Medical device delivery member having a flexible stretch-resistant distal portion - Patents.com

Abstract

To provide a delivery member for delivering and developing an intravascular medical device.SOLUTION: A delivery member 10 is surrounded by a flexible sleeve, and includes a flexible distal part including a wound wire coil which is inhibited from extending in a longitudinal direction by an extension resistant member 600 positioned through a lumen of a coil 212. The delivery member can contain hypotubes 100, 300 to which the extension resistant member and wound wire coil may be fitted and which are positioned on one / the other of both sides (distal direction and proximal direction) from the wound wire coil. The distal hypotube can contain a fitting slot for arranging a loop wire on the distal hypotube for fitting the loop wire.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates generally to an intravascular medical device system that is navigable through the body vasculature of a human subject. More specifically, the present invention relates to a delivery system and delivery members for delivering and deploying an implantable medical device to a target location in the body vasculature, and methods of use thereof. [Background technology]

[0002] The use of catheter delivery systems to position and deploy therapeutic devices (e.g., dilatation balloons, stents, and embolic coils) in the vasculature of the human body has become a standard procedure for treating endovascular diseases. Such devices have proven to be particularly effective when treating areas where traditional surgical procedures are not possible or pose a great risk to the patient, such as treating aneurysms in cerebral blood vessels. Due to the delicate tissues, such as brain tissue, surrounding cerebral blood vessels, performing surgical procedures to treat defects in cerebral blood vessels can be very difficult and often dangerous. Advances in catheter-based implant delivery systems have provided alternative treatments in such cases. Advantages of catheter delivery systems include providing a method for treating blood vessels with an approach that has been shown to reduce the risk of trauma to the surrounding tissue, and further enabling the treatment of blood vessels that were previously considered inoperable.

[0003] Generally, these procedures involve inserting a delivery catheter into the patient's vasculature and guiding it through the vasculature to a predetermined delivery site. A vaso-occlusive device, such as an embolic coil, can be attached to an implant engagement / deployment system (equivalently referred to herein as an "engagement system" or "deployment system") at the distal end of a delivery member (e.g., a microcatheter), which pushes the coil through the delivery catheter and out the distal end of the delivery catheter to the delivery site. Exemplary delivery members and engagement / deployment systems are described in U.S. Patent Application Nos. 15 / 850,993, 15 / 964,857, and 16 / 502,767, each of which is incorporated herein by reference.

[0004] Some of the difficulties associated with properly performing such treatment procedures include ensuring that the delivery member and engagement system remain in a stable position throughout the treatment. For example, in some aneurysm treatment applications, as the aneurysm becomes increasingly filled with embolic material, the delivery member may tend to move due to increasing pushback from the embedded embolic material. If the delivery member moves during treatment, the physician may not be able to precisely control the placement of the embolic material and may choose to stop filling the aneurysm. In such instances, the aneurysm may not be fully filled, which may result in recanalization. Additionally, excessive movement or stretching of the delivery member and / or the associated engagement system may result in premature detachment of the embolic coil. Summary of the Invention [Problem to be solved by the invention]

[0005] Thus, a need exists for improved methods, devices, and systems for providing implant delivery members and implant engagement systems with improved stability. [Means for solving the problem]

[0006] It is an object of the present invention to provide a system, apparatus, and method that meets the above-mentioned needs.In general, it is an object of the present invention to provide a delivery member for delivering and deploying an implantable medical device having a flexible distal portion.

[0007] The stiffness of the distal portion of the delivery member can cause a microcatheter used to deliver embolic material to be pulled back from the aneurysm as the distal end of the delivery member is advanced through tortuous distal anatomy. If the microcatheter is pulled back while advancing embolic material, the microcatheter can be allowed to exit the aneurysm, potentially allowing the physician to lose control of the embolic coil, and may not be able to precisely control the placement of the embolic material and complete the treatment.

[0008] Flexibility can be provided by incorporating a length of coil wound along the distal portion of the delivery member. The wound coil can be protected by a flexible polymer sleeve positioned around the outside of the coil. The wound coil can prevent stretching of stretch-resistant tubing attached to the hypotube at either end of the wound coil.

[0009] An exemplary delivery member for delivering an implantable medical device to a target location in a body vessel can include a proximal hypotube, a support coil section, a distal hypotube, and an engagement system. The support coil section can be attached to a distal end of the proximal hypotube. The distal hypotube, the support coil section, and the proximal hypotube can form a continuous tubular structure having a lumen therethrough. The distal hypotube can have a distal end shaped to receive the implantable medical device. The distal hypotube can include a first attachment slot extending from the lumen to an outer surface of the distal hypotube. The distal hypotube can include a second attachment slot extending from the lumen to an outer surface of the distal hypotube. The engagement system can be movable to engage and deploy the implantable medical device. The engagement system can include a loop wire and a pull wire. The loop wire can extend through an opening in the implantable medical device to engage the engagement system with the implantable medical device. The loop wire can have a first end and a second end. The first end can extend at least partially through the first attachment slot and the second end can extend at least partially through the second attachment slot. The pull wire can extend through the lumen to engage the loop wire to engage the engagement system with the implantable medical device. The pull wire can be moved to retract proximally to release the loop wire and deploy the implantable medical device.

[0010] The first mounting slot can have a distal end and a proximal end. The proximal end can have a first diameter and the distal end can have a second diameter. The first diameter of the first mounting slot can be larger than the second diameter of the first mounting slot. Similarly, the second mounting slot can have a distal end and a proximal end. The proximal end can have a first diameter and the distal end can have a second diameter. The first diameter of the second mounting slot can be larger than the second diameter of the second mounting slot.

[0011] The delivery member may further include a first attachment connecting a first end of the loop wire to the first mounting slot and a second attachment connecting a second end of the loop wire to the second mounting slot.

[0012] The loop wire may be a metallic material and the first attachment and / or the second attachment may be a weld.

[0013] The first attachment and / or the second attachment may include an epoxy.

