Implant delivery using a modified release mechanism and pull wire engagement.

Abstract

To provide example systems, implants, and methods associated with the same which generally include an embolic implant.SOLUTION: An embolic implant includes a detachment feature configured to engage and be released from a delivery member's engagement system. The engagement system can include a loop wire extending through an opening of the detachment feature, and a pull wire extending through the loop wire to secure the detachment feature to a delivery tube of the delivery member. The detachment feature can include a distal extension configured to engage a distal end of the pull wire to inhibit the pull wire from moving distally into the implant. The detachment feature can also include a sleeve to align the pull wire to the distal extension and / or provide friction force against the pull wire to inhibit longitudinal movement of the distal end of the pull wire.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates generally to implantable medical devices, and more particularly to an engagement and disengagement mechanism capable of securing an implantable medical device to a delivery system during delivery of the implant and releasing the implantable medical device from the delivery system. [Background Art]

[0002] Aneurysms can be treated endovascularly by delivering a therapeutic device to the aneurysm, filling the aneurysm sac with embolic material, and / or occluding the neck of the aneurysm to inhibit blood flow into the aneurysm. When filling the aneurysm sac, the embolic material may promote blood coagulation to form a thrombotic mass within the aneurysm. When treating the neck of an aneurysm without substantially filling the aneurysm sac, blood flow to the neck of the aneurysm is inhibited, inducing venous stasis within the aneurysm and facilitating the natural formation of a thrombotic mass within the aneurysm.

[0003] Some current treatments use multiple embolic coils and other embolic implants (e.g., braids) either to fill the aneurysm sac or to treat the opening at the neck of the aneurysm. The embolic implant is attached to a tubular delivery member and delivered to the aneurysm via a delivery catheter. During delivery, the embolic implant may be engaged to an implant engagement / deployment system of the delivery member (referred to interchangeably herein as an "engagement system" or "deployment system"). When the embolic implant is in place, the deployment system can release the implant, leaving the implant implanted and allowing the delivery member to be withdrawn. Some treatments utilize a mechanical engagement / deployment system that can be actuated by a physician to release the implant by pulling one or more wires or other elongated members, collectively referred to herein as "pull wires".

[0004] Some of the challenges associated with the delivery and deployment of embolic implants equipped with delivery members having a mechanical engagement system include premature release of the implant during navigation of tortuous anatomical structures and / or during the movement of the delivery member. Premature release may result from pushback from a densely packed treatment site. [Overview of the Initiative] [Problems that the invention aims to solve]

[0005] Therefore, there is a need for improved methods, devices, and systems to facilitate the implantation of embolic coils and other implants that face similar challenges. [Means for solving the problem]

[0006] Exemplary systems, implants, and associated methods generally including embolic implants such as embolic coils or tubular braids, including a release mechanism configured to engage with and release from an engagement system (deployment system) of a delivery member, are presented herein. The delivery member may include an elongated delivery tube, and the engagement system may include a pull wire extending through the delivery tube and a loop wire attached near the distal end of the delivery tube. To secure the implant to the delivery tube, the loop wire may be positioned through an opening in the release mechanism, and the distal end of the pull wire may be positioned through an opening in the loop wire. The release mechanism may include a distal extension configured to engage with the distal end of the pull wire and prevent the pull wire from moving distally into the implant. The release mechanism may also include a sleeve for aligning the pull wire with the distal extension and / or providing frictional force to the pull wire to prevent longitudinal movement of the distal end of the pull wire.

[0007] An exemplary system may include an elongated delivery tube, an embolization implant, a loop wire, and a pull wire. The elongated delivery tube may be configured to traverse a vascular structure. The elongated delivery tube extends along the longitudinal axis of the system. The embolization implant includes a detachment mechanism. The detachment mechanism may have a distal extension and a proximal opening. A loop wire may be attached to the delivery tube. The loop wire may extend through the proximal opening of the detachment mechanism. The pull wire may extend through the delivery tube, extend through the opening of the loop wire, and be prevented from moving distally by the distal extension of the detachment mechanism.

[0008] The detachment mechanism may further include a sleeve through which the pull wire extends. The sleeve can provide frictional force to the pull wire. The sleeve may further include an elastic material positioned around at least a portion of the opening of the sleeve. The elastic material can provide frictional force to the pull wire. The pull wire can extend through the opening of the sleeve. In addition, or instead of providing frictional force, the sleeve may be positioned to longitudinally align the pull wire with its distal extension.

