section of a microcatheter are known in the art and are often used with liquid embolic material delivery systems. These devices are detachable to allow withdrawal of the remainder of the catheter when the tip section of the catheter becomes stuck or "glued" to the delivered liquid embolic material. A detachable tip can be used with the central element 18, resulting in a microcatheter having a central element 16 and a retention element 10 constructed on the distal end of the microcatheter. Electrolytic, thermal, or mechanical detachment systems can be used to separate the central element from the microcatheter, leaving the occlusion device at the target treatment site. Alternatively, the detachment contact can be located proximal to the central element. For example, the detachable tip element can be connected to the central element 16 but positioned proximal to the central element. U.S. Patent Publication No. 2015 / 0137773 discloses several detachable tip system embodiments that can be used in the present embodiment, and the entire disclosure of U.S. Patent Publication No. 2015 / 0137773 is incorporated herein by reference.

[0076] 33A-33E illustrate a unique detachment system 107 that can be used with the occlusion device 11 shown in FIG. 1 , as well as any of the other occlusion devices described herein. Unlike other detachment systems in the prior art, the embodiment of FIGS. 33A-33E illustrates a detachment system that can accommodate a central opening in the lumen 21 (best shown in FIG. 3). One embodiment of the device 107 utilizes an occlusion device connected to the tip of a relatively small microcatheter or delivery tube 106, which is itself delivered through a separate, relatively larger catheter. The detachment system 107 allows the microcatheter or delivery tube 106 connected to the occlusion device 11 to be detached from the occlusion device 11 at the appropriate time. For example, the occlusion device 11 can be positioned within an aneurysm, the attached microcatheter 106 used to deliver additional embolic material (e.g., liquid embolic material or coils), and then the microcatheter 106 can be detached and removed, leaving the occlusion device 11 in place. The detachment system 107 utilizes a heater 104 within the distal region of the attached microcatheter 106. The heater 104 is an electrically resistive wire coil or laser-cut sheet in various patterns (e.g., the square wave pattern shown in the drawings). Wires 108a and 108b are connected to the heater 104 at two locations and are supplied with a voltage source at the proximal end of the device 107 so that each wire is oppositely polarized, allowing the heater 104 to carry electrical current. A cylindrical cover 110 is positioned over the heater 104, and a sacrificial polymer or adhesive layer can be positioned between the cover 110 and the heater 104. The operating principle is that heat generated by the heater 104 separates the sacrificial layer, detaching the microcatheter 106 from the cover 110, thereby leaving the microcatheter behind without retracting it from the vasculature, as shown in Figures 33D and 33E.

[0077] FIG. 33A shows an embodiment in which both the sacrificial polymer or adhesive layer and the heater extend more than 180 degrees but less than 360 degrees around the opening or lumen. Various configurations are possible. For example, the inner sacrificial polymer or adhesive layer, which is melted by the heater, may extend in discontinuous segments that selectively wrap around the opening. The heater and sacrificial layer may extend to completely or nearly completely surround the opening. One of the heater or sacrificial layer may extend completely around the opening, while the other may extend less than completely. The sacrificial layer preferably extends to completely surround the opening by at least 180 degrees, while the heater should cover at least the width of the sacrificial layer.

[0078] 1 and the detachment system 107 of FIGS. 33A-33E include taking the occlusion device 11 with the attached microcatheter 106 and delivering the system through a larger catheter. Once the occlusion device 11 is properly positioned, additional embolic material is optionally delivered through the attached microcatheter 106, after which a detachment sequence is initiated in which the microcatheter 106 is detached from the occlusion device 11, followed by withdrawal of the microcatheter 106.

[0079] 34A and 34B illustrate an occlusion device removal system 150 that can be used with occlusion device 11, as well as any of the other occlusion devices described herein. As shown in FIG. 34B, system 150 uses a device coupling ring 152 on the proximal end of the occlusion device and two tethers 159 attached to a tubular pusher 156. Each tether 158 is connected to a selectively activated power source and is surrounded by a heater coil 158 that, when activated, raises the temperature and breaks tether 159, detaching device coupling ring 152 and the occlusion device connected thereto.

[0080] The heater coil 158 is preferably disposed within two opposing channels cut into the tubular press body 156. Each channel within the heater coil 158 is aligned with an opening 154A through the press coupling ring 154. Similarly, the device coupling ring 152 has two openings 152A that face or oppose each other and are aligned with the openings 154A. A tether 159 passes through the opening 152A and is bonded or secured to the proximal side of the opening 152A through the opening 154A and the heater coil 158, and is further bonded / secured proximally to the heater coil 158 within the slot 156A.

[0081] If the occlusion device comprises a braided structure or mesh, similar to device 11, it is attached to device coupling ring 152 by first feeding the mesh through the main opening of ring 152 and then placing an inner mandrel, matching the size of the central lumen of push tube 156, within the center of the captured mesh. The ends of the mesh are then welded to ring 152 and the mandrel is removed, leaving a passageway within the occlusion device. The main opening of push coupling ring 154 is sized and positioned to cover the end of push tube 156, so that the central lumen of push tube 156 is aligned with the passageway formed by device coupling ring 152 and the mesh of the occlusion device. This allows embolic material to be advanced through the central push lumen and the occlusion device before the occlusion device is removed.

[0082] As shown in Figure 6, multiple retention portions 10 can be used, with a more proximal retention portion 13b positioned at the neck of the aneurysm and a distal retention portion 13a positioned within the aneurysm. This embodiment can also be used with the support element 12 of Figure 1, with the distal retention portion 10b positioned at the proximal end of the support element 12. Detachment of retention portion 13b is accomplished using the heating techniques described above.

[0083] 8-12 relate to several embodiments of occlusion devices comprised of a braided structure forming multiple disc-shaped sections 31, such as device 30a of FIG. 9, which has a four-disc shape. Although the term "disc-shaped" is used, the shaped sections may take on numerous shapes, such as elliptical, oval, cylindrical, conical, frusto-conical, etc. The purpose of such shapes is to allow for both compressibility and extensibility of the occlusion device.

[0084] This shape is formed by a plurality of winding mandrels 26 having the shape of the desired braided section 31. FIG. 8 shows one embodiment of two disk-shaped mandrels 26 connected to one another by struts 24 extending therethrough. Each mandrel 26 has a plurality of holes 28 into which pins 23 can be inserted to form the desired braid pattern. A portion of the pins 23 are located outside the holes 29, and the braided structure can be wound around the various pins to form the occlusion device shape. Each mandrel 26 can have the same shape, each mandrel 26 can have a different shape, or combinations of similar and different shapes can be used for multiple mandrels 26.

[0085] FIG. 10 shows an embodiment of an occlusion device 33 similar to device 30a of FIG. 9 but with a central braided element 32. The shaped mandrel 26 of FIG. 8 includes a central strut 24. Once the wires are wound through the upper mandrel to form the top of the occlusion device, the remaining portions of the wires are pulled out from the bottom of the central element and central strut 24. Alternatively, if the central element 24 is a rod and does not have a lumen, the remaining portions of the wires are pulled around, but not through, the central element 24. Alternatively, the component wires are first pulled through or around the central rod 24, and then winding of the mandrel begins. Various winding techniques can be used. For example, if three disk-shaped elements 31 are used as shown in Figure 10, the process begins by winding wire first around the center mandrel 26, then the lower mandrel 26, then pulling wire back up over the mandrels, and then winding wire over the upper mandrel 26. This allows the sidewalls to double over a portion of the mesh device as the wires are pulled back over the device, creating a multi-layer effect. Figures 9-12 show an occlusion device including three or four shaped sections 31, although fewer or more shaped sections 31 can be used.