[0014] The first attachment can be a first knot in the loop wire having a knot diameter approximately equal to the first diameter of the first mounting slot, and the second attachment can be a second knot in the loop wire having a diameter approximately equal to the first diameter of the second mounting slot.

[0015] The loop wire may be a polymeric material.

[0016] The distal hypotube can have a helical cut along its longitudinal axis through the lumen.

[0017] The first mounting slot can be disposed on the distal hypotube opposite the second mounting slot along a diameter line passing through the longitudinal axis, and the first mounting slot can be disposed proximal to the second mounting slot by a distance equal to half the pitch of the helical cut.

[0018] The first mounting slot can be located at a first location equidistant from two adjacent gaps in the helical cut. The second mounting slot can be located at a second location equidistant from two adjacent gaps in the helical cut.

[0019] The first mounting slot and the second mounting slot may be perpendicular to the longitudinal axis.

[0020] An exemplary distal hypotube for a delivery member can have a distal end shaped to receive an implantable medical device. The distal hypotube can have a lumen extending therethrough. The distal hypotube can include a first attachment slot extending from the lumen to an outer surface of the distal hypotube. The distal hypotube can include a second attachment slot extending from the lumen to the outer surface. The distal hypotube can have a loop wire. The loop wire can be attached at a first end to the first attachment slot and at a second end to the second attachment slot. The distal hypotube can have a helical cut in the outer surface. The helical cut can be cut along a longitudinal axis through the lumen.

[0021] The first mounting slot can have a distal end and a proximal end. The proximal end of the first mounting slot can have a larger diameter than the distal end of the first mounting slot. The second mounting slot can have a distal end and a proximal end. The proximal end of the second mounting slot can have a larger diameter than the distal end of the second mounting slot. A loop wire can be attached to the first mounting slot by a first attachment. A loop wire can be attached to the second mounting slot by a second attachment.

[0022] The loop wire may be a metallic material and the first attachment and / or the second attachment may be a weld.

[0023] The first attachment and / or the second attachment may include an epoxy.

[0024] The first attachment can be a first knot in the loop wire having a knot diameter approximately equal to the first diameter of the first mounting slot, and the second attachment can be a second knot in the loop wire having a diameter approximately equal to the first diameter of the second mounting slot.

[0025] The first mounting slot can be disposed on the distal hypotube opposite the second mounting slot along a diameter line passing through the longitudinal axis, and the first mounting slot can be disposed proximal to the second mounting slot by a distance equal to half the pitch of the helical cut.

[0026] An exemplary method for mounting an implantable medical device on a delivery member includes providing a delivery member. The delivery member can include a flexible distal hypotube. The method can include threading a first end of a loop wire through a proximal end of a first mounting slot of the flexible distal hypotube. The method can include pulling the first end of the loop wire from the proximal end of the first mounting slot toward a distal end of the first mounting slot having a smaller diameter than the proximal end. The method can include mounting the loop wire in the first mounting slot. The method can include threading a second end of the loop wire through a proximal end of a second mounting slot of the flexible distal hypotube. The method can include pulling the second end of the loop wire from the proximal end of the second mounting slot toward a distal end of the second mounting slot having a smaller diameter than the proximal end. The method can include mounting the loop wire in the second mounting slot.

[0027] Attaching the loop wire to the first mounting slot may include welding the loop wire into the first mounting slot.

[0028] The method can include tying a first knot on a first end of the loop wire prior to pulling the first end of the loop wire from a proximal end of the first mounting slot toward a distal end of the first mounting slot, and tying a second knot on a second end of the loop wire prior to pulling the second end of the loop wire from a proximal end of the second mounting slot toward a distal end of the second mounting slot. [Brief description of the drawings]

[0029] The above and further aspects of the present invention will be further discussed with reference to the following description 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 on illustrating the principles of the invention. The figures depict one or more implementations of an apparatus of the present invention, by way of example only and not by way of limitation. [Figure 1] 1 is a cross-sectional view of a delivery member according to an embodiment of the present invention. [Figure 2A] FIG. 2A is a cross-sectional view of a flexible sleeve according to an embodiment of the present invention. [Figure 2B] (B) A cross-sectional view of a stretch-resistant tube according to an embodiment of the present invention. [Figure 2C] (C) Cross-sectional view of a wire coil attached to a distal hypotube and a proximal hypotube according to an embodiment of the present invention. [Figure 2D] 13D and 13E are diagrams of a distal hypotube having first and second attachment slots according to an embodiment of the invention. [Figure 2E] 13D and 13E are diagrams of a distal hypotube having first and second attachment slots according to an embodiment of the invention. [Figure 2F] 11(F)-(H) are diagrams of a distal hypotube having first and second attachment slots according to an embodiment of the invention. [Figure 2G] 11(F)-(H) are diagrams of a distal hypotube having first and second attachment slots according to an embodiment of the invention. [Figure 2H]11(F)-(H) are diagrams of a distal hypotube having first and second attachment slots according to an embodiment of the invention. [Figure 3A] 1A-D are diagrams of an engagement system outlining a sequence for deploying an implant according to an embodiment of the present invention. [Figure 3B] 1A-D are diagrams of an engagement system outlining a sequence for deploying an implant according to an embodiment of the present invention. [Figure 3C] 1A-D are diagrams of an engagement system outlining a sequence for deploying an implant according to an embodiment of the present invention. [Figure 3D] 1A-D are diagrams of an engagement system outlining a sequence for deploying an implant according to an embodiment of the present invention. [Figure 4] FIG. 2 is a flow diagram illustrating a method for designing and / or constructing a delivery member, according to an embodiment of the present invention. [Diagram 5] 1 is a flow diagram illustrating a method for using a delivery system including an exemplary delivery member, according to an aspect of the present invention. [Figure 6] FIG. 1 is a flow diagram illustrating a method for attaching an implantable medical device to a delivery member. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0030] During an intravascular procedure, such as an aneurysm occlusion treatment, a lack of flexibility in the distal portion of the delivery member of the treatment device may cause the delivery member to retract or otherwise move out of position from the treatment site while an implant or other medical treatment device is being placed at the aneurysm or other treatment site. Thus, a delivery member and engagement system having a more flexible distal portion may provide a stable system for delivering medical devices to neurovascular anatomy, in addition to other applications that face similar challenges. However, flexible structures may tend to deform, stretch, or expand when navigating tortuous anatomy. Deformation of the delivery member may inhibit the ability of the delivery member to navigate to the treatment site and / or to effectively deploy the medical device. Stretching of the delivery member may result in premature deployment of the medical device.

