U.S. patent application number 17/824768 was filed with the patent office on 2022-09-08 for implant delivery assembly with distal protection feature.
This patent application is currently assigned to STRYKER CORPORATION. The applicant listed for this patent is STRYKER CORPORATION, STRYKER EUROPEAN OPERATIONS LIMITED. Invention is credited to Miranda Ray, Vincent Yeh.
Application Number | 20220280277 17/824768 |
Document ID | / |
Family ID | 1000006359138 |
Filed Date | 2022-09-08 |
United States Patent
Application |
20220280277 |
Kind Code |
A1 |
Yeh; Vincent ; et
al. |
September 8, 2022 |
IMPLANT DELIVERY ASSEMBLY WITH DISTAL PROTECTION FEATURE
Abstract
A delivery system for deploying a medical implant includes an
elongate delivery wire assembly slidably disposed within a delivery
catheter lumen, the delivery wire assembly having an implant
loading region configured for seating the implant when the delivery
wire assembly is constrained within the delivery catheter lumen and
the implant is in a compressed delivery configuration, the delivery
wire assembly further including an implant distal protection
feature having a central portion coupled to the delivery wire
assembly distal of the implant loading region, and a peripheral
portion extending proximally from the central portion to at least
partially cover a distal end portion of the implant when the
delivery wire assembly, implant and implant distal protection
feature are constrained within the delivery catheter lumen, wherein
the peripheral portion remains extending in the proximal direction
when the implant assumes an expanded configuration after being
released from the delivery catheter lumen.
Inventors: |
Yeh; Vincent; (Kalamazoo,
MI) ; Ray; Miranda; (Kalamazoo, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
STRYKER CORPORATION
STRYKER EUROPEAN OPERATIONS LIMITED |
Kalamazoo
Carrightwohill |
MI |
US
IE |
|
|
Assignee: |
STRYKER CORPORATION
Kalamazoo
MI
STRYKER EUROPEAN OPERATIONS LIMITED
Carrigtwohill
|
Family ID: |
1000006359138 |
Appl. No.: |
17/824768 |
Filed: |
May 25, 2022 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
16535302 |
Aug 8, 2019 |
11344400 |
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17824768 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61F 2230/005 20130101;
A61F 2/95 20130101; A61F 2/013 20130101 |
International
Class: |
A61F 2/01 20060101
A61F002/01; A61F 2/95 20060101 A61F002/95 |
Claims
1. A delivery system for deploying an intravascular implant, the
implant having a compressed delivery configuration and an expanded
deployed configuration, the delivery system comprising: a tubular
member having a lumen; an elongate delivery assembly partially
disposed within the tubular member lumen-and slidably translatable
relative to the tubular member, wherein the elongate delivery
assembly comprises an implant loading region configured for the
implant to be disposed on when a distal portion of the delivery
assembly including the implant is constrained within the tubular
member lumen and the implant is in the compressed delivery
configuration; and an implant distal protection element comprising
a central portion coupled to the elongate delivery assembly distal
of the implant loading region, and a peripheral portion extending
proximally from the central portion such that the peripheral
portion partially covers a distal end portion of the implant when
the distal portion of the elongate delivery assembly including the
implant and implant distal protection element is constrained within
the tubular member lumen, wherein the peripheral portion of the
implant distal protection element is configured to expand and not
evert from a proximally facing direction to a distally facing
direction when the peripheral portion of the implant distal
protection element is no longer constrained by the tubular
member.
2. The delivery system of claim 1, wherein the peripheral portion
of the implant distal protection element comprises a plurality of
circumferentially spaced petal-like portions that extend from the
central portion.
3. The delivery system of claim 2, wherein the peripheral portion
of the implant distal protection element consists of three
petal-like portions.
4. The delivery system of claim 1, wherein the petal-like portions
are substantially evenly circumferentially spaced around the
elongate delivery assembly.
5. The delivery system of claim 1, wherein the elongate delivery
assembly comprises a wire, coil or strand.
6. The delivery system of claim 1, wherein the tubular member
comprises a delivery catheter, micro-catheter or cannula.
7. The delivery system of claim 1, wherein the peripheral portion
of the implant distal protection element remains extending in the
proximally facing direction when the implant assumes the expanded
deployed configuration after the implant has been released from the
tubular member lumen and is no longer covered by the peripheral
portion of the implant distal protection element.