[0086] Other occlusion device configurations may utilize a central element throughout, rather than only a portion of, the braided structure. Various occlusion configurations utilizing fewer or more disk-shaped elements are possible. Figure 11 illustrates different configurations of occlusion device 35 utilizing various elements 31 of different shapes and a central element that extends through only a portion of the occlusion device. In one embodiment, the proximal ends of multiple wires are welded or attached to the proximal end of central element 32 so that the proximal end of the occlusion device is integral.

[0087] Figure 12 shows the device 33 of Figure 10 within an aneurysm 14. As mentioned above, one advantage of utilizing a mesh and having multiple disc-shaped elements of different shapes is the compressibility and extensibility of the braided structure. The braided structure is extensible, and further allows for a reduction in the radial dimension of the disc elements, and is rapidly compressible and expandable at the expense of longitudinal elongation.

[0088] In one embodiment, a winding method for winding the occlusion device of FIGS. 8-12 is described and shown in FIGS. 28A-28E. The winding method is useful for forming devices similar to those shown in FIGS. 10-12, which utilize a central braided element 32 within the disk portion 31. The winding process utilizes two braiding mechanisms: an outer braider 84 and an inner braider 86. A first set of wires 80 is connected to the outer braider 84, and these wires 80 are wound over the pins of the mandrel 26A. A second set of wires 82 is connected to the inner braider 86, and these wires are not braided over the pins, but instead are drawn into the central channel of the mandrel (i.e., element 24 of FIG. 8). The wires 82 are then placed over the outer braider 84.

[0089] The second mandrel 26B is positioned adjacent to the first mandrel 26A. A first set of wires 80 is drawn through the inner channels of the second mandrel 26b (similar to how wires 82 were initially drawn through the inner channels of the first mandrel 26a), while a second set of wires 82 is wound over the pins of the second mandrel. The first set of wires 80 is connected to the inner braid. As will be appreciated, as a set of wires is drawn through the inner channels of the mandrel, it is connected to the inner braid, while as a set of wires is wound over the pins of the mandrel, it is connected to the outer braid. The braider includes multiple carriers 86, which contain multiple bobbins for storing the wires. The braider is automated so that the carriers rotate in various configurations while the mandrel moves longitudinally, allowing for braiding to occur. Additional mandrels may also be placed, with the wire placement alternating sequentially. So, for example, a first set of wires 80 may first form an outer braided structure around a first mandrel, then an inner braided structure in a second mandrel, then an outer braided structure for a third mandrel, while a second set of wires 82 may form an inner braided structure for the first mandrel, then an outer braided structure for the second mandrel, then an inner braided structure for the third mandrel, etc. Because different wire elements form different portions of the outer braided structure and different locations of the outer braided structure, the inner braided structure 32 of this described winding method can be considered non-continuous.Because all wires (of both wire sets 80, 82) must be held by the outer braided structure in some places, the outer braided structure will need more carriers to hold the various wires, while the inner braided structure will only need to hold wire sets 80, 82 (or neither), resulting in the outer braided structure 84 needing at least twice as many carriers as the inner braided structure 86. For example, if the braided structure for each section is comprised of 48 wires (i.e., each wire set 80 and 82 contains 48 wires, for a total of 96 wires), the inner braided structure will need to have at least 48 carriers to house one of the wire sets, while the outer braided structure will need to have at least 96 carriers to house both wire sets.

[0090] 28A-28C illustrate various manufacturing steps just described. A number of different winding methods may also be used with the continuous inner element 32, such as winding a second set of wires 82 through the inner channels of a series of mandrels while winding a first set of wires 80 around the circumference of the various mandrels. When inner and outer braiders are used in this configuration, the second set of wires 82 comprising the continuous inner element 32 remains connected to the inner braider during the braiding operation, while the first set of wires 80 comprising the outer braided portion remains connected to the outer braider.

[0091] Figures 29A-29E show another method for forming a braided structure having multiple layers. A tapered mandrel 88 is braided by a braider 90. The taper allows one end to have a smaller diameter and the other a larger diameter, with the diameter varying between the two ends. For reasons discussed below, it is desirable to have a portion of the smaller diameter end 88a have a constant diameter, as shown in Figure 29C. The tapered mandrel is braided. Circular elements 92 can be placed at one or more locations along the smaller, constant diameter portion 88a of the tapered mandrel. The remaining portion of the braided structure is then folded over the circular element to form an outer spherical shape, while portion 88a remains intact, comprising the inner braided portion. In Figure 29E, three circular elements are placed along section 88a to form three enlarged sections. The folded sections can be bonded and heat-set to set the shape.

[0092] 13A and 13B show an occlusion device 37 comprising a tubular braided structure that is flattened into a double layer and then heat-formed to form a series of narrow mesh regions 39 and wider regions 30b (i.e., multiple "petal" shapes 30b). These petal shapes 30b can be heat-set twice to achieve a curved shape that roughly matches the curvature inside the aneurysm.

[0093] When the initial tubular braided structure is woven with a uniform braid pattern, the braid density is greatest in the narrow regions 39 and lowest in the center of each petal 30b. However, the center of the petals 30b is where the device 37 attempts to create the greatest flow obstruction within the aneurysm, and such braid density does not optimally obstruct flow as intended. Figure 14 illustrates a braiding technique and pattern in which both the pitch and width of the braided structure are varied, thereby providing regions of increased braid density 41 in the centers of the petals 30b and regions of decreased braid density 43 between the centers of multiple petals 30b. This variable pitch / width technique allows for optimization of the braid density for the most effective flow obstruction where the petals are wider, where it is most needed.

[0094] Braiding fixture 35A can be used to create variable pitch / width in the braided structure. Fixture 35A is a valve structure with regularly increasing and decreasing diameters, creating a repeating three-dimensional wave pattern. Fixture 35A also has multiple attachment points for regularly spaced pins 35B surrounding fixture 35A, which allow one or more wires to be braided around fixture 35A. The longitudinal spacing of pins 35B is smallest at each wave peak in region 41, gradually increases toward the wave trough in region 43, and then increases again toward the wave peak. The pore size of the braided pattern is smallest at each wave peak and largest at the wave trough.

[0095] FIG. 15 illustrates an occlusion device 34 including a spiral ribbon mesh. The spiral ribbon may have a uniform or variable diameter / thickness. The support element 12 of FIG. 1 and the occlusion devices of FIGS. 9-15 utilize a braided wire structure or mesh. The wires may be made of nitinol, cobalt-chromium, polymer, stainless steel, and / or spring-tempered stainless steel. Radiopaque materials such as tantalum, palladium, gold, and / or palladium may also be used alternatively and may be incorporated into the mesh along with the radiopaque materials listed in the previous sentence. In one embodiment, the mesh may include only nitinol wires, or in another embodiment, the mesh may include a mesh of nitinol wires with other radiopaque wires (of the materials listed above) comprising the mesh. In another embodiment, wires with a radiopaque core and a nitinol outer layer, or a radiopaque core and a nitinol outer layer, may be used. In one embodiment, the wire diameter may be from about 0.002" to about 0.005". Additionally, some or all of the wires comprising the braided structure / mesh may include radiopaque (i.e., tantalum) coils to aid in visualization.