[0009] The separation mechanism may have a distal portion including a distal extension and a proximal portion including a proximal opening. The proximal portion may have a proximal width that is greater than the distal width of the distal portion.

[0010] The embolization implant may include an embolization coil. The distal portion of the detachment mechanism may be located within the lumen of the embolization coil. The distal portion may include a distal extension. The proximal portion of the detachment mechanism may extend proximal to the proximal end of the embolization coil. The proximal portion may include a proximal opening.

[0011] The distal portion of the detachment mechanism may further include a distal opening. The embolic implant may further include stretch-resistant fibers that pass through the distal opening and extend through the lumen of the embolic coil to the distal end of the embolic coil. The stretch-resistant fibers may be effective in limiting the separation of the windings of the embolic coil when the embolic coil is under tension.

[0012] The detachment mechanism may have a first shoulder attached to the proximal end of the embolic coil and a second shoulder attached to the proximal end of the embolic coil. The first shoulder may be offset longitudinally with respect to the second shoulder.

[0013] Embolization implants may include tubular braids.

[0014] The elongated delivery tube may have a notch extending from the distal end to the proximal end of the delivery tube. The proximal portion of the detachment mechanism may be located within the notch.

[0015] The proximal opening of the separation mechanism may have a non-traumatic surface in contact with the loop wire.

[0016] The separation mechanism may have a substantially flat first surface and a second surface opposite the first surface. The distal extension may be positioned on the second surface.

[0017] The pull wire can be compressed longitudinally within the delivery tube.

[0018] An exemplary implant may include an embolization tube and a release mechanism. The embolization tube may have a lumen passing through it. The embolization tube may define the longitudinal axis of the implant. The release mechanism may include a sleeve having a distal portion extending into the lumen, a proximal portion extending proximally from the proximal end of the embolization tube, a proximal opening configured to receive a loop wire passing through it, and a longitudinal opening configured to receive a pull wire.

[0019] The detachment mechanism may further have a distal extension positioned distal to the sleeve and aligned longitudinally with the opening.

[0020] The sleeve may include elastic material in at least a portion of the area surrounding the opening.

[0021] An exemplary method for delivering an implant having a release mechanism may include one or more of the following steps, presented in no particular order, and the method may include additional steps not included herein. The distal end of the pull wire may be prevented from moving distally by pushing it into the distal extension of the release mechanism. An implant delivery system may be delivered via a vascular structure, the implant delivery system including an elongated delivery tube, an implant, and a pull wire. The pull wire may be pulled proximal to release the release mechanism from the delivery tube.

[0022] The method may further include traversing the implant delivery system through a tortuous vascular structure. The method may further include preventing longitudinal movement of the distal end of the pull wire relative to the release mechanism by providing a sleeve that provides frictional force to the pull wire.

[0023] The method may further include aligning the distal end of the pull wire with the distal extension of the separation mechanism by means of a sleeve positioned on the separation mechanism and through which the pull wire extends.

[0024] Pulling the pull wire proximally, thereby releasing the disconnection mechanism from the delivery tube, may further include pulling the pull wire proximally so that it exits the loop of the loop wire attached to the delivery tube, thereby causing the loop wire to exit through the opening of the disconnection mechanism and disengage the disconnection mechanism from the delivery tube. [Brief explanation of the drawing]

