U.S. patent application number 10/741574 was filed with the patent office on 2004-07-08 for balloon catheter with distal guide wire lumen.
This patent application is currently assigned to SCIMED LIFE SYSTEMS, INC.. Invention is credited to Euteneuer, Charles L., Keith, Peter T..
Application Number | 20040133158 10/741574 |
Document ID | / |
Family ID | 27076342 |
Filed Date | 2004-07-08 |
United States Patent
Application |
20040133158 |
Kind Code |
A1 |
Keith, Peter T. ; et
al. |
July 8, 2004 |
Balloon catheter with distal guide wire lumen
Abstract
An over-the-wire balloon dilatation catheter has a stainless
steel hypotube catheter shaft, an intermediate sleeve section
bonded to the shaft and a distal balloon section connected to the
sleeve section. The sleeve section is formed from relatively
flexible polymer materials and includes an inner core tube which
defines a guide wire lumen extending only through a distal portion
of the catheter (including its sleeve and balloon sections) to
facilitate fast balloon catheter exchanges. A distal end of the
hypotube shaft is crimped laterally and the core tube is nested and
bonded within the crimp to provide a proximal outlet for the guide
wire lumen. The hypotube shaft provides an inflation lumen for the
balloon, with the inflation lumen being continued as an annular
inflation lumen through the sleeve section where an outer sleeve is
bonded about the core tube and extends from the distal end of the
hypotube shaft to the balloon section. A kink-resistant coil
structure extends distally from the distal end of the hypotube
shaft to provide a gradual change in stiffness along the length of
the catheter from the relatively stiff hypotube shaft to the
relatively flexible distal portion of the catheter.
Inventors: |
Keith, Peter T.; (Fridlev,
MN) ; Euteneuer, Charles L.; (St. Michael,
MN) |
Correspondence
Address: |
Glenn M. Seager
CROMPTON, SEAGER & TUFTE, LLC
Suite 800
1221 Nicollet Avenue
Minneapolis
MN
55403-2420
US
|
Assignee: |
SCIMED LIFE SYSTEMS, INC.
|
Family ID: |
27076342 |
Appl. No.: |
10/741574 |
Filed: |
December 19, 2003 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10741574 |
Dec 19, 2003 |
|
|
|
09886328 |
Jun 21, 2001 |
|
|
|
6733487 |
|
|
|
|
09886328 |
Jun 21, 2001 |
|
|
|
09132119 |
Aug 11, 1998 |
|
|
|
6273879 |
|
|
|
|
09132119 |
Aug 11, 1998 |
|
|
|
08955049 |
Oct 21, 1997 |
|
|
|
08955049 |
Oct 21, 1997 |
|
|
|
08657013 |
May 30, 1996 |
|
|
|
5702439 |
|
|
|
|
08657013 |
May 30, 1996 |
|
|
|
08521460 |
Aug 30, 1995 |
|
|
|
5522818 |
|
|
|
|
08521460 |
Aug 30, 1995 |
|
|
|
08344931 |
Nov 23, 1994 |
|
|
|
08344931 |
Nov 23, 1994 |
|
|
|
08035254 |
Mar 22, 1993 |
|
|
|
5395334 |
|
|
|
|
08035254 |
Mar 22, 1993 |
|
|
|
07792786 |
Nov 15, 1991 |
|
|
|
5217482 |
|
|
|
|
07792786 |
Nov 15, 1991 |
|
|
|
07574265 |
Aug 28, 1990 |
|
|
|
5156594 |
|
|
|
|
Current U.S.
Class: |
604/103.04 |
Current CPC
Class: |
A61M 25/104 20130101;
A61M 25/0029 20130101; A61M 25/0054 20130101; A61M 2025/0098
20130101; A61M 25/0032 20130101; A61M 2025/1079 20130101; A61M
2025/0034 20130101; A61M 2025/0079 20130101; A61M 2025/1061
20130101; A61M 25/0662 20130101; A61M 2025/09191 20130101; A61M
2025/1056 20130101; A61M 2025/0183 20130101 |
Class at
Publication: |
604/103.04 |
International
Class: |
A61M 029/00 |
Claims
What is claimed is:
1. A balloon dilatation catheter comprising: a tube formed from a
relatively stiff material composition, the tube defining a first
shaft section having a proximal end and a distal end; a second
shaft section, more flexible than the first shaft section, disposed
distally of the first shaft section; the first and second shaft
sections having an inflation lumen defined therethrough; a
dilatation balloon attached to the distal end of the second shaft
section, the dilatation balloon being in fluid communication with
the inflation lumen such that inflation pressure may be provided to
the balloon therethrough; an intermediate section disposed between
the first shaft section and the second shaft section, the
intermediate section configured to include a stiffness between the
stiffness of the first shaft section and the stiffness of the
second shaft section; and wherein the second shaft section includes
a second lumen extending through the interior of the balloon, the
second lumen being shorter than the inflation lumen, the second
lumen having a proximal guide wire opening at its proximal end and
a distal guide wire opening at its distal end, and the second lumen
being formed and aligned to receive a guide wire there in such that
the catheter may be slidably moved on the guide wire.
