Medical device delivery member having a flexible, stretch-resistant distal portion

Abstract

The invention is entitled "Medical device delivery member with flexible, stretch-resistant distal portion." The invention provides a delivery member for delivering and deploying an intravascular medical device. The delivery member includes a flexible distal portion that includes a coiled wire coil that is surrounded by a flexible sleeve and inhibited from extending in length by a stretch-resistant member positioned through a lumen of the coil. The delivery member can include hypotubes positioned on either side (distal and proximal) of the coiled wire coil, to which the stretch-resistant member and the coiled wire coil can be attached.

Description

Technical Field

[0001] The present invention generally relates to intravascular medical device systems that can be navigated through the body vessels of human subjects. More particularly, the present invention relates to delivery systems and delivery members for delivering and deploying implantable medical devices to target locations within body vessels and methods of using the same. Background Art

[0002] The use of catheter delivery systems to locate and deploy therapeutic devices such as inflatable balloons, stents, and embolic coils in the vascular system of the human body has become a standard procedure for treating intravascular diseases. It has been found that such devices are particularly suitable for treating areas where traditional operating procedures are impossible or pose a great risk to the patient, such as in the treatment of aneurysms in intracranial blood vessels. Because the tissue (e.g., brain tissue) surrounding the intracranial blood vessels is relatively fragile, performing surgical treatment of defects in the intracranial blood vessels can be difficult and often risky. Advances in catheter-based implant delivery systems provide alternative treatments in this context. Some advantages of catheter delivery systems are that they provide methods for treating blood vessels in a manner that has been found to reduce the risk of trauma to the surrounding tissues, and they also allow treatment of blood vessels that were previously considered inoperable.

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

[0004] Some challenges associated with properly executing such treatment protocols include ensuring that the delivery member and engagement system remain in a stable position throughout the treatment protocol. For example, in some aneurysm treatment applications, as the aneurysm becomes increasingly filled with embolic material, the delivery member may tend to shift due to increased pushback from the implanted embolic material. If the delivery member shifts during treatment, the physician may not be able to accurately control the placement of the embolic material and may choose to stop packing the aneurysm. In such examples, the aneurysm may not be adequately packed, which may result in recanalization. In addition, excessive movement or stretching of the delivery member and / or the engagement system thereon may result in premature detachment of the embolic coil.

[0005] Therefore, there is a need for improved methods, devices, and systems to provide implant delivery members and implant engagement systems with increased stability. Summary of the Invention

[0006] It is an object of the present invention to provide systems, devices, and methods that meet the above 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] When the distal end of the delivery member is advanced through the tortuous distal anatomy, the stiffness of the distal portion of the delivery member can cause the microcatheter used to deliver the embolic material to be pulled back from the aneurysm. If the microcatheter is pulled back while advancing the embolic material, the microcatheter may become disengaged from the aneurysm, and the physician may lose control of the embolic coil and be unable to accurately control the placement of the embolic material, and may not be able to complete the treatment.

[0008] Flexibility can be provided by incorporating a length of wound coil along the distal portion of the delivery member. The wound coil can be protected by a flexible polymer sleeve located outside the coil. The wound coil can be restrained from elongating by 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 may include a distal hypotube, a support coil segment, a proximal hypotube, a flexible sleeve covering the support coil segment, and an anti-stretch member extending across the support coil segment. The distal hypotube, the support coil segment, and the proximal hypotube may form a continuous tubular structure with a lumen passing therethrough. The flexible sleeve may cover some or all of the support coil segment to prevent radial expansion of the support coil segment and improve the ability of the support coil segment to slide through the vascular system. The anti-stretch member may be attached to the proximal hypotube and the distal hypotube, thereby extending across the entire support coil segment.

[0010] The delivery member may further include an engagement system that is movable to engage and deploy the implantable medical device. The engagement system may include a loop wire and a pull wire. The loop wire may extend through an opening in the implantable medical device, and the pull wire may engage the loop wire, thereby engaging the engagement system to the implantable medical device. The pull wire may be positioned within the lumen of the delivery member and may be retracted proximally to disengage the loop wire. Once disengaged from the pull wire, the loop wire may be movable to retract from the opening in the implantable medical device, thereby deploying the implantable medical device.

