U.S. patent number 4,636,346 [Application Number 06/698,561] was granted by the patent office on 1987-01-13 for preparing guiding catheter.
This patent grant is currently assigned to Cordis Corporation. Invention is credited to Jeffrey G. Gold, Gyan S. Pande, Kevin Smith.
United States Patent |
4,636,346 |
Gold , et al. |
January 13, 1987 |
Preparing guiding catheter
Abstract
A thin-walled guiding catheter of the type having a distal end
adapted to be formed into curved configurations and passed through
branching blood vessels and the like is prepared with a
three-layered tubular body portion having a lubricious inner sheath
defining a lubricious guiding lumen, a rigid intermediate sheath,
and a flexible outer sheath, which may be radiopaque. The distal
tip portion thereof has a similar construction, but from which the
rigid intermediate sheath is omitted. The guiding catheter exhibits
excellent torque response and control while being especially
thin-walled, thereby permitting minimization of the outer diameter
size while permitting passage of an intravascular catheter and the
like through its lumen.
Inventors: |
Gold; Jeffrey G. (Miami,
FL), Pande; Gyan S. (Miramar, FL), Smith; Kevin
(Miami, FL) |
Assignee: |
Cordis Corporation (Miami,
FL)
|
Family
ID: |
27080012 |
Appl.
No.: |
06/698,561 |
Filed: |
February 6, 1985 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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587382 |
Mar 8, 1984 |
4596563 |
Jun 24, 1986 |
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587557 |
Mar 8, 1984 |
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502526 |
Jun 9, 1983 |
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Current U.S.
Class: |
264/139; 138/109;
138/137; 138/177; 156/248; 264/149; 264/150; 264/159; 264/162;
264/171.26; 264/171.27; 264/171.28; 264/230; 264/248; 264/28;
264/344; 264/442; 604/523 |
Current CPC
Class: |
A61M
25/001 (20130101); A61M 25/00 (20130101) |
Current International
Class: |
A61M
25/00 (20060101); B29C 047/06 (); B29C
063/22 () |
Field of
Search: |
;264/173,174,150,139,167,149,230,344,23,28,159,248,162
;425/132,133.1 ;156/248 ;604/280 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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58-11118 |
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Jan 1983 |
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JP |
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1349843 |
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Apr 1974 |
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GB |
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1370281 |
|
Oct 1974 |
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GB |
|
Primary Examiner: Thurlow; Jeffery
Attorney, Agent or Firm: Lockwood, Alex, Fitzgibbon &
Cummings
Parent Case Text
This is a continuation-in-part of application Ser. No. 587,382,
filed Mar. 8, 1984, now U.S. Pat. No. 4,596,563 issued Jun. 24,
1986 and of application Ser. No. 587,557, filed Mar. 8, 1984, each
of which is a continuation-in-part of application Ser. No. 502,526,
filed June 9, 1983, now abandoned.
Claims
We claim:
1. A method of making a guiding catheter having a distal end
adapted to be formed into curved configurations and passed through
branching blood vessels and having a longitudinal lumen
therethrough for receiving an intravascular catheter and the like,
the method comprising:
forming a continuous and uninterrupted longitudinal lubricious
interior sheath coating onto a mandrel;
extruding a generally rigid intermediate sheath radially over the
lubricious interior sheath;
coating a generally flexible outer sheath radially over the
generally rigid intermediate sheath;
removing a distal end axial length of said generally flexible outer
sheath;
removing a distal end axial length of said generally rigid
intermediate sheath and thereby exposing a distal end axial length
of said lubricious interior sheath; and
securing a length of generally flexible outer sheath onto and over
said exposed distal end axial length of the continuous and
uninterrupted longitudinal lubricious interior sheath to thereby
form a two-layered atraumatic distal end tip portion that is an
axial length of generally flexible outer sheath secured onto the
exposed distal end axial length of the continuous lubricious
interior sheath.
2. The method according to claim 1, wherein said step of removing
the distal end length of the generally flexible outer sheath
includes using an abrasive member.
3. The method according to claim 1, wherein said step of removing
the distal end length of the generally rigid intermediate sheath
includes using a solvent.
