Puller wire separation for intravascular devices

Abstract

The present invention is entitled "Pull Wire Detachment for Intravascular Devices". The present invention discloses an assembly at the proximal end of an intravascular delivery system that allows the proximal end of the pull wire to move independently of the delivery tube. The assembly may generally include a pull wire, a delivery tube, a feature for preventing the proximal end of the pull wire from becoming inaccessible due to distal movement of the pull wire, and a feature for protecting the proximal end of the pull wire from accidental premature manipulation. As the intravascular delivery system navigates along a tortuous vascular system, the proximal end of the pull wire may move distally relative to the proximal end of the delivery tube, thereby eliminating stress on the distal end of the pull wire. The proximal end of the pull wire may be protected from accidental manipulation during delivery and made available for manipulation once the distal end of the delivery system is in the proper position.

Description

Technical Field

[0001] The present invention relates generally to medical devices and, more particularly, to deploying intravascular implants. Background Art

[0002] Many intravascular implant devices and clot capture devices are known in the art. Many devices are mechanically deployed and manipulated via a system that combines one or more catheters and lines for delivery. Examples of mechanically deliverable implants include embolic elements, stents, grafts, drug delivery implants, flow deflection elements, filters, stimulation leads, sensing leads, or other implantable structures delivered by microcatheters. Some obstetric and gastrointestinal implants can also be implanted via a similar system that combines one or more catheters and lines. Devices that can be released, deployed, or otherwise manipulated by mechanical means have significant differences in design, but similar delivery catheter and line systems can be used.

[0003] Many such catheter-based implant delivery systems include one or more inner elongated members extending through the catheter, which can be manipulated by a physician at the proximal end to deploy the implant. The inner elongated member can be held in the catheter until the time for releasing the implant. These systems can be actuated by retracting or pulling the one or more elongated members relative to the catheter. Such lines or inner elongated members are generally referred to as "pull wires" in this article.

[0004] Premature release of the implant while passing through the vascular system or before implantation is complete can lead to complications. Reducing the likelihood of premature release may come at the expense of a less flexible mechanical release system. For example, when delivering an embolic coil using a release system as described in U.S. Patent No. 8,062,325 or as described in U.S. Patent Application No. 15 / 964,857 (each incorporated herein by reference), it is desirable to have a puller wire extending within the embolic coil of minimal length in order to minimize stiffening of the proximal end of the coil. However, if significant proximal movement of the puller wire occurs while passing the delivery system through the vascular system, this limited engagement can lead to premature separation of the coil.

[0005] Therefore, there is a need for systems, devices, and methods that can reduce the likelihood of premature deployment of intravascular therapeutic devices while also providing a flexible mechanical release system. Summary of the Invention

[0006] An object of the present invention is to provide systems, devices and methods that meet the above needs. Generally speaking, an object of the present invention is to provide an intravascular delivery system having a component at the proximal end of the puller wire that allows the proximal end of the puller wire to move independently of the delivery tube and a method for using and manufacturing the intravascular delivery system to meet the above needs. The component may generally include a puller wire, a delivery tube, a feature for preventing the proximal end of the puller wire from becoming inaccessible due to distal movement of the puller wire, and a feature for protecting the proximal end of the puller wire from accidental premature manipulation. When the intravascular delivery system is navigated along a tortuous vascular system, the proximal end of the puller wire can move distally relative to the proximal end of the delivery tube, thereby eliminating stress on the distal end of the puller wire. The proximal end of the puller wire can be protected from accidental manipulation during delivery and the proximal end of the puller wire can be used for manipulation once the distal end of the delivery system is in the proper position.

[0007] In some examples, the feature that prevents the proximal end of the puller wire from becoming inaccessible can include a combination of a lug positioned on the proximal end of the puller wire and an intermediate hypotube extending from the proximal end of the delivery tube and providing an engagement surface sized to inhibit the lug from entering the intermediate hypotube. Thus, except when the lug engages the engagement surface of the intermediate hypotube (in which case distal movement of the puller wire is inhibited), the proximal end of the puller wire can thereby freely move proximally and / or distally relative to the hypotube.

[0008] In some examples, the intermediate hypotube may be stretchable. In such examples, the feature that protects the proximal end of the puller wire from inadvertent manipulation may include a detachable attachment that prevents the intermediate hypotube from stretching during delivery of the intravascular therapeutic device. To deploy the intravascular therapeutic device, the detachable attachment may be detached, the intermediate hypotube may be stretched, and upon stretching, the proximal end of the puller wire may engage the intermediate hypotube, and upon further stretching, the proximal end of the puller wire may move in a proximal direction. Sufficient movement of the proximal end of the puller wire may result in proximal translation of the distal end of the puller wire. Sufficient proximal translation of the distal end of the puller wire may result in deployment of the intravascular therapeutic device.

