Implant delivery assembly with distal protection features

Abstract

A delivery system for deploying a medical implant includes an elongated delivery wire assembly slidably disposed within a delivery catheter lumen, the delivery wire assembly having an implant loading region configured to place an implant when the delivery wire assembly is confined within the delivery catheter lumen and the implant is in a compressed delivery configuration. The delivery wire assembly also includes a distal end protection feature of the implant having a central portion connected distal to the delivery wire assembly at the implant loading region and a peripheral portion extending proximally from the central portion. When the delivery wire assembly, the implant, and the distal end protection feature are confined within the delivery catheter lumen, the peripheral portion at least partially covers the distal end portion of the implant, wherein the peripheral portion remains proximally extending when the implant is in an expanded configuration after being released from the delivery catheter lumen.

Description

[0001] field

[0002] The currently disclosed inventions generally relate to minimally invasive components for delivering medical implants. More specifically, this disclosure relates to delivery components for delivering medical implants (such as tubular stents or shunts) to a target implantation site in a patient's vascular system.

[0003] background

[0004] The use of endovascular implants (such as stents, stent grafts, shunts, aneurysm occlusion devices, and vena cava filters) has become an effective treatment for many types of vascular diseases. Generally, a suitable endovascular implantable device is inserted into the patient's vascular system and guided through the vascular system to the target implantation site using a delivery system (such as a catheter with a delivery lumen). Using currently available delivery devices, it is possible to access virtually any target site in the patient's vascular system, including the coronary, cerebral, and peripheral vascular systems.

[0005] Minimally invasive delivery devices include a catheter percutaneously introduced over a guidewire into a patient's vascular system, wherein the open distal end of the catheter is navigated to the target implantation site using known techniques. The medical implant is then deployed in a compressed (i.e., reduced diameter) delivery configuration through the delivery lumen of the catheter and subsequently introduced into the vascular lumen through the distal opening of the catheter. For example, self-expanding implants (such as stents) are delivered in an elastically compressed state while confined within the delivery lumen of a tubular catheter, and then elastically expand once deployed from the open distal end of the catheter and engaged with the vascular wall. The expanded and enlarged stent supports and reinforces the vascular wall, thereby maintaining the vessel in an open and unobstructed state.

[0006] Medical implants can come in a variety of sizes and shapes. For example, stents and some shunts, when deployed within a patient's vascular system, typically present an expanded, essentially tubular configuration. Furthermore, medical implants can be made from a variety of materials, including polymers (e.g., non-biodegradable and biodegradable plastics) and metals. Medical implants can be made from shape memory or hyperelastic materials, such as shape memory metals (e.g., shape memory nitinol) and polymers (e.g., polyurethane). Such shape memory implants can be induced (e.g., by temperature, an electric or magnetic field, or light) to take on a shape (e.g., a radially expanding shape) after delivery to the treatment site. Hyperelastic embolic materials, such as hyperelastic nitinol, take on a specific shape after delivery without requiring inducing stimulation. Other commonly used materials include stainless steel, platinum, and Elgiloy nonmagnetic alloys. Drug delivery implants can carry bioactive agents or therapeutic agents, and / or the surface of the device can be coated with bioactive agents or therapeutic agents. Commonly used medical implants (such as stents, stent grafts, shunts) can be composed of multiple filaments (e.g., wires) that are braided or woven into a predetermined (e.g., tubular) shape, or can be made from laser-cut tubes.

[0007] Known delivery systems may include retainer sleeves for controlled release or covers for protecting the implant tip during deployment, as illustrated and described (by example) in U.S. Patent Nos. 6,478,814, 6,830,575, and 8,591,566. Such sleeves / covers may include winged or separate components, which can be more challenging to manufacture and may increase resistance or friction exerted by the device components when pushed through the delivery catheter, negatively impacting the overall performance of the delivery system.

[0008] Therefore, there has been a need for an implant delivery system that helps protect the implant while avoiding or minimizing the increase in resistance or friction as it passes through the delivery conduit.