4. A fuseless method of making a guiding catheter having a distal
end adapted to be formed into curved configurations and passed
through branching blood vessels and having a longitudinal lumen
therethrough for receiving an intravascular catheter and the like,
the method comprising:
coating a continuous and uninterrupted longitudinal lubricious
interior sheath coating onto a mandrel;
extruding a longitudinal axially gapped generally rigid
intermediate sheath radially over the lubricious interior sheath
coating, wherein said extruding step includes providing a
longitudinal axial gap and a longitudinal axial length of the
generally rigid intermediate sheath, said longitudinal axial gap
exposing an axial length of the lubricious interior sheath coating;
and
extruding a generally flexible outer sheath coating radially over
the longitudinal axially gapped generally rigid intermediate sheath
and the continuous and uninterrupted interior sheath, said
extruding step laying down a continuous and uninterrupted flexible
polymer elongated sheath over said longitudinal axial gap to form a
two-layered atraumatic distal end tip that is an axial length of
generally flexible outer sheath radially positioned over the
exposed length of the lubricious interior sheath coating, and the
continuous and uninterrupted flexible polymer elongated sheath laid
down by said extruding step is continuously laid down over said
longitudinal axial length of the generally rigid intermediate
sheath to form a tubular body integral with said atraumatic distal
end tip without fusing said atraumatic distal end tip to said
tubular body.
5. The fuseless method according to claim 4, wherein said step of
forming the longitudinally gapped generally rigid intermediate
sheath is carried out by intermittently extruding the generally
rigid intermediate sheath.
6. The fuseless method according to claim 4, wherein said step of
forming the longitudinally gapped generally rigid intermediate
sheath includes continuously extruding the generally rigid
intermediate sheath and removing a longitudinal gap length of the
generally rigid intermediate sheath.
7. The fuseless method according to claim 4, wherein said
lubricious interior sheath coating, said generally rigid
intermediate sheath and said generally flexible outer sheath are
coextruded.
Description
BACKGROUND AND DESCRIPTION OF THE INVENTION
The present invention generally relates to a guiding catheter and
method for making the same, and more particularly to a guiding
catheter that has a lubricious lumen and that is thin-walled while
still exhibiting excellent strength characteristics, the
thin-walled construction being one in which the elongated body of
the catheter includes a thin flexible outer sheath that overlies a
thin rigid intermediate sheath which in turn overlies a third,
interior sheath that provides the lubricious lumen. The guiding
catheter further includes a flexible, atraumatic tip portion
located at one end of the elongated tubular member, which tip
portion has a structure similar to the elongated body portion but
which does not include the rigid intermediate layer.
Guiding catheters are well-known for use in diagnostic and
therapeutic applications wherein they are used to provide a guiding
lumen through which a treating catheter such as an intravascular
catheter or the like is passed such that the treating catheter may
be used to administer a fluid to, or otherwise contact such as with
a balloon, a precise location within the cardiovascular system. In
order to accomplish this, the guiding catheter must be able to
traverse a pathway through, for example, branching blood vessels.
Prior to insertion of the treating catheter through the guiding
lumen of the guiding catheter, the guiding catheter is positioned
in the vicinity of the administration or treatment location, this
positioning being accomplished in part by manipulation of a
proximal portion of the guiding catheter in order to impart forces
needed to curve and guide the guiding catheter through the curving
and branching blood vessels, at times in association with a very
small diameter elongated flexible guide wire.
Typical assemblies including a guiding catheter and a treating
catheter are assemblies used for percutaneous transluminal coronary
angioplasty. In such systems or assemblies, it is important that
the guiding catheter, as well as the treating catheter, exhibit
adequate torque control while at the same time having a
substantially atraumatic tip. One such guiding catheter structure
is made by extruding a thin base coat of a polyfluoroethylene, such
as Teflon materials available from E.I. duPont de Nemours &
Co., Inc., over a mandrel, after which a braided material, which
may be metal wire, is positioned thereover, and coated with a
flexible material. Braided guiding catheters of this type do not
always provide the exceptional degree of torque control that is
desired for guiding catheters of the intravascular type, and they
may also exhibit a somewhat excessively stiff tip portion. Good
torque control is exhibited when slow rotation of the hub end of a
catheter is translated to the tip or distal end without "whipping",
which is characterized by a temporary lag in movement followed by a
rapid rotation.
Other guiding catheters that are especially useful in assemblies
for percutaneous transluminal recanalization of chronic
arterioschlerotic obstructions by catheterization techniques are of
structure that includes an inner hose having a surface layer of
synthetic fiber fabric such as a Nylon (duPont trademark)
polyamide, which is covered by a protective hose of a material such
as a fluoroethylenepropylene that is heat shrunk therearound.
