U.S. patent application number 09/854046 was filed with the patent office on 2002-06-20 for catheter with flexible intermediate section.
This patent application is currently assigned to Eclipse Surgical Technologies. Invention is credited to Javier, Manuel A. JR., Kesten, Randy J., Payne, Sam G., Pearce, Stephen B..
Application Number | 20020077654 09/854046 |
Document ID | / |
Family ID | 25212575 |
Filed Date | 2002-06-20 |
United States Patent
Application |
20020077654 |
Kind Code |
A1 |
Javier, Manuel A. JR. ; et
al. |
June 20, 2002 |
Catheter with flexible intermediate section
Abstract
An intraluminal catheter with an elongated tubular shaft with
proximal, intermediate, and distal shaft sections for positioning a
therapeutic or diagnostic device within a patient's body region
such as a heart chamber. The intermediate shaft section has greater
flexibility than the proximal or distal shaft sections, and is
preferably of sufficient flexibility to easily assume the curvature
of the patient's aortic arch, and reduce the force of contact
between the catheter distal end and tissue defining the patient's
body region to thereby reduce restriction on the rotation of the
catheter. The flexible intermediate shaft section is preferably of
a length to occupy a significant portion of the aortic arch, and
the catheter overall length is preferably sufficient to have a
catheter proximal extremity extending out of the patient and a
distal extremity extending at least into an aortic passageway
adjacent the patient's left ventricle.
Inventors: |
Javier, Manuel A. JR.;
(Santa Clara, CA) ; Pearce, Stephen B.; (Fremont,
CA) ; Payne, Sam G.; (Santa Clara, CA) ;
Kesten, Randy J.; (Mountain View, CA) |
Correspondence
Address: |
Eclipse Surgical Technologies
1049 Kiel Court
Sunyvale
CA
94085
US
|
Assignee: |
Eclipse Surgical
Technologies
|
Family ID: |
25212575 |
Appl. No.: |
09/854046 |
Filed: |
May 11, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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09854046 |
May 11, 2001 |
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09546724 |
Apr 11, 2000 |
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09546724 |
Apr 11, 2000 |
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09123880 |
Jul 28, 1998 |
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09123880 |
Jul 28, 1998 |
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08813503 |
Mar 7, 1997 |
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Current U.S.
Class: |
606/194 |
Current CPC
Class: |
A61M 25/0054 20130101;
A61B 2017/00247 20130101; A61B 2018/00392 20130101; A61M 25/0662
20130101 |
Class at
Publication: |
606/194 |
International
Class: |
A61M 029/00 |
Claims
What is claimed is:
1. An intraluminal catheter for positioning an intravascular device
within a patient's body cavity, comprising: a) a tubular proximal
shaft section; b) a tubular intermediate shaft section being distal
to the proximal shaft section, having a flexibility that is greater
than that of the proximal shaft section; c) a tubular distal shaft
section being distal to the intermediate shaft section, having a
distal end, and having a flexibility that is less than that of the
intermediate shaft section; d) a port on the distal end of the
distal shaft section; and e) a lumen extending to and in fluid
communication with the port in the distal end of the distal shaft
section.
2. The intraluminal catheter of claim 1 wherein the catheter is a
delivery catheter.
3. The intraluminal catheter of claim 1 wherein the catheter is a
guiding catheter.
4. The intraluminal catheter of claim 1 wherein the intermediate
shaft section has a length at least about 2 to about 8 times the
length of the distal shaft section.
5. The intraluminal catheter of claim 1 wherein the intermediate
shaft section has a length about 4 times the length of the distal
shaft section.
6. The intraluminal catheter of claim 1 wherein the intermediate
shaft section has a length of about 5 to about 50 cm.
7. The intraluminal catheter of claim 1 wherein the intermediate
shaft section has a length of about 20 to about 30 cm.
8. The intraluminal catheter of claim 1 wherein the intermediate
shaft section has a length sufficient to occupy a significant
portion of an aortic arch of the patient.