2. The balloon dilatation catheter of claim 1 wherein the proximal
guide wire opening is disposed adjacent the proximal end of the
second shaft section.
3. The balloon dilatation catheter of claim 1 wherein the proximal
guide wire opening is disposed adjacent the distal end of the first
shaft section.
4. The balloon dilatation catheter of claim 1 wherein the proximal,
guide wire opening is disposed along the intermediate section.
5. The balloon dilatation catheter of claim 1 wherein the
intermediate section has a portion of relatively constant stiffness
therealong.
6. The balloon dilatation catheter of claim 1 wherein the
intermediate section includes a metallic member adjacent the
proximal guide wire lumen opening.
7. The balloon dilatation catheter of claim 6 wherein the metallic
member has a relatively uniform metallic dimension therealong.
8. The balloon dilatation catheter of claim 6 wherein the metallic
member is located at least in part around the inflation lumen.
9. The balloon dilatation catheter of claim 6 wherein the metallic
member comprises a coil.
10. The balloon dilatation catheter of claim 6 wherein the metallic
member has a distal terminal end spaced proximally from the
balloon.
11. The balloon dilatation catheter of claim 1 wherein at least a
portion of the intermediate section is offset axially relative to
the first and second shaft sections.
12. The balloon dilatation catheter of claim 11 wherein the
proximal guide wire lumen opening is disposed along that portion of
the intermediate section which is offset axially relative to the
first and second shaft sections.
13. The balloon catheter of claim 1 wherein the tube is formed from
a metallic material.
14. In an elongate dilatation catheter of the type that can be
slidably moved along a guide wire that can extend past a distal end
of the catheter, wherein the guide wire is received in a guide wire
lumen of the catheter, the guide wire extending from a distal guide
wire lumen opening to a proximal guide wire lumen opening disposed
in a portion of the catheter that is spaced distally from a
proximal end of the catheter, the dilatation catheter including an
inflatable balloon and an inflation lumen extending through the
catheter separate from the guide wire lumen, an improvement
comprising: a tube formed from a relatively stiff material
composition, the tube defining a first shaft section having a
proximal end and a distal end; a second shaft section disposed
distally of the first shaft section, the second shaft section being
relatively more flexible than the first shaft section and having
the guide wire lumen extending through a portion thereof; and an
intermediate section disposed between the first shaft section and
the second shaft section, the intermediate section including an
intermediate member adjacent the proximal guide wire lumen opening
which is of diminished dimension relative to the tube such that at
least a portion of the intermediate section is more flexible than
the first shaft section and less flexible than the second shaft
section.
15. The improved catheter of claim 14 wherein the tube is formed
from a metallic material.
16. The improved catheter of claim 14 wherein the intermediate
metallic member has a relatively uniform metallic dimension
therealong.
17. The improved catheter of claim 14 wherein the intermediate
metallic member is located at least in part around the inflation
lumen.
18. The improved catheter of claim 14 wherein the intermediate
metallic member comprises a coil.
19. The improved catheter of claim 14 wherein the intermediate
section extends at least in part across the proximal guide wire
lumen opening.
20. The improved catheter of claim 14 wherein the proximal guide
wire lumen opening is disposed adjacent the proximal end of the
second shaft section.
21. The improved catheter of claim 14 wherein the proximal guide
wire lumen opening is disposed adjacent the distal end of the first
shaft section.
22. The improved catheter of claim 14 wherein the proximal guide
wire opening is disposed along the intermediate section.
23. The improved catheter of claim 14 wherein at least a portion of
the intermediate section is adopted to impart a stepped transition
in flexibility between the first shaft section and the second shaft
section.
24. The improved catheter of claim 14 wherein at least a portion of
the intermediate section is offset axially relative to the first
and second shaft sections.
25. The improved catheter of claim 14 wherein the proximal guide
wire lumen opening is disposed along that portion of the
intermediate section which is offset axially relative to the first
and second shaft sections.
