U.S. patent number 5,120,323 [Application Number 07/730,373] was granted by the patent office on 1992-06-09 for telescoping guide catheter system.
This patent grant is currently assigned to Schneider (USA) Inc.. Invention is credited to Donald S. Baim, Rocky R. J. Campbell, Kevin L. Cronk, Rick L. Shockey.
United States Patent |
5,120,323 |
Shockey , et al. |
June 9, 1992 |
**Please see images for:
( Certificate of Correction ) ** |
Telescoping guide catheter system
Abstract
The guide catheter system for use in the treatment of coronary
artery disease includes a first single-lumen catheter of a
relatively large internal diameter to pass a second guide catheter
therethrough. The first guide catheter comprises an elongated
flexible tube having a stainless steel braid embedded in the wall
thereof for imparting desired torqueability characteristics to it.
The first guide catheter is intended to be inserted at an
appropriate point in the vascular system and then advanced until
its distal end reaches the coronary ostium. The second guide
catheter is fabricated by extruding a plastic, such as polyurethane
thermoplastic resin over a tubular Teflon.RTM. core and because it
is to be used within the lumen of the first catheter, it need not
include a braided structure within its walls to prevent it from
kinking. This allows the second catheter to be sufficiently slim to
permit it to be advanced into a coronary artery while allowing
fluids to be perfused between the outer wall of the second guide
and the inner wall of the first guide catheter while still
providing a sufficiently large inner lumen to pass a working
catheter, e.g., an angioplasty or atherectomy catheter. An
atraumatic tip is attached to the distal end of the second guide
catheter.
Inventors: |
Shockey; Rick L. (Eagan,
MN), Baim; Donald S. (Newton, MA), Cronk; Kevin L.
(Maple Grove, MN), Campbell; Rocky R. J. (Maple Plain,
MN) |
Assignee: |
Schneider (USA) Inc.
(Minneapolis, MN)
|
Family
ID: |
27040940 |
Appl.
No.: |
07/730,373 |
Filed: |
July 11, 1991 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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464324 |
Jan 12, 1990 |
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Current U.S.
Class: |
604/528; 600/434;
606/194 |
Current CPC
Class: |
A61M
25/01 (20130101); A61B 2017/22001 (20130101); A61M
2025/0175 (20130101); A61M 25/0169 (20130101) |
Current International
Class: |
A61M
25/01 (20060101); A61B 17/22 (20060101); A61M
025/00 () |
Field of
Search: |
;606/192,194
;604/96-103,265,280,282 ;128/656-658,772 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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277366 |
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Aug 1988 |
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EP |
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303487 |
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Feb 1989 |
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EP |
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Primary Examiner: Yasko; John D.
Assistant Examiner: Cermak; Adam J.
Attorney, Agent or Firm: Haugen and Nikolai
Parent Case Text
This is a continuation of copending U.S. application Ser. No.
07/464,324, filed on Jan. 12, 1990 now abandoned.
Claims
What is claimed is:
1. A method of performing recanalization of a stenosed coronary
artery of interest comprising the steps of:
introducing a first elongated, hollow, flexible, plastic,
relatively large diameter, reinforced-wall torque-transmitting
guide catheter having a proximal end and a distal end at a
predetermined location in the vascular system and advancing the
first guide catheter until the distal end thereof reaches the
coronary ostia;
inserting a second, elongated, hollow, flexible, plastic,
relatively smaller diameter unreinforced guide catheter having a
tubular core a polytetrafluoroethylene polymeric material sheathed
in an outer cylindrical coating of a second polymeric material and
a distal tip member of a material of relatively low durometer
relative to the other materials of the second guide catheter
affixed to the distal end of the second guide catheter, wherein the
tip member is further characterized by a distal end shaped to
encounter and minimize damage to the endothelial lining of coronary
artery of interest by the advancing second guide catheter;
advancing the second guide catheter until the distal end of the
second catheter passes beyond the distal end of the first guide
catheter and into the coronary artery of interest adjacent the
stenosis to be canalized;
slidably introducing a working catheter having a proximal end and a
distal end into the hollow tubular core of the second guide
catheter and advancing the working catheter therealong until the
distal end of the working catheter passes through and extends
beyond the distal end of the second guide catheter and into the
stenosed area of the coronary artery of interest; and
using the working catheter to accomplish recanalization.
2. The method of claim 1 wherein the outside diameter of the second
guide catheter is in the range of from about 6.5 French to 3 French
and the inside diameter of the first guide catheter is in the range
of from about 7 French to 3.5 French.