9. The intraluminal catheter of claim 1 wherein the distal shaft
section has a shape at the distal end configured to facilitate
directing an intravascular device disposed within the lumen of the
catheter to a desired region within the body cavity.
10. The intraluminal catheter of claim 1 wherein the distal shaft
section includes a nontraumatic distal tip.
11. The intraluminal catheter of claim 1 wherein the catheter has a
length sufficient to have a proximal extremity extending out of the
patient and a distal extremity extending at least into an ascending
aortic passageway adjacent a left ventricle of the patient.
12. The intraluminal catheter of claim 1 wherein the intermediate
section has a flexibility sufficient to allow the intermediate
section to assume a curvature of an aortic arch without the
catheter exterting significant pressure on a wall defining the
patient's body cavity.
13. The delivery catheter of claim 2 wherein the intermediate shaft
section has a flexibility such that a load of about 5 to about 30
grams is required to deflect a cantilevered length of the catheter
shaft 12.7 mm from the fixed end a distance of 1 mm.
14. The delivery catheter of claim 2 wherein the intermediate shaft
section has a flexibility such that a load of about 10 to about 20
grams is required to deflect a cantilevered length of the catheter
shaft 12.7 mm from the fixed end a distance of 1 mm.
15. The delivery catheter of claim 2 wherein the proximal and
distal shaft sections have a flexibility such that a load of about
20 to about 70 grams is required to deflect a cantilevered length
of the catheter shaft 12.7 mm from the fixed end a distance of 1
mm.
16. The delivery catheter of claim 2 wherein the proximal and
distal shaft sections have a flexibility such that a load of about
30 to about 50 grams is required to deflect a cantilevered length
of the catheter shaft 12.7 mm from the fixed end a distance of 1
mm.
17. The delivery catheter of claim 2 wherein the lumen is
configured to slidably receive a diagnostic or therapeutic
device.
18. The guiding catheter of claim 3 wherein the intermediate shaft
section has a flexibility such that a load of about 60 to about 200
grams is required to deflect a cantilevered length of the catheter
shaft 12.7 mm from the fixed end a distance of 1 mm.
19. The guiding catheter of claim 3 wherein the intermediate shaft
section has a flexibility such that a load of about 100 to about
150 grams is required to deflect a cantilevered length of the
catheter shaft 12.7 mm from the fixed end a distance of 1 mm.
20. The guiding catheter of claim 3 wherein the proximal and distal
shaft sections have a flexibility such that a load of about 30 to
about 100 grams is required to deflect a cantilevered length of the
catheter shaft 12.7 mm from the fixed end a distance of 1 mm.
21. The guiding catheter of claim 3 wherein the proximal and distal
shaft sections have a flexibility such that a load of about 50 to
about 80 grams is required to deflect a cantilevered length of the
catheter shaft 12.7 mm from the fixed end a distance of 1 mm.
22. The guiding catheter of claim 3 wherein the lumen thereof is
configured to slidably receive a delivery catheter.
23. A catheter system for performing diagnostic or therapeutic
procedures within a patient's body, comprising: a) a guiding
catheter; b) a delivery catheter slidably disposed within the
guiding catheter lumen, comprising: i) a tubular proximal shaft
section; ii) a tubular intermediate shaft section being distal to
the proximal shaft section, having a flexibility that is greater
than that of the proximal shaft section; iii) a tubular distal
shaft section being distal to the intermediate shaft section,
having proximal and distal ends, having a port on the distal end,
and having a flexibility that is less than that of the intermediate
shaft section; and iv) a lumen extending to and in fluid
communication with the port on the distal end; and c) a therapeutic
or diagnostic device slidably disposed within the delivery catheter
lumen.
