U.S. patent application number 13/343550 was filed with the patent office on 2013-01-03 for variable loop snare.
This patent application is currently assigned to Merit Medical Systems, Inc.. Invention is credited to Paul Byrne, Mark Flygare, Fred Lampropoulos, Jim Mottola.
Application Number | 20130006261 13/343550 |
Document ID | / |
Family ID | 46457697 |
Filed Date | 2013-01-03 |
United States Patent
Application |
20130006261 |
Kind Code |
A1 |
Lampropoulos; Fred ; et
al. |
January 3, 2013 |
Variable Loop Snare
Abstract
A snare device comprising a variable size loop is described. The
snare loop may be configured with generally straight portions and
generally arcuate portions which correlate to maintain the general
shape of the snare loop as it is deployed or retracted. The snare
loop may additionally be configured for use in connection with an
elongate sheath.
Inventors: |
Lampropoulos; Fred; (Salt
Lake City, UT) ; Mottola; Jim; (Salt Lake City,
UT) ; Flygare; Mark; (Farmington, UT) ; Byrne;
Paul; (Tuam, IE) |
Assignee: |
Merit Medical Systems, Inc.
South Jordan
UT
|
Family ID: |
46457697 |
Appl. No.: |
13/343550 |
Filed: |
January 4, 2012 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61429691 |
Jan 4, 2011 |
|
|
|
Current U.S.
Class: |
606/113 |
Current CPC
Class: |
A61B 17/32056 20130101;
A61B 2017/00358 20130101; A61B 17/50 20130101; A61B 17/221
20130101; A61B 2017/22035 20130101; F04C 2270/0421 20130101 |
Class at
Publication: |
606/113 |
International
Class: |
A61B 17/132 20060101
A61B017/132 |
Claims
1. A snare device comprising: an elongate shaft, having a proximal
end and a distal end; and a snare loop coupled to the distal end of
the elongate shaft, the snare loop comprising: a first leg, having
a proximal end and a distal end, the proximal end coupled the
distal end of the elongate shaft; a second leg having a proximal
end and a distal end, the proximal end coupled the distal end of
the elongate shaft; and a bridge segment coupled to and between the
distal end of the first leg and the distal end of the second leg;
wherein the snare loop is configured to form an open loop when
unconstrained, and the general shape of the open loop is the same
whether the snare loop is fully unconstrained or partially
constrained.
2. The snare device of claim 1, wherein the snare loop has the same
general shape whether the snare loop is unconstrained or a proximal
portion of the first leg is constrained to be disposed
substantially adjacent a proximal portion of the second leg.
3. The snare device of claim 1, wherein the first leg and the
second leg form two adjacent legs of a generally triangular shape
when the first and second legs are unconstrained.
4. The snare device of claim 3, wherein the bridge segment forms a
generally arcuate shape.
5. The snare device of claim 1, wherein unconstrained portions of
the first leg and the second leg form two adjacent legs of a
generally triangular shape when a proximal portion of the first leg
is constrained to be disposed substantially adjacent a proximal
portion of the second leg.
6. The snare device of claim 1, further comprising an elongate
sheath member, the sheath member comprising a proximal end, a
distal end, a lumen disposed between the proximal and distal ends
of the sheath member, and a distal opening in communication with
the lumen, wherein the elongate shaft is disposed within the
lumen.
7. The snare device of claim 6, wherein the snare loop forms a
first open loop when fully deployed from the sheath member and a
second open loop when partially deployed from the sheath member,
and wherein the first open loop and the second open loop have the
same general shape.
8. The snare device of claim 1, wherein the snare loop is disposed
in a different plane than the elongate shaft member when the snare
loop and elongate shaft member are unconstrained.
9. The snare device of claim 1, wherein the snare loop is comprised
of a shape memory alloy.