26. In an elongate dilatation catheter which has an inflatable
balloon and a inflation lumen extending through the catheter,
wherein the catheter is of the type that can be slidably roved
along a guide wire that can extend past a distal end of the
catheter through a guide wire lumen of the catheter, wherein the
guide wire lumen is separate from the inflation lumen and extends
from a distal guide wire lumen opening to a proximal guide wire
lumen opening located in a portion of the catheter that is spaced
distally from a proximal end of the catheter so that the guide wire
lumen is shorter than the inflation lumen, an improvement
comprising: a first proximal shaft section of the catheter defined
by a tubing of relatively rigid material; a second shaft section
disposed distally of the first shaft section, the second shaft
section being relatively more flexible than the first shaft
section; and a transition section disposed between the first shaft
section and the second shaft section and including a metallic
element of diminished dimension relative to the tubing, the
transition section extending adjacent to the proximal guide wire
lumen opening and having an intermediate rigidity to provide a
stepped transition between the first shaft section and the second
shaft section.
27. The improved catheter of claim 26 in which the tubing is formed
from a metallic material.
28. The improved catheter of claim 26 in which the metallic element
extends at least in part distally of the proximal guide wire lumen
opening.
29. The improved catheter of claim 26 in which the metallic element
extends at least in part around the inflation lumen.
30. The improved catheter of claim 26 in which the metallic element
comprises a coil.
31. The improved catheter of claim 26 in which the metallic element
has a distal terminal end spaced proximally from the balloon.
32. The improved catheter, of claim 26 in which the proximal guide
wire lumen opening is disposed adjacent the proximal end of the
second shaft section.
33. The improved catheter of claim 26 in which the proximal guide
wire lumen opening is disposed adjacent the distal end of the first
shaft section.
34. In an elongate dilatation catheter which has an inflatable
balloon and an inflation lumen extending through the catheter,
wherein the catheter is of the type that can be slidably moved
along a guide wire which can extend past a distal end of the
catheter through a guide wire lumen of the catheter, wherein the
guide wire lumen is separate from the inflation lumen and extends
from a distal guide wire lumen opening to a proximal guide wire
lumen opening disposed in a portion of the catheter that is spaced
distally from a proximal end of the catheter so that the guide wire
lumen is shorter than the inflation lumen, an improvement
comprising: a first proximal shaft section of the catheter defined
by a tubing of relatively rigid material; a second shaft section
disposed distally of the first shaft section, the second shaft
section being relatively more flexible than the first shaft
section; and a transition section disposed between the first shaft
section and the second shaft section and extending adjacent to the
proximal guide wire lumen opening, the transition section having
decreased rigidity relative to the tubing to provide a stepped
transition in flexibility between the first shaft section and the
second shaft section.
35. The improved catheter of claim 34 in which the tubing is formed
from a metallic material.
36. The improved catheter of claim 34 in which the transition
section extends at least in part distally of the proximal guide
wire lumen opening.
37. The improved catheter of claim 34 in which the transition
section extends at least in part around the inflation lumen.
38. The improved catheter of claim 34 in which the transition
section comprises a coil.
39. The improved catheter of claim 34 in which the transition
section is metallic and of reduced dimension relative to the
metallic tube.
40. The improved catheter of claim 34 in which the transition
section has a distal terminal end spaced proximally from the
balloon.
41. The improved catheter of claim 34 in which the proximal guide
wire lumen opening is disposed adjacent the proximal end of the
second shaft section.
42. The improved catheter of claim 34 in which the proximal guide
wire lumen opening is disposed adjacent the distal end of the first
shaft section.
43. In an elongate dilatation catheter of the type that has a
relatively long proximal shaft section, a second shorter distal
shaft section disposed distally of the first shaft section, an
inflatable balloon attached to the distal end of the second shaft
section wherein the first and second shaft sections have an
inflation lumen defined therethrough so that the balloon is in
fluid communication with the inflation lumen, and wherein the
catheter is of the type that can be slidably moved along a guide
wire which can extend through a guide wire lumen of the catheter,
the guide wire lumen being separate from the inflation lumen and
extending from a distal guide wire lumen opening at the distal end
of the catheter to a proximal guide wire lumen opening adjacent the
proximal end of the second shaft section so that the guide wire
lumen is shorter than the inflation lumen, an improvement
comprising: the first proximal shaft section of the catheter
defined by a tubing of relatively rigid material; the second shaft
section of the catheter being relatively more flexible than the
first shaft section and having a relatively short reinforced
proximal portion and a relatively long nonreinforced distal
portion; and the reinforced proximal portion including a transition
member disposed adjacent to the proximal guide wire lumen opening
and extending distally along the second shaft section to provide a
reinforcement therefore the transition member including a metallic
element having a uniform reduced dimension relative to the tubing
as it extends distally along the catheter to provide a stepped
transition in rigidity in the distal direction, the transition
member having a distal terminal end spaced from the balloon by the
length of the nonreinforced distal portion of the second shaft
section.