[0025] The foregoing and further aspects of the present invention will be further considered with reference to the following description taken in conjunction with the accompanying drawings, in which like numerals indicate like structural elements and features in the various drawings. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the invention. The figures depict one or more implementations of the device of the present invention by way of example only, not by way of limitation. [Figure 1] It is a cross-sectional view of an implant attached to a delivery member according to an aspect of the present invention. [Figure 2] It is a side view of a detachment mechanism according to an aspect of the present invention. [Figure 3A] It is a view of a sleeve of a detachment mechanism according to an aspect of the present invention. [Figure 3B] It is a view of a sleeve of a detachment mechanism according to an aspect of the present invention. [Figure 3C] It is a view of a sleeve of a detachment mechanism according to an aspect of the present invention. [Figure 4A] It is a view of a distal extension of a detachment mechanism according to an aspect of the present invention. [Figure 4B] It is a view of a distal extension of a detachment mechanism according to an aspect of the present invention. [Figure 5] It is a view showing dimensions of an implant detachment mechanism according to an aspect of the present invention. [Figure 6] It is a cross-sectional view of an implant attached to a delivery member using a pull wire under compression, according to an aspect of the present invention. [Figure 7] It is a view of a system including an implant and a delivery member navigating through vasculature according to an aspect of the present invention. [Figure 8A] It is a series of views showing detachment of an implant from a delivery member according to an aspect of the present invention. [Figure 8B] It is a series of views showing detachment of an implant from a delivery member according to an aspect of the present invention. [Figure 8C] It is a series of views showing detachment of an implant from a delivery member according to an aspect of the present invention. [Figure 8D]This is a series of diagrams showing the separation of the implant from the delivery member according to an aspect of the present invention. [Figure 9A] This is a diagram of an alternative implant attached to a delivery system according to an aspect of the present invention. [Figure 9B] This is a diagram of an alternative implant attached to a delivery system according to an aspect of the present invention. [Figure 10] This is a flowchart illustrating an exemplary method for delivering and releasing an implant according to an aspect of the present invention. [Modes for carrying out the invention]

[0026] As used herein, the terms “about” or “approximately” for any number or range of numbers indicate a suitable dimensional tolerance that enables a part or set of components to function in accordance with its intended purpose as described herein. More specifically, “about” or “approximately” may refer to a range of values ​​within ±20% of the listed values, for example, “about 90%” may refer to a range of values ​​between 71% and 99%.

[0027] As used herein, the terms “tubular” and “tube” are to be interpreted broadly and are not limited to structures with a right cylindrical cross-section, a strictly circular cross-section, or a uniform cross-section along its entire length. For example, tubular structures or tubular systems are generally illustrated as substantially right cylindrical structures. However, tubular systems may have tapered or curved outer surfaces without departing from the scope of the present invention.

[0028] Systems, implants, and methods capable of achieving more accurate and repeatable implant detachment are disclosed herein. This may facilitate the placement of embolization coils and other implants facing challenges such as partially implanted implants that are difficult to reposition, shifted delivery systems due to pushback during implantation, and / or prematurely released implants. To satisfy some or all of these needs, exemplary implants may include a detachment mechanism having a proximal sleeve from which a pull wire can be extended and / or a distal extension that can engage with the distal end of the pull wire. The proximal sleeve may be configured in terms of size, position, and other ways to align the pull wire with the distal extension, and / or the proximal sleeve may provide frictional force to the pull wire. Preferably, the proximal sleeve provides friction from a disc or tab positioned to push the pull wire. The disc or tab may include a biocompatible material, preferably elastic. The distal extension may provide a hard stop to prevent the distal end of the pull wire from moving further into the implant. The distal extension is preferably hemispherical or conical. The sleeve and distal extension can be formed, respectively, by milling the material of the detachment mechanism and / or by attaching the material to the detachment mechanism. Preferably, the detachment mechanism can be laser-cut from a flat sheet material. The flat sheet material is preferably a radiopaque material that can be welded or otherwise attached to the embolic coil, braided tube, or other embolic structure of the implant by any suitable means.

[0029] Figure 1 is a cross-sectional view of the implant 10 attached to the delivery member 300. The implant 10 includes an embolization coil 12, a release mechanism 18, and a stretch-resistant fiber 16. A proximal weld 42 joins the proximal end 15 of the embolization coil 12 to the release mechanism 18. A distal weld 44 joins the distal end 14 of the embolization coil 12 to the stretch-resistant fiber 16. The coil 12, welds 42 and 44, and a portion of the delivery tube 302 are shown in the cross-sectional view for illustrative purposes.

[0030] The detachment mechanism 18 may include a distal opening 24 through which a stretch-resistant wire 16 is looped, a proximal opening 22 through which a loop wire 400 extends, a sleeve 29 through which a pull wire 140 extends, and a distal extension 35 positioned to engage with the distal end of the pull wire 140. The detachment mechanism 18 may include a bridge 28 positioned between the distal opening 24 and the proximal opening 22 to which the sleeve 29 is attached. The pull wire 140 extends through the loop opening 405 of the loop wire 400 so that the detachment mechanism 18 can be fixed to the delivery member 300. The loop wire 400 extends through the lumen of the delivery tube 302 of the delivery member 300 and can be subjected to tension, thereby compressing the distal portion of the delivery tube 302 having a helical notch 306.

