U.S. patent application number 17/586025 was filed with the patent office on 2022-05-12 for occlusive medical device.
This patent application is currently assigned to BOSTON SCIENTIFIC SCIMED, INC.. The applicant listed for this patent is BOSTON SCIENTIFIC SCIMED, INC.. Invention is credited to Joshua Mark Inouye.
Application Number | 20220142650 17/586025 |
Document ID | / |
Family ID | |
Filed Date | 2022-05-12 |
United States Patent
Application |
20220142650 |
Kind Code |
A1 |
Inouye; Joshua Mark |
May 12, 2022 |
OCCLUSIVE MEDICAL DEVICE
Abstract
An example occlusive implant is disclosed. The example occlusive
implant includes an expandable framework including a height and a
plurality of support members defining a proximal end region of the
expandable framework and a central hub member attached to the
plurality of support members. Additionally, the expandable
framework is configured to shift between a first configuration and
a second configuration, wherein the height of the expandable
framework remains substantially the same in both the first
configuration and the second configuration. Further, the central
hub member is configured to shift relative to the proximal end
region while the expandable framework shifts between the first
configuration and the second configuration.
Inventors: |
Inouye; Joshua Mark; (Maple
Grove, MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
BOSTON SCIENTIFIC SCIMED, INC. |
Maple Grove |
MN |
US |
|
|
Assignee: |
BOSTON SCIENTIFIC SCIMED,
INC.
MAPLE GROVE
MN
|
Appl. No.: |
17/586025 |
Filed: |
January 27, 2022 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
16276141 |
Feb 14, 2019 |
11234706 |
|
|
17586025 |
|
|
|
|
62630805 |
Feb 14, 2018 |
|
|
|
International
Class: |
A61B 17/12 20060101
A61B017/12 |
Claims
1. (canceled)
2. An occlusive implant, comprising: a distal expandable framework
having a proximal end and a distal end, the distal expandable
framework configured to shift between a collapsed configuration and
an expanded configuration; a hub member having a distal end fixed
to the proximal end of the distal expandable framework; a proximal
occlusive disk fixed to a proximal end of the hub member, the
proximal disk disposed proximal of the distal expandable framework
in both the collapsed configuration and the expanded configuration;
and a first occlusive member disposed on a proximal end region of
the distal expandable framework, adjacent the hub member.
3. The occlusive implant of claim 2, wherein the distal expandable
framework has a height, wherein the height remains substantially
the same in both the collapsed configuration and the expanded
configuration.
4. The occlusive implant of claim 2, wherein the distal expandable
framework includes a plurality of support members, wherein proximal
ends of the plurality of support members are fixed to the hub
member and distal ends of the plurality of support members are
free.
5. The occlusive implant of claim 2, wherein the distal expandable
framework includes a longitudinal axis, wherein the hub member is
configured to shift along the longitudinal axis relative to the
proximal end region while the distal expandable framework shifts
between the collapsed configuration and the expanded
configuration.
6. The occlusive implant of claim 2, wherein the proximal occlusive
disk has an outer diameter greater than an outer diameter than the
distal expandable framework in the expanded configuration.
7. The occlusive implant of claim 6, wherein the outer diameter of
the proximal occlusive disk is reduced when the distal expandable
framework is in the collapsed configuration.
8. The occlusive implant of claim 2, wherein the proximal occlusive
disk is spaced apart axially from the distal expandable framework
by the hub member.
9. The occlusive implant of claim 2, further comprising a plurality
of anchor members extending radially outward from the distal
expandable framework.
10. The occlusive implant of claim 2, wherein the distal expandable
framework includes a first radial outward force in the collapsed
configuration and a second radial outward force in the expanded
configuration, and wherein the first radial outward force is
substantially equivalent to the second radial outward force.
11. The occlusive implant of claim 2, further comprising a second
occlusive member disposed along a distal end region of the distal
expandable framework.
12. The occlusive implant of claim 2, wherein the proximal
occlusive disk and the first occlusive member are made from the
same material.
13. An occlusive implant, comprising: a distal expandable framework
having a proximal end and a distal end and a height measured
therebetween, the distal expandable framework configured to shift
between a collapsed configuration and an expanded configuration; a
hub member having a distal end fixed to the proximal end of the
distal expandable framework, wherein the distal expandable
framework first extends radially outward from the hub member
defining the proximal end and then extends distally along the
height; and a proximal occlusive disk fixed to a proximal end of
the hub member, the proximal disk disposed proximal of the distal
expandable framework in both the collapsed configuration and the
expanded configuration.
14. The occlusive implant of claim 13, further comprising a first
occlusive member disposed on a proximal end region of the distal
expandable framework, adjacent the hub member.
15. The occlusive implant of claim 14, wherein the distal
expandable framework includes a longitudinal axis, wherein the hub
member is configured to shift along the longitudinal axis relative
to the proximal end region while the distal expandable framework
shifts between the collapsed configuration and the expanded
configuration.
16. The occlusive implant of claim 14, further comprising a second
occlusive member disposed along a distal end region of the distal
expandable framework.
17. The occlusive implant of claim 13, wherein the distal
expandable framework includes a plurality of support members,
wherein proximal ends of the plurality of support members are fixed
to the hub member and distal ends of the plurality of support
members are free.
18. The occlusive implant of claim 13, wherein the proximal
occlusive disk has an outer diameter greater than an outer diameter
than the distal expandable framework in the expanded
configuration.
19. The occlusive implant of claim 13, wherein the proximal
occlusive disk is spaced apart axially from the distal expandable
framework by the hub member.
20. The occlusive implant of claim 13, further comprising a
plurality of anchor members extending radially outward from the
distal expandable framework.
21. An occlusive implant, comprising: a distal expandable framework
configured to shift between a collapsed configuration and an
expanded configuration; a hub member having a distal end fixed to
the proximal end of the distal expandable framework; and a proximal
occlusive disk fixed to a proximal end of the hub member, the
proximal occlusive disk having an outer diameter greater than an
outer diameter of the distal expandable framework in the expanded
configuration; wherein the distal expandable framework includes a
plurality of support members having proximal ends fixed to the hub
member and free distal ends defining a distalmost end of the distal
expandable framework.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a continuation of U.S. application Ser.
No. 16/276,141, filed Feb. 14, 2019, which claims the benefit of
priority under 35 U.S.C. .sctn. 119 to U.S. Provisional Application
Ser. No. 62/630,805, filed Feb. 14, 2018, the entirety of which is
incorporated herein by reference.
BACKGROUND
[0002] The left atrial appendage (LAA) is a small organ attached to
the left atrium of the heart as a pouch-like extension. In patients
suffering from atrial fibrillation, the left atrial appendage may
not properly contract with the left atrium, causing stagnant blood
to pool within its interior, which can lead to the undesirable
formation of thrombi within the left atrial appendage. Thrombi
forming in the left atrial appendage may break loose from this area
and enter the blood stream. Thrombi that migrate through the blood
vessels may eventually plug a smaller vessel downstream and thereby
contribute to stroke or heart attack. Clinical studies have shown
that the majority of blood clots in patients with atrial
fibrillation are found in the left atrial appendage. As a
treatment, medical devices have been developed which are positioned
in the left atrial appendage and deployed to close off the ostium
of the left atrial appendage. Over time, the exposed surface(s)
spanning the ostium of the left atrial appendage becomes covered
with tissue (a process called endothelization), effectively
removing the left atrial appendage from the circulatory system and
reducing or eliminating the number of thrombi which may enter the
blood stream from the left atrial appendage. A continuing need
exists for improved medical devices and methods to control thrombus
formation within the left atrial appendage of patients suffering
from atrial fibrillation.