44. The improved catheter of claim 43 in which the tubing is formed
from a metallic member.
45. The improved catheter of claim 43 in which the transition
member extends at least in part distally of the proximal guide wire
lumen opening.
46. The improved catheter of claim 43 in which the transition
member extends at least in part around the inflation lumen.
47. The improved catheter of claim 43 in which the transition
member comprises a coil.
48. The improved catheter of claim 43 in which the proximal guide
wire lumen opening is disposed adjacent the distal end of the first
shaft section.
Description
RELATED APPLICATIONS
[0001] This is a Continuation Application of pending prior
application Ser. No. 07/792,786, filed on Nov. 15, 1991, which is a
Continuation of prior application Ser. No. 07/574,265, filed on
Aug. 28, 1990, which issued as U.S. Pat. No. 5,16,594, on Oct. 20,
1992.
BACKGROUND OF INVENTION
[0002] The present invention relates to the field of angioplasty.
In particular, the present invention relates to a dilatation
balloon catheter of the "over-the-wire" type having a relatively
short distal guide wire lumen extending through the balloon of the
catheter.
[0003] Angioplasty procedures have gained wide acceptance in recent
years as efficient and effective methods for treating types of
vascular disease. In particular, angioplasty is widely used for
opening stenoses in the coronary arteries, although it is also used
for the treatment of stenoses in other parts of the vascular
system.
[0004] The most widely used form of angioplasty makes use of a
dilatation catheter which has an inflatable balloon at its distal
end. Typically, a hollow guide catheter is used in guiding the
dilatation catheter through the vascular system to a position near
the stenoses (e.g., to the coronary artery ostia). Using
fluoroscopy, the physician guides the dilatation catheter the
remaining distance through the vascular system until a balloon is
positioned to cross the stenoses. The balloon is then inflated by
supplying fluid under pressure through an inflation lumen in the
catheter to the balloon. The inflation of the balloon causes
stretching of the artery and pressing of the lesion into the artery
wall, to reestablish acceptable blood flow through the artery.
[0005] There has been a continuing effort to reduce the profile and
shaft size of the dilatation catheter so that the catheter not only
can reach but also can cross a very tight stenosis. A successful
dilatation catheter must also be sufficiently flexible to pass
through tight curvatures, especially in the coronary arteries. A
further requirement of a successful dilatation catheter is its
"pushability". This involves the transmission of longitudinal
forces along the catheter from its proximal end to its distal end,
so that a physician can push the catheter through the vascular
system and the stenoses.
[0006] Two commonly used types of dilatation catheters are referred
to as "over-the-wire" catheters and "non-over-the-wire" catheters.
An over-the-wire catheter is one in which a separate guide wire
lumen is provided in the catheter so that a guide wire can be used
to establish the path through the stenoses. The dilatation catheter
can then be advanced over the guide wire until the balloon on the
catheter is positioned within the stenoses. One problem with the
over-the-wire catheter is the requirement of a larger profile and a
generally larger outer diameter along the entire length of the
catheter in order to allow for a separate guide wire lumen
therethrough.
[0007] A non-over-wire catheter acts as its own guide wire, and
thus there is no need for a separate guide wire lumen. One
advantage of a non-over-the-wire catheter is its potential for a
reduced outer diameter along its main shaft since no discrete guide
wire lumen is required. However, one disadvantage is the inability
to maintain the position of the guide wire within the vascular
system when removing the catheter and exchanging it for a catheter
having a smaller (or larger) balloon diameter. Thus, to accomplish
an exchange with a non-over-the-wire catheter, the path to the
stenoses rust be reestablished when replacing the catheter with one
having a different balloon diameter.
[0008] In an effort to combine the advantages of an over-the-wire
catheter with a non-over-the-wire catheter, catheters have been
developed which have guide wire lumens which extend from a distal
end of the catheter through the dilatation balloon and then exit
the catheter at a point proximal of the dilatation balloon. The
guide wire thus does not extend through the entire length of the
catheter and no separate guide wire lumen is required along a
substantially proximal section of the catheter. That proximal
section can thus have a smaller outer diameter since it is only
necessary to provide an inflation lumen therethrough for catheter
operation. A further advantage of this type of modified
over-the-wire-catheter is that the frictional forces involved
between the guide wire and the shortened guide wire lumen are
reduced, thereby reducing resistance to catheter pushability and
enhancing the "feel" and responsiveness of the catheter to a
physician.
