Friction pad and proximal protective device for intravascular implant

Abstract

An intravascular implant delivery system comprises an intravascular implant, an elongate tubular member, and a pusher member assembly. The intravascular implant is disposed within an inner member lumen of the elongate tubular member when in a radially collapsed delivery configuration, while the pusher member assembly is slidably disposed in the inner member lumen. The pusher member assembly comprises an elongate pusher member, a friction pad affixed relative to the pusher member, and a proximal protective device affixed relative to the pusher member. The friction pad is disposed within a central implant lumen of the intravascular implant. The pusher member is disposed within an axial pad lumen of the friction pad, and the proximal protective device is coaxially disposed between a proximal end of the intravascular implant and the inner member lumen.

Description

[0001] FRICTION PAD AND PROXIMAL PROTECTIVE DEVICE FOR INTRAVASCULAR IMPLANT

[0002] Field

[0003]

[0001] The present disclosure relates generally to minimally invasive assemblies used for delivering medial implants, and more particularly, to delivery assemblies for delivering intravascular implants, such as a tubular stent or flow diverter, to a targeted implantation site.

[0004] Background

[0005]

[0002] The use of intravascular implants, such as stents, stent grafts, flowdiverters, vaso-occlusive devices, vena cava filters, etc., has become an effective method for treating many types of vascular disease. In general, a suitable intravascular implant is inserted into the vascular system of the patient and navigated through the vasculature to a desired target site using a delivery system. Using currently available delivery systems, virtually any target site in the patient’s vascular system may be accessed, including the coronary, cerebral, and peripheral vasculature.

[0006]

[0003] In a typical intravascular medical device delivery procedure, a delivery catheter is percutaneously introduced into the vasculature of the patient over a guidewire and / or through a guide sheath. The open distal end of the delivery catheter is then navigated to a targeted implantation site using well-known techniques. An intravascular implant is delivered through a lumen of the delivery catheter in a collapsed or radially constrained (i.e., reduced diameter) delivery configuration. For example, a pusher member assembly having a pusher member (e.g., a core wire) on which the intravascular implant is temporarily affixed may be used to push the intravascular implant through the lumen of the delivery catheter. In conventional delivery systems, during manufacture, the intravascular implant may be pre-loaded in the radially collapsed configuration into the lumen of a tubular loading member (or introducer sheath) until the intravascular implant is located at the distal end of the tubular loading member. After the delivery catheter is navigated to the targeted implantation site, the distal end of the introducer sheath may be located adjacent the proximal end of the delivery catheter (e.g., at the proximal hub) and the pusher member may be distally displaced relative to the introducer sheath to transfer the intravascular implant from the lumen of the tubular loading member into the lumen of the delivery catheter while maintaining the radially collapsed configuration (i.e., preventing premature deployment of the intravascular implant).

[0007]

[0004] When the intravascular implant is located at the distal end of the delivery catheter, the intravascular implant can then be deployed out of the open distal end of the delivery catheter (e.g., by withdrawing the delivery catheter relative to the intravascular implant) and placed within an expanded (i.e., increased diameter) deployed configuration into engagement with the interior wall of the blood vessel. In one intravascular implant delivery method, the intravascular implant may be mounted over a balloon, which can then be inflated to radially expand the intravascular implant outward into engagement with the interior wall of the blood vessel. In another intravascular implant delivery method, the intravascular implant may be selfexpanding and loaded into the lumen of the catheter in an elastically collapsed state, such that the intravascular implant elastically expands once deployed out of the open distal end of the catheter without requiring assistance from a balloon. A radiopaque marker may be located at the distal tip of the delivery catheter, so that the implantation site of the intravascular implant can be estimated with the assistance of medical imaging technology (e.g., fluoroscopy).

[0008]

[0005] Oftentimes, once the intravascular implant is at least partially deployed from the delivery catheter, a physician may determine that the actual implantation site of the intravascular implant may be located away from the targeted implantation site of the intravascular implant, and thus, clinically undesirable. The actual implantation site of the intravascular implant may be clinically undesirable for a number of reasons. For example, if the intravascular implant is a stent for bridging the neck of an aneurysm or diverting flow from an aneurysm or a blood vessel, an accurate implantation of the stent at the targeted implantation site is needed. If the stent fails to cover the entire aneurysm, or the stent is located on a bend that may cause a thrombosis or stroke, or the stent covers another vessel, the intravascular stent may need to be repositioned. In the case of a self-expanding intravascular implant, if the intravascular implant has not been deployed from the delivery catheter past a point-of-no-return (i.e., the point at which the intravascular implant cannot be retracted back into the delivery catheter), the intravascular stent may be resheathed within the delivery catheter and repositioned, such that the intravascular implant can be redeployed at the targeted implantation site. In some embodiments, a friction pad can be located between the pusher member and the proximal end of the intravascular implant to facilitate distally pushing the intravascular implant through the lumens of the introducer sheath and delivery catheter, as well as resheathing the intravascular implant within the lumen of the delivery catheter, as described in U.S. Provisional Application Ser. No. 63 / 397,679, which is expressly incorporated herein by reference.

[0009]

[0006] Referring to Figs. 1-2, one embodiment of a delivery system 1 for delivering an intravascular implant 2 at a targeted implantation site 3 within a blood vessel 4 (shown in Figs. 3A-3B and 4A-4B). The delivery system 1 comprises a delivery catheter 5 having an inner lumen 6, and a pusher member assembly 7 for carrying and axially translating the intravascular implant 2 within the inner lumen 6 of the delivery catheter 5. The delivery system 1 may optionally comprise a tubular loading member (e.g., an introducer sheath) (not shown) for initially loading the pusher member assembly 7, along with the intravascular implant 2, into the inner lumen 6 of the delivery catheter 5.

[0010]

[0007] The pusher member assembly 7 comprises a pusher member 8 and a proximal bumper 9a and a distal bumper 9b affixed to the pusher member 8, thereby forming an annular space 10 between the bumpers 9a, 9b. The proximal bumper 9a may serve as a radiopaque marker to indicate the proximal end of the intravascular implant 2, so that full deployment of the intravascular implant 2 from the delivery catheter s can be confirmed. The distal bumper 9b may serve as a radiopaque marker that indicates the point-of-no-return as the intravascular implant 2 is being deployed from the delivery catheter 5, after which the intravascular implant 2 may no longer be resheathed into the delivery catheter 5. Other radiopaque markers (not shown) may be located on the distal end of the delivery catheter 5 and other locations along the pusher member 8. The pusher member assembly 7 may further comprise a protective device 11 located at the distal end of the intravascular implant 2 for protecting the distal end of the intravascular implant 2 when being loaded into the proximal end of the introducer sheath, and distally transferred into, advanced through, and deployed out of, the delivery catheter 5, and / or preventing the deposition of foreign matter within the introducer sheath and delivery catheter. The pusher member assembly 7 further comprises an elastomeric friction pad 12 disposed on the pusher member 8 within the annular space 10 between the bumpers 9a, 9b. The proximal and distal bumpers 9a, 9b serve to retain the friction pad 12 therebetween. The pusher member assembly 7 further comprises an atraumatic distal portion 13 affixed to the distal end of the pusher member 8.

[0008] The proximal end of the intravascular implant 2 is disposed within the inner lumen 6 of the delivery catheter 5 between the outer surface 14 of the friction pad 12 and the inner surface 15 of the delivery catheter 5. The friction pad 12 is disposed within the inner lumen 6 of the delivery catheter 5 in a compressed state, such that friction pad 12 imparts a radially outward force 16 against an inner surface 17 at the proximal end of the intravascular implant 2, while the inner lumen 6 of the delivery catheter 5 imparts a radially inward force 18 against an outer surface 19 at the proximal end of the intravascular implant 2, as best illustrated in Fig. 2. In this manner, the proximal end of the intravascular implant 2 is frictionally engaged with the pusher member assembly 7, such that the intravascular implant 2 moves in unison with the pusher member assembly 7 as the pusher member assembly 7 and delivery catheter 5 are axially translated relative to each other (e.g., by translating the delivery catheter 5 in the proximal direction 20 while holding the pusher member assembly 7 in place) to deploy the intravascular implant 2 out of a distal port 21 of the delivery catheter 5 and into the blood vessel 4, as illustrated in Figs. 3A and 3B.

[0011]

[0009] Because the tensile strength of the intravascular implant 2, alone, is very low, the friction pad 12 not only facilitates deployment of the intravascular implant 2, it serves to facilitate resheathing of the intravascular implant 2 within the inner lumen 6 of the delivery catheter 5 (e.g., by translating the delivery catheter 5 in the distal direction 22 while holding the pusher member assembly 7 in place), as illustrated in Figs. 4A and 4B. As long as the intravascular implant 2 has not been deployed from the delivery catheter 5 past the point-of-no-return (i.e., as long as distal bumper 9b remains in the inner lumen 6 of the delivery catheter 5, indicating that the friction pad 12, which will tend to expand outside of the constraints of the delivery catheter 5, is fully within the inner lumen 6 of the delivery catheter 5), the intravascular implant 2, facilitated by the friction pad 12, may be resheathed back into the delivery catheter 5.

[0010] However, as illustrated in Fig. 5, an elastomeric friction pad 12 composed of a low durometer material has a relatively low columnar strength, such that it is prone to radial outward bulging (shown in phantom) in the radial direction 23 in response to an axially compressive force 24, e.g., caused by increased resistance to the translation of the intravascular implant 2 within the inner lumen 6 of the delivery catheter 5 during deployment and / or resheathing of the intravascular implant 2. This radial outward bulging of the friction pad 12 can prohibitively increase track / resheath force of the intravascular implant 2, while also increasing the potential for particle generation at the ends of the intravascular implant 2. In some cases, the increased track / resheath force may even cause the friction pad 12 to prolapse over the proximal bumper 9a or distal bumper 9b, thereby rendering the delivery system 1 unusable.

[0012]

[0011] Furthermore, some intravascular implant delivery systems may utilize protective covers for protecting the distal ends of the intravascular implants, such as those disclosed in U.S. Patent Publication No. 2022 / 0280277, the inventors have discovered that there may instances where it is desirable to protect the proximal ends of intravascular implants. As one example, during resheathing, the intravascular implant may be damaged, foreign matter may be created, or the delivery catheter may be damaged when the proximal end of the intravascular implant contacts the distal end of the delivery catheter. As another example, it may be desirable to proximally (or reverse) load the intravascular implant into the introducer sheath (i.e., the proximal end of the intravascular implant is loaded into the distal end of the introducer sheath), thereby significantly decreasing the distance that the intravascular implant needs to travel through the lumen to locate it at the distal end of the introducer sheath). However, during manufacture, the intravascular implant may be damaged, foreign matter may be created, or the introducer sheath may be damaged when the proximal end of the intravascular implant contacts the distal end of the introducer sheath or pushed through the lumen of the introducer sheath, especially since the inner lumen of the introducer sheath is not lubricated, e.g., by saline.

[0013]

[0012] There, thus, remains an ongoing need to minimize the track / resheath force of an intravascular implant through a delivery catheter, while also protecting the intravascular device during proximal loading into an introducer sheath for subsequent transfer to a delivery sheath and during resheathing of the intravascular device into the delivery catheter.

[0014] Summary

[0015]

[0013] In accordance with one aspect of the present inventions, an intravascular implant delivery system comprises an intravascular implant (e.g., a stent, a stent graft, a flow-diverter, a vaso-occlusive device, a vena cava filter, etc.) having alternately a radially collapsed delivery configuration and a radially expanded deployed configuration, and an elongate tubular member having an inner member lumen in which the intravascular implant is disposed when in the radially collapsed delivery configuration.

[0014] The intravascular implant delivery system further comprises a pusher member assembly slidably disposed in the inner member lumen. The pusher member assembly comprises an elongate pusher member (e.g. a delivery wire), a friction pad affixed relative to the pusher member and disposed within a central implant lumen of the intravascular implant, and a proximal protective device affixed relative to the pusher member and coaxially disposed between a proximal end of the intravascular implant and the inner member lumen. The pusher member is disposed within an axial pad lumen of the friction pad. In one embodiment, the friction pad and the proximal protective device form a monolithic structure. In another embodiment, the proximal protective device is self-expanding. In still another embodiment, the pusher member assembly further comprises a proximal bumper and a distal bumper affixed to the pusher member, thereby forming an annular space therebetween in which the friction pad and proximal protective device are disposed. In an optional embodiment, the pusher member assembly further comprises a distal protective device affixed relative to the pusher member and coaxially disposed between a distal end of the intravascular implant and the inner member lumen. The friction pad may have a suitable durometer, e.g., greater than 35D, and preferably, in the range of 70D-85D. The friction pad may have a suitable shape, e.g., cylindrical, but may have other alternative shapes.

