U.S. patent application number 17/061025 was filed with the patent office on 2021-01-21 for catheter.
This patent application is currently assigned to Teleflex Life Sciences Limited. The applicant listed for this patent is Teleflex Life Sciences Limited. Invention is credited to John Bridgeman, Karl V. Ganske, Steve Michael, Howard C. Root, Gregg S. Sutton.
Application Number | 20210015517 17/061025 |
Document ID | / |
Family ID | 1000005123604 |
Filed Date | 2021-01-21 |
United States Patent
Application |
20210015517 |
Kind Code |
A1 |
Root; Howard C. ; et
al. |
January 21, 2021 |
CATHETER
Abstract
Catheters and methods for supporting a guidewire or delivering a
radiopaque, diagnostic or therapeutic agent through a vessel
stenosis or other tortuous anatomy are disclosed. A catheter can
comprise an elongate shaft body and a tip member disposed at a
distal end of the shaft body. The shaft body can extend from a
proximal end to the distal end and can define an inner lumen. The
shaft body can include a liner, a braid member surrounding the
liner, a multi-layer coil surrounding the braid member, and a
polymer cover surrounding the multi-layer coil. The multi-layer
coil can include first and second coil layers wound in opposing
directions. An outer surface portion of the polymer cover can
include one or more helical threads. The tip member can be made
from a metal or a polymer and can also include one or more helical
threads around its outer surface.
Inventors: |
Root; Howard C.; (Excelsior,
MN) ; Bridgeman; John; (Minneapolis, MN) ;
Michael; Steve; (Maple Grove, MN) ; Sutton; Gregg
S.; (Orono, MN) ; Ganske; Karl V.; (Edina,
MN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Teleflex Life Sciences Limited |
Valletta |
|
MT |
|
|
Assignee: |
Teleflex Life Sciences
Limited
Valletta
MT
|
Family ID: |
1000005123604 |
Appl. No.: |
17/061025 |
Filed: |
October 1, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
15441352 |
Feb 24, 2017 |
10835283 |
|
|
17061025 |
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|
14673966 |
Mar 31, 2015 |
9636477 |
|
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15441352 |
|
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|
62061781 |
Oct 9, 2014 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61M 2025/006 20130101;
A61M 25/0045 20130101; A61B 17/320758 20130101; A61M 25/0105
20130101; A61M 25/0043 20130101; A61M 25/005 20130101 |
International
Class: |
A61B 17/3207 20060101
A61B017/3207; A61M 25/00 20060101 A61M025/00; A61M 25/01 20060101
A61M025/01 |
Claims
1. A catheter, comprising: an elongate shaft body extending from a
proximal end to a distal end and defining an inner lumen, the shaft
body including a liner, a braid member and a coil member
surrounding at least a portion of the liner, and an outer polymer
cover; and a tip member disposed at the distal end of the shaft
body, wherein a distal end of the liner and the coil member extend
beyond the distal end of the shaft body and into a proximal end of
the tip member.
2. The catheter of claim 1, wherein the coil member includes one or
more helically wound elongate strands composed of a same material
composition at each of the proximal end of the shaft body, the
distal end of the shaft body, and the proximal end of the tip
member.
3. The catheter of claim 1, wherein the coil member includes one or
more helically wound elongate strands having a cross-sectional size
that is the same at each of the proximal end of the shaft body, the
distal end of the shaft body, and the proximal end of the tip
member.
4. The catheter of claim 1, wherein the coil member incudes
multiple elongate strands having a fully-round transverse
profile.
5. The catheter of claim 1, wherein the coil member surrounds the
braid member.
6. The catheter of claim 1, wherein the braid member includes a
plurality of interbraided, metallic elongate strands along its
length that form multiple strand crossings.
7. The catheter of claim 6, wherein the elongate strands are
axially spaced apart to define multiple pics.
8. The catheter of claim 1, wherein the braid member includes a
plurality of elongate strands wound helically in opposite
directions.
9. The catheter of claim 1, wherein a distal end of the braid
member extends beyond the distal end of the shaft body.
10. The catheter of claim 1, wherein the braid member includes a
plurality of elongate strands having a rectangular transverse
profile.
11. The catheter of claim 10, wherein the rectangular transverse
profile includes a thickness directed radially, the thickness being
in the range of 0.010 mm to 0.015 mm, inclusive.
12. The catheter of claim 1, wherein a proximal portion of the
shaft body is configured to be less flexible than a distal portion
of the shaft body.
13. The catheter of claim 1, wherein the tip member includes a
polymer tip member.
14. The catheter of claim 1, wherein the tip member includes a
non-tapered proximal portion and a tapered distal portion.
15. The catheter of claim 1, wherein a boundary marking the distal
end of the shaft body and a proximal end of the tip member is
defined by a change in radiopacity, the change in radiopacity due
to a material of the tip member having greater radiopacity than any
material proximal of the tip member.