10. A snare device comprising: an elongate shaft, having a proximal
end and a distal end; and a snare loop coupled to the distal end of
the elongate shaft, the snare loop comprising: a first leg, having
a proximal end and a distal end, the proximal end coupled the
distal end of the elongate shaft; a second leg having a proximal
end and a distal end, the proximal end coupled the distal end of
the elongate shaft; and an arcuate bridge segment coupled to and
between the distal end of the first leg and the distal end of the
second leg; wherein the first leg and the second leg form two
adjacent legs of a generally triangular shape when the first and
second legs are unconstrained; and an elongate sheath member, the
sheath member comprising a proximal end, a distal end, a lumen
disposed between the proximal and distal ends of the sheath member,
and a distal opening in communication with the lumen, wherein the
elongate shaft is disposed within the lumen.
11. The snare device of claim 10, wherein the snare loop is
configured to form an open loop when unconstrained, and the general
shape of the open loop is the same whether the snare loop is fully
unconstrained or partially constrained.
12. The snare device of claim 10, wherein the snare loop has the
same general shape whether the snare loop is unconstrained or a
proximal portion of the first leg is constrained to be disposed
substantially adjacent a proximal portion of the second leg.
13. The snare device of claim 10, wherein unconstrained portions of
the first leg and the second leg form two adjacent legs of a
generally triangular shape when a proximal portion of the first leg
is constrained to be disposed substantially adjacent a proximal
portion of the second leg.
14. The snare device of claim 13, wherein the snare loop forms a
first open loop when fully deployed from the sheath member and a
second open loop when partially deployed from the sheath member,
and wherein the first open loop and the second open loop have the
same general shape.
15. The snare device of claim 10, wherein the snare loop is
disposed in a different plane than the elongate shaft member when
the snare loop and elongate shaft member are unconstrained.
16. The snare device of claim 10, wherein the snare loop is
comprised of a shape memory alloy.
17. A method of deploying a snare device comprising: obtaining a
snare device comprising: an elongate shaft with a snare loop at an
end of the shaft, the elongate shaft disposed within a lumen of an
elongate sheath member; inserting the snare device into a body
lumen of a patient; and partially deploying the snare loop from a
distal opening in the sheath member, such that the snare loop has
the same general shape regardless of the degree to which the snare
loop is deployed.
18. The method of claim 17, further comprising fully deploying the
snare loop such that the snare loop forms a first loop when
partially deployed and a second loop when fully deployed such that
the first loop has the same general shape as the second loop.
19. The method of claim 17, wherein a deployed portion of the first
leg and a deployed portion of the second leg form two adjacent legs
of a generally triangular shape.
20. The method of claim 17, further comprising: adjusting a loop
size based on the therapy to be performed or a size of the body
lumen.
Description
RELATED APPLICATIONS
[0001] This application claims priority to U.S. Provisional
Application No. 61/429,691, filed on Jan. 4, 2011, and titled
"Variable Loop Snare," which is hereby incorporated by reference in
its entirety.
TECHNICAL FIELD
[0002] The present disclosure relates generally to medical devices
configured for use within the human body. Specifically, the present
disclosure relates to a snare device comprising a loop configured
to adjust to one or more sizes.
BRIEF DESCRIPTION OF THE DRAWINGS
[0003] The embodiments disclosed herein will become more fully
apparent from the following description and appended claims, taken
in conjunction with the accompanying drawings. These drawings
depict only typical embodiments, which will be described with
additional specificity and detail through use of the accompanying
drawings in which:
[0004] FIG. 1A is a perspective view of a variable loop snare
device.
[0005] FIG. 1B is a perspective view of the snare device of FIG.
1A, oriented to show the position of the snare loop relative to the
elongate shaft.
[0006] FIG. 2A is a partial cut-away view of another embodiment of
a variable loop snare device in a first configuration.
[0007] FIG. 2B is a partial cut-away view of the snare device of
FIG. 2A in a second configuration.
[0008] FIG. 3A is a side view of another embodiment of a snare
device, in a first configuration, disposed within a cross-sectional
view of a body lumen.
[0009] FIG. 3B is a side view of the snare device of FIG. 3A, in a
second configuration, disposed within a cross-sectional view of the
body lumen of FIG. 3A.
