U.S. patent application number 10/358779 was filed with the patent office on 2003-09-04 for catheter assemblies with flexible radiopaque marker.
Invention is credited to Gutting, Christine, Heinemann, Gary, Lee, Jeong S., Navak, Vidya, Schreiner, John, Wang, Edwin, White, Roseminda.
Application Number | 20030167052 10/358779 |
Document ID | / |
Family ID | 23884502 |
Filed Date | 2003-09-04 |
United States Patent
Application |
20030167052 |
Kind Code |
A1 |
Lee, Jeong S. ; et
al. |
September 4, 2003 |
Catheter assemblies with flexible radiopaque marker
Abstract
A catheter assembly comprising a shaft and at least one flexible
radiopaque marker affixed with the shaft. Flexibility of radiopaque
marker is achieved by using a segmented band of radiopaque material
or a coiled band formed by winding a wire or hollow tube filled
with radiopaque material. The flexible radiopaque marker may be
affixed with the shaft by an adhesive, by swaging, by crimping, by
soldering, or by spring-action tension fit against the shaft.
Inventors: |
Lee, Jeong S.; (Diamond Bar,
CA) ; Navak, Vidya; (Cupertino, CA) ;
Schreiner, John; (Hemet, CA) ; Gutting,
Christine; (Murrieta, CA) ; Wang, Edwin;
(Tustin, CA) ; Heinemann, Gary; (Campbell, CA)
; White, Roseminda; (Wildomar, CA) |
Correspondence
Address: |
James C. Scheller, Jr.
BLAKELY, SOKOLOFF, TAYLOR & ZAFMAN LLP
Seventh Floor
12400 Wilshire Boulevard
Los Angeles
CA
90025-1026
US
|
Family ID: |
23884502 |
Appl. No.: |
10/358779 |
Filed: |
February 4, 2003 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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10358779 |
Feb 4, 2003 |
|
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|
09474668 |
Dec 29, 1999 |
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6520934 |
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Current U.S.
Class: |
604/529 ;
600/424; 604/103.1 |
Current CPC
Class: |
A61M 2025/1079 20130101;
A61M 25/0108 20130101 |
Class at
Publication: |
604/529 ;
600/424; 604/103.1 |
International
Class: |
A61M 025/098 |
Claims
What is claimed is:
1. A catheter assembly comprising: at least one flexible radiopaque
marker for visualizing a portion of the catheter assembly under a
fluoroscope.
2. The catheter assembly as described in claim 1, wherein the
flexible radiopaque marker comprises a radiopaque metal.
3. The catheter assembly as described in claim 1, wherein the
flexible radiopaque marker comprises a radiopaque material selected
from the group consisting of: gold, platinum, iridium, tungsten,
nickel, tantalum, iron, carbon, manganese, cobalt and alloys
thereof.
4. The catheter assembly as described in claim 1, wherein the
flexible radiopaque marker comprises a polymeric material and a
radiopaque agent.
5. The catheter assembly as described in claim 4, wherein the
radiopaque agent is selected from the group consisting of: barium,
bismuth, tungsten, and compounds thereof.
6. The catheter assembly as described in claim 4, wherein the
polymeric material is selected from the group consisting of:
polyurethane, polyamide, polyester, polyether, polyimide,
polyethylene, polypropylene, and co-polymers thereof.
7. The catheter assembly as described in claim 4, wherein the
polymeric material has up to approximately 25% by volume of the
radiopaque agent incorporated therein.
8. The catheter assembly as described in claim 1, wherein the
flexible radiopaque marker comprises a polyether-polyamide block
co-polymer with approximately 25% by volume of bismuth trioxide
incorporated therein.
9. The catheter assembly as described in claim 1, further
comprising a shaft, wherein the flexible radiopaque marker is
affixed with the shaft.
10. The catheter assembly as described in claim 9, wherein the
flexible radiopaque marker is wrapped around the shaft.
11. The catheter assembly as described in claim 9, wherein the
flexible radiopaque marker is crimped to the shaft.
12. The catheter assembly as described in claim 9, wherein the
flexible radiopaque marker is swaged to the shaft.
13. The catheter assembly as described in claim 9, wherein the
flexible radiopaque marker is affixed with an adhesive.
14. The catheter assembly as described in claim 13, wherein the
adhesive is a flexible adhesive.