24. The catheter system of claim 23 wherein the guiding catheter
comprises: a) a tubular proximal shaft section; b) a tubular
intermediate shaft section being distal to the proximal shaft
section, having a flexibility that is greater than that of the
proximal shaft section; c) a tubular distal shaft section being
distal to the intermediate shaft section, having proximal and
distal ends, and having a flexibility that is less than that of the
intermediate shaft section; d) a port on the distal end of the
distal shaft section; and e) a lumen extending to and in fluid
communication with the port on the distal end.
25. The catheter system of claim 23 wherein the delivery catheter
has an overall length about 5 cm to about 30 cm longer than an
overall length of the guiding catheter.
26. A catheter system for performing diagnostic or therapeutic
procedures within a patient's body, comprising: a) a delivery
catheter for positioning a therapeutic or diagnostic device within
a patient's left ventricle configured to be slidably advanced over
a guidewire, comprising: i) a tubular proximal shaft section; ii) a
tubular intermediate shaft section being distal to the proximal
shaft section, having a flexibility that is greater than that of
the proximal shaft section; iii) a tubular distal shaft section
being distal to the intermediate shaft section, having a distal end
with a port on the distal end, and having a flexibility that is
less than that of the intermediate shaft section; and iv) a lumen
extending to and in fluid communication with the port on the distal
end; b) a therapeutic or diagnostic device positioned within the
delivery catheter lumen and extending out the distal end port.
27. A method for performing a diagnostic or therapeutic procedure
within a patient's body, comprising: a) advancing a delivery
catheter having a flexible tubular intermediate shaft section until
the flexible tubular intermediate shaft section occupies a
significant portion of the aortic arch, and until a distal shaft
section of the delivery catheter extends into the patient's left
ventricle; b) advancing an elongated diagnostic or therapeutic
device having an operative distal end through the delivery catheter
and out a port in a distal end of the delivery catheter so that the
operative distal end engages the desired region of the patient's
endocardial layer; and c) performing a diagnostic or therapeutic
procedure within the left ventricle.
28. The method of claim 27 further including, before step (a), the
steps comprising: a) providing a guiding catheter having a flexible
tubular intermediate shaft section and introducing the guiding
catheter into a peripheral artery of the patient; b) advancing the
guiding catheter through the patient's arterial system until the
flexible tubular intermediate shaft section occupies a significant
portion of the aortic arch, and until a distal shaft section of the
guiding catheter extends at least into an aortic passageway
adjacent the patients left ventricle; c) advancing the delivery
catheter having a flexible tubular intermediate shaft section
through the distal shaft section of the guiding catheter.
Description
BACKGROUND OF THE INVENTION
[0001] This invention is directed to an elongated catheter adapted
to facilitate delivery of a therapeutic or diagnostic device into a
body cavity such as the left ventricle of a patient's heart, and
particularly for the treatment of myocardial tissue experiencing
ischemic conditions by revascularization of such tissue.
[0002] Myocardial revascularization typically involves formation of
one or more channels in a patient's heart wall defining the heart
chamber to treat a patient's ischemic myocardial tissue therein.
The first trials of the revascularization process was made by
Mirhoseini et al. See for example the discussions in Lasers in
General Surgery (Williams & Wilkins; 1989), pp 216-223. Another
early disclosure of this procedure is found in U.S. Pat. No.
4,658,817 (Hardy). Both of these references describe
revascularization procedures which require the chest wall to be
opened and which include formation of the revascularization
channels through the epicardium, myocardium and endocardium, i.e.
the entire heart wall.
[0003] Copending application Ser. No. 08/368,409, filed on Dec. 30,
1994, which is incorporated herein in its entirety, describes an
intravascular system for percutaneous transmyocardial
revascularization (PTMR) which is introduced into a peripheral
artery and advanced through the patient's arterial system into the
left ventricle of the patient's heart. The revascularization
channels are formed through the endocardium and into the myocardium
from within the left ventricle. This procedure eliminates the need
of the prior intraoperative procedures which require opening the
chest cavity and penetrating the entire heart wall to form a
channel through the endocardium into the myocardium.