SUMMARY
[0003] This disclosure provides design, material, manufacturing
method, and use alternatives for medical devices. An example
occlusive implant includes an expandable framework including a
height and a plurality of support members defining a proximal end
region of the expandable framework and a central hub member
attached to the plurality of support members. Additionally, the
expandable framework is configured to shift between a first
configuration and a second configuration, wherein the height of the
expandable framework remains substantially the same in both the
first configuration and the second configuration. Further, the
central hub member is configured to shift relative to the proximal
end region while the expandable framework shifts between the first
configuration and the second configuration.
[0004] In addition or alternatively, wherein the expandable
framework includes a first radial outward force in the first
configuration and a second radial outward force in the second
configuration, and wherein the first radial outward force is
substantially equivalent to the second radial outward force.
[0005] In addition or alternatively, wherein the expandable
framework includes a longitudinal axis, and wherein central hub
member is configured to shift along the longitudinal axis.
[0006] In addition or alternatively, wherein the central hub member
shifts in a distal direction when shifting from the first
configuration to the second configuration.
[0007] In addition or alternatively, wherein the plurality of
support members define a recess within a central region of the
expandable framework.
[0008] In addition or alternatively, wherein the central hub member
is positioned within the recess.
[0009] In addition or alternatively, wherein the expandable member
has a first width in the first configuration and a second width in
the second configuration, wherein the first width is wider than the
second width.
[0010] In addition or alternatively, wherein the recess of the
expandable member has a first recess height in the first
configuration and a second recess height in the second
configuration, and wherein the second recess height is greater than
the first recess height.
[0011] In addition or alternatively, further comprising a first
occlusive member disposed along the proximal end region of the
expandable framework.
[0012] In addition or alternatively, further comprising a second
occlusive member disposed along a distal end region of the
expandable framework.
[0013] Another medical implant for occluding a left atrial
appendage includes:
[0014] an expandable framework including a first height, a proximal
end region and a plurality of support members defining a central
recessed region; and
[0015] a central hub member attached to the plurality of support
members and positioned within the central recessed region;
[0016] wherein the central recess region extends into the
expandable member a first distance;
[0017] wherein the expandable framework is configured to shift
between an expanded configuration and a collapsed
configuration;
[0018] wherein the first distance increases as the expandable
framework shifts between the expanded configuration and the
collapsed configuration.
[0019] In addition or alternatively, wherein the height of the
expandable framework remains substantially the same in both the
expanded configuration and the collapsed configuration.
[0020] In addition or alternatively, wherein the expandable
framework includes a first radial outward force in the expanded
configuration and a second radial outward force in the collapsed
configuration, and wherein the first radial outward force is
substantially equivalent to the second radial outward force.
[0021] In addition or alternatively, wherein the central hub member
is configured to shift relative to the proximal end region while
the expandable framework shifts between the expanded configuration
and the collapsed configuration.
[0022] In addition or alternatively, wherein the expandable
framework includes a longitudinal axis, and wherein the central hub
member is configured to shift along the longitudinal axis.
[0023] In addition or alternatively, wherein the central hub member
shifts in a distal direction when shifting from the expanded
configuration to the collapsed configuration.
[0024] In addition or alternatively, further comprising a first
occlusive member disposed along the proximal end region of the
expandable framework.
[0025] In addition or alternatively, further comprising a second
occlusive member disposed along a distal end region of the
expandable framework.
[0026] An example method for occluding a left atrial appendage
includes:
[0027] advancing an occlusive implant to the left atrial appendage,
the occlusive implant including: [0028] an expandable framework
including a height and a plurality of support members defining a
proximal end region of the expandable framework; [0029] a central
hub member attached to the plurality of support members; [0030]
wherein the expandable framework is configured to shift between a
first configuration and a second configuration; [0031] wherein the
height of the expandable framework remains substantially the same
in both the first configuration and the second configuration;
and
[0032] expanding the expandable framework within the left atrial
appendage such that the expandable framework shifts between the
first configuration and the second configuration.
[0033] In addition or alternatively, wherein expanding that
expandable framework from the first configuration to the second
expanded configuration shifts the central hub member relative to
the proximal end region
[0034] The above summary of some embodiments, aspects, and/or
examples is not intended to describe each embodiment or every
implementation of the present disclosure. The figures and the
detailed description which follows more particularly exemplify
these embodiments.
BRIEF DESCRIPTION OF THE DRAWINGS
[0035] The disclosure may be more completely understood in
consideration of the following detailed description of various
embodiments in connection with the accompanying drawings, in
which:
[0036] FIG. 1 illustrates an example occlusive implant positioned
in the heart;
[0037] FIG. 2 is a plan view of an example occlusive implant;
[0038] FIG. 2A is a plan view of another example occlusive
implant;
[0039] FIG. 3 is a plan view of another example occlusive
implant;
[0040] FIG. 4 is a plan view of another example occlusive
implant;
[0041] FIG. 5 is a plan view of another example occlusive
implant;
[0042] FIG. 6 illustrates an example occlusive implant positioned
in the left atrial appendage;
[0043] FIG. 7 illustrates another example occlusive implant
positioned in the left atrial appendage;
[0044] FIG. 8 is a plan view of an example occlusive implant;
[0045] FIG. 9 illustrates an example occlusive implant positioned
in the left atrial appendage;
[0046] FIG. 10 illustrates another example occlusive implant
positioned in the left atrial appendage;
[0047] FIG. 11 is a plan view of another example occlusive
implant;
[0048] FIG. 12 is a plan view of the occlusive implant of FIG. 11
in a collapsed configuration.
[0049] While aspects of the disclosure are amenable to various
modifications and alternative forms, specifics thereof have been
shown by way of example in the drawings and will be described in
detail. It should be understood, however, that the intention is not
to limit aspects of the disclosure to the particular embodiments
described. On the contrary, the intention is to cover all
modifications, equivalents, and alternatives falling within the
spirit and scope of the disclosure.
DETAILED DESCRIPTION
[0050] The following description should be read with reference to
the drawings, which are not necessarily to scale, wherein like
reference numerals indicate like elements throughout the several
views. The detailed description and drawings are intended to
illustrate but not limit the claimed disclosure. Those skilled in
the art will recognize that the various elements described and/or
shown may be arranged in various combinations and configurations
without departing from the scope of the disclosure. The detailed
description and drawings illustrate example embodiments of the
claimed disclosure. However, in the interest of clarity and ease of
understanding, while every feature and/or element may not be shown
in each drawing, the feature(s) and/or element(s) may be understood
to be present regardless, unless otherwise specified.
[0051] For the following defined terms, these definitions shall be
applied, unless a different definition is given in the claims or
elsewhere in this specification.
[0052] All numeric values are herein assumed to be modified by the
term "about," whether or not explicitly indicated. The term
"about", in the context of numeric values, generally refers to a
range of numbers that one of skill in the art would consider
equivalent to the recited value (e.g., having the same function or
result). In many instances, the term "about" may include numbers
that are rounded to the nearest significant figure. Other uses of
the term "about" (e.g., in a context other than numeric values) may
be assumed to have their ordinary and customary definition(s), as
understood from and consistent with the context of the
specification, unless otherwise specified.
[0053] The recitation of numerical ranges by endpoints includes all
numbers within that range, including the endpoints (e.g., 1 to 5
includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).