[0011] When the engagement system is moved to deploy the implantable medical device, at least a portion of the distal hypotube can be compressed and can extend as the engagement system is moved.

[0012] The support coil section may include a non-radiopaque proximal coil, a non-radiopaque distal coil, and a radiopaque central coil positioned between the non-radiopaque coils.

[0013] The support coil segment can be made of a wire that is wound to define a portion of the lumen of the delivery member.The wire from which the support coil is made can have a cross-sectional diameter of about 0.8 mil to about 5 mil (about 20 nm to about 130 nm).

[0014] The flexible sleeve may comprise a polymer. The flexible sleeve may comprise an additive to increase the lubricity of the polymer.

[0015] The flexible sleeve may be attached to the proximal hypotube and the distal hypotube. The flexible sleeve thus constructed may cover the entire coiled section and at least a portion of the proximal hypotube and / or at least a portion of the distal hypotube.

[0016] The stretch resistant member may be an extruded tube.

[0017] The support coil section and the distal hypotube may have a length, measured from the proximal end of the support coil to the distal end of the distal hypotube, of about 30 cm to about 50 cm, or more specifically, about 40 cm.

[0018] The proximal hypotube may include a helical cut portion near its distal end.

[0019] An exemplary method for designing or constructing a delivery member (such as the example described above) may include the following steps: selecting a first hypotube and a second hypotube; forming a wire coil segment between the two hypotubes; extending a stretch-resistant member through the lumen of the wire coil segment; attaching the stretch-resistant member to the first hypotube and the second hypotube; selecting a flexible sleeve; covering the support coil segment with the flexible sleeve; and attaching an implantable medical device to the distal end of the first hypotube so that the implantable medical device can be separated from the first hypotube during treatment.

[0020] The step of forming the wire coil section may include: forming a non-radiopaque proximal coil; forming a non-radiopaque distal coil; and forming a radiopaque central coil extending between the non-radiopaque proximal coil and the non-radiopaque distal coil. Alternatively, the support coil section does not need to include a radiopaque section. The step of forming the wire coil section may additionally or alternatively include selecting a wire having a diameter of about 0.8 mil to about 5 mils (about 20 mm to about 130 mm), and winding the wire to form the wire coil section and define the lumen of the wire coil section.

[0021] The step of selecting a flexible sleeve may include selecting a polymer sleeve having an additive to increase the lubricity of the polymer.

[0022] The step of extending the anti-tension member through the lumen of the wire coil tube can include extending a substantially tubular anti-tension member through the lumen of the wire coil tube.

[0023] The step of attaching the implantable medical device to the first hypotube can include compressing the first hypotube and attaching the implantable medical device to the distal end of the compressed first hypotube.

[0024] The exemplary method for designing or constructing a delivery member can also include positioning the loop wire within the lumen of the first hypotube and positioning the pull wire to extend through the lumen of the first hypotube, the wire coil segment, and the second hypotube. The step of attaching the implantable medical device can additionally or alternatively include extending the loop wire through an opening in the implantable medical device and engaging the pull wire to a portion of the loop wire that extends through the opening in the implantable medical device. The step of attaching the implantable medical device can additionally or alternatively include positioning the pull wire to extend proximally from the proximal end of the second hypotube. BRIEF DESCRIPTION OF DRAWINGS

[0025] The above aspects and additional aspects of the present application will be further discussed with reference to the following description and

[0026] In these drawings, like reference numbers generally indicate similar structural elements and features in the various figures. The drawings are not necessarily to scale, emphasis instead being placed on illustrating the principles of the application. The drawings depict one or more specific embodiments in accordance with the present application in example form.