[0096] The device 11 of FIG. 1 may utilize a detachable tip-type system as previously described, since the occlusion device in this figure is attached to the tip of a microcatheter 9 that is delivered through a larger catheter 8. A different embodiment may instead utilize a solid lumen pusher. The device can be delivered as described above, yet eliminates the need for a microcatheter lumen for subsequent introduction of embolic material. Thus, for example, the occlusion device 11 of FIG. 1 may be connected to a push rod that is pushed through a delivery catheter or microcatheter and placed inside the aneurysm, and the device is subsequently pushed out or the catheter is retracted to expose the device. Thermal, mechanical, or electrolytic detachment systems may be used to detach the central element 16 of the device from the push rod. Various detachment systems are discussed in US5895385, US5108407, US6500149, US4346712, US8182506, US20100268204, US20110301686, and US20150289879, the entire disclosures of all of which are incorporated herein by reference. The push rod and catheter are then retracted. Alternatively, the lumen of the catheter is subsequently used to introduce other embolic material (e.g., coils or liquid embolic material) into the proximally placed occlusion device. Thus, the occlusion device forms a distal barrier that protects the dome of the aneurysm from impact, and additional embolic material fills the more proximal sections of the aneurysm.

[0097] In one embodiment utilizing the device of FIG. 1 connected to a push rod instead of a microcatheter, a first catheter can be used to deploy the occlusion device. A smaller catheter, specifically used for embolic material, can then be placed within the catheter and further placed through the occlusion device to introduce additional embolic material (i.e., embolic coils or liquid embolic material). The occlusion device can then be removed. Alternatively, the occlusion device can be deployed and removed. The catheter initially used to deliver the occlusion device can then be used to deliver additional embolic material (i.e., coils or liquid embolic material). In other cases (such as when a separate catheter is used or when the same occlusion device is reused), the catheter can be guided to a different location within the braided structure to deliver additional embolic material. In one example, the catheter can be positioned toward the top of the occlusion device near the dome of the aneurysm, allowing the aneurysm and occlusion device to fill from bottom to top. In another embodiment, the catheter can be placed toward the bottom of the occlusion device, causing the aneurysm and occlusion device to fill from bottom to top.

[0098] The disk-shaped element of Figures 8-12, the small / large diameter region of Figures 13-14, or the spiral ribbon-shaped device of Figure 15 would be connected to the pusher element. A variety of thermal, mechanical, or electrolytic detachment systems can be used to detach the device from the pusher element, including the detachment systems discussed in the previously incorporated-by-reference applications. Similarly, a catheter used to deliver an occlusion device may subsequently be used to deliver additional embolic material, such as an embolic coil or liquid embolic material.

[0099] 16-22 show a pusher detachment system 45 located near the distal end of an elongated pusher device 47. The pusher 47 is advanced through the catheter 8, and the detachment system 47 is actuated to detach an occlusion device 48, such as the devices 48 described herein. The occlusion device 48 is secured to the pusher by an axially movable detachment wire 38 on the pusher. That is, the occlusion device 48 is initially positioned within a cavity in the connection fixture 40 proximal to the device 48, preventing the device 49 from moving laterally from the proximal end of the pusher 47. A tether connected to the connection fixture 40 and to the more proximal portion of the detachment wire 38 exposed through a cutout region 44 on the distal region of the pusher 36 prevents the device 48 from moving off the detachment wire 38. To improve flexibility and further improve connectivity between the pusher 36 and the connection fixture 40, a spring 42 is positioned between the two.

[0100] To activate the detachment system 45, the detachment wire 38 is retracted proximally so that the distal end of the wire 38 moves proximally, toward the release region 44, and past the proximal point of attachment of the tether 46. The tether is connected to the detachment wire 38 (e.g., connected by a loose knot or a loop fastener) so that the tether slides relative to the detachment wire 38. Thus, not only does the detachment wire 38 move out of the coupling fastener 40, but it also retracts to allow the tether 46 to slide completely off the wire 38, leaving the occlusion device 48 fully disconnected from the pusher 47. Additionally, the spring 42 abuts the coupling fastener 40, providing some force or kick to move the occlusion device 48 away from the pusher 47.

[0101] 17-20 illustrate one possible mechanism by which the proximal end of the pusher body 36 can be broken, exposing the proximal portion of the wire 38, thereby retracting the detachment wire 38 of the pusher tool 47, allowing the physician to proximally retract the wire 38 and activate the detachment system 45. As shown in FIG. 17, the proximal end of the pusher body 36 preferably includes a frangible region 52 (e.g., one or more holes in the pusher body 36) and a visual guide 50 that indicates to the user where to align the breaking tool 54 and assists in breaking the pusher body 36. Preferably, the frangible region 52 of the pusher body 36 is strong enough that it generally will not break during the procedure without the leverage provided by the tool 54, thereby preventing the difficult situation of unintentional removal of the occlusion device 48.

[0102] The breaking tool 54 preferably has a channel sized approximately the same diameter as the proximal end of the pusher body 36, allowing the tool 54 to slide over the pusher body 36. The tool 54 preferably has a relatively small diameter and includes a narrow region 56 aligned with the frangible region 52, allowing the physician to apply additional force to the frangible region 52 and break both the pusher body 36 and the tool 54 itself, as shown in FIGS. 19 and 20 . To facilitate the physician's proper alignment of the narrow region 56, the pusher body 36 preferably includes a window that allows the user to view and align the visual guide 50, as shown in FIG. 18 . Alternatively, the guide may be configured so that the tool 54 must be quickly moved adjacent to the guide, or may be configured as a tactile detent, thereby eliminating the need for a window.

[0103] 21-22 illustrate several alternative embodiments of the detachment system 45 of FIG. 16. FIG. 21 illustrates a detachment system 53 similar to system 45 but without the use of a spring 42 to provide additional kick to push the coupler 40. FIG. 22 uses two windows cut into the coupler fixture 40 and two tethers 46A and 46B. One tether 46A is attached to the distal end of the detachment wire 38 and has a loop that surrounds the distal end of the pusher body 36. The other tether connects to the other proximal section of the detachment wire 38 and also connects to a section of the loop that surrounds the proximal end of the pusher body 36. In both systems, the knot around the detachment wire 36 is loose, so that pulling on the detachment wire releases the coupler fixture 40 and implant 48.