[0009] Overview

[0010] In one embodiment of the disclosed invention, a delivery system is provided for deploying an implant at a target site within a mammalian vascular system, the implant having a compression delivery configuration and a deployment configuration, wherein the delivery system includes an elongated delivery wire assembly at least partially disposed within the lumen of a delivery catheter, the delivery wire assembly being translatable relative to the delivery catheter, and having an implant loading region configured to place the implant when a distal portion of the delivery wire assembly including the implant is confined within the lumen of the delivery catheter and the implant is in the compression delivery configuration. The delivery wire assembly includes a distal protection feature for the implant, which includes a central portion connected distal to the implant loading region to the delivery wire assembly, and a peripheral portion extending proximally from the central portion. When the distal portion of the delivery wire assembly, including the implant and the distal protection feature, is confined within the lumen of the delivery catheter, the peripheral portion at least partially covers the distal end portion of the implant. The peripheral portion of the distal protection feature remains proximally extending when the implant is released from the lumen of the delivery catheter and is in an extended configuration and no longer covered by the distal protection feature.

[0011] In various embodiments, the peripheral portion of the distal protective feature of the implant may include a plurality of circumferentially spaced petal-shaped portions extending from the central portion. As a non-limiting example, in one embodiment, the peripheral portion of the distal protective feature of the implant consists of three petal-shaped portions that are circumferentially spaced substantially uniformly around the delivery wire assembly.

[0012] In one embodiment, when the distal portion of the delivery wire assembly, which includes the implant and the distal protection feature of the implant, is confined within the lumen of the delivery catheter, the distal protection feature of the implant covers approximately 20 percent of the total length of the implant.

[0013] In another embodiment, when the distal portion of the delivery wire assembly, which includes the implant and the distal protection feature of the implant, is confined within the lumen of the delivery catheter, the distal protection feature of the implant covers approximately 10% to approximately 20% of the total length of the implant.

[0014] In yet another embodiment, when the distal portion of the delivery wire assembly, which includes the implant and the distal protection feature of the implant, is confined within the lumen of the delivery catheter, the distal protection feature of the implant covers approximately five percent to approximately ten percent of the total length of the implant.

[0015] In another embodiment, when the distal portion of the delivery wire assembly, which includes the implant and the distal protection feature of the implant, is confined within the lumen of the delivery catheter, the implant protection feature covers approximately five percent or less of the total length of the implant.

[0016] The central portion of the distal protection feature of the implant can be fixedly attached to the delivery wire assembly in a manner that prevents the distal protection feature from rotating relative to the delivery wire assembly. In an alternative embodiment, the central portion of the distal protection feature of the implant is attached to the delivery wire assembly in a manner that allows the distal protection feature to rotate relative to the delivery wire assembly.

[0017] Other and additional aspects and features of the embodiments of the invention disclosed herein will become apparent from the following detailed description, taking into account the accompanying drawings. Brief description of the attached diagram

[0019] Figure 1 This is a side view of an implant delivery system constructed according to one embodiment of the disclosed invention.

[0020] Figures 2A-2E yes Figure 1 Partial sectional side view, perspective view and exploded view of the delivery wire assembly of the implant delivery system, showing in more detail the part of the system including the distal protection features of the implant.

[0021] Figure 3 yes Figure 2E An end view of the distal protective feature of the implant shown, wherein the distal protective feature of the implant is fully open;

[0022] Figures 4A-4D This is a cross-sectional view, side view, and perspective view of the distal protection features of the implant depicted when the delivery wire assembly is loaded into the delivery catheter 120, according to an embodiment of the disclosed invention.

[0023] Figures 5A-5D Is using Figures 1-4D Side and perspective views of the distal protective features of the implant depicted during the delivery and deployment of the implant at the target site in the vascular system using an implant delivery system.

[0024] Detailed description of the illustrated embodiments

[0025] For the terms defined below, these definitions shall apply unless otherwise specified in the claims or in other parts of this specification.