[0016]

[0015] In one embodiment, the friction pad is configured for frictionally engaging the intravascular implant while the proximal protective device is configured for slidably bearing against the inner member lumen as the pusher member assembly slides in the inner member lumen. In one example of this embodiment, the delivery sheath is an introducer sheath having a distal end configured for being axially aligned with a proximal end of a delivery catheter having an inner catheter lumen. In this example, the friction pad is configured for frictionally engaging the intravascular implant while proximal protective device is configured for slidably bearing against the inner member lumen and the inner catheter lumen when the pusher member assembly slides in the inner member lumen and inner catheter lumen, such that the intravascular implant may be transferred from the inner member lumen to the inner catheter lumen while maintained in the radially collapsed delivery configuration. In another example of this embodiment, the delivery sheath is a delivery catheter configured for being navigated through a vasculature to a desired target site of a patient, and the inner member lumen is an inner catheter lumen. In this example, the friction pad is configured for frictionally engaging the intravascular implant while the proximal protective device is configured for slidably bearing against the inner member lumen when the pusher member assembly slides in the inner member lumen, such that the intravascular implant may be deployed from the inner catheter lumen into the radially expanded deployed configuration at the target tissue site. Optionally, the friction pad may be configured for frictionally engaging the intravascular implant while the proximal protective device may be configured for slidably bearing against the inner member lumen when the pusher member assembly slides in the inner member lumen, such that the intravascular implant may be resheathed back into the radially collapsed delivery configuration within the inner catheter lumen.

[0017]

[0016] In another embodiment, the friction pad and the proximal protective device axially overlap, such that the proximal end of the intravascular implant is sandwiched between the friction pad and the proximal protective device. For example, the friction pad may have a distal section having a first profile and a proximal section having a second profile less than the first profile, thereby forming an enlarged space between the proximal section of the friction pad and the proximal protective device, such that a portion of the proximal end distal to a proximal edge of the intravascular implant is sandwiched between the distal section of the friction pad and the proximal protective device, while the proximal edge of the intravascular implant is disposed within the enlarged space.

[0018]

[0017] In still another embodiment, the proximal protective device is configured for alternately being in a radially collapsed configuration when radially constrained by the inner member lumen, thereby engaging the proximal end of the intravascular implant, and for being in a radially expanded configuration when not radially constrained by the inner member lumen, thereby releasing the proximal end of the intravascular implant. In this embodiment, the proximal protective element may comprise a plurality of radially collapsible / expandable elements configured for radially collapsing when the proximal protective device is in the radially collapsed configuration, and for radially expanding when the proximal protective device is in the radially expanded configuration. The proximal protective element may further comprise a base proximal to the friction pad. In this case, the base may have a profile greater than a profile of the friction pad, and the base may have a ledge forming a distal face from which the plurality of radially collapsible / expandable elements extends. The plurality of radially collapsible / expandable elements may comprise a plurality of proximally-cantilevered arms configured for cantilevering outward when the proximal protective device is in the radially expanded configuration, and for cantilevering inward when the proximal protective device is in the radially collapsed configuration. The plurality of proximally- cantilevered arms may be configured for cantilevering inward in a non-overlapping fashion when the proximal protective device is in the radially collapsed configuration. The plurality of proximally-cantilevered arms may extend over the friction pad, thereby sandwiching the proximal end of the intravascular implant between the friction pad and the plurality of proximally-cantilevered arms. A center of each of the plurality of proximally-cantilevered arms may optionally be angled radially outward. A suitable number of proximally-cantilevered arms (e.g., four) may be provided and / or the plurality of proximally-cantilevered arms may be equally distributed around a circumference of the friction pad.

[0019]

[0018] In accordance with another aspect of the present inventions, a pusher member assembly configured for translating an intravascular implant having a radially collapsed delivery configuration when radially constrained within an inner member lumen of an elongate tubular member and a radially expanded deployed configuration when not radially constrained within the inner member lumen is provided.

[0020]

[0019] The pusher member assembly comprises an elongate pusher member (e.g., a delivery wire), a friction pad affixed relative to the pusher member and being configured for being disposed within a central implant lumen of the intravascular implant when the intravascular implant is in the radially collapsed delivery configuration, and a proximal protective device affixed relative to the pusher member and being configured for being coaxially disposed between a proximal end of the intravascular implant and the inner member lumen when the intravascular implant is in the radially collapsed delivery configuration. The pusher member is disposed within an axial pad lumen of the friction pad. In one embodiment, the friction pad and the proximal protective device form a monolithic structure. In another embodiment, the proximal protective device is self-expanding. In still another embodiment, the pusher member assembly further comprises a proximal bumper and a distal bumper affixed to the pusher member, thereby forming an annular space therebetween in which the friction pad and proximal protective device are disposed. In an optional embodiment, the pusher member assembly further comprises a distal protective device affixed relative to the pusher member and being configured for being coaxially disposed between a distal end of the intravascular implant and the inner member lumen. The friction pad may have a suitable durometer, e.g., greater than 35D, and preferably, in the range of 70D-85D. The friction pad may have a suitable shape, e.g., cylindrical, but may have other alternative shapes.

[0021]

[0020] In one embodiment, the friction pad is configured for frictionally engaging the intravascular implant when the intravascular implant is in the radially collapsed delivery configuration while the proximal protective device is configured for slidably bearing against the inner member lumen as the pusher member assembly slides in the inner member lumen when the proximal protective device is between the proximal end of the intravascular implant and the inner member lumen.

[0022]

[0021] In another embodiment, the friction pad and the proximal protective device axially overlap, such that the proximal end of the intravascular implant is configured for being sandwiched between the friction pad and the proximal protective device when the intravascular implant is in the radially collapsed delivery configuration. For example, the friction pad may have a distal section having a first profile and a proximal section having a second profile less than the first profile, thereby forming an enlarged space between the proximal section of the friction pad and the proximal protective device, such that a portion of the proximal end distal to a proximal edge of the intravascular implant is configured for being sandwiched between the distal section of the friction pad and the proximal protective device when the intravascular implant is in the radially collapsed delivery configuration, while the proximal edge of the intravascular implant is disposed within the enlarged space.

[0023]

[0022] In still another embodiment, the proximal protective device is configured for alternately being in a radially collapsed configuration when radially constrained by the inner member lumen, thereby engaging the proximal end of the intravascular implant, and for being in a radially expanded configuration when not radially constrained by the inner member lumen, thereby releasing the proximal end of the intravascular implant. In this embodiment, the proximal protective element may comprise a plurality of radially collapsible / expandable elements configured for radially collapsing when the proximal protective device is in the radially collapsed configuration, and for radially expanding when the proximal protective device is in the radially expanded configuration. The proximal protective element may further comprise a base proximal to the friction pad. In this case, the base may have a profile greater than a profile of the friction pad, and the base may have a ledge forming a distal face from which the plurality of radially collapsible / expandable elements extends. The plurality of radially collapsible / expandable elements may comprise a plurality of proximally-cantilevered arms configured for cantilevering outward when the proximal protective device is in the radially expanded configuration, and for cantilevering inward when the proximal protective device is in the radially collapsed configuration. The plurality of proximally- cantilevered arms may be configured for cantilevering inward in a non-overlapping fashion when the proximal protective device is in the radially collapsed configuration. The plurality of proximally-cantilevered arms may extend over the friction pad, such that the proximal end of the intravascular implant is configured for being sandwiched between the friction pad and the proximal protective device when the intravascular implant is in the radially collapsed delivery configuration. A center of each of the plurality of proximally-cantilevered arms may optionally be angled radially outward. A suitable number of proximally-cantilevered arms (e.g., four) may be provided and / or the plurality of proximally-cantilevered arms may be equally distributed around a circumference of the friction pad.

[0024]

[0023] In accordance with still another aspect of the present inventions, a monolithic medical device for protecting a proximal end of an intravascular implant having a central implant lumen is provided.

[0025]

[0024] The monolithic medical device comprises a friction pad having a pad body sized to be received in the central implant lumen and an axial pad lumen configured for receiving a pusher member.

[0026]

[0025] The monolithic medical device further comprises a base proximal to the pad body. The base has a profile greater than a profile of the pad body, such that a ledge having a distal face is formed between the base and the friction pad.

[0027]

[0026] The monolithic medical device further comprises a plurality of arms distally extending from the distal face, such that, when radially constrained, are configured for being cantilevered toward the friction pad, such that friction pad and plurality of arms axially overlap to frictionally engage the proximal end of the intravascular implant, and when radially unconstrained, being configured for being cantilevered away from the friction pad to release the proximal end of the intravascular implant.

[0028]

[0027] In one embodiment, the pad body has a distal section having a first profile and a proximal section having a second profile less than the first profile, thereby forming an enlarged space between the proximal section of the pad body and the plurality of arms, such that a portion of the proximal end distal to a proximal edge of the intravascular implant is configured for being sandwiched between the distal section of the friction pad and the proximal protective device, while the proximal edge of the intravascular implant is configured for being disposed within the enlarged space. In another embodiment, the plurality arms have a flattened profile. In still another embodiment, a center of each of the plurality of arms is angled radially outward. A suitable number of proximally-cantilevered arms (e.g., four) may be provided and / or the plurality of proximally-cantilevered arms may be equally distributed around a circumference of the friction pad. The friction pad, base, and plurality of arms may have a suitable durometer, e.g., greater than 35D, and preferably, in the range of 70D- 85D. The friction pad and base may have a suitable shape, e.g., cylindrical, but may have other alternative shapes.

[0029]

[0028] In accordance with yet another aspect of the present inventions, a method of manufacturing an intravascular implant loading assembly using an elongate pusher member (e.g., a delivery wire), a friction pad, a proximal protective device configured for alternately having a radially expanded configuration and a radially collapsed configuration, an introducer sheath, and an intravascular implant (e.g., a stent, a stent graft, a flow-diverter, a vaso-occlusive device, a vena cava filter, etc.) configured for alternately having a radially expanded configuration and a radially collapsed configuration is provided. The friction pad may have a suitable durometer, e.g., greater than 35D, and preferably, in the range of 70D-85D. The friction pad may have a suitable shape, e.g., cylindrical, but may have other alternative shapes.

[0030]

[0029] The method comprises threading an elongate pusher member through an axial lumen of the friction pad and an axial lumen of the proximal protective device, and axially affixing the friction pad and the proximal protective device to the pusher member to form a pusher member assembly. In one method, axially affixing the friction pad to the pusher member comprises affixing a proximal bumper to the pusher member proximal to the friction pad, and affixing a distal bumper to the pusher member distal to the friction pad.

[0031]

[0030] The method further comprises disposing the friction pad within a central lumen at the proximal end of an intravascular implant while the intravascular implant is in the radially expanded configuration, and disposing the proximal protective device over the proximal end of the intravascular implant while the proximal protective device is in the radially expanded configuration, thereby forming a concentric arrangement with the intravascular implant and the pusher member assembly. In one method, the friction pad and the proximal protective device axially overlap, such that the proximal end of the intravascular implant is sandwiched between, and thus frictionally engaged by, the friction pad and the proximal protective device in the concentric arrangement. In one method, the proximal protective device is self-expanding. In another method, the friction pad and the proximal protective device form a monolithic structure. In still another method, the proximal protective device may comprise a base proximal to the friction pad, and the base has a profile greater than a profile of the friction pad, such that a ledge having a distal face is formed between the base and the friction pad.

[0032]

[0031] The method further comprises loading the intravascular implant into an inner sheath lumen of the introducer sheath, wherein the inner sheath lumen radially constrains the proximal protective device and intravascular implant into the respective radially collapsed configurations. In one method, the intravascular implant is proximally loaded into the inner sheath lumen, such that the proximal protective device slidably bears against the inner sheath lumen.

[0033]

[0032] An optional method further comprises threading the elongate pusher member through an axial lumen of a distal protective device having a radially expanded configuration and a radially collapsed configuration, axially affixing the distal protective device to the elongate pusher member, and disposing the distal protective device over the distal end of the intravascular implant while the distal protective device is in the radially expanded configuration, thereby adding the distal protective device to the concentric arrangement. In one method, the proximal protective device comprises a plurality of arms configured for being cantilevered toward the friction pad when the intravascular implant is loaded into the inner sheath lumen, thereby frictionally engaging the proximal end of the intravascular implant against the friction pad.

[0034]

[0033] Other and further aspects and features of embodiments of the disclosed inventions will become apparent from the ensuing detailed description in view of the accompanying figures.

[0035] Brief Description of the Drawings

[0036]

[0034] The drawings illustrate the design and utility of preferred embodiments of the present invention, in which similar elements are referred to by common reference numerals. It should be noted that the figures are not drawn to scale and that elements of similar structures or functions are represented by like reference numerals throughout the figures. It should also be noted that the figures are only intended to facilitate the description of the embodiments. They are not intended as an exhaustive description of the invention or as a limitation on the scope of the invention, which is defined only by the appended claims and their equivalents. In addition, an illustrated embodiment of the disclosed inventions needs not have all the aspects or advantages shown. An aspect or an advantage described in conjunction with a particular embodiment of the disclosed inventions is not necessarily limited to that embodiment and can be practiced in any other embodiments even if not so illustrated. In order to better appreciate how the above-recited and the other advantages and objects of the present inventions are obtained, a more particular description of the present inventions briefly described above will be rendered by reference to specific embodiments thereof, which are illustrated in the accompanying drawings. Understanding that these drawings depict only typical embodiments of the invention and are not therefore to be considered limiting of its scope, the invention will be described and explained with additional specificity and detail through the use of the accompanying drawings in which:

[0037]

[0035] Fig. 1 is a longitudinal-sectional view of a prior art delivery system for delivering an intravascular implant into a patient.