[0009] In some examples, the feature that protects the proximal end of the puller wire from accidental manipulation may include a sheath surrounding the proximal end of the puller wire. The sheath may be attached to the intermediate hypotube and positioned around the proximal end of the puller wire. To deploy the intravascular therapeutic device, the sheath may be grasped and pulled proximally relative to the delivery tube to cause the intermediate hypotube to stretch, thereby causing the puller wire to engage the intermediate hypotube and translate proximally.

[0010] According to the present invention, an exemplary intravascular delivery system may include a delivery tube, an intermediate hypotube, and a puller wire. The intravascular device may be adapted to deliver an intravascular therapeutic device through a patient's blood vessel to a treatment site. To this end, the delivery tube may be sized for delivery through the patient to the treatment site. During treatment, the intermediate hypotube may be positioned external to the patient's body and need not be adapted to access the patient's vasculature.

[0011] The intermediate hypotube can be attached to the delivery tube and can extend proximally from the proximal end of the delivery tube. A puller wire can extend through the lumens of both the intermediate hypotube and the delivery tube. An engagement lug can be attached to the puller wire and positioned proximally relative to the proximal end of the intermediate hypotube.

[0012] The intravascular delivery system can further comprise a sheath attached to the intermediate hypotube. The sheath can surround the engagement lugs and the proximal portion of the puller wire.

[0013] The engagement lug may be movable in a distal direction relative to the proximal end of the intermediate hypotube. A stretch-eliminating gap between the engagement lug and the intermediate hypotube may define a travel length that the engagement lug may move in a distal direction before engaging the intermediate hypotube.

[0014] The intravascular therapeutic device can be positioned at the distal end of the intravascular delivery system. The puller wire can be movable to deploy the intravascular therapeutic device.

[0015] The distal end of the intermediate hypotube can be positioned within the lumen of the delivery tube. The intermediate hypotube can include an extendable section. The extendable section can be positioned within the lumen of the delivery tube.

[0016] An exemplary method of assembling an intravascular delivery system may include one or more of the following steps, presented in no particular order, and the method may include additional steps not included herein. A delivery tube, an intermediate hypotube, and a puller wire may be provided. The delivery tube may be sized for delivery through a patient's vasculature. The provided delivery tube and intermediate hypotube may each have respective lumens therethrough.

[0017] The intermediate hypotube can be attached to the delivery tube such that the intermediate hypotube extends in a proximal direction from the proximal end of the delivery tube.

[0018] To attach the intermediate hypotube to the delivery tube, the distal end of the intermediate hypotube may be attached within the lumen of the delivery tube.

[0019] The intermediate hypotube may be provided with a strain relief section. To attach the intermediate hypotube to the delivery tube, the strain relief section may be positioned within the lumen of the delivery tube, a portion of the intermediate hypotube distally from the strain relief section may be attached to the delivery tube, and a portion of the intermediate hypotube proximally from the strain relief section may be detachably attached to the delivery tube.

[0020] An engagement lug may be formed at the proximal end of the puller wire. The puller wire may be positioned such that the engagement lug is proximally located relative to the proximal end of the intermediate hypotube, and the length of the puller wire extends through the lumens of the intermediate hypotube and the delivery tube. The engagement lug may be sized to inhibit movement of the engagement lug into the lumen of the intermediate hypotube.

[0021] The puller wire can be positioned such that a distal end of the puller wire is fixed relative to the distal end of the delivery tube and a proximal end of the puller wire is slidably translatable relative to the proximal end of the delivery tube. The distal end of the puller wire can be positioned to secure an intravascular treatment device at the distal end of the delivery tube.

[0022] A stretch relief gap may be provided such that the stretch relief gap defines a length by which the engagement lug may move in a distal direction relative to the intermediate hypotube without engaging the intermediate hypotube.

[0023] A sheath having a lumen therethrough may also be provided. The sheath may be attached to the intermediate hypotube. The engagement lug may be positioned within the lumen of the sheath.