Another guiding catheter provides a tetrafluoroethylene polymer
tubular member that is encased within a heat shrunk flexible
tubular member made of a modified polyolefin.
Because these guiding catheters are used in an intravascular
manner, they must have an extremely small outside diameter, while
still providing an inside diameter or lumen size that is adequate
to permit the passage of the treating catheter therethrough.
Furthermore, since these catheters come into contact with living
tissue, including organs such as the heart, it is extremely
important that the guiding catheter be in place for a minimal
length of time. Overall insertion time includes the length of time
needed to feed the guiding catheter through a cardiovascular system
and then feed the treating catheter through the lubricious lumen of
the guiding catheter. Such insertion time can be better controlled
if the guiding catheter is stiff enough to be resistant to the
formation of kinks therein, while at the same time possessing
enough flexibility to be responsive to maneuvering forces and to
provide adequate torque control when the guiding catheter is
manipulated in conjunction with feeding same through a somewhat
tortuous path. At the same time, the guiding catheter, particularly
its distal end or tip portion, should be as atraumatic as
possible.
The present invention provides a guiding catheter that meets these
needs and objectives by virtue of its having a multi-layered
structure which includes an innermost layer of a highly lubricious
material, onto which is coated a thin, rigid intermediate layer
which exhibits strength and stiffness properties that are extremely
advantageous for an intravascular guiding catheter while still
having adequate flexibility in its thin-walled sheath condition to
permit the flexibility required of such a catheter. Closely
overlying, and typically extruded onto, the rigid intermediate
sheath is a flexible, thin-walled outer sheath that is compatible
with the intermediate sheath and that, as a layer over the rigid
intermediate sheath, imparts improved atraumatic properties to the
longitudinal extent of the catheter and contributes to the overall
flexibility of the guiding catheter, while also providing
convenient opportunities to impart radiopaque properties to the
catheter. While these guiding catheters may be produced such that a
separate tip member is secured to the distal end of the body of the
guiding catheter, it is preferred that the guiding catheter be
structured in a manner such that the interior, lubricious sheath is
an integral, one-piece continuous sheath that extends through both
the body portion and the tip portion.
It is accordingly a general object of the present invention to
provide an improved guiding catheter that is particularly
well-suited for intravascular uses.
Another object of the present invention is to provide a
thin-walled, multi-layered catheter that is especially suitable for
use as a guiding catheter in conjunction with highly delicate
treatments and diagnostic procedures including coronary
angiography, coronary angioplasty, ventricular and/or aortic flush
injections, and other similar procedures within the cardiovascular
system.
Another object of this invention is to provide an improved
thin-walled guiding catheter and method of making same which
include positioning a highly lubricious lumen within a guiding
catheter exhibiting excellent torque control. Another object of the
present invention is to provide an improved guiding catheter and
method by which the body portion and the tip portion thereof share
a continuous, one-piece lubricious interior sheath.
Another object of the present invention is to provide an improved
thin-walled guiding catheter that has a multi-layered construction
of extruded material and that does not require adding any braiding
or strands of strengthening material therebetween.
Another object of this invention is the utilization of a relatively
rigid material in a thin-walled form within an elongated guiding
catheter suitable for intravascular uses.
Another object of the present invention is to provide an improved
intravascular guiding catheter that exhibits excellent torque
response or control and that is particularly resistant to kinking,
while still possessing the atraumatic properties and thinness
needed for an intravascular catheter.
These and other objects, features and advantages of this invention
will be clearly understood through a consideration of the following
detailed description.
BRIEF DESCRIPTION OF THE DRAWINGS
In the course of this description, reference will be made to the
attached drawings, wherein:
FIG. 1 is a perspective view, partially broken away, of a guiding
catheter according to this invention;
FIG. 2 is a longitudinal sectional view, generally along the line
2--2 of FIG. 1;
FIG. 3 is a transverse sectional view along the line 3--3 of FIG.
1;
FIG. 4 is a transverse sectional view along line 4--4 FIG. 2;
FIG. 5 is a longitudinal sectional view along the section of the
preferred guiding catheter at which the body portion ends and the
tip portion begins;
FIG. 6 is a perspective view illustrating extrusion of the
innermost, lubricious sheath according to this invention;
FIG. 7 is a perspective view illustrating the extrusion of the
intermediate, rigid sheath over the lubricious sheath; and
FIG. 8 is a perspective view illustrating extrusion of the
outermost, flexible sheath over the intermediate, rigid sheath and
illustrating, in phantom, a alternative assembly technique.