[0038]

[0036] Fig. 2 is a cross-sectional view of the delivery system of Fig. 1 , taken along the line 2-2

[0039]

[0037] Figs. 3A-3B are plan views illustrating a prior art method using the delivery system of Fig. 1 to deploy an intravascular implant within the vasculature of a patient.

[0040]

[0038] Figs. 4A-4B are plan views illustrating a prior art method using the delivery system of Fig. 1 to resheath the intravascular implant.

[0041]

[0039] Fig. 5 is a perspective view illustrating an elastomeric friction pad of the prior art delivery system, particularly showing the friction pad radially bulging in response to a compressive force.

[0042]

[0040] Fig. 6 is a plan view of one embodiment of an intravascular implant delivery system constructed in accordance with the present inventions.

[0043]

[0041] Fig. 7A is a plan view of the distal end of an intravascular implant loading assembly of the intravascular implant delivery system of Fig. 6.

[0044]

[0042] Fig. 7B is a plan view of distal end of a delivery catheter loaded with the pusher member assembly and the intravascular implant.

[0045]

[0043] Fig. 7C is a cut-away plan view of the distal end of the pusher member assembly loaded into the delivery catheter of Fig. 7B.

[0044] Fig. 7D is a cut-away perspective view of the pusher member assembly taken along the section 7D of the pusher member assembly of Fig. 7C.

[0046]

[0045] Fig. 7E is a plan view of the intravascular implant carried by section 7E of the loaded delivery catheter of Fig. 7C.

[0047]

[0046] Fig. 7F is a close-up plan view of a portion of the loaded delivery catheter of Fig. 7B, taken along the line 7F-7F.

[0048]

[0047] Fig. 7G is a close-up plan view of a portion of the loaded delivery catheter of Fig. 7B, particularly showing the intravascular implant while deployed.

[0049]

[0048] Fig. 7H is a cross-sectional view of the loaded delivery catheter of Fig. 7F, taken along the line 7H-7H.

[0050]

[0049] Fig. 71 is a cross-sectional view of the loaded delivery catheter of Fig. 7G, taken along the line 71-71.

[0051]

[0050] Fig. 8 is a proximal perspective view of one embodiment of a monolithic retaining structure forming a friction pad and a proximal protective device of the pusher member assembly of Fig. 7D, particularly showing the proximal protective device in a radially collapsed configuration.

[0052]

[0051] Fig. 9 is a proximal perspective view of the monolithic retaining structure of Fig. 8, particularly showing the proximal protective device in a radially expanded configuration.

[0053]

[0052] Fig. 10 is a distal perspective view of the monolithic retaining structure of Fig. 8, particularly showing the proximal protective device in the radially expanded configuration.

[0054]

[0053] Fig. 11 is a side view of the monolithic retaining structure of Fig. 8, particularly showing the proximal protective device in the radially expanded configuration.

[0055]

[0054] Fig. 12 is a distal axial view of the monolithic retaining structure of Fig. 8, particularly showing the proximal protective device in the radially expanded configuration.

[0056]

[0055] Fig. 13 is a longitudinal-sectional view of the monolithic retaining structure of Fig. 8, particularly showing an intravascular implant frictionally engaged by the friction pad and proximal protective device.

[0057]

[0056] Fig. 14 is a longitudinal-sectional view of the monolithic retaining structure of Fig. 8, particularly showing an intravascular implant released by the friction pad and proximal protective device.

[0057] Fig. 15 is a distal perspective view of another embodiment of a monolithic retaining structure forming a friction pad and a proximal protective device of the pusher member assembly of Fig. 7D, particularly showing the proximal protective device in a radially expanded configuration.

[0058]

[0058] Fig. 16 is a side of the monolithic retaining structure of Fig. 15, particularly showing the proximal protective device in the radially expanded configuration.

[0059]

[0059] Fig. 17 is a distal axial view of the monolithic retaining structure of Fig. 15, particularly showing the proximal protective device in the radially expanded configuration.

[0060]

[0060] Fig. 18 is a proximal perspective view of still another embodiment of a monolithic retaining structure forming a friction pad and a proximal protective device of the pusher member assembly of Fig. 7D, particularly showing the proximal protective device in a radially collapsed configuration.

[0061]

[0061] Fig. 19 is a proximal perspective view of the monolithic retaining structure of Fig. 18, particularly showing the proximal protective device in a radially expanded configuration.

[0062]

[0062] Fig. 20 is a distal perspective view of the monolithic retaining structure of Fig. 18, particularly showing the proximal protective device in the radially expanded configuration.

[0063]

[0063] Fig. 21 is a side view of the monolithic retaining structure of Fig. 18, particularly showing the proximal protective device in the radially expanded configuration.

[0064]

[0064] Fig. 22 is a distal axial view of the monolithic retaining structure of Fig. 18, particularly showing the proximal protective device in the radially expanded configuration.

[0065]

[0065] Fig. 23 is a longitudinal-sectional view of the monolithic retaining structure of Fig. 18, particularly showing an intravascular implant frictionally engaged by the friction pad and proximal protective device.

[0066]

[0066] Fig. 24 is a longitudinal-sectional view of the monolithic retaining structure of Fig. 18, particularly showing an intravascular implant released by the friction pad and proximal protective device.

[0067]

[0067] Fig. 25 is a proximal perspective view of yet another embodiment of a monolithic retaining structure forming a friction pad and a proximal protective device of the pusher member assembly of Fig. 7D, particularly showing the proximal protective device in a radially collapsed configuration.

[0068]

[0068] Fig. 26 is a proximal perspective view of the monolithic retaining structure of Fig. 25, particularly showing the proximal protective device in a radially expanded configuration.

[0069]

[0069] Fig. 27 is a side view of yet another embodiment of a monolithic retaining structure forming a friction pad and a proximal protective device of the pusher member assembly of Fig. 7D, particularly showing the proximal protective device in a radially collapsed configuration.

[0070]

[0070] Fig. 28 is a side view of the monolithic retaining structure of Fig. 27, particularly showing the proximal protective device in a radially expanded configuration.

[0071]

[0071] Fig. 29 is a distal axial view of the monolithic retaining structure of Fig. 27, particularly showing the proximal protective device in the radially expanded configuration; and

[0072]

[0072] Fig. 30 is a flow diagram illustrating one method of fabricating the intravascular implant loading assembly of Fig. 7A.

[0073] Detailed Description of the Illustrated Embodiments

[0074]

[0073] Referring to Figs. 6 and 7A-7I, one embodiment of an implant delivery system 100 constructed in accordance with the present inventions will be described. The implant delivery system 100 generally comprises an intravascular implant 102 (shown best in Figs. 7A-7B and 7E); a delivery catheter 104 for delivering the intravascular implant 102 to a target site in the vasculature of the patient, and if necessary, resheathing the intravascular implant 102 within the delivery catheter

[0075] 104; a tubular loading member in the form of an introducer sheath 106 for initially transferring the intravascular implant 102 to the delivery catheter 104; and a pusher member assembly 108 for facilitating distal advancement of the intravascular implant 102 through the introducer sheath 106 and delivery catheter 104.

[0076]

[0074] In the illustrated embodiment, the intravascular implant 102, introducer sheath 106, and pusher member assembly 108 are initially provided in a coaxial arrangement as an intravascular implant loading assembly to a physician. After the delivery catheter 104 has been introduced into the vasculature of the patient, the intravascular implant 102 may be transferred from the introducer sheath 106 to the delivery catheter 104, after which, the intravascular implant 102, delivery catheter 104, and pusher member assembly 108 will be in a coaxial arrangement while the delivery catheter 104 is in the vasculature of the patient.

[0077]

[0075] The intravascular implant 102 takes the form of, e.g., a stent, a stent graft, flow-diverter, vaso-occlusive device, vena cava filter, etc., for treating an anomaly within the vasculature of a patient, such as an occlusion in a blood vessel, in a blood vessel adjacent to an aneurysm neck, a bifurcated blood vessel, or the like at a target site. The intravascular implant 102 may have a suitable length, e.g., 1cm- 15cm. As illustrated in Figs. 7F and 7H, the intravascular implant 102, in its radially collapsed delivery configuration, may be disposed within the delivery catheter 104 (or alternatively within the introducer sheath 106) in a coaxial arrangement with the distal portion of the pusher member assembly 108. In contrast, as illustrated in Figs. 7G and 71, the intravascular implant 102, in its expanded deployed configuration, is no longer disposed within the delivery catheter 104, but may still be in a coaxial arrangement with the distal portion of the pusher member assembly 108.

[0078]

[0076] As best illustrated in Fig. 7E, the intravascular implant 102 generally comprises a tubular body 110 having a proximal end 112 and a distal end 114, and a central lumen 116 axially extending entirely through the tubular body 110. The tubular body 110 further has a proximal edge 119 (in this case, a proximal annular edge) and a distal edge 121 (in this case, a distal annular edge). The tubular body 110 is composed of a resilient material, such that the intravascular implant 102 assumes a radially collapsed delivery configuration when radially constrained within the delivery catheter 104 or the introducer sheath 106 (i.e., when the intravascular implant 102 is axially translated within the introducer sheath 106 during transfer of the intravascular implant 102 from the introducer sheath 106 to the delivery catheter 104 or when the intravascular implant 102 is being axially translated within the delivery catheter 104 prior to deployment from the delivery catheter 104 or after resheathing within the delivery catheter 104), and automatically assumes a radially expanded deployed configuration when not radially constrained within the delivery catheter 104 (i.e., when the intravascular implant 102 is deployed from the delivery catheter 104).

[0079]

[0077] The tubular body 110 may be composed of a variety of biocompatible materials, such as, e.g., stainless steel, elgiloy, nickel, titanium, nitinol, shape memory polymers, or combinations thereof, and may be constructed using well- known techniques, such as by etching or cutting a pattern from a tube or sheet of stent material, or by weaving / braiding one or more wires or ribbons into a desired shape and pattern. The intravascular implant 102 may include further components that are welded, bonded or otherwise engaged to one another, and may optionally include a non-porous, non-permeable biocompatible material, cover or the like. The intravascular implant 102 may optionally comprise bioactive or therapeutic agents carried by, or coated on the inner surface or outer surface of the, tubular body 110.

[0080]

[0078] As best shown in Figs. 6 and 7B, the delivery catheter 104 may, e.g., have a length about 50cm-300cm, and typically about 60cm-200cm. The delivery catheter 104 is configured for accessing a body lumen, such as a blood vessel, for a desired treatment in at the target site in the vasculature of a patient. For example, the target site may be within a small diameter blood vessel having a 2-5mm lumen diameter and accessible by way of a tortuous vessel path, which may involve multiple vessels turns and multiple vessel branches. In such cases, the delivery catheter 104 has a small suitable diameter and flexible construction. The delivery catheter 104 may be used in an “over-the-wire” configuration, wherein the delivery catheter 104 is introduced into the vasculature of the patient over a guidewire (not shown) that has been previously introduced, and the delivery catheter 104 extends over the entire length of the guidewire (not shown). Alternatively, the implant delivery system 100 may be used in a “rapid-exchange” configuration, where a guidewire (not shown) extends through only a distal portion of the delivery catheter 104 from a guidewire port (not shown).

[0081]

[0079] As best illustrated in Figs. 6 and 7B, the delivery catheter 104 comprises an elongate tubular body 120 having a proximal portion 122 and a distal portion 124, and an inner lumen 126 axially extending entirely through the tubular body 120. The inner lumen 126 terminates at a distal port 128 at the end of the distal portion 124 of the tubular body 120. The proximal portion 122 of the tubular body 120 remains outside of the patient and accessible to the operator, while the distal portion 124 of the tubular body 120 is sized and dimensioned to reach remote locations of a vasculature to deliver the intravascular implant 102 to the target site in the vasculature of the patient. The inner lumen 126 is sized to accommodate axial translation of the radially collapsed intravascular implant 102 and the pusher member assembly 108.