[0024] An exemplary method of deploying an intravascular therapeutic device may include one or more of the following steps, presented in no particular order, and the method may include additional steps not included herein. The intravascular delivery system may be selected such that the selected delivery system includes a delivery tube, an intermediate hypotube extending from a proximal end of the delivery tube, and a pull wire extending through the lumens of the delivery tube and the intermediate hypotube. The intravascular delivery system may be extended through the vasculature of a patient. The proximal end of the pull wire may be permitted to move in a distal direction relative to the proximal end of the delivery tube as the delivery system is extended through the patient. The intravascular therapeutic device may be deployed by moving the proximal end of the pull wire in a proximal direction relative to the proximal end of the delivery tube.

[0025] The puller wire may have a bead positioned at or near the proximal end of the puller wire, and the bead may be engaged to the proximal end of the intermediate hypotube, thereby inhibiting the proximal end of the puller wire from entering the lumen of the intermediate hypotube.

[0026] The proximal end of the puller wire may be surrounded by a sheath. To deploy the intravascular treatment device, the sheath may be moved in the proximal direction relative to the delivery tube. Movement of the sheath may cause the intermediate hypotube to extend. The extension of the intermediate hypotube may cause the proximal end of the puller wire to engage with the intermediate hypotube. When the proximal end of the puller wire is engaged with the intermediate hypotube, the proximal end of the puller wire may be moved in the proximal direction relative to the proximal end of the delivery tube by extending the intermediate hypotube. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The above and other aspects of the present invention will be further discussed with reference to the following description in conjunction with the accompanying drawings, in which like numbers indicate similar structural elements and features in the various figures. The drawings are not necessarily drawn to scale, with emphasis instead being placed on illustrating the principles of the invention. The drawings depict one or more embodiments of the apparatus of the present invention by way of example only and not limitation.

[0028] Figure 1 is a diagrammatic representation of an intravascular delivery system and an intravascular implant according to aspects of the present invention;

[0029] Figure 2 According to various aspects of the present invention, Figure 1 Illustration of the proximal components of the indicated intravascular delivery system;

[0030] Figure 3 is an illustration of a delivery system for navigating along a body lumen according to aspects of the present invention;

[0031] Figures 4A to 4D According to aspects of the present invention, when a delivery system such as Figure 3 When navigating through a bend in a body cavity, such as Figure 2 Illustration of the proximal components of the intravascular delivery system shown;

[0032] Figure 5A and Figure 5B is an illustration of a proximal component of an intravascular delivery system according to aspects of the present invention, the intravascular delivery system being manipulated for deploying a therapeutic device;

[0033] Figure 5C is a diagram of an intravascular delivery system according to aspects of the present invention, the intravascular delivery system responding to the same conditions as in FIG5A and FIG5B . Figure 5B The implant is deployed by manipulation of the proximal components similar to those shown;

[0034] Figure 6 is a flow chart outlining the method steps for designing and / or constructing a delivery system according to aspects of the present invention; and

[0035] Figure 7 is a flow chart outlining the method steps for treating a patient using an intravascular delivery system according to aspects of the present invention. DETAILED DESCRIPTION

[0036] In at least some known intravascular delivery systems with a retractable puller wire, the proximal end of the puller wire is substantially fixed relative to the proximal end of the delivery tube, the distal end of the puller wire is attached to the therapeutic device deployment system, and the majority of the length of the puller wire is free to move within the confines of the lumen of the delivery tube. When such a delivery system is navigated along tortuous anatomical structures, the length of the puller wire may tend to extend into the outer curvature of the lumen of the delivery tube, thereby generating strain forces on the attached proximal and distal ends of the puller wire. If the proximal end of the puller wire is firmly fixed relative to the delivery tube, the strain may cause the distal end of the puller wire to move proximally. Significant proximal movement of the distal end of the puller wire may result in premature deployment of the implant or therapeutic device.

[0037] In the examples described herein, a slack mechanism can be built into the proximal end of the intravascular delivery system to allow the proximal end of the puller wire to move more freely than the distal end of the puller wire. When the exemplary delivery system is navigated through tortuous anatomical structures, the proximal end of the puller wire can move distally relative to the proximal end of the delivery tube to relieve strain on the distal end of the puller wire, thereby reducing the possibility of premature deployment of an implant or therapeutic device compared to existing intravascular delivery systems.

[0038] The accompanying drawings illustrate generally hollow or tubular structures according to the present invention. As used herein, the terms "tubular" and "tube" are to be understood broadly and are not limited to structures that are perfectly cylindrical, have a completely circular cross-section, or have a uniform cross-section throughout their length. For example, tubular structures or systems are typically illustrated as substantially perfectly cylindrical structures. However, tubular systems may have tapered or curved outer surfaces without departing from the scope of the present invention.