8. The delivery system of claim 1, wherein the implant distal
protection element covers about twenty percent of a total length of
the implant when the distal portion of the elongate delivery
assembly including the implant and implant distal protection
element is constrained within the tubular member lumen.
9. The delivery system of claim 1, wherein the implant distal
protection element covers between about ten percent and about
twenty percent of a total length of the implant when the distal
portion of the elongate delivery assembly including the implant and
implant distal protection element is constrained within the tubular
member lumen.
10. The delivery system of claim 1, wherein the implant distal
protection element covers between about five percent and about ten
percent of a total length of the implant when the distal portion of
the elongate delivery assembly including the implant and implant
distal protection element is constrained within the tubular member
lumen.
11. The delivery system of claim 1, wherein the implant distal
protection element covers about five percent or less of a total
length of the implant when the distal portion of the elongate
delivery wire assembly including the implant and implant distal
protection element is constrained within the tubular member
lumen.
12. The delivery system of claim 1, wherein the central portion of
the implant distal protection element is fixedly attached to the
elongate delivery assembly in a manner such that the implant distal
protection element is not rotatable relative to the elongate
delivery assembly.
13. The delivery system of claim 1, wherein the central portion of
the implant distal protection element is attached to the elongate
delivery assembly in a manner such that the implant distal
protection element is rotatable relative to the elongate delivery
assembly.
14. The delivery system of claim 1, wherein the implant distal
protection element is configured to exert negligible or
insignificant forces over the distal portion of the implant as the
implant expands from the compressed delivery configuration to the
expanded deployed configuration.
15. The delivery system of claim 1, wherein the implant distal
protection element substantially retains a compressed delivery
configuration after the implant distal protection element radially
expands and is no longer constrained by the tubular member.
16. The delivery system of claim 1, wherein the implant distal
protection element is configured to not evert to the distally
facing direction as the implant expands.
17. The delivery system of claim 1, wherein the implant distal
protection element is configured to be withdrawn back into the
tubular member without everting from the proximally facing
direction to the distally facing direction.
18. The delivery system of claim 1, wherein the implant distal
protection element comprises a biocompatible material having a
thickness of about 0.0006'', a length of about 0.0173''.
19. The delivery system of claim 18, wherein the peripheral portion
of the implant distal protection element consists of three
petal-like portions that are circumferentially spaced around and
extend from the central portion.
Description
RELATED APPLICATION DATA
[0001] The present application is a continuation of U.S. patent
application Ser. No. 16/535,302, filed Aug. 8, 2019. The foregoing
application is hereby incorporated by reference into the present
application in its entirety.
FIELD
[0002] The presently disclosed inventions relate generally to
minimally invasive assemblies used for delivering medical implants.
More particularly, the present disclosure relates to delivery
assemblies for delivering medical implants, such as a tubular stent
or flow diverter, to a targeted implantation site in the
vasculature of a patient.
BACKGROUND
[0003] The use of intravascular implants, such as stents, stent
grafts, flow-diverters, aneurysm occlusive devices, vena cava
filters, etc., has become an effective method for treating many
types of vascular disease. In general, a suitable intravascular
implantable device is inserted into the vascular system of the
patient and navigated through the vasculature to a targeted
implantation site using a delivery system, such as a catheter
having a delivery lumen. Using currently available delivery
apparatus, virtually any target site in the patient's vascular
system may be accessed, including the coronary, cerebral, and
peripheral vasculature.
[0004] Minimally invasive delivery devices include catheters that
are percutaneously introduced into the patient's vasculature over a
guidewire, wherein an open distal end of the catheter is navigated
to a targeted implantation site using well-known techniques. A
medical implant is then deployed through a delivery lumen of the
catheter in a compressed (i.e., reduced diameter) delivery
configuration, and then introduced into a lumen of a blood vessel
through the distal end opening of the catheter. For example,
self-expanding implants, such as stents, are delivered in an
elastically compressed state while being confined within the
tubular catheter delivery lumen, and then elastically expand once
deployed out the open distal end of the catheter and into
engagement with the interior wall of the blood vessel. The expanded
and enlarged stent supports and reinforces the vessel wall, thereby
maintaining the vessel in an open and unobstructed condition.