[0009] Perhaps the most significant advantage of using a shortened
guide wire lumen is in the ease of exchange of the catheter over
the guide wire. In performing an angioplasty procedure using such a
catheter, the catheter is "back loaded" over the guide wire by
inserting the proximal tip of the guide wire into a distal opening
of the guide wire lumen in the catheter. The catheter is then
advanced by "feeding" the catheter distally over the guide wire
while holding the guide wire stationary. The proximal end of the
guide wire will then emerge out of the proximal opening of the
guide wire lumen (which is substantially spaced distally from the
proximal end of the catheter itself) and is accessible again for
gripping by the physician. The catheter can be preloaded onto the
guide wire in this manner before the guide wire is inserted into
the guide catheter or after. The either case, the guide wire is
steered and passed through the guide catheter, coronary vessels and
across a lesion. The exposed portion of the guide wire is then
grasped while the catheter is advanced distally along the guide
wire across the lesion. Using this procedure, little axial movement
of the guide wire occurs during catheter loading and positioning
for angioplasty.
[0010] If the dilatation balloon is found to be inadequate (too
small or too large), the catheter can be similarly withdrawn
without removing the guide wire from across the lesion. The guide
wire is grasped while the catheter is withdrawn, and when the
proximal opening of the guide wire lumen is reached, the grasping
hand must be moved incrementally away from the proximal opening as
the catheter is incrementally withdrawn, until the catheter is
fully removed from the guide catheter and the guide wire is thus
again exposed and accessible adjacent to the proximal end of the
guide catheter.
[0011] This shortened guide wire lumen type of dilatation catheter
design thus offers the advantages associated with the rapid
exchangeability of catheters. The design also presents the
potential to provide a smaller catheter shaft, since the guide wire
is not contained within the proximal portion of the catheter shaft.
The smaller catheter shaft thus allows for better contrast media
injection and, as a result, better visualization. In addition,
because of the rapid exchangeability features, standard
non-extendable guide wires of approximately 175 centimeters in
length may be used. Further, because the guide wire is contained in
only a distal shorter guide wire lumen of the catheter, free wire
movement is enhanced when compared to a standard over-the-wire
catheter where the guide wire extends through a guide wire lumen
extending along the entire length of the catheter.
[0012] While several structures for such shortened guide wire lumen
dilatation catheter have been proposed these structures suffer from
several disadvantages. Such catheters have been one piece
polyethylene catheters having dual lumen configurations adjacent
their distal regions. Typically, such catheters have larger than
necessary shaft sizes and are stiffer in their distal regions than
would be desired, including those portions bearing the dilatation
balloon. A further disadvantage is that the proximal shaft portion
of such catheters is relatively flexible, and has low column
strength shaft, so that it tends to "bunch" and buckle when
advanced across a lesion. To counteract this deficiency in such
designs, additional stiffener elements have been provided in the
shaft, which necessarily require a larger catheter shaft to
accommodate the stiffener element structure. The known dilatation
balloon catheter designs which include shortened guide wire lumens
extending through the distal portion of the catheter suffer from
the disadvantages mentioned above and do not take advantage of the
unique opportunities presented by the possibilities of such designs
in construction and application.
SUMMARY OF THE INVENTION
[0013] The present invention is an over-the-wire dilatation balloon
catheter which has a guide wire lumen extending through only a
distal portion of the catheter. The guide wire lumen extends from a
distal end of the catheter proximally through a balloon of the
catheter and exits the catheter at a point proximal of the balloon,
but substantially distally from a proximal end of the catheter
itself.
[0014] The present invention for a balloon dilatation catheter
includes a thin-walled, high strength metallic tube having a
longitudinal inflation lumen extending therethrough from its
proximal end to its distal end. An intermediate sleeve section
extends distally from the metallic tube. The sleeve section is more
flexible than the metallic tube, and includes a proximal segment of
inner core tube which has a longitudinal guide wire lumen extending
therethrough and an outer sleeve which extends over the proximal
segment of the core tube to define a longitudinally extending
annular inflation lumen therebetween that is in fluid communication
with the inflation lumen of the metallic tube. The guide wire lumen
has an outlet at a proximal end of the proximal segment of the core
tube, and the core tube has a distal segment which extends distally
beyond the distal end of the outer sleeve. Means are provided for
exposing the guide wire lumen outlet to the exterior of the
catheter adjacent and proximal to the distal end of the metallic
tube, without compromising the integrity of the inflation lumens
extending through the catheter. An inflatable balloon extends over
the distal segment of the core tube and has its proximal end
connected to the distal end of the outer sleeve. A distal end of
the balloon is connected to the core tube so that an interior of
the balloon is in fluid communication with the annular inflation
lumen in the sleeve section. Means are provided for preventing
significant closure of the guide wire lumen and annular inflation
lumen in the sleeve section adjacent the distal end of the metallic
tube when the more flexible sleeve section is bent laterally
relative to the metallic tube.