[0031] It is an object of the present invention to provide a delivery member having a highly flexible distal portion that is stretch resistant and structurally stable throughout the delivery and deployment of a medical therapeutic device. For ease of explanation, the medical therapeutic device will be generally referred to herein as an "implant", however, as will be recognized and understood by those skilled in the art, aspects of the present invention may be applied to the delivery and deployment of non-implanted medical therapeutic devices.

[0032] According to the present invention, in some examples, the highly flexible distal portion of the delivery member can include a coiled wire, an outer sleeve, and an inner stretch-resistant member. The coiled wire can be formed of a substantially linear wire wound into a coil shape and / or a hypotube laser cut in a helical pattern. If the coiled wire is formed from a laser cut hypotube, the helix may be free of interfering cuts connecting the windings within the coil to provide a more flexible coil. The outer sleeve can prevent the coiled wire from deforming radially and / or provide a smooth surface against which the vessel wall can slide during delivery of the implant. The stretch-resistant member can prevent the coiled wire from stretching during delivery of the implant. Thus, the combination of the coiled wire, outer sleeve, and stretch-resistant member can provide a distal portion of the delivery member with greater flexibility and greater stability than at least some known delivery members.

[0033] Referring to the drawings, as shown in FIG. 1, an exemplary delivery member 10 can include a proximal tube 100, a coil section 200, a distal tube 300, a sleeve 500 surrounding the coil section, and a stretch-resistant member 600 within the lumen of the coil section 200. In this disclosure, the terms proximal tube and proximal hypotube can be used interchangeably. Similarly, the terms distal tube and distal hypotube can be used interchangeably. The proximal tube 100 can extend the majority of the length of the delivery member 10 with the coil section 200 and the distal tube 300, forming a length sufficient to absorb most of the pushback that may occur during placement of the implant at the treatment site. In some examples, the length can be about 30 cm to about 50 cm, or more specifically about 40 cm. The proximal tube 100 can have a distal end 104 connected to a proximal end 202 of the coil section 200, which can have a distal end 204 connected to a proximal end 302 of the distal tube 300. As described in more detail herein, the distal tube 300 can include a compressible portion 306. The compressible portion 306 can be formed from a helical break 307 in the distal tube 300, a wound wire, a helical ribbon, or other configuration that allows for axial adjustment in accordance with the present invention. A loop wire 400 can be disposed within the lumen 308 of the distal tube 300 that can secure an implant or other medical procedure device to the delivery member 10. The compressible portion 306 of the distal tube 300 can have attachment slots (e.g., first attachment slot 310 and second attachment slot 316) that allow the loop wire 400 to be threaded through the distal tube 300 from the lumen 308 to the outer surface 309 of the distal hypotube.

[0034] Figure 2A is a cross-sectional view of sleeve 500. Figure 2B is a cross-sectional view of stretch resistant member 600. Figure 2C is a cross-sectional view of the assembled proximal tube 100, coil section 200 and distal tube 300.

[0035] The coil section 200 may be formed separately from the proximal hypotube 100 and / or the distal hypotube 300. The separately formed coil section 200 may be attached with welds 712, 714, or other suitable attachments to the proximal tube 100 and / or the distal tube 300. Additionally or alternatively, at least a portion of the coiled section may be formed from a helical laser cut section of hypotube. The separately formed coil section 200 may be made more flexible compared to a helical cut tube by selecting a wire having a particular cross section (e.g., circular) with a particular diameter D, or by selecting a wire with material properties that increase flexibility. Conversely, the laser cut section may be more easily fabricated by cutting a single hypotube to form the proximal tube 100, coil section 200, and distal hypotube 300, reducing or eliminating the welds 712, 714, or other attachments. In either case, the wire of coil 200 can have a diameter D measured within a range inclusive of about 0.8 mils and 5 mils (about 20 nm to about 130 nm).

[0036] The coiled section may be formed primarily from a non-radiopaque material such as steel and may include a radiopaque section 216 made from a radiopaque material such as platinum and / or tungsten. The radiopaque section 216 may be positioned between the proximal non-radiopaque section of the coil 212 and the distal non-radiopaque section of the coil 214. The radiopaque section 216 may be positioned a predetermined distance from the distal end 304 of the delivery member 10 to allow a physician to easily visualize the placement of the distal portion of the delivery member during a treatment procedure. The proximal section 212, the radiopaque section 216, and the distal section 214 may be concentrically welded.

[0037] The coil section 200 may be surrounded by a flexible sleeve or fused jacket 500, collectively referred to herein as a "sleeve." The sleeve 500 may prevent the coil 200 from radially expanding and / or engaging the vessel wall during navigation. The sleeve 500 may include a polymer. The polymer may include additives to increase the lubricity of the sleeve 500, allowing the sleeve to slide easily through the vessels of the body. As shown in FIG. 2A, the sleeve 500 may have a wall thickness T measured within a range such as about 0.5 mils and about 2 mils (about 0.01 mm to about 0.05 mm). The sleeve 500 may be further coated with a hydrophilic coating to further minimize friction during intravascular navigation. The sleeve 500 may be fused or bonded to the coil 200, the proximal hypotube 100, and / or the distal hypotube 300.