3. A telescoped dual guide catheter system for use in performing
artery transluminal angioplasty or atherectomy procedures in a
coronary artery of interest having the ability to navigate coronary
arteries comprising:
an outer guide catheter comprising an elongated, flexible plastic
tuber having a proximal end and a distal end, having an outside
diameter small enough to pass through the arterial vascular system
from an introducer site to the coronary ostia, the outer guide
catheter further describing an internal lumen of a relatively large
size extending from the proximal end to the distal end and having a
tube wall characterized by reinforcing means internal to the tube
wall for providing the necessary torque transmission required to
enable routing of the outer guide catheter through the arterial
vascular system; and
an inner elongated guide catheter adapted to be telescopingly
received within and passed through the lumen of the outer guide
catheter and including flexible tubular core of a lubricous
material constructed without reinforcing means surrounded by an
outer coating of a polymeric material and having a proximal end, a
distal end and an outside diameter sufficiently small to fit with a
predetermined clearance within the lumen of the outer guide
catheter;
wherein the distal end of the unreinforced inner guide catheter is
adapted to pass beyond the distal end of the outer guide catheter
and navigate vascular areas beyond the distal end of the outer
guide catheter through which the outer guide catheter itself cannot
be safely passed including the area beyond the coronary ostia into
a coronary artery of interest to be recanalized; and
wherein the lumen of the tubular core of the inner guide catheter
is of sufficient diameter to pass a working catheter
therethrough.
4. The telescoped dual guide catheter system of claim 3 further
including a tubular tip member of a polymer material of relatively
low durometer affixed to the distal end of the inner guide
catheter, wherein the tip member is further characterized by a
rounded distal end to encounter and minimize damage to the
endothelial lining of the vascular system including the coronary
artery of interest.
5. The telescoped dual guide catheter system of claim 4
wherein the reinforcing means internal to the tube wall of the
outer guide catheter is braided wire;
wherein the core of the inner guide catheter is
polytetrafluoroethylene; and
wherein the outer coating comprises a blend of polyurethane.
6. The telescoped dual guide catheter system of claim 5 wherein the
polymer tip material is a relatively soft polyurethane.
7. The telescoped dual guide catheter as in claim 6 further
including a molded plastic hub affixed to the proximal end of the
inner guide catheter.
8. The telescoped dual guide catheter of claim 6 wherein the wall
of the inner catheter is thinner than the wall of the outer
catheter tube.
9. The telescoped dual guide catheter as in claim 5 further
including a molded plastic hub affixed to the proximal end of the
inner guide catheter.
10. The telescoped dual guide catheter of claim 5 wherein the wall
of the inner catheter is thinner than the wall of the outer
catheter tube.
11. The telescoped dual guide catheter system of claim 4 wherein
the polymer tip material is a relatively soft polyurethane.
12. The telescoped dual guide catheter as in claim 4 further
including a molded plastic hub affixed to the proximal end of the
inner guide catheter.
13. The telescoped dual guide catheter system of claim 3 wherein
the outside diameter of the smaller inner guide catheter is in the
range of from about 6.5 French to 3 French and the corresponding
inside diameter of the large outer guide catheter is in the range
of from about 7 to 3.5 French.
14. The telescoped dual guide catheter as in claim 13 further
including a molded plastic hub affixed to the proximal end of the
inner guide catheter.
15. The telescoped dual guide catheter of claim 13 wherein the wall
of the inner catheter is thinner than the wall of the outer
catheter tube.
16. The telescoped dual guide catheter system of claim 3
wherein the reinforcing means internal to the tube wall of the
outer guide catheter is braided wire;
wherein the core of the inner guide catheter is
polytetrafluoroethylene; and
wherein the outer coating comprises a blend of polyurethane.
17. The telescoped dual guide catheter as in claim 3 further
including a molded plastic hub affixed to the proximal end of the
inner guide catheter.
18. The telescoped dual guide catheter of claim 3 wherein the wall
of the inner catheter is thinner than the wall of the outer
catheter tube.