[0039] Figure 1 FIG is a diagram of an exemplary intravascular delivery system 100. The system may include an assembly at its proximal end for providing strain relief at the distal end 154 of the puller wire 150. The assembly is Figure 2 The delivery system 100 may include a delivery tube 110, a loop wire 140 attached to the delivery tube 110 near the distal end 114 of the delivery tube 110, an intermediate hypotube 130 extending from the proximal end 112 of the delivery tube 110, and a pull wire 150. The delivery system 100 may secure an intravascular treatment device 200 (such as an embolic coil 210) at the distal end 104 of the delivery system 100 for delivery to a treatment site, and the delivery system 100 may deploy the intravascular treatment device 200 by pulling the pull wire 150 proximally. Figure 1 In FIG, the delivery tube 110 is shown in cross-section. Figure 2 , the delivery tube 110 and the intermediate hypotube 130 are shown in cross-section.

[0040] The therapeutic device 200 may include an engagement feature 230, such as a key. The engagement feature may include an opening positioned at the proximal end of the therapeutic device 200. The therapeutic device 200 may be secured to the delivery system 100 by feeding a portion of the loop wire 140 through the opening of the engagement feature 230 and extending the distal end 154 of the puller wire 150 through the loop wire 140.

[0041] To deploy the treatment device 200, the puller wire 150 can be pulled proximally such that the distal end 154 of the puller wire exits the opening in the loop 140, thereby disengaging the loop 140. Once the loop 140 is disengaged from the puller wire 150, the loop 140 is free to exit the opening in the engagement feature 230.

[0042] The delivery tube 110 can include a compressible section 118. The compressible section 118 can be under compression such that once the loop 140 is disengaged, the compressible section 118 can decompress, thereby providing a force distally against the therapeutic device 200. The loop 140 can be sufficiently flexible such that when a force is provided by decompressing the compressible section 118, the loop moves out of the opening of the engagement feature 230, thereby separating the therapeutic device 200 from the delivery system 100. The force provided by the compressible section 118 during decompression can also push the implant 200 distally away from the distal end 104 of the delivery system 100, thereby creating a separation between the delivery system 100 and the therapeutic device 200.

[0043] Figure 2 is an illustration of an exemplary assembly at the proximal end of the intravascular delivery system 100 for providing strain relief at the distal end 154 of the puller wire 150 when the distal end 154 of the puller wire 150 is positioned to secure the therapeutic device 200 to the delivery system 100. The distal end 154 of the puller wire 150 may be positioned relative to Figure 1 The therapeutic device 200 is secured to the delivery system 100 as described or by other means that cause the therapeutic device 200 to deploy when the puller wire 150 is moved proximally.

[0044] The components at the proximal end of the delivery system 100 may include a puller wire 150, a delivery tube 110, an intermediate hypotube 130, and a sheath 170. The puller wire 150 may extend within the delivery tube 110, the intermediate hypotube 130, and the sheath 170. The intermediate hypotube 130 may be attached to the delivery tube 110 and extend proximally therefrom. The puller wire 150 need not be securely connected to the intermediate hypotube 130, but rather the proximal end of the puller wire 150 may be beaded such that a stretch-relieving gap 190 exists between the bead and the proximal end of the intermediate hypotube 130. The gap 190 may allow the proximal end of the puller wire 150 to move relative to the proximal end 112 of the delivery tube 110 and the intermediate hypotube 130 during traversal of tortuous anatomy, thereby minimizing the possibility of premature retraction of the puller wire 150 at its distal end.

[0045] The puller wire 150 can have a bead, lug, extension, protrusion, or other feature (generally referred to herein as a "bead") 156 at its proximal end 152 that extends radially beyond an outer circumference 158 of the puller wire 150 to a size that inhibits the bead 156 from entering the lumen 136 of the intermediate hypotube 130. The intermediate hypotube 130 can have a proximal end 132 positioned a gap distance 190 from the bead. The proximal end 132 of the intermediate hypotube 130 can be sized to maintain a position distal to the proximal end of the puller wire 150 such that if the gap 190 collapses during manipulation of the delivery system, the bead 156 is inhibited from entering the intermediate hypotube 130.

[0046] Alternatively, the intermediate hypotube 130 may include an alternative engagement feature, such as a plug in the lumen of the intermediate hypotube. In this case, the bead 156 may be sized to enter the lumen 136 of the intermediate hypotube 130, and the alternative engagement feature may prevent the bead 156 from moving further distally into the lumen 136. In such an example, the gap distance 190 may be understood as the length that the bead 156 may travel in the distal direction relative to the proximal end 112 of the delivery tube 110 before engaging the alternative engagement feature.