[0104] The occlusion device embodiments of Figures 8-12 and 13-15 may also be configured to operate similarly to the embodiment of Figure 1. That is, the occlusion device may be preloaded onto the tip of a microcatheter that is delivered through a larger catheter. In a different embodiment, the proximal end of the occlusion device utilizes an element similar to central element 16 of Figure 1. The central element would constrain the constituent braided wires together. The central element would be located near the tip of the microcatheter, and a detachable tip system similar to the detachable tip system referenced above would be utilized in this system. As with the embodiment of Figure 1, the user would position the device at the neck of the aneurysm and, optionally, deliver embolic material (i.e., embolic coils or liquid embolic material) through the microcatheter and occlusion device. Once the embolic material has been delivered, the user would detach the tip of the microcatheter and retract the microcatheter via the detachment concept described above.

[0105] Intrasaccular braided devices work very well in bifurcated aneurysms, where a delivery catheter can be passed relatively straight through the aneurysm. However, in other aneurysms, such as sidewall aneurysms, the delivery catheter is positioned more perpendicular to the entrance of the aneurysm neck, making placement of a braided intrasaccular device more difficult. If an intrasaccular device is placed at an angle, the attached pusher and the relatively rigid nature of the device will force the catheter to straighten, further resulting in an angled placement of the device within the aneurysm.

[0106] 23A-23B illustrate a tensioning system 59 that allows the occlusion device 64 to expand in an offset or curved configuration, thereby avoiding the difficulties discussed above. Specifically, the tensioning system 59 includes a tether 58 connected to the distal and proximal ends of the braided occlusion device 64. When the pusher 60 pushes the occlusion device out of the catheter 8, the material of the tether 58 causes the device 64 to maintain tension on one side of the device 64 while expanding, allowing maximum expansion on the opposite side. This allows the device 64 to bend or fold in the direction of the tether 58 while expanding.

[0107] A more controlled, curved delivery maximizes the chances that the occlusion device 64 will assume its expanded shape and fill the aneurysm when the catheter cannot access the aneurysm in a relatively straight trajectory. The tensioning member maintains tension on the occlusion device connections, thereby limiting expansion along one side of the device 64 and allowing it to form a curved shape. Additionally, an advantage of this technology is that the tether 58 can be applied to a wide variety of occlusion device 64 knitting patterns, such as 1-over-1, 2-over-1, and 2-over-2 patterns.

[0108] The tether 58 can be an elastic polymer, elongated nitinol or stainless steel, a coil spring, nitinol or stainless steel wire, a shape memory wire or ribbon, or a platinum or tantalum wire or strip. Additionally, more than one tether can be used, i.e., multiple tethers can be connected in a longitudinal series or offset along the vertical dimension of the implant. In one embodiment, the tether is a nitinol coil or wire, and a heat source is connected to the tether to change the stiffness properties of the tether.

[0109] Figures 24A and 24B show a braided mesh occlusion device 160 that is braided such that the expanded mesh configuration expands in an offset manner relative to the catheter 8 (or pusher), thereby allowing for more optimal expansion within the aneurysm when approached at an angle by the catheter 8, as shown in Figure 24B. In other words, when the device 160 expands, its central axis is offset from the central axis of the catheter 8 from which it expands.

[0110] Such an offset expanding occlusion device 160 can be formed by placing a braided mesh tube or surrounding structure on a mandrel 162 (FIG. 24C) having a relatively large diameter cylindrical structure 162A and a relatively small diameter cylindrical shape 162B. The small diameter cylindrical structure 162B is fixed at a position offset from the central axis of the large diameter cylindrical structure 162A, thereby achieving the offset shape of the occlusion device 160 after heat setting. Preferably, the braided mesh tube is first formed to form a uniform cylinder or tube and then heat set to the offset shape. This technique allows for more consistent braided cell size in the final occlusion device 160. Additionally, an advantage of this technique is that the offset heat set shape can be applied to a wide variety of occlusion device 160 knitting patterns, such as 1-over-1, 2-over-1, and 2-over-2 knitting patterns.

[0111] Additionally, mandrel 162 may include a recess machined into the end of larger diameter cylindrical structure 162A surrounding the mating surface of smaller diameter cylindrical structure 162B to allow the cylinder to be threaded over smaller diameter cylindrical structure 162B and to provide a recessed or depressed area surrounding the proximal end of occlusion device 162. This recess is described in more detail with reference to Figures 25A-25D.

[0112] The braided intrasaccular occlusion devices described herein may be terminated at their proximal and, optionally, distal ends by marker bands or other welding techniques, as described elsewhere herein. However, it is generally undesirable for the termination region to protrude beyond the braided end face at either the proximal or distal ends of the occlusion device. For example, a protruding proximal termination point could extend into the patient's artery and potentially cause unwanted thrombus formation. Additionally, a protruding proximal termination point could potentially rupture the dome of the aneurysm.

[0113] Figures 25A-25D alleviate this difficulty by reducing the outward projection of the braid termination points when in the expanded configuration. Specifically, Figure 25A discloses a distal open-ended occlusion device 170 having a proximal braid termination point 170A that is inwardly concave when expanded. Similarly, Figure 25B shows an enclosed occlusion device 172 having a distal braid termination point 172A and a proximal braid termination point 172B, both of which are inwardly concave when expanded.

[0114] As shown in Figures 25C and 25D, a mandrel 174 having a larger cylindrical portion 174A and a smaller, adjacent cylindrical portion 174B can be used to form an inwardly recessed braided termination point. The larger cylindrical portion 174A has a recess 174C machined into its end, with a diameter that allows the smaller cylindrical portion 174B to be placed inside. The recess is preferably curved or concave, so that the smaller cylindrical portion 174B is exposed even when it is inside. The braided structure of the occlusion device is first placed over both cylindrical portions 174A and 174B, and then a tube 176 is moved over the portion of the braided structure on the smaller cylindrical portion 174B and pressed against the recess 174C. A clip 177 is used to hold the tube 176 in place. This action forces the braided structure into recess 174C, allowing mandrel 174 to be placed in an oven and heat set to achieve the desired recess shape. While mandrel 174 is shown with one recessed end 174C and one smaller cylindrical portion 174A, both ends of larger cylindrical portion 174A can be provided with these features to form an occlusion device 172 with both proximal and distal recessed ends.

[0115] 31A-31B show another embodiment of a braided occlusion device 101 having fully braided ends (or both ends) that alleviate the difficulties associated with protruding proximal or distal ends. In other words, instead of welding or other techniques to close the ends of a cylindrically braided structure, one or more ends are braided closed such that no wires terminate at the ends of the device 101. In one embodiment, the device 101 comprises a cylindrical body having at least one end that terminates in a plurality of loops 101A interconnected to one another and arranged in a circular pattern surrounding the axis of the device 101, such that the end does not include any free ends of the underlying wires of the braided structure.

[0116] The device 101 can be braided onto a mandrel 102 (shown in end views in FIGS. 31A and 31E) having a desired body shape (e.g., cylindrical) and domed or concave ends (both ends, if desired). Alternatively, both ends of the mandrel may have a relatively flat shape with multiple pins. The mandrel 102 has multiple pins 102A protruding from it that allow the user to wind or braid wire in the desired braid pattern around the end of the mandrel 102. A typical braiding technique used with a pre-woven cylindrical section involves starting the braid inward toward the central axis of the device with a second set of wire. This results in free ends of the wire at the edge of the cylindrical section or at the center of the end of the device.