[0010] FIG. 3C is a side view of the snare device of FIGS. 3A and
3B, in a third configuration, disposed within a cross-sectional
view of the body lumen of FIGS. 3A and 3B.
DETAILED DESCRIPTION
[0011] Snares may be utilized as part of certain therapies,
including minimally invasive therapies. For instance, a snare may
be used to capture a foreign object located within a body lumen,
such as within the vasculature. Snares of various sizes may be
utilized depending on, for example, the type or nature of the
therapy, the location of the therapy within the body, and so on. As
further described below, the present disclosure relates to snare
loops which may be configured to be disposed such that a single
loop is capable of assuming a variety of sizes.
[0012] In some instances a variable size snare loop may simply
certain medical procedures or therapies by allowing a practitioner
to resize the snare loop without completely removing the snare
device and inserting an alternate snare device. For example, when
utilizing a variable loop snare a practitioner may simply resize a
variable snare loop--larger or smaller--during the course of the
procedure; obviating the need to withdraw the snare loop and
associated shaft and replace it with a snare loop of a different
size.
[0013] It will be readily understood with the aid of the present
disclosure that the components of the embodiments, as generally
described and illustrated in the figures herein, could be arranged
and designed in a variety of configurations. Thus, the following
more detailed description of various embodiments, as represented in
the figures, is not intended to limit the scope of the disclosure,
but is merely representative of various embodiments. While the
various aspects of the embodiments are presented in drawings, the
drawings are not necessarily drawn to scale unless specifically
indicated.
[0014] As used herein a "snare device" generally refers to an
elongate instrument comprising a snare loop. Snare devices, as
described herein, may further include additional components, such
as an outer sheath, for example, though these components are not
required. Additionally, a "snare loop" need not be arcuate or
circular in shape, but may be any shape enclosed by a loop a
material, for example by a wire.
[0015] Furthermore, snare loops described as having the same
"general shape," refer to loops which enclose similar, though not
necessarily identical, shapes regardless of the size of the shape.
Thus, a snare loop of any shape may be scaled up or down and still
be described as having the same "general shape" as the original
snare loop. Moreover, two loops of different sizes may have the
same "general shape" notwithstanding minor changes or variations in
the shape, disposition, orientation, or proportion of the snare
loops as they are scaled up or down. For example, a loop comprising
two substantially straight portions joined by a substantially
arcuate portion may be described as having the same general shape
as a larger or smaller version of the loop in which the straight
portions comprise a greater or lesser proportion of the entire
loop, as compared to the proportions of the original loop.
Additionally, in some instances, "scaling up" or "scaling down" the
loop size may result in loops which enclose relatively larger or
smaller areas, respectively.
[0016] The phrases "connected to," "coupled to," and "in
communication with" refer to any form of interaction between two or
more entities, including mechanical, electrical, magnetic,
electromagnetic, fluid, and thermal interaction. Two components may
be coupled to each other even though they are not in direct contact
with each other. For example, two components may be coupled to each
other through an intermediate component.
[0017] The terms "proximal" and "distal" refer to opposite ends of
a medical device. As used herein, the proximal end of a medical
device is the end nearest a practitioner during use, while the
distal end is the opposite end. For example, the proximal end of a
snare device refers to the end nearest the practitioner when the
snare device is in use.
[0018] FIG. 1A is a perspective view of a variable loop snare
device 100. In this exemplary embodiment, the snare device 100
comprises an elongate shaft 110 disposed within an outer sheath
120. The elongate shaft 110 has a distal end 114 and a proximal end
112, one or both of which may extend from the outer sheath 120. As
shown in the illustrated embodiment, the outer sheath 120 may
comprise a lumen 128, and the elongate shaft 110 may be disposed
with the lumen 128. In the illustrated embodiment, the proximal end
112 of the elongate shaft 110 extends from the proximal end 122 of
the outer sheath 120, while the distal end 114 of the elongate
shaft 110 is disposed within the lumen 128 of the outer sheath 120.