[0031] Exemplary delivery members and engagement / deployment systems are described in U.S. Patents 10,806,461 and 10,806,462, which are incorporated herein by reference, respectively.

[0032] Figure 2 is a side view of the detachment mechanism 18, the loop wire 400, and the pull wire 140. For illustrative purposes, the embolization coil 12 and the delivery tube 302 are omitted. The detachment mechanism 18 may have a substantially flat profile, which provides flexibility in the in-page and out-of-page directions with respect to the orientation shown in Figure 1. The detachment mechanism 18 may have a flat rear surface 19 and a front surface 21 opposite the flat rear surface 19. The distal extension 35 and the sleeve 29 are located on the front surface 21.

[0033] The distal extension 35, sleeve 29, and / or bridge 28 can each facilitate the reduction of instances of premature deployment. The detachment mechanism 18 may include any combination of these mechanisms.

[0034] The bridge 28 may be positioned distal to the proximal opening 22. When the loop wire 400 is pushed into the pull wire 140 at the proximal opening 22 of the release mechanism 18, the pull wire 140 can bend accordingly. The bridge 28 can provide an opposing force to support the pull wire 140 and provide a limit to how much the pull wire 140 can bend.

[0035] The sleeve 29 can provide frictional force to the pull wire 140 to prevent the longitudinal movement of the pull wire 140. Preferably, the sleeve is positioned on the bridge 28. However, the sleeve can alternatively be positioned proximal 52 relative to the proximal opening 22, or distal 54 relative to the distal opening 24. If the detachment mechanism 18 includes a distal extension 35 and the sleeve 29, the sleeve can function to align the pull wire 140 with the distal extension 35, in which case the sleeve 29 may or may not also provide frictional force to the pull wire 140 to prevent its longitudinal movement.

[0036] The distal extension 35 is preferably located at the distal end of the detachment mechanism 18, thereby allowing the pull wire 140 to have a maximum extension through the loop opening 405 of the loop wire 400 without reducing the flexibility of the embolic coil 12.

[0037] To facilitate the repositioning of the implant, the stretch-resistant fibers 16 extend through the embolic coil 12, limiting the separation of the coil windings when the coil 12 is bent and / or stretched. By limiting the separation of the windings, the embolic coil 12 is less likely to entangle when partially implanted, and less likely to stretch or otherwise deform when retracted. This allows the embolic coil 12 to be repositioned more easily than an embolic coil lacking the stretch-resistant fibers 16.

[0038] To reduce the effect of pushback during implantation, the detachment mechanism 18 can be sized to provide an embolization coil implant 10 having a highly flexible proximal section and attached to the embolization coil 12. The embolization coil implant 10 having a highly flexible proximal section reduces the pushback force on the delivery tube 302, thereby reducing the effect of the delivery tube 302 shifting. Additionally or alternatively, the detachment mechanism 18 can be sized to interlock with a delivery tube 302 having a highly flexible distal section, and the highly flexible distal section of the delivery tube can reduce the effect of the delivery tube shifting. When the embolization coil implant 10 having a highly flexible proximal section interlocks with a delivery tube 302 having a highly flexible distal portion, the combination of the flexible distal section of the delivery tube 302 and the flexible proximal section of the implant 10 can further reduce the effect of the delivery tube shifting. Although not shown, the separation mechanism 18 can be tapered to extend further into the lumen 13 of the embolic coil 12, allowing the embolic coil 12 to have additional flexibility surrounding the tapered region. The flat profile of the separation mechanism 18 and the minimum number of fused windings near the proximal end 15 of the coil 18 can also enable high flexibility near the proximal end 15 of the embolic coil 12.

[0039] Figures 3A to 3C are diagrams of the sleeve 29 of the separation mechanism 18. Figure 3A is a perspective view of the first exemplary sleeve 29a and distal opening 24 of the separation mechanism 18. Figure 3B is a plan view of the sleeve opening 46a of the first exemplary sleeve 29a. The first exemplary sleeve 29a includes a tab 48a that extends inward from the periphery of the sleeve opening 46a and converges onto the pull wire opening 49a. Figure 3C is a perspective view of the second exemplary sleeve 29b and distal opening 24 of the separation mechanism 18. The second exemplary sleeve 29b includes a disk 48b within the sleeve opening 46b. The disk 48b has a pull wire opening 49b in the center.