[0054] Although some suitable dimensions, ranges, and/or values
pertaining to various components, features and/or specifications
are disclosed, one of skill in the art, incited by the present
disclosure, would understand desired dimensions, ranges, and/or
values may deviate from those expressly disclosed.
[0055] 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. It is to be noted that in order to facilitate
understanding, certain features of the disclosure may be described
in the singular, even though those features may be plural or
recurring within the disclosed embodiment(s). Each instance of the
features may include and/or be encompassed by the singular
disclosure(s), unless expressly stated to the contrary. For
simplicity and clarity purposes, not all elements of the disclosure
are necessarily shown in each figure or discussed in detail below.
However, it will be understood that the following discussion may
apply equally to any and/or all of the components for which there
are more than one, unless explicitly stated to the contrary.
Additionally, not all instances of some elements or features may be
shown in each figure for clarity.
[0056] Relative terms such as "proximal", "distal", "advance",
"retract", variants thereof, and the like, may be generally
considered with respect to the positioning, direction, and/or
operation of various elements relative to a
user/operator/manipulator of the device, wherein "proximal" and
"retract" indicate or refer to closer to or toward the user and
"distal" and "advance" indicate or refer to farther from or away
from the user. In some instances, the terms "proximal" and "distal"
may be arbitrarily assigned in an effort to facilitate
understanding of the disclosure, and such instances will be readily
apparent to the skilled artisan. Other relative terms, such as
"upstream", "downstream", "inflow", and "outflow" refer to a
direction of fluid flow within a lumen, such as a body lumen, a
blood vessel, or within a device.
[0057] The term "extent" may be understood to mean a greatest
measurement of a stated or identified dimension, unless the extent
or dimension in question is preceded by or identified as a
"minimum", which may be understood to mean a smallest measurement
of the stated or identified dimension. For example, "outer extent"
may be understood to mean a maximum outer dimension, "radial
extent" may be understood to mean a maximum radial dimension,
"longitudinal extent" may be understood to mean a maximum
longitudinal dimension, etc. Each instance of an "extent" may be
different (e.g., axial, longitudinal, lateral, radial,
circumferential, etc.) and will be apparent to the skilled person
from the context of the individual usage. Generally, an "extent"
may be considered a greatest possible dimension measured according
to the intended usage, while a "minimum extent" may be considered a
smallest possible dimension measured according to the intended
usage. In some instances, an "extent" may generally be measured
orthogonally within a plane and/or cross-section, but may be, as
will be apparent from the particular context, measured
differently--such as, but not limited to, angularly, radially,
circumferentially (e.g., along an arc), etc.
[0058] The terms "monolithic" and "unitary" shall generally refer
to an element or elements made from or consisting of a single
structure or base unit/element. A monolithic and/or unitary element
shall exclude structure and/or features made by assembling or
otherwise joining multiple discrete elements together.
[0059] It is noted that references in the specification to "an
embodiment", "some embodiments", "other embodiments", etc.,
indicate that the embodiment(s) described may include a particular
feature, structure, or characteristic, but every embodiment may not
necessarily include the particular feature, structure, or
characteristic. Moreover, such phrases are not necessarily
referring to the same embodiment. Further, when a particular
feature, structure, or characteristic is described in connection
with an embodiment, it would be within the knowledge of one skilled
in the art to effect the particular feature, structure, or
characteristic in connection with other embodiments, whether or not
explicitly described, unless clearly stated to the contrary. That
is, the various individual elements described below, even if not
explicitly shown in a particular combination, are nevertheless
contemplated as being combinable or arrangeable with each other to
form other additional embodiments or to complement and/or enrich
the described embodiment(s), as would be understood by one of
ordinary skill in the art.
[0060] For the purpose of clarity, certain identifying numerical
nomenclature (e.g., first, second, third, fourth, etc.) may be used
throughout the description and/or claims to name and/or
differentiate between various described and/or claimed features. It
is to be understood that the numerical nomenclature is not intended
to be limiting and is exemplary only. In some embodiments,
alterations of and deviations from previously-used numerical
nomenclature may be made in the interest of brevity and clarity.
That is, a feature identified as a "first" element may later be
referred to as a "second" element, a "third" element, etc. or may
be omitted entirely, and/or a different feature may be referred to
as the "first" element. The meaning and/or designation in each
instance will be apparent to the skilled practitioner.
[0061] The occurrence of thrombi in the left atrial appendage (LAA)
during atrial fibrillation may be due to stagnancy of blood pooling
in the LAA. The pooled blood may still be pulled out of the left
atrium by the left ventricle, however less effectively due to the
irregular contraction of the left atrium caused by atrial
fibrillation. Therefore, instead of an active support of the blood
flow by a contracting left atrium and left atrial appendage,
filling of the left ventricle may depend primarily or solely on the
suction effect created by the left ventricle. However, the
contraction of the left atrial appendage may not be in sync with
the cycle of the left ventricle. For example, contraction of the
left atrial appendage may be out of phase up to 180 degrees with
the left ventricle, which may create significant resistance to the
desired flow of blood. Further still, most left atrial appendage
geometries are complex and highly variable, with large irregular
surface areas and a narrow ostium or opening compared to the depth
of the left atrial appendage. These aspects as well as others,
taken individually or in various combinations, may lead to high
flow resistance of blood out of the left atrial appendage.
[0062] In an effort to reduce the occurrence of thrombi formation
within the left atrial appendage and prevent thrombi from entering
the blood stream from within the left atrial appendage, it may be
desirable to develop medical devices and/or occlusive implants that
close off the left atrial appendage from the heart and/or
circulatory system, thereby lowering the risk of stroke due to
thrombolytic material entering the blood stream from the left
atrial appendage. Example medical devices and/or occlusive implants
which seal the left atrial appendage (or other similar openings)
are disclosed herein.
[0063] FIG. 1 illustrates an example occlusive implant 10
positioned within the left atrial appendage 50. FIG. 1 further
illustrates that the occlusive implant 10 may be inserted and
advanced through a body lumen via an occlusive implant delivery
system 20. In some instances, an occlusive implant delivery system
20 may include a delivery catheter 24 which is guided toward the
left atrium via various chambers and lumens of the heart (e.g., the
inferior vena cava, superior vena cava, the right atrium, etc.) to
a position adjacent the left atrial appendage 50.
[0064] The delivery system 20 may include a hub 22. The hub 22 may
be manipulated by a clinician to direct the distal end region of
the delivery catheter 24 to a position adjacent the left atrial
appendage 50. In some embodiments, an occlusive implant delivery
system 20 may include a core wire 18. Further, a proximal end 11 of
the occlusive implant 10 may be configured to releasably attach,
join, couple, engage, or otherwise connect to the distal end of the
core wire 18. In some embodiments, the proximal end region 11 of
the occlusive implant 10 may include a threaded insert coupled
thereto. In some embodiments, the threaded insert may be configured
to and/or adapted to couple with, join to, mate with, or otherwise
engage a threaded member disposed at the distal end of a core wire
18. Other means of releasably coupling and/or engaging the proximal
end of the occlusive implant 10 to the distal end of the core wire
18 are also contemplated.
[0065] FIG. 1 further illustrates the occlusive implant 10
positioned adjacent the left atrial appendage 50 via the delivery
catheter 24 (described above). It can be appreciated that in some
examples, the implant 10 may be configured to shift between a
collapsed configuration and an expanded configuration. For example,
in some instances, the occlusive implant 10 may be in a collapsed
configuration during delivery via the occlusion implant delivery
system 20, whereby the occlusive implant 10 expands to an expanded
configuration once deployed from the occlusion implant delivery
system 20.