The elongate shaft 110 may be longitudinally displaceable within
the lumen 128 of the outer sheath 120, allowing, for example, the
distal end 114 of the elongate shaft 110 to be displaced such that
it extends from the distal end 124 of the outer sheath 120. The
outer sheath 120 may further include a distal opening 125 in
communication with the lumen 128 of the outer sheath 120. In some
embodiments the distal opening 125 may be disposed at the distal
end 124 of the outer sheath 120, while in other embodiments it may
be disposed through a sidewall of the outer sheath 120 at a
location adjacent the distal end 124. The elongate shaft 110 may be
configured to extend from the distal opening 125 in some
configurations.
[0019] A snare loop 130 may be coupled to the distal end 114 of the
elongate shaft 110. In the illustrated embodiment, the snare loop
130 is deployed from--meaning it is positioned such that it extends
from--the distal opening 125 of the outer sheath 120. The snare
loop 130 shown in the illustrated embodiment may be subdivided into
a first leg 140, a second leg 150, and a bridge member 160. These
component subdivisions may refer to different portions of a
integrally formed loop, or may be separate elements coupled
together to form the snare loop 130.
[0020] The legs 140, 150 may define proximal 142, 152 and distal
144, 154 ends and may be disposed between the bridge member 160 and
the elongate shaft 110. In some embodiments the proximal ends 142,
152 of each leg 140, 150 may be coupled to the elongate shaft
member 110 at its distal end 114.
[0021] In some embodiments, each leg 140, 150 may form
substantially straight portions of the snare loop 130. The bridge
member 160 may extend between the two substantially straight legs
140, 150 in a rounded or generally arcuate shape.
[0022] The snare loop 130 may be configured such that it has the
same general shape whether it is fully or partially deployed from
the outer sheath 120. For example, as shown by the arrow, and
indicated by the dashed loop 130a, when the elongate shaft 110 is
displaced in a proximal direction with respect to the outer sheath
120, portions of the snare loop 130 may be drawn into the outer
sheath 120 through the distal opening 125. As the snare loop 130 is
drawn into the outer sheath 120, the snare loop 130 may decrease in
size, though it may retain its same general shape. For example, in
the illustrated embodiment, both the snare loop 130 in the fully
deployed position and the snare loop 130a illustrated in a
partially deployed position, have substantially straight portions
(e.g. legs 140, 150) extending from the distal opening 128 which
are coupled to each other via a generally arcuate portion (e.g.
bridge member 160).
[0023] In some embodiments, portions of the snare loop 130 which
are rounded or arcuate when the snare loop 130 is fully deployed
may become substantially straight as the snare loop 130 is drawn
into the outer sheath 120. For example, the substantially straight
portions of the partially deployed snare loop 130a may be portions
of material which were arcuate when the snare loop was fully
deployed, as illustrated by element 130. Similarly, as the
partially deployed snare loop 130a is displaced distally with
respect to the outer sheath 120, substantially straight portions
may become arcuate. Thus, as referenced herein, the first leg 140,
the second leg 150, and the bridge member 160 refer to the two
straight portions and the arcuate portion of the snare loop 130,
respectively; the same segment of material may be classified as
either part of a leg portion or part of the bridge member depending
on the position and disposition of the segment when the snare loop
130 is in a particular state of deployment. Additionally, any
portion of the snare loop 130 constrained within the lumen 128 of
the outer sheath 120 is referred to as a portion of either the
first 140 or second 150 legs, notwithstanding it may not be
positioned in a substantially straight line with the deployed
portion of its respective leg.
[0024] Though in the embodiment of FIG. 1A, the legs 140, 150 and
other portions of the snare loop 130 may be constrained from
radially expanding as the snare loop 130 is drawn into the outer
sheath 120, the shape and characteristics of the snare loop 130 may
not be dependent on the outer sheath 120. In other words, whether
the snare loop 130 is partially or totally constrained by an outer
sheath 120 or by some other device, mechanism, or force, the snare
loop 130 may still exhibit the characteristics and features
described above.