[0027] Figure 1 is a diagrammatic representation of a cross-section of a delivery member in accordance with aspects of the present application;

[0028] Figure 2A is a diagrammatic representation of a cross-section of a flexible sleeve in accordance with aspects of the present application;

[0029] Figure 2B is a diagrammatic representation of a cross-section of an anti-tension tube in accordance with aspects of the present application;

[0030] Figure 2C is a diagrammatic representation of a cross-section of a wire coil attached to a distal hypotube and a proximal hypotube in accordance with aspects of the present application;

[0031] Figures 3A to 3D is a diagrammatic representation of an engagement system showing a sequence for deploying an implant in accordance with aspects of the present application;

[0032] Figure 4 is a flowchart showing a method for designing or constructing a delivery member in accordance with aspects of the present application; and

[0033] Figure 5is a flow chart illustrating a method of using a delivery system including an exemplary delivery member according to aspects of the present invention. DETAILED DESCRIPTION

[0034] During endovascular treatment (e.g., aneurysm occlusion treatment), a lack of flexibility in the distal portion of a delivery member of the treatment device can cause the delivery member to be pulled back from the treatment site or otherwise moved out of position while an implant or other medical treatment device is being placed in an aneurysm or other treatment site. Therefore, in addition to other applications facing similar challenges, delivery members and engagement systems with more flexible distal portions can provide a stable system for delivering medical devices in neurovascular anatomical structures. However, flexible structures can tend to deform, stretch, or expand when navigating tortuous anatomical structures. Deformation of the delivery member can inhibit the ability of the delivery member to navigate to the treatment site and / or effectively deploy the medical device. Elongation of the delivery member can lead to premature deployment of the medical device.

[0035] An object of the present invention is to provide a delivery member having a highly flexible distal portion that resists stretching and is structurally stable during the delivery and deployment of a medical therapeutic device. For ease of discussion, the medical therapeutic device will generally be referred to herein as an "implant," but as will be understood and appreciated by those of ordinary skill in the art, aspects of the present invention can be applied to the delivery and deployment of non-implanted medical devices.

[0036] According to the present invention, in some examples, a highly flexible distal portion of a delivery member can include a coiled wire, an outer sheath, and an inner stretch-resistant member. The coiled wire can be formed from a substantially linear wire wound into a coil shape and / or a hypotube laser cut in a spiral pattern. If the coiled wire is formed from laser-cut hypotube, the spiral can be free of interfering cuts connecting the windings in the coil to provide a more flexible coil. The outer sheath can inhibit radial deformation of the coiled wire and / or provide a smooth surface against which the vessel wall can slide during delivery of the implant. The stretch-resistant member can inhibit elongation of the coiled wire during delivery of the implant. Thus, the combination of the coiled wire, the outer sheath, and the stretch-resistant member can provide a distal portion of the delivery member that has greater flexibility and greater stability than at least some known delivery members.

[0037] Turn to the attached figure, as Figure 1As shown, the example delivery member 10 can include a proximal tube 100, a coiled segment 200, a distal tube 300, a sleeve 500 surrounding the coiled segment, and a stretch-resistant member 600 within the lumen of the coiled segment 200. The proximal tube 100 can extend most of the length of the delivery member 10, with the coiled segment 200 and the distal tube 300 forming a length sufficient to absorb most of the pushback that can occur during placement of an implant at a treatment site. In some examples, the length can be between about 30 cm and 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 coiled segment 200, and the coiled segment 200 can have a distal end 204 connected to a proximal end 302 of the distal coil 300.

[0038] Figure 2A is a cross-sectional view of the sleeve 500. Figure 2B is a cross-sectional view of the stretch-resistant member 600. Figure 2C is a cross-sectional view of the assembled proximal tube 100, coiled segment 200, and distal tube 300.