[0005] Medical implants may have a variety of sizes and shapes. For
example, stents and some flow-diverters usually assume an expanded,
substantially tubular configuration when deployed within the
vasculature of a patient. Further, medical implants can be made
from a variety of materials, including polymers (e.g.,
nonbioerodable and bioerodable plastics) and metals. Medical
implants can be made from shape memory or superelastic 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, electrical or magnetic field or
light) to take on a shape (e.g., a radially expanded shape) after
delivery to a treatment site. Superelastic embolic materials, such
as superelastic Nitinol, take on a shape after delivery without the
need for an inductive stimulus. Other commonly used materials
include stainless steel, platinum and elgiloy. Drug delivery
implants can carry, and/or the surface of the device, can be coated
with bioactive or therapeutic agents. Commonly used medical
implants, such as stents, stent grafts, flow-diverters, may be
composed of a plurality of filaments (e.g., wires) that are braided
or woven into predetermined (e.g., tubular) shape, or may be made
out of laser cut tubes.
[0006] Known delivery systems may include retainer sleeves to
control release or covers to protect the ends of the implants
during deployment, which are illustrated and described (by way of
example) in U.S. Pat. Nos. 6,478,814, 6,830,575 and 8,591,566. Such
sleeves/covers include winged or separate members that may be more
challenging to manufacture and may increase resistive or frictional
forces imposed by the device assembly when being pushed through the
delivery catheter, negatively impacting the overall performance of
the delivery system.
[0007] Therefore, there is an ongoing need to provide an implant
delivery system for delivering self-expanding implants that
facilitates protection of the implant, while avoiding or minimizing
an increase in resistive or frictional forces through the delivery
catheter.
SUMMARY
[0008] In one embodiment of the disclosed inventions, a delivery
system is provided for deploying an implant at a target site within
a mammalian vasculature, the implant having a compressed delivery
configuration and an expanded deployed configuration, wherein the
delivery system includes an elongate 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
for seating the implant when a distal portion of the delivery wire
assembly including the implant is constrained within the delivery
catheter lumen and the implant is in the compressed delivery
configuration. The delivery wire assembly includes an implant
distal protection feature comprising a central portion coupled to
the delivery wire assembly distal of the implant loading region,
and a peripheral portion extending proximally from the central
portion to at least partially cover a distal end portion of the
implant when the distal portion of the delivery wire assembly,
including the implant and implant distal protection feature, is
constrained within the delivery catheter lumen, and wherein the
peripheral portion of the implant distal protection feature remains
extending in the proximal direction when the implant assumes the
expanded configuration after being released from the delivery
catheter lumen and is no longer covered by the implant distal
protection feature.
[0009] In various embodiments, the peripheral portion of the
implant distal protection feature may be comprised of a plurality
of circumferentially spaced petal-like portions that extend from
the central portion. By way of non-limiting example, in one
embodiment, the peripheral portion of the implant distal protection
feature consists of three petal-like portions that are
substantially evenly circumferentially spaced around the delivery
wire assembly.
[0010] In one embodiment, the implant distal protection feature
covers about twenty percent of a total length of the implant when
the distal portion of the delivery wire assembly including the
implant and implant distal protection feature is constrained within
the delivery catheter lumen.
[0011] In another embodiment, the implant distal protection feature
covers between about ten percent and about twenty percent of a
total length of the implant when the distal portion of the delivery
wire assembly including the implant and implant distal protection
feature is constrained within the delivery catheter lumen.
[0012] In yet another embodiment, the implant distal protection
feature covers between about five percent and about ten percent of
a total length of the implant when the distal portion of the
delivery wire assembly including the implant and implant distal
protection feature is constrained within the delivery catheter
lumen.
[0013] In still another embodiment, the implant protection member
covers about five percent or less of a total length of the implant
when the distal portion of the delivery wire assembly including the
implant and implant distal protection feature is constrained within
the delivery catheter lumen.
[0014] The central portion of the implant distal protection feature
may be fixedly attached to the delivery wire assembly in a manner
such that the implant distal protection feature is not rotatable
relative to the delivery wire assembly. In alternative embodiment,
the central portion of the implant distal protection feature is
attached to the delivery wire assembly in a manner such that the
implant distal protection feature is rotatable relative to the
delivery wire assembly.
[0015] Other and further aspects and features of embodiments of the
herein disclosed inventions will become apparent from the ensuing
detailed description in view of the accompanying figures.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is a side view of an implant delivery system
constructed according to one embodiment of the disclosed
inventions.
[0017] FIGS. 2A-E are partially cut-away side, perspective and
exploded views of a delivery wire assembly of the implant delivery
system of FIG. 1, showing portions of the system in greater detail
including an implant distal protection feature.