DESCRIPTION OF THE PARTICULAR EMBODIMENTS
FIG. 1 provides an illustration of the type of guiding catheter,
generally designated as 21, within which this invention is
embodied. Guiding catheter 21 includes an elongated tubular body
portion 22, a tip portion 23, and a hub 24. A longitudinal lumen 25
extends throughout the elongated tubular body 22 and the tip
portion 23, such longitudinal lumen 25 extending from a generally
coaxial bore 26 in the hub 24 to a distal orifice 27 within the tip
portion 23. Lubricious lumen 25 is sized and structured to
facilitate passage completely therethrough of an appropriate
intravascular catheter or the like (not shown), which would have an
outer diameter on the order of a "French 5" size, which is
approximately 0.008 inch.
Elongated body 22 includes an interior sheath 31, an intermediate,
generally rigid sheath 32, and a flexible outer sheath 33. Each
sheath 31, 32 and 33 is extremely thin-walled to the extent that
the elongated tubular body 22 is itself thin walled in order that
the lubricious lumen 25 may be as large in diameter as possible
while minimizing the outside diameter of the body 22. Tip portion
23 includes an interior, lubricious sheath 31a over which a
flexible outer sheath 33a is positioned.
Interior sheath 31,31a is made of a material exhibiting superior
lubricity, preferably a Teflon (duPont trademark) fluoroethylene
polymer, such as polytetrafluoroethylene (PTFE), fluoroethylene
copolymers having pendant perfluoro alkoxy groups (PFA), copolymers
of tetrafluorethylene and hexafluoropropylene (FEP), and copolymers
of ethylene and tetrafluoroethylene (Tefzel). Especially preferred
because of its superior lubricity and relative ease of extrusion is
the PFA type of fluoroethylene polymer, which is a derivative of
polytetrafluoroethylene that exhibits pendant perfluoro alkoxy
groups. These fluoroethylene polymers exhibit the following basic
structure: ##STR1## wherein X is fluorine, hydrogen or OR, wherein
R is fluoroalkyl such as a fluoromethane, and wherein n is on the
general order of 1000.
Intermediate sheath 32 is made of a material that, after extrusion,
is substantially stiff, and, in combination with the interior
sheath 31 and the flexible outer sheath 33, provides the
advantageous torque control properties that are characteristic of
this invention. Rigid intermediate sheath 32 is an extrusion grade
polymeric cylinder that had been formed by extrusion, preferably
onto a precision mandrel 34, which is typically a silver wire or
the like. Precision mandrel 34 is illustrated generally in FIGS. 6,
7 and 8, which also depict an outlet die 35 of an extruder.
Typically, such rigid polymeric materials will have a hardness
between approximately Shore D75 and Shore D85.
Typical suitable polymeric materials out of which rigid
intermediate sheath 32 can be extruded include polycarbonates,
polyethylene terephthalate (PET), polyethylene terephthalate glycol
(PETG), polyamides such as Nylon, which is a trademark of duPont,
polyacetal copolymers, such as Celcon (trademark) copolymers of
Celanese Corp., acetal homopolymers such as Delrin (trademark)
polymers of duPont, and the like.
Flexible outer sheath 33 is a polymeric material that had been
extruded as a sheath over the intermediate sheath 32. Such flexible
outer sheath 33 is made of a flexible polymeric material that is
biocompatible. Exemplary suitable materials include soft
polyurethanes, soft polyesters, low density polyethylene, and the
like. An example of a suitable flexible polyester is Hytrel, an
ester of polytetramethylene glyco and adipic acid with
1,4-butanediol as a chain extender. Typically, these flexible
polymeric materials will have a hardness between approximately
Shore D40 and Shore D60. Polyurethanes are the preferred materials
out of which the flexible outer sheath 33 is made.
Tip portion 23 is designed to minimize intimal trauma. Generally,
its interior sheath 31a is made of the same material as the
interior sheath 31 of the tubular body 22, while the flexible outer
sheath 33a thereof is preferably made of the same material as the
flexible outer sheath 33 of the tubular body 22. Because the tip
portion 23 excludes the more rigid, stiffening intermediate sheath
32, the tip portion 23 is particularly movable, flexible and
atraumatic.
Tip portion 23 may be an initially separate member that is affixed
to the elongated tubular body 22 by suitable means, such as by
heating, by other energy sources, and/or by adhesives or the like.
