U.S. patent application number 09/223223 was filed with the patent office on 2001-07-26 for guidewire with multiple polymer jackets over distal and intermediate core sections.
This patent application is currently assigned to Edward J. Lynch. Invention is credited to BIAGTAN, EMANUEL, CORNISH, WAYNE E., RICHARDSON, MARK.
Application Number | 20010009980 09/223223 |
Document ID | / |
Family ID | 22835588 |
Filed Date | 2001-07-26 |
United States Patent
Application |
20010009980 |
Kind Code |
A1 |
RICHARDSON, MARK ; et
al. |
July 26, 2001 |
GUIDEWIRE WITH MULTIPLE POLYMER JACKETS OVER DISTAL AND
INTERMEDIATE CORE SECTIONS
Abstract
The invention is directed to a guide wire having at least two
different polymeric jackets that impart different handling
characteristics to the portions of the guide wire they surround.
Preferably, the guide wire may have jackets of different grades of
polymer, such as polyurethane 55D and 90A. Alternatively, the guide
wire may have jackets of different types of polymers such as
polyurethane and polytetrafluoroethylene, or may have a single
polymeric jacket with continuously varying properties along its
length. The invention also comprises methods of making such guide
wires.
Inventors: |
RICHARDSON, MARK;
(ESCONDIDO, CA) ; BIAGTAN, EMANUEL; (TEMECULA,
CA) ; CORNISH, WAYNE E.; (OCEANSIDE, CA) |
Correspondence
Address: |
EDWARD J LYNCH
HELLER EHRMAN WHITE AND MCAULIFFE
525 UNIVERSITY AVENUE
PALO ALTO
CA
943011900
|
Assignee: |
Edward J. Lynch
|
Family ID: |
22835588 |
Appl. No.: |
09/223223 |
Filed: |
December 30, 1998 |
Current U.S.
Class: |
600/585 |
Current CPC
Class: |
A61M 2025/09133
20130101; A61M 25/09 20130101; A61M 2025/09091 20130101 |
Class at
Publication: |
600/585 |
International
Class: |
A61B 005/00 |
Claims
What is claimed is:
1. A guide wire comprising an elongate core member having a
proximal portion, an intermediate portion and a distal portion, a
first polymeric jacket disposed about at least part of the
intermediate portion and a second polymeric jacket disposed about
at least part of the distal portion.
2. The guide wire of claim 1 wherein the first and second polymeric
jackets have different physical characteristics.
3. The guide wire of claim 2 wherein the first and second polymeric
jackets have different shore hardnesses.
4. The guide wire of claim 2 further comprising at least one
additional polymeric jacket disposed about the elongate core member
and having physical characteristics different from the first and
second polymeric jacket.
5. The guide wire of claim 3 wherein the first polymeric jacket
comprises polyurethane having a shore hardness of about 50 D to
about 60 D, and the second polymeric jacket comprises polyurethane
having a shore hardness of about 85 A to about 95 A.
6. The guide wire of claim 3 wherein the second polymeric jacket
comprises a fluoropolymer.
7. The guide wire of claim 6 wherein the first polymeric jacket
comprises a polyurethane and the second polymeric jacket comprises
a flouropolymer.
8. The guide wire of claim 1 wherein a distal portion of the guide
wire further comprises a shapeable coil secured to the elongate
core member and wherein the second polymeric jacket is disposed
about the shapeable coil.
9. The guide wire of claim 8 wherein shapeable coil has spaces
between adjacent coils and spaces between the shapeable coil and
the elongate core member and wherein the polymeric jacket fills
substantially all the spaces.
10. A guide wire having a first polymeric jacket disposed about a
first portion of the guide wire and a second polymeric jacket
disposed about a second portion of the guide wire such that the
jackets provide different handling properties to the first and
second portion of the guide wire.
11. The guide wire of claim 10 wherein the first polymeric jacket
has a greater shore hardness than the second polymeric jacket.