[0038] The stretch resistant member 600 can be positioned to prevent the coil 200 from stretching during intravascular navigation. The stretch resistant member 600 can include a tube sized to fit inside the lumen 208 of the coil 200. The stretch resistant tube 600 can also be sized to extend through the entire length of the coil 200 and can be sized to extend into the lumen 308 of the distal tube 300 as well as the lumen 108 of the proximal tube 100. The stretch resistant member 600 can be attached to the proximal tube 100 and the distal tube 300 with adhesive joints 702, 704 or other suitable attachments. The stretch resistant member 600 can remain unattached to the coil sections 200 such that the stretch resistant member 600 and the coil sections 200 can move to some degree independent of one another.

[0039] The delivery member 10 may include a mechanical engagement system for engaging the medical device 12 during delivery to the treatment site, and the delivery member 10 may be mechanically actuated to deploy the medical device 12. A mechanically actuated engagement system may include one or more inner elongate members or pull wires extending through the delivery member that may be manipulated at a proximal end by a physician to deploy the medical treatment device. Such wires or inner elongate members are collectively referred to herein as "pull wires." When referring to an engagement system herein, the engagement system may include a combination of a loop wire 400 and a pull wire 140.

[0040] 2D-2H show an exemplary distal hypotube 300 that can be used to secure a loop wire 400. The loop wire 400 can be positioned to secure an implant or other medical treatment device to a delivery member 10 and can be moved to release the medical device 12 from the implant or other medical treatment device. This conventional approach is described in more detail below with reference to FIGS. 3A-3D. In summary, the loop wire 400 can be extended over the locking portion 18 of the medical device 12. The pull wire 140 can then be slid through an opening 405 in the distal end 404 of the loop wire 400. This can hold the medical device 12 in place until the pull wire 140 can be retracted to release the medical device 12.

[0041] 2D is a side view of the distal hypotube 300 having a first attachment slot 310 and a second attachment slot 316 (the second attachment slot 316 is behind the view). The attachment slots 310, 316 may be openings in the outer surface 309 of the distal hypotube 300 that extend from the lumen 308 to the outer surface 309. The attachment slots 310, 316 may facilitate attachment of the loop wire 400 to the distal hypotube 300. The attachment slots 310, 316 may be laser cut, for example, into the outer surface 309 of the distal hypotube 300.

[0042] The first attachment slot 310 can have a distal end 312 and a proximal end 314. As can be seen, the diameter 313 at the distal end 312 of the first attachment slot 310 can be smaller than the diameter 315 at the proximal end 314. This tapered design can facilitate attachment of the loop wire 400 to the distal hypotube 300. For example, the loop wire 400 can be routed more easily if the diameter of the proximal end 314 is larger. Once the loop wire 400 is threaded through the larger proximal diameter 315, it can be pulled towards the distal end (312) of the first attachment slot (310). In some embodiments, the transition between the proximal end 314 and the distal end 312 can be slightly tapered, which can allow the loop wire 400 to be wedged within the first attachment slot as it is pulled towards the distal end 312. The second mounting slot 316 can be similar in all respects to the first mounting slot 310. For example, the second mounting slot 316 can have a distal end 322 and a proximal end 324, and the diameter 323 of the distal end 322 can be smaller than the diameter 325 of the proximal end 324 of the second mounting slot 316.

[0043] The loop wire 400 can be routed through the attachment slots 310, 316 and attached to the distal hypotube 300 by the attachments 409, 409 as it is pulled toward the distal end 312, 322. FIG. 2E shows an exemplary first attachment 408 (the second attachment 409 is behind this view). Using the first attachment slot 310 as an example (the second attachment slot 316 can be similar), the loop wire 400 can be pulled toward the distal end 312 and positioned within the first attachment slot 310 at a desired location within the length of the first attachment slot 310. The loop wire 400 can then be attached to the first attachment slot 310 with the first attachment 408. The first attachment 408 and / or the second attachment 409 can be positioned at the distal end of their corresponding attachment slots 310, 316. However, the first attachment 408 and / or the second attachment 409 do not have to be located at the distal most end of the slot, but rather the first attachment 408 and / or the second attachment 409 can be located in an intermediate portion (i.e., more proximal) of the slot, as shown in FIG. 2E.

[0044] The first attachment 408 can be a weld that holds the loop wire 400 in the first attachment slot 310. In some examples, the loop wire 400 can include a metallic material such as stainless steel, cobalt chrome alloy, titanium, nickel titanium alloy (nitinol), etc. Similarly, the distal hypotube can include a metallic material such as stainless steel, cobalt chrome alloy, titanium, nitinol, etc. This allows the first attachment 408 to be a metallic weld that attaches the loop wire 400 to the first attachment slot 310. In some examples, the loop wire 400 can include a polymeric material such as nylon, polypropylene, silk, polyester, etc. The loop wire can include braided or monofilament wire. The first attachment 408 can also be a thermoplastic weld of the first attachment slot 310.

[0045] Additionally or alternatively, the first attachment 408 may be an epoxy that holds the end of the loop wire 400 to the first mounting slot 408. As described above, the second mounting slot 316 may include a second attachment 409 for attaching the loop wire 400 to the second mounting slot 316. The second attachment 409 may be similar to the first attachment 408.

[0046] In some examples, the first attachment 408 can be a knot on the loop wire 400. As discussed above, the first attachment slot 310 can have a proximal end 314 with a larger diameter than the distal end 312. The loop wire 400 can be pulled through the first attachment slot 310, tied into a knot, and then pulled toward the distal end 312. The knot can be larger than the distal diameter 313 such that the loop wire 400 cannot be pulled back through the first attachment slot 310 after the loop wire 400 is tied into the knot. In other examples, the loop wire 400 can first be tied into a knot and then the knot can be fed through the proximal end 314 of the first attachment slot 310, and then the loop wire 400 can be pulled toward the distal end 312. In these examples, the diameter of the knot can be approximately equal to the first diameter 315 of the first attachment slot 310. This allows the loop wire 400 to be routed through the proximal end 314, but prevents the loop wire 400 from being pulled through the distal end 312 of the first attachment slot 310. The second attachment 409 may similarly be a knot on the opposite end of the loop wire 400.