[0080] As best shown in Fig. 6, the delivery catheter 104 comprises a proximal adapter 130 affixed to the proximal portion 122 of the tubular body 120. The proximal adapter 130 comprises a central bore 132 (shown in phantom) in communication with the inner lumen 126 of the tubular body 120. The central bore 132 terminates in a proximal port 134 for allowing loading of the intravascular implant 102 (and in this case, transfer of the intravascular implant 102 from the introducer sheath 106) into the inner lumen 126 of the delivery catheter 104. The proximal adapter 130 may be configured for being coupled to a conventional rotary hemostasis valve (RHV) (not shown) via a connector 136 (e.g., a Luer connector) for preventing backflow of blood out of the delivery catheter 104 while allowing the introduction of fluids into the delivery catheter 104 and introducer sheath 106 in order to hydrate the pusher member assembly 108 and the intravascular implant 102 during translation within the inner lumen 126 of the delivery catheter 104. The delivery catheter 104 further comprises an atraumatic distal tip 138 affixed to the distal end of the tubular body 120, and a tapered radiopaque marker 140 disposed on the distal portion 124 of the tubular body 120 proximate the distal port 128, such that the location of the distal tip 138 within the patient's vasculature system, or relative to the partially or fully deployed intravascular implant 102, can be identified using medical imaging technology (e.g., fluoroscopy).

[0082]

[0081] The delivery catheter 104 may include one or more, or a plurality of regions along its length having different configurations and / or characteristics. For example, the distal portion 124 of the tubular body 120 may have an outer diameter less than the outer diameter of the proximal portion 122 to reduce the profile of the distal portion 124 and facilitate navigation in tortuous vasculature. Furthermore, the distal portion 124 may be more flexible than the proximal portion 122. Generally, the proximal portion 122 may be formed from material that is stiffer than the distal portion 124, so that the proximal portion 122 has sufficient pushability to advance through the patient’s vascular system, while the distal portion 124 may be formed of a more flexible material, so that the distal portion 124 may remain flexible and track more easily over a guidewire to access remote locations in tortuous regions of the vasculature. In some instances, the proximal portion 122 may include a reinforcement layer, such as a braided layer or coiled layer, to enhance the pushability of the delivery catheter 104. The delivery catheter 104 may include a transition region between the proximal portion 122 and the distal portion 124.

[0082] The tubular body 120 may be composed of suitable polymeric materials, metals and / or alloys, such as polyethylene, stainless steel or other suitable biocompatible materials or combinations thereof. Examples of suitable metals and metal alloys can include stainless steel, such as 304V, 304L, and 316L stainless steel; nickel-titanium alloy such as a superelastic (i.e., pseudoelastic) or linear elastic nitinol; nickel-chromium alloy; nickel-chromium-iron alloy; cobalt alloy; tungsten or tungsten alloys; tantalum or tantalum alloys, gold or gold alloys, MP35-N (having a composition of about 35% Ni, 35% Co, 20% Cr, 9.75% Mo, a maximum 1% Fe, a maximum 1 % Ti, a maximum 0.25% C, a maximum 0.15% Mn, and a maximum 0.15% Si); or the like; or other suitable metals, or combinations or alloys thereof. Examples of some suitable polymers can include, but are not limited to, polyoxymethylene (POM), polybutylene terephthalate (PBT), polyether block ester, polyether block amide (PEBA), fluorinated ethylene propylene (FEP), polyethylene (PE), polypropylene (PP), polyvinylchloride (PVC), polyurethane, polytetrafluoroethylene (PTFE), polyether-ether ketone (PEEK), polyimide, polyamide, polyphenylene sulfide (PPS), polyphenylene oxide (PPO), polysufone, nylon, perfluoro(propyl vinyl ether) (PFA), polyether-ester, polymer / metal composites, or mixtures, blends or combinations thereof.

[0083]

[0083] The tubular body 120 may include a braided-shaft construction of stainless steel flat wire that is encapsulated or surrounded by a polymer coating. By way of non-limiting example, HYDROLENE is a polymer coating that may be used to cover the exterior portion of the tubular body 120. Of course, the implant delivery system 100 is not limited to a particular construction or type of delivery catheter 104 and other constructions known to those skilled in the art may be used for the tubular body 120 of the delivery catheter 104. The inner lumen 126 may be advantageously coated with a lubricious coating (not shown), such as PTFE, to reduce frictional forces between the tubular body 120 and the pusher member assembly 108 and intravascular implant 102 when axially translated within the inner lumen 126.

[0084]

[0084] The introducer sheath 106 may, e.g., have a length about 50cm-100cm, and is configured for being introduced through the RHV into axial alignment with the delivery catheter 104 to facilitate loading of the intravascular implant 102 into the inner lumen 126 of the delivery catheter 104. As best shown in Figs. 6 and 7A, the introducer sheath 106 comprises an elongate tubular body 142 having a proximal end 144 and a distal end 146, and an inner lumen 148 axially extending entirely through the tubular body 142. The inner lumen 148 is sized to accommodate axial translation of the radially collapsed intravascular implant 102 and the pusher member assembly 108. The diameters of the tubular body 142 and inner lumen 148 of the introducer sheath 106 are respectively consistent with the diameters of the tubular body 120 and inner lumen 126 of the delivery catheter 104, such that any discontinuity between the inner sheath lumens 40, 60 may be minimized when the introducer sheath 106 is introduced into the RHV in axial alignment with the delivery catheter 104, thereby facilitating transfer of the intravascular implant 102 from the introducer sheath 106 to the delivery catheter 104. The inner lumen 148 terminates at a distal port 150 at the distal end 146 of the tubular body 142.

[0085]

[0085] The pusher member assembly 108 is configured for being slidably disposed in an inner member lumen of an elongate tubular member (in this case, the inner lumen 126 of the delivery catheter 104 or the inner lumen 148 of the introducer sheath 106), with the intravascular implant 102 coaxially disposed between the delivery catheter 104 or the introducer sheath 106 and the pusher member assembly 108, as will be described in further detail below. The pusher member assembly 108 is configured for engaging the intravascular implant 102 when the pusher member assembly 108 is axially translated within the inner lumen 148 of the introducer sheath 106 for transfer to the inner lumen 126 of the delivery catheter 104, and axially translated within the inner lumen 126 of the delivery catheter 104 for delivery of the intravascular implant 102 at a target site of a patient or resheathing the intravascular implant 102 back into the inner lumen 126 of the delivery catheter 104.

[0086]

[0086] As best shown in Figs. 7A-7C, the pusher member assembly 108 generally comprises an elongate pusher member in the form of a delivery wire 152 having a proximal portion 154 that extends proximally from the proximal end of the delivery catheter 104 or the proximal end of the introducer sheath 106 for grasping by the physician, a distal portion 156 that carries the intravascular implant 102, and a transition portion 158 between the proximal portion 154 and the distal portion 156 for facilitating tracking of the pusher member assembly 108 within the inner lumen 126 of the delivery catheter 104 when disposed in the tortuous vasculature of the patient.

[0087]

[0087] The delivery wire 152 may be composed of a conventional guidewire, torqueable cable tube, or a hypotube. In either case, there are numerous materials that can be used for the delivery wire 152 to achieve the desired properties that are commonly associated with medical devices. Some examples can include metals, metal alloys, polymers, metal-polymer composites, and the like, or any other suitable material (e.g., nickel-titanium alloy, stainless steel, a composite of nickel-titanium alloy and stainless steel). In some cases, the delivery wire 152 can be made of the same material along its length, or in some embodiments, can include portions or sections made of different materials. In some embodiments, the material used to construct the delivery wire 152 is selected to impart varying flexibility and stiffness characteristics to different portions of the delivery wire 152. For example, the proximal portion 154, distal portion 156, and transition portion 158 of the delivery wire 152 may be formed of different materials, for example materials having different moduli of elasticity, resulting in a difference in flexibility. For example, the proximal portion 154 can be formed of stainless steel, and the distal portion 156 and transition portion 158 can be formed of a nickel-titanium alloy. However, any suitable material or combination of material may be used for the delivery wire 152, as desired.

[0088]

[0088] In the illustrated embodiment, the pusher member assembly 108 further comprises a coil 160 affixed to the transition portion 158 of the delivery wire 152. The diameter of the transition portion 158 with the coil 160 is closely toleranced to the diameter of the inner sheath lumens 40, 60 of the delivery catheter 104 and introducer sheath 106 to facilitate stable tracking of the pusher member assembly 108 through the inner sheath lumens 40, 60. The coil 160 provides columnar support to the pusher member assembly 108 just proximal to the distal portion 156 on which the intravascular implant 102 is disposed while maintaining lateral flexibility of the pusher member assembly 108. The diameter of the distal portion 156 of the delivery wire 152 is decreased, thereby providing a platform on which the intravascular implant 102, in its collapsed delivery configuration, as well as other components of the pusher member assembly 108 (described in further detail below), are disposed, such that the outer diameter of the radially collapsed intravascular implant 102 and the distal portion of the pusher member assembly 108 are also closely toleranced to the diameter of the inner sheath lumens 40, 60 of the delivery catheter 104 and introducer sheath 106.

[0089]

[0089] The pusher member assembly 108 further comprises an atraumatic distal tip member 162 affixed to the distal end of the delivery wire 152. The distal tip member 162 allows for vessel selection and facilitates navigation of the delivery catheter 104 to the targeted implantation site. The distal tip member 162 may be preshaped to assume a curved geometry (and in the preferred embodiment, J-shaped geometry) when unconstrained, and to assume a straight geometry when constrained. Alternatively, the distal tip member 162 may be floppy, e.g., composed of a soft coil member. The distal tip member 162 may optionally be radiopaque to aid in its visualization using medical imaging technology (e.g., fluoroscopy).

[0090]

[0090] As best illustrated in Figs. 7A-7D, the pusher member assembly 108 further comprises a proximal bumper 164 affixed to the beginning of the distal portion 156 of the delivery wire 152, and a distal bumper 166 affixed to the distal portion 156 of the delivery wire 152 distal to the proximal bumper 164 (e.g., via epoxy bonding), thereby creating a space 168 (and in this case, an annular space) between the bumpers 164, 166 for retaining the radially collapsed intravascular implant 102. The bumpers 164, 166 may be composed of a suitable biocompatible material, such as stainless steel or nitinol. Each of the bumpers 164, 166 is disk-shaped, and is sized to slide within the inner lumens 126, 148 of the delivery catheter 104 and introducer sheath 106, although in alternative embodiments, the bumpers 164, 166 may have any suitable shape. In the illustrated embodiment, the diameter of the proximal bumper 164 is closely toleranced with the diameter of the inner lumens 126, 148 of the delivery catheter 104 and introducer sheath 106, while the distal bumper 166 has a tip that is tapered towards the distal direction to minimize tissue trauma. The outer surfaces of the bumpers 164, 166 may impart low-friction due to the material from which they are formed. Alternatively, or additionally, the outer surfaces of the bumpers 164, 166 may be coated with a lubricious coating, e.g., polytetrafluoroethylene (PTFE), hereby facilitating movement of the bumpers 164, 166 through the inner lumen 126.

[0091]

[0091] One or both of the bumpers 164, 166 may be radiopaque, and thus, also serve as markers that may assist in locating the intravascular implant 102 relative to the delivery catheter 104 using medical imaging technology (e.g., fluoroscopy). For example, such radiopaque proximal bumper 164 may indicate the proximal end 112 of the intravascular implant 102, so that full deployment of the intravascular implant 102 from the delivery catheter 104 can be confirmed, while such radiopaque distal bumper 166 may indicate the point-of-no-return as the intravascular implant 102 is being deployed from the delivery catheter 104, after which the intravascular implant 102 may no longer be resheathed into the delivery catheter 104. To this end, the bumpers 164, 166 may be composed of a suitably radiopaque material, such as, e.g., platinum, gold, tungsten, or alloys thereof or other metals. The pusher member assembly 108 may optionally comprise additional radiopaque elements anywhere along its length to facilitate its visualization using medical imaging technology (e.g., fluoroscopy).

[0092]

[0092] Significantly, the pusher member assembly 108 is configured for cooperating with the intravascular implant 102, such that, without damaging the proximal end 112 or the distal end 114 of the intravascular implant 102 or the inner lumens 126, 148 of the delivery catheter 104 and introducer sheath 106 or generating particles at the proximal end 112 or distal end 114 of the intravascular implant 102, the intravascular implant 102 may be proximally or distally loaded into the inner lumen 148 of the introducer sheath 106 to place it in its radially constrained deliver configuration, transferred from the inner lumen 148 of the introducer sheath 106 into the inner lumen 126 of the delivery catheter 104 while maintaining its radially collapsed delivery configuration, then axially advanced through the inner lumen 126 and out of the distal port 128 of the delivery catheter 104, such that the intravascular implant 102 may be placed into its radially expanded deployed configuration at the target site in the vasculature of the patient, and if necessary, resheathed back through the distal port 128 and into the inner lumen 126 of the delivery catheter 104.

