Embolic coil delivery systems and components

Abstract

Systems for delivering embolic coil devices and components for such systems are described. The system includes a flexible elongate delivery shaft having a distal region and an embolic coil device detachably connected to the distal region of the elongate delivery shaft. In some forms, when detachably connected, at least some of the coil windings of the embolic coil device, such as those in a proximal section of the coil windings, are in an elastically longitudinally compressed state. When the embolic coil device is separated from the delivery shaft, the coil windings are elastically moved to a longitudinally extended state, where the coil windings in the longitudinally extended state are more splayed than they in the elastically longitudinally compressed state. In some forms, the system has a coil separation interface at a distal region of the flexible elongate delivery shaft. The coil separation interface includes a distal tubular section and a bridge section proximal to the distal tubular section. The bridge segment includes a bridge wall or other bridge member defining an upper surface, a lower surface, a proximally facing edge spanning between the upper surface and the lower surface, and a distally facing edge spanning between the upper surface and the lower surface. The bridge segment further defines a lumen between a lower surface of the bridge wall or other bridge component and a bottom wall of the bridge segment. Embolic coil devices and bridging members configured for use in such systems are also described.

Description

[0001] Citation of Related Applications

[0002] This application claims the benefit of priority to U.S. Provisional Patent Application Serial No. 63 / 354,078, filed on June 21, 2022, and U.S. Provisional Patent Application Serial No. 63 / 354,093, filed on June 21, 2022, each of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present disclosure generally relates to implantation systems for embolic coil devices for creating embolism or vascular occlusion in a patient's blood vessel, as well as devices and components used in such systems. Background Art

[0004] Embolic coil devices are used to treat a variety of medical conditions, including, for example, the treatment of intravascular aneurysms. Embolic coils are typically in the form of soft, helically wound coils formed by winding a wire (e.g., platinum or platinum alloy wire) around a main shaft rod. In some known forms, the coil so formed is then wrapped around a larger secondary shaft rod and heat treated to impart a memory of the secondary shape. The secondary shape can also be imparted by cold forming. When the coil is delivered from a tubular device (e.g., a catheter) to the treatment site, the coil will transition to or tend toward its more convoluted secondary shape.

[0005] Various arrangements are known for detaching the coil from the delivery shaft, including, inter alia, electrolytic and mechanical detachment arrangements. Many known mechanical detachment arrangements have a delivery shaft defining a lumen and a pull wire (also referred to as a "release" wire) that interfaces with the coil device and can be moved proximally within the shaft lumen to cause detachment of the embolic coil device.

[0006] There remains a need for an embolic coil delivery system incorporating a breakaway feature or mechanical breakaway arrangement that is convenient to manufacture and easy and reliable to use. Aspects of the present disclosure address these needs. Summary of the invention

[0007] In some aspects, a system for delivering an embolic coil device is provided. The system includes a flexible, elongated delivery shaft having a distal region. The embolic coil device is detachably connected to the distal region of the elongated delivery shaft, wherein the coil windings of the embolic coil device are in an elastic longitudinally compressed state. When the embolic coil device is separated from the elongated delivery shaft, the coil windings are elastically moved to a longitudinally extended state, wherein the coil windings are more open in the longitudinally extended state than they are in an elastic longitudinally compressed state. The coil windings involved may represent some or all of the coil windings of the embolic coil device. In some forms, the coil windings involved are only some of the coil windings of the total coil windings, and a first segment of the coil windings operable as described above is provided, the first segment preferably being located in the proximal region of the coil device. The side of the first segment may have a proximal segment, the proximal segment having a relatively closed (narrower spacing) coil winding compared to the coil windings of the first segment. Additionally or alternatively, the first segment may be flanked by a distal segment having a relatively closed coil winding compared to the coil winding of the first segment.

[0008] In some additional aspects, a system for delivering an embolic coil device is provided. The system includes a flexible, elongated delivery shaft that defines a lumen and has a distal region and a coil separation interface at the distal region of the elongated delivery shaft. The coil separation interface includes a distal tubular segment and a bridging segment proximal to the distal tubular segment. The bridging segment includes a bridging component, the bridging component is, for example, a bridging wall having an upper surface and a lower surface, and the bridging segment defines a lumen between the lower surface of the bridging wall or other bridging components and the bottom wall of the bridging segment. The embolic coil device is detachably connected to the distal region of the elongated delivery shaft, and optionally, the proximal end of the coil winding of the embolic coil device is located at a position distal to the distal tubular segment of the elongated delivery shaft. The pull wire extends through the lumen of the elongated delivery shaft and interacts with the retaining member of the embolic coil device. The proximal retraction of the pull wire causes the embolic coil device to separate from the elongated delivery shaft. In some forms, the distal tubular segment and the bridging segment are provided by a bridging member, which may also have a proximal tubular segment proximal to the bridging segment and / or may define at least one sidewall opening positioned to provide an opening portion proximal to a proximal surface of a bridging wall or other bridging component providing the bridging segment. The bridging member may be a unitary structure formed from a single section of tubing and may be attached to the distal end of a section of metal hypotube that provides all or a portion of the remainder of the elongated delivery shaft. In some forms, the bridging wall defines a proximally facing edge spanning between the upper and lower surfaces of the bridging wall and a distally facing edge spanning between the upper and lower surfaces of the bridging wall.

[0009] In other aspects, a bridging member in a separation interface for an embolic coil device delivery system is provided. The bridging member includes a distal tubular segment, a proximal tubular segment, and an intermediate segment between the distal tubular segment and the proximal tubular segment. The intermediate segment includes a bridging component, which is, for example, a bridging wall defining an upper surface and a lower surface. The intermediate segment also defines a lumen between the lower surface of the bridging wall or other bridging component and the bottom wall of the intermediate segment. The bridging member can be an integral structure and can be formed by a single-segment tube, and can have various configurations for the bridging wall, including a substantially planar or multiple curved bridging walls. In some forms, the bridging wall has a proximally facing edge spanning between the upper and lower surfaces of the bridging wall, and a distally facing edge spanning between the upper and lower surfaces of the bridging wall.

[0010] In other aspects, embolic coil devices configured for use in the systems described above and elsewhere herein are provided.

[0011] In other aspects, methods for making and using the systems and embolic coil devices as described above and elsewhere herein are provided.

[0012] Further embodiments, as well as features and advantages of the embodiments described herein, will be apparent to persons skilled in the relevant art(s) from the description herein. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 An illustration of one embodiment of an embolic coil delivery system herein received within a catheter with portions of the catheter cut away to show system components therein is provided.

[0014] Figure 2 Provided Figure 1 Magnified view of part 2S.

[0015] Figure 3 Provided Figure 1 A cross-sectional view of the components of the system in the area of ​​the delivery shaft / coil device interface.

[0016] Figure 4 Provides the formation Figure 1 Side view of a bridging member of the distal-most segment of the delivery shaft of the system.

[0017] Figure 5 Provided Figure 4 Right end view of the bridging member.

[0018] Figure 6 Provided along Figure 4 A cross-sectional view taken along line XS6-XS6 and observed along the direction of the arrow.

[0019] Figure 7 Provided Figure 4 A three-dimensional view of a bridging member.

[0020] Figure 8 Provided is a method of detachably coupling the delivery shaft and the embolic coil device prior to detachably coupling the delivery shaft and the embolic coil device. Figure 1 Illustration of the system's embolic coil device and the distal end of the delivery shaft.

[0021] Fig. 9 Provided Figure 8 An enlarged view of part 9S.

[0022] Fig.10 Provided Figure 8 Magnified view of section 10S.

[0023] Fig.11 After the delivery shaft and the embolic coil device are detachably connected, Figure 1 Illustration of the system's embolic coil device and the distal end of the delivery shaft.

[0024] Fig.12 Provided Fig.11 Magnified view of section 12S.

[0025] Fig.13 A side view of an alternative bridging member for forming a distal-most segment of a delivery shaft of the embolic coil delivery system herein is provided.

[0026] Fig.14 Provided Fig.13 Right end view of the bridging member.

[0027] Fig.15 Provided Fig.13 A top view of a bridging member.

[0028] Fig.16 Provided along Fig.15 A cross-sectional view taken along line XS16-XS16 and observed along the direction of the arrow.

[0029] Fig.17 Provided Fig.13 A three-dimensional view of a bridging member.

[0030] Fig.18 A side view of another alternative bridging member for forming a distal-most segment of a delivery shaft of the embolic coil delivery system herein is provided.

[0031] Fig.19 Provided Fig.18 A three-dimensional view of a bridging member.

[0032] Fig. 20 Provides a combination of Fig.18 Illustration of one embodiment of an embolic coil delivery system with a bridging member.

[0033] Fig.21 Provided Fig. 20 An enlarged view of portion S21 in FIG. DETAILED DESCRIPTION

[0034] Reference will now be made to specific embodiments, some of which are illustrated in the accompanying drawings, and specific language will be used to describe them. However, it should be understood that this is not intended to limit the scope of the present disclosure. Those skilled in the art of the present disclosure will generally appreciate any changes and further modifications in the described specific embodiments, as well as any further applications of the principles described herein.

[0035] As described above, various aspects of the present disclosure relate to systems and related devices, components, and methods for delivering an embolic device to a patient. The system may include an elongated delivery shaft and an embolic device (e.g., an embolic coil device) detachably connected to a distal region of the delivery shaft, wherein the medical device can be detached from the delivery shaft by proximal movement of a pull wire.

[0036] As used herein, the term "proximal" means close to an operator and the term "distal" means away from an operator.