[0025] FIG. 1B is another perspective view of the snare device of
FIG. 1A, oriented to show the position of the snare loop relative
to the elongate shaft. In some embodiments, the snare loop 130 may
be configured such that it does not lie in the same plane as the
longitudinal axis of the outer sheath 120 when the snare loop 130
is deployed. In other embodiments the snare loop 130 may form a
greater or smaller angle with respect to the axis of the outer
sheath 120 as compared to the embodiment illustrated in FIG. 1B. In
certain embodiments, the snare loop 130 may be in the same plane as
the longitudinal axis of the outer sheath 120, when the snare loop
130 is deployed.
[0026] Referring to both FIGS. 1A and 1B, in some embodiments the
shape and disposition of the snare loop 130 may be controlled by
forming the snare loop 130 from a shape memory alloy. In some
embodiments, the snare loop 130 may be formed of nitinol. In other
embodiments, the snare loop 130 may be formed in a particular shape
or orientation, though it is not necessarily comprised of a shape
memory or super elastic material.
[0027] FIG. 2A is a partial cut-away view of another embodiment of
a variable loop snare device that can, in certain respects,
resemble components of the snare device described in connection
with FIGS. 1A and 1B above. It will be appreciated that all the
illustrated embodiments may have analogous features. Accordingly,
like features are designated with like reference numerals, with the
leading digits incremented to "2." (For instance, the snare device
is designated "100" in FIG. 1A, and an analogous snare device is
designated as "200" in FIG. 2A.) Relevant disclosure set forth
above regarding similarly identified features thus may not be
repeated hereafter. Moreover, specific features of the snare device
and related components shown in FIG. 2A may not be shown or
identified by a reference numeral in the drawings or specifically
discussed in the written description that follows. However, such
features may clearly be the same, or substantially the same, as
features depicted in other embodiments and/or described with
respect to such embodiments. Accordingly, the relevant descriptions
of such features apply equally to the features of the snare device
of FIG. 2A. Any suitable combination of the features, and
variations of the same, described with respect to the snare device
and components illustrated in FIGS. 1A and 1B, can be employed with
the snare device and components of FIG. 2A, and vice versa. This
pattern of disclosure applies equally to further embodiments
depicted in subsequent figures and described hereafter.
[0028] FIG. 2A is a partial cut-away view of another embodiment of
a variable loop snare device 200 in a first configuration. In the
configuration illustrated in FIG. 2A, the snare loop 230 is
substantially fully deployed from the outer sheath 220. By
comparison, FIG. 2B is a partial cut-away view of the snare device
200 of FIG. 2A is a second configuration. In the configuration of
FIG. 2B, the snare loop 230 is partially retracted into the outer
sheath 220 through the distal opening 225. The arrow in FIG. 2A
indicates how longitudinal displacement of the elongate shaft 210
in a proximal direction may retract the snare loop 230 through the
distal opening 225, enabling a practitioner to transition the snare
device 220 from the configuration of FIG. 2A to the configuration
of FIG. 2B.
[0029] The snare loop 230 of FIGS. 2A and 2B comprises a first leg
240, a second leg 250, and a bridge member 260. As described above,
the legs 240, 250 refer to substantially straight portions of the
loop which extend from the distal opening 225 of the outer sheath
220. Further, portions of the snare loop 230 which are disposed
within the outer sheath 220 (for example, proximal portions 245,
255 of FIG. 2B) when the snare loop 230 is partially deployed are
also referred to as portions of the first 240 and second 250 leg,
respectively. Also as described above, in some instances, portions
of the material comprising the snare loop 230 may be substantially
straight (and thus classified as part of the legs) in some
configurations of deployment, while the same segment of material
may comprise a portion of the bridge segment (if it is generally
arcuate in shape) in other configurations or positions of
deployment. Further, any disclosure, related in connection with any
embodiment, which describes the relative disposition and
relationship of components of the snare device as the elongate
shaft is displaced proximally, to scale down the snare loop size
(or to retract the loop), is analogously applicable to the
relationship and disposition of the components as the shaft is
moved distally to scale up (or deploy), the snare loop. Similarly,
disclosure relative to retracting the snare loop may analogously
apply the reverse process of deploying the snare loop.