[0018] FIG. 3 is elevated end view of the implant distal protection
feature shown in FIG. 2E, wherein the implant distal protection
feature is fully opened;
[0019] FIGS. 4A-D are cut-away, side and perspective views of the
implant distal protection feature depicted as the delivery wire
assembly is loaded into the delivery catheter 120, according to one
embodiment of the disclosed inventions.
[0020] FIGS. 5A-D' are side and perspective views of the implant
distal protection feature depicted during delivery and deployment
of an implant at a targeted site in a vasculature using the implant
delivery system of FIGS. 1-4.
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
[0021] For the following defined terms, these definitions shall be
applied, unless a different definition is given in the claims or
elsewhere in this specification.
[0022] All numeric values are herein assumed to be modified by the
terms "substantially" or "about," whether or not explicitly
indicated. The terms "substantially" and "about" refer to a range
of numbers that one of skill in the art would consider equivalent
to the recited parameter, structure or value (i.e., having the same
function or result). In many instances, the terms "about" and
"substantially" include numbers that are rounded to the nearest
significant figure. The recitation of numerical ranges by endpoints
includes all numbers within that range (e.g., 1 to 5 includes 1,
1.5, 2, 2.75, 3, 3.80, 4, and 5).
[0023] As used in this specification and the appended claims, the
singular forms "a", "an", and "the" include plural referents unless
the content clearly dictates otherwise. As used in this
specification and the appended claims, the term "or" is generally
employed in its sense including "and/or" unless the content clearly
dictates otherwise.
[0024] As used in this specification and the appended claims, the
terms "proximal" and "proximally" (and the like) when used to
describe a relative position, the location or direction of a
structure or action of the implant delivery system that is towards
the outside of the patient's body; and the terms "distal" and
"distally" (and the like) when used to describe a relative
position, the location or direction of a structure or action of the
implant delivery system that is extended deepest into the patient's
body.
[0025] Various embodiments of the disclosed inventions are
described hereinafter with reference to the figures. The figures
are not necessarily drawn to scale, the relative scale of select
elements may have been exaggerated for clarity, and elements of
similar structures or functions are represented by like reference
numerals throughout the figures. It should also be understood that
the figures are only intended to facilitate the description of the
embodiments, and are not intended as an exhaustive description of
the disclosed inventions, or as a limitation on the scope thereof,
which is defined only by the appended claims and their
equivalents.
[0026] In addition, the respective illustrated embodiments of the
disclosed inventions need not have all of the depicted features,
and a feature, aspect or advantage described in conjunction with a
particular embodiment is not necessarily limited to that
embodiment, but can be practiced in other embodiments, even if not
so illustrated.
[0027] FIG. 1 illustrates an implant delivery system 100,
constructed according to the one embodiment of the disclosed
inventions. The implant delivery system 100 generally comprises an
elongate, tubular delivery catheter 120 having a proximal end
portion 130, a distal end portion 160, and a lumen 125 extending
there between, wherein the delivery catheter lumen 125 is in
communication with 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 that
is used to help position the distal end portion 160 of the delivery
catheter 120 within a target portion of the vasculature. The
proximal end portion 130 of the delivery catheter 120 includes a
fluid port 150 (distal to a proximal opening in the outer sheath
180 through which the delivery catheter 120 is inserted) used to
introduce fluids into the lumen 125. The fluid delivery port 150
remains outside of the patient's body so as to be accessible to the
physician/operator when the implant delivery system 100 is inserted
into a patient's vasculature. The distal portion 160 of the
delivery catheter 120 is sized and dimensioned to access remote
locations within the vasculature, such as, e.g., within the
neuro-vasculature. And may have a smaller diameter (or profile)
than the proximal portion 130.
[0028] The implant delivery system 100 further includes an implant
delivery wire assembly 300 (described below in greater detail in
conjunction with FIGS. 2A-E), including a core wire 350 that is
pushed through the delivery catheter lumen 125 for delivering an
implant 200 (not shown in FIG. 1) carried on a distal end portion
of the core wire 350 to a targeted site in a patient's vasculature.
As depicted in FIG. 1, the core wire 350 has been inserted through
the proximal end opening of the delivery catheter 120, and pushed
through the delivery lumen 125, such that an atraumatic distal tip
portion (e.g., a soft coil member) 380 attached to a distal end of
the core wire 350 is extending out a distal end opening of the
delivery catheter 120.