[0004] While the percutaneous method and system for introducing the
revascularization device developed by Aita et al. was a substantial
advance, one of the difficulties in forming revascularization
channels from within a patient's left ventricle by means of a
percutaneously introduced revascularization system was to
accurately direct the distal tip of the channel forming device to a
desired region of the patient's endocardium and to maintain the
placement of the distal end of the channel forming device against a
desired region of the ventricular wall at a proper angle while the
heart was beating. Copending application, Ser. No 08/646,856 filed
May 8, 1996, which is incorporated herein in its entirety,
describes an intravascular system using one or more delivery
catheters which may have a preshaped or shapeable distal
extremities to facilitate directing a therapeutic or diagnostic
device slidably disposed within the catheter lumen toward the
region of the endocardium where the procedure is to be
performed.
[0005] What has been needed is a guiding or delivery catheter with
the maneuverability desired for advancing through the patient's
vasculature yet having sufficient strength and rigidity to support
a channel forming device within the patient's heart chamber. The
present invention satisfies these and other needs.
SUMMARY OF THE INVENTION
[0006] The present invention is directed to intraluminal catheters
which aid in positioning a therapeutic or diagnostic device within
a patient's body region such as a heart chamber. The intraluminal
catheter of the invention generally has an elongated tubular shaft
with proximal, intermediate, and distal shaft sections. The
intermediate shaft section has greater flexibility than the
proximal or distal shaft sections. The distal shaft section may
have equal or greater flexibility than the proximal shaft
section.
[0007] The relative flexibility or the inverse stiffness of the
various shaft sections may be achieved with conventional techniques
used in catheter design, including selection of materials and wall
thickness, and the use of reinforcing means such as strands, coils
and the like. For example, a thin walled intermediate shaft section
would have high flexibility relative to thicker walled proximal or
distal shaft sections made from the same or similar materials.
Alternatively, the material used in the intermediate shaft section
may be inherently more flexible than a different material used in
the proximal or distal shaft sections. Likewise, the catheter shaft
sections may be formed of the same material with the distal and
proximal sections provided with reinforcing stands or coils.
[0008] In accordance with one aspect of the invention, the
intraluminal catheter is a delivery catheter for directing an
elongated intraluminal device to a desired region within the
patient's body such as the patient's heart chamber. The catheter
shaft has proximal and distal ends, and a lumen extending to and in
fluid communication with a port in the distal end of the catheter.
The port and inner lumen are configured to slidably receive an
elongated therapeutic or diagnostic device. A typical delivery
catheter device of the invention is particularly suitable for
delivery of an elongated device for forming a channel into the wall
defining the heart chamber or a device for performing other
ablation treatments and diagnosis.
[0009] For the percutaneous delivery of therapeutic or diagnostic
devices into a patient's left ventricle the delivery catheter is of
a length sufficient to have a proximal extremity extending out of
the patient and a distal extremity extending into the patient's
left ventricle. The overall length of the catheter is preferably
about 100 cm to about 120 cm, and typically about 105 cm. The
length of the intermediate section is about 5 to about 50 cm, and
preferably about 20 cm to about 30 cm, so that it extends through
at least a substantial portion of a human patient's aortic arch.
The length of the distal section is about 2 to about 10 cm, and
preferably about 4 cm to about 8 cm to ensure that the distal end
of the catheter shaft extends into the left ventricle of the
patient's heart. Therefore, the intermediate shaft section is a
length at least about 2 to about 8, and preferably about 4 times
the length of the distal shaft section.
[0010] In a presently preferred embodiment, the distal shaft
section is relatively short when compared to the intermediate shaft
section. Additionally, the proximal shaft section is relatively
long compared to the intermediate and distal shaft sections. When
the distal end of the catheter has been advanced through a
patient's aortic passageway and into the left ventricle or slightly
downstream thereof, the more flexible intermediate shaft section
occupies aortic arch, or at least a significant portion thereof,
slightly downstream of the aortic valve. The relatively stiff
proximal shaft section extends from the proximal extremity of the
delivery catheter outside the patient to a point within the
descending aorta downstream of the aortic arch. The distal shaft
section extends from the flexible intermediate shaft section to the
distal end of the delivery catheter within the left ventricle.