[0030] As illustrated in FIGS. 2A and 2B, the first 240 and second
250 legs may form to adjacent legs of a substantially triangular
shape disposed, in some embodiments, adjacent the distal opening
225 in the outer sheath 220. Lines .alpha. (alpha) and .beta.
(beta) illustrate how the legs can be understood as forming two
adjacent legs of these generally triangular shapes. In some
embodiments, as the snare loop 230 is drawn into the outer sheath
220, generally arcuate portions of the bridge member 260 may
transition and become substantially straight portions of the legs
240, 250, then be drawn into the outer sheath 220. As the legs 240,
250 are drawn into the outer sheath 220, proximal portions of each
leg 245, 255 may be constrained to lie substantially adjacent
within the outer sheath 220.
[0031] The generally triangular portion formed, in part, by the
legs 240, 250, may form a transition portion of the snare loop 230,
which may enable the snare loop 230 to maintain a generally open
configuration--in some embodiments maintaining substantially the
same general shape--as the snare loop 230 is drawn into, or
deployed from, the outer sheath 220. For example, the substantially
straight legs 240, 250 may form a transition portion near the
distal opening 225 which limits the extent to which the bridge
segment 260 of the snare loop 230 collapses, or deforms into an
elongate shape when the snare loop 230 is retracted or
deployed.
[0032] In the illustrated embodiment, both legs 240, 250 are
coupled to a single elongate shaft 210. In another embodiment, two
separate elongate shafts may be utilized, with a first elongate
shaft coupled to the first leg 240 and a second elongate shaft
coupled to the second leg 250. The use of two elongate shafts could
allow a practitioner to displace both legs 240, 250 simultaneously
or to displace one with respect to the other (i.e. pull one leg of
the snare loop but not the other) to further control the size and
shape of the snare loop.
[0033] FIGS. 3A-3C are side views of a snare device 300, in three
configurations, disposed within a cross-sectional view of a body
lumen 50. These figures illustrate an exemplary procedure that may
be performed utilizing a variable loop snare device, such as snare
device 300. FIG. 3A illustrates how a practitioner may deploy the
snare loop 330 of the snare device 300 based on the parameters of
the therapy. For example, the practitioner may attempt to capture a
fragment 70 using the snare loop 330. Thus, the practitioner may
displace the elongate shaft 310 is a distal direction with respect
to the outer sheath 320 until the snare loop 330 is deployed such
that it forms a loop having a desired size. The practitioner may
then attempt to capture the fragment 70. At any point during the
therapy the practitioner may adjust the size of the snare loop 330,
larger or smaller, by displacing the elongate shaft 310 distally or
proximally, depending on the parameters of the therapy.
[0034] FIG. 3B illustrates how the fragment 70 may be enclosed by
the snare loop 330 during therapy. Again, the practitioner may size
and resize the snare loop 330 during the process in order to
facilitate enclosure of the fragment by the snare loop 330. FIG. 3C
then illustrates how, in the exemplary procedure, the elongate
shaft 310 may be displaced proximally with respect to the outer
sheath 320 to close down the snare loop 330 and capture the
fragment 70. Notwithstanding this specific example, snare devices
as described herein may be used in any therapy which may utilize a
snare loop, for example, cutting material (such as polyps),
removing or repositioning stents or other implantable devices,
capturing fragments, and so on.
[0035] The examples and embodiments disclosed herein are to be
construed as merely illustrative and exemplary, and not a
limitation of the scope of the present disclosure in any way. It
will be apparent to those having skill in the art, with the aid of
the present disclosure, that changes may be made to the details of
the above-described embodiments without departing from the
underlying principles of the disclosure herein. It is intended that
the scope of the invention be defined by the claims appended hereto
and their equivalents.
* * * * *