16. The catheter of claim 1, wherein the tip member comprises a
smooth outer surface and has increased flexibility relative to the
shaft body.
17. The catheter of claim 1, wherein the inner lumen has a constant
diameter that extends from the proximal end of the shaft body to
the distal end of the shaft body.
18. The catheter of claim 1, wherein the tip member includes a
lumen that is coaxial with the inner lumen.
19. The catheter of claim 18, wherein the inner lumen and the lumen
are configured to receive a guidewire.
20. The catheter of claim 1, wherein the proximal end of the shaft
body is configured to connect to a luer hub.
Description
CLAIM OF PRIORITY
[0001] This non-provisional patent document is a continuation of
U.S. patent application Ser. No. 15/441,352, filed on Feb. 24,
2017, which is a divisional of U.S. patent application Ser. No.
14/673,966, filed on Mar. 31, 2015, now issued under U.S. Pat. No.
9,636,477, which claims the benefit of priority under 35 U.S.C.
.sctn. 119(e) to U.S. Provisional Patent Application Ser. No.
62/061,781, entitled "CATHETER," filed on Oct. 9, 2014, each of
which is herein incorporated by reference in its entirety.
TECHNICAL FIELD
[0002] The subject matter of this patent document relates to the
field of medical devices. More particularly, but not by way of
limitation, the subject matter relates to catheters and methods for
supporting a guidewire or delivering a radiopaque, diagnostic or
therapeutic agent.
BACKGROUND
[0003] A variety of catheters exist for percutaneous insertion into
a subject's vascular system to accomplish diagnostic or therapeutic
objectives using the Seldinger technique. As part of the Seldinger
technique, a guidewire can be inserted through the lumen of a
hollow needle and made to enter the vascular system. A catheter can
fit over and slide along the guidewire as it passes through
vasculature. The guidewire alone or with the help of the catheter
can be incrementally maneuvered through the vasculature to a target
site.
[0004] Catheters are typically introduced through a large artery,
such as those found her the groin or neck, and then passed through
ever-narrower regions of the vascular system until reaching the
target site. Often, such pathways will wind back upon themselves in
a multi-looped path. The quest to provide treatment options for
narrowing and winding vessels and other lumens has given rise to
the need to reduce catheter size, yet retain a catheter's favorable
structural properties.
OVERVIEW
[0005] Various structural properties can be used to describe
catheters. "Pushability," for example, can be used to describe a
catheter's axial strength to facilitate movement of its distal end
through vascular passages or other body lumens by applying an axial
pushing force near its proximal end. A related characteristic,
"torqueability," can be used to describe the ability to rotate the
catheter's distal end by rotating its proximal end. "Flexibility,"
particularly along a distal portion of the catheter, becomes
increasingly important as the catheter enters winding or tortuous
passages. Another characteristic that becomes more important with
increased curvature of passages is the ability to resist
kinking.
[0006] The present inventors recognize a difficulty in placing
existing "push-to-advance" catheter designs, which include a
relatively stiff, thick wall to navigate a vascular passage. The
present inventors further recognize that as higher demands for
length have been placed on catheters, a competing difficulty of
smaller catheter distal end portions has developed.
[0007] The present catheters overcome drawbacks of existing
catheter designs by providing a structure that, despite a reduction
in distal diameter, maintains favorable structural properties and
advanceability along its length. A catheter can comprise an
elongate shaft body and a tip member disposed at a distal end of
the shaft body. The shaft body can extend from a proximal end to
the distal end and can define an inner lumen. The shaft body can
include a liner, a braid member surrounding the liner, a
multi-layer coil surrounding the braid member, and a polymer cover
surrounding the multi-layer coil. The multi-layer coil can include
first and second coil layers wound in opposing directions. An outer
surface portion of the polymer cover can include one or more
helical threads. In an example, the one or more helical threads are
positioned around a distal end portion of the shaft body and have a
radial height sufficient to provide a longitudinal pull on a vessel
wall or a stenosis when rotated.
[0008] The tip member can be made from a metal or a polymer and can
also include one or more helical threads around its outer surface.
Clinical bench testing has demonstrated that the present catheters
exhibit pushability, flexibility, an ability to transfer torque in
a controllable manner without kinking, and an ability to be
propelled along a blood vessel, particularly when rotated.
[0009] The present methods can include advancing a distal end of a
guidewire to a location proximate a stenosis or other narrowing in
a blood vessel; guiding a catheter over the guidewire; using the
guidewire as a rail, advancing a distal end of the catheter to the
location proximate the stenosis or narrowing; rotating the catheter
in a first direction and advancing it into the stenosis or
narrowing; and advancing the guidewire through the stenosis or
narrowing with the support of the catheter. The guidewire can be
inserted into an inner lumen of the catheter, where the inner lumen
is defined, in part, by a liner, a braid member surrounding the
liner, a multi-layer coil surrounding the braid member, and a
polymer cover surrounding the multi-layer coil. Rotation of the
catheter in the first direction can engage one or more helical
threads on an outer surface of the polymer cover with the stenosis
or wall of the blood vessel, which can help advance the catheter
into and eventually through the stenosis or narrowing.