[0066] Additionally, FIG. 1 illustrates that the occlusive implant
10 may include an expandable framework 12. The expandable framework
12 may be compliant and, therefore, substantially conform to and/or
be in sealing engagement with the shape and/or geometry of a
lateral wall of a left atrial appendage 50 in the expanded
configuration. In some embodiments, the occlusive implant 10 may
expand to a size, extent, or shape less than or different from a
maximum unconstrained extent, as determined by the surrounding
tissue and/or lateral wall of the left atrial appendage 50.
Further, it can be appreciated that the elements of the expandable
framework 12 may be tailored to increase the flexibility of the
expandable framework 12 and/or the occlusive implant 10, thereby
permitting the expandable framework 12 and/or the occlusive implant
10 to conform to the tissue around it, rather than forcing the
tissue to conform to the expandable framework 12 and/or the
occlusive implant 10. Additionally, in some instances, it may be
desirable to design the occlusive implant 10 to include various
features, components and/or configurations which improve the
sealing capabilities of the occlusive implant 10 within the left
atrial appendage.
[0067] FIG. 1 illustrates that the distal end region 13 of the
expandable framework 12 may extend farther into the left atrial
appendage 50 as compared to the proximal end region 11 of the
expandable framework 12. It can be appreciated that as the
expandable framework 12 is advanced into the left atrial appendage
50, the distal end region 13 may engage with tissue defining the
left atrial appendage 50. In other words, in some examples the
distal end region 13 may be considered the "leading" region of the
expandable framework 12 as it enters into the left atrial appendage
50. However, this is not intended to be limiting. Rather, in some
examples the proximal end region 11 may be considered the "leading"
region of the expandable framework 12 as it enters into the left
atrial appendage 50.
[0068] FIG. 2 illustrates an example occlusive implant 10. The
implant 10 may include an expandable framework 12. The expandable
framework 12 may include a proximal end region 11 and a distal end
region 13. FIG. 2 further illustrates that the expandable framework
12 may include one or more projections 17 extending in a
proximal-to-distal direction. In some instances (such as that shown
in FIG. 2), plurality of projections 17 may extend
circumferentially around a longitudinal axis 52 of the expandable
framework 12. In other words, in some examples the projections 17
may resemble the peaks of a "crown" extending circumferentially
around a longitudinal axis 52 of the expandable framework 12. While
the above discussion (and the illustration shown in FIG. 2), shows
a plurality of projections 17, it is contemplated that the
occlusive implant 10 may include 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11,
12 or more individual projections 17 disposed in a variety of
arrangements along the expandable framework 12.
[0069] Additionally, FIG. 2 illustrates that the proximal end
region 11 of the expandable framework 12 may include a plurality of
support members 19 extending circumferentially around the
longitudinal axis 52 of the expandable framework 12. FIG. 2
illustrates that that plurality of support members 19 may include
one or more curved portions which are shaped such that they define
a "recess" 21 extending distally into the expandable framework 12.
As illustrated in FIG. 2, the recess 21 may extend
circumferentially around the longitudinal axis 52. Further, FIG. 2
illustrates that each of the plurality of support members 19 may
include a first end 25 which is attached to a central hub 23. It
can be appreciated that the central hub 23 may be aligned along the
longitudinal axis 52 of the expandable framework 12. As will be
described in greater detail below, FIG. 2 illustrates that the hub
23 may be positioned such that it lies within the recess 21 defined
by the plurality of support members 19.
[0070] The occlusive implant 10 may also include a first occlusive
member 14 disposed on, disposed over, disposed about, or covering
at least a portion of the expandable framework 12. In some
embodiments, the first occlusive member 14 may be disposed on,
disposed over, disposed about or cover at least a portion of an
outer (or outwardly-facing) surface of the expandable framework 12.
FIG. 2 further illustrates that the first occlusive member 14 may
extend only partially along the longitudinal extent of the
expandable framework 12. However, this is not intended to be
limiting. Rather, the first occlusive member 14 may extend along
the longitudinal extent of the expandable framework 12 to any
degree (e.g., the full longitudinal extend of the expandable
framework 12).
[0071] In some embodiments, the first occlusive member 14 may be
permeable or impermeable to blood and/or other fluids, such as
water. In some embodiments, the first occlusive member 14 may
include a woven, braided and/or knitted material, a fiber, a
sheet-like material, a fabric, a polymeric membrane, a metallic or
polymeric mesh, a porous filter-like material, or other suitable
construction. In some embodiments, the first occlusive member 14
may prevent thrombi (i.e. blood clots, etc.) from passing through
the first occlusive member 14 and out of the left atrial appendage
into the blood stream. In some embodiments, the first occlusive
member 14 may promote endothelialization after implantation,
thereby effectively removing the left atrial appendage from the
patient's circulatory system. Some suitable, but non-limiting,
examples of materials for the first occlusive member 14 are
discussed below.
[0072] FIG. 2 further illustrates that the expandable framework 12
may include a plurality of anchor members 16 disposed about a
periphery of the expandable framework 12. The plurality of anchor
members 16 may extend radially outward from the expandable
framework 12. In some embodiments, at least some of the plurality
of anchor members 16 may each have and/or include a body portion
and a tip portion projecting circumferentially therefrom, as shown
in FIG. 2. Some suitable, but non-limiting, examples of materials
for the expandable framework 12 and/or the plurality of anchor
members 16 are discussed below.
[0073] In some examples, the expandable framework 12 and the
plurality of anchor members 16 may be integrally formed and/or cut
from a unitary member. In some embodiments, the expandable
framework 12 and the plurality of anchor members 16 may be
integrally formed and/or cut from a unitary tubular member and
subsequently formed and/or heat set to a desired shape in the
expanded configuration. In some embodiments, the expandable
framework 12 and the plurality of anchor members 16 may be
integrally formed and/or cut from a unitary flat member, and then
rolled or formed into a tubular structure and subsequently formed
and/or heat set to the desired shape in the expanded configuration.
Some exemplary means and/or methods of making and/or forming the
expandable framework 12 include laser cutting, machining, punching,
stamping, electro discharge machining (EDM), chemical dissolution,
etc. Other means and/or methods are also contemplated.
[0074] As illustrated in FIG. 2, the plurality of anchor members 16
disposed along the expandable framework 12 may include two rows of
anchor members 16. However, this is not intended to be limiting.
Rather, the expandable framework 12 may include a single row of
anchor members 16. In other examples, the expandable framework 12
may include more than two rows of anchor members 16. For example,
in some instances the expandable framework 12 may include 1, 2, 3,
4 or more rows of anchor members 16.
[0075] While FIG. 2 illustrates an expandable framework 12 which
may be formed from a unitary member, this is not intended to be
limiting. Rather, it is contemplated the expandable member 12 may
include a variety of different configurations which may be formed
via a variety of manufacturing techniques. For example, FIG. 2A
illustrates another example occlusive implant 10'. FIG. 2A further
illustrates that the example occlusive implant 10' may include an
expandable framework 12'. As illustrated in FIG. 2A, the expandable
framework 12' may be formed as a braided structure (e.g., a
framework formed by braiding one or more filaments together).
Additionally, the expandable framework 12' may include one or more
of the features described above with respect to FIG. 2.