12. The guide wire of claim 11 further comprising a lubricious
coating on at least one of the polymeric jackets.
13. A process for manufacturing guide wires, comprising: a)
jacketing an intermediate portion of a guidewire with a first
polymeric tube; and b) jacketing a distal portion of the guidewire
with a second polymeric tube.
14. The process of claim 13 wherein the distal portion and the
intermediate portion of the guidewire are jacketed by hot die
necking.
15. The process of claim 13 wherein the distal portion of the
guidewire further comprises a shapeable coil disposed about an
elongate core member and the jacketing of the distal portion and
intermediate portion of the guidewire further comprises minimizing
air voids.
16. The process of claim 13 further comprising coating at least one
of the polymeric jackets with a lubricious coating.
17. A guide wire comprising an elongate core member having a
proximal portion, an intermediate portion and a distal portion, and
a polymeric jacket disposed about at least part of the intermediate
portion and the distal portion and having a shore hardness that
varies along the longitudinal length of the polymer jacket.
18. The guide wire of claim 17 wherein the polymer jacket further
comprises a proximal end and a distal end and varies in shore
hardness from about 55 D at a proximal end to about 90 A at a
distal end.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to the field of guide wires for
advancing intraluminal devices such as stent delivery catheters,
balloon dilatation catheters, atherectomy catheters and the like
within body lumens.
[0002] In a typical percutaneous procedure, a guiding catheter
having a preformed distal tip is percutaneously introduced into a
patient's peripheral artery, e.g. femoral or brachial artery, by
means of a conventional Seldinger technique and advanced therein
until the distal tip of the guiding catheter is seated in the
ostium of the desired coronary artery. There are two basic
techniques for advancing a guide wire into the desired location
within the patient's coronary anatomy, the first is a pre-load
technique which is used primarily for over-the-wire (OTW) devices
and the bare wire technique which is used primarily for rail type
systems.
[0003] With the pre-load technique, a guide wire is positioned
within an inner lumen of an OTW device such as a dilatation
catheter or stent delivery catheter with the distal tip of the
guide wire just proximal to the distal tip of the catheter and then
both are advanced through the guiding catheter to the distal end
thereof. The guide wire is first advanced out of the distal end of
the guiding catheter into the patient's coronary vasculature until
the distal end of the guide wire crosses the arterial location
where the interventional procedure is to be performed, e.g. a
lesion to be dilated or a dilated region where a stent is to be
deployed. The catheter, which is slidably mounted onto the guide
wire, is advanced out of the guiding catheter into the patient's
coronary anatomy by sliding over the previously introduced guide
wire until the operative portion of the intravascular device, e.g.
the balloon of a dilatation or a stent delivery catheter, is
properly positioned across the arterial location. Once the catheter
is in position with the operative means located within the desired
arterial location, the interventional procedure is performed.
[0004] With the bare wire technique, the guide wire is first
advanced by itself through the guiding catheter until the distal
tip of the guide wire extends beyond the arterial location where
the procedure is to be performed. Then a rail type catheter, such
as described in U.S. Pat. No. 5,061,395 (Yock) and the previously
discussed McInnes et al. which are incorporated herein by
reference, is mounted onto the proximal portion of the guide wire
which extends out of the proximal end of the guiding catheter which
is outside of the patient. The catheter is advanced over the guide
wire, while the position of the guide wire is fixed, until the
operative means on the rail type catheter is disposed within the
arterial location where the procedure is to be performed. After the
procedure the intravascular device may be withdrawn from the
patient over the guide wire or the guide wire repositioned within
the coronary anatomy for an additional procedure.
[0005] Further details of guide wires, and devices associated
therewith for various interventional procedures can be found in
U.S. Pat. Nos. 4,748,986 (Morrison et al.); 4,538,622 (Samson et
al.): 5,135,503 (Abrams); 5,341,818 (Abrams et al.); and 5,345,945
(Hodgson, et al.) which are hereby incorporated herein in their
entirety by reference thereto.