[0010] These and other examples and features of the present
catheters and methods will be set forth, at least in part, in the
following Detailed Description. This
[0011] Overview is intended to provide non-limiting examples of the
present subject matter--it is not intended to provide an exclusive
or exhaustive explanation. The Detailed Description below is
included to provide further information about the present catheters
and methods.
BRIEF DESCRIPTION OF THE DRAWINGS
[0012] In the drawings, like numerals can be used to describe
similar features and components throughout the several views. The
drawings illustrate generally, by way of example but not by way of
limitation, various embodiments discussed in the present patent
document.
[0013] FIG. 1 illustrates a schematic view of a present catheter,
as constructed in accordance with at least one embodiment, located
in coronary vasculature.
[0014] FIG. 2 illustrates a distal end portion of a present
catheter, as constructed in accordance with at least one
embodiment, with one or more helical threads located on both an
outer surface of a shaft body and a tip member being engaged with a
vessel wall.
[0015] FIG. 3 illustrates partial, staggered cutaways of a present
catheter, as constructed in accordance with at least one
embodiment.
[0016] FIG. 4 illustrates an enlarged side view of a distal end
portion of a present catheter's shaft body, as constructed in
accordance with at least one embodiment.
[0017] FIG. 5 illustrates a metallic tip member including one or
more helical threads coupled with a distal end of a present
catheter's shaft body, as constructed in accordance with at least
one embodiment.
[0018] FIG. 6 illustrates a metallic tip member including a smooth
outer surface coupled with a distal end of a present catheter's
shaft body, as constructed in accordance with at least one
embodiment.
[0019] FIG. 7 illustrates a polymer tip member including a
non-tapered proximal portion and a tapered distal portion coupled
with a distal end of a present catheter's shaft body, as
constructed in accordance with at least one embodiment.
[0020] FIG. 8 illustrates partial, staggered cutaways of a present
catheter's shaft body, as constructed in accordance with at least
one embodiment.
[0021] FIG. 9 illustrates a cross-section of a proximal end portion
of a present catheter's shaft body, such as a cross-section along
line 9-9 of FIG. 3.
[0022] FIG. 10 illustrates a cross-section of a distal end portion
of a present catheter's shaft body, such as a cross-section along
line 10-10 of FIG. 3.
[0023] FIG. 11 illustrates a cross-section of a present catheter's
polymer tip member, such as a cross-section along line 11-11 of
FIG. 3.
[0024] FIG. 12 illustrates a method of using a present catheter to
navigate through vasculature, as constructed in accordance with at
least one embodiment.
[0025] The drawing figures are not necessarily to scale. Certain
features and components may be shown exaggerated in scale or in
schematic form and some details may not be shown in the interest of
clarity and conciseness.
DETAILED DESCRIPTION
[0026] FIG. 1 illustrates a present catheter 100 for supporting a
guidewire 102 or delivering a radiopaque, diagnostic or therapeutic
agent through a vessel stenosis or other tortuous anatomy of
coronary vasculature 104, as constructed in accordance with at
least one embodiment. The present catheter 100 can be used in
peripheral and coronary applications, but its primary benefit is
believed to be in coronary applications where the vessels, relative
to peripheral vessels, are smaller, more tortuous and more
difficult to reach.
[0027] The catheter 100 can include a shaft body 106 and a tip
member 108 and can be delivered through a surgically created
opening in a femoral or radial artery, for example. The shaft body
106 can extend from a proximal end 110 to a distal end 112 and can
define an inner lumen. The tip member 108 can be connected to the
distal end 112 of the shaft body 106 and can include a lumen
coaxial with the shaft body's inner lumen to facilitate receipt or
delivery of the guidewire or agent. A luer hub 114 can be connected
to the proximal end 110 of the shaft body 106 to facilitate
connection to other medical devices, such as valves, syringes or
adaptors, and to provide access to the shaft body's inner
lumen.
[0028] A proximal portion 116 of the shaft body 106 can be designed
to be less flexible than its distal portion 118. The less flexible
proximal portion 116 can provide enhanced axial and circumferential
strength to the catheter 100 for greater pushability and
torqueability. The distal portion 118 can provide the catheter 100
with enhanced flexibility for negotiating winding or tortuous
vascular passages. An outer surface portion of the shaft body 106,
such as the distal end portion 118, can include one or more helical
threads 120 to enhance catheter delivery or withdrawal through
rotation.