[0011] The catheter of the invention is particularly suitable for
delivery of therapeutic or diagnostic devices such as laser based
optical fiber systems for forming channels within the wall of the
patient's heart, i.e. PTMR. The optical fiber system which is
adapted to emit laser energy from its distal end, is slidably
disposed within the lumen of the delivery catheter and is of a
length sufficient to extend out the port in the distal end of the
catheter to engage tissue of the endocardium while forming the
channel or performing other types of procedures. The distal end of
the catheter is preferably shaped so that when positioned within
the patient's heart chamber, it provides the desired orientation
for the delivered therapeutic or diagnostic device toward the
region of the endocardium where the procedure is to be
performed.
[0012] The delivery catheter of the invention may be advanced
through a previously introduced guiding catheter which has a lumen
in fluid communication with a port in the distal end of the
catheter. In accordance with one aspect of the invention, the
guiding catheter of the invention itself has a flexible
intermediate shaft section between less flexible proximal and
distal shaft sections, in the same or similar manner as the
delivery catheter. The discussion above relating to the relative
flexibility and length of the proximal, intermediate, and distal
sections on the delivery catheter applies equally well for the
corresponding sections on the guiding catheter of the invention.
Whether the guiding catheter is advanced until its distal end is
disposed within the left ventricle or at least within the ascending
aortic passageway downstream of the left ventricle, the flexible
shaft section is sized and positioned on the catheter to occupy a
significant portion of the aortic arch. A nontraumatic distal tip
may be provided on the guiding catheter in a conventional
manner.
[0013] In one presently preferred method of practicing the
invention, the delivery catheter is percutaneously introduced into
a patient's peripheral artery, such as the femoral artery, and
advanced through the patient's arterial system until the distal end
is disposed within the patient's left ventricle or slightly
downstream of the aortic valve in the ascending aorta. The delivery
catheter may be advanced over a guidewire or within a guiding
catheter previously introduced which has a distal extremity
positioned within the left ventricle or within the ascending aorta
slightly downstream of the aortic valve. When myocardial
revascularization is to be performed, an intravascular device
having a means to form channels in the patient's heart wall is
advanced through the lumen of a properly positioned delivery
catheter until the operative end of the device is positioned at a
desired location within the patients heart. The position of the
delivery catheter and the intravascular device may be adjusted to
precisely access a desired region of the endocardium.
[0014] Providing a flexible intermediate shaft section on a
catheter between the stiffer proximal and distal shaft sections of
the catheter facilitates passage of the catheter through the aortic
passageway. Catheter designs without this flexible section will
have difficulty advancing through the aortic arch, and will likely
contact the aortic wall. The result of the contact with the aortic
wall can be trauma to the wall and frictional drag on the catheter
hindering its maneuverability. Catheter designs with flexibility in
the distal region that is uniform or ever increasing towards the
distal tip fail to provide the torque control and kink resistance
inherent in the design of the invention. Moreover, when contact
with the heart wall does result, catheters having a flexible
intermediate shaft section will produce lower point loads against
the wall than would be produced by conventional catheters.
[0015] The flexible intermediate shaft section reduces the combined
system stiffness of a delivery catheter within a guiding catheter.
This, along with a reduction in the pushing force produced from
contact of the catheter distal end with the heart wall, lowers the
force against the heart wall and the drag on rotation of the
catheter. Unlike the catheter of the invention, conventional
catheters in contact with a heart wall produce a significant
pushing force against the heart wall which restricts the freedom of
rotation of the catheter. These and other advantages of the
invention will becom more apparent from the following detailed
description of the invention and the accompanying exemplary
drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0016] FIG. 1 is an elevational view, partially in section, of a
delivery catheter which embodies features of the invention with a
revascularization device therein.