[0040] The tabs 48a and discs 48b of sleeves 29a and 29b may preferably include biocompatible materials that are elastic. The tabs 48a and discs 48b of sleeves 29a and 29b may include one or more bioabsorbable materials. Suitable exemplary materials include silicone, alumina, bioglass, stainless steel, cobalt-chromium alloy, ceramic biomaterials (e.g., hydroxyapatite or zirconia), and polymers (e.g., polyvinyl chloride (PVC), polyethylene (PE), polypropylene (PP), polytetrafluoroethylene (PTFE), polymethyl methacrylate (PMMA), trimethyl carbonate, TMC NAD-lactide, polycaprolactone (PCA), polylactic acid (PLA), polycaprolactone (PCL), polyglycolic acid (PGA), polydioxanone (PDO), polybutyrolactone (PBL), polyvalerolactone (PVL), and poly(lactide-co-glycolide) (PLGA)).

[0041] Figures 4A and 4B show the distal extension 35 of the detachment mechanism 18. Figure 4A shows a first exemplary distal extension 37a having a shallow cavity 35a for receiving the distal end of the pull wire 140. Figure 4B shows a second exemplary distal extension 37b having a deeper cavity 35b for receiving the distal end of the pull wire 140. Preferably, the distal extension 35 has a semiconical shape as shown in Figures 4A and 4B.

[0042] Figure 5 shows the dimensions of the detachment mechanism 18. The proximal portion 32 has a first length L1 measured from the proximal end of the detachment mechanism 18 to the shoulder portion 36a of the detachment mechanism 18. The distal portion 34 has a second length L2 measured from the shoulder portion 36a to the distal end of the detachment mechanism 18. The distal opening 24 of the detachment mechanism 18 has a third length L3. The detachment mechanism 18 may have a first shoulder portion 36a and two shoulder portions 36b opposite the first shoulder portion 36a. The shoulder portions 36a, 36b may be configured to be welded or otherwise attached to the proximal end 15 of the embolus coil 12. The shoulder portions 36a, 36b may be offset by a fourth length L4. The fourth length L4 may depend on the thickness of the winding of the coil 12. Preferably, the fourth length L4 is about half the diameter D1 of the coil windings of the coil 12 (see Figure 1).

[0043] The proximal portion 32 has a first width W1, which is the maximum width of the proximal portion 32, a second width W2, which is the minimum width of the main portion of the proximal portion 32, and a third width W3 of the proximal extension 38. The proximal extension 38 is sized to fit within the lumen of the delivery tube 302, and therefore the third width W3 is smaller than, and preferably approximately equal to, the diameter of the lumen of the delivery tube 302. The distal portion 34 of the detachment mechanism 18 has a fourth width W4, which is smaller than the diameter of the lumen 13 of the embolic coil 12. In some examples, although not shown, the width of the distal portion can taper and narrow distally 54 of the detachment mechanism 18 to improve the flexibility of the embolic coil 12 near the proximal end 15 of the coil. The distal opening 24 of the detachment mechanism 18 may have a fifth width W5.

[0044] The proximal opening 22 may have a non-traumatic surface 23 that the loop wire 400 can press against in order to minimize abrasion of the loop wire 400 by the separation mechanism 18. The distal opening 24 may have a non-traumatic surface 25 that the stretch-resistant fiber 16 can press against in order to minimize abrasion of the stretch-resistant fiber 16 by the separation mechanism 18.

[0045] Figure 6 is a cross-sectional view of the implant 10 with the pull wire 140 attached to the delivery member 300 under compression. The distal extension 35 prevents the pull wire 140 from moving distally into the embolization coil 12, allowing the pull wire 140 to be loaded into the delivery tube 302 under compression.

[0046] Figure 7 shows a system 100 including an implant 10 and a delivery member 300 that navigates the vascular structure through a guide catheter 200. As the system 100 navigates bends A, B, and C, the system 100 tends to extend outward from bends A, B, and C. Similarly, as the delivery tube 302 bends, the pull wire 140 tends to move outward from the delivery tube 302 at bends A, B, and C. As shown in Figure 6, when the system 100 navigates bends A, B, and C without compressing the pull wire 140 and without applying frictional force to the pull wire 140 from the sleeve 29, the distal end of the pull wire 140 can move proximal 52 relative to the loop wire opening 405. In extreme circumstances, the distal end of the pull wire 140 may move proximal past the loop wire opening 405, potentially causing premature release of the implant 10.