[0029] FIG. 2 illustrates engagement between a vessel wall 226 and
one or more helical threads 220, 224 projecting from outer surfaces
of a catheter's shaft body 206 and tip member 208, respectively. A
treating clinician can gently push the "rotate-to-advance" catheter
200 through vasculature far enough to engage the helical threads
220, 224 with the vessel wall 226. The clinician can then rotate a
proximal end of the catheter 200 in the direction 228 of the
helical threads, such as in a clockwise direction, to advance the
catheter through small and tortuous vessels to a target site. The
helical threads 220, 224 can have a sufficient radial height,
relative to an outer surface of the shaft body 206 or tip member
208, to provide a longitudinal pull on the vessel wall 226 or a
stenosis, if present, when rotated. The catheter 200 can be removed
by rotating the proximal end of the catheter in a direction 230
opposite the direction of delivery, such as in a counterclockwise
direction.
[0030] A side view of a catheter 300, including a shaft body 306
and a tip member 308, is illustrated in FIG. 3. The shaft body 306
can include multiple components, including an inner liner 332, a
reinforcing braid member 334, two coil layers 336, 338 wound in
opposing directions, and an outer polymer cover 340. The braid
member 334 can be composed of multiple elongate strands having a
rectangular transverse profile and arranged with its thickness
directed radially. Each coil layer 336, 338 can be composed of
multiple elongate stands having a fully-round transverse profile.
The catheter 300 can optionally include a polymer tip member 308
composed of a non-tapered proximal portion and a tapered distal
portion. The proximal portion of the tip member 308 (shown cutaway)
can receive distal ends of the braid member 334 and coil layers
336, 338. Collectively, the sandwiching of the braid member 334 and
coil layers 336, 338 between the inner liner 332 and the outer
polymer cover 340, and the polymer tip member's 308 receipt of
distal ends of the braid member 334 and the coil layers 336, 338
permits the catheter 300 to be formed at a reduced thickness while
maintaining favorable structural characteristics including
pushability, torqueability, flexibility and resistance to
kinking.
[0031] FIG. 4 illustrates, in enlarged view, one or more helical
threads 420 on an outer surface portion of a polymer cover 440,
which can help propel a catheter through a blood vessel when
rotated. The helical threads 420 can be positioned around a distal
end portion 418 of a shaft body 406 and project radially outward.
Ends 442, 444 of the helical threads 420 can be tapered from zero
to full height in one-half turn of the helix to facilitate gentle,
gradual displacement of a vessel wall or stenosis by the threads
when the catheter is rotated for advancement and retraction. Thread
width 446 and thread pitch 448 can be designed so that the vessel
wall or stenosis does not bridge between adjacent turns of the
threads 420 but rather is only displaced in a manner closely
conforming to the threads 420, thereby providing the necessary
longitudinal grip on the vessel wall or stenosis for advancing and
retracting the catheter.
[0032] In various examples, the one or more helical threads 420
include a polymer member wound around the polymer cover 440. The
polymer member can be a strip of a synthetic fiber, such as nylon
or polyester, having a fully-round cross-sectional shape of about
0.05 mm-0.2 mm in diameter prior to being bonded to the polymer
cover 440. The polymer member can have a melting temperature higher
than a melting temperature of the polymer cover 440 so that the
helical threads 420 can be thermally bonded to, and inlaid in, the
polymer cover 440. Alternatively, the helical threads 420 can be
attached to the polymer cover 440 by sonic or adhesive bonding. The
polymer member can, for example, extend 20-50 turns around the
outer surface of the polymer cover 440 at a uniform pitch of 1.0
mm-2.0 mm, resulting in a threaded section 2-8 cm in length.
Optionally, the polymer member can be reinforced with wire or
fibers.
[0033] Hard, metallic tip members or soft, polymer tip members can
be utilized by the present catheters and coupled to a distal end
112, 212, 312, 512, 612, 712, 812 of a shaft body 106, 206, 306,
506, 606, 706, 806. FIGS. 1, 2, 5 and 6 illustrate optional
metallic tip members 108, 208, 508, 608, and FIGS. 3 and 7
illustrate an optional polymer tip member 308, 708.
[0034] Metallic tip members 108, 208, 508, 608 can facilitate
crossing of a difficult stenosis or other narrowing and allow for
imaging on a screen as a catheter advances through vasculature. In
various examples, the metallic tip member 108, 208, 508, 608
includes a gold-plated, stainless steel member available with
(FIGS. 1, 2 and 5) or without (FIG. 6) one or more helical threads
224, 524. The gold-plating allows for imaging on the screen. The
helical threads 224, 524 can provide rotational advancement (in
additional to the helical threads of the shaft body) through a
vessel stenosis or other tortuous anatomy when the catheter is
rotated. In some examples, the one or more helical threads 224, 524
extend radially outward from an outer surface of the tip member
208, 508; in other examples, the helical threads extend radially
inward from the outer surface and form a helical depression.
Metallic tip members 608 including a smooth outer surface (i.e.,
without threads) can be used in treatment cases benefiting from
minimized friction during catheter advancement. In various
examples, a proximal diameter of the metallic tip members can be in
a range of 0.8 mm to 1.10 mm and a distal diameter 509, 609 can be
in a range of 0.50 mm to 0.80 mm, such as about 0.70 mm.