[0093]

[0093] As best shown in Figs. 7C-7D and 7F-7I, the pusher member assembly 108 further comprises a friction pad 170 and a proximal protection device 172 affixed to the delivery wire 152 within the annular space 168 between the bumpers 164, 166. The friction pad 170 is disposed within the central lumen 116 at the proximal end 112 of the intravascular implant 102, while the proximal protective device 172 covers the proximal end 112 of the intravascular implant 102, and in particular, is coaxially disposed between the proximal end 112 of the intravascular implant 102 and the inner lumen 126 of the delivery catheter 104 (as best shown in Figs. 7F and 7H) or the inner lumen 148 of the introducer sheath 106. In the illustrated embodiment, the intravascular implant 102 extends along the entirety of the friction pad 170 (as shown in Fig. 7F), although it should be appreciated that the intravascular implant 102 may alternatively extend along only a portion of the friction pad 170. The pusher member assembly 108 may further comprise an optional distal protective device 174 (shown in Figs. 7A-7C) affixed to the delivery wire 152 for covering the distal end 114 of the intravascular implant 102, and in particular, is coaxially disposed between the distal end 114 of the intravascular implant 102 and the inner lumen 126 of the delivery catheter 104 or the inner lumen 148 of the introducer sheath 106.

[0094]

[0094] The friction pad 170, proximal protective device 172, and distal protective device 174 are configured for cooperating with the intravascular implant 102, such that the pusher member assembly 108 engages the intravascular implant 102 when the intravascular implant 102 is in the collapsed delivery configuration within the inner lumen 126 of the delivery catheter 104 (shown in Figs. 7F and 7H) or the inner lumen 148 of the introducer sheath 106, and releases the intravascular implant 102 when the intravascular implant 102 is in the expanded deployed configuration outside of the inner lumen 126 of the delivery catheter 104 and outside of the inner lumen 148 of the introducer sheath 106 (shown in Figs. 7G and 71).

[0095]

[0095] In particular, the friction pad 170 and the proximal protective device 172 are configured for frictionally engaging the intravascular implant 102 (by sandwiching the proximal end 112 of the intravascular implant 102) therebetween to facilitate distal or proximal axial translation of the intravascular implant 102 within the inner lumen 126 of the delivery catheter 104 (e.g., such that the intravascular implant 102 may be deployed from the inner lumen 126 of the delivery catheter 104 into the radially expanded deployed configuration at the target tissue site in the vasculature of the patient or resheathed back into the inner lumen 126 of the delivery catheter

[0096] 104 prior to deployment of the of the intravascular implant 102) or distal axial translation of the intravascular implant 102 within the inner lumen 148 of the introducer sheath 106 (e.g., such that the intravascular implant 102 may be transferred from the inner lumen 148 of the introducer sheath 106 to the inner lumen 126 of the delivery catheter 104 while maintained in the radially collapsed delivery configuration).

[0097]

[0096] To this end, the proximal protective device 172 is configured for alternately being in a radially collapsed configuration when radially constrained by the inner lumen 126 of the delivery catheter 104 (shown in Figs. 7F and 7H) or the inner lumen 148 of the introducer sheath 106, and for being in a radially expanded configuration when not radially constrained by the inner lumen 126 of the delivery catheter 104 (shown in Figs. 7H and 7J). When in the radially collapsed configuration, the proximal protective device 172 urges the proximal end 112 of the intravascular implant 102 against the friction pad 170 (shown by arrows in Fig. 7F), thereby sandwiching the proximal end 112 of the intravascular implant 102 between the friction pad 170 and the proximal protective device 172. When in the radially expanded configuration, the proximal protective device 172 no longer urges the proximal end 112 of the intravascular implant 102 against the friction pad 170, thereby releasing the proximal end 112 of the intravascular implant 102 from between the friction pad 170 and the proximal protective device 172.

[0098]

[0097] Like the proximal protective device 172, the optional distal protective device 174 is configured for alternately being in a radially collapsed configuration when radially constrained by the inner lumen 126 of the delivery catheter 104 or the inner lumen 148 of the introducer sheath 106, and for being in a radially expanded configuration when not radially constrained by the inner lumen 126 of the delivery catheter 104. When in the radially collapsed configuration, the distal protective device 174 frictionally engages the distal end 114 of the intravascular implant 102. When in the radially expanded configuration, the distal protective device 174 releases the distal end 114 of the intravascular implant 102. The distal protective device 174 may comprise an axial lumen (not shown) in which the delivery wire 152 is disposed. Further details of distal protective devices for intravascular implants are disclosed in U.S. Patent Publication No. 2021 / 0038362, which is expressly incorporated herein by reference.

[0099]

[0098] In the illustrated embodiment, the proximal protective device 172 and the distal protective device 174 are self-expanding, such that they automatically assume the radially expanded configuration when not radially constrained by the inner lumen 126 of the delivery catheter 104 or the inner lumen 148 of the introducer sheath 60. In alternative embodiments, one or both of the proximal protective device 172 and the distal protective device 174 assumes the radially expanded configuration only in response to radially outward expansion forces applied thereto by the self-expanding intravascular implant 102 when deployed from the delivery catheter 104.

[0100]

[0099] The proximal protective device 172 is configured for slidably bearing against the inner lumens 126, 148 of the delivery catheter 104 and introducer sheath 106 (e.g., such that the proximal end 112 of the intravascular implant 102 and the inner lumens 126, 148 of the delivery catheter 104 and introducer sheath 106 are protected during proximal loading of the intravascular implant 102 into the inner lumen 148 of the introducer sheath 106 or during resheathing of the intravascular implant 102 into the inner lumen 126 of the delivery catheter 104). Similarly, the distal protective device 174 is configured for slidably bearing against the inner lumens 126, 148 of the delivery catheter 104 and introducer sheath 106 (e.g., such that the distal end 114 of the intravascular implant 102 and inner lumen 148 of the introducer sheath 106 are protected during distal loading of the intravascular implant 102 into the inner lumen 148 of the introducer sheath 106, or the distal end 114 of the intravascular implant 102 and inner lumens 148, 126 of the introducer sheath 106 and delivery catheter 104 are protected during transfer of the intravascular implant 102 from the introducer sheath 106 to the delivery catheter 104, or during distal advancement through the delivery catheter 104).

[0101]

[0100] As best shown in Figs. 7D and 7F-7I, the friction pad 170 comprises a body 176 (shown partially in phantom) having a proximal end 178 and a distal end 180, and an axial lumen 182 extending entirely through the body 176 and in which the delivery wire 152 is disposed. In one alternative embodiment, the friction pad 170 may be coated with a high friction, tacky material. In another alternative embodiment, the outer surface of the friction pad 170 may be modified to provide the desired resistance for frictionally engaging the intravascular implant 102. For example, at least a portion of the outer surface of the friction pad 170 may be roughened by any suitable technique, such as grit blasting, plasma treatment, or knurling, or lateral grooves, protuberances, or rings may be formed on at least a portion of the outer surface of the friction pad 170. Although the friction pad 170 is generally cylindrical in nature in the illustrated embodiment, in alternative embodiments, the friction pad 170 may have non-circular cross-sectional profiles (e.g., octagonal).

[0102]

[0101] As best shown in Figs. 7D and 7F-7I, the proximal protective device 172 comprises a one or more radially collapsible / expandable element(s) 184 and a base 186 disposed proximal to the friction pad 170. The base 186 has a body 188 and an axial lumen 190 (shown in Fig. 7D) extending through the body 188. In the illustrated embodiment, the body 188 of the base 186 is coextensive with the axial lumen 182 of the friction pad 170 for disposition of the delivery wire 152 therein. The base 186 has a profile (in this case, a radius), that is greater than the profile (in this case, the radius) of the friction pad 170. Thus, the base 186 has a ledge 192 (in this case, an annular ledge) that forms a distal face 194 (shown in Fig. 7D) formed between the base 186 and the friction pad 170 and to which the radially collapsible / expandable element(s) 184 are affixed. In this manner, radially collapsible / expandable elements 184 distally extend from the base 186, overlapping the body 176 of the friction pad 170, thereby sandwiching the proximal end 1 12 of the intravascular implant 102 between the friction pad 170 and the radially collapsible / expandable element(s) 184, as illustrated in Figs. 7F and 7H). Although the base 186 is generally cylindrical in nature in the illustrated embodiment, in alternative embodiments, the base 186 may have non-circular cross-sectional profiles (e.g., octagonal). The radius of the base 186 is preferably greater than the radius of the body 176 of the friction pad 170 to facilitate the disposition of the collapsible / expandable element(s) 184 distally extending therefrom over the friction pad 170.

[0103]

[0102] The friction pad 170, proximal protective device 172, and optional distal protective device 174 are affixed relative to the delivery wire 152, such that the pusher member assembly 108 moves as an integral unit within the inner lumen 126 of the delivery catheter 104 and the inner lumen 148 of the introducer sheath 106. To this end, the proximal bumper 164 abuts the base 186 of the proximal protective device 172, such that the friction pad 170 and proximal protective device 172 axially translate together with the delivery wire 152 as the pusher member assembly 108 is translated relative to the delivery catheter 104 or the introducer sheath 106 in the distal direction (e.g., to deploy the intravascular implant 102 from the delivery catheter 104 or to transfer the intravascular implant 102 from the introducer sheath 106 to the delivery catheter 104). Similarly, the distal bumper 166 abuts the distal end 180 of body 176 of the friction pad 170, such that the friction pad 170 and proximal protective device 172 axially translate together with the delivery wire 152 as the pusher member assembly 108 is translated relative to the delivery catheter 104 or the introducer sheath 106 in the proximal direction (e.g., during resheathing of the intravascular implant 102 within the delivery catheter 104 or proximal loading of the intravascular implant 102 into the introducer sheath 106). The distal protective device 174 may be affixed to the delivery wire 152 via one or more locking members (not shown).

[0104]

[0103] It should be appreciated that the increased frictional force imparted by the collapsed element(s) 184 of the proximal protective device 172 onto the proximal end 112 of the intravascular implant 102 by the sandwiching of the proximal end 112 of the intravascular implant 102 enables the friction pad 170 to be composed of a higher durometer material. Thus, not only does the proximal protective device 172 minimize damage to the proximal end 112 of the intravascular implant 102 and the inner lumens inner lumens 126, 148 of the delivery catheter 104 and introducer sheath 106 and the potential for particle generation at the ends of the intravascular implant 102, the proximal protective device 172 allows the friction pad 170 to be composed of a relatively high durometer biocompatible material. In this manner, the friction pad 170 will not be prone to radial outward bulging when the intravascular implant 102 is axially advanced through the inner lumens 126, 148 of the delivery catheter 104 and introducer sheath 106, which may otherwise prohibitively increase track / resheath force of the intravascular implant 102 and increasing the potential for particle generation at the ends of the intravascular implant 102. Notwithstanding the foregoing, the durometer of the material of which the friction pad 170 is composed is not so high as to hinder the tracking of the delivery catheter 104 around tight curves in the vasculature of the patient. For example, it is preferred that the material of which the friction pad 170 is composed have a relatively high durometer, e.g., greater than 35D, and preferably, in the range of 70D-85D to minimize radial bulging of the friction pad 170 while not hindering the tracking of the delivery catheter 104 around tight curves in the vasculature of the patient. As examples, the friction pad 170 may be composed of a biocompatible polymer, such as, low-density polyethylene (LDPE), thermoplastic elastomer (TPE), thermoplastic polyurethane (TPU), polytetrafluoroethylene (PTFE), polylactic acid (PLA), and preferably, more ridge biocompatible plastics that minimize radial bulging of the friction pad 170, such as polypropylene (PP), liquid crystal polymer (LCP), acrylonitrile butadiene styrene (ABS), polyamide (PA), acrylic, polycarbonate, polyoxymethylene (POM), polyether ether ketone (PEEK), polyetherimide (PEI), and polyamide-imide (PAI).

[0105]

[0104] In one preferred embodiment, the friction pad 170 and proximal protective device 172 are formed together as a monolithic retaining structure (i.e., the friction pad 170 and proximal protective device 172 are formed as a single piece. For example, certain specific configurations of monolithic retaining structures described below may be fabricating using a micro-molding process, which is quicker than other types of micro-fabrication processes, such as three-dimensional (3D) printing. Such monolithic retaining structures may be composed of a polyether-based aliphatic thermoplastic polyurethane (e.g., Teloflex™ SG-85A), which has proven to have suitable characteristics for micro-molding.

[0106]

[0105] Referring now to Figs. 8-14, one specific embodiment of a monolithic retaining structure 200a will be described. The monolithic retaining structure 200a comprises a friction pad 170a and a proximal protective device 172a. The proximal protective device 172a comprises a base 186a and one or more radially collapsible / expandable elements in the form of proximally cantilevered arms 184a affixed to the base 186a. The friction pad 170a comprises a body 176a and an axial lumen 182a extending entirely through the body 176a. The base 186a comprises a body 188a and an axial lumen 190a coextensive with the axial lumen 182a of the friction pad 170a and in which the delivery wire 152 (not shown) is disposed. The delivery wire 152 (not shown in Figs. 8-14) may be disposed through the coextensive axial lumens 182a, 190a of the friction pad 170a and base 186a.