[0039] The coiled segment 200 can be formed separately from the proximal hypotube 100 and / or the distal hypotube 300. The separately formed coiled segment 200 can be attached to the proximal tube 100 and / or the distal tube 300 by welds 712, 714 or other suitable attachments. Alternatively or additionally, at least a portion of the coiled segment can be formed from a helical laser cut portion of a hypotube. By selecting a wire having a particular cross-section (e.g., circular) with a particular diameter D, or by selecting a wire having material properties that increase flexibility, the separately formed coiled segment 200 can be made more flexible than a helically cut tube. Conversely, by cutting a single hypotube to form the proximal tube 100, coiled segment 200, and distal hypotube 300, reducing or eliminating welds 712, 714 or other attachments, the laser cut portions can be more easily manufactured. In either case, the wire of the coil 200 can have a diameter D in a range including about 0.8 mil and 5 mil (about 20 nm to about 130 nm).

[0040] The coiled segment can be formed primarily of a non-radio-opaque material, such as steel, and can include a radio-opaque segment 216 made of a radio-opaque material, such as platinum and / or tungsten. The radio-opaque segment 216 can be positioned between a proximal, non-radio-opaque segment of the coil 212 and a distal, non-radio-opaque segment of the coil 214. The radio-opaque segment 216 can be positioned a predetermined distance from the distal end 304 of the delivery member 10 so that a physician can easily visualize placement of the distal portion of the delivery member during a treatment procedure. The proximal segment 212, the radio-opaque segment 216, and the distal segment 214 can be welded concentrically.

[0041] The coiled section 200 may be surrounded by a flexible sleeve or fused sheath 500 (collectively referred to herein as a "sleeve"). The sleeve may inhibit the coil 200 from radially expanding and / or engaging with the vessel wall during navigation. The sleeve 500 may comprise a polymer. The polymer may comprise an additive to increase the lubricity of the sleeve 500 so that the sleeve may slide easily through the body vessel. Figure 2A As shown, the sleeve 500 can have a wall thickness T measured within a range including about 0.5 mil and about 2 mils (about 0.01 mm to about 0.05 mm). The sleeve 500 can be further coated with a hydrophilic coating to further minimize friction during intravascular navigation. The sleeve 500 can be fused or glued to the coil 200, the proximal hypotube 100, and / or the distal hypotube 300.

[0042] The stretch-resistant member 600 can be positioned to inhibit elongation of the coil 200 during intravascular navigation. The stretch-resistant member 600 can include a tube sized to fit within 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, extending within the lumen 108 of the proximal tube 100 and within the lumen 308 of the distal coil 300. The stretch-resistant member 600 can be attached to the proximal tube 100 and the distal tube 300 at adhesive joints 702, 704 or other suitable attachments. The stretch-resistant member 600 can remain unattached to the coiled section 200, allowing the stretch-resistant member 600 and the coiled section 200 to move somewhat independently of each other.

[0043] The delivery member 10 may include a mechanical engagement system for engaging the medical therapeutic device during delivery, which can be mechanically actuated to deploy the therapeutic device. The mechanically actuated engagement system typically includes one or more internal elongated members or puller wires extending through the delivery member that can be manipulated by a physician at their proximal ends to deploy the medical therapeutic device. Such wires or internal elongated members are generally referred to herein as "puller wires."

[0044] Figures 3A to 3D The delivery member 10 is shown to include a mechanical engagement system comprising a puller 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 moved to release the medical treatment device from the delivery member 10. The loop wire 400 can be attached to the distal tube 300 by welding 408 or other suitable attachments (see FIG. Figure 1). The tensile 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 coiled segment 200, and the distal tube 300. For example, the tensile resistant member 600 can be tubular with a lumen therethrough, and the pull wire 140 can extend through the lumen of the tubular tensile resistant member 600. During manufacture of the tensile resistant member 600, the tensile resistant member 600 can be extruded over the pull wire 140.

[0045] The combination of the coil 200, the sleeve 500, and the tensile resistant member 600 can provide a highly flexible distal portion of the delivery member 10 that is suitable for navigating tortuous anatomy, including neurovascular. The tensile resistant member 600 can support the coil 200 to prevent the coil 200 from extending significantly during navigation of the blood vessel, thereby reducing tension on the pull wire 140 extending therethrough and reducing the likelihood of premature deployment of the attached medical treatment device.