[0035] Polymer tip members 308, 708 can facilitate tracking through
tortuous vasculature using their inherent flexibility and low
profile, including a distal diameter 709 in a range of 0.3 mm to
0.6 mm. In the example of FIG. 7, the polymer tip member 708
includes a non-tapered proximal portion 750 and a tapered distal
portion 752. The proximal portion 750 and the distal portion 752
can have a similar length, or the proximal portion 750 can be
longer than the distal portion 752. In an example, the polymer tip
member 708 has a length of 11 mm, including a 6 mm proximal portion
750 and a 5 mm distal portion 752. The polymer tip member 708 can
be impregnated with a radiopaque filler material, such as barium
sulfate, bismuth trioxide, bismuth carbonate, powdered tungsten,
powdered tantalum or the like, so that its location within a
subject's body can be radiographically visualized.
[0036] FIG. 8 further illustrates the multiple components of a
present catheter's shaft body 806, including a liner 832, a braid
member 834, multiple coil layers 836, 838 and a polymer cover 840,
each of which can extend the length 859 of the shaft body 806. The
shaft body 806 can define an inner lumen 860 and have an inner
surface 854, an outer surface 856, and a wall thickness 858 in a
radial direction. The length 859 of the shaft body 806 can range
from 60 cm-200 cm, for example.
[0037] The liner 832 can extend the length of the shaft body 806
and, optionally, into and through the catheter's tip member. The
liner 832 can be formed of a material providing high lubricity,
such as polytetrafluoroethylene (PTFE) or polyethylene, to reduce
the forces required to advance a guidewire or other member through
an associated catheter.
[0038] Surrounding the liner 832 can be a braid member 834 formed
of multiple elongate strands 862 wound helically in opposite
directions and interbraided with one another to form multiple
crossings. The braid member 834, like the liner 832, can extend the
length of the shaft body 806 and into the catheter's tip member.
The strands 862 can be formed of stainless steel or another high
tensile strength material and can be axially spaced apart to define
multiple pies and voids 863 between the strands 862. The axial
length of the pies, as determined by the strand spacing, can be
selected to influence one or more of the catheter's pushability,
torqueability, flexibility and kink resistance properties. The
transverse profiles of the strands 862, both as to surface area and
as to the ratio of width-to-thickness, can also be selected to
influence these characteristics. For example, structural strength
can be increased by increasing the strand width while maintaining
the same thickness. Flexibility can be increased by increasing the
pic axial length. Another factor influencing the desired
characteristics is the braid angle of the filament strand windings,
i.e., the angle of each helical strand 862 with respect to a
longitudinal central axis. Increasing the braid angle tends to
increase the torqueability while reducing the pushability. In
short, strands 862 and arrangements of the strands 862 can be
selected to customize the present catheter's properties.
[0039] In the example of FIG. 8, the braid member 834 includes 16
stainless steel strands 862 having a braid angle of 45 degrees
along the axis of the catheter. Other braid angle ranges from 20
degrees to 60 degrees, for example, are also suitable. The braid
member 834 can be stretched axially as it is placed upon the liner
832 during manufacture. When the coil layers 836, 838 and the
polymer cover 840 are placed over the braid member 834, the braid
member 834 can assume an unbiased configuration. In various
examples, strands 862 of the braid member 834 can have a thickness
ranging from 0.010 mm to 0.015 mm, but both larger and smaller
strand thicknesses can also be used. Widths of the strands 862 can
also vary. Some embodiments use strand widths in the range of about
0.057 mm to 0.070 mm.
[0040] The multiple coil layers, which surround the braid member
834, can include a first coil layer 836 composed of one or more
wires 864 wound in a first direction and a second coil layer 838
composed of one or more wires 866 wound in a second direction,
opposing the first direction. The second coil layer 838 can be
positioned around and in contact with the first coil layer 836. In
use, the wires 864, 866 of the first and second coil layers 836,
838 can interlock and provide the present catheter with
bi-directional torqueability and pushability capabilities. For
example, if one wire 864, 866 in a coil layer has a tendency to
kink or bend in use, particularly under influence of a load, the
other wires 864, 866 in the same layer or the adjacent layer can
support it and inhibit kinking.
[0041] The wires 864, 866 can include a fully-rounded cross-section
and can vary in size, number and pitch between the first coil layer
836 and the second coil layer 838 to alter structural properties of
the catheter. Wire properties can be selected to balance structural
properties, such as pushability, torqueability and flexibility. In
an example, each coil layer includes 12 wires having a diameter of
about 0.050 mm. Each of the 12 wires can have a uniform pitch that
is equal to or greater than about 0.623 mm. Adjacent wires of the
12 wire grouping can be view as having a pitch that is equal to or
greater than about 0.072 mm, with a small gap distributed
throughout each 12 wire grouping. This distributed gap forms a void
865 between successive windings of each of the first and second
coil layers 836, 838. The size of the pitch can depend on the
diameter of the wires, the diameter of the inner lumen 860 and the
number of wires in the layer.