[0037] Spatially relative terms, such as "lower," "upper," "below," "above," "above," etc., may be used to describe the relationship of an element and / or feature to another element or feature, such as depicted in the figures. It should be understood that the spatially relative terms are intended to encompass different operations of the system, device, or assembly in use in addition to the orientation described or depicted in the figures. For example, if the device or component depicted in the figures were inverted, an element shown and described as "upper" would be oriented "lower."

[0038] Turning now to the accompanying drawings, Figure 1A system 10 is shown for delivering an embolic device 12 to a vascular space (e.g., an aneurysm) contained within the lumen of a catheter 300. The embolic device 12 can be formed as an embolic coil device 14 having a plurality of coil windings 16 extending from a proximal end 16A to a distal end 16B. Typically, the coil windings 16 are made of wire, typically made of a metal such as platinum, a platinum alloy, or a superelastic metal alloy (e.g., a superelastic nickel / titanium alloy such as nitinol). The diameter of the wire forming the coil windings 16 can be in the range of about 0.005 mm to about 0.15 mm. The coil formed by the windings 16 can have an outer major diameter between about 0.075 and about 1 mm, and in some forms, particularly those coil devices 14 intended for neurovascular applications, will have an outer major diameter between about 0.2 mm and about 0.5 mm.

[0039] The axial length of the embolic coil device 14 typically falls within the range of about 0.5 to about 100 cm, more typically about 2 to 40 cm. However, it will be appreciated that other axial lengths may be employed depending on the application. Likewise, it will be appreciated that the embolic coil device 14 may have a thrombogenic material, such as fibers (not shown), connected to the coil windings 16 to enhance its prothrombotic properties, and that other embolic coil devices described herein may similarly include such thrombogenic materials.

[0040] Continue to refer Figure 1 as well as Figure 2 , Figure 8 , Fig. 9 and Fig.10 , the coil device 14 includes a proximal retaining member in the form of a ring 18. The retaining member in the illustrated embodiment is formed as a ring 18 by a section of filament 20 attached to the coil device 14. For example, the filament 20 can be formed by a suitable polymer or metal material, and in some variations can have a diameter of about 0.01 to about 0.1 mm. Suture material, especially durable (non-bioabsorbable) suture material, can be suitable for use as filament 20. Ring 18 provides two filament segments 20A and 20B extending into and attached to the coil winding 16, as discussed further below. Although the retaining member specifically shown is a ring 18, other known retaining members can be used, and other retaining members include balls, hooks, buckles or other similar elements as examples, which can promote the detachable connection of the embolic coil device with the delivery shaft.

[0041] The delivery system 10 also includes a flexible, elongated delivery shaft 22 having a distal end 24, a proximal end 26, and a lumen 28 therebetween. The delivery shaft 22 can be formed of any suitable material, including, as an example, a polymer material, a metal material, or a combination thereof. Metallic hypotube materials, such as stainless steel hypotubes or nitinol hypotube materials, can be used. As exemplary polymer materials, flexible and lubricating materials, such as polyimide, polytetrafluoroethylene (PTFE), polyetheretherketone (PEEK), fluorinated ethylene propylene (FEP), etc., can be used. Similarly, a combination of different metallic hypotube materials can generally be used, such as a combination of a first stainless steel hypotube segment attached (e.g., welded) to a second different stainless steel hypotube segment. For example, the second stainless steel hypotube segment can be located distally of the first hypotube segment and can be more flexible and / or shorter than the first hypotube segment. This can provide an integral delivery shaft 22 that is more flexible in its distal region than in its proximal region. In some versions, other material combinations that provide a more flexible distal region and a less flexible proximal region may also be used.

[0042] In some aspects, the metal hypotube material, and therefore the segments of the delivery shaft 22 made therefrom, can have an inner diameter in the range of about 0.5 to about 0.9 mm and / or an outer diameter in the range of about 0.6 to about 1 mm. In some preferred small diameter forms, such hypotube materials will have an inner diameter in the range of about 0.1 to about 0.4 mm and / or an outer diameter in the range of about 0.2 to about 0.5 mm. The wall thickness of the hypotube material between the inner diameter and the outer diameter can be in the range of about 0.05 to about 0.25 mm.

[0043] The length of delivery shaft 22 between distal end 24 and proximal end 26 generally allows the shaft to be advanced intravascularly to a target site for delivery of coil device 14 while keeping proximal end 26 outside the patient's body. For example, delivery shaft 22 may have a length in the range of about 1 to about 2 meters.

[0044] Specific reference Figure 1 , Figure 2 and Figure 3 The system 10 also includes an elongated pull wire 30 disposed within the lumen 28 of the delivery shaft 22. The elongated pull wire 30 has a distal end 32 (see Figure 3 ) and proximal 34 (see Figure 1). The elongated pull wire 30 is typically formed of a flexible material that provides sufficient column strength to avoid breakage or kinking during use of the system 10. For example, the elongated pull wire 30 can be formed of one or more polymer or metal materials or a combination thereof. The pull wire 30 can be formed of a metal such as nitinol, titanium, a titanium alloy, platinum, stainless steel, etc. The diameter of the pull wire 30 is less than the diameter of the lumen 28 of the elongated delivery shaft 22. In an exemplary embodiment, the pull wire 30 is formed of nitinol, optionally coated with a lubricating polymer (e.g., polytetrafluoroethylene (PTFE)), and has an outer diameter of approximately 0.1 mm.

[0045] The system 10 may also include an arrangement for preventing accidental proximal retraction of the puller wire 30, which may result in accidental release of the coil device 14. Figure 1 As shown, at a first location 36, the delivery shaft 22 is attached to the pull wire 30. The attachment can be provided, for example, by a quantity of adhesive 38, but other attachment means can be used, such as welding or frictional engagement provided by one or more folds of the shaft 22 against the outer surface of the pull wire 30. The attachment fixes the relative position of the shaft 22 and the pull wire 30. At a second location 40 distal to the first location 36, the delivery shaft 22 has a portion where the shaft 22 is configured to selectively break and detach in response to a bending force applied at the first location 36 (compared to the portions of the shaft 22 flanking the location 36 on either side). Thereafter, the detached proximal piece of the shaft 22 (which is attached to the pull wire 30 at the location 36) can be moved proximally (e.g., pulled) to retract the pull wire 30 proximally within the lumen 28 in a sliding motion, thereby causing detachment of the embolic coil device 14, which will be discussed in more detail below. In this manner, system 10 may be used to advance embolic coil device 14 to a desired target location in a patient's vasculature, after which shaft 22 may be broken and separated at location 40 and the separated proximal piece of shaft 22 may be pulled proximally to cause separation of coil device 14 .

[0046] Now we will refer to Figures 1 to 121 to describe an embodiment in which the distal region of the shaft 22 is advantageously configured to provide an interface for detachable connection and release of the embolic coil device 14. In the illustrated embodiment, a bridging member 44 provides the distal-most segment of the shaft 22. The bridging member 44 extends from a distal end 46 providing the distal end 24 of the shaft 22 to a proximal end 48. The bridging member 44 typically has three segments, a distal segment 50, an intermediate or bridging segment 52, and a proximal segment 54. In the illustrated embodiment, the distal segment 50 is configured as a tubular segment defining a lumen 55 and a distally facing full circumferential end face 56. The full circumferential end face 56 advantageously provides a complete 360-degree surface, preferably an annular surface having an outer circular circumference and an inner circular circumference, for interfacing (e.g., abutting) with the proximal end 16A of the coil winding 16 of the coil device 14. It should be understood that other embodiments may have other end face configurations for the bridging member 44, including those in which the end face does not provide a full 360 degree circumferential end face facing distally; however, a substantially distal facing end face, such as an end face providing a coplanar end face of at least 270 degrees or at least 320 degrees around the circumference (this surface range being continuous in some forms and discontinuous in other forms) would be advantageous and desirable to provide. The end face 56 can have an outer circumference that is at least as large as the major outer diameter of the coil formed at the proximal end 16A of the coil winding 16, and may be larger than the major outer diameter. The intermediate section 52 of the bridging member 44 provides a transverse bridging component, preferably in the form of a bridging wall 58, which extends transversely (preferably perpendicularly) to the longitudinal axis of the delivery shaft 22. As shown, the longitudinal cross-section of the bridging wall 58 can be rectangular (see, e.g., Figure 3). In other embodiments, the bridging wall 58 or other transverse bridging member can have another longitudinal cross-sectional shape, such as another polygonal or circular longitudinal cross-sectional shape. The bridging wall 58 defines an upper surface 60, a lower surface 62, an edge 64 facing the distal side, and an edge 66 facing the proximal side. The edges 64 and 66 span between the upper surface 60 and the lower surface 62 of the bridging wall 58. The intermediate segment 52 also defines at least one side wall opening, such as a bridging side opening 68 and / or an opposite side opening 70, which can, for example, provide a channel to facilitate assembly steps during the manufacturing process of the system 10, particularly the coordination and assembly of the ring 18 of the coil device 14, which is fixed around the pull wire 30 at the proximal position of the bridging wall 58 or other transverse bridging member. To facilitate these purposes, at least one side opening (e.g., opening 68 and / or opening 70) can have a substantially maximum width in a direction perpendicular to the longitudinal axis of the bridge member 44, for example, such a width is at least 40%, or at least 50%, or at least 60% of the value of the corresponding width of the bridge member that extends longitudinally with the opening. Additionally or alternatively, the at least one side opening (e.g., opening 68 and / or 70) can have a substantially maximum length in the direction of the longitudinal axis of the bridge member 44, for example, such a length is at least equal to and in some forms greater than (e.g., at least 150% or at least 200%) the value of the maximum width of the opening in a direction perpendicular to the longitudinal axis of the bridge member 44. Likewise, the at least one side opening (e.g., opening 68 and / or opening 70) can be positioned so that a portion of the opening appears proximal to the proximal surface of the bridging wall 58 or other transverse bridging member, for example, where such portion of the opening is no more than 200%, or in some forms no more than 100%, of a value equal to the width of the bridging member 44 longitudinally coextensive with the opening. As in the depicted embodiment, the upper surface 60 of the bridging wall 58 can provide the outermost (upper) surface of the bridging member 44 in the longitudinal segment of the bridging member 44 (or generally the shaft 22) where the bridging wall 58 appears (the bridging member 44 does not have a tubular wall surrounding the bridging wall 58). The opposing wall portions 72 and 74 of the intermediate segment 52 span between the openings 68 and 70.