[0046] The proximal tube 100 can include a flexible segment 106 that has material removed to increase flexibility of the flexible segment 106. The flexible segment 106 can be cut in a helical pattern. The helical pattern of the flexible segment 106 can be free of interfering cuts that connect the inner windings of the helix. The tensile resistant member 600 can extend through the flexible segment 106 and be attached to the proximal tube 100 in a proximal direction from the flexible segment 106. The tensile resistant member 600 can thereby inhibit elongation of the flexible segment 106 and the coiled segment 200 of the proximal tube 100. The sleeve 500 can cover at least a portion of the flexible segment 106 to inhibit deformation of the flexible segment and / or reduce friction with the vasculature and the flexible segment 106 during intravascular navigation. In some examples, the sleeve 500 can cover about 10 cm of the proximal tube 100, proximate and / or including the distal end 104 of the proximal tube 100.

[0047] The distal tube 300 can include a compressible portion 306. The compressible portion 306 can be axially adjustable between an elongated state and a compressed state. The compressible portion 306 can be formed from a helical cut portion of the tube 300 formed by a laser cutting operation. Additionally or alternatively, the compressible portion can be formed from a coiled wire, a helical ribbon, or other arrangement according to the present invention that allows for axial adjustment. Preferably, the compressible portion 306 is in the elongated state when at rest and automatically or elastically returns to the elongated state from the compressed state, unless otherwise limited.

[0048] Figures 3A to 3D The detachment of the medical device 12 using a mechanical engagement / deployment system is shown. Figure 3AThe engagement system 140, 400 is shown locked into the locking portion 18 of the medical device 12. The compressible portion 306 of the distal tube 300 can be compressed, and the loop 400 opening 405 at the distal end 404 of the loop 400 can be placed through the locking portion 18. When the pull wire 140 is passed through the opening 405, the medical device 12 is now secured. Figure 3B Pull wire 140 is shown being pulled proximally to initiate a release sequence of medical device 12 . Figure 3C The moment when the pull wire 140 leaves the opening 405 and is pulled out of the loop 400 is shown. The distal end 404 of the loop 400 breaks away from and leaves the locking portion 18. As can be seen, there is now nothing holding the medical device 12 from the detachment system 10. Figure 3D The end of the release sequence is shown. Here, the compressible portion 306 has extended / recovered to its original shape and "popped" forward. The distal end 304 of the distal tube 300 applies a spring force E to the medical device 12 to "push it away," thereby ensuring complete separation and delivery of the medical device 12.

[0049] The illustrations in the above-mentioned figures depict generally hollow or tubular structures 100, 200, 300, 500, 600 according to the present invention. As used herein, the terms "tubular" and "tube" should be understood broadly and are not limited to structures that are perfectly cylindrical or have a completely circular cross-section or a uniform cross-section throughout their length. For example, tubular structures or systems are generally shown as structures that are substantially perfectly cylindrical. However, tubular systems may have tapered or curved outer surfaces without departing from the scope of the present invention.

[0050] Figure 4 is a flow chart including method steps for constructing or designing a delivery member such as the exemplary delivery members described herein. Figure 4 8. In the method 800 outlined in FIG. 8, 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 a proximal hypotube 100 as described herein or as known to one of ordinary skill in the art. The second hypotube can be a distal hypotube 300 as described herein or as known to one of ordinary skill in the art. The flexible sleeve can be a sleeve or fusion sheath 500 as described herein or as known to one of ordinary skill in the art. The wire coil can include a support coil, a coiled section 200 as described herein or as 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 known to one of ordinary skill in the art.