[0026] Whether explicitly stated otherwise, all numerical values ​​herein are assumed to be modified by the terms “substantially” or “approximately”. The terms “substantially” and “approximately” refer to a range of numbers that a person skilled in the art would consider equivalent to the stated parameter, structure, or value (i.e., having the same function or result). In many cases, the terms “approximately” and “substantially” include numbers rounded to the nearest significant figure. Numerical ranges expressed by endpoints include all numbers within that range (e.g., 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

[0027] As used in this specification and the appended claims, unless otherwise expressly specified, the singular forms “a,” “an,” and “the” include plural indicators. As used in this specification and the appended claims, unless otherwise expressly specified, the term “or” is generally used in the sense of including “and / or.”

[0028] As used in this specification and the appended claims, the terms “proximal” and “proximally” (etc.) when used to describe relative position mean that the position or orientation of the structure or the movement of the implant delivery system is toward the outside of the patient; the terms “distal” and “distally” (etc.) when used to describe relative position mean that the position or orientation of the structure or the movement of the implant delivery system extends most deeply into the patient.

[0029] Various embodiments of the disclosed invention are described below with reference to the accompanying drawings. The drawings are not necessarily drawn to scale; for clarity, the relative proportions of selected elements may be enlarged, and in all drawings, elements of similar structure or function are represented by the same reference numerals. It should also be understood that the drawings are intended only to aid in the description of the embodiments and are not intended as an exhaustive description of the disclosed invention or as a limitation on the scope of the disclosed invention, which is defined only by the appended claims and their equivalents.

[0030] Furthermore, the various illustrated embodiments of the disclosed invention need not have all the depicted features, and the features, aspects, or advantages described in connection with a particular embodiment are not necessarily limited to that embodiment, but may be practiced in other embodiments, even if not illustrated in this way.

[0031] Figure 1An implant delivery system 100 constructed according to one embodiment of the disclosed invention is illustrated. The implant delivery system 100 generally includes an elongated tubular delivery catheter 120 having a proximal end portion 130, a distal end portion 160, and an inner lumen 125 extending therebetween, wherein the inner lumen 125 communicates with the respective open proximal and distal ends of the delivery catheter 120. The delivery catheter 120 is coaxially disposed within and movable relative to an outer sheath 180, which assists in positioning the distal end portion 160 of the delivery catheter 120 within a target portion of the vascular system. The proximal end portion 130 of the delivery catheter 120 includes a fluid port 150 for introducing fluid into the inner lumen 125 (this fluid port is located away from a proximal opening in the outer sheath 180 through which the delivery catheter 120 is inserted). The fluid delivery port 150 is retained outside the patient so that a physician / operator can access it when the implant delivery system 100 is inserted into the patient's vascular system. The distal portion 160 of the delivery catheter 120 is sized and designed to access remote locations within the vascular system, such as those within the neurovascular system. It may also have a smaller diameter (or profile) than the proximal portion 130.

[0032] The implant delivery system 100 also includes an implant delivery wire assembly 300 (described below in conjunction with...) Figures 2A-2E (Described in more detail), which includes a core wire 350 that is pushed through the lumen 125 of the delivery catheter for implanting an implant 200 supported on the distal end portion of the core wire 350. Figure 1 (Not shown in the image) is delivered to the target site in the patient's vascular system. For example... Figure 1 As depicted, the core wire 350 has been inserted through the proximal end opening of the delivery conduit 120 and pushed through the delivery lumen 125 such that a non-invasive distal end portion (e.g., a soft coil member) 380 attached to the distal end of the core wire 350 extends out of the distal end opening of the delivery conduit 120.

[0033] The outer sheath 180 of the implant delivery system 100 can be introduced over a previously introduced guidewire (not shown) (referred to as an over-the-wire configuration), or alternatively, in a “quick-change” configuration, where the guidewire extends only from the guidewire port (not shown) through the distal portion of the outer sheath 180, as is known. The delivery catheter 120 is then introduced through the outer sheath, either via the guidewire or otherwise, as is also known. The outer sheath 180 includes a radiopaque marker 355 adjacent to the open distal end of the sheath to aid in its positioning at the target location of the vascular system.