[0047] 2F is a side view of an exemplary distal hypotube 300. The first attachment slot 310 is at the front of this view and the second attachment slot 316 is at the back. As discussed above, the distal hypotube 300 can have a flexible and / or compressible portion 306. The compressible portion 306 can be formed from a helical cut 307 in the distal hypotube 300, a wound wire, a helical ribbon, or other configuration that allows for axial adjustment in accordance with the present invention. In some examples, the placement of the first attachment slot 310 and / or the second attachment slot 316 can be selected based on the pitch of the helical cut 307. To increase the flexibility of the distal hypotube 300, the first attachment slot 310 can be offset from the second attachment slot 316 by the ratio of the pitch of the helical cut 307, as shown, for example, by the slot offset 320. As shown in the figures, in this example slot offset 320, the first mounting slot 310 can be located opposite the second mounting slot 316 and the first mounting slot 310 can be offset proximally of the second mounting slot 316 by a distance approximately equal to half the pitch 318 of the helical cut 307. However, the first mounting slot 310 does not have to be located opposite the second mounting slot 316. The first mounting slot 310 can be located at a first location equidistant from two adjacent cuts in the helical cut 307 and the second mounting slot 316 can be located at a second location equidistant from two adjacent cuts in the helical cut 307. This is true for any location on the distal hypotube 300, regardless of whether the mounting slots 310, 316 are opposite each other on the outer surface 309.

[0048] 2G is a perspective view of the distal hypotube 300 illustrating an exemplary offset between the first and second mounting slots 310, 316. Offsetting the first and second mounting slots 310, 316 relative to the pitch of the helical cut 307 can increase flexibility of the distal hypotube 300 by not hindering bending of the hypotube about the helical cut 307.

[0049] 2H is a side cross-sectional view of an exemplary hypotube 300. In some examples, the first and second attachment slots 310, 316 can be formed in the distal hypotube 300 (e.g., by laser cutting, drilling, etc.) perpendicular to a longitudinal plane 326b through the lumen 308 of the distal hypotube 300. The longitudinal plane 326b is a three-dimensional view of the longitudinal axis 326b through the lumen 308. The perpendicular cuts can help facilitate attachment of the loop wire 400 to the first and second attachment slots 310, 316. For example, as the loop wire 400 is routed through the first and second attachment slots 310, 316, the perpendicular cuts can help ensure uniform surface contact between the loop wire 400 and the outer walls of the attachment slots 310, 316.

[0050] 2H also clearly illustrates an example slot offset 320 between the first and second mounting slots 310, 316. As discussed above, the first mounting slot 310 can be located on the distal hypotube 300 opposite the second mounting slot 316 along a diametric line passing through the longitudinal axis 326a. The first and second mounting slots 310, 316 can be offset based on the pitch of the helical cut 307.

[0051] 3A-3D show a delivery member 10 including a mechanical engagement system including a pull wire 140 and a loop wire 400 that can be positioned to secure an implant or other medical treatment device to the delivery member 10 and can be moved to release the medical treatment device from the delivery member 10. The loop wire 400 can be secured to the distal tube 300 using a first attachment 408 and a second attachment 409. The stretch resistant member 600 can be sized to allow the pull wire 140 to pass through the lumens 108, 208, 308 of the proximal tube 100, the coil section 200, and the distal tube 300. For example, the stretch resistant member 600 can be tubular with a lumen therethrough, and the pull wire 140 can extend through the lumen of the tubular stretch resistant member 600. During manufacture of the stretch resistant member 600, the stretch resistant member 600 can be extruded over the pull wire 140.

[0052] The combination of the coil 200, sleeve 500, and stretch resistant member 600 can provide a highly flexible distal portion of the delivery member 10 suitable for navigating tortuous anatomy, including neurovascular structures. The stretch resistant member 600 can support the coil 200 and prevent it from stretching significantly during vascular navigation, thereby reducing tension on the pullwire 140 extending therethrough and reducing the likelihood of premature deployment of an attached medical therapeutic device.

[0053] The proximal tube 100 may include a flexible section 106 from which material has been removed to increase the flexibility of the flexible section 106. The flexible section 106 may be cut in a helical pattern. The helical pattern of the flexible section 106 may lack interfering cuts connecting the windings within the helix. The stretch-resistant member 600 may extend through the flexible section 106 and be attached to the proximal tube 100 in a proximal direction from the flexible section 106. In this way, the stretch-resistant member 600 may prevent the proximal tube 100 and the flexible section 106 of the coil section 200 from stretching. The sleeve 500 may cover at least a portion of the flexible section 106 to prevent deformation of the flexible section during intravascular navigation and / or reduce friction with the vascular structures and the flexible section 106. In some examples, the sleeve 500 can cover approximately 10 cm of the proximal tube 100 approaching and / or including the distal end 104 of the proximal tube 100 .

[0054] The distal tube 300 can have a compressible portion 306. The compressible portion 306 can be axially adjustable between an elongated state and a compressed state. The distal hypotube 300 can also be flexible such that the distal hypotube 300 provides a stable system for delivery of a medical device within the neurovascular anatomy. The distal hypotube 300 can have a helical cut 307 formed, for example, by a laser cutting operation to create a compressible and / or flexible structure. Additionally or alternatively, the compressible portion 306 can be formed of a wire wound, a helical ribbon, or other configuration that allows for axial adjustment in accordance with the present invention. Preferably, the compressible portion 306 is in an elongated state at rest and will automatically or elastically return from the compressed state to the elongated state unless otherwise restrained.