[0047] The assembly may also include a sheath 170 to cover the proximal portion of the puller wire 150 that extends out of the intermediate hypotube 130 to prevent accidental manipulation and / or breakage of the puller wire 150. The sheath 170 may be attached to the intermediate hypotube portion 130 using welds, glue, an interference fit, or other means 178. The sheath 170 may have a lumen 176 sized to fit over the proximal end 132 of the intermediate hypotube 130 and the outer circumference of at least a portion of the intermediate hypotube 130. The surface within the lumen 176 of the sheath 170 may be detachably attached to the outer surface of the intermediate hypotube 130.

[0048] The intermediate hypotube 130 may be attached to the delivery tube 110 using welds, glue, an interference fit, or other means 124. The intermediate hypotube 130 may have an outer circumference sized to fit within the lumen of the delivery tube 110. The outer surface of the intermediate hypotube 130 may be attached to the inner surface of the lumen 116 of the delivery tube 110 such that the intermediate hypotube 130 is not easily separated from the delivery tube 110 during a treatment protocol.

[0049] The intermediate hypotube 130 can have an extendable section 138 positioned within the lumen 116 of the delivery tube 110. The extendable section 138 can be stretched during a treatment protocol to lengthen the intermediate hypotube 130. The intermediate hypotube 130 can be attached to the delivery tube 110 at an attachment point 124 located in the distal direction 14 relative to the extendable section 138 such that when the extendable section 138 is stretched, the intermediate hypotube 130 extends further in the proximal direction 12 from the proximal end 112 of the delivery tube 110.

[0050] To prevent premature elongation of the intermediate hypotube 130 , it may be attached to the delivery tube 110 on the proximal side of the extendable section 138 near the proximal end 112 of the delivery tube 110 using a breakable attachment 122 .

[0051] The extendable section 138 may include an area of ​​the intermediate hypotube 130 where a section has been cut or removed. By way of illustration, Figure 2 A strain relief section 138 is shown having a helical cut in the hypotube 130 .

[0052] The intermediate hypotube 130 can have a length that is significantly shorter than the length of the delivery tube 110. During treatment, the proximal end 112 of the delivery tube 110 can be positioned outside the patient's body, while the distal end 114 of the delivery tube is positioned inside the patient near the treatment site. While the delivery tube 110 is positioned as described, the proximal end 132 of the intermediate hypotube 130 can be positioned outside the patient's body, and the intermediate hypotube 130 need not extend into the patient's body.

[0053] Figure 3The implant 200 (such as an embolic coil suitable for aneurysm treatment), the guide catheter 300, and the delivery system 100 including the delivery tube 110 and the puller wire 150 are shown positioned within tortuous vasculature (the vasculature is not shown). At bends A, B, and C, the delivery tube 110 can extend to the sidewall of the guide catheter 300 on each outer curve of each bend, and similarly, the puller wire 150 can extend to the sidewall of the delivery tube 110 on each outer curve of each bend. During the procedure, the delivery tube 110 and the puller wire 150 can be fed into the guide catheter 300 in a distal direction, first through bend A, then through bend B, and then through bend C. As the delivery tube 110 and puller wire 150 navigate along the bend, the proximal end 152 of the puller wire 150 may gradually approach the proximal end 132 of the intermediate hypotube 130 , causing the proximal end 152 of the puller wire 150 to move in the distal direction 14 relative to the delivery tube 110 .

[0054] Figures 4A to 4D The gradual movement of the proximal end 152 of the puller wire 150 as the delivery system 100 moves distally through bends A, B, and C is shown. Figure 4A The positioning of the proximal end 152 of the puller wire 150 is shown as the distal end 104 of the delivery system 100 approaches the bend A. Figure 4B Movement of the proximal end 152 of the puller wire 150 toward the intermediate hypotube 130 is shown as the distal end 104 of the delivery system 100 passes around bend A and approaches bend B. Figure 4C The proximal end of the puller wire 150 is shown moving further toward the intermediate hypotube 130 as the distal end 104 of the delivery system 100 passes around bend B and approaches bend C. Figure 4D The bead on the proximal end of the puller wire 150 is shown contacting the proximal end of the intermediate hypotube 130 as the distal end 104 of the delivery system 100 passes around the bend C and approaches the treatment site.

[0055] Joint participation Figure 3 and Figures 4A to 4D , as the delivery system 100 is moved distally to the treatment site, the proximal end 152 of the puller wire 150 is free to move in the proximal and distal directions relative to the delivery tube 110 and the intermediate hypotube 130. As shown, the bead 156 on the puller wire 150 can approach the proximal end of the hypotube 130 as the delivery system 100 is moved distally to the treatment site. Figures 4B to 4D The arrow shown indicates distal movement of the proximal end 152 of the puller wire 150 .