15. The catheter assembly as described in claim 13, wherein the
adhesive is selected from the group consisting of: silicone-based,
urethane-based and cyanoacrylate-based adhesives.
16. The catheter assembly as described in claim 9, wherein the
shaft has an inner surface and an outer surface, the flexible
radiopaque marker being affixed on the inner surface.
17. The catheter assembly as described in claim 9, wherein the
shaft has an inner surface and an outer surface, the flexible
radiopaque marker being affixed on the inner surface.
18. The catheter assembly as described in claim 1, further
comprising a balloon member having a proximal portion, a distal
portion, and an inflatable portion therebetween.
19. The catheter assembly as described in claim 18, wherein one
flexible radiopaque marker defines a midpoint of the inflatable
portion.
20. The catheter assembly as described in claim 18, wherein the
flexible radiopaque marker has a length corresponding to a working
length of the balloon member.
21. The catheter assembly as described in claim 18, wherein the
catheter assembly has two flexible radiopaque markers and the
inflatable portion has a proximal end and a distal end, wherein one
flexible radiopaque marker is positioned to indicate the proximal
end and the other flexible radiopaque marker is positioned to
indicate the distal end.
22. The catheter assembly as described in claim 1, wherein the
flexible radiopaque marker has a length of between about 1
millimeter to about 50 millimeters.
23. The catheter assembly as described in claim 1, wherein the
flexible radiopaque marker has a length of between about 1
millimeter to about 3 millimeters.
24. A catheter assembly having at least one segmented marker band
comprising a radiopaque material.
25. The catheter assembly as described in claim 24, wherein the
segmented band has two ends and comprises a longitudinal slit
formed from one end of the segmented band to the other end of the
segmented band.
26. The catheter assembly as described in claim 24, wherein the
segmented band comprises a solid band having a longitudinal axis
and at least one notch formed transverse the longitudinal axis.
27. A catheter assembly having at least one marker coil comprising
a radiopaque material.
28. The catheter assembly as described in claim 27, wherein the
coil is formed from a wire of the radiopaque material.
29. The catheter assembly as described in claim 27, wherein the
coil is formed from a hollow tube filled with the radiopaque
material.
30. The catheter assembly as described in claim 29, wherein the
hollow tube comprises a material selected from the group consisting
of: stainless steel, gold, copper, and silver.
31. The catheter assembly as described in claim 27, wherein the
marker coil is coated in a polymer layer.
32. The catheter assembly as described in claim 31, wherein the
polymer layer comprises a low durometer polymer.
33. The catheter assembly as described in claim 31, wherein the
polymer layer comprises a polymer selected from the group
consisting of: a polyurethane and a polyamide-polyether block
co-polymer.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to medical devices in general
and catheter assemblies having flexible radiopaque markers in
particular.
BACKGROUND
[0002] Catheters have found widespread clinical use, for both
diagnostic and interventional procedures. In performing, for
example, intravascular catheter procedures, a physician typically
uses a fluoroscope (e.g., an X-ray machine) to visualize a
patient's vascular structure. To assist the physician in guiding
and positioning the catheter within the patient's vascular system,
catheters typically have one or more marker bands affixed to the
shaft that are highly visible under the fluoroscope.
[0003] FIGS. 1A and 1B illustrate an example of a balloon catheter
assembly and a marker band, respectively, from the prior art. The
catheter assembly 10 comprises a shaft 15 and a balloon member 14
disposed around a distal section of the shaft 15. The balloon
member 14 has a proximal portion 11 and a distal portion 13 and an
inflatable portion 12 therebetween. The proximal portion 11 and the
distal portion 13 of the balloon member are affixed with a shaft
15. The catheter assembly 10 depicted in FIG. 1a has a single
marker band 19 positioned to indicate a midpoint of the inflatable
portion 12 of the balloon member 14.
[0004] The marker band 19 is shown in an expanded view in Figure
1B. The marker and 19 is a solid band of a radiopaque metal, such
as gold, platinum, tungsten, iridium, etc. and alloys thereof.
Typically, the marker band 19 is slipped around and onto the shaft
15 and then affixed to the shaft with an adhesive or by heating the
shaft.
[0005] Vascular structures can be very tortuous, and marker bands
of the prior art present an impediment to navigating the catheter
through such tortuous anatomy, especially around a tight bend,
because such marker bands are rigid and have no flexibility. The
marker band's rigidity additionally present problems to passing the
catheter through a lesion.