[0055] 3A-3D illustrate the removal of a medical device 12 using a mechanical engagement / deployment system. FIG. 3A shows the engagement system 140, 400 engaged to the locking portion 18 of the medical device 12. The compressible portion 306 of the distal tube 300 can be compressed and the opening 405 of the loop wire 400 at the distal end 404 of the loop wire 400 can be positioned through the locking portion 18. Once the pull wire 140 is threaded through the opening 405, the medical device 12 is secured. FIG. 3B shows the pull wire 140 being pulled proximally to initiate the release sequence of the medical device 12. FIG. 3C illustrates the moment the pull wire 140 exits the opening 405 and is unwound from the loop wire 400. The distal end 404 of the loop wire 400 moves away and out of the locking portion 18. As can be seen, at this point there is nothing holding the medical device 12 to the delivery member 10 (e.g., the distal hypotube 300). Figure 3D shows the end of the release sequence. The compressible portion 306 now expands / returns to its original shape and "springs" forward. An elastic force E is applied by the distal end 304 of the distal tube 300 to the medical device 12, "pushing" it out and ensuring complete detachment and delivery of the medical device 12.

[0056] The above description of the drawings shows generally hollow or tubular structures 100, 200, 300, 500, 600 according to the present invention. As used herein, the terms "tubular" and "tube" are intended to be broadly interpreted and are not limited to right cylindrical structures, structures that are strictly circular in cross section, or structures that are uniform in cross section over their length. For example, tubular structures or 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.

[0057] FIG. 4 is a flow chart including method steps for constructing or designing a delivery member, such as the exemplary delivery members described herein. Referring to the method 800 outlined in FIG. 4, in step 810, a first hypotube, a second hypotube, a flexible sleeve, a wire coil, and a stretch-resistant member can be selected. The first hypotube can be the proximal hypotube 100 as described herein or as otherwise known to one of ordinary skill in the art. The second hypotube can be the distal hypotube 300 as described herein or as otherwise known to one of ordinary skill in the art. The flexible sleeve can be the sleeve or fused jacket 500 as described herein or as otherwise known to one of ordinary skill in the art. The wire coil can include a support coil, a coil section 200 as described herein, or as otherwise known to one of ordinary skill in the art. The stretch-resistant member can be a stretch-resistant member 600 as described herein or as otherwise known to one of ordinary skill in the art.

[0058] In step 820, a stretch resistant member can be positioned in the lumen of the wire coil. In step 820, the positioned stretch resistant member can be substantially tubular. In step 830, the first hypotube, the wire coil, and the second hypotube can be attached to one another. In step 840, the stretch resistant member is attached to the first hypotube and the second hypotube. The first hypotube, the wire coil, and the second hypotube can be attached as shown and described herein or by other means as would be understood by one of ordinary skill in the art. Steps 820, 830, and 840 do not have to be performed in that order and can be performed simultaneously. For example, a stretch-resistant member may be attached to one of the first and second hypotubes as shown in step 840, then the hypotube to which the stretch-resistant member is attached can be attached to the wire coil as shown in step 830, then the stretch-resistant member can be positioned through the wire coil as shown in step 820, then the other of the hypotubes can be attached to the wire coil as shown in step 830, and then the stretch-resistant member can be attached to the other hypotube as shown in step 840.

[0059] At step 850, the wire coil may be covered with a flexible sleeve. The flexible sleeve may cover some or all of the outer surface of the wire coil. Step 850 may also include fusing the flexible sleeve to the wire coil and / or otherwise attaching the flexible sleeve to the delivery member. If the second hypotube has a flexible section, at step 850, the flexible sleeve may also be positioned to cover at least a portion of the flexible section.

[0060] At step 860, the implant can be removably attached to the distal end of the first hypotube. At step 860, the implant can be attached by positioning a loop wire within the first hypotube and a pull wire can be extended through the first hypotube, the coil wire, and the second hypotube and positioned by securing the implant with the loop wire and the pull wire. The pull wire can extend from a proximal end of the second hypotube. If the first hypotube has a compressible portion, at step 860, the compressible portion can be compressed and the implant can be attached to the delivery member while the compressible portion is compressed.

[0061] 5 is a flow chart including method steps for administering an intravascular treatment using a system including a delivery member, such as the examples of delivery members described herein. Referring to method 900 outlined in FIG. 5, in step 910, a system can be selected having a distal hypotube, a proximal hypotube, a coil section coaxially positioned between the hypotubes, a flexible sleeve covering the coil section, a stretch resistant member positioned within the coil section, and a medical treatment device attached to or near the distal hypotube. The system can be suitable for intravascular treatment as described and illustrated herein or as otherwise known to one of skill in the art.

[0062] At step 920, the system can be moved through a catheter to a treatment site, such as the site of an aneurysm or other abnormality in a blood vessel. At step 930, the system can be bent as it is moved through the catheter. At step 940, the coil section of the system can be prevented from deforming by a flexible sleeve and a stretch resistant member, where the flexible sleeve can prevent the coil section coil from deforming radially while the stretch resistant member can prevent the coil from extending longitudinally.

[0063] At step 950, the medical therapeutic device may be deployed. If the medical therapeutic device is an implant, at step 950, the implant may be removed. At step 960, the distal tube may be extended to push the medical therapeutic device out of the distal tube. If the medical therapeutic device is an implant that was removed at step 950, at step 960, the detached implant may be expelled from the distal tube in response to expansion of the distal tube.

[0064] FIG. 6 is a flow diagram including method steps for attaching an implantable medical device to a delivery member. Referring to method 1000 outlined in FIG. 6, in step 1010, a delivery member can be provided. The delivery member can include a flexible distal hypotube as described herein. In step 1020, a first end of a loop wire can be threaded through a proximal end of a first attachment slot of the distal hypotube. In step 1030, the first end of the loop wire can be pulled from the proximal end of the first attachment slot in a direction toward the distal end. As noted above, the distal end of the first attachment slot can have a smaller diameter than the proximal end.