[0056] As the delivery system 100 moves distally, the gaps 190a, 190b, 190c, 190d between the bead 156 and the engagement surface 132 of the intermediate hypotube may gradually become smaller, as shown in FIG. Figures 4A to 4D As shown. Figure 4D , the bead 156 is shown engaged to the middle hypotube 130. In this position, the proximal end 152 of the puller wire 150 is inhibited from further movement in the distal direction 14, and the gap 190d spacing is collapsed, measuring essentially zero.

[0057] See also Figure 2 , the delivery system 100 may include a gap spacing 190 that can be measured between the distal surface of the bead 156 and the engagement surface 132 of the intermediate hypotube 130 when the delivery system 100 is extended in a substantially linear configuration from head to tail. The gap spacing 190 can be sized such that it is unlikely that the bead 156 will engage the hypotube 130 when the delivery system 100 is delivered to the treatment site. A larger gap spacing can allow for a greater travel distance of the proximal end 152 of the puller wire 150, thereby allowing for greater strain relief at the distal end of the puller wire, thereby reducing the likelihood of premature deployment of the treatment device. The maximum length of the gap spacing 190 can be limited by the ease of manipulation of the proximal end of the delivery system 100. For example, it may be difficult for a physician to manipulate a device having, for example, Figure 2 Thus, gap 190 can be sized to sufficiently relieve strain on the distal end of puller wire 150 to substantially reduce the likelihood of premature deployment of the therapeutic device and also facilitate easy manipulation of the delivery system during a treatment procedure.

[0058] Figure 5A and Figure 5B Manipulation of components at the proximal end of the delivery system 100 is shown to deploy a therapeutic device (eg, an implant). Figure 5C Shows the response to Figure 5A and Figure 5B Manipulation of the proximal end of the delivery system is shown to move the distal end 154 of the puller wire 150 to disengage the implant 200.

[0059] Figure 5AA sheath 170 is shown covering the proximal portion of the puller wire 150, including the proximal end 152 and the bead 156, the sheath 170 being attached to the intermediate hypotube 130 using a weld 178, the intermediate hypotube being attached to the delivery tube 110 using a distal weld 124, and the intermediate hypotube 130 being also secured to the delivery tube 100 at its proximal end using a proximal weld 122. The proximal weld 122 can be designed to be disconnected by the user during treatment, while the other welds 178, 124 attaching the intermediate hypotube 130 to the sheath 170 and delivery tube 110 can be designed to remain securely attached as the assembly is manipulated during treatment.

[0060] Figure 5B The sheath 170 is shown being pulled proximally, as indicated by the arrow. During treatment, a user may apply a force F sufficient to break the proximal weld 122 to separate the proximal end 112 of the delivery tube 110 from the intermediate hypotube 130. Alternatively, the proximal weld 128 may be broken by a twisting or bending force. After the weld 128 is broken, the sheath 170 may be moved proximally, as indicated by the arrow. The extendable section 138 of the intermediate hypotube 130 may be stretched, allowing the intermediate hypotube 130 to extend further beyond the proximal end 112 of the delivery tube 110. As the sheath 170 is moved proximally and the intermediate hypotube 130 is extended, the intermediate hypotube 130 may engage the bead 156 on the puller wire 150. As the sheath 170 is moved further proximally and the intermediate hypotube 130 is extended further, the bead 156 may be moved proximally, causing the length of the puller wire 150 to move proximally.

[0061] Figure 5C The distal end 154 of the puller wire 150 is shown extending through the loop wire 140. The arrow indicates that the distal end 154 of the puller wire 150 responds to the bead 156 on the puller wire 150 as shown in FIG. Figure 5B The bead 156 can be moved proximally a sufficient distance to allow the distal end 154 of the puller wire to pass proximally through the loop 140, thereby disengaging from the loop 140. Once the loop 140 is disengaged, the implant 100 can be deployed.

[0062] Figure 6 is a flow chart outlining exemplary method steps for designing and / or constructing a delivery system according to the present invention. Figure 7Flowchart outlining exemplary method steps for treating a patient using a delivery system according to the present invention. For each method 600, 700, the method steps can be implemented using the exemplary delivery systems and methods described herein or by methods known to those of ordinary skill in the art. The method steps are generally presented in the order in which they can be preferably performed. One of ordinary skill in the art will appreciate that certain steps can be performed simultaneously or in an alternative order.