[0107]

[0106] In this embodiment, when the proximal protective device 172a is in the radially collapsed configuration (as shown in Figs. 8 and 13) (e.g., when radially constrained by the inner lumen 126 of the delivery catheter 104 or the inner lumen 148 of the introducer sheath 106 (as shown in Figs. 7F and 7H)), the proximally- cantilevered arms 184a are configured for cantilevering inward (i.e. , radially collapsing) toward the friction pad 170a, such that the friction pad 170a and arms 184a axially overlap to frictionally engage, while also protecting, the proximal end 112 of the intravascular implant 102 (see Fig. 13). In contrast, when the proximal protective device 172a is in the radially expanded configuration (as shown in Figs. 9- 12 and 14) (e.g., when not radially constrained by the inner lumen 126 of the delivery catheter 104 or the inner lumen 148 of the introducer sheath 106 (as shown in Figs. 7G and 71)), the arms 184a are configured for cantilevering outward (i.e., radially expanding) away from the friction pad 170a to release the proximal end 112 of the intravascular implant 102 (see Fig. 14). In the illustrated embodiment, the proximal protective device 172a is self-expanding; that is, the arms 184a automatically cantilever outward in response to the removal of the radially constraining force exerted on the proximal protective device 172a by the inner lumen 126 of the delivery catheter 104 or the inner lumen 148 of the introducer sheath 106.

[0108]

[0107] As best shown in Figs. 10-12, the arms 184a are cantilevered at a distal face 194a of the body 188a of the base 186a formed by a ledge 192a between the friction pad 170a and the base 186a, such that each of the arms 184a has a cantilevered end 202 affixed to the base 186a and a free end 204 that distally extends over the friction pad 170a. In this manner, as best illustrated in Fig. 13, the proximal end 112 of the intravascular implant 102 may be sandwiched between, and thus frictionally engaged by, the arms 184a and the body 176a of the friction pad 170a when the proximal protective device 172a is in a radially collapsed configuration. In the illustrated embodiment, the arms 184a extend over only a portion of the friction pad 170a, although in alternative embodiments, the arms 184a may extend over the entirety of the friction pad 170a.

[0109]

[0108] In the illustrated embodiment, the monolithic retaining structure 200a, when the proximal protective device 172a in the radially collapsed configuration, has an annular space 205 (best shown in Fig. 13) located between the friction pad 170a and the arms 184a to accommodate the proximal end 112 of the intravascular implant 102 therein when disposed within the inner lumen 126 of the delivery catheter 104 or the inner lumen 148 of the introducer sheath 106. In the illustrated embodiment, the width (i.e., the dimension along the circumference of the pusher member assembly 108) of each of the arms 184a slightly flares outward from the cantilevered end 202 and free ends 204 towards a center 206 of the arm 184a, thereby facilitating the assembly of the pusher member assembly 108. Alternatively, the width of each of the arms 184a may be uniform from the cantilevered end 202 to the free end 204.

[0110]

[0109] Preferably, the arms 184a are cantilevered at the distal face 194 at the extreme periphery of the base 186a, such that there are no discontinuities between the outer cylindrical surface of the base 186a and the radially outward surfaces of the arms 184a, thereby presenting a smooth surface as the proximal protective device 172a slidably bears against the inner lumen 126 of the delivery catheter 104 or the inner lumen 148 of the introducer sheath 106. Furthermore, such disposition of the arms 184a at the periphery of the base 186a facilitates the accommodation of the intravascular implant 102 between the arms 184a and the friction pad 170a, while allowing the wall of the body 176a of the friction pad 170a and each of the arms 184a to have a suitable thickness (i.e., the dimension along the radius of the pusher member assembly 118) that facilitates the micro-fabrication of the proximal protective device 172a (e.g., if using micro-molding, to allow material to consistently flow through the gaps and spaces of the mold that form the wall of the body 176a and the arms 184a, as well as to minimize fracture of the body 176a and the arms 184a when removed from the mold).

[0111]

[0110] As illustrated in Fig. 8, the arms 184a are configured for cantilevering inward in a non-overlapping fashion when the proximal protective device 172a is in the radially collapsed configuration, thereby minimizing the maximum thickness of the portion of the proximal protective device 172a covering the proximal end 112 of the intravascular implant 102 when radially constrained within the inner lumen 126 of the delivery catheter 104 or the inner lumen 148 of the introducer sheath 106, thereby allowing each of the arms 184a, as well as the wall of the friction pad 170a, to have a thickness suitable for the micro-fabrication of the proximal protective device 172a. Furthermore, it is preferable that the non-overlapping proximally cantilevering arms 184a have suitable spacings sufficient to facilitate the microfabrication of the proximal protective device 172a (e.g., if micro-molding is used, to allow sufficient thicknesses within the mold). It should be appreciated that, although the proximal protective device 172a is illustrated as comprising six proximally cantilevered arms 184a, the proximal protective device 172a may have any plural number of proximally-cantilevered arms 184a, e.g., two, four, or eight. Furthermore, although the arms 184a are illustrated as being equally distributed around the friction pad 170a (i.e. , the widths of and spacings between the arms 184a are equal), the arms 184a may be unequally distributed around the friction pad 90 either because the widths of the arms 184a are different or the spacings therebetween are different. Furthermore, although the arms 184a are illustrated as having identical shapes and sizes, it should be appreciated that the shapes and / or sizes of the arms 184a may be different from each other.

[0112]

[0111] In the illustrated embodiment, the body 188a of the base 186a is chamfered to facilitate proximal loading of the intravascular implant 102 into the introducer sheath 106. That is, the body 188a of the base 186a comprises a distal portion 208 having a uniform radius for accommodating the arms 184a, and an inwardly angled proximal portion 210 that proximally tapers down. Thus, when proximally loading the intravascular implant 102 into the inner lumen 148 of the introducer sheath 106, the inwardly angled proximal portion 210 will first bear against the annular edge at the distal end 146 of the introducer sheath 106, thereby facilitating insertion of the proximal protective element 82a, with the intravascular implant 102, into the inner lumen 148 of the introducer sheath 106. In the illustrated embodiment, the inner surfaces of the tips 212 of the free ends 204 of the arms 184a are rounded, such that the tips 212 do not cause any damage to the intravascular implant 102.

[0113]

[0112] Referring now to Figs. 15-17, another specific embodiment of a monolithic retaining structure 200b will be described. The monolithic retaining structure 200b is similar to the monolithic retaining structure 200a described above in that the monolithic retaining structure 200b comprises the friction pad 170a and a proximal protection device 172b comprising the base 186a and a plurality of proximally cantilevered arms 184b distally extending from the base 186a.

[0114]

[0113] Like the proximally-cantilevered arms 184a of the afore-described proximal protection device 172a, when the proximal protective device 172b is in the radially collapsed configuration (not shown in Figs. 15-17) (e.g., when radially constrained by the inner lumen 126 of the delivery catheter 104 or the inner lumen 148 of the introducer sheath 106 (as shown in Figs. 7F and 7H)), the proximally-cantilevered arms 184b are configured for cantilevering inward (i.e., radially collapsing) toward the friction pad 170a, such that the friction pad 170a and arms 184b axially overlap to frictionally engage, while also protecting, the proximal end 112 of the intravascular implant 102 (not shown in Figs. 15-17). In contrast, when the proximal protective device 172b is in the radially expanded configuration (shown in Figs. 15-17) (e.g., when not radially constrained by the inner lumen 126 of the delivery catheter 104 or the inner lumen 148 of the introducer sheath 106 (as shown in Figs. 7G and 71)), the arms 184b are configured for cantilevering outward (i.e., radially expanding) away from the friction pad 170a to release the proximal end 112 of the intravascular implant 102 (not shown in Figs. 15-17).

[0115]

[0114] However, unlike the proximally-cantilevered arms 184a of the afore- described proximal protection device 172a, which have widths that slightly increase from cantilevered ends 202 and free ends 204 to the centers 206 of the proximally- cantilevered arms 184a, the proximally-cantilevered arms 184b of the proximal protection device 172b continuously angle outward from the cantilevered ends 202 to the free ends 204. That is, each of the arms 184b generally have an isosceles trapezoidal shape, with the cantilevered end 202 representing the short side of the isosceles trapezoid, and the free end 204 representing the long side of the isosceles trapezoid.

[0116]

[0115] In this manner, the narrow widths of the proximally-cantilevered ends 202 facilitate cantilevering of the arms 184b inward (i.e., radially collapsing) when the proximal protective device 172b is in the radially collapsed configuration, and cantilevering of the arms 184b outward (i.e., radially expanding) when the proximal protective device 172b is in the radially expanded configuration. The continuously increasing widths of the free ends 204 maximize coverage of the proximal end 112 of the intravascular implant 102 coaxially disposed between the arms 184b and the friction pad 170a, thereby increasing frictional engagement and protection of the proximal end 112 of the intravascular implant 102 during axial translation of the intravascular implant 102 within the inner lumens 126, 148 of the delivery catheter 104 and introducer sheath 106, as well as during resheathing into the delivery catheter 104 and proximal loading into the introducer sheath 106. It should be appreciated that, because the spacings between the arms 184b of the proximal protection device 172b are less than the spacings between the arms 184a of the monolithic retaining structure 200a, such spacings may not be able to fabricate using micro-molding. Instead, a hollow funnel structure may be fabricated using a micromolding process, and then axial cuts can be made through the wall of the funnel to form the arms 184b. Alternatively, the monolithic structure 200b may be fabricated using an appropriate micro-manufacturing process, e.g., three-dimensional (3D) printing. In the illustrated embodiment, the inner and outer surfaces of the tips 212 of the free ends 204 of the arms 184b are rounded, thereby preventing damage to the intravascular implant 102 that may otherwise be caused by the impingement of the tips 212 of the arms 184b thereon, as well as the inner lumens 126, 148 of the delivery catheter 104 and introducer sheath 106 that may otherwise be caused by the impingement of the tips 212 of the arms 184b thereon during distal advancement of the intravascular implant 102 within the delivery catheter 104 and introducer sheath 106.

[0117]

[0116] Referring now to Figs. 18-24, still another specific embodiment of a monolithic retaining structure 200c will be described. The monolithic retaining structure 200c is similar to the monolithic retaining structure 200a described above in that the monolithic retaining structure 200c comprises a friction pad 170c and a proximal protection device 172c comprising the base 186a of the afore-described proximal protection device 172a and a plurality of proximally cantilevered arms 184c distally extending from the base 186a. The friction pad 170c is similar to the friction pad 170a of the afore-described proximal protection device 172a in that it comprises a body 176c and an axial lumen 182c extending entirely through the body 176c.

[0118]

[0117] Like the proximally-cantilevered arms 184a of the afore-described proximal protection device 172a, when the proximal protective device 172c is in the radially collapsed configuration (shown in Figs. 18 and 23) (e.g., when radially constrained by the inner lumen 126 of the delivery catheter 104 or the inner lumen 148 of the introducer sheath 106 (as shown in Figs. 7F and 7H)), the proximally-cantilevered arms 184c are configured for cantilevering inward (i.e., radially collapsing) toward the friction pad 170c, such that the friction pad 170c and arms 184c axially overlap to frictionally engage, while also protecting, the proximal end 112 of the intravascular implant 102 (shown in Fig. 23). In contrast, when the proximal protective device 172c is in the radially expanded configuration (shown in Figs. 19-22 and 24) (e.g., when not radially constrained by the inner lumen 126 of the delivery catheter 104 or the inner lumen 148 of the introducer sheath 106 (as shown in Figs. 7G and 7I)), the arms 184c are configured for cantilevering outward (i.e., radially expanding) away from the friction pad 170c to release the proximal end 112 of the intravascular implant 102 (shown in Fig. 24).

[0119]

[0118] However, unlike the proximally-cantilevered arms 184a of the afore- described proximal protection device 172a, which have proximally-cantilevered arms 184a that are generally straight, the proximally-cantilevered arms 184c of the proximal protection device 172c have centers 206 that are angled slightly radially outward when the proximal protection device 172c is in the radially collapsed configuration. In this manner, the free ends 204 of the arms 184c will be slightly angled radially inward in the distal direction, thereby minimizing the chance that the free ends 204 of the arms 184c, as they slidably bear against the inner lumens 126, 148 of the delivery catheter 104 and introducer sheath 106, will catch or snag on any discontinuities between the inner lumens 126, 148 (e.g., when transferring the intravascular implant 102 from the introducer sheath 106 to the delivery catheter 104), or will catch or snag on any discontinuities within the inner lumen 126 (e.g., when distally translated within the delivery catheter 104). Notably, when the proximal protection device 172c is in the radially expanded configuration, the cantilevered ends 202 of the arms 184c will cantilever radially outward to the extent that the free ends 204 of the arms 184c extend parallel or nearly parallel to the axis of the friction pad 170c, thereby facilitating the release of the proximal end 112 of the intravascular implant 102.