SUMMARY
[0006] The present invention provides catheter assemblies having at
least one flexible radiopaque marker affixed with the shaft. In one
embodiment of the present invention, the flexible radiopaque marker
is a segmented band of a radiopaque material. Advantageously, the
segmented band further has a longitudinal slit running from one end
of the segmented band to the opposite end of the segmented band. In
another embodiment, the flexible radiopaque marker comprises a coil
of a radiopaque material. The radiopaque material may comprise a
radiopaque metal. Alternatively, the radiopaque material may
comprise a polymeric material loaded with a radiopaque agent.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1A is a cross-sectional view of a catheter assembly of
the prior art having a single marker band.
[0008] FIG. 1B shows an expanded view of a marker band of the prior
art.
[0009] FIG. 2 is a cross-sectional view of one embodiment of a
catheter assembly having a flexible radiopaque marker in accordance
with the present invention.
[0010] FIGS. 3A and 3B show expanded views of two embodiments of
the flexible radiopaque marker in accordance with the present
invention comprising a segmented band having two and three
segments, respectively.
[0011] FIGS. 4A and 4B show expanded views from the side and front
of a flexible radiopaque marker having a longitudinal slit in
accordance with the present invention.
[0012] FIG. 5 shows an embodiment of the flexible radiopaque marker
in accordance with the present invention comprising a coil having
four segments.
[0013] FIG. 6 shows one embodiment of a catheter assembly having
two flexible radiopaque markers in accordance with the present
invention.
DETAILED DESCRIPTION
[0014] The present invention will be described below in connection
with the embodiments depicted in the figures. Neither the figures
nor the descriptions below are intended to limit the present
invention in any way. In particular, although the present invention
will be described in the context of catheters and balloon catheter
assemblies, the present invention may be used in conjunction with
other types of medical devices, such as stents, sheaths, inflation
devices, and the like, that are inserted into a body where
visibility under a fluoroscope is desired.
[0015] In the following description, specific details are set forth
to provide a thorough understanding of the present invention,
however, it will be appreciated by those of ordinary skill in the
art that the present invention may be practiced without these
specific details. In other instances, details of well-known steps,
structures and techniques have been omitted to avoid obscuring the
present invention.
[0016] FIG. 2 depicts one embodiment of a catheter assembly that
incorporates a flexible radiopaque marker of the present invention.
The catheter assembly 20 depicted in FIG. 2 is similar to the
catheter assembly 10 shown in FIG. 1. The catheter assembly 20 has
a single flexible radiopaque marker 26 affixed on an outer surface
of a shaft 24 and positioned so as to indicate the midpoint of an
inflatable portion 22 of a balloon member 25.
[0017] FIG. 3A shows an expanded view of the flexible radiopaque
marker 26 from the catheter assembly 20 of FIG. 2. In this
embodiment, the flexible radiopaque marker 26 comprises a band of a
radiopaque material having one notch 31 formed transverse the
longitudinal axis (A) of the band and that divides the band into
two segments 30a, 30b. The two segments 30a, 30b can move relative
to one another, allowing the flexible radiopaque marker 26 to bend
more easily than the solid bands of the prior art.
[0018] FIG. 3B depicts another embodiment of a flexible radiopaque
marker of the present invention. In this embodiment, the flexible
radiopaque marker 32 comprises a band of radiopaque material having
two notches 33a, 33b formed transverse the longitudinal axis (A)
thereof and that divide the band into three segments 34a, 34b, 34c.
As compared to the flexible radiopaque marker 26 shown in FIG. 3A,
the flexible radiopaque marker 32 shown in FIG. 3B has an
additional degree of freedom due to the additional segment and so
has even greater flexibility.
[0019] FIGS. 4A and 4B show two views of a variation on the type of
flexible radiopaque marker illustrated by the embodiments shown in
FIGS. 3A and 3B. The flexible radiopaque marker 40 shown in FIGS.
4A and 4B is similar to that shown in FIG. 3B, having two notches
41a, 41b and three segments 42a, 42b, 42c. Additionally, the
flexible radiopaque marker 40 has a longitudinal slit 43 running
from one end of the flexible radiopaque marker to the other end of
the flexible radiopaque marker. The longitudinal slit 43 allows the
flexible radiopaque marker to be wrapped around and embedded in the
catheter shaft, which allows the flexible radiopaque marker of the
present invention to have a smaller diameter and hence smaller
profile than the markers of the prior art that are slipped over the
inner shaft.