[0029] The outer sheath 180 of the implant delivery system 100 may
be introduced into the vasculature over a guidewire (not shown)
that has been previously introduced, known as an over-the-wire
configuration), or alternatively may be introduced in a
"rapid-exchange" configuration, where a guidewire extends through
only a distal portion of the outer sheath 180 from a guidewire port
(not shown), as is well-known. The delivery catheter 120 is then
introduced through the outer sheath, whether over the guidewire or
otherwise, again, as is well-known. The outer sheath 180 includes a
radiopaque marker 355 adjacent to an open distal end of the sheath
to assist with positioning thereof in a targeted location of the
vasculature.
[0030] 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 instances, the proximal portion 130
may include a reinforcement layer, such a braided layer or coiled
layer to enhance pushability. The delivery catheter 120 may include
one or more transition regions between the proximal portion 130 and
the distal portion 160. The distal end portion 160 may have an
outer diameter less than the outer diameter of the proximal portion
130 in order to reduce the profile of the distal end portion 160,
and facilitate navigation of the distal end portion 160 extending
out the distal opening of the outer sheath 180 in tortuous
vasculature. The proximal end portion 130 may be formed from
material that is stiffer than the distal portion 160 of the
delivery catheter 120, so that the proximal portion 130 has
sufficient pushability to advance through the patient's vascular
system, while the distal portion 160 may be formed of a more
flexible material so that the distal portion 160 may remain
flexible and track more easily over a guidewire to access remote
locations in tortuous regions of the vasculature. As best seen in
FIG. 2A, a tapered radiopaque marker 455, and atraumatic tip 457,
respectively, are disposed proximate a distal end opening 452 of
the delivery catheter 120.
[0031] Referring to FIGS. 2A-E, the implant 200, which may be a
stent, a flow diverter, or other type of vasculature implant, is
carried on a distal portion of the core wire 350. The implant 200
may comprise a variety of biocompatible materials, such as
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 implant
200 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.
[0032] As best seen in FIG. 2D, the implant 200 is generally
tubular, and has a proximal portion 220, a distal portion 240, and
an inner lumen 260 extending therebetween. Notably, the implant 200
is depicted in FIGS. 2A-E in a compressed, elongated delivery
configuration disposed (i.e., radially constrained) within the
lumen 125 of the delivery catheter 120. The implant 200 is
preferably biased to self-expand radially outwards into an expanded
deployed configuration when deployed out the distal end opening of
(i.e., no longer radially constrained within) the delivery catheter
120.
[0033] As shown in FIGS. 2A-B, the core wire 350 of the delivery
wire assembly 300 is coaxially disposed within the delivery
catheter lumen 125, and the implant 200 is coaxially disposed
around the core wire 350, also constrained within the delivery
catheter lumen 125. In particular, the core wire 350 is axially
movable relative to the delivery catheter 120, with the delivery
wire assembly 300 being configured to engage the implant 200 as the
core wire 350 is axially translated through the delivery catheter
lumen 125 for delivery of the implant 200 at a targeted
implantation site in a vasculature. The interface between the
delivery wire assembly 300 and the implant 200 is described in
further detail below.
[0034] Radiopaque markers 360 (e.g., laser etched, radiopaque bands
or any other suitable markers) are preferably located along the
distal portion of the core wire 350 to assist in positioning the
core wire 350 and implant 200 relative to the delivery catheter
120. In the illustrated embodiment, a coil 357 is disposed around
the core wire 350 for providing structural support just proximal of
the implant 200. A radiopaque marker band 360 is disposed on a
distal portion 358 of the coil 357 to indicate the location of the
proximal end portion 220 of the implant 200. An epoxy bond 376 is
used to attach the marker 360 to the core wire 350.
[0035] As shown in FIGS. 2B-C, a re-sheathing pad 370 is disposed
around the core wire 350 distal 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 bond 376 is used
to attach the re-sheathing bumper to the core wire 350. This region
of the core wire 350 onto which the implant 200 is loaded is
referred to herein as the implant loading region. In particular,
the proximal portion 220 of the implant 200 is disposed over the
respective re-sheathing pad 370 and re-sheathing bumper 375, and a
distal end of the distal portion 240 of the implant 200 is covered
by a distal protection feature 500 (FIG. 2E) that is attached to
the core wire 350 and secured between respective proximal and
distal locking members 550. In most of the figures, the only the
distal locking member 550 is shown, as the proximal locking member
550 is obscured by the implant distal protection feature 500.