[0117] The braiding pattern of device 101 begins at the center of the end of mandrel 102. Instead of initiating braiding at this location with the free ends of each of the wires, braiding begins substantially away from one of the free ends of each of the wires, thereby ensuring that each end of each wire has sufficient length to complete the braided structure that descends toward the distal end of the occlusion device. Braiding begins with each of the wire-formed loops 101A formed in a circular pattern surrounding the central axis of device 101. To help hold this proximal end together, each of the loops 101A is braided so that at least two adjacent loops interweave with each other. When only two loops interweave with each other (i.e., folded left and right), the loops 101A form a circular pattern with a central opening, as shown in FIGS. 31B and 31C. When loops 101A interweave with loops 101A on diagonal or opposite sides of the circular pattern, device 101 has substantially no central opening, as shown in FIG. 31D. Furthermore, larger loop 101A sizes result in larger potential central openings (FIG. 31C), and smaller loop 101A sizes result in smaller potential central openings (FIG. 31D). Note that the proximal end of device 101 can be woven over mandrel 102 with or without an axial central opening (as described with other embodiments herein and used for delivery embolic devices).

[0118] After the desired braiding is performed, the mandrel 102 and device 101 can be heat set to hold the device configuration on the mandrel 102. The braided end of device 101 can be connected to a pusher or catheter via a tether 101B that is bonded or looped through a portion of the end, and can be made detachable by one of the detachment mechanisms described elsewhere herein (FIG. 31F).

[0119] Figures 31C and 31D show two alternating knit patterns for the ends of the occlusion device. Figure 31C terminates with multiple interconnected circular loops arranged in a circular fashion to leave the device open at its center or axial point. Figure 31D terminates with multiple oval interconnected loops arranged to cover the device's center or axial point, thereby closing the center of the end of the device.

[0120] Figures 26A-26F show several different designs for intravesical devices, many of which include multiple folded elements incorporated into the knitting pattern. The devices shown in these figures are fabricated and heat-set into a configuration, allowing the various elements to fold over one another to form the braided device. During delivery, the device assumes an elongated, unfolded configuration in which all elements are arranged flat and linearly. Upon removal from the delivery catheter, the braided structure then assumes its folded configuration as the various layers sequentially apply pressure within the previously arranged layers. This folding effect is particularly useful for occlusion purposes, as it compresses the braided structure and further increases the occlusion density of the mesh. Alternatively, the elongated delivery configuration of the device may also be elongated compared to the final deployed configuration, utilizing the same elongated folded configuration. In one embodiment, the tip of the braided structure can utilize a longer stem so that the stem pushes against the dome of the aneurysm, expanding it, thereby providing a soft tip cap that the remainder of the braided structure contacts and fills the remainder of the aneurysm.

[0121] FIG. 27A illustrates a sealing device 69 that can be used with an occlusion device 66, such as those described herein. The sealing device 69 includes a concave sealing portion 70 that is connected to the occlusion device 66 by a connecting member 68. The sealing device 69 can be delivered to the distal end of the device and / or the proximal end of the device 66. When placed at the distal end of the device 66, the sealing device 69 contacts the dome of the aneurysm, providing a distal scaffolding against which the remainder of the mesh occlusion device 66 can fill the remainder of the aneurysm. When placed at the proximal end of the device, the sealing device 69 seals the neck of the aneurysm, preventing the occlusion device from being deployed outside the aneurysm. Additionally, if an embolic device (i.e., embolic coils or liquid embolic material) is deployed following the intrasaccular device, the proximal sealing device 69 provides a capture-type element that prevents the embolic material from escaping the aneurysm. In one embodiment, the sealing element is comprised of an umbrella-shaped series of wires, optionally utilizing a membrane covering multiple wires. When sealing device 69 is connected to occlusion device 66 within the aneurysm, connecting member 68 has a plurality of hooks or other engaging members that can engage with occlusion device 66 during subsequent delivery. However, sealing device 69 can also be connected to occlusion device 66 prior to delivery, and thus connecting member 68 can also include adhesive, welding, or other engaging mechanisms.

[0122] FIG. 27B shows proximal and distal sealing devices 69 used in a similar arrangement to occlusion device 72 formed into three folded layers of braided mesh. Connecting members 68 are connected to inner filling member 71 and are further positioned within the multiple layers of occlusion device 72, thereby augmenting the occlusion of the device. FIG. 27C shows a similar arrangement to that of FIG. 27B, except without the use of inner filling member 71. Filling structure 17 can take the form of a wire, hypotube, or sheet cut structure. To facilitate occlusion of the target area, filling structure 17 can be formed into numerous configurations, such as straight, wavy, sinusoidal, and / or coiled. In one embodiment, the filling structure may be made from nitinol wire having a diameter of about 0.002" to about 0.005". Other embodiments may utilize shape-setting polymers, cobalt-chromium, and spring-tempered stainless steel. In one embodiment, each wire includes a tantalum coil for imaging, wrapped around the wire and extending over the entire wire or a sufficient length of the wire to allow visualization of the device during the procedure.

[0123] 27d shows the wire substructure of sealing device 69 without its mesh or membrane covering as it is delivered from a catheter. During delivery, sealing device 69 will assume a straight, elongated shape when collapsed within the aneurysm, and then expand to assume an umbrella shape when removed.

[0124] This sealing concept may be useful in other embodiments. For example, a neck bridging element may utilize a proximal sealing device to occlude the neck of the aneurysm, after which another embolic material (e.g., coils or liquid embolic material) is placed inside the aneurysm and received by the sealing device. In Figures 27E and 27F, the occlusion devices 75, 77 include a wire scaffold 78. In Figure 27E, the wires form a spherical shape, and the device is intended to substantially fill the aneurysm. In Figure 27F, the wires are stretched to form a partial spherical shape, and the device is not intended to substantially fill the aneurysm. The proximal and distal ends of the wire scaffold 78 may utilize a sealing member 76, in which case all of the wires are held together by the sealing member. The proximal end of the device may utilize a mesh or membrane, for example, to seal the neck of the aneurysm. The neck seal is delivered to the tip of a pusher, from which the neck seal is removed, and then a catheter is introduced into the neck seal to deliver additional embolic material, such as coils and / or liquid embolic material. Alternatively, the neck seal is delivered to the tip of an open-lumen pusher (similar to a microcatheter), the neck seal is placed into the target site, and then the open lumen of the pusher is used to deliver additional embolic material. The pusher is then removed. Alternatively, a mesh / membrane can be placed within the scaffold, as shown by element 74 in FIG. 27E. Placing the mesh or membrane in this manner essentially creates an occlusion region extending from the neck of the aneurysm to the top of the membrane. Subsequently introduced embolic material (i.e., coils or liquid embolic material) will be trapped within the region defined by the membrane. Different variations of this concept include a wire-formed scaffold, but the mesh / membrane may be positioned around the entire periphery of the scaffold, only the center of the scaffold, or only the distal tip of the scaffold. The cervical bridge assumes a collapsed configuration when stored within the delivery catheter and then assumes its expanded shape upon delivery and removal from the catheter (see Figures 27E-27F). The mesh / membrane material used may be composed of a polymer or metallic material.The mesh / membrane can be secured to the wire scaffold by adhesives, stitching, heat treatment, or other means. While a wire scaffold has been described, many variations are possible. For example, the scaffold may primarily utilize wire to form the scaffold, but link elements (think jewel pendants or chain links) may be selectively incorporated along the length of the wire to enhance flexibility. Alternatively, the scaffold may be constructed from laser-cut sheets.