[0120]

[0119] Like the tips 212 of the free ends 204 of the arms 184b, both the inner and outer surfaces of the tips 212 of the free ends 204 of the arms 184c are rounded, thereby preventing damage to the intravascular implant 102 that may otherwise be caused by the impingement of the tips 212 of the arms 184c thereon, as well as the inner lumens 126, 148 of the delivery catheter 104 and introducer sheath 106 that may otherwise be caused by the impingement of the tips 212 of the arms 184c thereon during distal advancement of the intravascular implant 102 within the delivery catheter 104 and introducer sheath 106. Furthermore, the body 176c of the friction pad 170c has a rounded distal edge 213 (in this case, an annular edge), thereby preventing damage to the intravascular implant 102 that may otherwise be caused by impingement of the distal annular edge 213 of the body 176c on the intravascular implant 102.

[0121]

[0120] Unlike the body 176a friction pad 170a of the afore-described proximal protection device 172a, which generally has a uniform profile along its length, the body 176c of the friction pad 170c has a proximal end 178c that has a non-uniform profile, and in particular, has distal section 214 having a profile (in this case, a diameter) and a proximal section 216 having a profile (in this case, a diameter) less than the profile of the distal section 214, as best illustrated in Figs. 23-24. In this manner, an enlarged space 218 (in this case, an annular space) is formed between the proximal section 216 and the arms 184c of the proximal protective device 172c, such that a portion of the proximal end 122 distal to a proximal annular edge 119 of the intravascular implant 102 is sandwiched between, and thus frictionally engaged by, the distal section 214 of the friction pad 170c and the arms 184c of the proximal protective device 172c, while the proximal annular edge 119 of the intravascular implant 102 is disposed within the enlarged annular space 218. In this manner, engagement between the arms 184c of the proximal protective device 172c and the proximal annular edge 119 of the intravascular implant 102 is avoided, thereby preventing damage to the proximal annular edge 119 of the intravascular implant 102 that may otherwise be caused by its engagement by the arms 184c.

[0122]

[0121] Referring now to Figs. 25-26, yet another specific embodiment of a monolithic retaining structure 200d will be described. The monolithic retaining structure 200d is similar to the monolithic retaining structures 200a-200c described above in that the monolithic retaining structure 200d comprises a friction pad 170d and a proximal protection device 172d comprising the base 186a of the afore- described proximal protection devices 172a-172c and a plurality of radially collapsible / expandable elements 184d distally extending from the base 186a. The friction pad 170d may be identical to the friction pad 170a of the afore-described proximal protection devices 172a, 172b or the friction pad 170c of the afore- described proximal protection device 172c.

[0123]

[0122] Like the proximally-cantilevered arms 184a-184c of the afore-described proximal protection devices 172a-172c, when the proximal protective device 172d is in the radially collapsed configuration (shown in Fig. 25) (e.g., when radially constrained by the inner lumen 126 of the delivery catheter 104 or the inner lumen 148 of the introducer sheath 106 (as shown in Figs. 7F and 7H)), the radially collapsible / expandable elements 184d are configured for cantilevering inward (i.e., radially collapsing) toward the friction pad 170d, such that the friction pad 170d and arms 184d axially overlap to frictionally engage, while also protecting, the proximal end 112 of the intravascular implant 102 (not shown in Figs. 25-26). In contrast, when the proximal protective device 172d is in the radially expanded configuration (shown in Fig. 26) (e.g., when not radially constrained by the inner lumen 126 of the delivery catheter 104 or the inner lumen 148 of the introducer sheath 106 (as shown in Figs. 7G and 71)), the radially collapsible / expandable elements 184d are configured for cantilevering outward (i.e., radially expanding) away from the friction pad 170d to release the proximal end 112 of the intravascular implant 102 (not shown in Figs. 25-26).

[0124]

[0123] However, unlike the radially collapsible / expandable elements 184a-184c of the proximal protection devices 172a-172c, which do not overlap with each other when the proximal protection devices 172a-172c are in the radially collapsed configuration, the radially collapsible / expandable elements 184d take the form of pedals that overlap each other when the proximal protection device 172d is in a radially collapsed configuration, as best shown in Fig. 25. In this case, in order to accommodate the increased thickness of the proximal protection device 172d when in the radially collapsed configuration due to the overlapping regions of the pedals 184d, the pedals 184d are preferably composed of very thin layers of a biocompatible material, such as, e.g., expanded polytetrafluoroethylene (ePTFE), which can be micro-fabricated using a 3D printing technique. It should be appreciated that, although the proximal protective device 172d is illustrated as comprising three proximally cantilevered pedals 184d, the proximal protective device 172d may have any plural number of proximally-cantilevered pedals 184d, e.g., four or six.

[0125]

[0124] Referring now to Figs. 27-29, yet another specific embodiment of a monolithic retaining structure 200e will be described. The monolithic retaining structure 200e is similar to the monolithic retaining structures 200a-200d described above in that the monolithic retaining structure 200e comprises a friction pad 170e and a proximal protection device 172e comprising the base 186a of the afore- described proximal protection devices 172a-172c and a radially collapsible / expandable element 184e distally extending from the base 186a. The friction pad 170e may be identical to the friction pad 170a of the afore-described proximal protection devices 172a, 172b or the friction pad 170c of the afore- described proximal protection device 172c.

[0126]

[0125] Like the proximally-cantilevered arms 184a-184d of the afore-described proximal protection devices 172a-172c, when the proximal protective device 172e is in the radially collapsed configuration (shown in Fig. 27) (e.g., when radially constrained by the inner lumen 126 of the delivery catheter 104 or the inner lumen 148 of the introducer sheath 106 (as shown in Figs. 7F and 7H)), the radially collapsible / expandable element 184e is configured for radially collapsing toward the friction pad 170e, such that the friction pad 170e and radially collapsible / expandable element 184e axially overlap to frictionally engage, while also protecting, the proximal end 112 of the intravascular implant 102 (not shown in Fig. 27). In contrast, when the proximal protective device 172e is in the radially expanded configuration (shown in Figs. 28-29) (e.g., when not radially constrained by the inner lumen 126 of the delivery catheter 104 or the inner lumen 148 of the introducer sheath 106 (as shown in Figs. 7G and 71)), the radially collapsible / expandable element 184e is configured for radially expanding away from the friction pad 170e to release the proximal end 112 of the intravascular implant 102 (not shown in Figs. 28-29).

[0127]

[0126] However, unlike the radially collapsible / expandable elements 184a-184d of the proximal protection devices 172a-172d, which have a plurality of cantilevered collapsible / expandable elements 184, the proximal protection device 172e comprises a single radially collapsible / expandable element 184e that takes the form of a shroud. When proximal protective device 172e is in the radially expanded configuration, the shroud 184e flares distally outward from the base 186a of the proximal protection device 172e, as illustrated in Figs. 28-29. In the illustrated embodiment, the wall of the funnel 184e has corrugations 220 to facilitate transition of the proximal protective device 172e from the radially expanded configuration (shown in Figs. 28-29) to the radially collapsed configuration (shown in Fig. 27). In order to accommodate the increased thickness of the proximal protection device 172e when in the radially collapsed configuration due to the overlapping regions in the corrugations 220 of the shroud 184e, the wall of the shroud 184e is preferably composed of a very thin layer of a biocompatible material, such as, e.g., expanded polytetrafluoroethylene (ePTFE), which can be micro-fabricated using a 3D printing technique.

[0128]

[0127] Having described an intravascular implant loading assembly (i.e. , the coaxially arrangement of the intravascular implant 102, introducer sheath 106, and pusher member assembly 108), one method 250 of manufacturing an intravascular implant loading assembly will now be described with reference to Fig. 30.

[0129]

[0128] First, the delivery wire 152 is threaded through the axial lumen 182 of the friction pad 170, the axial lumen 190 of the proximal protective device 172, and the axial lumen of the distal protective device 174 (step 252). Next, the friction pad 170, proximal protective device 172, and distal protective device 174 are axially affixed to the delivery wire 152 to form pusher member assembly 108 (step 254). For example, the proximal bumper 164 may be affixed to the delivery wire 152 proximal to the friction pad 170 and the proximal protective device 172, the distal bumper 166 may be affixed to the delivery wire 152 distal to the friction pad 170 and distal protective device 172, and the distal protective device 174 may be affixed to the delivery wire 152 via a locking member.

[0130]

[0129] Then, the friction pad 170 is disposed within the central lumen 116 of the intravascular implant 102 at the proximal end 112 of the intravascular implant 102 while the intravascular implant 102 is in the radially expanded configuration (step 256). While in their radially expanded configurations, the proximal protective device 172 and distal protective device 174 are then disposed respectively over the proximal end 122 and distal end 114 of the intravascular implant 102, thereby forming a concentric arrangement (best shown in Figs. 7H and 7I) with the intravascular implant 102 and the pusher member assembly 108 (step 258).

[0131]

[0130] Lastly, the intravascular implant 102 is loaded into the inner lumen 148 of the introducer sheath 106, such that the inner lumen 148 radially constrains the proximal protective device 172 and intravascular implant 102 into their respective radially collapsed configurations (step 260). In the preferred method, the friction pad 170 and the proximal protective device 172 axially overlap, such that the proximal end 112 of the intravascular implant 102 is sandwiched between, and therefore frictionally engaged by, the friction pad 170 and the proximal protective device 172 in the concentric arrangement.

[0132]

[0131] In one method, the intravascular implant 102 is proximally loaded into the inner lumen 148 of the introducer sheath 106 (i.e., the proximal end 112 of the intravascular implant 102 is loaded first into the distal port 150 of the introducer sheath 106) as the proximal protective device 172 slidably bears against the inner lumen 148 of the introducer sheath 106, thereby minimize any damage to the proximal end 112 of the intravascular implant 102 and the inner lumen 148 of the introducer sheath 106, while also minimizing deposition of foreign matter within the inner lumen 148 of the introducer sheath 106. By proximally loading the concentric arrangement into the inner lumen 148 of the introducer sheath 106, the distance that the intravascular implant 102 needs to travel through the inner lumen 148 to locate it at the distal end 146 of the introducer sheath 106 is minimized.

[0132] Although particular embodiments of the present inventions have been shown and described, it will be understood that it is not intended to limit the present inventions to the preferred embodiments, and it will be obvious to those skilled in the art that various changes and modifications may be made without departing from the spirit and scope of the present inventions. Thus, the present inventions are intended to cover alternatives, modifications, and equivalents, which may be included within the spirit and scope of the present inventions as defined by the claims.

Claims

What is claimed is:

1. An intravascular implant delivery system, comprising: an intravascular implant comprising a central lumen, alternately having a radially collapsed delivery configuration and a radially expanded deployed configuration; an elongate tubular member having an inner member lumen in which the intravascular implant is disposed when in the radially collapsed delivery configuration; and a pusher member assembly slidably disposed in the inner member lumen, comprising an elongate pusher member, a friction pad affixed relative to the pusher member and disposed within the central implant lumen, and a proximal protective device affixed relative to the pusher member and coaxially disposed between a proximal end of the intravascular implant and the inner member lumen, the friction pad having an axial pad lumen within which the pusher member is disposed.

2. The intravascular implant delivery system of claim 1 , wherein the friction pad is configured for frictionally engaging the intravascular implant while the proximal protective device is configured for slidably bearing against the inner member lumen as the pusher member assembly slides in the inner member lumen.

3. The intravascular implant delivery system of claim 2, wherein the delivery sheath is an introducer sheath having a distal end configured for being axially aligned with a proximal end of a delivery catheter having an inner catheter lumen, and wherein the friction pad is configured for frictionally engaging the intravascular implant and the proximal protective device is configured for slidably bearing against the inner member lumen and the inner catheter lumen when the pusher member assembly slides in the inner member lumen and inner catheter lumen, such that the intravascular implant may be transferred from the inner member lumen to the inner catheter lumen while maintained in the radially collapsed delivery configuration.

4. The intravascular implant delivery system of claim 2, wherein the delivery sheath is a delivery catheter configured for being navigated through a vasculature to a desired target site of a patient, and the inner member lumen is an inner catheterlumen, wherein the friction pad is configured for frictionally engaging the intravascular implant and the proximal protective device is configured for slidably bearing against the inner member lumen when the pusher member assembly slides in the inner member lumen, such that the intravascular implant may be deployed from the inner catheter lumen into the radially expanded deployed configuration at the target tissue site.

5. The intravascular implant delivery system of claim 4, wherein the friction pad is configured for frictionally engaging the intravascular implant while the proximal protective device is configured for slidably bearing against the inner member lumen when the pusher member assembly slides in the inner member lumen, such that the intravascular implant may be resheathed back into the radially collapsed delivery configuration within the inner catheter lumen.

6. The intravascular implant delivery system of any of claims 1-5, wherein the intravascular implant is one of a stent, a stent graft, a flow-diverter, a vaso-occlusive device, and a vena cava filter.