[0015] In a preferred embodiment of the present invention, the
metallic tube is formed from a proximal relatively long stainless
steel tube and a distal relatively short stainless steel tube
bonded thereto. The outer diameter of the proximal tube is smaller
than the outer diameter of the distal tube, thus providing a
catheter structure which is highly trackable and has a generally
all shaft cuter diameter, yet is very pushable and responsive to a
doctor controlling movement of the catheter from its proximal end.
Preferably, the means for exposing includes a longitudinal crimp
adjacent the distal end of the distal stainless steel tube. The
crimp extends laterally inwardly from one side of the distal tube,
and has a proximal transition region and distal bonding region. The
proximal end of the inner core tube is nested within the distal
bonding region of the crimp and bonded thereto. The outer sleeve
extends over at least a distal portion of the bonding region and is
sealably affixed thereabout.
[0016] The means for preventing closure of a present invention may
take a number of different forms. In a preferred embodiment, the
means for preventing closure comprises a coil member affixed to the
sleeve section adjacent the distal end of the metallic tube. As
such, the coil member may be affixed about the outer sleeve to
extend distally from the metallic tube or about the inner core tube
to extend distally from the metallic tube. Such a coil member
further nay have its coils spaced uniformly apart or spaced
increasingly apart as it extends distally from the metallic tube.
Preferably, the coil member is formed from a spirally shaded
ribbon. A compression sheath is provided to envelope the coil
member and maintain the coil member in secure engagement to the
sleeve section. In an alternative embodiment, the means for
preventing closure comprises a tubular member affixed to the sleeve
section adjacent the distal end of the metallic tube, with the
tubular member being formed from a polyimide material.
[0017] Such closure preventing means thus provide a bending relief
design between the relatively stiff metallic tube and more flexible
distal region of the balloon dilatation catheter, to prevent
kinking during catheter preparation work and handling (prior to
insertion of the dilatation catheter into the guide catheter and
patient). Such kinking or "crimping" of the catheter can result in
a binding on the guide wire as it extends through the guide wire
lumen or a reduction in size of the annular inflation lumen between
the metallic tube and balloon or a compromise in strength of the
catheter tubings, all of which will compromise the utility and
responsiveness of the dilatation catheter. In addition, the closure
preventing means reduces the possibility of a failure or separation
of the bonds adjacent the distal end of the metallic tube which may
be caused by excess strain placed on such bonds during catheter
preparation or handling.
BRIEF DESCRIPTION OF THE DRAWINGS
[0018] FIG. 1 is a side elevational view of a balloon dilatation
catheter of the present invention having a distal guide wire lumen
therethrough and showing a guide wire.
[0019] FIG. 2 is a sectional side elevational view of the balloon
dilatation catheter of FIG. 1.
[0020] FIG. 3 is an enlarged sectional view as taken along lines
3-3 in FIG. 2.
[0021] FIG. 4 is a sectional side elevational view of a portion of
the catheter of the present invention, illustrating an alternative
structure for a reinforcing coil member thereon.
[0022] FIG. 5 is a sectional side elevational view of a portion of
the catheter of the present invention, illustrating an alternative
structure for a reinforcing coil member thereon.
[0023] FIG. 6 is an enlarged sectional view as taken along lines
6-6 in FIG. 5.
[0024] FIG. 7 is a sectional view of a portion of an alternative
embodiment of the catheter of the present invention.
[0025] FIG. 8 is a sectional view of a portion of an alternative
embodiment of the catheter of the present invention.
[0026] FIG. 9 is a sectional view of a portion of an alternative
embodiment of the catheter of the present invention.
[0027] FIG. 10 is a sectional view of a portion of an alternative
embodiment of the catheter of the present invention.
[0028] FIG. 11 is a sectional view of a portion of an alternative
embodiment of the catheter of the present invention.
[0029] FIG. 12 is a sectional view of a portion of an alternative
embodiment of the catheter of the present invention.
[0030] FIG. 13 is a sectional view of a portion of an alternative
embodiment of the catheter of the present invention.
[0031] Although the above-identified drawing figures set forth
various embodiments of the invention, other embodiments of the
invention are also contemplated, as noted in the discussion. In all
cases, this disclosure presents illustrated embodiments of the
present invention by way of representation and not limitation. It
should be understood that numerous other modifications and
embodiments can be devised by those skilled in the art which will
fall within the scope and spirit of the principles of this
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Overall Catheter Structure
[0032] A balloon dilatation catheter 20 of the present invention is
illustrated generally in FIG. 1. The catheter 20 has a proximal
main shaft section 22, an intermediate sleeve section 24 and a
distal balloon section 26. The main shaft section 22 has a proximal
end 28 and a distal end 30. Likewise, the intermediate sleeve
section 24 has a proximal end 32 and a distal end 34. The distal
balloon section 26 has a proximal waist 36, an intermediate
expandable segment 38 and a distal waist 40.