[0065] At step 1040, the loop wire can be attached to the first mounting slot. This attachment can be done in a variety of ways as described herein above. The loop wire can be welded to the first mounting slot. In another example, the loop wire can be secured to the first mounting slot via epoxy. In another example, the loop wire can have a knot tied to a first end of the loop wire. The knot can be tied before pulling the first end of the loop wire through the proximal end of the first mounting slot. In this case, the knot can be approximately the same size as the diameter of the proximal end of the first mounting slot. This allows the knot to be fed through the proximal end but prevents the knot from being pulled back through the distal end. The knot can also be tied after the first end of the loop wire is pulled through the proximal end of the first mounting slot. The knot can be larger than one or both of the proximal and distal ends of the first mounting slot such that the loop wire cannot be pulled back through the first mounting slot. The first end of the loop wire can be attached to the distal end of the first attachment slot, or the first end of the loop wire can be attached to any other location within the first attachment slot that is narrower than the proximal end (see, e.g., FIG. 2E). In steps 1050-1070, the method steps outlined above in steps 1020-1040 can be repeated for the second attachment slot. For example, the second end of the loop wire can be placed in the second attachment slot similar to the process described above with respect to the first end of the loop wire and the first attachment slot.

[0066] The descriptions contained herein are examples of embodiments of the invention and are not intended to limit the scope of the invention in any way. As described herein, the invention contemplates many variations and modifications of the delivery system, delivery members, and engagement systems, including alternative component configurations, alternative materials, alternative medical treatment devices, alternative means for deploying the medical treatment devices, alternative geometric shapes of the individual components, alternative means for attaching the components, etc. These modifications will be apparent to those skilled in the art to which the invention pertains and are intended to be within the scope of the following claims.

[0067] [Embodiment] (1) A delivery member for delivering an implantable medical device to a target location in a blood vessel of a body, the delivery member comprising: A proximal hypotube; a supporting coil section attached to a distal end of the proximal hypotube; A distal hypotube, a distal end configured to receive the implantable medical device; a first attachment slot extending from a lumen of the distal hypotube to an outer surface of the distal hypotube; a distal hypotube having a second attachment slot extending from the lumen to the outer surface; an engagement system movable to engage and deploy the implantable medical device engaged to the distal end of the distal hypotube, the engagement system comprising: a loop wire that extends through an opening in the implanted medical device to engage the engagement system with the implanted medical device, a first end of the loop wire extending at least partially through the first mounting slot and a second end of the loop wire extending at least partially through the second mounting slot; a pull wire extending through the lumen and engaging the loop wire to engage the engagement system with the implanted medical device, the pull wire being movable by retracting proximally to release the loop wire and deploy the implanted medical device. (2) the first mounting slot has a distal end and a proximal end, the proximal end having a first diameter and the distal end having a second diameter, the first diameter of the first mounting slot being greater than the second diameter of the first mounting slot; A delivery member as described in embodiment 1, wherein the second mounting slot has a distal end and a proximal end, the proximal end having a first diameter and the distal end having a second diameter, and the first diameter of the second mounting slot is larger than the second diameter of the second mounting slot. (3) a first attachment connecting the first end of the loop wire to the first mounting slot; A delivery member as described in embodiment 2, further comprising a second attachment connecting the second end of the loop wire to the second mounting slot. (4) the loop wire comprises a metal material; the first attachment is a weld; 4. The delivery member of embodiment 3, wherein the second attachment is a weld. (5) the first attachment comprises an epoxy; 4. The delivery member of embodiment 3, wherein the second attachment comprises an epoxy.

[0068] (6) the first attachment is a first knot in the loop wire having a knot diameter approximately equal to the first diameter of the first attachment slot; A delivery member as described in embodiment 3, wherein the second attachment is a second knot in the loop wire having a diameter approximately equal to the first diameter of the second mounting slot. (7) The delivery member of embodiment 6, wherein the loop wire comprises a polymeric material. (8) The delivery member of embodiment 1, wherein the distal hypotube further comprises a spiral cut along a longitudinal axis through the lumen. (9) the first mounting slot is disposed on the distal hypotube opposite the second mounting slot along a diameter line passing through the longitudinal axis; 9. The delivery member of embodiment 8, wherein the first mounting slot is positioned proximal to the second mounting slot by a distance equal to half the pitch of the helical cut. (10) the first mounting slot is disposed at a first position equidistant from two adjacent ones of the spiral cuts; 9. The delivery member of embodiment 8, wherein the second mounting slot is positioned at a second position equidistant from two adjacent ones of the spiral cuts.

[0069] (11) The delivery member of embodiment 10, wherein the first mounting slot and the second mounting slot are disposed perpendicular to the longitudinal axis. (12) A distal hypotube for a delivery member, comprising: a distal end configured to receive an implantable medical device; a lumen extending through the distal hypotube; and a first attachment slot extending from the lumen to an outer surface of the distal hypotube; a second attachment slot extending from the lumen to the exterior surface; and a loop wire attached at a first end to the first mounting slot and attached at a second end to the second mounting slot; a spiral cut in the outer surface cut along a longitudinal axis through the lumen. (13) The first mounting slot has a distal end and a proximal end, the proximal end having a first diameter and the distal end having a second diameter, the first diameter of the first mounting slot being greater than the second diameter of the first mounting slot; the second mounting slot has a distal end and a proximal end, the proximal end having a first diameter and the distal end having a second diameter, the first diameter of the second mounting slot being greater than the second diameter of the second mounting slot; the loop wire is attached to the first mounting slot by a first attachment; 13. The distal hypotube of embodiment 12, wherein the loop wire is attached to the second mounting slot by a second attachment. (14) The loop wire comprises a metal material; the first attachment is a weld; 14. The distal hypotube of embodiment 13, wherein the second attachment is a weld. (15) The first attachment comprises an epoxy; 14. The distal hypotube of embodiment 13, wherein the second attachment comprises epoxy.