[0047] However, as described here, by placing the pull wire 140 under compression as shown in Figure 6, the pull wire 140 has slack to accommodate the movement of the bent portion outward of the delivery tube 302. If the release mechanism 18 includes a sleeve 29 that provides frictional force against the pull wire 140, the sleeve can provide tension to the pull wire 140 to prevent it from moving outward of the delivery tube 302. These mitigation measures can be used alone or in combination to reduce the possibility of premature release of the implant 10.

[0048] Figures 8A to 8D are a series of diagrams showing the detachment of the implant 10 from the delivery member 300. A portion of the delivery tube 302 and a portion of the embolization coil 12 have been cut out for illustrative purposes.

[0049] Figure 8A shows an engagement system including a pull wire 140 and a loop wire 400 in a locking configuration on the release mechanism 18 of the implant 10. The delivery tube 300 includes a compressible portion 306 that can be compressed. The release mechanism 18 is secured to the delivery tube 302 by the loop wire 400 and the pull wire 140, as will be described in more detail in relation to Figure 1.

[0050] Figure 8B illustrates the pull wire 140 being retracted proximally to initiate the release sequence of the implant 10. The pull wire 140 exits the distal extension 35 and / or sleeve 29 of the release mechanism 18 proximally.

[0051] Figure 8C shows the moment when the pull wire 140 exits the opening 405 of the loop wire 400, allowing the distal end 404 of the loop wire 400 to detach and exit the detachment mechanism 18. As shown, there is nothing here holding the implant 10 to the delivery tube 300.

[0052] Figure 8D shows the end of the release sequence. Here, the compressible portion 306 expands / returns to its original shape and "snaps" forward. The distal end 304 of the delivery tube 300 applies an elastic force E to the implant 10, "pushing" it away, ensuring clean separation and delivery of the implant 10. As can be seen in Figure 8D, the delivery tube 302 may include a notch 310 sized and configured to receive the proximal portion 32 of the release mechanism 18 of the implant 10, and similarly, the proximal portion 32 of the release mechanism 18 may be sized to fit into the notch 310 of the delivery tube 302.

[0053] Figures 9A and 9B illustrate an alternative system 100a, including an alternative implant 10a attached to a delivery member 300. The implant 10a includes a tubular braid 12a in place of the embolization coil 12. The detachment mechanism 18a lacks a distal opening 24 and is otherwise configured similarly to the detachment mechanism 18 described and illustrated elsewhere in this specification. The system 100a is configured to deliver the implant 10a as shown in both Figures 9A and 9B. In Figure 9B, portions of the delivery tube 302 and the braid 12a are cut away for illustrative purposes.

[0054] Figure 10 is a flowchart of a method 500 for delivering and releasing an exemplary implant. Method 500 can be applied to any of the exemplary implants 10, 10a, their modifications, and alternative forms disclosed herein, as will be understood by those skilled in the art.

[0055] In step 502, the distal end of the pull wire can be pushed into the distal extension of the implant release mechanism, thereby preventing the distal end of the pull wire from moving distally. The pull wire, release mechanism, and distal extension can be configured similarly to the corresponding components 140, 18, 35, their variations, and their alternative forms disclosed herein, as will be understood by those skilled in the art.

[0056] In step 504, the implant delivery system, including the implant, pull wire, and elongated delivery tube, can be delivered through a vascular structure. The implant delivery system can be configured similarly to the implant delivery systems 100, 100a, their variations, and alternative forms disclosed herein, as will be understood by those skilled in the art. The elongated delivery tube can be configured similarly to the delivery tube 300, its variations, and alternative forms disclosed herein, as will be understood by those skilled in the art. The vascular structure through which the delivery system is delivered may be tortuous. When the delivery system is delivered through a tortuous vascular structure, the longitudinal movement of the distal end of the pull wire can be prevented by a sleeve that provides friction to the pull wire. The sleeve can be configured similarly to the exemplary sleeve 29, its variations, and alternative forms disclosed herein, as will be understood by those skilled in the art. The distal end of the pull wire can be aligned with the distal extension by the sleeve.