[0020] The notches and slits may be formed using a variety of
techniques known in the art, such as laser cutting and the like.
One of skill in the art will recognize that the type of flexible
radiopaque marker illustrated by the embodiments shown in FIGS.
3A-3B and 4A-4B may have as many notches and thus have as many
segments as can be formed therein. The more segments, the more
degrees of freedom and the greater the flexibility of the flexible
radiopaque marker.
[0021] FIG. 5 shows another embodiment of flexible radiopaque
marker according to the present invention. In this embodiment, the
flexible radiopaque marker 50 comprises a coil of radiopaque
material. Each turn of the coil 52a, 52b, 52c, 52d acts as a
separate segment. In one embodiment, the coiled flexible radiopaque
marker is made of a wire of radiopaque material. In another
embodiment, the coiled flexible radiopaque marker is made of a
hollow tube made of, e.g., stainless steel, gold, copper, silver,
and the like, and filled with a radiopaque material. The wire or
radiopaque filled tube may have an outer diameter of less than
about 3 mils, typically about 2 mils.
[0022] The coiled flexible radiopaque marker may be made by winding
or braiding the wire or radiopaque filled tube around a mandrel and
then assembled with the catheter assembly, or by winding or
braiding the wire or radiopaque-filled tube directly onto the
catheter shaft. The radiopaque coil marker may be wound directly
onto the catheter shaft under tension to form a flexible radiopaque
marker that is embedded into the catheter shaft. The wire or
radiopaque-filled tube may be wound continuously in one direction
to form a continuous coil (as shown in FIG. 5), or may be wound
back and forth in zigzag pattern around the mandrel or the
shaft.
[0023] In still another embodiment, the coiled flexible radiopaque
marker described above may be coated with a polymer layer, to keep
the ends of the wire from fraying and the coil from unraveling. The
polymer may be applied as a solution over the coil, or as a
heat-shrink film that is wrapped around the coil. Typically, the
polymer layer will be made of a soft polymer material, such as a
low durometer polyurethane, polyamide-polyether block co-polymer
(e.g., Pebax.RTM.), and the like.
[0024] The dimensions of the flexible radiopaque markers will
depend upon the particular application and particular device to
which the markers are affixed. For use with percutaneous
transluminal coronary angioplasty (PTCA) devices, for example,
flexible radiopaque markers that are affixed to the outer surface
of the catheter shaft will have an outer diameter typically in the
range of between about 22 mils and about 27 mils. For use with
peripheral percutaneous transluminal angioplasty devices, the
flexible radiopaque markers may have an outer diameter of up to
about 50 mils.
[0025] Typically, radiopaque markers have an overall length between
about 1 millimeter and about 3 millimeters. However, given the
increased flexibility of flexible radiopaque markers according to
the present invention, the flexible radiopaque marker may have a
much larger overall length. The overall length of a flexible
radiopaque marker according to the present invention may range
between about 1 millimeter and about 50 millimeters.
[0026] Flexible radiopaque markers of the present invention may be
affixed with the shaft by crimping, or by swaging, or with an
adhesive, or by heating, or by soldering, or by the spring-action
tension applied by the flexible radiopaque marker against the
shaft, or by other means known in the art. When an adhesive is
used, the adhesive is advantageously a flexible adhesive such as a
silicone-based adhesive, urethane-based adhesive,
cyanoacrylate-based adhesive, and the like.
[0027] Crimping, swaging and spring-action tension have the
advantage of reducing the outer diameter of the markers, or
allowing lower profile markers to be used, which would help
facilitate the navigation of the catheter assembly through tortuous
body lumen. It is noted that a longitudinal slit as shown in FIGS.
4A and 4B would facilitate (though is not necessary for) crimping,
swaging or spring-action tension of the flexible radiopaque markers
of the present invention.
[0028] The flexible radiopaque markers of the present invention are
made of a radiopaque material. The radiopaque material may be a
radiopaque metal, such as gold, platinum, iridium, tungsten,
nickel, tantalum, iron, carbon, manganese, cobalt, alloys thereof,
and the like. Alternatively, the radiopaque material may be a
polymeric material with a radiopaque agent incorporated therein.