[0125] FIG. 30 illustrates a mandrel and winding technique that can be used to wind a braided structure to form an occlusion device. This design utilizes tension and gravity to wind the braided structure. First, multiple wires 96 comprising the braided structure are placed on a mandrel 94. The top of the mandrel has multiple notches or grooves to accommodate the multiple wires. Alternatively, the wires may be placed on top of the mandrel and secured with tape or other means to initially maintain tension on the wires. Multiple weights 98 are placed at the bottom of the wires, and a braiding ring 100 is also utilized. The braiding ring has multiple notches to accommodate the multiple wires and is selectively movable up and down relative to the mandrel, but can also be locked in place. The braiding ring can be used to control the angle of the wire braided structure; holding the braiding ring in a high position allows for a tighter braid angle and a denser braid, while holding the braiding ring in a low position allows for a larger braid angle and a looser braid. The user can maintain a constant tension and a constant weave angle in the braided structure by lowering the braiding ring as they wind the wire over the mandrel. The user manually winds various wires over and under each other to form the wound structure. To maintain a constant weave angle, the braiding ring is lowered as the user winds each incremental section of the braided structure. The device can be heat set after the windings are performed to reinforce the shape.

[0126] Although the use of braiders to form braided devices has been described in several places in this description, these braiders typically utilize a longitudinally moving mandrel and a series of bobbins mounted within a carrier frame. In this case, the bobbins rotate in various configurations within the carrier frame. The rotation of the carrier and bobbins, coupled with the longitudinal movement of the mandrel, allows braiding of the device to occur. In a different embodiment, a rotatable braider may be used. That is, instead of bobbins housed within a rotating carrier or a rotating braider, the braider itself may have the freedom to rotate. Figure 32A shows a typical shape of intersection for a wire braided structure. Each line represents a wire, and therefore, four wire intersections form the indicated shape. For ease of reference, these four wire intersections will hereafter be referred to as cells. Because the braid angle in Figure 32A is constant, a diamond-type cell shape is typically produced during a typical braiding process. In addition to the rotation of the bobbins and carrier, further development is possible by adding rotation to the braider itself. Rotating the braider shifts the winding angle as it wraps around the mandrel, shifting the angle from a diamond-type shape to a more parallelogram-type configuration, allowing for more distorted shapes such as one of those shown in Figures 32B-32C. Rotating the frame clockwise produces one shape, while rotating the frame counterclockwise produces a different shape. This can be useful for creating different flexibility in select regions of the resulting braided device (i.e., occlusion device). Having the more elongated braided structure section of Figures 32B-32C allows for different stiffness characteristics in that region than the shape of Figure 32A. For example, a manufacturer may want to create a braided device with a general stiffness in the majority of the device but different stiffness characteristics in the center.As the central section of the braided structure is wound, the user can rotate the carrier frame to form cell shapes of the type shown in Figures 31B-31C. This allows for varying the stiffness characteristics of the device in specific regions. Such processes can be automated; for example, when the braiding process is typically automated, the amount of rotation of the carrier frame is also automated and can be considered a different variable in the winding operation. Other variables include the longitudinal speed of the mandrel, the rotation speed of the carrier and multiple bobbins that wrap the wire around the mandrel, the angle of the braided structure, etc.

[0127] Other embodiments may utilize a distal filling structure and a proximal neck bridge structure. The filling structure may take the form of a wire, hypotube, or sheet cut structure. The filling structure may be shaped into numerous configurations, such as straight, wavy, sinusoidal, and / or coiled, to facilitate occlusion of the target area. In one example, the filling structure may be fabricated from a nitinol wire having a diameter of approximately 0.002"-0.005". Other embodiments may utilize shape-setting polymers, cobalt-chromium, and spring-tempered stainless steel. In one example, each wire includes a tantalum coil for imaging, wrapped around the wire and extending over the entire wire or a sufficient length of the wire to allow visualization of the device during the procedure. The neck bridge may include a mesh braided element positioned at or just inside the neck of the aneurysm to prevent the filling structure from dislodging from the aneurysm. Alternatively, the neck bridge may comprise a structure including multiple disc-like elements, with one disc located inside the aneurysm and the other multiple discs located outside the aneurysm. The neck bridge may be a metallic (i.e., nitinol, stainless steel, cobalt-chromium) or polymer braided structure.

[0128] 35 shows a distal wire-filling structure 110 and a proximal mesh / neck bridge structure 112A used to occlude an aneurysm. The device is delivered from a catheter 8. In one embodiment, the distal filling structure 110 and the proximal mesh / neck bridge structure 112A are connected, and the entire system is compressed via a core wire-based compression system. In this case, a detachment system is incorporated into the core wire and the proximal end of the mesh / neck bridge to allow for device detachment. Any mechanical, thermal, or electrolytic detachment system can be used, including the other detachment concepts disclosed herein.

[0129] Figure 36 shows an embodiment similar to that of Figure 34, except that it includes a dual-disc neck bridge structure 112B. In this example, the neck bridge 112B may include multiple disc-like elements, with one disc located inside the aneurysm and multiple discs located outside the aneurysm.

[0130] In one embodiment, the filling structure 110 is secured to the distal portion of the neck bridge 112A / 112B. During delivery, the entire system is folded inside the catheter 8, with the filling structure 110 located at the distal end of the neck bridge. In a different embodiment, the neck bridge structure 112A / 112B may be pre-positioned at the distal end of the catheter 8 and located external to the catheter 8. In one embodiment, the catheter 8 extends through the neck bridge 112A / 112B to provide a lumen for delivery of additional embolic material into the aneurysm 14 via the neck bridge 112A / 112B.

[0131] In a different embodiment, the neck bridge structure 112B shown in Figure 34 may utilize one or more lumens, and the filling structure is delivered through the neck bridge 112B and into the aneurysm 14 via the one or more lumens. The filling structure is delivered via the catheter and neck bridge and will be deployed through the neck bridge after it has been deployed.

[0132] In one embodiment, the filling structure 110 is secured to the cervical bridge 112A / 112B proximal to the filling structure 110. The filling structure 110 and attached cervical bridge are pushed through the catheter 8 by a proximal pushing system. A detachment system (such as an electrolytic, thermal, mechanical, or other detachment system described herein or previously incorporated by reference) links the pusher to the cervical bridge. The pusher is used to push the cervical bridge and filling structure out of the catheter, and then the detachment system is used to detach the system from the pusher, which is then withdrawn. FIG. 37 shows a cross-sectional view of such an arrangement, with the filling structure 110 secured to the proximal portion of the cervical bridge (not shown), and the entire device is delivered through the catheter 8. Three filling structures are used. The filling structure 110 includes a wire 111 surrounded by a radiopaque coil 116 to aid visualization. The radiopaque coil 116, in one embodiment, comprises tantalum or tungsten and has a 0.001" thread shape, which is slightly larger in diameter than the wire 111 because the coil 116 is positioned to surround the wire 111. The cervical bridges 112A / 112B are positioned proximally of the filling structure. A proximal pusher, such as a core wire pusher, is connected to the cervical bridges 112A / 112B. A detachment system utilizing thermal, mechanical, or electrolytic means can separate the pusher from the cervical bridges 112A / 112B. Any of the detachment systems discussed herein and any of the systems incorporated by reference may also be used.