[0076] As discussed above, it may be desirable to design the
occlusive implant 10 described herein to include features which
allow it to accommodate patient-to-patient variability in the shape
of the left atrial appendage. In other words, it may be desirable
to design the occlusive implant 10 such that a clinician may
utilize the same device irrespective of the particular anatomy
presented by a particular patient. For example, it is known that
the diameter of the opening (e.g., orifice) of the left atrial
appendage may vary widely among individuals. In particular, the
diameter of the opening to the left atrial appendage may be
narrower in certain individuals as compared to others. Therefore,
it may be desirable to design the occlusive implant 10 such that it
can change its shape to fit different orifice diameters of the left
atrial appendage without sacrificing its effectiveness in sealing
the left atrial appendage. In particular, it may be desirable to
design the occlusive implant 10 such that it can expand or collapse
its width without substantially changing the distance in which it
extends into the left atrial appendage and without substantially
changing the radial force in which it exerts upon the surrounding
tissue. FIGS. 3-5 illustrate an example occlusive implant 10 which
may expand or collapse its width without substantially changing the
distance in which it extends into the left atrial appendage and
without substantially changing the radial force in which the
implant exerts upon surrounding tissue
[0077] In the interest of simplicity, FIG. 3 illustrates a
"silhouette" of the occlusive implant 10 (described above) in an
expanded configuration. In particular, FIG. 3 illustrates an
outline of the expandable framework 12 including a distal end
region 13 and a proximal end region 11. Further, FIG. 3 illustrates
two of the plurality of support members 19 of the expandable
framework 12 described above. The support members 19 may be
positioned adjacent to the proximal end region 11. Additionally,
FIG. 3 illustrates the first ends 25 of each of the support members
19 attached to a central hub 23. The central hub 23 may be aligned
with the longitudinal axis 52 of the occlusive member 10 and
partially extend into a recess 21 defined by curved portions of the
support members 19.
[0078] As discussed above, FIG. 3 illustrates the occlusive implant
10 in an expanded configuration (e.g., an expanded configuration as
compared to the configuration of the implant 10 shown in FIG. 2,
above). FIG. 3 illustrates that the expandable framework 12 may
include a "height" defined as the distance between the proximal end
region 11 and the distal end region 13. As shown in FIG. 3, the
height of the expandable framework 12 is depicted as "X." As will
be described in greater detail below, the height of the occlusive
implant 10 may correspond to the distance in which the implant
extends into a left atrial appendage. Additionally, FIG. 3 shows
that the expandable framework 12 may include a width depicted as
"Y.sub.1." Further, FIG. 3 shows that the expandable recess 21
(e.g., the recess defined by the support members 19) may include a
depth depicted as "Z.sub.1."
[0079] FIG. 4 illustrates the occlusive implant 10 after having
shifted from the expanded configuration shown in FIG. 3 to a more
collapsed configuration. In some examples, the occlusive implant 10
shown in FIG. 4 may represent the occlusive implant 10 illustrated
and described above with respect to FIG. 2. It can further be
appreciated from FIG. 4 that, as compared to the expanded implant
shown in FIG. 3, the expandable framework 12 shown in FIG. 4 has
been shifted to a narrower configuration as compared with the
implant shown in FIG. 3. For example, FIG. 4 shows that the
expandable framework 12 may include a width depicted as "Y.sub.2."
As discussed, the width Y.sub.2 of FIG. 4 may be less than the
width Y.sub.1 of FIG. 3.
[0080] Additionally, while FIG. 4 shows the implant 10 having a
narrower width (as compared to the implant shown in FIG. 3), FIG. 4
further illustrates that the "height" (defined as the distance
between the proximal end region 11 and the distal end region 13)
may remain substantially constant. For example, the height of the
expandable framework 12 in FIG. 4 may remain as "X," which
represents the same height of the expandable framework 12
illustrated in FIG. 3.
[0081] However, in order for the width of the expandable framework
12 to shift while maintaining a constant height, the plurality of
support members 19 may curl (e.g., bend, flex, etc.) radially
inward and upward toward the distal end region 13, thereby
deepening the recess 21 within the expandable framework 12. For
example, FIG. 4 shows the depth of the recess 21 depicted as
"Z.sub.2," whereby the distance Z.sub.2 is greater than Z.sub.1
shown in FIG. 3. Further, it can be appreciated from FIG. 4 that as
the support members 19 curl radially inward and upward toward the
distal end region 13 of the expandable framework 12, the hub member
23 may shift in a proximal-to-distal direction along the
longitudinal axis 52.
[0082] FIG. 5 illustrates the occlusive implant 10 after having
shifted from the configuration shown in FIG. 4 to an even narrower
configuration. For example, as compared to the implant 10 shown in
FIG. 4, the expandable framework 12 shown in FIG. 5 has been
shifted to a collapsed configuration as compared with the implant
shown in FIG. 4. For example, FIG. 5 shows that the expandable
framework 12 may include a width depicted as "Y.sub.3." As
discussed, the width Y.sub.3 of FIG. 5 may be less than the width
Y.sub.1 of FIG. 3 and Y.sub.2 of FIG. 4.
[0083] As discussed above, while FIG. 5 shows the implant 10 having
a narrower width (as compared to the implants shown in FIG. 3 and
FIG. 4), FIG. 5 further illustrates that the "height" (defined as
the distance between the proximal end region 11 and the distal end
region 13) may remain substantially constant. For example, the
height of the expandable framework 12 in FIG. 5 may remain as "X,"
which represents the same height of the expandable framework 12 as
illustrated in FIG. 3 and FIG. 4.
[0084] Additionally, FIG. 5 illustrates that as the implant 10
continues narrows from an expanded configuration to a collapsed
configuration, the plurality of support arms 19 may curl radially
inward and upward toward the distal end region 13, thereby
extending the recess 21 into the expandable framework 12. For
example, FIG. 5 shows the depth of the recess 21 depicted as
"Z.sub.3," whereby the distance Z.sub.3 is greater than Z.sub.1
shown in FIG. 3 and Z.sub.2 shown in FIG. 4. Further, it can be
appreciated from FIG. 5 that as the support members 19 continue to
curl radially inward and upward toward the distal end region 13 of
the expandable framework 12, the hub member 23 may shift in a
proximal-to-distal direction along the longitudinal axis 52.
[0085] As discussed above, in some instances it may be desirable to
design implant 10 (or any other implants discussed herein) to
maintain a substantially constant radial outward force independent
of the particular configuration (e.g., geometry) the implant 10 may
assume when positioned within left atrial appendages of different
sizes and shapes. For example, it is contemplated that each of the
configurations of the implant 10 illustrated in FIGS. 3-5 may exert
a substantially equivalent outward radial force upon the walls of
an atrial appendage. This design feature is present in the implant
10 because the "Z" dimension is the bending moment arm of the
supporting members 19, and hence, because the "Z" dimension varies
inversely with the device diameter, the device is able to maintain
approximately constant radial force independent of its particular
deployed geometry. For example, at low diameters the material
strain is high, however, the bending moment is large. However, at
high diameters the material strain is low, however, the bending
moment is small. This feature gives rise to approximately constant
outward radial force from the supporting members 19 throughout a
range of configurations (e.g., a range of configurations
illustrated in FIGS. 3-5).
[0086] FIG. 6 and FIG. 7 illustrates the occlusive implant 10
positioned within an example left atrial appendage 50. Further,
FIG. 6 illustrates the implant 10 being positioned in a left atrial
appendage having a wider orifice, while FIG. 7 illustrates the
implant 10 being positioned in a left atrial appendage having a
narrower orifice (as compared to FIG. 6).