[0047] The shape of the proximal segment 54 of the bridging member 44 is generally tubular. In some embodiments, the proximal segment 54 can define a first sidewall opening 76 and a second sidewall opening 78 that are opposite to each other. The openings 76 and 78 in the illustrated embodiment can provide a means for installing the bridging member 44 during the manufacturing stage of the bridging member 44 or during its processing in the assembly step, although the openings 76 and 78 or other similar openings can also provide, for example, a line of sight or other passages leading to the interior of the bridging member 44. It should be understood that in other embodiments, there may be no opening 68 and / or opening 78. The proximal segment 54 provides the proximal end 48 of the bridging member 44 and defines a lumen 79 and a full circumferential end face 80 facing the proximal side. The full circumferential end face 80 advantageously provides a complete 360-degree surface for end-to-end attachment of the bridging member 44 to an adjacent segment of the delivery shaft 22, such as provided by an adjacent section of a metal (e.g., stainless steel) hypotube or other tube material. In some forms, the attachment can be a welded attachment.

[0048] The bridging member 44 defines a bridging wall lumen 82 between the lower surface 62 of the bridging wall 58 and the inner tubular surface 84 of the bridging member 44. The bridging wall lumen 82 generally has a smaller cross-sectional lumen area than the lumen 55 of the distal segment 50 of the bridging member 44 and the lumen 79 of the proximal segment 54 of the bridging member 44. As in the illustrated embodiment, the bridging wall lumen 82 can manage the position of the filament material 20 passing through the lumen. In other embodiments, the bridging wall lumen 82 can be used to manage the position of the pull wire 30 when the pull wire 30 is arranged to pass through the lumen 82, for example, where the filament 20 can pass above the upper surface 60 of the bridging wall and position the loop 18 around the pull wire 30 in an orientation generally opposite to the orientation depicted. The bridging wall 58 and lumen 82 can be appropriately shaped and / or sized for these and other arrangements. Generally speaking, the bridging wall 58 separates the bridging wall lumen 82 from an area appearing above the upper surface 60 of the bridging wall 58, such that different component portions of the system (e.g., portions of a pull wire or retaining member) can be held separate from one another by the bridging wall 58, with one component passing through the lumen 82 while another component passes above and potentially in contact with the upper surface 60 of the bridging wall 58.

[0049] In the illustrated embodiment, the bridging wall 58 of the bridging member 44 has a non-planar shape. Specifically, the bridging wall 58 is a central curved segment 58A having a radially inward curve (see, for example, Figure 7 ) of the multi-curved wall portion, the side of the central curved segment has a first curved segment 58B and a second curved segment 58C that are curved radially outward. Therefore, the central curved segment 58A defines a concave curved surface portion 60A of the upper surface 60 of the bridging wall 58 (see, for example, Figure 6), the first curved segment 58B and the second curved segment 58C define convex curved surface portions 60B and 60C on the upper surface 60. On the other hand, the central curved segment 58A defines a convex curved surface portion 62A of the lower surface 62 of the bridge wall 58, and the first curved segment 58B and the second curved segment 58C define concave curved surface portions 62B and 62C of the outer surface 60. In the illustrated embodiment, the central curved segment 58A defines a longitudinal channel 86 for slidably receiving the pull wire 30.

[0050] The bridging member 44 and other bridging members disclosed herein can be an integral structure. Such a bridging member can be formed by a single-segment tube, such as a single-segment metal (e.g., stainless steel) hypotube, which can have the same size and / or other features as described herein for the hypotube material of the delivery shaft 22. The hypotube or other tube material used to form the bridging member 44 and other bridging members herein can be cut and formed to provide the disclosed bridging member features. As an example, forming operations such as bending and stamping can be used. The bridging member formed by a single-segment tube is advantageous in manufacturing because it is not necessary to assemble and attach multiple parts together to manufacture the bridging member, and the size of the bridging member may be very small and therefore there are challenges in processing and attachment. The bridging member 44 and other bridging members described herein can also be manufactured using three-dimensional metal printing to reduce or eliminate the need for metal forming processes such as bending or stamping, while still providing an integral structural bridging member. It should be understood that the bridging member 44 or other bridging members described herein can also be manufactured by connecting (e.g., welding) multiple metals or other pieces together. In some aspects, bridge member 44 and other bridge members described herein can have a longitudinal length of no greater than about 10 mm, or no greater than about 5 mm, typically in the range of about 1 mm to about 5 mm, or about 1 to about 3 mm.

[0051] In the separation operation, the pull wire 30 in the lumen 28 of the delivery shaft 22 is pulled proximally (for example, after the shaft 22 is disconnected at position 40 in the presence of the above-mentioned release arrangement) until the distal end 32 of the pull wire 30 passes through and proximally exceeds the ring 18. This releases the ring 18 so that it moves distally through the bridging wall lumen 82 and leaves the distal end 46 of the bridging member 44. As a result, the coil device 14 is separated from the delivery shaft 22. In one mode of use, before separating the coil device 14, the shaft 22 can be used to push the coil device 14 out of the distal end 302 of the catheter 300 at the target blood vessel site for delivery, wherein the coil device contacts the blood vessel wall at the site and stays in place. This operation can position the bridging member 44 to be distally beyond the distal end 302 of the catheter 300. Then, with the bridging member deployed beyond the distal end 302 of the catheter 300, the proximal movement of the pull wire 30 and the resulting separation of the coil device 14 can occur.

[0052] Other bridging member structures and delivery systems incorporating the same are contemplated herein. Figures 13 to 17 , an alternative embodiment of a bridging member 144 is shown. Bridging member 144 can have features corresponding to features of bridging member 44, and these features of bridge member 144 are numbered correspondingly to those features of bridge member 44, but in a 100 series number (e.g., 144 vs. 44, 146 vs. 46, etc.), so the corresponding description will not be repeated here. Bridging member 144 differs from bridging member 44 in terms of a bridging wall 158 and a bridging wall lumen 182 partially defined by bridging wall 158. Specifically, bridging wall 158 is configured as a generally straight wall extending perpendicular to the longitudinal axis of bridging member 144. Bridging wall 158 is configured as a first bridging wall member 158A and a second bridging wall member 158B separated by a gap 158G. The bridging wall lumen 182 of the bridging member 144 has a generally straight upper wall provided by the lower surface 162 of the bridging wall 158, which is adjacent to a continuously curved wall providing a curved tube surface 184. The lower surface 162 and the tube surface 184 define the shape of the bridging wall lumen 182, which may be generally "D" shaped.

[0053] As mentioned above, in Figures 1 to 12 In the disclosed embodiment, the bridge member 144 may replace the bridge member 44. In doing so, the pull wire 30 will be located above and generally against the upper surface 160 of the bridge wall 158, the filament segments 20A and 20B of the filament material 20 attached to the embolic coil device 14 will extend through the distal end of the bridge member 144 and through the bridge wall lumen 182, and provide a loop 18 located proximal to the bridge wall 158 through which the pull wire 30 extends.

[0054] Figures 18 to 21, which may further be used in an alternative embolic coil delivery system 210 having an alternative delivery shaft / embolic coil device retention interface, as discussed further below. A bridging member 244 may have features corresponding to those of the bridging member 144, which are numbered correspondingly to those of the bridging member 144, but in the 200 series (e.g., 244 versus 144, 246 versus 146, etc.), and thus the corresponding descriptions will not be repeated herein. The bridging member 244 differs from the bridging member 144 in that the bridging member 244 has a longer tubular distal segment 250, which further has a ball receiving opening 206 for receiving a retention ball as described below. The opening 206 may be at a position around the circumference of the bridging member 244 that is aligned with a wall surface 284 that partially defines a bridging wall lumen 282. In this manner, as the pull wire 230 extends over the upper surface 260 of the bridging wall 258 and distally through the tubular distal section 250 , the bridging wall 258 will facilitate pulling the pull wire 230 to a position within the tubular distal section 250 opposite the ball receiving opening 206 .