[0133] 38 and 39 show another embodiment in which the proximal neck bridge structure 112B (alternatively, 112A) includes an internal channel 124 connected to the catheter 8 so that a continuous lumen exists through the neck bridge 112B. The neck bridge 112B is located at the distal end of the catheter 8. In another embodiment, when the catheter 8 is positioned in place (i.e., near the aneurysm or treatment site), a portion of the neck bridge 112B is located proximal to the catheter 8 and a portion is located internal to the catheter 8, and a removable pushing element is used to push the neck bridge 112B out of the catheter 8. Alternatively, the catheter 8 can be retracted to expose the entire neck bridge 112B. Because the neck bridge 112B includes a lumen, the lumen can be used as a conduit for pushing embolic material (e.g., embolic coils) through the neck bridge 112B and into the treatment site (e.g., an aneurysm) when the neck bridge is properly positioned. The cervical bridge 112B prevents the embolic coil from detaching from the treatment site and may otherwise be pushed out of the catheter 8 to allow the catheter 8 to be withdrawn, or the catheter 8 may include a detachment system (thermal, mechanical, electrolytic, or other detachment devices described herein, or other detachment systems incorporated by reference herein) to detach the catheter from the cervical bridge.

[0134] U.S. Patent Application Publication No. 20150173772 discloses an embolic coil system that utilizes multiple detachment elements along the length of the coil to form a variable detachment system, whereby selective lengths of the coil are deployed within the target treatment site. The entire disclosure of this U.S. Patent Application Publication is incorporated herein by reference. One embodiment, shown in Figures 38-39, utilizes a variable detachment coil system based on the cervical bridge concept. The variable detachment system utilizes contact elements on the catheter that interconnect multiple links between multiple embolic coil segments, with the multiple links comprising degradable elements that degrade when the catheter contact elements electrically interconnect with the multiple coil rings to separate the coil segments. Element 124 in Figure 39 represents the inner lumen connecting the interior of the cervical bridge 112. This lumen is connected to a capsule 126 that contains a degradable linkage that separates the cervical bridge from the catheter delivery system. Multiple embolic coils 120, which are pushed through a catheter (see FIG. 38), include multiple links 122 that electrically interconnect with capsule elements 128 (see FIG. 40) to release the appropriate segments of the embolic coil within the vessel. The catheter 8 provides a delivery platform for both the multiple embolic coils and the cervical bridge (connected to the distal end of the catheter) delivered through the catheter. The inner lumen and attached cervical bridge are separated from the catheter by a degradable capsule 126. The capsule, as described above, can be detached using a detachment mechanism to detach the cervical bridge 112 and the inner lumen 124 connecting the interior of the cervical bridge from the catheter. Several wires 130 are used to provide electrical current to the capsules 126 and 128, and a voltage source (i.e., a battery) is located at the proximal end of the system, providing electrical current between the battery and the capsules. The inner lumen 24 may comprise a number of materials, including polymers, metals, and metal mesh.

[0135] Several embodiments have been described that utilize a neck bridge located at or within the neck of the aneurysm (FIG. 35) or a neck bridge having a portion located within the aneurysm and another portion located outside the aneurysm (FIG. 36). Another embodiment utilizes a floating neck bridge, in which the neck bridge is placed within the aneurysm and multiple filling structures or multiple embolic coils are placed within the aneurysm so that these embolic materials fill the interior space of the aneurysm and ultimately depress the neck bridge, causing it to seal the neck of the aneurysm. In one example, the catheter 8 placed in FIGS. 35-40 is a microcatheter having a diameter of 0.017"-0.021".

[0136] Another embodiment of an occlusion device 143 is shown in a compressed, elongated state during delivery within a catheter in Figure 41. It is shown in an expanded configuration upon emergence from catheter 8 in Figure 42. Device 143 includes multiple structural loops or struts 138 connected to a distal occlusion portion 140. When used within an aneurysm, proximal occlusion portion 140 forms a dome-shaped or concave occlusion region within the aneurysm, while multiple struts 138 assist occlusion portion 140 in expanding to fill the area beneath occlusion portion 140.

[0137] A plurality of connecting structures 142 are secured to the proximal contact portion 140 (e.g., by adhesive or welding) and to the plurality of struts 138 (e.g., by loops through which the struts 138 pass), thereby connecting the plurality of struts 138 to the proximal occlusion portion 140. The struts can be constructed of metal or polymer, such as nitinol wire or hypotubing, and radiopaque items can also be used to aid in imaging. The proximal occlusion portion 140 can have a preset curved shape or can comprise a thin, malleable material that can conform to the shape of the aneurysm. In one embodiment, the proximal occlusion portion 140 is a thin-film polymer (e.g., PTFE, ePTFE, polyethylene) or metal (e.g., nitinol, stainless steel) material. The plurality of struts 138 help control the expansion of the proximal contact portion and further help ensure gradual deployment of the device 143.

[0138] The proximal ends of the struts 138 are connected to the cylindrical collection band 136, for example, by passing through openings in the collection band 136. A coil 134 (stainless steel in one embodiment) is connected to the proximal end of the collection band 136 and to the distal end of the proximal band 132 on the pusher 131, which assists in pushing the struts forward and opening, as well as the proximal occlusion portion 140. The coil 134 assumes a compressed shape when the device 143 is within the catheter 8, causing the struts 138 to also compress and assume an elongated shape. Thus, the coil 134 has stored energy, and as the device 143 is delivered and the struts 138 begin to open, the coil 134 releases this stored energy, assisting in further expansion of the struts, as well as the attached proximal contact portion 140.

[0139] The pusher 131 may include a core wire or hypotube system, allowing the user to manipulate the device 143 through the catheter 8 and blood vessel. A detachment system may be provided at a distal location of the pusher. In one embodiment, the coil 134 is part of the detachment system, with a detachable tether disposed within the lumen of the coil 134. Wires may connect one end of the coil, which connect to a voltage source, such as a battery, at the proximal end of the system, allowing the user to initiate a detachment sequence (e.g., by pressing a button) that heats the coil and detaches the tether to detach the device from the pusher. The detachment system may be flush with the coil 134 or proximal to the coil 134 to prevent the coil 134 from advancing into the blood vessel. In one embodiment, the detachment system utilizes a tether that connects the collection band 136 through the coil 134, rigidly connecting the coil to the element 132. Thus, when the detachment sequence is initiated and the device is deployed, the proximal end of the pusher is attached to proximal band 132, so the tether separates but the coil remains attached to the pusher.

[0140] Additionally, tensioning element 141 can be used to connect proximal occlusion portion 140 to struts 138. Tensioning element 141 can be a thin wire or tether and helps control the expansion of proximal portion 140 and struts 138 when delivered, allowing for slower or less abrupt opening.