19. A telescoped dual guide catheter system for use in performing
artery transluminal angioplasty or atherectomy procedures in a
coronary artery of interest having the ability to navigate coronary
arteries comprising:
an outer guide catheter comprising an elongated, flexible plastic
tube having a proximal end and a distal end, having an outside
diameter small enough to pass through the arterial vascular system
from an introducer site to the coronary ostia, the outer guide
catheter further describing an internal lumen of a relatively large
size extending from the proximal end to the distal end and having a
tube wall characterized by a braided metal reinforcing layer
internal to the tube wall for providing the necessary torque
transmission required to enable routing of the first guide catheter
through the arterial vascular system; and
an inner elongated guide catheter adapted to be telescopingly
accommodated by, received within, and passed through the lumen of
the outer guide catheter and including an unreinforced flexible
tubular core of a lubricous polytetrafluoroethylene surrounded by
an outer coating of a polyurethane blend material and having a
proximal end, a distal end and an outside diameter sufficiently
small to fit with a predetermined clearance within the lumen of the
outer guide catheter;
wherein the distal end of the unreinforced inner guide catheter is
adapted to pass beyond the distal end of the outer guide catheter
and navigate vast vascular areas beyond the distal end of the outer
guide catheter through which the outer guide catheter itself cannot
be safely passed including the area beyond the coronary ostia into
a coronary artery of interest to be recanalized;
wherein the lumen of the tubular core of the inner guide catheter
is of sufficient diameter to pass a working catheter
therethrough;
a tubular tip member of a polymer material of relatively low
durometer polyurethane affixed to the distal end of the inner guide
catheter, the tip member being further characterized by a rounded
distal end to encounter and minimize damage to the endothelial
lining of the coronary artery of interest.
Description
BACKGROUND OF THE INVENTION
I. Field of the Invention
This invention relates generally to improved catheter apparatus for
facilitating the recanalization of a stenosed coronary artery and
more particularly to an improved guide catheter system whereby a
guide catheter member can be advanced beyond the coronary ostium
and into the coronary artery itself up to the point of the
stenosis.
II. Discussion of the Prior Art
In treating coronary artery disease, a variety of surgical
techniques are employed to recanalize an occluded or partially
occluded artery segment without requiring open heart surgery. Using
the technique pioneered by A. Gruntzig, a catheter having an
expander (balloon) at its distal end is routed through the vascular
system and ultimately into the coronary artery with the balloon
being juxtaposed with the stenotic lesion. Once so positioned, the
balloon is inflated to compress the plaque into the wall of the
blood vessel, thus restoring patency.
In another procedure, referred to as an atherectomy, a catheter
having a rotatable cutter at its distal tip is advanced through the
vascular system and when the tip is made to abut the atheroma, a
motor at the proximal end of the catheter is used to drive the
cutter to surgically "tunnel" through the lesion. In this regard,
reference is made to the Rydell U.S. Pat. No. 4,784,636, assigned
to applicant's assignee.
Still others have incorporated a fiber optic bundle in a catheter
and a laser is used to burn through the plaque comprising the
arterial blockage. In this regard, reference is made to the Moore
et al U. S. Pat. No. 4,669,465, assigned to GV Medical, Inc., of
Minneapolis, Minn.
The foregoing are exemplary of working catheters, i.e., the
catheters that are directly involved in the recanalization through
expansion, excision or ablation. To properly position the working
catheter, it is also necessary that a guide catheter be utilized. A
guide catheter of the prior art typically comprises an elongated,
flexible tube having an internal lumen sufficiently large to
receive and pass the working catheter therethrough. In that the
catheters are generally introduced into the femoral artery and then
advanced through the vascular system to the heart, the guide
catheter must possess a characteristic of "torqueability" meaning
that it can transmit a twisting force applied at its proximal end
to the distal end to facilitate the ability to steer it through the
appropriate vascular branches. The torqueability characteristic is
achieved by the appropriate choice of materials for the guide
catheter shaft or by incorporating a braided sheath of wire strands
embedded in the wall of the guide catheter. Those wishing further
information concerning the construction of a typical prior art
guide catheter are referred to the Stevens U.S. Pat. No. 3,485,234,
assigned to the Cordis Corporation of Miami, Fla.
When it is considered that the lumen of the guide catheter must be
large enough to pass the working catheter and that the guide
catheter shaft must exhibit acceptable torqueability and stiffness
characteristics, it tends to dictate a guide catheter having a
relatively large outside diameter. In fact, it has not been
possible in the past to advance the distal end of the conventional
guide catheter beyond the coronary ostium. Where the site of the
lesion in the coronary artery is several centimeters beyond the
ostium and it becomes necessary during the recanalization procedure
to exchange working catheters, damage may be done to the delicate
tissue of the intima.