[0057] In step 506, the pull wire can be pulled proximally to release the disconnection mechanism from the delivery tube. The pull wire can be pulled proximally through the loop of the loop wire attached to the delivery tube, thereby releasing the loop wire from the opening of the disconnection mechanism and disengaging the disconnection mechanism from the delivery tube.

[0058] The descriptions contained herein are examples of embodiments of the present invention and do not limit the scope of the invention in any way. As described herein, the present invention envisions many variations and modifications of implants, including alternative materials (including bioabsorbable materials), alternative geometric shapes of component parts, alternative positioning of component parts relative to each other, and methods for fabricating and using implants. The modifications will be obvious to those skilled in the art to whom the present invention relates and are intended to be within the scope of the following claims.

[0059] [Implementation Method] (1) A system, A long, slender delivery tube is configured to traverse the vascular structure and extends along the longitudinal axis of the system, An embolization implant including a detachment mechanism, wherein the detachment mechanism includes a distal extension and a proximal opening, A loop wire attached to the delivery tube and extending through the proximal opening of the disconnection mechanism, A pull wire extending through the delivery tube, extending through the opening of the loop wire, and being prevented from moving distally by the distal extension of the disconnection mechanism, A system equipped with these features. (2) The separation mechanism further comprises a sleeve through which the pull wire extends, The system according to Embodiment 1, wherein the sleeve provides frictional force to the pull wire. (3) The sleeve is provided with an elastic material that is positioned around at least a portion of the opening of the sleeve and provides the frictional force to the pull wire, The system according to embodiment 2, wherein the pull wire extends through the opening of the sleeve. (4) The separation mechanism further comprises a sleeve through which the pull wire passes and extends, The system according to Embodiment 1, wherein the sleeve is positioned so as to align the pull wire longitudinally with the distal extension. (5) The separation mechanism further includes a distal portion including the distal extension and a proximal portion including the proximal opening, The system according to Embodiment 1, wherein the proximal portion includes a proximal width greater than the distal width of the distal portion.

[0060] (6) The embolization implant includes an embolization coil, The distal portion of the separation mechanism is positioned within the lumen of the embolization coil. The distal portion includes the distal extension, The proximal portion of the separation mechanism extends proximal to the proximal end of the embolic coil, The system according to Embodiment 1, wherein the proximal portion includes the proximal opening. (7) The distal portion of the separation mechanism further includes a distal opening, The embolization implant further includes stretch-resistant fibers that pass through the distal opening and extend through the lumen of the embolization coil to the distal end of the embolization coil, The system according to Embodiment 6, wherein the stretch-resistant fiber is effective in limiting the separation of the windings of the embolic coil when the embolic coil is under tension. (8) The detachment mechanism includes a first shoulder attached to the proximal end of the embolic coil and a second shoulder attached to the proximal end of the embolic coil, The system according to embodiment 6, wherein the first shoulder portion is offset longitudinally with respect to the second shoulder portion. (9) The system according to Embodiment 1, wherein the embolization implant includes a tubular braid. (10) The elongated delivery tube includes a notch extending from the distal end to the proximal end of the delivery tube, The system according to Embodiment 1, wherein the proximal portion of the separation mechanism is located within the notch.

[0061] (11) The system according to Embodiment 1, wherein the proximal opening includes a non-traumatic surface in contact with the loop wire. (12) The separation mechanism includes a substantially flat first surface and a second surface opposite to the first surface, The system according to Embodiment 1, wherein the distal extension is located on the second surface. (13) The system according to Embodiment 1, wherein the pull wire is compressed longitudinally within the delivery tube. (14) An implant, An embolization tube including a lumen passing through it and defining the longitudinal axis of the implant, A separation mechanism, The distal portion extending within the lumen, The proximal portion of the embolic tube extending proximally from its proximal end, A proximal opening configured to receive a loop wire passing through it, A sleeve including a longitudinal opening configured to receive a pull wire, and a disconnection mechanism, An implant equipped with these features. (15) The implant according to embodiment 14, wherein the detachment mechanism further comprises a distal extension positioned distal to the sleeve and longitudinally aligned with the opening.