[0042] The polymer cover 840 can surround the coil layers 836, 838
and, in light of the liner 832, can form the second of two polymer
layers included in the shaft body 806. The polymer cover 840 can
include a low-friction polymer to reduce the forces required to
advance the catheter through vasculature, or a polymer with low
viscosity at melting temperatures to allow flow through and around
the voids 865 in the coil layers 836, 838 and the voids 863 in the
braid member 834 when heated during manufacture, the latter of
which is shown in different perspectives in FIGS. 8 and 9. In an
example, the polymer cover 840 is composed of polyether block amide
(commonly referred to as "PEBAX," a registered trademark of Arkema
France Corporation). The polymer cover 840 can be applied to the
coil layers 836, 838 after they are wound into a tubular shape via
an extrusion, molding or shrink tubing process, and can be applied
thicker along a proximal portion of the shaft body 806 than along a
distal portion of the shaft body to enhance distal flexibility and
provide a smaller leading size. In an example, the proximal portion
includes an outer diameter 909 (see FIG. 9) between 0.9 mm-11 mm
and the distal portion includes an outer diameter 1009 (see FIG.
10) between 0.8-1.0 mm.
[0043] A hydrophilic coating can be provided on the outer surface
856 of the shaft body 806 for lubricious delivery and to aid in
steerability. The hydrophilic coating can be thin and constitute
only a minor part of the wall thickness of the shaft body 806.
[0044] FIGS. 9 and 10 respectively illustrate cross-sections of a
proximal portion and a distal portion of a shaft body 906, 1006,
such as along lines 9-9 and 10-10 of FIG. 3. As shown, a polymer
cover 940, 1040 can extend inward and seal around first and second
coil layers 936, 938, 1036, 1038 and a braid member 934, 1034.
Inherent elasticity of the polymer cover 940, 1040 can allow wires
964, 966, 1064, 1066 of the coil layers 936, 938, 1036, 1038 to
make small movements so that the flexibility of the coil layers is
maintained; the elasticity also allows the shaft body wall to stay
leak-proof when the wires move. The polymer cover 940, 1040 can
terminate at the distal end of the shaft body 906, 1006. proximal
to a tip member.
[0045] FIG. 11 illustrates a cross-section of a proximal portion of
a tip member 1108, and specifically a polymer tip member, which is
coupled with a distal end of a shaft body. Distal ends of first and
second coil layers 1136, 1138, a braid member 1134 and a liner 1132
can extend into the tip member 1108 and can be surrounded by a
polymer impregnated with a radiopaque material. The polymer 1168 of
the tip member 1108 can have a higher viscosity at melting
temperatures such that little to no flow through or around the coil
layers 1136, 1138 or the braid member 1134 occurs. In an example,
the polymer of the tip member is pellethane and the void space 1170
existing within the polymer 1168 can provide the catheter's distal
end portion with increased flexibility relative to the shaft
body.
[0046] FIG. 12 illustrates a method 1272 of using a present
catheter to navigate through vasculature, as constructed in
accordance with at least one embodiment.
[0047] At step 1274, the method can include advancing a distal end
of a guidewire through vasculature to a location proximate a
stenosis or other narrowing in a blood vessel. At step 1276, a
catheter can be guided over the guidewire by inserting its proximal
end into an inner lumen of the catheter from the catheter's distal
end. The inner lumen can be defined, in part, by a liner, a braid
member surrounding the liner, a multi-layer coil surrounding the
braid member, and a polymer cover surrounding the multi-layer coil.
Using the guidewire as a rail, a distal end of the catheter can be
advanced to the location proximate the stenosis or narrowing at
step 1278.
[0048] The catheter can be rotated in a first direction at step
1280, thereby engaging one or more helical threads on an outer
surface of the polymer cover with the stenosis or wall of the blood
vessel. This engagement between the helical threads and the
stenosis or vessel wall can propel the catheter forward, in a
distal direction. Incremental rotation of the catheter,
particularly the catheter's proximal end, can allow incremental
movement of the catheter relative to the stenosis or vessel
wall.
[0049] At step 1282, the guidewire can be advanced distally with
the support of the catheter. The method can be configured such that
the distal end of the guidewire is at all times distal to the
distal end of the catheter.
[0050] The catheter can be withdrawn from the blood vessel at step
1284 by rotating its proximal end in a second direction, opposite
the first direction. Rotation of the catheter, whether in the first
direction or the second direction, can cause wires of the first and
second coil layers to engage.
[0051] Additional method steps are also possible. At step 1286, the
method can optionally include viewing a tip member using an imaging
means. At step 1288, the method can optionally include delivering a
radiopaque, diagnostic or therapeutic agent through the inner lumen
of the catheter. And at step 1290, the method can optionally
include exchanging the guidewire advanced to the location proximate
the stenosis or narrowing with a second guidewire.