[0070] (16) the first attachment is a first knot in the loop wire having a first knot diameter approximately equal to the first diameter of the first attachment slot; 14. The distal hypotube of embodiment 13, wherein the second attachment is a second knot of the loop wire having a second knot diameter approximately equal to the first diameter of the second mounting slot. (17) The first mounting slot is disposed on the distal hypotube opposite the second mounting slot along a diameter line passing through the longitudinal axis; 13. The distal hypotube of embodiment 12, wherein the first mounting slot is positioned proximal to the second mounting slot by a distance equal to half the pitch of the helical cut. (18) A method of attaching an implantable medical device to a delivery member, comprising the steps of: providing the delivery member with a flexible distal hypotube; threading a first end of a loop wire through a proximal end of a first mounting slot of the flexible distal hypotube; pulling the first end of the loop wire from the proximal end of the first mounting slot toward a distal end of the first mounting slot, the distal end having a smaller diameter than the proximal end; Attaching the loop wire to the first attachment slot; threading a second end of the loop wire through a proximal end of a second mounting slot of the flexible distal hypotube; pulling the second end of the loop wire from the proximal end of the second mounting slot toward a distal end of the second mounting slot having a smaller diameter than the proximal end; and attaching the loop wire to the second attachment slot. (19) The method of embodiment 18, wherein attaching the loop wire to the first mounting slot includes welding the loop wire into the first mounting slot. (20) tying a first knot in the first end of the loop wire prior to pulling the first end of the loop wire from the proximal end of the first mounting slot toward the distal end of the first mounting slot; 19. The method of claim 18, further comprising tying a second knot in the second end of the loop wire before pulling the second end of the loop wire from the proximal end of the second mounting slot toward the distal end of the second mounting slot.

Claims

1. A distal hypotube for a delivery member, comprising: a distal end configured to receive an implantable medical device; a cylindrical lumen extending through the distal hypotube; a first attachment slot extending from the lumen to an outer surface of the distal hypotube; a second attachment slot extending from the lumen to the exterior surface; and an engagement system movable to engage and deploy the implantable medical device engaged to the distal end of the distal hypotube, the engagement system comprising: an engagement system comprising a loop wire attached at a first end to the first mounting slot via a first attachment and attached at a second end to the second mounting slot via a second attachment; a spiral cut in the outer surface cut along a longitudinal axis through the lumen; the first mounting slot is disposed on the distal hypotube diametrically opposite the second mounting slot along the longitudinal axis; The distal hypotube, wherein the first mounting slot is disposed proximally of the second mounting slot by a distance equal to half the pitch of the helical cut.

2. the first mounting slot has a distal end and a proximal end, the proximal end having a first diameter and the distal end having a second diameter, the first diameter of the first mounting slot being greater than the second diameter of the first mounting slot; 2. The distal hypotube of claim 1, wherein the second mounting slot has a distal end and a proximal end, the proximal end having a first diameter and the distal end having a second diameter, the first diameter of the second mounting slot being greater than the second diameter of the second mounting slot.

3. The distal hypotube of claim 2, wherein the spiral cuts are positioned on a single helix extending between the proximal and distal ends of the distal hypotube and rotating multiple times around the longitudinal axis.

4. The distal hypotube of claim 3, wherein the spiral cut has multiple cut portions and multiple uncut portions on the single spiral.

5. A distal hypotube as described in claim 4, wherein the proximal end of the first mounting slot and the proximal end of the second mounting slot are both positioned in the plurality of uncut portions.

6. The distal hypotube of claim 5, wherein the proximal end of the first mounting slot and the proximal end of the second mounting slot are positioned in different uncut portions of the plurality of uncut portions.

7. the loop wire comprises a metallic material; the first attachment is a weld; The distal hypotube of claim 2 , wherein the second attachment is a weld.

8. the first attachment comprises an epoxy; The distal hypotube of claim 2 , wherein the second attachment comprises an epoxy.

9. the first attachment is a first knot in the loop wire having a first knot diameter approximately equal to the first diameter of the first attachment slot; 3. The distal hypotube of claim 2, wherein the second attachment is a second knot in the loop wire having a second knot diameter approximately equal to the first diameter of the second mounting slot.

10. A delivery member for delivering the implantable medical device to a target location in a blood vessel of a body, the delivery member comprising: A proximal hypotube; a supporting coil section attached to a distal end of the proximal hypotube; 10. A delivery member comprising: a distal hypotube according to any one of claims 1 to 9; and wherein the engagement system extends through the lumen and engages the loop wire to engage the engagement system with the implantable medical device, the pull wire being movable proximally retracted to release the loop wire and deploy the implantable medical device.

11. The delivery member of claim 10 , wherein the loop wire comprises a polymeric material.

12. the first mounting slot is disposed at a first location equidistant from two adjacent ones of the spiral cuts; The delivery member of claim 10 , wherein the second mounting slot is disposed at a second location equidistant from two adjacent ones of the spiral cuts.

13. The delivery member of claim 12 , wherein the first mounting slot and the second mounting slot are disposed perpendicular to the longitudinal axis.

14. 1. A method of attaching an implantable medical device to a delivery member, comprising: Providing the delivery member with a distal hypotube according to any one of claims 1 to 9; threading the first end of the loop wire through a proximal end of the first mounting slot of the distal hypotube; pulling the first end of the loop wire from the proximal end of the first mounting slot toward a distal end of the first mounting slot, the distal end having a smaller diameter than the proximal end; Attaching the loop wire to the first attachment slot; threading the second end of the loop wire through a proximal end of the second mounting slot of the distal hypotube; pulling the second end of the loop wire from the proximal end of the second mounting slot toward a distal end of the second mounting slot having a smaller diameter than the proximal end; and attaching the loop wire to the second attachment slot.

15. The method of claim 14 , wherein mounting the loop wire in the first mounting slot comprises welding the loop wire into the first mounting slot.

16. tying a first knot in the first end of the loop wire prior to pulling the first end of the loop wire from the proximal end of the first mounting slot toward the distal end of the first mounting slot; 15. The method of claim 14, further comprising tying a second knot in the second end of the loop wire prior to pulling the second end of the loop wire from the proximal end of the second mounting slot toward the distal end of the second mounting slot.

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