[0055] In general, the embolic coil delivery system 210 can have features corresponding to those of the version of system 10 discussed above incorporating the bridging member 144, which features of system 210 are numbered correspondingly to those features of system 10, except in the 200 series (e.g., 210 versus 10, etc.), and thus the corresponding descriptions will not be repeated herein. The coil device 214 differs from the coil device 14 of system 10 in the features of the retaining member of the coil device 214, which retaining member cooperates with the pull wire to retain the coil on the delivery shaft and to detach the coil from the delivery shaft. The embolic coil device 214 has an attached ball element 200 at its proximal end, which cooperates with the opening 206 of the bridging member 244 and the pull wire 230 to detachably connect the coil device 214 to the delivery shaft 222. Specifically, when the pull wire 230 has a portion that is longitudinally coextensive with the ball element 200 that is partially stuck in the opening 206, the ball element 200 remains partially stuck because the size of the ball element 200, the pull wire 230, and the shaft lumen 228 in this area will not allow the ball element 200 to move out of the window or opening 206 (the pull wire acts as a so-called "interference wire" in this arrangement). Separation of the coil device 214 from the shaft 222 can be achieved by retracting the pull wire 230 proximally until its distal end 232 is proximal to the ball element 200, thereby releasing the ball element to travel distally through the lumen 228 and out of the end 224 of the shaft 222.

[0056] In the illustrated embodiment, the ball element 200 is attached to a rod 202, which in turn is attached to an eyelet 204. A proximally located loop 218 formed of a filament material 220 is positioned through the eyelet 204. It should be understood that the filament material 220 is connected to the windings 216 of the coil device 214, as discussed above and elsewhere herein in conjunction with the windings 16 and filament material 20 of the coil device 14. It will also be understood that the system 210 can be used to deliver the coil device 214 to a target location and detach the coil device 214 at that location in a manner corresponding to the description of the system 10 and coil 14 herein.

[0057] The embolic coil system disclosed herein may have features of an embolic coil device and a condition in which it is detachably connected to a delivery shaft that facilitate reliable detachment of the coil device from the shaft. Figures 1 to 12 and the system 10 described in conjunction therewith, the embolic coil device 14 in a relaxed (unstressed) state (see, for example, Figure 8-10 ) has at least one segment 92, the windings 116 of the device in the segment 92 are open windings, wherein the surfaces of adjacent windings are longitudinally spaced apart from each other. This longitudinal spacing may be a distance 98 ( Fig. 9 ), in some forms, the distance may be equal to at least 10% of the diameter of the wire of winding 116, or at least 20% of the diameter, typically in the range of about 10% to about 200%, or about 20% to about 100% of the diameter. Additionally or alternatively, in a relaxed (longitudinally extended) state, adjacent windings of the coil windings in segment 92 may be spaced apart from each other by a distance in the range of about 0.0005 to about 0.15 mm. The splayed windings of coil arrangement 14 are configured to act as elastic, longitudinally compressible spring segments that can be longitudinally compressed to bring their adjacent surfaces into closer proximity, thereby shortening coil arrangement 14, and when released from such compression, the spring segments elastically stretch to move their adjacent surfaces away from each other and lengthen coil arrangement 14, e.g., the splayed windings elastically stretch at least toward their original splayed and spaced state, and possibly to their original splayed and spaced state.

[0058] To connect the coil device 14 to the shaft 22, the ring 18 can pass through the end 46 of the bridge member 44 that provides the end 24 of the shaft 22 and be forced proximally through the bridge wall lumen 82 to a position proximal to the bridge wall 58. This can cause the proximal end 16A of the coil winding 16 to first contact the distally facing surface 56 of the bridge member 44, whereupon continued proximal movement of the ring 18 elastically compresses the open windings in the segment 92 of the coil device. The distal end 32 of the pull wire 30 can then be moved distally through the ring 18 to connect the coil device 14 to the delivery shaft 22, wherein the open windings of the segment 92 are maintained in an elastically compressed state. In this detachably connected state, the proximal end 16A of the coil winding 116 exerts a proximally longitudinal force on the distal surface 56 of the bridge member 44. As described above, when the pull wire 30 is thereafter retracted proximally to release the loop 18 and thereby detach the coil device 14, the elastic expansion of the open windings of the segments 92 can cause the loop 18 to travel distally through the bridging wall lumen 82 and exit the end 24 of the delivery shaft 22. This can facilitate a more reliable detachment of the device 14 from the shaft 22. In a state where the embolic coil device 14 is detachably connected to the shaft 22, the distal end 32 of the pull wire 30 is located distal to the loop 18, preferably distal to the bridging wall 58, and even more preferably distal to the distal end 24 of the delivery shaft 22 (e.g., within the lumen defined by the coil windings 116). Additionally or alternatively, in some embodiments, the distal end 32 of the pull wire 30 can be retracted by at least about 1 mm or at least about 3 mm, typically within a range of about 1 mm to about 10 mm, to cause detachment of the embolic coil device 14. It should be understood that a corresponding embolic coil connection operation can be performed using a delivery shaft having other bridging members disclosed herein.

[0059] Any suitable length segments and positions of the open windings of the coil device 14 that works elastically as described above can be utilized. In the illustrated embodiment, a preferred arrangement is depicted in which the first, most proximal segment 90 of the coil device 14 has relatively closed windings 116 compared to the windings 116 of segment 92 (having adjacent windings that touch each other and / or having a smaller longitudinal spacing than the windings of segment 92). The proximally positioned relatively closed winding segment 90 facilitates a reliable interface between the proximal end 16A of the coil winding 116 and the distally facing surface 56 of the bridging member 44. The embolic coil device 14 shown also has a distal segment 94, which has a relatively closed winding 116 compared to the windings 116 of segment 92 (again, having adjacent windings that touch each other and / or having a smaller longitudinal spacing than the windings of segment 92). In other embodiments, all of the windings of the embolic coil device may be flared so that the entire length of the winding may participate in the elastic compression and extension functions described above, or the flared winding segments may be located more proximally or distally on the coil device 14 than is currently depicted, or a plurality of such flared winding segments may be provided by the coil device 14. Preferably, the coil device 14 includes such elastic flared winding segments (e.g., segments 92) in a region at or near the proximal end 16A of the coil winding 16 (e.g., the proximal end of the elastic flared winding segment is within about 10 mm of the proximal end 16A), e.g., wherein the proximal end of the elastic flared winding segment is at or spaced distally from the proximal end 16A by a distance of about 0.2 to about 10 mm, or in some forms about 0.5 to about 5 mm. The embolic coil device 14 also includes an element 96 , such as a spherical or hemispherical member, that is attached to the distal end 16B of the coil winding 16 and provides a smooth distal end for the device 14 .

[0060] The longitudinal length of the elastic open winding segment 92 or any other elastic open winding segment as described herein can be any suitable longitudinal length. In some forms, such a longitudinal length will be at least about 1 mm, or at least about 2 mm, typically in the range of about 1 mm to about 15 mm, more typically in the range of about 2 mm to about 8 mm.

[0061] Although the above discussion focuses on Figures 1 to 12 , but it will be understood that the combination Figures 13 to 17 Described system with alternative bridging member and Figures 18 to 21 The embolic coil device of system 210 may also be equipped with the elastically expanded winding features described above. Other systems within the scope of this specification may also include these features. Fig. 20 and Fig.21, it can be seen that the embolic coil device 214 includes a relatively closed winding segment 290, an open winding segment 292 and a relatively closed winding segment 94, corresponding to the combination Figures 1 to 12 During the separation of the coil device 214 from the shaft 222 of the system 210, as the distal end 232 of the pull wire 230 moves proximally past the ball element 200 to release it from the opening 206, the elastic expansion of the open windings of the segment 292 can cause the ball 200 to travel distally to leave the end 224 of the delivery shaft 222. Again, this can facilitate more reliable separation of the coil device 214 from the shaft 222.

[0062] refer to Figure 8 and Fig.10 In a preferred form of the coil assembly 14 and systems including the coil assembly 14, the filament 20 is connected to the coil winding 116 of the coil at a location 100 just distal to the distal end of the splayed winding segment 92 (e.g., within about 3 mm or within about 1 mm of the distal end of the splayed winding segment 92). For purposes of illustration, Figure 8 and Fig.10 The coil winding at position 100 is shown to be forced to elastically open, which can be achieved by applying an adhesive 102 or implementing another attachment of the filament 20 to the coil winding. It should be understood that the specific attachment form of the filament to the coil winding 116 can vary depending on the materials used in the filament 20 and / or the coil winding 116. For example, in various embodiments, the attachment can be achieved by solder or welding or an adhesive (such as an adhesive or glue). After the attachment is achieved, the winding at position 100 can be released to return to a more closed state. In other forms, the coil winding at position 100 can be in a relatively open state, such as Figure 8 and Fig.10Attaching the filament 20 to the coil winding at position 100 provides a feature in which the coil winding 116 distal to position 100 is not subject to the compressive forces discussed in conjunction with the load and detachable connection state of the coil device 14. This is because the proximal drive of the ring 18 pulls the coil winding 116 at position 100, but does not pull the coil winding 116 distal to position 100. In some embodiments, the filament 20 can terminate at position 100. In a preferred form, the filament continues to the distal end of the embolic coil device 14 and is also attached to the coil winding at position 104. Therefore, during a delivery operation before separation, for example, and / or after separation at the target site, the filament can provide tensile resistance for the embolic coil device 14 between positions 100 and 104. It should also be understood that when the embolic coil device is in a detachably connected state (e.g., during manipulation to or coil delivery at a target site), the segment of the filament 20 extending between location 100 and the loop 18 will provide stretch resistance to the length of the coil device 14 located proximal to location 100.

[0063] It should be understood that the attachment features of the filament 20 to the coil winding 116 of the embolic coil device 14 discussed above may also be incorporated into the Figures 13 to 17 A coil delivery system with an alternative bridging member is described. Figures 18 to 21 In the system 210 and other systems within the scope described herein, the attachment features include protecting the coil windings distal to the attachment location 100 from compressive forces and / or providing stretch resistance through the filament 20.