[0063] See also Figure 6 In the method 600 outlined in FIG. 1 , a delivery tube, an intermediate hypotube, and a puller wire may be provided at step 610. The components provided may be the delivery tube 110, intermediate hypotube 130, and puller wire 150 described herein, variations thereof, or equivalent components known to those skilled in the art.

[0064] In step 620, an engagement lug can be formed near the proximal end of the puller wire, and the engagement lug can be sized to be larger than the lumen of the intermediate hypotube so that the engagement lug inhibits the proximal end of the puller wire from entering the lumen of the intermediate hypotube. The engagement lug can be the bead 156 on the puller wire 150 as described herein, variations thereof, or equivalent components known to those skilled in the art.

[0065] In step 630, the intermediate hypotube can be attached to the delivery tube such that the intermediate hypotube extends proximally from the delivery tube and is stretchable to extend further proximally from the proximal end of the delivery tube. The intermediate hypotube can be attached at a distal attachment location 124 as shown herein, otherwise attached as described herein, and / or by other means known to those skilled in the art. The intermediate hypotube can be stretchable along a portion 138 of its length as shown herein, otherwise stretchable as described herein, and / or by other means known to those skilled in the art.

[0066] In step 640, the puller wire can be positioned such that the puller wire extends through the lumens of the intermediate hypotube and the delivery tube, the puller wire extends proximally from the lumen of the intermediate hypotube, and the engagement lug is positioned in a proximal direction relative to the intermediate hypotube.

[0067] In step 650, the distal portion of the puller wire can be used to secure the intravascular therapeutic device at the distal end of the delivery tube. The intravascular therapeutic device can be an embolic coil 200 as shown herein, another therapeutic device as described herein, or a therapeutic device known to those skilled in the art. The distal portion of the puller wire can form part of an assembly that secures the therapeutic device during delivery and deploys the therapeutic device by proximal movement of the distal portion of the puller wire relative to the therapeutic device and / or the distal end of the delivery tube. The assembly used to deploy the therapeutic device can be a mechanical assembly such as shown and / or described herein, or an assembly known to those skilled in the art.

[0068] In step 660, the puller wire can be positioned such that the distal end of the puller wire is fixed relative to the distal end of the delivery tube, and the proximal end of the puller wire is slidably translatable relative to the proximal end of the delivery tube. The distal end of the puller wire can be fixed relative to the distal end of the delivery tube by means of a portion forming an assembly that secures the therapeutic device when it is delivered to the treatment site. The portion of the puller wire that forms the assembly to secure the therapeutic device can be the only point of attachment between the puller wires, such that the majority of the length of the puller wire has freedom of movement within the confines of the delivery tube, and the proximal end of the puller wire is free to move in both distal and proximal directions relative to the proximal end of the delivery tube.

[0069] In step 670, a sheath can be attached to the intermediate hypotube. The sheath can be positioned around the proximal end of the puller wire. The sheath can be sheath 170 as shown and described herein, variations thereof, or equivalent components known to those skilled in the art. The sheath can be attached to the intermediate hypotube at location 178 as shown herein, otherwise attached as described herein, and / or by other means known to those skilled in the art. The sheath can be configured to be grasped by the physician during treatment.

[0070] See also Figure 7 In the method 700 outlined in FIG, an intravascular delivery system having a delivery tube, an intermediate hypotube, and a puller wire may be selected in step 710. The intravascular delivery system may be the exemplary delivery system 100 described herein, variations thereof, or equivalent systems known to those skilled in the art.

[0071] In step 720, the proximal end of the puller wire can be surrounded by a sheath. The sheath can be sheath 170 as shown and described herein, variations thereof, or equivalent components known to those skilled in the art. With the help of the selected intravascular delivery system (step 710), the proximal end of the puller wire can be surrounded by a sheath in step 720, wherein the selected intravascular delivery system includes a sheath positioned around the proximal end of the puller wire. Alternatively, the sheath can be an auxiliary component selected to be separate from the intravascular delivery system, and the sheath can be positioned around the proximal end of the puller wire in step 720. In either case, the sheath, when attached, can be used to protect the proximal end of the puller wire from accidental manipulation and / or breakage.

[0072] In step 730, the delivery system may be extended through the patient's vasculature.

[0073] In step 740 , the proximal end of the puller wire may be allowed to move distally relative to the proximal end of the delivery tube as the delivery system is extended through the patient's vasculature.