[0087] As shown, FIG. 6 and FIG. 7 illustrate that the expandable
framework 12 may be compliant and, therefore, substantially conform
to and/or be in sealing engagement with the shape and/or geometry
of a lateral wall 53 of a left atrial appendage 50. In some
embodiments, the occlusive implant 10 may expand to a size, extent,
or shape less than or different from a maximum unconstrained
extent, as determined by the surrounding lateral wall 53 of the
left atrial appendage. Additionally, FIG. 6 and FIG. 7 illustrate
that the expandable framework 12 may be held fixed adjacent to the
left atrial appendage by one or more anchoring members 16.
[0088] Additionally, FIG. 6 illustrates the occlusive implant 10
positioned within the opening to the left atrial appendage 50 such
that it extends into the appendage a distance depicted as "W."
Further, it can be appreciated from FIG. 6 that the opening to the
left atrial appendage 50 shown in FIG. 6 may require that the
occlusive member 10 expand to a wide configuration (similar to the
configuration shown in FIG. 3). In this expanded configuration, the
hub 23 is positioned adjacent to the proximal end region of the
occlusive member 10.
[0089] As discussed above, FIG. 7 illustrates the occlusive implant
10 is positioned within a left atrial appendage 50 having narrower
opening as compared to the left atrial appendage illustrated in
FIG. 6. However, FIG. 7 further illustrates that even though the
implant 10 is positioned within a left atrial appendage 50 having a
narrower opening, the distance in which it extends into the left
atrial appendage 50 remains substantially constant. In other words,
even though the occlusive implant 10 deployed within a narrower
orifice, the distance it extends into the left atrial appendage 50
remains "W." Further, it can be appreciated from FIG. 7 that the
opening to the left atrial appendage 50 shown in FIG. 7 may require
that the occlusive member collapse to a narrower configuration
(similar to the configuration shown in FIG. 5). As discussed above,
in this narrowed configuration, the plurality of support members
(not shown in FIG. 7) may curl radially inward and upward toward
the distal end region 13 such that the hub 23 extends within a
deepened recess 21 of the expandable framework 12.
[0090] FIG. 8 illustrates another example occlusive member 110. The
occlusive member 110 may be similar in form and function to the
occlusive member 10 described above. For example, the occlusive
member 110 may include an expandable framework 112 and a first
occlusive member 114 disposed along a proximal end region 111 of
the expandable framework 112. Additionally, the expandable
framework 112 may include a plurality of anchor members 116
disposed about a periphery of the expandable framework 112. The
plurality of anchor members 116 may extend radially outward from
the expandable framework 112. Some suitable, but non-limiting,
examples of materials for the expandable framework 112 and/or the
plurality of anchor members 116 are discussed below.
[0091] Further, FIG. 8 illustrates that the occlusive member 110
may include a second occlusive member 115 disposed along a distal
end region 113 of the expandable framework 112. In some
embodiments, the second occlusive member 115 may be disposed on,
disposed over, disposed about or cover at least a portion of an
outer (or outwardly-facing) surface of the expandable framework
112. FIG. 8 further illustrates that the second occlusive member
115 may extend only partially along the longitudinal extent of the
expandable framework 112. However, this is not intended to be
limiting. Rather, the second occlusive member 115 may extend along
the longitudinal extent of the expandable framework 112 to any
degree (e.g., the full longitudinal extend of the expandable
framework 112).
[0092] In some embodiments, the second occlusive member 115 may be
permeable or impermeable to blood and/or other fluids, such as
water. In some embodiments, the second occlusive member 115 may
include a woven, braided and/or knitted material, a fiber, a
sheet-like material, a fabric, a polymeric membrane, a metallic or
polymeric mesh, a porous filter-like material, or other suitable
construction. In some embodiments, the second occlusive member 115
may prevent thrombi (i.e. blood clots, etc.) from passing through
the second occlusive member 115 and out of the left atrial
appendage into the blood stream. Some suitable, but non-limiting,
examples of materials for the second occlusive member 115 are
discussed below.
[0093] Similar to FIG. 6 and FIG. 7 above, FIG. 9 and FIG. 10
illustrate the occlusive implant 110 positioned within an example
left atrial appendage 50. For simplicity purposes, the implant 110
is shown with the second occlusive member 115 positioned on the
distal end region 113, but omits the first occlusive member 114.
However, it is contemplated that the implant 110 may include the
first occlusive member 114, the second occlusive member 115 or both
the first occlusive member 114 and the second occlusive member 115.
Further, FIG. 9 illustrates the implant 10 being positioned in a
left atrial appendage having a wider orifice, while FIG. 10
illustrates the implant 10 being positioned in a left atrial
appendage having a narrower orifice (as compared to FIG. 9).
[0094] As shown, FIG. 9 and FIG. 10 illustrate that the expandable
framework 112 may be compliant and, therefore, substantially
conform to and/or be in sealing engagement with the shape and/or
geometry of a lateral wall 53 of a left atrial appendage 50. In
some embodiments, the occlusive implant 110 may expand to a size,
extent, or shape less than or different from a maximum
unconstrained extent, as determined by the surrounding lateral wall
53 of the left atrial appendage. Additionally, FIG. 9 and FIG. 10
illustrate that the expandable framework 112 may be held fixed
adjacent to the left atrial appendage by one or more anchoring
members 116.
[0095] Additionally, FIG. 9 illustrates the occlusive implant 110
positioned within the opening to the left atrial appendage 50 such
that the proximal end region 111 extends into the appendage 50 a
distance depicted as "W" and the distal end region 113 is
positioned adjacent to the opening of the left atrial appendage.
Further, it can be appreciated from FIG. 9 that the opening to the
left atrial appendage 50 shown in FIG. 9 may require that the
occlusive member 110 expand to a wide configuration. In this
expanded configuration, the hub 123 is positioned adjacent to the
proximal end region 111 of the occlusive member 10.
[0096] As discussed above, FIG. 10 illustrates the occlusive
implant 110 is positioned within a left atrial appendage 50 having
narrower opening as compared to the left atrial appendage
illustrated in FIG. 9. However, FIG. 10 further illustrates that
even though the implant 110 is positioned within a left atrial
appendage 50 having a narrower opening, the distance in which it
extends into the left atrial appendage 50 remains substantially
constant. In other words, even though the occlusive implant 110 is
deployed within a narrower orifice, the distance it extends into
the left atrial appendage 50 remains "W." Further, it can be
appreciated from FIG. 10 that the opening to the left atrial
appendage 50 shown in FIG. 10 may require that the occlusive member
collapse to a narrower configuration. As discussed above, in this
narrowed configuration, the plurality of support members (not shown
in FIG. 10) may curl radially inward and upward toward the distal
end region 113 such that the hub 123 extends within a deepened
recess 121 of the expandable framework 112.
[0097] FIG. 11 illustrates another example occlusive member 210. It
can be appreciated that FIG. 11 illustrates the occlusive member
210 in an expanded configuration. The occlusive member 210 may be
similar in form and function to the occlusive member 10 described
above. For example, the occlusive member 210 may include an
expandable framework 212 and an occlusive member 214 disposed along
a proximal end region 211 of the expandable framework 212.
Additionally, FIG. 11 illustrates that the occlusive member 210 may
include an occlusive disk 256 positioned adjacent to the proximal
end region 211 of the occlusive member 210. In some embodiments,
the occlusive disk 256 may include a woven, braided and/or knitted
material, a fiber, a sheet-like material, a fabric, a polymeric
membrane, a metallic or polymeric mesh, a porous filter-like
material, or other suitable construction. Additionally, FIG. 11
illustrates that the occlusive disk 256 may include an attachment
region 264 which is coupled to the hub member 232 of the occlusive
implant 210.