The polymeric material advantageously provides further flexibility
for the flexible radiopaque markers of the present invention.
[0029] Any polymeric material may be used. Some examples of
polymeric materials that may be used in the present invention
include polyurethanes, polyamides, polyimides, polyesters,
polyethers, polyethylenes, polypropylenes, co-polymers thereof, and
the like. The polymeric materials may be expanded under pressure
and/or heat to facilitate assembly of the flexible radiopaque
marker onto the catheter shaft. Any radiopaque agent may be used.
Some examples of radiopaque agents that may be used in the present
invention include barium, bismuth, tungsten, compounds thereof, and
the like. In one embodiment, up to approximately 25% by volume of a
radiopaque agent is incorporated into the polymeric material
without detrimental effect in its mechanical properties. An example
of a radiopaque material suitable for use in the present invention
is a polyamide-polyether block co-polymer (e.g., Pebax.RTM.) having
approximately 25% by volume of bismuth trioxide incorporated
therein.
EXAMPLES
[0030] Two prototypical PTCA balloon catheter assemblies having
flexible radiopaque markers formed in accordance with the present
invention have been made. The PTCA balloon catheter assemblies had
a 3.times.18 millimeter balloon on a tri-layer
(Pebax.RTM./Primacor.RTM. (ethylene acrylate acid)/high density
polyethylene) shaft having an outer diameter of 20.5 mils.
[0031] Coiled flexible radiopaque markers were made from thin wires
of a platinum-iridium (Pt/Ir) alloy and of a platinum-nickel
(Pt/Ni) alloy having an outer diameter of 2 mils. The coiled
flexible radiopaque markers were formed by winding the wire around
a mandrel and then cut to have an overall length corresponding to
the working length of the balloon member, i.e., 18 millimeters. The
coiled radiopaque markers for these examples had an inner diameter
of slightly larger than the outer diameter of the shaft, i.e., 21
mils. It is noted, however, that, given the spring action of the
coil, coiled flexible radiopaque markers having an inner diameter
approximately the same or slightly smaller than the outer diameter
of the shaft may be used and assembled with catheter assemblies in
a manner similar as described below.
[0032] In these examples, the catheter assemblies were assembled
with the coiled radiopaque markers by first applying a thin layer
of adhesive to the outer surface of the tri-layer shaft. Then the
flexible radiopaque marker was slipped over the shaft and the layer
of adhesive, and affixed via the adhesive with the outer surface of
the shaft. The Pt/Ir flexible radiopaque marker was affixed using
an ultraviolet cured adhesive and had an outer diameter of 27 mils
(when assembled on the shaft). The Pt/Ni flexible radiopaque marker
was affixed using a cyanoacrylate-based adhesive and had an outer
diameter of 26 mils. The balloon member was then assembled over the
shaft and centered over the flexible radiopaque markers.
[0033] The PTCA catheter assemblies with Pt/Ir and Pt/Ni flexible
radiopaque markers as described above were observed to possess
greater visibility and greater flexibility than similar catheter
assemblies having solid marker bands of the same radiopaque
materials.
[0034] Although the catheter assemblies described above
incorporated only one flexible radiopaque marker, catheter
assemblies of the present invention are not so limited. Catheter
assemblies of the present invention can have more than one flexible
radiopaque markers affixed with the shaft, in which case it would
be advantageous to position the flexible radiopaque markers to
indicate specific positions of interest on the catheter. For
example, as shown in the embodiment with two flexible radiopaque
markers depicted in FIG. 6, it is advantageous to position a first
flexible radiopaque marker 76a to define a proximal end 73 of the
inflatable portion 72 of the balloon member and a second flexible
radiopaque marker 76b to define a distal end 75 of the inflatable
portion 72.
[0035] Flexible radiopaque markers of the present invention may be
affixed with (e.g., adhered with, embedded within or onto, crimped
or swaged around, etc.) either an inner surface or an outer surface
of the shaft, and may be used with any type of catheter assembly or
any type of medical device where visibility under a fluoroscope is
desired.
[0036] Those of ordinary skill in the art will understand that
numerous other variations, modifications and improvements may be
made to the embodiments and examples described above that still
fall within the scope of the invention as claimed.
* * * * *