SUMMARY OF THE INVENTION
In accordance with the present invention, a system of guide
catheters is provided whereby a guide catheter can be configured
sufficiently small in outside diameter that it will pass distally
of the ostium into the coronary artery to be treated while
maintaining a sufficiently large internal diameter for allowing a
working catheter to be passed therethrough and guided thereby. More
specifically, the guide catheter system includes a somewhat
conventional guide catheter of the type described above, but
instead of passing the working catheter directly through its lumen,
a second guide catheter is telescopingly received within the lumen
of the first guide catheter. The second guide catheter comprises an
elongated thin-wall tube of polytetrafluoroethylene (Teflon.RTM.)
which is coated on its exterior with a blend of polyurethanes.
Because the second guide catheter is to be passed through the lumen
of the first guide catheter, it does not require a braided layer to
provide the torqueability necessary to route the guide catheter
from its femoral artery entry point to the heart. Instead, it
tracks the lumen of the first guide catheter. Because the need for
a braided layer is obviated, it can be made of a sufficiently thin
wall that its outside diameter is sufficiently small that the
second guide catheter can be advanced beyond the ostium and into
the coronary artery itself. To minimize damage to the endothelial
layer, the second guide catheter is equipped with a soft tip which
is appropriately rounded to avoid sharp edges which can damage the
arterial wall. The soft tip may preferably be formed from a
polyurethane resin exhibiting low durometer as compared to the
durometer of the polyurethane blend coating the Teflon tubular
core. By lining the second guide catheter with the Teflon core, its
trackability and pushability property is enhanced. The Teflon layer
provides a low coefficient of friction with the working catheter to
be inserted.
With the second guide catheter advanced so that its distal end
portion is contained within the coronary artery to be treated, it
provides backup support for the blood vessel during the
recanalization procedure and allows repeated exchanges of working
catheters with a minimum of damage to the intima.
The foregoing features, objects and advantages of the invention
will become more apparent to those skilled in the art from the
following detailed description of a preferred embodiment,
especially when considered in conjunction with the accompanying
drawings in which like numerals in the several views refer to
corresponding parts.
DESCRIPTION OF THE DRAWINGS
FIG. 1 is a side view, partially cross-sectioned of the guide
catheter system of the present invention; and
FIG. 2 is a diagram illustrating the use of the present invention
in recanalizing a stenosed coronary arterial blood vessel.
DESCRIPTION OF THE PREFERRED EMBODIMENT
Referring first to FIG. 1, there is indicated generally by numeral
10 the guide catheter system in accordance with the present
invention. It is seen to include a first, relatively large diameter
guide catheter 12, comprising an elongated, flexible plastic tube
which would typically be approximately 100 cms. in length and
fabricated primarily from a blend of polyurethanes and containing a
braided wire sheath 14 within its walls. In that the outer guide
catheter 12 is intended to be routed through the vascular system
from a peripheral site such as an incision into the femoral artery,
the wire braid affords the desirable torque properties whereby
twisting the proximal end 16 will transmit a corresponding torque
to the distal end 18 of the catheter 12. The catheter 12 may be in
the range of from about 9 French to 5 French and designed to have
an internal lumen in the range of from 7 French to 3.5 French.
Bonded to the proximal end 16 of the outer catheter 12 is a
conventional catheter hub 20. The catheter structure thus far
described may be produced in accordance with the Stevens U.S. Pat.
No. 3,485,234 which describes a manufacturing process whereby a
catheter is produced having a precisely dimensioned lumen and a
braided wire sheath disposed entirely within the plastic comprising
the catheter's wall.
To reduce the likelihood and/or extent of trauma to the endothelial
lining of the blood vessels through which the outer catheter 12 is
routed, it is preferably provided with an atraumatic tip 22 which
is appropriately attached to the end of the outer tubing member.
The soft tip 22 will typically be formed from a polyurethane blend
exhibiting a lower durometer than the plastic comprising the
remainder of the catheter. It may be attached and otherwise
configured as set out in the Van Tassel et al. U.S. Pat. No.
4,531,943 assigned to applicant's assignee.
Coaxially disposed and loosely fitting within the lumen 24 of the
first or outer catheter 12 is a second catheter 26 which is of a
somewhat greater length than the first catheter 12. The body of the
catheter 26 comprises an internal tubular core 28 which is made
from polytetrafluoroethylene (Teflon.RTM.) having a wall thickness
of approximately 0.0005 inches The Teflon tube, while supported on
a cylindrical mandrel, is then coated with a suitable plastic,
preferably a blend of polyurethanes so that the composite outside
diameter is in the range of from 8 French to 3 French.