[0006] Conventional guide wires for angioplasty, stent delivery,
atherectomy and other vascular procedures usually comprise an
elongate core member with one or more tapered sections near the
distal end thereof and a flexible body member such as a helical
coil or a tubular body of polymeric material disposed about the
distal portion of the core member. A shapeable member, which may be
the distal extremity of the core member or a separate shapeable
ribbon which is secured to the distal extremity of the core member
extends through the flexible body and is secured to the distal end
of the flexible body by soldering, brazing or welding which forms a
rounded distal tip. Torquing means are provided on the proximal end
of the core member to rotate, and thereby steer, the guide wire
while it is being advanced through a patient's vascular system.
[0007] A problem confronting designers of successful guide wires is
the desirability to provide different physical characteristics for
different parts of the guide wire. For example, many guide wires
have a highly flexible leading tip designed not to damage or
perforate the vessel. Further, the portion behind the distal tip is
increasingly stiff to better support a balloon catheter or similar
device. The more proximal portion of the guide wire must also have
sufficient torsional rigidity to allow the tip to be steered
through the coronary vasculature.
[0008] One solution that has been employed is to provide a guide
wire having a core member with tapered diameters as discussed
above. However, it can be difficult to obtain the desired handling
characteristics on the basis of core wire dimensions alone. Other
solutions have involved the use of different materials for
different portions of the guide wire. These attempts raise new
problems in obtaining appropriately secure connections between the
different materials while maintaining the desired low profile.
Further, it can be important to provide a smooth transition between
regions of different stiffness in a guide wire to minimize the
potential of kinking.
[0009] It is also desirable to provide a guide wire with a
lubricious coating to facilitate advancement of the guide wire
through the tortuous coronary vasculature. However, placing
suitable coatings on metal guide wires raises significant
manufacturing problems. Typically, the metal surface must be
pretreated to allow adhesion of the lubricious coating. This adds
to the expense and difficulty of producing guide wires. The present
invention solves these and other problems.
SUMMARY OF THE INVENTION
[0010] This invention is directed to an elongate intraluminal
device having an elongate core member with a proximal portion, an
intermediate portion and a distal portion with a first polymeric
jacket and a second polymeric jacket disposed about the core
member. In a preferred embodiment, the first polymeric jacket is
disposed about the intermediate portion of the elongate core and
the second polymeric jacket is disposed about the distal portion of
the core. Preferably, the intraluminal device is a guidewire and
the first polymeric jacket is composed of a different polymer than
the second polymeric jacket, or the first polymeric jacket has
different polymeric properties than the second polymeric jacket.
The use of different polymers or polymer properties imparts
different handling characteristics to the various portions of the
guide wire. Preferably, the first polymeric jacket is harder or has
a higher shore hardness than the second polymeric jacket so that
the distal portion of the guide wire is more flexible than the
intermediate portion.
[0011] The polymeric jackets may comprise any suitable polymers
such as polyurethanes or fluoropolymers. In one preferred
embodiment, the first jacket comprises polyurethane having a shore
hardness of up to about 70 D, preferably about 50 D to about 60 D.
The second jacket is generally is of a softer or more flexible
material than the first jacket. Typically a polyurethane having a
shore hardness of about 75 A to about 100 A, preferably about 85 A
to about 95 A is used for the second jacket. In a typical
embodiment, a first jacket of shore hardness 55 D is used with a
second jacket having a durometer of 90 A. While the use of two
discrete polymer jackets is preferred, the invention is also
directed to the use of three or more polymer jackets as well as a
single polymer jacket having a continuously varying shore hardness
over a longitudinal length of the single polymer jacket. In another
preferred embodiment, the first jacket is made of polyurethane
while the second jacket is made of a fluoropolymer. In embodiments
where the guide wire has a shapeable coil at the distal tip, the
second jacket should cover the coil.