[0141] In one embodiment, the struts 138 are heat treated to create a shape-memory open configuration, as shown in FIG. 40 . This shape memory allows the struts 138 to quickly open and assume their memorized open configuration, helping the tether control the release of the device during delivery. Alternatively, tension element 141 may be attached to the region between the proximal occlusion portion 140 and the pusher 131, or to the proximal side of the struts 138, band 136, coil 134, element 132, or base of the pusher 131. Securing the proximal end of the tether to a non-strut element has the advantage of securing the tether to an element that does not expand, resulting in very precise control over deployment. Securing the proximal end of the tether to a strut 138 does not limit expansion, since the proximal end is secured to something that expands during deployment. The location of the proximal end of the tether is adjusted based on whether the user desires more precise or less precise control of the device's expansion during deployment, with the materials used in the device and the size of the device being important variables during operation.

[0142] Figures 43-45 show an occlusion device 145 having a concave top occlusion element 144A and a concave bottom occlusion element 144B that expand against the dome and neck of the aneurysm, respectively. The top and bottom elements 144A, 144B can be constructed from a variety of materials, including metal mesh, metal sheet, and polymer. A coil 146 connects the top and bottom occlusion elements 144A, 144B, connecting both elements 144A, 144B and allowing for variable distances to accommodate different aneurysm sizes. The top element 114A is positioned first within the aneurysm, and the bottom element 114B is the last element to exit the catheter. As shown in Figures 44 and 45, the device 145 may optionally include a frame 148 that expands within the top and bottom elements 144A, 144B. Frame 148 has multiple loops that extend radially across the open portions of the concave openings of elements 144A, 144B, thereby serving as a scaffold for the opening and closing of the top and bottom elements, while also providing more precisely controlled expansion and contraction of the device. Figure 45 shows device 145 in its collapsed configuration, as it is during delivery through a catheter. When collapsed, frame element 148 lies over a portion of the coil (think of it as an umbrella-like frame in its collapsed state compared to its expanded state). When expanded, the frame elements lie flat and flush within the top and bottom elements, respectively.

[0143] Other embodiments may utilize the tip filling structure 110 described above and shown in Figures 35-36, but may also utilize the device shown in Figure 1, which includes a retaining portion 10 and a support portion 12.

[0144] Various mandrels and winding techniques used to form occlusion devices have been described. A different embodiment utilizes a removable mandrel, in which case fracturing, chemical dissolution, or other techniques can be used to remove the mandrel after the fabricated device has been braided over the mandrel. The fabricated device may be any number of devices, including occlusion devices, such as braided therapeutic devices. Conventional braiding techniques utilize braiding a device over a mandrel, heat-setting the device over the mandrel, and then removing the mandrel. The mandrel can optionally include multiple pins around which the device is braided. In this case, a non-cylindrical, tapered occlusion device is formed (i.e., smaller at both ends than in the middle), and removing the mandrel can be difficult due to the tapered shape of the mandrel and the occlusion device. One way to solve this problem is to use a mandrel that is removable by mechanical means (i.e., fracturing) or chemical means (i.e., chemical dissolution), and then removing the mandrel, leaving the braided device.

[0145] In one embodiment, the mandrel is constructed of ceramic or glass. Both ceramic and glass are highly brittle, so the mandrel can be mechanically broken with a hammer to remove it after the device is formed. If a glass mandrel is used, the glass can be coated with a silicone or latex material to prevent the wound device from slipping over the mandrel. In another embodiment, an aluminum mandrel is used, and a concentrated sodium hydroxide solution is used to dissolve the mandrel. Concentrated (i.e., 1-10 M) sodium hydroxide solution can be used at a high enough temperature (i.e., 100-150 degrees Fahrenheit) to ensure it remains liquid. While aluminum mandrels dissolve slowly, this technique will not dissolve other materials, such as Nitinol, that may be used to wind interventional devices. Thus, the mandrel disappears, leaving the device. In another embodiment, the mandrel is a sand mold. The sand mandrel can be removed with a liquid jet, and when the formed mandrel is destroyed, simply sand remains. In one example, the mandrel has an aluminum core, and the sand mold is constructed to cover the aluminum core. Another embodiment may utilize a removable mandrel that includes a wire-forming structure similar to the braided structure formed over the mandrel. Thus, the mandrel includes a first braided structure, and a second braided interventional device is wound over the braided mandrel. The braided mandrel can be easily compressed to remove the braided interventional device. The braided mandrel should include any wire structure that is strong and compressible and can withstand the high curing temperatures of heat curing, such as 316 stainless steel or 321 stainless steel. A different embodiment uses a mandrel including a first layer (i.e., a typical metal mandrel) and a second layer, where the second layer includes any of the removable mandrel elements described herein to form a double or multi-layer braided interventional device.The user winds the first layer of the device over the base mandrel. A removable second mandrel layer is then placed over the first mandrel layer and first braided layer of the interventional device. The second layer of the interventional device is then wound over the second (removable) mandrel layer. The removable mandrel section is then removed, leaving the first mandrel and multi-layer interventional device. While this process has been described to form a two- or double-layer device, additional removable mandrels may be added to form three-, four-, five-, etc.-layer braided interventional devices.

[0146] While the present invention has been described in terms of particular embodiments and applications, those skilled in the art can, with reference to the present teachings, derive additional embodiments and modifications without exceeding the scope of the invention as set forth in the claims or departing from the principles of the invention. Accordingly, it will be understood that the drawings and this specification have been provided as examples to facilitate a comprehensive understanding of the invention, and that the drawings and this specification do not constitute limitations on the scope of the invention.

Claims

1. A catheter, a cervical bridge, the cervical bridge including at least one disk-shaped element including a mesh; and a cylindrically shaped inner braided portion having an inner channel that passes through the inner lumen of the cervical bridge and continues through the cervical bridge, the inner channel being connected to the catheter to form a continuous lumen that is used as a conduit for delivering embolic material through the cervical bridge into a treatment site; An occlusion system including:

2. The occlusion system of claim 1 , further comprising an embolic coil pushable through the internal channel to the treatment site.

3. The occlusion system of claim 1 , further comprising a detachment system for selectively detaching the cervical bridge from the catheter.

4. The occlusion system of claim 1 , wherein the cervical bridge comprises two disk-shaped elements.

5. The occlusion system of claim 2 , wherein the embolic coil is secured to a distal portion of the cervical bridge.

6. The occlusion system of claim 1 , wherein the neck bridge is disposed at the distal end and exterior of the catheter.

7. 10. The occlusion system of claim 1, further comprising a pusher and a detachment system for detaching the cervical bridge from the pusher.

8. 10. The occlusion system of claim 1, further comprising a pusher and a coil detachment system for placing a selected length of the embolic coil within the treatment site, the coil detachment system being disposed within the catheter and including a plurality of embolic coil segments of the embolic coil and a plurality of links between the plurality of embolic coil segments, the links comprising disassemblable elements for separating the embolic coil segments.

9. 2. The occlusion system of claim 1, wherein the cervical bridge comprises a first disc-shaped element, a second disc-shaped element, and a portion between the first disc-shaped element and the second disc-shaped element, the portion having a diameter smaller than the diameters of the first disc-shaped element and the second disc-shaped element.

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