[0033] As illustrated in FIG. 1, the distal end 30 of the main
shaft section 22 is connected to the proximal end 32 of the sleeve
section 24, and the distal end 34 of the sleeve section 24 is
connected to the proximal waist 36 of the balloon section 26. In
use, the catheter 20 is coupled to an inflation device (not shown)
by a luer manifold 42 connected to the proximal end 28 of the rain
shaft section 22. The inflation device thus provides or removes
inflation solution from the catheter 20 to selectably inflate or
deflate the intermediate expandable segment 38 of the distal
balloon section 26 (in FIG. 1, expandable segment 38 is shown in
its inflated configuration).
[0034] The catheter 20 of the present invention is designed for use
in combination with a catheter guide element such as a guide wire
50. In use in a coronary application, both the guide wire 50 and
the catheter 20 are fed through and guided to an arterial lesion by
means of a tabular guide catheter (not shown). Both the catheter 20
and guide wire 50 are therefore longer than the guide catheter,
with a typical catheter length of approximately 135 cm and a
typical guide wire length of approximately 175 cm. As illustrated
in FIG. 1, the guide wire 50 extends longitudinally along the
exterior of the main shaft section 22 of the catheter 20. Adjacent
the distal end 30 of the main shaft section 22, the guide wire 50
enters the structure of the catheter 20 and extends distally
therethrough until it exits the catheter structure adjacent the
distal waist 40 of the distal balloon segment 26. As seen FIG. 2, a
separate guide wire lumen 52 is provided in the catheter 20 through
the intermediate sleeve section 24 and distal balloon section 26
thereof. The guide wire 50 thus is only entrained within the
catheter 20 within this guide wire lumen 52, which is much shorter
than the total length of the catheter 20 (e.g., the guide wire
lumen 52 is approximately 30 cm long). The guide wire 50 has a
proximal end 53 and a distal end 54 and is of a typical structure
for guiding angioplasty catheters. At its distal end 54, the guide
wire 50 preferably has a coiled and rounded tip structure which is
bendable for steerability of the guide wire.
[0035] Referring now to FIG. 2, which shoes the catheter 20 in
greater detail, it is seen that the proximal end 28 of the rain
shaft section 22 further has a strain relief tube 60 disposed
between the luer manifold 42 and shaft section 22. The strain
relief tube 60 is larger than the main shaft section 22, and thus
provides a step-wise strain relief function between the inflexible
luer manifold 42 and the more flexible main shaft section 22. The
main shaft section 22, tubular member 60 and luer manifold 42 are
secured together respectively by suitable adhesive means, such as
epoxy or cyanoacrylate.
Main Shaft Section
[0036] The main shaft section 22 is preferably formed as a
thin-walled, high strength stainless steel tube structure, which is
referred to as hypodermic tubing or hypotube. As a tubular
structure the main shaft section 22 thus has a longitudinally
extending inflation lumen 62 extending therethrough from its
proximal end 28 to its distal end 30, which provides a means for
the movement and pressurization of inflation fluid through the
catheter 20 to and from the distal balloon section 26.
[0037] In a preferred embodiment, the main shaft section 22 is
formed from two stainless steel tube sections, a proximal
relatively long shaft section 64 and a distal relatively short
shaft section 66. A distal end of the proximal shaft section 64 and
a proximal end of the distal shaft section 66 are sealably affixed
together by suitable means, such as by a solder joint. The proximal
end of the distal shaft section 66 fits coaxially over the distal
end of the proximal shaft section 64, as seen in FIG. 2, thereby
allowing the proximal shaft section 64 to assume a smaller outer
diameter than the distal shaft section 66. The main shaft section
22 is provided with a lubricous coating (such as
polytetraflouroethylene) to lessen frictional resistance (at least
to the extent that the proximal shaft section 64 is so coated). The
use of a thin-walled (e.g., 0.003 inch wall thickness), metallic
tube structure for the main shaft section 22 thus provides a stiff
enough shaft for pushability yet allows for a relatively small
diameter shaft, thereby enhancing catheter visualization via
fluoroscopy and catheter versatility. The inherent high strength
nature of such a structure also allows it to withstand the fluid
pressures necessary for proper catheter operation, which in a
plastic shaft structure would require thicker walls. The high
column strength and thickness of a hypotube shaft also gives
improved responsiveness to the catheter. Thus, the balloon and
distal regions of the catheter move definitively (in a 1:1
relationship) with motions imparted at the catheter's proximal end
by a physician. This feature allows the physician to actually
"sense" the pathway as the catheter is tracked, which gives
valuable information in the passage of the catheter to and through
the lesion.