7. The intravascular implant delivery system of any of claims 1-6, wherein the pusher member assembly further comprises a proximal bumper and a distal bumper affixed to the pusher member, thereby forming an annular space therebetween in which the friction pad and proximal protective device are disposed.

8. The intravascular implant delivery system of any of claims 1-7, wherein the pusher member is a delivery wire.

9. The intravascular implant delivery system of any of claims 1-8, wherein the pusher member assembly further comprises a distal protective device affixed relative to the pusher member and coaxially disposed between a distal end of the intravascular implant and the inner member lumen.

10. The intravascular implant delivery system of any of claims 1-9, wherein the friction pad and the proximal protective device axially overlap, such that the proximalend of the intravascular implant is sandwiched between the friction pad and the proximal protective device.

11. The intravascular implant delivery system of claim 10, wherein the friction pad has a distal section having a first profile and a proximal section having a second profile less than the first profile, thereby forming an enlarged space between the proximal section of the friction pad and the proximal protective device, such that a portion of a proximal end distal to a proximal edge of the intravascular implant is sandwiched between the distal section of the friction pad and the proximal protective device, while the proximal edge of the intravascular implant is disposed within the enlarged space.

12. The intravascular implant delivery system of any of claims 1-10, wherein the friction pad and the proximal protective device form a monolithic structure.

13. The intravascular implant delivery system of any of claims 1-12, wherein the proximal protective device is self-expanding.

14. The intravascular implant delivery system of any of claims 1-13, wherein the proximal protective device is configured for alternately being in a radially collapsed configuration when radially constrained by the inner member lumen, thereby engaging the proximal end of the intravascular implant, and for being in a radially expanded configuration when not radially constrained by the inner member lumen, thereby releasing the proximal end of the intravascular implant.

15. The intravascular implant delivery system of claim 14, wherein the proximal protective element comprises a plurality of radially collapsible / expandable elements configured for radially collapsing when the proximal protective device is in the radially collapsed configuration, and for radially expanding when the proximal protective device is in the radially expanded configuration.

16. The intravascular implant delivery system of claim 15, wherein the proximal protective element further comprises a base proximal to the friction pad, the base having a profile greater than a profile of the friction pad, the base having a ledgeforming a distal face from which the plurality of radially collapsible / expandable elements extends.

17. The intravascular implant delivery system of claim 16, wherein the plurality of radially collapsible / expandable elements comprise a plurality of proximally- cantilevered arms configured for cantilevering outward when the proximal protective device is in the radially expanded configuration, and for cantilevering inward when the proximal protective device is in the radially collapsed configuration.

18. The intravascular implant delivery system of claim 17, wherein the plurality of proximally cantilevered arms are configured for cantilevering inward in a nonoverlapping fashion when the proximal protective device is in the radially collapsed configuration.

19. The intravascular implant delivery system of claim 17, wherein the plurality of proximally cantilevered arms extend over the friction pad, thereby sandwiching the proximal end of the intravascular implant between the friction pad and the plurality of proximally-cantilevered arms.

20. The intravascular implant delivery system of claim 17, wherein a center of each of the plurality of proximally cantilevered arms is angled radially outward.21 . The intravascular implant delivery system of claim 17, wherein the number of the plurality of proximally cantilevered arms is at least four.

22. The intravascular implant delivery system of claim 17, wherein the proximally cantilevered arms are distributed equally around a circumference of the friction pad.

23. The intravascular implant delivery system of any of claims 1-22, wherein the friction pad has a durometer greater than 35D.

24. The intravascular implant delivery system of claim 23, wherein the friction pad has a durometer in the range of 70D-85D.

25. The intravascular implant deliver system of any of claims 1 -24, wherein the friction pad is cylindrical.

26. A pusher member assembly configured for translating an intravascular implant having a radially collapsed delivery configuration when radially constrained within an inner member lumen of an elongate tubular member and a radially expanded deployed configuration when not radially constrained within the inner member lumen, comprising: an elongate pusher member; a friction pad affixed relative to the pusher member and being configured for being disposed within a central implant lumen of the intravascular implant when the intravascular implant is in the radially collapsed delivery configuration, the friction pad having an axial pad lumen in which the pusher member is disposed; and a proximal protective device affixed relative to the pusher member and being configured for being coaxially disposed between a proximal end of the intravascular implant and the inner member lumen when the intravascular implant is in the radially collapsed delivery configuration.

27. The pusher member assembly of claim 26, wherein the friction pad is configured for frictionally engaging the intravascular implant when the intravascular implant is in the radially collapsed delivery configuration while proximal protective device is configured for slidably bearing against the inner member lumen as the pusher member assembly slides in the inner member lumen when the proximal protective device is between the proximal end of the intravascular implant and the inner member lumen.

28. The pusher member assembly of claim 26, further comprising a proximal bumper and a distal bumper affixed to the pusher member, thereby forming a space therebetween, wherein the friction pad and proximal protective device are disposed within the space.

29. The pusher member assembly of claim 26, wherein the pusher member is a delivery wire.

30. The pusher member assembly of claim 26, wherein the pusher member assembly further comprises a distal protective device affixed relative to the pusher member and configured for being coaxially disposed between a distal end of the intravascular implant and the inner member lumen when the intravascular implant is in the radially collapsed delivery configuration.31 . The pusher member assembly of claim 26, wherein the friction pad and the proximal protective device axially overlap, such that the proximal end of the intravascular implant is configured for being sandwiched between the friction pad and the proximal protective device when the intravascular implant is in the radially collapsed delivery configuration.

32. The pusher member assembly of claim 31 , wherein the friction pad has a distal section having a first profile and a proximal section having a second profile less than the first profile, thereby forming an enlarged space between the proximal section of the friction pad and the proximal protective device, such that a portion of the proximal end distal to a proximal edge of the intravascular implant is configured for being sandwiched between the distal section of the friction pad and the proximal protective device when the intravascular implant is in the radially collapsed delivery configuration, while the proximal edge of the intravascular implant is configured for being disposed within the enlarged space.

33. The pusher member assembly of claim 26, wherein the friction pad and the proximal protective device form a monolithic structure.

34. The pusher member assembly of claim 26, wherein the proximal protective device is self-expanding.

35. The pusher member assembly of claim 26, wherein the proximal protective device is configured for alternately being in a radially collapsed configuration when radially constrained within the inner member lumen, thereby engaging the proximal end of the intravascular implant, and for being in a radially expanded configurationwhen not radially constrained within the inner member lumen, thereby releasing the proximal end of the intravascular implant.

36. The pusher member assembly of claim 35, wherein the proximal protective element comprises a plurality of radially collapsible / expandable elements configured for radially collapsing when the proximal protective device is in the radially collapsed configuration, and for radially expanding when the proximal protective device is in the radially expanded configuration.

37. The pusher member assembly of claim 36, wherein the proximal protective element further comprises a base proximal to the friction pad, the base having a profile greater than a profile of the friction pad, the base having a ledge forming a distal face from which the plurality of radially collapsible / expandable elements extends.

38. The pusher member assembly of claim 37, wherein the plurality of radially collapsible / expandable elements comprise a plurality of proximally-cantilevered arms configured for cantilevering outward when the proximal protective device is in the radially expanded configuration, and for cantilevering inward when the proximal protective device is in the radially collapsed configuration.

39. The pusher member assembly of claim 38, wherein the plurality of proximally cantilevered arms are configured for cantilevering inward in a nonoverlapping fashion when the proximal protective device is in the radially collapsed configuration.

40. The pusher member assembly of claim 38, wherein the plurality of proximally-cantilevered arms extend over the friction pad, such that the proximal end of the intravascular implant is configured for being sandwiched between the friction pad and the plurality of radially collapsible / expandable elements when the intravascular implant is in the radially collapsed delivery configuration.41 . The pusher member assembly of claim 38, wherein a center of each of the plurality of proximally cantilevered arms is angled radially outward.

42. The pusher member assembly of claim 38, wherein the number of the plurality of proximally cantilevered arms is at least four.

43. The pusher member assembly of claim 38, wherein the plurality of proximally cantilevered arms are equally distributed around a circumference of the friction pad.

44. The pusher member assembly of claim 26, wherein the friction pad has a durometer greater than 35D45. The pusher member assembly of claim 26, wherein the friction pad has a durometer in the range of 70D-85D.

46. The pusher member assembly of claim 26, wherein the friction pad is cylindrical.

47. A monolithic medical device for protecting a proximal end of an intravascular implant having a central implant lumen, comprising: a friction pad having a pad body sized to be received in the central implant lumen and an axial pad lumen configured for receiving a pusher member; a base proximal to the pad body, the base having a profile greater than a profile of the pad body, such that a ledge having a distal face is formed between the base and the friction pad; and a plurality of arms distally extending from the distal face, such that, when radially constrained, are configured for being cantilevered toward the friction pad, such that friction pad and plurality of arms axially overlap to frictionally engage the proximal end of the intravascular implant, and when radially unconstrained, being configured for being cantilevered away from the friction pad to release the proximal end of the intravascular implant.

48. The monolithic medical device of claim 47, wherein the pad body has a distal section having a first profile and a proximal section having a second profile less than the first profile, thereby forming an enlarged space between the proximal section of the pad body and the plurality of arms, such that a portion of the proximal end distalto a proximal edge of the intravascular implant is configured for being sandwiched between the distal section of the friction pad and the proximal protective device, while the proximal edge of the intravascular implant is configured for being disposed within the enlarged space.

49. The monolithic medical device of claim 47, wherein the plurality arms have a flattened profile.

50. The monolithic medical device of claim 47, wherein a center of each of the plurality of arms is angled radially outward.

51. The monolithic medical device of claim 47, wherein the number of the plurality of arms is at least four.

52. The monolithic medical device of claim 47, wherein the plurality of arms are equally distributed around a circumference of the friction pad.

53. The monolithic medical device of claim 47, wherein the friction pad, base, and plurality of arms have a durometer greater than 35D54. The monolithic medica device of claim 47, wherein the friction pad has a durometer in the range of 70D-85D.

55. The monolithic medical device of claim 47, wherein the friction pad and base are cylindrical.

56. A method of manufacturing an intravascular implant loading assembly using an elongate pusher member, a friction pad, a proximal protective device configured for alternately having a radially expanded configuration and a radially collapsed configuration, an introducer sheath, and an intravascular implant configured for alternately having a radially expanded configuration and a radially collapsed configuration, the method comprising: threading an elongate pusher member through an axial lumen of the friction pad and an axial lumen of the proximal protective device;axially affixing the friction pad and the proximal protective device to the pusher member to form a pusher member assembly; disposing the friction pad within a central lumen at the proximal end of an intravascular implant while the intravascular implant is in the radially expanded configuration; disposing the proximal protective device over the proximal end of the intravascular implant while the proximal protective device is in the radially expanded configuration, thereby forming a concentric arrangement with the intravascular implant and the pusher member assembly; and loading the intravascular implant into an inner sheath lumen of the introducer sheath, wherein the inner sheath lumen radially constrains the proximal protective device and intravascular implant into the respective radially collapsed configurations.

57. The method of claim 56, wherein the intravascular implant is proximally loaded into the inner sheath lumen, such that the proximal protective device slidably bears against the inner sheath lumen.

58. The method of claim 56, wherein the intravascular implant is one of a stent, a stent graft, a flow-diverter, a vaso-occlusive device, and a vena cava filter.

59. The method of claim 56, wherein axially affixing the friction pad to the pusher member comprises affixing a proximal bumper to the pusher member proximal to the friction pad, and affixing a distal bumper to the pusher member distal to the friction pad.

60. The method of claim 56, wherein the pusher member is a delivery wire.61 . The method of claim 56, further comprising: threading the elongate pusher member through an axial lumen of a distal protective device having a radially expanded configuration and a radially collapsed configuration; axially affixing the distal protective device to the elongate pusher member; anddisposing the distal protective device over the distal end of the intravascular implant while the distal protective device is in the radially expanded configuration, thereby adding the distal protective device to the concentric arrangement.

62. The method of claim 56, wherein the friction pad and the proximal protective device axially overlap, such that the proximal end of the intravascular implant is sandwiched between, and thus frictionally engaged by, the friction pad and the proximal protective device in the concentric arrangement.

63. The method of claim 56, wherein the proximal protective device is selfexpanding.

64. The method of claim 56, wherein the friction pad and the proximal protective device form a monolithic structure.

65. The method of claim 56, wherein the proximal protective device comprises a base proximal to the friction pad, the base having a profile greater than a profile of the friction pad, such that a ledge having a distal face is formed between the base and the friction pad.

66. The method of claim 56, wherein the proximal protective device comprises a plurality of arms configured for being cantilevered toward the friction pad when the intravascular implant is loaded into the inner sheath lumen, thereby frictionally engaging the proximal end of the intravascular implant against the friction pad.

67. The method of claim 56, wherein the friction pad has a durometer greater than 35D68. The method of claim 56, wherein the friction pad has a durometer in the range of 70D-85D.

69. The method of claim 56, wherein the friction pad is cylindrical.

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