[0012] The invention also includes a processes for making guide
wires having multiple polymeric jackets or a jacket of continuously
varying characteristics to impart differing handling
characteristics to different portions of the guide wire.
Preferably, the process involves jacketing the guide wire by hot
die necking. In embodiments where the guide wire has a shapeable
coil over a core member, it may be desirable to configure the
process so that gaps between the turns of the coil and between the
coil and the core member are filled with polymeric material to
minimize any air voids.
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] FIG. 1 illustrates a guide wire of the invention having a
shapeable coil tip and first and second polymeric jackets.
[0014] FIGS. 2 and 3 are cross sections of the guide wire of FIG. 1
showing the first and second polymeric jackets.
[0015] FIG. 4 shows an alternate embodiment of the invention having
different configuration of polymeric jackets.
[0016] FIGS. 5 and 6 are cross sections of the guide wire of FIG. 4
showing the first and second polymeric jackets.
[0017] FIG. 7 is another embodiment of the invention with first and
second polymeric jackets and without a helical coil distal tip.
[0018] FIGS. 8-10 are cross sections of the guide wire of FIG. 7
showing the first, second and third polymeric jackets.
[0019] FIG. 11 is an elevational view in partial section of a
guidewire having features of the invention.
DETAILED DESCRIPTION OF THE INVENTION
[0020] As shown in FIGS. 1-3, a guide wire 10 of the present
invention generally comprises a proximal core portion 1 2, an
intermediate core portion 14 and a distal core portion 16. Running
through the proximal, intermediate and distal core portions of the
guide wire 10 is an elongated core member 18 typically having
varying diameters to provide different handling characteristics to
the different portions of the guide wire. A typical 0.014 inch
diameter guide wire to be used in coronary applications will
preferably have sections with diameters of about 0.014 in., 0.010
to 0.007 in., 0.005 to 0.004 in., and 0.003 to 0.002 in. extending
from the proximal end to the distal end. However, other diameters
are also suitable for the invention depending on the application.
For example, guide wires used in the peripheral vasculature would
be correspondingly larger. Generally, elongate core member 18 of
guide wire 10 is stainless steel, but it may also comprise a shape
memory material such as nickel-titanium alloys or other materials.
Guide wire 10 has a shapeable distal tip 20 that comprises a
flexible helical coil 22. The distal end has a rounded end 24,
preferably formed by a solder plug securing helical coil 22 to core
member 18.
[0021] As shown in the cross sections FIGS. 2 and 3, polymeric
jackets 26 and 28 surround intermediate core portion 14 and distal
core portion 16, respectively. In this embodiment, the polymeric
jackets comprise polyurethane, with jacket 26 having a shore
hardness of about 50 D to about 60 D and jacket 28 having a shore
hardness of about 85 A to about 95 A. By selecting different grades
of polymer, the intermediate 14 and distal 16 portions of guide
wire 10 can be given different handling characteristics. In some
embodiments, it may be preferable to configure the guide wire so
that any spaces between the individual coils of the helical coil 22
or between the coil 22 and the core member 18 are substantially
filled by polymeric jacket 28.
[0022] FIGS. 4-6 show an alternative embodiment, wherein guide wire
30 comprises proximal 32, intermediate 34 and distal 36 core
portions formed from elongated core member 38. Guide wire 30 also
has a shapeable distal tip 40, comprising helical coil 42 secured
to core member 38. Cross sections FIGS. 5 and 6 show polymeric
jackets 46 and 48 surrounding intermediate core portion 34 and
distal core portion 36, respectively. In this embodiment, polymeric
jacket 46 comprises polyurethane while jacket 28 comprises a
fluoropolymer such as polytetrafluoroethylene (PTFE). As before,
selecting different types of polymers for the two jackets imparts
different mechanical and handling characteristics to the different
regions of the guide wire.