[0034] The delivery catheter 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. In some cases, the proximal portion 130 may include a reinforcing layer, such as a braided or coiled layer, to enhance maneuverability. The delivery catheter 120 may include one or more transition regions between the proximal portion 130 and the distal portion 160. The outer diameter of the distal end portion 160 may be smaller than that of the proximal portion 130 to reduce the profile of the distal end portion 160 and facilitate navigation of the distal end portion 160, which extends from the distal opening of the outer sheath 180, in a tortuous vascular system. The proximal end portion 130 may be formed of a stiffer material than the distal portion 160 of the delivery catheter 120, so that the proximal portion 130 has sufficient maneuverability to advance through the patient's vascular system, while the distal portion 160 may be formed of a softer material, so that the distal portion 160 remains flexible and easier to move on the guidewire to approach remote locations in tortuous areas of the vascular system. Figure 2A The best-looking, gradually narrowing radiopaque marker 455 and the non-invasive end 457 are respectively positioned near the distal end opening 452 of the delivery catheter 120.

[0035] refer to Figures 2A-2E Implant 200 may be a stent, shunt, or other type of vascular system implant carried on the distal portion of core wire 350. Implant 200 may include various biocompatible materials, such as stainless steel, Elgiloy nonmagnetic alloys, nickel, titanium, nitinol, shape memory polymers, or combinations thereof, and may be constructed using known techniques, such as by etching or cutting patterns from tubes or sheets of stent material, or by braiding / woven one or more filaments or strips into desired shapes and patterns. Implant 200 may include other components welded, bonded, or otherwise joined together, and may optionally include non-porous, impermeable biocompatible materials, coverings, etc.

[0036] As in Figure 2D As best viewed, the implant 200 is generally tubular and has a proximal portion 220, a distal portion 240, and an internal lumen 260 extending therebetween. It is noteworthy that the implant 200... Figures 2A-2E The implant 200 is shown in a compressed, elongated delivery configuration, disposed (i.e., radially confined) within the lumen 125 of the delivery catheter 120. When unfolded from the distal end opening of the delivery catheter 120 (i.e., no longer radially confined within the delivery catheter 120), the implant 200 is preferably biased to self-expand radially outward into an extended unfolded configuration.

[0037] like Figures 2A-2BAs shown, the core wire 350 of the delivery wire assembly 300 is coaxially disposed within the lumen 125 of the delivery catheter, and the implant 200 is coaxially disposed around the core wire 350 and also constrained within the lumen 125 of the delivery catheter. Specifically, the core wire 350 is axially movable relative to the delivery catheter 120, and the delivery wire assembly 300 is configured to engage the implant 200 when the core wire 350 is axially translated through the lumen 125 of the delivery catheter for delivery of the implant 200 to a target implantation site in the vascular system. The docking between the delivery wire assembly 300 and the implant 200 will be described in further detail below.

[0038] A radiopaque marker 360 (e.g., a laser-etched, radiopaque strip, or any other suitable marker) is preferably positioned along the distal portion of the mandrel 350 to aid in positioning the mandrel 350 and implant 200 relative to the delivery catheter 120. In the illustrated embodiment, a coil 357 is disposed around the mandrel 350 to provide structural support only proximally to the implant 200. The radiopaque marker strip 360 is disposed on the distal portion 358 of the coil 357 to indicate the position of the proximal end portion 220 of the implant 200. An epoxy adhesive portion 376 is used to attach the marker 360 to the mandrel 350.

[0039] like Figures 2B-2C As shown, a re-sheathing pad 370 is disposed distal to the core wire 350 of the coil 357, and an implant re-sheathing bumper 375 is attached to the core wire 350 at the distal end of the re-sheathing pad 370. An epoxy adhesive portion 376 is used to attach the re-sheathing bumper to the core wire 350. The area on the core wire 350 where the implant 200 is loaded is referred to herein as the implant loading area. Specifically, the proximal portion 220 of the implant 200 is disposed on the respective re-sheathing pad 370 and re-sheathing bumper 375, and the distal end of the distal portion 240 of the implant 200 is protected by a distal protection feature 500. Figure 2E The distal protection feature 500 is attached to the core wire 350 and secured between the corresponding proximal locking member 550 and distal locking member 550. In most figures, only the distal locking member 550 is shown because the proximal locking member 550 is obscured by the distal protection feature 500 of the implant. However, the proximal locking member... Figure 5C As shown below, the non-invasive distal end 380 (e.g., a soft coil member) is attached to the core wire near the distal locking member 550. Figure 2B , Figure 2E ).