[0064] The delivery system 10, 210 described herein can be used to deliver the coil device 14, 214 to an aneurysm in a blood vessel. When doing so, a catheter 300 (e.g., a microcatheter) can be located within the blood vessel so that its distal end 302 is placed within the aneurysm. Then, the delivery system 10, 210 including the delivery shaft 22, 222 and the detachably connected coil device 14, 214 is advanced through the catheter 300. The system 10, 210 can be preloaded in an introducer sheath, etc. (not shown). Then the system 10, 210 advances to place the coil device 14, 214 in the aneurysm. One or more radiopaque markers located on the delivery system 10, 210 and / or the catheter 300 can be used to help the physician locate the system 10, 210 so as to deploy the coil device 14, 214. The coil device 14, 214 can then be released into the aneurysm by retracting the proximal side of the pull wire 30, 230. Where the system 10 , 210 includes an arrangement for preventing accidental release of the coil device 14 , 214 as described above, the shaft 22 , 222 is broken at location 40 by applying a bending force to the shaft 22 , 222 at location 40 prior to proximal retraction of the puller wire 30 , 230 .

[0065] List of some of the embodiments herein

[0066] A non-limiting enumerable list of specific embodiments herein is provided below.

[0067] 1. A system for delivering an embolic coil device, the system comprising:

[0068] a flexible elongated delivery shaft having a distal region;

[0069] an embolic coil device detachably connected to the distal region of the elongated delivery shaft, wherein the coil windings of the embolic coil device are in a resilient longitudinally compressed state;

[0070] Therein, upon detachment of the embolic coil device from the elongated delivery shaft, the coil windings are elastically moved to a longitudinally extended state, wherein the coil windings are more open in the longitudinally extended state than they are in an elastically longitudinally compressed state.

[0071] 2. A system according to embodiment 1, wherein the embolic coil device is detachably connected to the distal region by a retaining member of the embolic coil device, and the retaining member interacts with a pull wire extending through the lumen of the slender delivery shaft, wherein proximal retraction of the pull wire causes the embolic coil device to separate from the slender delivery shaft.

[0072] 3. A system according to embodiment 2, wherein the retaining member includes a ball and the delivery shaft defines a ball receiving opening, wherein the ball is retained in the window by a pull wire until the proximal side is retracted.

[0073] 4. A system according to embodiment 3, wherein the ball is attached to a filament extending into the lumen of the embolic coil device, preferably, wherein the filament provides stretch resistance to the embolic coil device at least prior to the detachment.

[0074] 5. A system according to embodiment 2, wherein the retaining member includes a ring and the pull wire extends through the ring.

[0075] 6. A system according to embodiment 5, wherein the ring is defined by a filament extending into the lumen of the embolic coil device, preferably, wherein the filament provides stretch resistance to the embolic coil device at least prior to the detachment.

[0076] 7. The system according to any of the preceding embodiments, wherein the winding is a first winding segment, the first winding segment comprising only a portion of a coil winding of an embolic coil device.

[0077] 8. The system of embodiment 7, wherein the first winding segment is located in a proximal region of the embolic coil device.

[0078] 9. A system according to embodiment 7 or 8, wherein the side of the first winding segment has a flank winding segment located proximal to the first winding segment, wherein the flank winding segment has a relatively closed coil winding compared to the first winding segment.

[0079] 10. A system according to embodiment 7 or 8, wherein the first winding segment has a flank winding segment located distally from the first winding segment on its side, wherein the flank winding segment has a relatively closed coil winding compared to the first winding segment.

[0080] 11. A system according to embodiments 7 or 8, wherein the side of the first winding segment has a second winding segment located proximal to the first winding segment and a third winding segment located distal to the first winding segment, wherein both the second winding segment and the third winding segment have relatively closed coil windings compared to the first winding segment.

[0081] 12. A system according to embodiment 10, wherein the wing winding segment extends from a distal end of the first winding segment to a distal end of the coil winding of the embolic coil device.

[0082] 13. A system according to embodiment 11, wherein the third winding segment extends from the distal end of the first winding segment to the distal end of the coil winding of the embolic coil device.

[0083] 14. The system of any one of embodiments 7 to 13, wherein the first winding segment has a length of at least about 1 mm or in a range of about 1 mm to about 15 mm.

[0084] 15. The system of any one of embodiments 1 to 6, wherein the coil windings include all coil windings of an embolic coil device.

[0085] 16. A system according to any one of embodiments 1 to 6 or 15, wherein adjacent windings of the coil winding in a longitudinally extended state are spaced apart from each other by a distance equal to at least 10% of the diameter of the wire forming the coil winding, and more preferably at least 20% of the diameter.

[0086] 17. A system according to any one of embodiments 1 to 6 and 15 to 16, wherein adjacent windings of the coil windings in a longitudinally extended state are longitudinally spaced apart from each other by a distance in the range of about 0.0005 mm to about 0.15 mm.

[0087] 18. A system according to any one of embodiments 7 to 14, wherein adjacent windings of the coil winding in a longitudinally extended state in the first winding segment are spaced apart from each other by a distance equal to at least 10% of the diameter of the wire forming the coil winding, and more preferably at least 20% of the diameter.

[0088] 19. A system according to any one of embodiments 7 to 14 and 18, wherein adjacent windings of the coil windings in the first winding segment in a longitudinally extended state are longitudinally spaced apart from each other by a distance in the range of about 0.0005 to about 0.15 mm.

[0089] 20. An embolic coil device for detachably attaching to an elongated delivery shaft of an embolic coil delivery system, the embolic coil device comprising:

[0090] a coil winding having a longitudinally extended state in a relaxed state of the embolic coil device, the coil winding being resiliently compressible to a longitudinally compressed state for attachment to the shaft and configured to resiliently move to or toward the longitudinally extended state when separated from the shaft, wherein the coil winding is more open in the longitudinally extended state than in the longitudinally compressed state; and

[0091] A retaining member is attached to the coil winding and is configured to cooperate with the shaft in a detachable connection of the embolic coil device to the shaft.

[0092] 21. The device of embodiment 20, wherein the retaining member comprises a ball.

[0093] 22. The device of embodiment 21, wherein the ball is attached to a filament extending into a lumen of the embolic coil device, preferably wherein the filament is configured to provide stretch resistance to the embolic coil device at least prior to the detachment.

[0094] 23. The device of embodiment 20, wherein the retaining member comprises a ring.

[0095] 24. The device of embodiment 23, wherein the loop is defined by a filament extending into the lumen of the embolic coil device, preferably wherein the filament is configured to provide stretch resistance to the embolic coil device at least prior to the detachment.

[0096] 25. The device of any one of embodiments 20 to 24, wherein the winding is a first winding segment comprising only a portion of a coil winding of an embolic coil device.

[0097] 26. The device of embodiment 25, wherein the first winding segment is located in a proximal region of the embolic coil device.

[0098] 27. An apparatus according to embodiments 25 or 26, wherein the flank winding segment of the first winding segment is located proximal to the first winding segment, wherein the flank winding segment located proximal to the first winding segment has a relatively closed coil winding compared to the first winding segment.

[0099] 28. An apparatus according to embodiments 25 or 26, wherein the flank winding segment of the first winding segment is located distally of the first winding segment, wherein the flank winding segment distally of the first winding segment has a relatively closed coil winding compared to the first winding segment.

[0100] 29. An apparatus according to embodiments 25 or 26, wherein the side of the first winding segment has a second winding segment located proximal to the first winding segment and a third winding segment located distal to the first winding segment, wherein both the second winding segment and the third winding segment have relatively closed coil windings compared to the first winding segment.

[0101] 30. The device of embodiment 28, wherein the wing winding segment extends from a distal end of the first winding segment to a distal end of the coil winding of the embolic coil device.

[0102] 31. The device of embodiment 29, wherein the third winding segment extends from a distal end of the first winding segment to a distal end of the coil winding of the embolic coil device.

[0103] 32. An apparatus according to any one of embodiments 25 to 31, wherein the first winding segment has a length of at least about 1 mm or in the range of about 1 mm to about 15 mm.

[0104] 33. The device of any one of embodiments 20 to 24, wherein the coil windings comprise all coil windings of an embolic coil device.

[0105] 34. An apparatus according to any one of embodiments 20 to 24 or 33, wherein adjacent windings of the coil winding in a longitudinally extended state are longitudinally spaced apart from each other by a distance equal to at least 10% of the diameter of the wire forming the coil winding, and more preferably equal to at least 20% of the diameter.

[0106] 35. A device according to any one of embodiments 20 to 24 and 33 to 34, wherein adjacent windings of the coil windings in a longitudinally extended state are longitudinally spaced apart from each other by a distance in the range of about 0.0005 to about 0.15 mm.

[0107] 36. An apparatus according to any one of embodiments 25 to 32, wherein adjacent windings of the coil winding in a longitudinally extended state in the first winding segment are longitudinally spaced apart from each other by a distance equal to at least 10% of the diameter of the wire forming the coil winding, and more preferably equal to at least 20% of the diameter.

[0108] 37. A device according to any one of embodiments 25 to 32 and 36, wherein adjacent windings of the coil windings in the first winding segment in a longitudinally extended state are longitudinally spaced apart from each other by a distance in the range of about 0.0005 to about 0.15 mm.