FIG. 2 depicts this type of assembly of these two separate
components. Such assembly can be assisted by the use of a length of
shrinkable tubing that is placed over the joint location prior to
and during the assembly operation in order to enhance the
smoothness and strength of the joint.
The preferred manner of forming the tip portion 23 first provides a
three-layered tubular body 22 that has a total length of that
desired for the completed guiding catheter 21. A distal end
section, typically on the order of four to five inches in length,
of the flexible outer sheath 33 is removed by convenient means,
such as by grinding or other treatment. A length of intermediate
sheath 32 is thus exposed for removal thereof. Especially efficient
and effective removal of the intermediate sheath 32 is effected by
treating same with a solvent therefor that will not dissolve away
the interior sheath 31 thereunder. Suitable solvents in this regard
include methyl ethyl ketone, pyrrole derivatives, and the like.
This procedure results in providing a tubular body 22a (FIG. 5)
which includes the interior sheath length 31a of the tip portion 23
that is continuous with and is the same integral extrudate as is
the interior sheath 31 of the tubular body 22a.
Thereafter, as illustrated in FIG. 5, a length of flexible outer
sheath 33a is secured onto and over the thus exposed interior
sheath length 31a. A preferred manner of accomplishing this result
includes sliding a length of flexible outer sheath tubing 33a over
the exposed interior sheath length 31a, such flexible outer sheath
tube length 33a having an internal diameter that is only very
slightly larger than the external diameter of the exposed interior
sheath length 31a, such interior diameter being just adequate to
permit the flexible outer sheath tube length 33a to be slid and/or
twisted over the interior sheath 31a. Appropriate adhesive material
may be interposed therebetween. Superior assembly is enhanced by
utilizing a length of shrinkable tubing 36 over the flexible outer
sheath tube length 33a in accordance with generally known
procedures in order to provide substantially uniform inwardly
radially directed forces to insure a secure assembly. This
procedure is particularly advantageous in view of the difficulty of
fusing or otherwise assembling interior sheath 31 to a separate
interior sheath 31a, especially when using highly resistant
materials such as a Teflon material, since by this approach, the
interior sheath 31 and interior sheath length 31a are a
single-piece, unitary tubing or sheath.
An alternative, substantially fuseless procedure is illustrated in
FIG. 8, wherein the tip portion 23b includes the continuous,
single-piece interior sheath, 31,31a on the order of that sheath of
the embodiment illustrated in FIG. 5, while also including a
continuous, single length flexible outer sheath 33,33b. In effect,
tip portion 23b is provided as an integral extension of the
flexible outer polymeric sheath 33, as well as of the lubricious
interior sheath 31. This is accomplished by extruding the interior
sheath 31,31a as a single continuous tube directly onto the
precision mandrel 34, extruding rigid intermediate sheath 32, and
thereafter extruding the flexible outer sheath length 33b directly
onto the interior sheath length 31a, while continued extrusion in
this regard results in the flexible outer sheath 33 being extruded
onto the intermediate sheath 32 as a unitary, single-piece
extension of the flexible outer sheath length 33b. A particularly
advantageous manner of accomplishing this alternative procedure is
as follows.
Interior sheath 31,31a is extruded onto the precision mandrel 34.
The rigid intermediate sheath 32 is modified so as to impart a gap
having an axial length substantially equal to the length of the tip
member 23b to be formed. If desired, a series of intermittent gaps
between lengths of rigid intermediate sheath 32 can be formed by
intermittently stopping the extrusion flow of the rigid
intermediate sheath polymer from the outlet die 35. A layer of
flexible outer sheath polymer is then extruded over the thus gapped
rigid polymer sheath 32, as well as over the intermediate gap(s)
therebetween in order to thereby extrude the flexible outer
polymeric material as an integral length that alternately overlies
the rigid polymer intermediate sheath 32 and the interior sheath
length 31a. The portion of this flexible polymer extrusion that
overlies the rigid polymer intermittent sheath 32 completes the
formation of the elongated tubular body 22b of this embodiment,
while the portion of this flexible polymer extrusion that overlies
the interior sheath length 31a combines with such interior sheath
length 31a to form the tip portion 23b of this embodiment. If a
plurality of gaps were formed during this extrusion, then
appropriate severance is accomplished in order to sever the distal
end of the tip portion 23b from the proximal end of an adjacent
tubular body portion 22b.