[0017] FIG. 2 is an elevational view, partially in section, of a
guiding catheter which embodies features of the invention.
[0018] FIG. 3 illustrates the positioning of the assembly of an
embodiment of the invention within the patient's left ventricle and
aortic arch with the distal extremity of the guiding catheter
within the ascending aortic passageway and the distal extremity of
the delivery catheter within the left ventricle and a
revascularization device positioned against a patient's heart wall.
The flexible intermediate section of the guiding catheter is shown
disposed in the aortic arch.
[0019] FIG. 4 illustrates the position of the assembly similar to
that shown in FIG. 3 except that the guiding catheter extends
within the left ventricle and the distal extremity of the delivery
catheter system is disposed more centrally within the left
ventricle.
[0020] FIG. 5 illustrates the position of the assembly similar to
that shown in FIG. 3 except that a guiding catheter is not present.
The flexible intermediate shaft section of the delivery catheter is
shown disposed in the aortic arch.
DETAILED DESCRIPTION OF THE INVENTION
[0021] As shown in FIG. 1, the delivery catheter 10 of the
invention generally includes an elongated shaft 11, a proximal
shaft section 13, an intermediate shaft section 14, and a distal
shaft section 15. The distal shaft section 15 has a distal end 16
with a port 17 in fluid communication with a lumen 18 extending
through the catheter shaft 11. A therapeutic or diagnostic device
19, such as an ultrasonic, laser, or electrode based device for
tissue ablation or sensing, is slidably disposed within the lumen
18 of the delivery catheter 10. In FIG. 1 the therapeutic device 19
illustrated is a revascularization device, such as described in
copending application Ser. No. 08/584,957 (M. A. Javier, Jr. et
al.) filed on Jan. 11, 1996, which is incorporated herein by
reference.
[0022] FIG. 2 illustrates a guiding catheter 20 embodying features
of the invention which generally includes an elongated shaft 21, a
proximal shaft section 23, art intermediate shaft section 24, and a
distal shaft section 25. The distal shaft section 25 has a distal
end 26 which includes a nontraumatic distal tip 29. A port 27 is
provided on the distal tip 29, which is in fluid communication with
a lumen 28 extending through the catheter shaft 21. The lumen 28 is
configured to slidably receive the delivery catheter 10 and
therapeutic or diagnostic device 19 therein.
[0023] FIGS. 1 and 2 illustrate presently preferred embodiments of
the delivery and guiding catheter in which the distal shaft
sections, 15 and 25 respectively, are bent at an angle, .phi. and
.phi.' respectively. However, the distal extremity of the delivery
and guiding catheters of the invention may contain a variety of
shapes conventional in catheter design.
[0024] FIGS. 3 and 4 illustrate the placement of the catheter
system of the invention within the patient, with the delivery
catheter 10 slidingly disposed within the lumen 28 of the guiding
catheter 20 and the therapeutic device 19 extending into the
patient's left ventricle 40. In FIG. 3, the guiding catheter 20 is
shown within the patient's ascending aorta 41. The guiding catheter
20 is positioned so that the intermediate shaft section 24 occupies
the aortic arch 42, and the guiding catheter distal end 26 is
within the ascending aorta 41 downstream of the left ventricle 40
and aortic valve 43. FIG. 4 illustrates the guiding catheter 20
extending into the left ventricle 40. Although the guiding catheter
20 may be advanced into the left ventricle 40 as shown in FIG. 4,
the intermediate shaft section 24 is sized so that it still
occupies a significant portion of the aortic arch 42 (not
shown).
[0025] In FIG. 5, the delivery catheter 10 shown in FIG. 3 is
illustrated without a guiding catheter 20, and is positioned so
that the intermediate shaft section 14 occupies the aortic arch
42.