[0109] 38. A system according to any one of embodiments 2 to 19, wherein the slender delivery shaft has a coil separation interface at a distal region of the flexible slender delivery shaft, the coil separation interface comprising a distal tubular segment and a bridging segment proximal to the distal tubular segment, optionally wherein the bridging segment comprises a bridging wall defining an upper surface and a lower surface, the bridging segment defining a lumen between the lower surface of the bridging wall and the bottom wall of the bridging segment.

[0110] 39. A system according to embodiment 38, wherein the bridging wall defines a proximally facing edge spanning between the upper surface and the lower surface and a distally facing edge spanning between the upper surface and the lower surface.

[0111] 40. A system according to embodiment 38 or 39, wherein the bridging wall is generally planar or defines at least one curved wall portion and / or wherein the longitudinal cross-section of the bridging wall is rectangular in shape.

[0112] 41. A system according to any one of embodiments 38 to 40, wherein the bridging wall defines a first curved portion and a second curved portion.

[0113] 42. A system according to embodiment 41, wherein the first curved portion and the second curved portion each define a concave surface of the lower surface of the bridging wall and a corresponding convex surface of the upper surface of the bridging wall.

[0114] 43. A system according to embodiment 42, wherein the bridging wall defines a third curved portion, and the third curved portion is located between the first curved portion and the second curved portion and connects the first curved portion and the second curved portion.

[0115] 44. A system according to embodiment 43, wherein the third curved portion defines a convex surface of the lower surface of the bridging wall and a corresponding concave surface of the upper surface of the bridging wall.

[0116] 45. A system according to any one of embodiments 38 to 44, wherein the bridging wall extends substantially perpendicular to the longitudinal axis of the slender delivery shaft.

[0117] 46. ​​A system according to any one of embodiments 38 to 45, wherein the slender delivery shaft includes a bridging member attached to the distal end of a section of tube (preferably a metal sea wave tube), wherein the bridging member provides a distal tubular segment and a bridging segment of the coil separation interface; optionally, wherein the bridging member includes a bridging component, which extends transversely to the longitudinal axis of the bridging member and defines at least one side wall opening, the side wall opening having an opening portion appearing proximal to the proximal surface of the bridging component; and / or optionally, wherein the delivery shaft has a shaft segment in a proximal region of the delivery shaft, the shaft segment being configured to selectively disconnect and separate the delivery shaft at the shaft segment in response to a bending force applied to the shaft segment, and the pull wire is attached to the delivery shaft at a position proximal to the shaft segment.

[0118] 47. A system according to embodiment 46, wherein the bridging segment is an intermediate segment of a bridging member, and the bridging member also includes a tubular segment proximal to the bridging segment and defining a proximal-facing circumferential surface, wherein the bridging member is attached to the distal end of the segment of tube (preferably a metal sea wave tube) at the proximal-facing circumferential surface.

[0119] 48. A system according to embodiment 46 or 47, wherein the bridging member is a unitary structure formed by a single section of tube.

[0120] 49. The system of any one of embodiments 38 to 48, wherein the retaining member comprises a ball at the proximal end of the embolic coil device.

[0121] 50. A system as described in embodiment 49, wherein the slender delivery shaft defines a ball receiving opening, wherein the ball is retained in the ball receiving opening by a pull wire until the proximal side of the pull wire is retracted.

[0122] 51. A system according to any one of embodiments 46 to 48, wherein the retaining member includes a ball at the proximal end of the embolic coil device, wherein the distal tubular segment of the bridging member defines a ball receiving opening, and wherein the ball is retained in the ball receiving opening by a pull wire until the proximal end of the pull wire is retracted.

[0123] 52. A system according to embodiment 51, wherein the ball receiving opening is defined in the side wall of the distal tubular segment of the bridging member.

[0124] 53. A system according to any one of embodiments 38 to 52, wherein the pull wire extends in a path above the upper surface of the bridging wall.

[0125] 54. The system of any one of embodiments 38 to 48, wherein the retaining member comprises a ring attached to the embolic coil.

[0126] 55. The system of embodiment 54 wherein the pull wire extends through the loop until the proximal side of the pull wire translates.

[0127] 56. A system according to embodiment 55, wherein the proximal end of the loop is maintained at a position proximal to a bridging member until the proximal side of the pull wire translates, and the bridging member is preferably a bridging wall.

[0128] 57. A system according to embodiment 56, wherein the retaining member extends through the tubular cavity defined by the bridging segment and the pull wire extends in a path through the ring and then over the upper surface of the bridging wall.

[0129] 58. A system according to any one of embodiments 38 to 57, wherein the distal tubular segment has a distal-most end defining a full circumferential surface facing distally, wherein the proximal end of the coil winding of the embolic coil device is adjacent to the full circumferential surface facing distally.

[0130] 59. A system according to any one of embodiments 38 to 58, wherein the pull wire has a distal end located distal to a bridge member, and the bridge member is preferably a bridge wall.

[0131] 60. The system of embodiment 59, wherein the distal end of the pull wire is located distal to the distal tubular segment.

[0132] 61. A system for delivering an embolic coil device, comprising:

[0133] a flexible, elongated delivery shaft defining a lumen and having a distal region;

[0134] A coil separation interface located at a distal region of a flexible elongated delivery shaft and comprising a distal tubular segment and a bridging segment proximal to the distal tubular segment, the bridging segment comprising a bridging wall or other bridging member defining an upper surface and a lower surface, the bridging segment defining a lumen between a lower surface of the bridging wall or other bridging member and a bottom wall of the bridging segment; optionally, wherein the bridging segment defines a sidewall opening having an opening portion that appears proximal to a proximal surface of the bridging wall or other bridging member;

[0135] an embolic coil device detachably connected to the distal region of the elongated delivery shaft;

[0136] a pull wire extending through the lumen of the elongated delivery shaft and interacting with a retaining member of the embolic coil device;

[0137] Therein, proximal retraction of the pull wire causes the embolic coil device to separate from the elongated delivery shaft.

[0138] 62. A system according to embodiment 61, wherein the bridging wall defines a proximally facing edge spanning between the upper surface and the lower surface and a distally facing edge spanning between the upper surface and the lower surface.

[0139] 63. A system according to embodiment 61 or 62, wherein the bridging wall is generally planar or defines at least one curved wall portion.

[0140] 64. A system according to embodiment 61 or 62, wherein the bridging wall defines a first curved portion and a second curved portion.

[0141] 65. A system according to embodiment 64, wherein the first curved portion and the second curved portion each define a concave surface of the lower surface of the bridging wall and a corresponding convex surface of the upper surface of the bridging wall.

[0142] 66. A system according to embodiment 65, wherein the bridging wall defines a third curved portion, and the third curved portion is located in the middle of the first curved portion and the second curved portion and connects the first curved portion and the second curved portion.

[0143] 67. A system according to embodiment 66, wherein the third curved portion defines a convex surface of the lower surface of the bridging wall and a corresponding concave surface of the upper surface of the bridging wall.

[0144] 68. A system according to any one of embodiments 61 to 67, wherein the bridging wall extends substantially perpendicular to the longitudinal axis of the slender delivery shaft.

[0145] 69. A system according to any one of embodiments 61 to 68, wherein the slender delivery shaft includes a bridging member attached to the distal end of a section of tube, the tube optionally being a metal sea wave tube, wherein the bridging member provides a distal tubular segment and a bridging segment of the coil separation interface; optionally, wherein the delivery shaft has an axis segment in a proximal region of the delivery shaft, the axis segment being configured to selectively disconnect and separate the delivery shaft at the axis segment in response to a bending force applied to the axis segment, and a pull wire is attached to the delivery shaft at a position proximal to the axis segment.

[0146] 70. A system according to embodiment 69, wherein the bridging segment is an intermediate segment of a bridging member, and the bridging member also includes a tubular segment proximal to the bridging segment and defining a proximal-facing circumferential surface, wherein the bridging member is attached to the distal end of the segment of the tube at the proximal-facing circumferential surface, and the tube is preferably a metal sea wave tube.

[0147] 71. A system according to embodiment 69 or 70, wherein the bridging member is a unitary structure formed by a single section of tube.

[0148] 72. The system of any one of embodiments 61 to 71, wherein the retaining member comprises a ball at the proximal end of the embolic coil device.

[0149] 73. A system according to embodiment 72, wherein the slender delivery shaft defines a ball receiving opening, wherein the ball is retained in the ball receiving opening by a pull wire until the proximal side of the pull wire is retracted.

[0150] 74. A system according to one of embodiments 69 to 71, wherein the retaining member includes a ball at the proximal end of the embolic coil device, wherein the distal tubular segment of the bridging member defines a ball receiving opening, wherein the ball is retained in the ball receiving opening by a pull wire until the proximal end of the pull wire is retracted.

[0151] 75. The system of embodiment 74, wherein the ball receiving opening is defined in a sidewall of a distal tubular segment of the bridging member.

[0152] 76. The system of any one of embodiments 61 to 75, wherein the pull wire extends in a path above an upper surface of the bridging wall.

[0153] 77. The system of any one of embodiments 61 to 71, wherein the retention member comprises a ring attached to the embolic coil.

[0154] 78. The system of embodiment 77 wherein the pull wire extends through the loop until the proximal side of the pull wire translates.

[0155] 79. The system of embodiment 78, wherein the proximal end of the loop is maintained at a position proximal to the bridging wall until the proximal end of the pull wire is translated.

[0156] 80. The system of embodiment 79 wherein the retaining member extends through a lumen defined by the bridging segment and the pull wire extends in a path through the ring and then over an upper surface of the bridging wall.