[0062] (16) The implant according to Embodiment 14, wherein the sleeve includes an elastic material (48a, 48b) on at least a portion of the periphery of the opening. (17) A method for delivering an implant equipped with a detachment mechanism, the method being: By pushing the distal end of the pull wire into the distal extension of the disconnection mechanism, the distal end of the pull wire is prevented from moving distally, The method involves delivering an implant delivery system via a vascular structure, wherein the implant delivery system comprises an elongated delivery tube, the implant, and the pull wire. The pull wire is pulled proximally, thereby freeing the disconnection mechanism from the delivery tube. Methods that include... (18) Traversing the implant delivery system through a meandering vascular structure, The sleeve, which provides frictional force to the pull wire, prevents the longitudinal movement of the distal end of the pull wire relative to the disconnection mechanism, The method according to embodiment 17, further comprising the above. (19) The method according to embodiment 17, further comprising aligning the distal end of the pull wire with the distal extension of the separation mechanism by a sleeve disposed on the separation mechanism and through which the pull wire extends. (20) The method according to embodiment 17, wherein pulling the pull wire proximally so as to release the disconnection mechanism from the delivery tube further includes pulling the pull wire proximally so as to release the loop wire attached to the delivery tube, so as to cause the loop wire to pass through the disconnection mechanism and out of the opening, thereby disengaging the disconnection mechanism from the delivery tube.

Claims

1. It is a system, A long, slender delivery tube is configured to traverse the vascular structure and extends along the longitudinal axis of the system, An embolization implant including a detachment mechanism, wherein the detachment mechanism includes a distal extension and a proximal opening, A loop wire attached to the delivery tube and extending through the proximal opening of the disconnection mechanism, A pull wire extending through the delivery tube, extending through the opening of the loop wire, and being prevented from moving distally by the distal extension of the disconnection mechanism, Equipped with, A system in which the distal extension has a cavity for receiving the distal end of the pull wire, the cavity has a tapered shape that narrows distally from the proximal end of the cavity, and the distal end of the pull wire is pushed into the cavity distally from the proximal end of the cavity so that the distal end of the pull wire engages with the distal extension.

2. The aforementioned disconnection mechanism further comprises a sleeve through which the pull wire extends, The system according to claim 1, wherein the sleeve provides frictional force to the pull wire.

3. The sleeve comprises an elastic material disposed around at least a portion of the opening of the sleeve and providing the frictional force to the pull wire, The system according to claim 2, wherein the pull wire extends through the opening of the sleeve.

4. The aforementioned disconnection mechanism further comprises a sleeve through which the pull wire passes and extends, The system according to claim 1, wherein the sleeve is positioned so as to align the pull wire longitudinally with the distal extension.

5. The separation mechanism further includes a distal portion including the distal extension and a proximal portion including the proximal opening, The system according to claim 1, wherein the proximal portion includes a proximal width greater than the distal width of the distal portion.

6. The aforementioned embolic implant includes an embolic coil, The distal portion of the separation mechanism is positioned within the lumen of the embolization coil. The distal portion includes the distal extension, The proximal portion of the separation mechanism extends proximal to the proximal end of the embolic coil, The system according to claim 1, wherein the proximal portion includes the proximal opening.

7. The distal portion of the separation mechanism further includes a distal opening, The embolization implant further includes stretch-resistant fibers that pass through the distal opening and extend through the lumen of the embolization coil to the distal end of the embolization coil, The system according to claim 6, wherein the stretch-resistant fiber is effective in limiting the separation of the windings of the embolic coil when the embolic coil is under tension.

8. The separation mechanism includes a first shoulder attached to the proximal end of the embolic coil and a second shoulder attached to the proximal end of the embolic coil. The system according to claim 6, wherein the first shoulder portion is offset longitudinally with respect to the second shoulder portion.

9. The system according to claim 1, wherein the embolization implant includes a tubular braid.

10. The delivery tube includes a notch extending from the distal end to the proximal end of the delivery tube, The system according to claim 1, wherein the proximal portion of the separation mechanism is located within the notch.

11. The system according to claim 1, wherein the proximal opening includes a non-traumatic surface in contact with the loop wire.

12. The separation mechanism includes a substantially flat first surface and a second surface facing the first surface, The system according to claim 1, wherein the distal extension is disposed on the second surface.

13. The system according to claim 1, wherein the pull wire is compressed longitudinally within the delivery tube.

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