With more particular reference to the modification of the
intermediate sheath 32 so as to impart one or more gaps therein, at
least two different general approaches may be taken. One includes
removal of a length of the intermediate sheath 32, and the other
includes extruding the intermediate sheath 32 in an intermittent
manner. When proceeding by the removal approach, the intermediate
sheath 32 is extruded continuously over the interior sheath 31,31a,
and the removal is effected in any convenient manner, including
mechanical cutting, grinding, solvent dissolving and ultrasonic
removal (typically preceeded by freezing). A removal approach is
included within the preferred assembly procedure described
hereinabove. When proceeding by the intermittent extrusion
approach, extrusion of the intermediate sheath polymer proceeds
until the needed body length of intermediate sheath 32 has been
coated over the interior sheath 31, at which time this extruding is
interrupted or stopped while the mandrel 34 and the tip length
interior sheath 31a proceed to move beyond the outlet die 35 in
order to form a gap in the intermediate sheath 32, after which the
extrusion resumes until another body length of intermediate sheath
32 coats the body length interior sheath 31. Whether the removal
approach or the intermittent extrusion approach is used, the
unitary, single-piece flexible polymer outer sheath 33,33b is then
coated over the intermediate sheath(s) 32 and over the gap(s), as
generally illustrated in phantom in FIG. 8. The intermittent
extrusion approach provides the possibility for simultaneous
coextrusion of the interior sheath 31,31a of the intermediate
sheath 32, and of the flexible outer sheath 33,33b.
In order to be suitable for use in procedures utilizing
radiological techniques, the guiding catheter 21 should be
radiopaque. An exemplary manner of imparting this property to
guiding catheter 21 is to utilize a flexible polymeric material for
the outer sheath 23 that includes a radiopaque agent, such as
barium sulfate, bismuth subcarbonate or the like. This approach
provides what can be an advantageous feature for many uses, which
is that the tip portion 23 will be more visible by radiological
techniques than the rest of the guiding catheter 21, such enabling
the user to more easily focus on manipulations needed to maneuver
the tip portion through the cardiovascular system.
With more particular reference to details of the extrusion method,
the interior sheath 31 is extruded onto the precision mandrel 34
for a thickness of between about 0.003 inch and 0.005 inch at a
temperature of between about 350.degree. and 450.degree. F.
Preferably, this extrusion is then pretreated with an etching
solution, such as Polyetch, (a trademark of Matheson). Next, the
intermediate sheath polymer is extruded over the interior sheath
31, also at a temperature of between about 350.degree. and
400.degree. F. At these elevated temperatures, the rigid
intermediate material forms a bond with the interior sheath. At a
temperature between about 300.degree. and 350.degree. F., the
flexible outer sheath coating is extruded thereover. At the tip
portion, the flexible outer sheath is bonded to the interior
sheath. Extrusion at elevated temperatures softens the surface of
the sheath onto which a subsequent layer is being extruded in order
to enhance the extent that the respective sheaths are combined and
generally adhered together in order to form a more unitary body
that will be especially responsive to torque forces imparted
thereto and will exhibit advantageous thin-walled properties.
With reference to the hub 24, such will typically be joined the
proximal end of the elongated tube or body 22 by a suitable
material, such as an adhesive solvent that is a solvent which will
soften the materials utilized and adhere the hub 24 to the tubular
body 22. Typical solvents in this regard include tetrahydrofuran,
methyl ethyl ketone, acetone, and the like. Hub 24 is of a
structure that is suitable for the particular desired use of the
guiding catheter 21. Also associated with the hub 24 may be a
manipulator device (not shown) of generally known construction for
rotating and/or deflecting the guiding catheter 21 as desired in
order to assist in threading the tip portion 23 thereof through
branching blood vessels and the like.
An exemplary guiding catheter 21 prepared according to this
invention is one in which its lubricious lumen 25 has an inner
diameter that is able to slidingly receive and have passed
therethrough an intravascular catheter of the "French 5" size. The
total wall thickness of the tubular body 22 of the guiding catheter
21 would typically be on the order of 0.008 inch to 0.01 inch,
composed of between about 0.0005 to 0.003 inch as the lubricious
interior sheath 31, between about 0.0035 and 0.005 inch as the
rigid intermediate sheath 32, and between about 0.0045 and 0.003
inch as the flexible outer sheath 33.
It will be understood that the embodiments of the present invention
which have been described are merely illustrative of a few of the
applications of the principles of the present invention. Numerous
modifications may be made by those skilled in the art without
departing from the true spirit and scope of the invention.
* * * * *