[0040] Figure 3The illustration shows a distal implant protection feature 500 of a delivery filament assembly 300 according to one embodiment of the disclosed invention. The distal implant protection feature 500 is preferably composed of a biocompatible material, such as ePTFE. In one embodiment, the distal implant protection feature 500 is made of a thin, substantially uniform ePTFE layer having a thickness of approximately 0.0152 mm (0.0006 inches) and a length of approximately 0.44 mm (0.0173 inches). Figure 3 As shown, the distal protection feature 500 of the implant includes a peripheral portion in the form of three circumferentially spaced petal-shaped members (or "petals") 520, which meet at the central portion 511 attached to the core wire 350. Figure 2E ).like Figure 4A As shown (as described below), when the distal protective feature 500 of the implant is not confined within the delivery conduit 120, the peripheral petals 520 extend generally radially outward from the central portion 511 and point proximally.

[0041] In the illustrated embodiment, the distal protection feature 500 of the implant is securely attached to the mandrel 350 by a locking member 550, such that the distal protection feature of the implant does not rotate relative to the mandrel 350. In an alternative embodiment, the distal protection feature 500 of the implant may be attached to a collar (not shown), which is still secured in a relative longitudinal position to the mandrel 350 by the locking member 550, allowing the collar, and thus the distal protection feature 550 of the implant, to rotate relative to the mandrel 350 and the locking member 550.

[0042] Figures 4A-4D The illustration shows an embodiment of the disclosed invention in which the front portion of the delivery filament assembly 300 is loaded into the delivery conduit 120. Figure 4A The distal end portion of the delivery wire assembly 300, including the distal implant protection feature 500 and the implant 200, is depicted just before being loaded into the delivery catheter 120, wherein the peripheral petals 520 of the distal implant protection feature 500 are shown extending generally proximally in a radially unrestricted configuration. The implant 200 is coaxially disposed around a core wire 350 (not shown) and held in a radially restricted delivery configuration by a tubular loading member 390, the distal end portion 240 of the implant 200 being at least partially exposed outside the distal end opening of the loading member 390.

[0043] The distal end portion of the delivery wire assembly 300, including the distal protection feature 500 of the implant and the compression implant 200, either advances into the delivery conduit 120, or the delivery conduit 120 advances onto the distal portion of the delivery wire assembly 300, or both the delivery wire assembly 300 and the delivery conduit 120 advance a portion, thereby radially compressing the peripheral petals 520 of the distal protection feature 500 onto the distal portion 240 of the implant 200, such as... Figures 4B-4C As shown. Once the delivery conduit 120 is positioned on the corresponding distal implant protection feature 500 and loading member 390, the loading member 390 is retracted, while the implant 200 remains in a compressed delivery configuration within the lumen 125 of the delivery conduit 120, and the peripheral petals 520 of the distal implant protection feature 500 remain compressed against the distal portion 240 of the implant 200, and at least partially cover the distal portion 240 of the implant 200. Figure 4D ).

[0044] Although the disclosed invention is not limited thereto, the illustrated "three-petal" configuration of the distal protection feature 500 of the implant is configured to minimize the amount of material covering the distal end of the distal portion 240 of the implant 200, thereby reducing and minimizing the resistance or friction exerted by the implant on the inner wall of the delivery catheter 120 as the implant 200 is pushed through the lumen 125. Specifically, the inventors of the disclosed invention have found that by employing the depicted three-petal configuration of the distal protection feature 500 of the implant, the coefficient of friction between the implant 200 and the inner wall of the delivery catheter 120 is in the range of approximately 0.01 to approximately 0.04 when there is relative movement between the core wire 350 and the delivery catheter 120.