[0023] FIGS. 7-10 show yet another embodiment of the invention,
wherein guide wire 50 similarly comprises proximal 52, intermediate
54 and distal 56 core portions formed from elongated core member
58. However, the shapeable distal tip comprises a shapeable ribbon
60 rather than a helical coil. FIGS. 8-10 show cross sections of
guide wire 50, wherein the intermediate core portion 54 has
polymeric jacket 62, distal core portion 56 has polymeric jacket 64
and a third polymeric jacket 66 bridges the intermediate core
portion 54 and the distal core portion 56. As before, the jackets
desirably have polymers of different type or grade so that the
intermediate and distal portions of the guide wire may be designed
to have different handling characteristics. The use of a third type
of polymer for the third jacket 66 provides greater control over
the handling characteristics of the guide wire.
[0024] Further, polymeric jackets 62, 64 and 66 have a lubricious
coating 68 to facilitate travel of the guide wire 50 through a
patient's vasculature. A lubricious coating is very easy to apply
to polymers and thus this avoids the difficulties attendant in
obtaining adequate adhesion of a lubricious coating to the metal of
the guide wire. In addition, while the materials for polymer
jackets 62, 64, and 66 can be chosen for mechanical properties, the
polymers of the jackets can also be selected for surface
characteristics. The lubricious, hydrophylic, and hydrophobic
characteristics of polymers used for polymer jackets 62, 64, and 66
can be selected to provide optimum performance of the guidewire
50.
[0025] While polymer jackets 62, 64 and 66 have been described as
discrete, it is also possible for the jackets to be blended
together at the boundaries therebetween, or for any single jacket
member to have a varying composition over its entire length that
varies the shore hardness of the jacket over the length. For
example, in FIG. 7, if jackets 62, 64 and 66 are combined into a
single jacket member, that jacket member can have a hardness of
about 50 D to about 60 D, preferably about 55 D at a proximal end
of the combined jacket and a hardness of about 85 A to about 95 A,
preferably about 90 A at a distal end of the combined jacket. The
hardness variation from the proximal end of the jacket to the
distal end of the jacket could vary in any useful continuous manner
including linearly or according to some other desired function. A
continuous variation in shore hardness of a polymer jacket can be
achieved by varying the mixture of two polymers having different
shore hardnesses during the extrusion process. Another method for
varying the shore hardness of a single polymer jacket is to
radiation treat the polymer jacket to a varying degree along its
longitudinal length. It is known in the art that certain types of
gamma or e-beam radiation can alter the shore hardness of certain
polymers depending on the intensity and duration of exposure.
[0026] The invention also comprises processes for manufacturing
guide wires having the features described above. Generally, the
process of the invention includes the steps of providing a guide
wire having proximal, intermediate and distal core portions;
jacketing the intermediate core portion with a first polymeric
material and jacketing the distal core portion with a second
polymeric material. The polymeric materials should be processed so
that they conform closely to the elongated core member and the
shapeable distal tip. Preferably, tubes or sleeves of polymeric
material are hot die necked onto the guide wire. As an alternative,
tubes or sleeves of suitable polymeric material can be heat shrunk
over an elongate core member to produce the desired result. In some
embodiments, it may be desirable to minimize any air gaps between
the helical coil itself or between the coil and the core member.
This may be achieved by heating the die to assure the polymer flows
into the coil. Additionally, a lubricious coating may be applied to
the surface of at least a portion of the polymeric jackets.
Homopolymers, copolymers, blends, and coextrusions may be used to
vary the properties of the polymers.