Closing Notes
[0052] The present catheters and methods include or use a
multi-component shaft body, which can include one or more helical
threads projecting from its outer surface. The multi-component
shaft body can provide catheters with favorable structural
characteristics including pushability, torqueability, flexibility
and resistance to kinking. First and second helically-wound coil
layers of the shaft body, for example, can provide torqueability
and pushability to the catheter. A braid member can enable a small
shaft body diameter for extending through a tortuous path and
reaching small vessels and can further provide kink resistance. The
one or more helical threads can provide the catheter with a
rotationally-activated propulsion means. Accordingly, the present
catheters and methods can overcome difficulties associated with
placing existing "push-to-advance" catheter designs and can possess
a small cross-section to navigate tortuous anatomy.
[0053] The above Detailed Description includes references to the
accompanying drawings, which form a part of the Detailed
Description. The Detailed Description should be read with reference
to the drawings. The drawings show, by way of illustration,
specific embodiments in which the present catheters and methods can
be practiced. These embodiments are also referred to herein as
"examples."
[0054] The above Detailed Description is intended to be
illustrative, and not restrictive. For example, the above-described
examples (or one or more features or components thereof) can be
used in combination with each other. Other embodiments can be used,
such as by one of ordinary skill in the art upon reviewing the
above Detailed Description. Also, various features or components
can be grouped together to streamline the disclosure. This should
not be interpreted as intending that an unclaimed disclosed feature
is essential to any claim. Rather, inventive subject matter can lie
in less than all features of a particular disclosed embodiment.
Thus, the following claim examples are hereby incorporated into the
Detailed Description, with each example standing on its own as a
separate embodiment:
[0055] In Example 1, a catheter can comprise an elongate shaft body
and a tip member disposed at a distal end of the shaft body. The
shaft body can extend from a proximal end to the distal end and can
define an inner lumen. The shaft body can include a liner, a
multi-layer coil surrounding the liner, and a polymer cover
surrounding the multi-layer coil. An outer surface portion of the
polymer cover can include one or more helical threads.
[0056] In Example 2, the catheter of Example 1 can optionally be
configured such that the multi-layer coil includes a first coil
layer wound in a first direction and a second coil layer,
surrounding the first coil layer, wound in a second direction
opposing the first direction.
[0057] In Example 3, the catheter of Example 2 can optionally be
configured such that the first and second coil layers each include
a plurality of wound wires having a fully round cross-section.
[0058] In Example 4, the catheter of any one or any combination of
Examples 1-3 can optionally be configured such that the polymer
cover extends inward through voids between successive windings of
the multi-layer coil.
[0059] In Example 5, the catheter of any one or any combination of
Examples 1-4 can optionally be configured such that the shaft body
further comprises a braid member extending between the liner and
the multi-layer coil.
[0060] In Example 6, the catheter of Example 5 can optionally be
configured such that the polymer cover extends inward through voids
between successive windings of the multi-layer coil and into voids
of the braid member.
[0061] n Example 7, the catheter of any one or any combination of
Examples 5 or 6 can optionally be configured such that a distal end
of each of the liner, the braid member, and the multi-layer coil
extend beyond the distal end of the shaft body.
[0062] In Example 8, the catheter of any one or any combination of
Examples 1-7 can optionally be configured such that the one or more
helical threads are positioned around a distal end portion of the
shaft body.
[0063] In Example 9, the catheter of any one or any combination of
Examples 1-8 can optionally be configured such that the one or more
helical threads include a polymer member wound around the polymer
cover.
[0064] In Example 10, the catheter of Example 9 can optionally be
configured such that the polymer member forming the one or more
helical threads has a melting point higher than a melting point of
the polymer cover surrounding the multi-layer coil.
[0065] In Example 11, the catheter of any one or any combination of
Examples 1-9 can optionally be configured such that the one or more
helical threads include a depression of the outer surface of the
polymer cover.
[0066] In Example 12, the catheter of any one or any combination of
Examples 1-11 can optionally be configured such that the tip member
includes a metallic tip member.
[0067] In Example 13, the catheter of Example 12 can optionally be
configured such that an outer surface of the metallic tip member
includes one or more helical threads.
[0068] In Example 14, the catheter of Example 13 can optionally be
configured such that the one or more helical threads of the
metallic tip member project radially outward from its outer
surface.
[0069] In Example 15, the catheter of Example 13 can optionally be
configured such that the one or more helical threads of the
metallic tip member extend radially inward from its outer
surface.
[0070] In Example 16, the catheter of any one or any combination of
Examples 1-15 can optionally be configured such that the tip member
includes a polymer tip member.
[0071] In Example 17, the catheter of Example 16 can optionally be
configured such that the polymer tip member includes a non-tapered
proximal portion and a tapered distal portion.
[0072] In Example 18, the catheter of Example 17 can optionally be
configured such that a distal end of the multi-layer coil extends
beyond the distal end of the shaft body and into the non-tapered
proximal portion of the polymer tip member.