[0045] In various embodiments, when the distal portion of the delivery wire assembly 300, including the implant 200 and the distal protection feature 500, is confined within the lumen 125 of the delivery catheter, the size and configuration of the distal protection feature 550 can be designed to cover varying amounts of the distal end portion 240 of the implant 200. By way of non-limiting example, in one embodiment, when the distal portion of the delivery wire assembly 300, including the implant 200 and the distal protection feature 500, is confined within the lumen 125 of the delivery catheter, the size and configuration of the distal protection feature 500 is designed to cover approximately twenty percent of the total length of the implant 200. In another embodiment, when the distal portion of the delivery wire assembly 300, including the implant 200 and the distal protection feature 500, is confined within the lumen 125 of the delivery catheter, the size and configuration of the distal protection feature 500 is designed to cover between approximately ten percent and approximately twenty percent of the total length of the implant. In yet another embodiment, when the distal portion of the delivery wire assembly 300, including the implant 200 and the distal protection feature 500, is confined within the lumen 125 of the delivery catheter, the size and configuration of the distal protection feature 500 are designed to cover approximately five percent to approximately ten percent of the total length of the implant 200. In yet another embodiment, when the distal portion of the delivery wire assembly 300, including the implant 200 and the distal protection feature 500, is confined within the lumen 125 of the delivery catheter, the size and configuration of the distal protection feature 500 are designed to cover approximately five percent or less of the total length of the implant 200.

[0046] Figures 5A-5D The illustration shows the distal protective feature 500 of the implant during delivery of the implant 200 to a target site (not shown) in the vascular system and during the deployment of the implant 200 at that site.

[0047] Figure 5A Depicting the core filament 350 (in Figure 5A The distal end portion of the delivery wire assembly 300 (not shown) is pushed through the lumen 125 of the delivery catheter. The implant 200 and the distal implant protection feature 500 are shown in a compressed delivery configuration, confined within the lumen 125 of the delivery catheter, with the peripheral petals 520 of the distal implant protection feature 500 covering and protecting the distal portion 240 of the implant 200.

[0048] Once the distal portion of the delivery assembly 300 is near the target implantation site, the delivery catheter 120 is either retracted proximally relative to the mandrel 350, or the mandrel 350 is pushed distally relative to the delivery catheter 120, or both in part, thereby exposing the distal protection feature 500 and the implant 200 beyond the distal end opening 452 of the delivery catheter 120, allowing the implant 200, no longer radially restricted, to radially extend from the distal end portion 240 to an extended configuration, such as... Figures 5B-5D As shown. It is worth noting that when the distal end portion 240 of the implant 200 is in an extended configuration and is no longer covered by the distal protection feature 500 of the implant, the peripheral petals 520 of the distal protection feature 500 of the implant remain extended generally in the proximal direction (i.e., in the "delivery configuration").

[0049] The distal protection feature 500 of the implant is preferably configured to apply a negligible or insignificant force on the distal portion 240 of the implant 200 as the implant 200 expands. In some embodiments, the distal protection feature 500 may expand radially outward when no longer radially confined by the delivery conduit 120. In any embodiment, when the distal protection feature 500 maintains its delivery configuration or expands outward when no longer confined by the delivery conduit 120, the peripheral petals 520 are configured to extend proximally and / or face proximally, i.e., the individual petals 520 preferably do not evert as the implant 200 expands.

[0050] After the implant 200 is deployed at the target site, the delivery wire assembly 300 is retracted into the delivery catheter (not shown), and the delivery system 100 is withdrawn from the body, leaving the expanded implant 200 at the target site. Notably, the core wire 350 and the distal implant protection feature 500 are pulled through the lumen 260 of the implant 200 and back into the lumen 125 of the delivery catheter without interfering with the deployed expanded implant 200. This is due to the "proximal-facing" configuration of the distal implant protection feature 500 and its relatively small size relative to the expanded implant 200. Figure 5D-5D' As shown. Figure 5D' yes Figure 5D An enlarged view of the cross-section shown is provided to better illustrate that the distal protection feature 500 of the implant essentially retains its delivery configuration even when the delivery conduit 120 no longer restricts the distal protection feature 500 of the implant.