[0157] 81. A system according to any one of embodiments 61 to 80, wherein the distal tubular segment has a distal-most end defining a full circumferential surface facing distally, wherein the proximal end of the coil winding of the embolic coil device is adjacent to the full circumferential surface facing distally.

[0158] 82. The system of any one of embodiments 61 to 81, wherein the pull wire has a distal end located distal to the bridging wall.

[0159] 83. The system of embodiment 82, wherein the distal end of the pull wire is located distal to the distal tubular segment.

[0160] 84. A bridging member for use in a separation interface of an embolic coil device delivery system, comprising:

[0161] A distal tubular segment, a proximal tubular segment, and an intermediate segment between the distal tubular segment and the proximal tubular segment, wherein (i) the intermediate segment includes a bridging wall defining an upper surface and a lower surface, and the intermediate segment defines a lumen between the lower surface of the bridging wall and the bottom wall of the bridging segment; or (ii) the intermediate segment includes a bridging component extending transversely to the longitudinal axis of the bridging member, and the intermediate segment defines at least one side wall opening, the side wall opening having an opening portion present near the proximal side of the proximal surface of the bridging component, preferably, wherein (a) the at least one The invention relates to a method for preparing an embodiment of the present invention wherein: (a) the at least one side wall opening has a maximum width in a direction perpendicular to the longitudinal axis of the bridging member, the maximum width being at least 40% of the corresponding width of the bridging member extending longitudinally together with the at least one side wall opening, (b) the at least one side wall opening has a maximum length in the direction of the longitudinal axis of the bridging member, the maximum length being at least equal to the maximum width of the at least one side wall opening, and / or (c) the longitudinal proximal distance between the opening portion and the proximal surface of the bridging member is no greater than 200% of the corresponding width of the bridging member extending longitudinally together with the at least one opening.

[0162] 85. A bridging member according to embodiment 84, wherein the bridging wall defines a proximally facing edge spanning between the upper surface and the lower surface and a distally facing edge spanning between the upper surface and the lower surface.

[0163] 86. A bridging member according to embodiment 84, wherein the bridging wall is generally planar or defines at least one curved wall portion.

[0164] 87. A bridging member according to embodiment 84 or 85, wherein the bridging wall defines a first curved portion and a second curved portion.

[0165] 88. A bridging member according to embodiment 87, wherein the first curved portion and the second curved portion each define a concave surface of the lower surface of the bridging wall and an opposite convex surface of the upper surface of the bridging wall.

[0166] 89. A bridging member according to embodiment 88, wherein the bridging wall defines a third curved portion, and the third curved portion is located in the middle of the first curved portion and the second curved portion and connects the first curved portion and the second curved portion.

[0167] 90. A bridging member according to embodiment 89, wherein the third curved portion defines a convex surface of the lower surface of the bridging wall and a corresponding concave surface of the upper surface of the bridging wall.

[0168] 91. A bridging member according to any one of embodiments 84 to 90, wherein the bridging wall extends generally perpendicular to the longitudinal axis of the bridging member.

[0169] 92. A flexible, elongated delivery shaft in a system for delivering an embolic coil device, comprising a bridging member according to any one of embodiments 84 to 91, the bridging member being attached to a distal end of a length of tubing, preferably a metal hypotube.

[0170] 93. A flexible, elongated delivery shaft according to embodiment 92, having a shaft segment in a proximal region of the delivery shaft, wherein the shaft segment is configured to selectively break and separate the delivery shaft at the shaft segment in response to a bending force applied at the shaft segment.

[0171] 94. The flexible, elongated delivery shaft of embodiment 92, in combination with a pull wire extending through the lumen of the elongated delivery shaft; and optionally also in combination with a coil device detachably connected to the flexible, elongated delivery shaft.

[0172] 95. A combination according to embodiment 94, wherein the delivery shaft has an axis segment in a proximal region of the delivery shaft, and the axis segment is configured to selectively disconnect and separate the delivery shaft at the axis segment in response to a bending force applied to the axis segment, wherein the pull wire is attached to the delivery shaft at a position proximal to the axis segment.

[0173] 96. The system of any one of embodiments 61 to 83, wherein:

[0174] The embolic coil device has a coil winding of the embolic coil device in a resilient longitudinally compressed state;

[0175] Upon detachment of the embolic coil device from the elongated delivery shaft, the coil windings are elastically moved to a longitudinally extended state, wherein the coil windings are more open in the longitudinally extended state than they are in the elastically longitudinally compressed state.

[0176] 97. The system of embodiment 96, wherein the winding is a first winding segment comprising only a portion of a coil winding of an embolic coil device.

[0177] 98. The system of embodiment 97, wherein the first winding segment is located in a proximal region of the embolic coil device.

[0178] 99. A system according to embodiment 97 or 98, wherein the side of the first winding segment has a flank winding segment located proximal to the first winding segment, wherein the flank winding segment located proximal to the first winding segment has a relatively closed coil winding compared to the first winding segment.

[0179] 100. A system according to embodiment 97 or 98, wherein the side of the first winding segment has a flank winding segment located distally of the first winding segment, wherein the flank winding segment located distally of the first winding segment has a relatively closed coil winding compared to the first winding segment.

[0180] 101. A system according to embodiment 97 or 98, wherein the side of the first winding segment has a second winding segment located proximal to the first winding segment and a third winding segment located distal to the first winding segment, wherein both the second winding segment and the third winding segment have relatively closed coil windings compared to the first winding segment.

[0181] 102. A system according to embodiment 100, wherein a flank winding segment located distal to the first winding segment extends from a distal end of the first winding segment to a distal end of the coil winding of the embolic coil device.

[0182] 103. The system of embodiment 101, wherein the third winding segment extends from a distal end of the first winding segment to a distal end of the coil winding of the embolic coil device.

[0183] 104. A system according to any one of embodiments 97 to 103, wherein the first winding segment has a length of at least 1 mm or in a range of about 1 mm to about 15 mm.

[0184] 105. The system of embodiment 96, wherein the coil windings comprise all coil windings of an embolic coil device.

[0185] 106. A system according to any one of embodiments 96 to 105, wherein adjacent windings of the coil windings in a longitudinally extended state are spaced apart from each other by a distance equal to at least 10% of the diameter of the wire forming the adjacent coil windings, and more preferably equal to at least 20% of the diameter.

[0186] 107. A system according to any one of embodiments 96 to 106, wherein adjacent windings of the coil windings in a longitudinally extended state are spaced apart from each other by a distance in the range of about 0.005 to about 0.15 mm.

[0187] Unless otherwise specified herein or clearly contradictory to the context, the use of "one", "an" and "said" and similar references herein (particularly in the context of the appended claims) should be interpreted as covering the singular and plural. The description of the numerical range herein is merely a shorthand method for referring to each individual numerical value falling within the range, and unless otherwise specified herein, each individual numerical value is incorporated into the specification as if it were individually described. All methods described herein can be performed in any suitable order, unless otherwise specified herein or clearly contradictory to the context. Unless otherwise required, the use of any and all examples or exemplary language provided herein (e.g., "such as") is intended only to better illustrate the embodiments of the present disclosure and does not limit the scope of the present disclosure. Any language in the specification should not be interpreted as indicating that any unclaimed element is essential to the practice of the product or method defined by the claims.

[0188] While embodiments of the present disclosure have been illustrated and described in detail in the drawings and foregoing description, they are to be considered illustrative and not restrictive, and it is to be understood that only certain embodiments have been shown and described and that all changes and modifications that come within the spirit of the disclosure are desired to be protected.

Claims

1. A system for delivering an embolic coil device, the system comprising: a flexible elongated delivery shaft having a distal region; an embolic coil device detachably connected to the distal region of the elongated delivery shaft, wherein the coil windings of the embolic coil device are in a resilient longitudinally compressed state; Therein, upon detachment of the embolic coil device from the elongated delivery shaft, the coil windings are elastically moved to a longitudinally extended state, wherein the coil windings are more open in the longitudinally extended state than they are in an elastically longitudinally compressed state.

2. The system according to claim 1, wherein: The embolic coil device is detachably connected to the distal region via an embolic coil device retention member that interacts with a pull wire extending through the lumen of the elongated delivery shaft, wherein proximal retraction of the pull wire causes the embolic coil device to detach from the elongated delivery shaft.

3. The system according to claim 2, wherein: The retaining member includes a ball, the delivery shaft defines a ball receiving opening, wherein the ball is retained in the window by a pull wire until the proximal retraction.

4. The system according to claim 3, wherein: The ball is attached to a filament extending into the lumen of the embolic coil device, preferably wherein the filament provides stretch resistance to the embolic coil device at least prior to said detaching.

5. The system according to claim 2, wherein: The retaining member includes a loop through which the pull wire extends.

6. The system according to claim 5, wherein: The loop is defined by filaments extending into the lumen of the embolic coil device, preferably wherein the filaments provide stretch resistance to the embolic coil device at least prior to said detaching.

7. A system according to any one of the preceding claims, wherein: The winding is a first winding section which comprises only a portion of a coil winding of the embolic coil device.

8. The system according to claim 7, wherein: The first winding segment is located in a proximal region of the embolic coil device.

9. The system according to claim 7 or 8, wherein: A flank winding section is provided on a side of the first winding section and is located proximal to the first winding section, wherein the second winding section has a relatively closed coil winding compared to the first winding section.

10. The system according to claim 7 or 8, wherein: A flank winding segment is disposed on a side of the first winding segment and is located far from the first winding segment, wherein the flank winding segment has a relatively closed coil winding compared to the first winding segment.