[0098] FIG. 12 illustrates the occlusive member shown in FIG. 11 in
a collapsed (e.g., narrowed) configuration. As can be appreciated
from FIG. 12, the occlusive disk 256 (described above) may narrow
as the occlusive member 210 narrows. Further, it can be appreciated
that the attachment region 264 of the occlusive disk 256 may extend
into the recess of the expandable member 212. In other words, as
the support members (not shown in FIG. 12 but described above) of
the expandable framework 212 curl radially inward and upward toward
the distal end region 213, the attachment region 264 may be
"pulled" by the hub member 232 up into the recess within the
expandable member. Accordingly, as the attachment region 264 is
pulled into the recess, the occlusive disk 256 member may narrow
while remaining positioned adjacent to the proximal end region
211.
[0099] The materials that can be used for the various components of
the occlusive implant 10 (and variations, systems or components
thereof disclosed herein) and the various elements thereof
disclosed herein may include those commonly associated with medical
devices. For simplicity purposes, the following discussion makes
reference to the occlusive implant 10 (and variations, systems or
components disclosed herein). However, this is not intended to
limit the devices and methods described herein, as the discussion
may be applied to other elements, members, components, or devices
disclosed herein.
[0100] In some embodiments, the occlusive implant 10 (and
variations, systems or components thereof disclosed herein) may be
made from a metal, metal alloy, polymer (some examples of which are
disclosed below), a metal-polymer composite, ceramics, combinations
thereof, and the like, or other suitable material. Some examples of
suitable metals and metal alloys include stainless steel, such as
444V, 444L, and 314LV stainless steel; mild steel; nickel-titanium
alloy such as linear-elastic and/or super-elastic nitinol; other
nickel alloys such as nickel-chromium-molybdenum alloys (e.g., UNS:
N06625 such as INCONEL.RTM. 625, UNS: N06022 such as HASTELLOY.RTM.
C-22.RTM., TINS: N10276 such as HASTELLOY.RTM. C276.RTM., other
HASTELLOY.RTM. alloys, and the like), nickel-copper alloys (e.g.,
UNS: N04400 such as MONEL.RTM. 400, NICKELVAC.RTM. 400,
NICORROS.RTM. 400, and the like), nickel-cobalt-chromium-molybdenum
alloys (e.g., UNS: R44035 such as MP35-N.RTM. and the like),
nickel-molybdenum alloys (e.g., UNS: N10665 such as HASTELLOY.RTM.
ALLOY B2.RTM.), other nickel-chromium alloys, other
nickel-molybdenum alloys, other nickel-cobalt alloys, other
nickel-iron alloys, other nickel-copper alloys, other
nickel-tungsten or tungsten alloys, and the like; cobalt-chromium
alloys; cobalt-chromium-molybdenum alloys (e.g., UNS: R44003 such
as ELGILOY.RTM., PHYNOX.RTM., and the like); platinum enriched
stainless steel; titanium; platinum; palladium; gold; combinations
thereof; and the like; or any other suitable material.
[0101] As alluded to herein, within the family of commercially
available nickel-titanium or nitinol alloys, is a category
designated "linear elastic" or "non-super-elastic" which, although
may be similar in chemistry to conventional shape memory and super
elastic varieties, may exhibit distinct and useful mechanical
properties. Linear elastic and/or non-super-elastic nitinol may be
distinguished from super elastic nitinol in that the linear elastic
and/or non-super-elastic nitinol does not display a substantial
"superelastic plateau" or "flag region" in its stress/strain curve
like super elastic nitinol does. Instead, in the linear elastic
and/or non-super-elastic nitinol, as recoverable strain increases,
the stress continues to increase in a substantially linear, or a
somewhat, but not necessarily entirely linear relationship until
plastic deformation begins or at least in a relationship that is
more linear than the super elastic plateau and/or flag region that
may be seen with super elastic nitinol. Thus, for the purposes of
this disclosure linear elastic and/or non-super-elastic nitinol may
also be termed "substantially" linear elastic and/or
non-super-elastic nitinol.
[0102] In some cases, linear elastic and/or non-super-elastic
nitinol may also be distinguishable from super elastic nitinol in
that linear elastic and/or non-super-elastic nitinol may accept up
to about 2-5% strain while remaining substantially elastic (e.g.,
before plastically deforming) whereas super elastic nitinol may
accept up to about 8% strain before plastically deforming. Both of
these materials can be distinguished from other linear elastic
materials such as stainless steel (that can also be distinguished
based on its composition), which may accept only about 0.2 to 0.44
percent strain before plastically deforming.
[0103] In some embodiments, the linear elastic and/or
non-super-elastic nickel-titanium alloy is an alloy that does not
show any martensite/austenite phase changes that are detectable by
differential scanning calorimetry (DSC) and dynamic metal thermal
analysis (DMTA) analysis over a large temperature range. For
example, in some embodiments, there may be no martensite/austenite
phase changes detectable by DSC and DMTA analysis in the range of
about -60 degrees Celsius (.degree. C.) to about 120.degree. C. in
the linear elastic and/or non-super-elastic nickel-titanium alloy.
The mechanical bending properties of such material may therefore be
generally inert to the effect of temperature over this very broad
range of temperature. In some embodiments, the mechanical bending
properties of the linear elastic and/or non-super-elastic
nickel-titanium alloy at ambient or room temperature are
substantially the same as the mechanical properties at body
temperature, for example, in that they do not display a
super-elastic plateau and/or flag region. In other words, across a
broad temperature range, the linear elastic and/or
non-super-elastic nickel-titanium alloy maintains its linear
elastic and/or non-super-elastic characteristics and/or
properties.
[0104] In some embodiments, the linear elastic and/or
non-super-elastic nickel-titanium alloy may be in the range of
about 50 to about 60 weight percent nickel, with the remainder
being essentially titanium. In some embodiments, the composition is
in the range of about 54 to about 57 weight percent nickel. One
example of a suitable nickel-titanium alloy is FHP-NT alloy
commercially available from Furukawa Techno Material Co. of
Kanagawa, Japan. Other suitable materials may include ULTANIUM.TM.
(available from Neo-Metrics) and GUM METAL.TM. (available from
Toyota). In some other embodiments, a superelastic alloy, for
example a superelastic nitinol can be used to achieve desired
properties.
[0105] In at least some embodiments, portions or all of the
occlusive implant 10 (and variations, systems or components thereof
disclosed herein) may also be doped with, made of, or otherwise
include a radiopaque material. Radiopaque materials are understood
to be materials capable of producing a relatively bright image on a
fluoroscopy screen or another imaging technique during a medical
procedure. This relatively bright image aids a user in determining
the location of the occlusive implant 10 (and variations, systems
or components thereof disclosed herein). Some examples of
radiopaque materials can include, but are not limited to, gold,
platinum, palladium, tantalum, tungsten alloy, polymer material
loaded with a radiopaque filler, and the like. Additionally, other
radiopaque marker bands and/or coils may also be incorporated into
the design of the occlusive implant 10 (and variations, systems or
components thereof disclosed herein). to achieve the same
result.