However, the proximal locking member is shown in FIG. 5C (described
below). The atraumatic distal tip 380 (e.g., a soft coil member) is
attached to the core wire proximate to the distal locking member
550 (FIGS. 2B, 2E).
[0036] FIG. 3 illustrates the implant distal protection feature 500
of the delivery wire assembly 300, according to one embodiment of
the disclosed inventions. The implant distal protection feature 500
is preferably composed of biocompatible material, such as ePTFE or
the like. In one embodiment, the implant distal protection feature
500 is made of a thin, substantially uniform layer of ePTFE, having
a thickness of approximately 0.0152 millimeters (0.0006 inches),
and a length L of approximately 0.44 millimeters (0.0173 inches).
As shown in FIG. 3, the implant distal protection feature 500
comprises a peripheral portion in the form of three
circumferentially spaced apart petal-like members (or "petals") 520
that meet at a central portion 511 that is attached to the core
wire 350 (FIG. 2E). As shown in FIG. 4A (described below), the
peripheral petals 520 extend generally radially outward from the
central portion 511, and proximally directed, when the implant
distal protection feature 500 is not constrained within the
delivery catheter 120.
[0037] In the illustrated embodiment, the implant distal protection
feature 500 is fixedly attached to the core wire 350 by the locking
members 550, so that the implant distal protection feature does not
rotate relative to the core wire 350. In an alternative embodiment,
the implant distal protection feature 500 may be attached to a
collar (not shown) that is still fixed in a relative longitudinal
position on the core wire 350 by the locking members 550 in a
manner that allows the collar, and thus the implant distal
protection feature 550, to rotate relative to the core wire 350 and
locking members 550.
[0038] FIGS. 4A-D illustrate the front loading of the delivery wire
assembly 300 into the delivery catheter 120, according to one
embodiment of the disclosed inventions. FIG. 4A depicts the distal
end portion of the delivery wire assembly 300, including the
implant distal protection feature 500 and implant 200, just prior
to being loaded into the delivery catheter 120, wherein the
peripheral petals 520 of the implant distal protection feature 500
are shown extending generally proximally in a radially
unconstrained configuration. The implant 200 is coaxially disposed
around the core wire 350 (not shown), and held in the radially
constrained delivery configuration by a tubular loading member 390,
with the distal end portion 240 of the implant 200 is at least
partially exposed out a distal end opening of the loading member
390.
[0039] The distal end portion of the delivery wire assembly 300,
including the implant distal protection feature 500 and the
compressed implant 200, is either advanced into the delivery
catheter 120, or the delivery catheter 120 is advanced over the
distal portion of the delivery wire assembly 300, or some of each,
thereby radially compressing the peripheral petals 520 of the
implant distal protection feature 500 over and onto the distal
portion 240 of the implant 200, as shown in FIGS. 4B-C. Once the
delivery catheter 120 is disposed over the respective implant
distal protection feature 500 and loading member 390, the loading
member 390 is withdrawn, while the implant 200 remains in the
compressed delivery configuration within the lumen 125 of the
delivery catheter 120, and the peripheral petals 520 of the implant
distal protection feature 500 remain compressed onto, and at least
partially covering, the distal portion 240 of the implant 200 (FIG.
4D).
[0040] Although the disclosed inventions are not so limited, the
illustrated "three-petal" configuration of the implant distal
protection feature 500 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 resistive or
frictional forces imparted by the implant on the inner wall of the
delivery catheter 120 as the implant 200 is pushed through the
lumen 125. In particular, the inventor(s) of the disclosed
inventions have found that, by employing the depicted three-petal
configuration of the implant distal protection feature 500, the
coefficient of friction between the implant 200 and the inner wall
of the delivery catheter 120 ranges from approximately 0.01 to
approximately 0.04 when there is relative motion between the core
wire 350 and the delivery catheter 120.