11. The system according to claim 7 or 8, wherein: The first winding section has a second winding section located proximal to the first winding section and a third winding section located distal to the first winding section on its side, wherein both the second winding section and the third winding section have relatively closed coil windings compared to the first winding section.

12. The system according to claim 10, wherein: The wing winding segment extends from a distal end of the first winding segment to a distal end of the coil winding of the embolic coil device.

13. The system according to claim 11, wherein: The third winding segment extends from the distal end of the first winding segment to the distal end of the coil winding of the embolic coil device.

14. A system according to any one of claims 7 to 13, wherein: The first winding segment has a length of at least about 1 mm or in the range of about 1 mm to about 15 mm.

15. The system according to any one of claims 1 to 6, wherein: The coil windings include all coil windings of the embolic coil device.

16. A system according to any one of claims 1 to 6 or 15, wherein: Adjacent windings of the coil windings in the longitudinally extended state are spaced apart from each other by a distance equal to at least 10% of the diameter of the wire forming the coil windings, more preferably equal to at least 20% of said diameter.

17. The system according to any one of claims 1 to 6 and 15 to 16, wherein: Adjacent windings of the coil windings in the longitudinally extended state are longitudinally spaced apart from each other by a distance in the range of about 0.0005 mm to about 0.15 mm.

18. A system according to any one of claims 7 to 14, wherein: Adjacent windings of the coil windings in the first winding section in the longitudinally extending state are spaced apart from each other by a distance equal to at least 10% of the diameter of the wire forming the coil windings, more preferably equal to at least 20% of said diameter.

19. A system according to any one of claims 7 to 14 and 18, wherein: Adjacent windings of the coil windings in the first winding section in a longitudinally extending state are longitudinally spaced apart from each other by a distance in the range of about 0.0005 to about 0.15 mm.

20. An embolic coil device for detachably attaching to an elongated delivery shaft of an embolic coil delivery system, the embolic coil device comprising: a coil winding having a longitudinally extended state in a relaxed state of the embolic coil device, the coil winding being resiliently compressible to a longitudinally compressed state for attachment to the shaft and configured to resiliently move to or toward the longitudinally extended state upon separation from the shaft, wherein the coil winding is more open in the longitudinally extended state than in the longitudinally compressed state; A retaining member is attached to the coil winding and is configured to cooperate with the shaft in a detachable connection of the embolic coil device to the shaft.

21. The device according to claim 20, wherein: The retaining member includes a ball.

22. The device according to claim 21, wherein The ball is attached to a filament extending into a lumen of the embolic coil device, preferably wherein the filament is configured to provide stretch resistance to the embolic coil device at least prior to said detaching.

23. The device according to claim 20, wherein: The retaining member includes a ring.

24. The device according to claim 23, wherein: The loop is defined by filaments extending into the lumen of the embolic coil device, preferably wherein the filaments are configured to provide stretch resistance to the embolic coil device at least prior to said detaching.

25. The device according to any one of claims 20 to 24, wherein The winding is a first winding section which comprises only a portion of a coil winding of the embolic coil device.

26. The device according to claim 25, wherein The first winding segment is located in a proximal region of the embolic coil device.

27. The device according to claim 25 or 26, wherein: A flank winding section is provided on a side of the first winding section and is located proximal to the first winding section, wherein the second winding section has a relatively closed coil winding compared to the first winding section.

28. The device according to claim 25 or 26, wherein: A flank winding segment is disposed on a side of the first winding segment and is located far from the first winding segment, wherein the flank winding segment has a relatively closed coil winding compared to the first winding segment.

29. The device according to claim 25 or 26, wherein: The first winding section has a second winding section located proximal to the first winding section and a third winding section located distal to the first winding section on its side, wherein both the second winding section and the third winding section have relatively closed coil windings compared to the first winding section.

30. The device according to claim 28, wherein The wing winding segment extends from a distal end of the first winding segment to a distal end of the coil winding of the embolic coil device.

31. The device according to claim 29, wherein: The third winding segment extends from the distal end of the first winding segment to the distal end of the coil winding of the embolic coil device.

32. The device according to any one of claims 25 to 31, wherein: The first winding segment has a length of at least about 1 mm or in the range of about 1 mm to about 15 mm.

33. The device according to any one of claims 20 to 24, wherein: The coil windings include all coil windings of the embolic coil device.

34. The device according to any one of claims 20 to 24 or 33, wherein: Adjacent windings of the coil windings in the longitudinally extended state are longitudinally spaced apart from each other by a distance equal to at least 10% of the diameter of the wire forming the coil windings, more preferably equal to at least 20% of said diameter.

35. The device according to any one of claims 20 to 24 and 33 to 34, wherein Adjacent windings of the coil windings in the longitudinally extended state are longitudinally spaced apart from each other by a distance in the range of about 0.0005 to about 0.15 mm.

36. The device according to any one of claims 25 to 32, wherein: Adjacent windings of the coil windings in the first winding section in the longitudinally extending state are longitudinally spaced apart from each other by a distance equal to at least 10% of the diameter of the wire forming the coil windings, more preferably equal to at least 20% of said diameter.

37. The device according to any one of claims 25 to 32 and 36, wherein Adjacent windings of the coil windings in the first winding section in a longitudinally extending state are longitudinally spaced apart from each other by a distance in the range of about 0.0005 to about 0.15 mm.

38. A system according to any one of claims 2 to 19, wherein: The slender delivery shaft has a coil separation interface at the distal region of the flexible slender delivery shaft, and the coil separation interface includes a distal tubular segment and a bridging segment proximal to the distal tubular segment, the bridging segment includes a bridging wall defining an upper surface and a lower surface, and the bridging segment defines a tubular cavity between the lower surface of the bridging wall and the bottom wall of the bridging segment.

39. The system of claim 38, wherein: The bridging wall defines a proximally facing edge spanning between the upper surface and the lower surface and a distally facing edge spanning between the upper surface and the lower surface.

40. The system of claim 38 or 39, wherein: The bridging wall is generally planar or defines at least one curved wall portion and / or wherein a longitudinal cross-section of the bridging wall is rectangular in shape.

41. A system according to any one of claims 38 to 40, wherein: The bridging wall defines a first curved portion and a second curved portion.

42. The system of claim 41, wherein: The first curved portion and the second curved portion each define a concave surface of a lower surface of the bridging wall and an opposing convex surface of an upper surface of the bridging wall.

43. The system of claim 42, wherein: The bridging wall defines a third curved portion that is intermediate and connects the first curved portion and the second curved portion.

44. The system of claim 43, wherein: The third curved portion defines a convex surface of the lower surface of the bridging wall and an opposing concave surface of the upper surface of the bridging wall.

45. A system according to any one of claims 38 to 44, wherein: The bridging wall extends generally perpendicular to the longitudinal axis of the elongated delivery shaft.

46. ​​A system according to any one of claims 38 to 45, wherein: The elongated delivery shaft comprises a bridging member attached to the distal end of a section of metal sea wave tube, wherein the bridging member provides a distal tubular segment and a bridging segment of the coil separation interface; optionally, wherein the delivery shaft has an axis segment in a proximal region of the delivery shaft, the axis segment being configured to selectively disconnect and separate the delivery shaft at the axis segment in response to a bending force applied at the axis segment, and a pull wire is attached to the delivery shaft at a position proximal to the axis segment.

47. The system of claim 46, wherein: The bridge segment is an intermediate segment of a bridge member, the bridge member further comprising a tubular segment proximal to the bridge segment and defining a proximally facing circumferential surface, wherein the bridge member is attached to the distal end of the section of metal hypotube at the proximally facing circumferential surface.

48. A system according to claim 46 or 47, wherein: The bridging member is a unitary structure formed from a single length of tubing.

49. A system according to any one of claims 38 to 48, wherein: The retaining member includes a ball at the proximal end of the embolic coil device.

50. The system of claim 49, wherein: The elongated delivery shaft defines a ball receiving opening, wherein the ball is retained in the ball receiving opening by the pull wire until the proximal side of the pull wire is retracted.

51. A system according to any one of claims 46 to 48, wherein: The retaining member includes a ball at a proximal end of the embolic coil device, wherein the distal tubular section of the bridging member defines a ball receiving opening, wherein the ball is retained in the ball receiving opening by a pull wire until the proximal end of the pull wire is retracted.

52. The system of claim 51, wherein: The ball receiving opening is defined in a sidewall of the distal tubular section of the bridge member.

53. A system according to any one of claims 38 to 52, wherein: The pull wire extends in a path above the upper surface of the bridging wall.

54. A system according to any one of claims 38 to 48, wherein: The retaining member includes a ring attached to the embolic coil.

55. The system of claim 54, wherein: The pull wire extends through the loop until the proximal side of the pull wire translates.

56. The system of claim 55, wherein: The proximal end of the loop remains in position proximal to the bridging wall until the proximal side of the pull wire is translated.

57. The system of claim 58, wherein: The retaining member extends through a lumen defined by the bridge segment and the pull wire extends in a path through the ring and then over the upper surface of the bridge wall.

58. A system according to any one of claims 38 to 57, wherein: The distal tubular section has a distal-most end defining a distally-facing full circumferential surface, wherein a proximal end of a coil winding of the embolic coil device abuts the distally-facing full circumferential surface.

59. A system according to any one of claims 38 to 58, wherein: The pull wire has a distal end located distal to the bridging wall.

60. The system of claim 59, wherein: The distal end of the pull wire is located distal to the distal tubular segment.

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