[0051] Although specific embodiments have been shown and described herein, it will be understood by those skilled in the art that these embodiments are not intended to limit the disclosed invention, and it will be apparent to those skilled in the art that various changes, substitutions, and modifications (e.g., the dimensions of various components, combinations of components) can be made without departing from the scope of the disclosed invention, the scope of which is defined only by the appended claims and their equivalents. Accordingly, the specification and drawings should be viewed in an illustrative rather than a restrictive sense. The various embodiments shown and described herein are intended to cover substitutions, modifications, and equivalents of the disclosed invention that may be included within the scope of the appended claims.

Claims

1. A delivery system for deploying an implant at a target site within a mammalian vascular system, the implant having a compression delivery configuration and an expansion deployment configuration, the delivery system comprising: Delivery conduit, the delivery conduit having an inner lumen; An elongated delivery wire assembly, at least partially disposed within the lumen of the delivery catheter, the delivery wire assembly being translatable relative to the delivery catheter, and having an implant loading region configured to place the implant when a distal portion of the delivery wire assembly including the implant is confined within the lumen of the delivery catheter and the implant is in the compression delivery configuration; as well as The distal protection feature of the implant includes a central portion and a peripheral portion, the central portion being coupled distally to the delivery wire assembly in the implant loading region, and the peripheral portion extending proximally from the central portion to at least partially cover the distal end portion of the implant when the distal portion of the delivery wire assembly, including the implant and the distal protection feature, is confined within the lumen of the delivery catheter. When the peripheral portion of the distal protective feature of the implant is no longer restricted by the delivery catheter, the peripheral portion of the distal protective feature of the implant is allowed to expand radially. Wherein, when the implant has been released from the lumen of the delivery catheter and is in the extended deployment configuration and is no longer covered by the peripheral portion of the distal protective feature of the implant, the peripheral portion of the distal protective feature of the implant remains extended in the proximal direction. The peripheral portion of the distal protective feature of the implant includes a plurality of circumferentially spaced petal-shaped portions extending from the central portion in an overlapping manner, such that no part of the distally facing circumferential edge of the implant is exposed. The distal protection feature of the implant is configured to be withdrawn into the delivery catheter without everting from the proximal direction to the distal direction.

2. The conveying system according to claim 1, wherein, The peripheral portion of the distal protective feature of the implant consists of three petal-shaped parts.

3. The conveying system according to claim 1, wherein, The petal-shaped portions are spaced out circumferentially and substantially evenly around the conveyor wire assembly.

4. The conveying system according to any one of claims 1-3, wherein, When the distal portion of the delivery wire assembly, which includes the implant and the distal protection feature of the implant, is confined within the lumen of the delivery catheter, the distal protection feature of the implant covers five percent or less of the total length of the implant.

5. The conveying system according to any one of claims 1-3, wherein, The central portion of the distal protective feature of the implant is fixedly attached to the delivery wire assembly in such a manner that the distal protective feature of the implant cannot rotate relative to the delivery wire assembly.

6. The conveying system according to any one of claims 1-3, wherein, The central portion of the distal protective feature of the implant is attached to the delivery wire assembly in such a manner that the distal protective feature of the implant can rotate relative to the delivery wire assembly.

7. The conveying system according to any one of claims 1-3, wherein, The distal protection feature of the implant is configured to apply a negligible or insignificant force to the distal end portion of the implant as the implant extends from the compression delivery configuration to the extension deployment configuration.

8. The conveying system according to any one of claims 1-3, wherein, The distal protective feature of the implant essentially maintains its delivery configuration after it has expanded radially and is no longer restricted by the delivery conduit.

9. The conveying system according to any one of claims 1-3, wherein, The distal protection feature of the implant is configured not to evert in the distal direction when the implant expands.

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