[0041] In various embodiments, the implant distal protection
feature 550 may be sized and configured to cover differing amounts
of the distal end portion 240 of the implant 200 when a distal
portion of the delivery wire assembly 300 including the implant 200
and implant distal protection feature 500 is constrained within the
delivery catheter lumen 125. By way of non-limiting examples, in
one embodiment, the implant distal protection feature 500 is sized
and configured to cover as much as about twenty percent of a total
length of the implant 200 when a distal portion of the delivery
wire assembly 300 including the implant 200 and implant distal
protection feature 500 is constrained within the delivery catheter
lumen 125. In another embodiment, the implant distal protection
feature 500 is sized and configured to cover between about ten
percent and about twenty percent of a total length of the implant
200 when a distal portion of the delivery wire assembly 300
including the implant 200 and implant distal protection feature 500
is constrained within the delivery catheter lumen 125. In still
another embodiment, the implant distal protection feature 500 is
sized and configured to cover between about five percent and about
ten percent of a total length of the implant 200 when a distal
portion of the delivery wire assembly 300 including the implant 200
and implant distal protection feature 500 is constrained within the
delivery catheter lumen 125. In yet another embodiment, the implant
distal protection feature 500 is sized and configured to cover
about five percent or less of a total length of the implant 200
when a distal portion of the delivery wire assembly 300 including
the implant 200 and implant distal protection feature 500 is
constrained within the delivery catheter lumen 125.
[0042] FIGS. 5A-D' illustrate the implant distal protection feature
500 during delivery and deployment of the implant 200 to/at a
targeted site in a vasculature (not shown).
[0043] FIG. 5A, depicts a distal end portion of the delivery wire
assembly 300 as the core wire 350 (not seen in FIG. 5A) is pushed
through the delivery catheter lumen 125. The implant 200 and distal
implant protection member 500 shown in the compressed delivery
configuration, constrained within the delivery catheter lumen 125,
with the peripheral petals 520 of implant distal protection feature
500 covering and protecting the distal portion 240 of the implant
200
[0044] Once the distal end portion of the delivery assembly 300 is
located proximate to the targeted implantation site, the delivery
catheter 120 is withdrawn proximally relative to the core wire 350,
or the core wire 350 is pushed distally relative to the delivery
catheter 120, or some of each, thereby exposing the implant distal
protection feature 500 and the implant 200 out the distal end
opening 452 of the delivery catheter 120, allowing the no-longer
radially constrained implant 200 to self-expand radially, starting
at the distal end portion 240, to the expanded configuration, as
shown in FIGS. 5B-5D'. Notably, the peripheral petals 520 of the
implant distal protection feature 500 remain generally extending in
the proximal direction (i.e., in the "delivery configuration") as
the distal end portion 240 of the implant 200 assumes the expanded
configuration and is no longer covered by the implant distal
protection feature 500.
[0045] The implant distal protection feature 500 is preferably
configured to exert negligible or otherwise insignificant forces
over the distal portion 240 of the implant 200 as the implant 200
expands. In some embodiments, the implant distal protection feature
500 may outwardly radially expand when no longer radially
constrained by the delivery catheter 120. In either embodiment,
when the implant distal protection feature 500 retains the delivery
configuration or outwardly expands when no longer constrained by
the delivery catheter 120, the peripheral petals 520 are configured
to extend and/or face in a proximal direction, i.e., the individual
petals 520 preferably do not evert as the implant 200 expands.
[0046] After deployment of the implant 200 at the targeted site,
the delivery wire assembly 300 is withdrawn back into the delivery
catheter (not shown), and the delivery system 100 is withdrawn from
the body, leaving the expanded implant 200 implanted at the
targeted site. Notably, the core wire 350 and distal implant
protection member 500 are pulled through the lumen 260 of the
implant 200 and back into the delivery catheter lumen 125 without
interfering with the deployed expanded implant 200, due to the
implant distal protection feature 500 "proximal facing"
configuration and its relatively small size with respect to the
expanded implant 200, as shown in FIG. 5D-5D'. FIG. 5D' is an
enlarged view of the section shown in FIG. 5D, to better illustrate
that the implant distal protection feature 500 substantially
retains its delivery configuration even when the delivery catheter
120 is no longer constraining the implant distal protection feature
500.
[0047] Although particular embodiments have been shown and
described herein, it will be understood by those skilled in the art
that they are not intended to limit the disclosed inventions, and
it will be obvious to those skilled in the art that various
changes, permutations, and modifications may be made (e.g., the
dimensions of various parts, combinations of parts) without
departing from the scope of the disclosed inventions, which is to
be defined only by the following claims and their equivalents. The
specification and drawings are, accordingly, to be regarded in an
illustrative rather than restrictive sense. The various embodiments
shown and described herein are intended to cover alternatives,
modifications, and equivalents of the disclosed inventions, which
may be included within the scope of the appended claims.
* * * * *