[0027] As discussed above the polymeric material may be any
suitable, biocompatible material including polymers such as
polyurethane, fluoropolymers such as polytetrafluoroethylene, PVC,
polyimide, polyamide, Nylon PET, PEEK and the like. In one
preferred embodiment, a guide wire is jacketed with a first
polymeric material comprising polyurethane and a second polymeric
material comprising polytetrafluoroethylene. Where the first and
second polymeric material are the same, different grades or shore
hardnesses should be used to impart different handling
characteristics to the different portions of the guide wire. For
example, in another preferred embodiment, a guide wire is jacketed
with a first polymeric material comprising polyurethane having a
hardness of about 55 D and a second polymeric material comprising
polyurethane having a hardness of about 90 A. In yet other
embodiments, it may be desirable to provide more than two different
polymeric jackets in order to impart a greater range of handling
characteristics to the guide wire. In addition to shore hardness,
other characteristics of the polymeric jackets can be varied to
produce the desired performance. For example, the radiopacity of
the polymeric jackets could be varied by including differing
percentages by weight of radiopaque materials in the polymer
material. Suitable radiopaque materials would include tantalum
powder, barium sulfate, bismuth, gold, platinum and the like.
[0028] FIG. 11 shows an alternative embodiment of a guidewire 70
having features of the invention. The guidewire 70 has an elongate
core member 71 with a proximal core section 72 and a distal core
section 73. The distal core section has a proximal end 74 and a
distal end 75 which is preferably rounded. The distal core section
73 has a tapered segment 76 located at the proximal end 74. A
helical coil 77 is disposed about a portion of the distal core
section 73. The helical coil 77 is preferably made from a
radiopaque metal such as gold, platinum, tantalum, iridium or the
like, but can also be made out of stainless steel or other suitable
alloys. A first polymer jacket 78 and second polymer jacket 81 are
disposed about the distal core section 73 and encompass the helical
coil 77 and any gaps between portions of the helical coil. The
first polymer jacket 78 and second polymer jacket 81 are joined at
lap joint 82. The lap joint 82 is angled with respect to a line
perpendicular to a longitudinal axis of the elongate core member
71. The angled lap joint 82 provides a strong smooth transition
between the first polymer jacket 78 and second polymer jacket 81.
The second polymer jacket 81 has a distal end 83 that is preferably
rounded to reduce trauma to the inside surface of a patient's body
passageways in which the guidewire 70 is advancing.
[0029] The distal core section 73 of the elongate core member 71
has a substantially constant outer diameter over a length thereof.
The outer diameter of the distal section is about 0.002 to about
0.01 inches, preferably about 0.005 to about 0.007 inches. The
length of the distal core section 73 is about 10 to about 60 cm,
preferably about 20 to about 40 cm. The proximal core section 72
has an outer diameter of about 0.011 to about 0.015 inches,
preferably about 0.012 to about 0.014 inches. The elongate core
member 71 is made of stainless steel, but could also be made of
pseudoelastic alloys such as NiTi, or high strength precipitation
hardenable alloys such as MP35N, L605, precipitation hardenable
stainless steel or the like. The first polymer jacket 78 is made
from a polyurethane with a shore hardness of about 55 D to about 65
D. The second polymer jacket 81 is made from a polyurethane with a
shore hardness of about 75 A to about 85 A. As with the previously
described embodiments of the invention, the first and second
polymer jackets 78 and 81 can be made from a variety of polymer
materials including polyamides, copolymers, and nylons such as
Pebax. Although guidewire 70 is shown in FIG. 11 with two polymer
jackets, three or more polymer jackets could be used to cover or
partially cover the distal core section 73 of the elongate core
member. Also, in addition to multiple polymer jackets that are
softer and more flexible distally along the elongate core member
71, alternative configurations could be used whereby an
intermediate polymer jacket has a shore hardness less than a
proximal polymer jacket located proximally to the intermediate
polymer jacket and less than a distal polymer jacket located distal
to the intermediate polymer jacket. This would give the guidewire a
distal section with a more flexible intermediate portion.
[0030] While particular forms of the invention have been
illustrated and described, it will be apparent that various
modifications can be made without departing from the spirit and
scope of the invention. Accordingly, it is not intended that the
invention be limited, except as by the appended claims.
* * * * *