[0074] In step 750, the proximal end of the puller wire may be restrained from entering the intermediate hypotube and delivery tube by engaging a bead on the puller wire to the hypotube.

[0075] In step 760, the sheath may be moved to extend the intermediate hypotube.

[0076] In step 770, the proximal end of the puller wire may be engaged and moved by extending the middle hypotube.

[0077] In step 780, the treatment device may be deployed by moving the proximal end of the puller wire proximally relative to the proximal end of the delivery tube.

[0078] 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 many variations and modifications of the intravascular delivery system, including: alternative components, alternative features for preventing the proximal end of the puller wire from becoming inaccessible due to distal movement of the puller wire, alternative features for protecting the proximal end of the puller wire from accidental premature manipulation, alternative means for extending the intermediate hypotube from the proximal end of the delivery tube, etc. 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. An intravascular delivery system comprising: a delivery tube sized to be delivered through a patient to a treatment site; an intermediate hypotube attached to the delivery tube and extending in a proximal direction from a proximal end of the delivery tube; and a puller wire extending through the lumen of the intermediate hypotube and through the lumen of the delivery tube, wherein the puller wire includes an engagement lug attached to the puller wire and positioned in the proximal direction relative to the proximal end of the hypotube, and wherein the engagement lug is movable in the distal direction relative to the proximal end of the intermediate hypotube, and wherein the engagement tab is sized to inhibit movement of the engagement tab into the lumen of the intermediate hypotube; and A stretch relief gap defines a length by which the engagement lug moves relative to the intermediate hypotube in the distal direction, the engagement lug not being engaged to the intermediate hypotube through the stretch relief gap.

2. The intravascular delivery system according to claim 1, further comprising: a sheath attached to the intermediate hypotube, Wherein a proximal portion of the puller wire including the engagement lug is positioned within the lumen of the sheath.

3. The intravascular delivery system according to claim 1, wherein the intravascular therapeutic device is positioned near the distal end of the intravascular delivery system, and The puller wire is movable to deploy the intravascular treatment device.

4. The intravascular delivery system according to claim 1, Wherein the distal end of the intermediate hypotube is positioned within the lumen of the delivery tube.

5. The intravascular delivery system according to claim 4, wherein the intermediate hypotube comprises an extendable section, and Wherein the extendable section is positioned within the lumen of the delivery tube.

6. A method comprising: providing a delivery tube sized to be delivered through a patient to reach a treatment site and including a lumen therethrough; providing an intermediate hypotube comprising a lumen therethrough; Provide pull wires; forming an engagement lug on the puller wire near a proximal end of the puller wire; attaching the intermediate hypotube to the delivery tube such that the intermediate hypotube extends in a proximal direction from a proximal end of the delivery tube and the intermediate hypotube is stretchable to extend further from the proximal end of the delivery tube; positioning the puller wire to extend through the lumen of the delivery tube and through the lumen of the intermediate hypotube; positioning the engagement lug in the proximal direction relative to the proximal end of the intermediate hypotube; sizing the engagement tab to inhibit movement of the engagement tab into the lumen of the intermediate hypotube; and A stretch relief gap is provided such that the stretch relief gap defines a length by which the engagement tab moves in a distal direction relative to the intermediate hypotube, the engagement tab not being engaged to the intermediate hypotube through the stretch relief gap.

7. The method according to claim 6, further comprising: The puller wire is positioned such that a distal end of the puller wire is fixed relative to the distal end of the delivery tube and the proximal end of the puller wire is slidably translatable relative to the proximal end of the delivery tube.

8. The method according to claim 6, further comprising: providing a sheath comprising a lumen therethrough; attaching the sheath to the intermediate hypotube; as well as The engagement tab is positioned within the lumen of the sheath.

9. The method according to claim 6, further comprising: The distal end of the puller wire is positioned to secure the intravascular treatment device adjacent the distal end of the delivery tube.

10. The method of claim 6, wherein the step of attaching the intermediate hypotube to the delivery tube further comprises: The distal end of the intermediate hypotube is attached within the lumen of the delivery tube.

11. The method according to claim 10, The step of providing the intermediate hypotube further comprises: providing a strain relief section on the intermediate hypotube, and Wherein the step of attaching the intermediate hypotube to the delivery tube further comprises: positioning the strain relief section of the intermediate hypotube within the lumen of the delivery tube, attaching a distal portion of the intermediate hypotube to the delivery tube, wherein the distal portion is located in the distal direction relative to the strain relief section, and A proximal portion of the intermediate hypotube is detachably attached to the delivery tube, wherein the proximal portion is located in the proximal direction relative to the strain relief section.

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