[0073] In Example 19, a method can comprise advancing a distal end
of a guidewire to a location proximate a stenosis or other
narrowing in a blood vessel; guiding a catheter over the guidewire;
using the guidewire as a rail, advancing a distal end of the
catheter to the location proximate the stenosis or narrowing;
rotating the catheter in a first direction and advancing it into
the stenosis or narrowing; and advancing the guidewire through the
stenosis or narrowing with the support of the catheter. The
guidewire can be inserted into an inner lumen of the catheter,
where the inner lumen is defined, in part, by a liner, a braid
member surrounding the liner, a multi-layer coil surrounding the
braid member, and a polymer cover surrounding the multi-layer coil.
Rotation of the catheter in the first direction can engage one or
more helical threads on an outer surface of the polymer cover with
the stenosis or wall of the blood vessel, which can help advance
the catheter into and eventually through the stenosis or
narrowing.
[0074] In Example 20, the method of Example 19 can optionally be
configured such that rotating the catheter in the first direction
further includes engaging one or more helical threads of a tip
member, disposed at the distal end of the catheter, with the
stenosis or wall of the blood vessel.
[0075] In Example 21, the method of any one or any combination of
Examples 19 or 20 can optionally be configured such that rotating
the catheter in the first direction includes rotating a proximal
end portion of the catheter, thereby causing the distal end of the
catheter to rotate a corresponding amount.
[0076] In Example 22, the method of any one or any combination of
Examples 19-21 can optionally further comprise rotating the
catheter in a second direction, opposite the first direction, and
withdrawing the catheter from the blood vessel.
[0077] In Example 23, the method of Example 22 can optionally be
configured such that rotating the catheter in the first or second
direction includes engaging first and second coil layers of the
multi-layer coil.
[0078] In Example 24, the method of any one or any combination of
Examples 22 or 23 can optionally be configured such that rotating
the catheter in the first or second direction includes inhibiting
kinking between a distal end of a shaft body and a proximal end of
a tip member by extending the braid member and the multi-layer coil
beyond the distal end of the shaft body and into the proximal end
of the tip member.
[0079] In Example 25, the method of any one or any combination of
Examples 19-24 can optionally further comprise delivering a
radiopaque, diagnostic or therapeutic agent through the inner lumen
of the catheter.
[0080] In Example 26, the method of any one or any combination of
Examples 19-25 can optionally further comprise viewing a tip
member, disposed at the distal end of the catheter, using an
imaging means.
[0081] In Example 27, the method of any one or any combination of
Examples 19-26 can optionally further comprise exchanging the
guidewire advanced to the location proximate the stenosis or
narrowing with a second guidewire.
[0082] In Example 28, the catheter or method of any one or any
combination of Examples 1-27 can optionally be configured such that
all features, components, operations or other options are available
to use or select from.
[0083] Certain terms are used throughout this patent document to
refer to particular features or components. As one skilled in the
art appreciates, different people may refer to the same feature or
component by different names. This patent document does not intend
to distinguish between components or features that differ in name
but not in function.
[0084] For the following defined terms, certain definitions shall
be applied unless a different definition is given elsewhere in this
patent document. The terms "a," "an," and "the" are used to include
one or more than one, independent of any other instances or usages
of "at least one" or "one or more." The term "or" is used to refer
to a nonexclusive or, such that "A or B" includes "A but not B," "B
but not A," and "A and B." All numeric values are assumed to be
modified by the term "about," whether or not explicitly indicated.
The term "about" 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" can include numbers that are rounded to the nearest
significant figure. The recitation of numerical ranges by endpoints
includes all numbers and sub-ranges within and bounding that range
(e.g., 1 to 4 includes 1, 1.5, 1.75, 2, 2.3, 2.6, 2.9, etc. and 1
to 1.5, 1 to 2, 1 to 3, 2 to 3.5, 2 to 4, 3 to 4, etc.). The terms
"patient" and "subject" are intended to include mammals, such as
for human or veterinary applications. The terms "distal" and
"proximal" are used to refer to a position or direction relative to
the treating clinician. "Distal" and "distally" refer to a position
that is distant from, or in a direction away from, the treating
clinician. "Proximal" and "proximally" refer to a position that is
near, or in a direction toward, the treating clinician.
[0085] The scope of the invention should be determined with
reference to the appended claims, along with the full scope of
equivalents to which such claims are entitled. In the appended
claims, the terms "including" and "in which" are used as the
plain-English equivalents of the respective terms "comprising" and
"wherein." Also, in the following claims, the terms "including" and
"comprising" are open-ended; that is, a device, kit or method that
includes features or components in addition to those listed after
such a term in a claim are still deemed to fall within the scope of
that claim. Moreover, in the following claims, the terms "first,"
"second" and "third," etc. are used merely as labels, and are not
intended to impose numerical requirements on their objects.
[0086] The Abstract is provided to allow the reader to quickly
ascertain the nature of the technical disclosure. It is submitted
with the understanding that it will not be used to interpret or
limit the scope or meaning of the claims.
* * * * *