[0051] In step 820, the 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 each other. 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 that will be understood by a person of ordinary skill in the art. Steps 820, 830, and 840 do not need to be performed in this order, but can be performed simultaneously. For example, as indicated by step 840, the stretch-resistant member can be attached to one of the first and second hypotubes, and then as indicated by step 830, the hypotube to which the stretch-resistant member is attached can be attached to the wire coil, and then as indicated by step 820, the stretch-resistant member can be positioned through the wire coil, and then as indicated by step 830, the other of the hypotubes can be attached to the wire coil, and then as indicated by step 840, the stretch-resistant member can be attached to the other hypotube.

[0052] In 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, in step 850, the flexible sleeve may also be positioned to cover at least a portion of the flexible section.

[0053] In step 860, the implant can be removably attached to the distal end of the first hypotube. In step 860, the implant can be attached by positioning a loop wire within the first hypotube, positioning a pull wire to extend through the first hypotube, coiling the wire and the second hypotube, and securing the implant with the loop wire and the pull wire. The pull wire can extend from the proximal end of the second hypotube. If the first hypotube has a compressible portion, the compressible portion can be compressed in step 860, and the implant can be attached to the delivery member while the compressible portion is compressed.

[0054] Figure 5 is a flow chart including method steps for administering intravascular therapy using a system including a delivery member, such as the exemplary delivery members described herein. Figure 5 In the method 900 outlined in FIG. 1 , a system having a distal hypotube, a proximal hypotube, a coiled segment coaxially positioned between the hypotubes, a flexible sleeve covering the coiled segment, a stretch-resistant member positioned within the coiled segment, and a medical treatment device attached to or proximate the distal hypotube can be selected at step 910. The system can be suitable for intravascular treatment as described and illustrated herein or as known to one of ordinary skill in the art.

[0055] In step 920, the system can be moved through a catheter to a treatment site, such as an aneurysm or other abnormality in a blood vessel. In step 930, the system can bend as it is moved through the catheter. In step 940, the coiled section of the system can be prevented from deforming by a flexible sheath and a stretch-resistant member; the flexible sheath can inhibit radial deformation of the coiled section, while the stretch-resistant member can inhibit longitudinal extension of the coil.

[0056] In step 950, the medical treatment device can be deployed. If the medical treatment device is an implant, the implant can be detached in step 950. In step 960, the distal tube can be extended to push the medical treatment device away from the distal tube. If the medical treatment device is the implant detached in step 950, the detached implant can be ejected from the distal tube in response to the expansion of the distal tube in step 960.

[0057] The descriptions contained herein are examples of embodiments of the present invention and are not intended to limit the scope of the invention in any way. As described herein, the present invention contemplates numerous variations and modifications of the delivery system, delivery member, and engagement system, including alternative configurations of components, alternative materials, alternative medical treatment devices, alternative means for deploying medical treatment devices, alternative geometries of individual components, alternative means for attaching assembly components, and the like. Such modifications will be apparent to one of ordinary skill in the art to which the present invention relates and are intended to fall within the scope of the appended claims.

Claims

1. A delivery member for delivering an implantable medical device to a target location in a body vessel, the delivery member comprising: a distal hypotube comprising a distal end shaped to receive the implantable medical device; a support coil section terminating in a proximal-most end and a distal-most end, the distal-most end being directly attached to the proximal-most end of the distal hypotube; a proximal hypotube having a distal-most end directly attached to the proximal-most end of the support coil section; a lumen extending through the distal hypotube, the support coil section, and the proximal hypotube; a flexible sleeve covering at least a majority of an outer surface of the support coil section; and A stretch-resistant member extends through a portion of the lumen, the stretch-resistant member being attached to the proximal hypotube and to the distal hypotube.

2. The delivery member of claim 1 , further comprising: an engagement system movable to engage and deploy the implantable medical device engaged at the distal end of the distal hypotube, the engagement system comprising: a loop wire extending through an opening in the implantable medical device, thereby engaging the engagement system to the implantable medical device, and movable to be retracted from the opening in the implantable medical device to deploy the implantable medical device, and A puller wire extends through the lumen, is engaged to the loop wire, thereby engaging the engagement system to the implantable medical device, and is movable to retract proximally to disengage the loop wire to deploy the implantable medical device.