As mentioned above, the inside diameter of the outer guide catheter
12, if designed to be 7 French, leaves a predetermined clearance
between the two when a second catheter 26 of, say, 6 French, is
telescopingly received within the lumen 24 of the outer catheter
12. This permits the perfusion or aspiration of liquids through the
annular gap between inner wall of the outer catheter 12 and the
outer wall of the inner catheter 26.
Appropriately bonded to the distal end portion of the second or
inner catheter 26 is an atraumatic tip 30 again formed from a
suitable plastic material exhibiting a low durometer rating.
The catheter 26, being 6 French, may have an internal diameter of
0.063 inches which is sufficiently large to pass a working catheter
(not shown) therethrough. As mentioned above, the working catheters
employed may include those for angiography, atherectomy, as well as
various pressure monitoring or fiber optic devices.
Shown threaded through the lumen of the inner tubular catheter 26
is an elongated flexible, helically wound stainless steel guidewire
32.
Having described the constructional features of the guide catheter
system of the present invention, consideration will next be given
to its mode of use. In this regard, reference is made to FIG. 2
which diagrammatically depicts the various coronary arterial blood
vessels, both anterior and posterior with the remainder of the
heart eliminated. Thus, numeral 34 identifies the femoral artery
leading to the descending aorta 36, the aortic arch 38 and the
aortic valve 40. Located adjacent the aortic arch 38 and slightly
above the valve 40 is the left coronary ostium 42 and the right
coronary ostium 44.
Leading away from the ostium 42 is the left coronary artery 46
which joins to the circumflex branch 48 from which the obtuse
marginal branch 50 and the intermediate branch 52 extend.
The left anterior descending artery is identified by numeral 54 and
branching from it are the septal arteries 56 and 58.
Extending from the right coronary ostium 44 is the right coronary
artery 60 which leads to the posterior descending artery 62. Let it
be assumed that a stenosis exists at 64 in the left anterior
descending artery 54 and that it is desired to treat the lesion
with an angioplasty balloon-type working catheter. In carrying out
the procedure, an incision is made and an introducer (not shown) is
inserted into the femoral artery 34. The first catheter 12 is then
passed retrograde up the descending aorta 36 and beyond the aortic
arch 38 until its distal tip 22 abuts the coronary ostium 42. Next,
a guidewire 32 is passed through the lumen of the first guide
catheter 12 and maneuvered by twisting and advancing distally until
the guidewire passes down the left anterior descending artery 54
and beyond the location of the lesion 64. Once the guidewire 32 is
so positioned, the telescoping guide catheter 26 is passed over the
wire 32 by feeding the distal tip 30 over the guidewire and feeding
it through the hub 20 of the outer guide catheter 12 and thence
through the lumen 24 thereof until it exits the distal end 18 of
the outer catheter through the left coronary ostium 42 and down the
left anterior descending branch 54. Once the distal tip 30 of the
inner telescoping guide catheter 26 is proximate the site of the
lesion, the working catheter (not shown) with its distal balloon
may now be fed through the lumen 31 of the inner guide catheter and
over the guide wire 32. Because the interior wall of the inner
guide catheter is lined with a layer of a lubricious plastic, such
as Teflon, the coefficient of friction between the working catheter
and the wall of the inner guide catheter is low, thus enhancing the
trackability of the working catheter through the lumen of the inner
guide catheter 26. Once the distal balloon of the working catheter
is advanced across the stenosis, dilatation of the affected blood
vessel can take place. Once the balloon has been advanced across
the lesion, it is the physician's choice whether to pull the inner
guide back into the lumen of the outer guide or not.
It may also occur that the physician will want to withdraw one
working catheter in favor of a replacement working catheter. By
leaving the internal guide catheter 26 in position, the exchange
may take place without repeatedly drawing the working catheter back
and forth over the endothelial lining of the blood vessel. Instead,
the arterial branch remains supported by the guide catheter 26
during the exchanges.
This invention has been described herein in considerable detail in
order to comply with the Patent Statutes and to provide those
skilled in the art with the information needed to apply the novel
principles and to construct and use such specialized components as
are required. However, it is to be understood that the invention
can be carried out by specifically different equipment and devices,
and that various modifications, both as to the equipment details
and operating procedures, can be accomplished without departing
from the scope of the invention itself.
* * * * *