[0026] FIGS. 3 and 5 illustrate presently preferred embodiments of
the guiding catheter and delivery catheter, respectively, in which
the length of the distal shaft sections 25 and 15 is relatively
small compared to the length of the intermediate shaft sections 24
and 14 respectively. The overall length of the delivery catheter 10
is typically 5 cm to about 30 cm longer than the guiding catheter
to ensure that the proximal end 13 and distal end 15 of the
delivery catheter extend out the guiding catheter 20 proximal end
23 and distal end 25 respectively, to control the direction and
location of the distal end of the delivery catheter by manipulation
of the proximal end of the delivery catheter from outside of the
patient's body.
[0027] The delivery catheter 10 and guiding catheter 20
intermediate shaft sections 14 and 24 are constructed to be
relatively flexible compared to the proximal and distal shaft
sections, to facilitate advancement of the catheters through the
ascending aorta 41. The proximal and distal shaft sections have
stiffnesses of about 2, preferably about 3 times that of the
flexible intermediate shaft section. A method of measuring the
desired stiffness which has been found suitable is a modification
of ASTM test D747. This modification measures the load required to
deflect a cantilevered specimen 12.7 mm from the fixed end a
distance of 1 mm. For the intermediate shaft section of the
delivery catheter, a suitable load is about 5 to about 30 gms,
preferably about 10 to 20 gms. For the proximal and distal stiff
shaft sections, the loads should range about 20 to 70 gm,
preferably about 30 to 50 gms. Guiding catheters are generally
stiffer than the delivery catheters and the load ranges about 60 to
about 200 gms, preferably about 100 to 150 gms for the proximal and
distal shaft sections, and about 30 to 100 gms preferably about 50
to 80 gms for the flexible intermediate shaft sections. In a
presently preferred embodiment, the load values of the proximal and
distal shaft sections of a catheter are substantially similar.
However, it may be desirable to have a proximal shaft section with
a higher load value, i;e., greater stiffness, than the distal shaft
section. The various catheter shaft sections may be formed of
conventional materials providing the desired flexibility and
strength characteristics. For example, the delivery catheter 10
intermediate shaft section 14 may be a relatively flexible material
such as PEBAX 55D, and the proximal and distal shaft section may be
a high strength, stiff material such as PEBAX 72D or nylon, and is
preferably PEBAX 72D. The wall thickness of the intermediate shaft
section may be about 0.050 mm to about 0.20 mm less than the wall
thickness of the proximal and distal shaft sections to provide an
intermediate shaft section with the desired flexibility relative to
the other shaft sections.
[0028] In a presently preferred method of the invention, the
guiding catheter 20 is first introduced into the patient's arterial
system and advanced through the system until the distal end 26 is
disposed at the desired location either within the ascending aorta
41 downstream of the left ventricle 40 or within the left ventricle
40. When the guiding catheter 20 is in place, the intermediate
shaft section 24 will occupy a significant portion of the aortic
arch. The delivery catheter 10 and therapeutic or diagnostic device
19 may then be advanced together or sequentially through the
guiding catheter 10 into the left ventricle 40, at which point
intermediate shaft section 14 occupies the aortic arch 42 as well.
The delivery catheter 10 may be rotated, or advanced and retracted
to position the distal end at the desired region of the
endocardium. The diagnostic or therapeutic device 19 may then be
advanced out the port 17 in the distal end 16 of catheter to a
point adjacent to the endocardium of the patient's heart. After the
procedure the device may be withdrawn or repositioned within the
left ventricle 40. FIG. 5 illustrates an alternative method of
practicing the invention in which the delivery catheter 10 has been
advanced through the patient's arterial system to the ascending
aorta 41 without the aid of a guiding catheter, possibly using a
guidewire (not shown).
[0029] While the present invention is described herein in terms of
certain preferred embodiments, those skilled in the art will
recognize that various modifications and improvements may be made
to the invention without departing from the scope thereof.
* * * * *