3. The delivery member according to claim 2, in, The distal hypotube includes a compressible portion movable from a compressed state to an extended state, and Wherein the engagement system maintains the compressible portion in the compressed state when engaged to the implantable medical device.

4. The delivery member of claim 1, wherein The support coil section comprises: a non-radiopaque proximal coil extending from the proximal end of the support coil section; a non-radiopaque distal coil extending from the distal end of the support coil section; and A radiopaque central coil extends between the non-radiopaque proximal coil and the non-radiopaque distal coil.

5. The delivery member of claim 1, wherein The support coil section comprises: A wire is wound to form the support coil section and define a portion of the lumen, the wire having a diameter from 0.0008 inches to 0.005 inches.

6. The delivery member according to claim 1, in, The flexible sleeve comprises a polymer, and wherein the flexible sleeve includes an additive effective to increase the lubricity of the polymer.

7. The delivery member of claim 1, wherein: The flexible sleeve is attached to the proximal hypotube and the distal hypotube.

8. The delivery member of claim 1, wherein The stretch resistant member is an extruded tube.

9. The delivery member of claim 1, wherein: The delivery member has a length measurable from the proximal end of the support coil section to the distal end of the distal hypotube, and wherein the length is 40 cm.

10. The delivery member of claim 1, wherein The proximal hypotube includes a helical cut portion proximate a distal end of the proximal hypotube.

11. A method of constructing a delivery member for delivering an implantable medical device, the method comprising: selecting a first hypotube comprising a first lumen therethrough; selecting a second hypotube comprising a second lumen therethrough; forming a wire coil segment extending completely between the distal-most end of the second hypotube and the proximal-most end of the first hypotube, such that the distal-most end of the wire coil segment is directly attached to the proximal-most end of the first hypotube and the proximal-most end of the wire coil segment is directly attached to the distal-most end of the second hypotube, and the wire coil segment defines a third lumen therethrough; extending a stretch-resistant member through the third lumen; attaching the stretch-resistant member to the first hypotube and the second hypotube; Select flexible casing; covering at least a majority of the outer surface of the wire coil section with the flexible sleeve; as well as The implantable medical device is removably attached to the delivery member proximate the distal end of the first hypotube.

12. The method of claim 11 , wherein the step of forming the wire coil section further comprises: forming a non-radiopaque proximal coil extending distally from the distal end of the second hypotube; forming a non-radiopaque distal coil extending proximally from the proximal end of the first hypotube; as well as A radiopaque central coil is formed extending between the non-radiopaque proximal coil and the non-radiopaque distal coil.

13. The method of claim 11 , wherein the step of forming the wire coil section further comprises: Selecting a wire having a diameter from 0.0008 inches to 0.005 inches; as well as The wire is wound to form the wire coil section and define the lumen therethrough.

14. The method of claim 11 , wherein the step of selecting the flexible sleeve further comprises: A flexible sleeve is selected that includes a polymer and an additive effective to increase the lubricity of the polymer.

15. The method of claim 11, wherein the step of extending a stretch-resistant member through the third lumen further comprises: The substantially tubular stretch-resistant member is extended through the third lumen.

16. The method of claim 11, wherein the step of removably attaching the implantable medical device to the delivery member proximate the distal end of the first hypotube further comprises: compressing the first hypotube; as well as The implantable medical device is removably attached to the delivery member proximate the distal end of the compressed first hypotube.

17. The method according to claim 11, further comprising: positioning a loop wire within the first lumen; as well as positioning a puller wire to extend through the first lumen, the third lumen, and the first lumen, The step of detachably attaching the implantable medical device to the distal end of the first hypotube further comprises: extending the loop wire through an opening in the implantable medical device; as well as The puller wire is joined to a portion of the loop wire that extends through the opening in the implantable medical device.

18. The method of claim 17, wherein the step of removably attaching the implantable medical device to the distal end of the first hypotube further comprises: The puller wire is positioned to extend proximally from the proximal end of the second hypotube.

Images