[0106] In some embodiments, a degree of Magnetic Resonance Imaging
(MRI) compatibility is imparted into the occlusive implant 10 (and
variations, systems or components thereof disclosed herein). For
example, the occlusive implant 10 (and variations, systems or
components thereof disclosed herein) and/or components or portions
thereof, may be made of a material that does not substantially
distort the image and create substantial artifacts (e.g., gaps in
the image). Certain ferromagnetic materials, for example, may not
be suitable because they may create artifacts in an MRI image. The
occlusive implant 10 (and variations, systems or components
disclosed herein) or portions thereof, may also be made from a
material that the MRI machine can image. Some materials that
exhibit these characteristics include, for example, tungsten,
cobalt-chromium-molybdenum alloys (e.g., UNS: R44003 such as
ELGILOY.RTM., PHYNOX.RTM., and the like),
nickel-cobalt-chromium-molybdenum alloys (e.g., UNS: R44035 such as
MP35-N.RTM. and the like), nitinol, and the like, and others.
[0107] In some embodiments, the occlusive implant 10 (and
variations, systems or components thereof disclosed herein) and/or
portions thereof, may be made from or include a polymer or other
suitable material. Some examples of suitable polymers may include
copolymers, polyisobutylene-polyurethane, polytetrafluoroethylene
(PTFE), ethylene tetrafluoroethylene (ETFE), fluorinated ethylene
propylene (FEP), polyoxymethylene (POM, for example, DELRIN.RTM.
available from DuPont), polyether block ester, polyurethane (for
example, Polyurethane 85A), polypropylene (PP), polyvinylchloride
(PVC), polyether-ester (for example, ARNITEL.RTM. available from
DSM Engineering Plastics), ether or ester based copolymers (for
example, butylene/poly(alkylene ether) phthalate and/or other
polyester elastomers such as HYTREL.RTM. available from DuPont),
polyamide (for example, DURETHAN.RTM. available from Bayer or
CRISTAMID.RTM. available from Elf Atochem), elastomeric polyamides,
block polyamide/ethers, polyether block amide (PEBA, for example
available under the trade name PEBAX.RTM.), ethylene vinyl acetate
copolymers (EVA), silicones, polyethylene (PE), Marlex high-density
polyethylene, Marlex low-density polyethylene, linear low density
polyethylene (for example REXELL.RTM.), polyester, polybutylene
terephthalate (PBT), polyethylene terephthalate (PET),
polytrimethylene terephthalate, polyethylene naphthalate (PEN),
polyetheretherketone (PEEK), polyimide (PI), polyetherimide (PEI),
polyphenylene sulfide (PPS), polyphenylene oxide (PPO), poly
paraphenylene terephthalamide (for example, KEVLAR.RTM.),
polysulfone, nylon, nylon-12 (such as GRILAMID.RTM. available from
EMS American Grilon), perfluoro(propyl vinyl ether) (PFA), ethylene
vinyl alcohol, polyolefin, polystyrene, epoxy, polyvinylidene
chloride (PVdC), poly(styrene-b-isobutylene-b-styrene) (for
example, SIBS and/or SIBS 50A), polycarbonates, ionomers,
polyurethane silicone copolymers (for example, ElastEon.RTM. from
Aortech Biomaterials or ChronoSil.RTM. from AdvanSource
Biomaterials), biocompatible polymers, other suitable materials, or
mixtures, combinations, copolymers thereof, polymer/metal
composites, and the like. In some embodiments, the sheath can be
blended with a liquid crystal polymer (LCP). For example, the
mixture can contain up to about 6 percent LCP.
[0108] In some embodiments, the occlusive implant 10 (and
variations, systems or components thereof disclosed herein) may
include a textile material. Some examples of suitable textile
materials may include synthetic yarns that may be flat, shaped,
twisted, textured, pre-shrunk or un-shrunk. Synthetic biocompatible
yarns suitable for use in the present disclosure include, but are
not limited to, polyesters, including polyethylene terephthalate
(PET) polyesters, polypropylenes, polyethylenes, polyurethanes,
polyolefins, polyvinyls, polymethylacetates, polyamides,
naphthalene dicarboxylene derivatives, natural silk, and
polytetrafluoroethylenes. Moreover, at least one of the synthetic
yarns may be a metallic yarn or a glass or ceramic yarn or fiber.
Useful metallic yarns include those yarns made from or containing
stainless steel, platinum, gold, titanium, tantalum or a
Ni--Co--Cr-based alloy. The yarns may further include carbon, glass
or ceramic fibers. Desirably, the yarns are made from thermoplastic
materials including, but not limited to, polyesters,
polypropylenes, polyethylenes, polyurethanes, polynaphthalenes,
polytetrafluoroethylenes, and the like. The yarns may be of the
multifilament, monofilament, or spun-types. The type and denier of
the yarn chosen may be selected in a manner which forms a
biocompatible and implantable prosthesis and, more particularly, a
vascular structure having desirable properties.
[0109] In some embodiments, the occlusive implant 10 (and
variations, systems or components thereof disclosed herein) may
include and/or be treated with a suitable therapeutic agent. Some
examples of suitable therapeutic agents may include
anti-thrombogenic agents (such as heparin, heparin derivatives,
urokinase, and PPack (dextrophenylalanine proline arginine
chloromethylketone)); anti-proliferative agents (such as
enoxaparin, angiopeptin, monoclonal antibodies capable of blocking
smooth muscle cell proliferation, hirudin, and acetylsalicylic
acid); anti-inflammatory agents (such as dexamethasone,
prednisolone, corticosterone, budesonide, estrogen, sulfasalazine,
and mesalamine); antineoplastic/antiproliferative/anti-mitotic
agents (such as paclitaxel, 5-fluorouracil, cisplatin, vinblastine,
vincristine, epothilones, endostatin, angiostatin and thymidine
kinase inhibitors); anesthetic agents (such as lidocaine,
bupivacaine, and ropivacaine); anti-coagulants (such as
D-Phe-Pro-Arg chloromethyl keton, an RGD peptide-containing
compound, heparin, anti-thrombin compounds, platelet receptor
antagonists, anti-thrombin antibodies, anti-platelet receptor
antibodies, aspirin, prostaglandin inhibitors, platelet inhibitors,
and tick antiplatelet peptides); vascular cell growth promoters
(such as growth factor inhibitors, growth factor receptor
antagonists, transcriptional activators, and translational
promoters); vascular cell growth inhibitors (such as growth factor
inhibitors, growth factor receptor antagonists, transcriptional
repressors, translational repressors, replication inhibitors,
inhibitory antibodies, antibodies directed against growth factors,
bifunctional molecules consisting of a growth factor and a
cytotoxin, bifunctional molecules consisting of an antibody and a
cytotoxin); cholesterol-lowering agents; vasodilating agents; and
agents which interfere with endogenous vascoactive mechanisms.
[0110] While the discussion above is generally directed toward an
occlusive implant for use in the left atrial appendage of the
heart, the aforementioned features may also be useful in other
types of medical implants where a fabric or membrane is attached to
a frame or support structure including, but not limited to,
implants for the treatment of aneurysms (e.g., abdominal aortic
aneurysms, thoracic aortic aneurysms, etc.), replacement valve
implants (e.g., replacement heart valve implants, replacement
aortic valve implants, replacement mitral valve implants,
replacement vascular valve implants, etc.), and/or other types of
occlusive devices (e.g., atrial septal occluders, cerebral aneurysm
occluders, peripheral artery occluders, etc.). Other useful
applications of the disclosed features are also contemplated.
[0111] It should be understood that this disclosure is, in many
respects, only illustrative. Changes may be made in details,
particularly in matters of shape, size, and arrangement of steps
without exceeding the scope of the disclosure. This may include, to
the extent that it is appropriate, the use of any of the features
of one example embodiment being used in other embodiments. The
disclosure's scope is, of course, defined in the language in which
the appended claims are expressed.
* * * * *