[0038] In the distal shaft section 66 of the main shaft section 22,
a longitudinal crimp 68 is provided which extends laterally
inwardly from one side of the distal section 66. The distal shaft
section 66 has three sections, a proximal tubular region 70, a
transition region 72, and a distal bonding region 74. The crimp 68
extends from its proximal origin in the transition region 72 to its
greatest lateral depth in the bonding region 74. The crimp 68, as
further illustrated in FIG. 3, does not seal off or close the
inflation lumen 62, but does transform the inflation lumen from, a
circular lumen 62 to a crescent shape through the bonding region
74, as seen at 63 in FIG. 3.
Catheter Intermediate Sleeve Section
[0039] The intermediate sleeve section 24 extends distally from the
main shalt section 22, and is bonded thereto adjacent the bonding
region 74 of the distal shaft section 66. The intermediate sleeve
section 24 has two primary longitudinal components, an inner core
tube 80 and an cuter sleeve or tube 82. The inner core tube 80 has
a proximal segment 84 within the sleeve section 24 and a distal
segment 86 within the distal balloon section 26. The inner core
tube 80 and outer sleeve 82 are both preferably formed from
thin-walled high density polyethylene.
[0040] The inner core tube 80 has a proximal end 88 and a distal
end 90. At its proximal end 88, the core tube 80 is nested within
the bonding region 74 of the distal shaft section 66 and bonded
thereto by suitable means, such as epoxy or cyanoacrylate. The core
tube 80 is thus affixed to the main shaft section 22 in an
"off-axis" alignment at the bonding region 74. However, as seen in
FIG. 2, as the core tube 80 extends distally from the main shaft
section 22, it is aligned generally coaxially with the shaft
section 22.
[0041] The core tube 80 defines the guide wire lumen 52 extending
through the catheter 20. The guide wire lumen thus has a proximal
outlet 92 adjacent the proximal end of the core tube 80 and a
distal cutlet 94 adjacent the distal end 80 of the core tube 80. At
least one marker band 96 is provided about the core tube 80
(preferably centered within the expandable segment 38 of the distal
balloon section 26) to aid in illuminating the position of the
catheter 20 via fluoroscopy during an angioplasty procedure.
[0042] The cuter sleeve 82 is generally tubular in form, and has a
proximal end 100 and a distal end 102. The outer sleeve 82 is
bonded about the distal shaft section 66 and the core tube 80
adjacent the bonding region 74, as seen in FIGS. 2 and 3 and is
held in place thereto by suitable means, such as epoxy or
cyanoacrylate. The outer sleeve 82 extends distally from the main
shaft section 22 over the proximal segment 84 of the core tube 80,
and as such, defines a distal continuation of the inflation lumen
of the catheter 20. A longitudinally extending annular inflation
lumen 104 is formed between the core tube 80 and outer sleeve 82.
Of course, the proximal end 100 of the outer sleeve 82 is securely
sealed about the distal shaft section 66 and the core tube 80 so
that the longitudinal inflation lumens 62 and 104 through the
catheter 20 are not compromised to the exterior of catheter 20, but
are in fluid communication therethrough.
[0043] The intermediate sleeve structure defined above is the basic
sleeve structure for all embodiments of the present invention
contemplated and disclosed herein--namely, an inner core tube
bonded to a distal portion of the main catheter shaft, with an
outer sleeve forming an annular continuation of the inflation lumen
through the main shaft between the core tube and outer sleeve. As
discussed below and illustrated herein, various configurations of
the connections and components relative to the formation of the
distal guide wire lumen, including the coupling of the main shaft
to the intermediate sleeve section, are contemplated.
Catheter Distal Balloon Section
[0044] The distal balloon section 26 is connected to the components
of the intermediate sleeve section 24. The proximal waist 36 of the
balloon section 26 is connected to the distal end 102 of the outer
sleeve 82 by suitable means, such as by epoxy or cyanoacrylate. The
distal waist 40 of the balloon section 26 is bonded to the core
tube 80 adjacent its distal end 90 by suitable means, such as by
epoxy or cyanoacrylate. An interior 106 of the balloon section 26
is thus sealed and in fluid communication with the annular
inflation lumen 104 within the sleeve section 24. In a preferred
embodiment, the balloon section 26 is forced from a compliant
balloon material (e.g., polyolefin), although a balloon formed from
thin-walled non-compliant material (e.g., PET--polyethylene
terephthalate) is also contemplated.
Kink-Resistant Structure
[0045] The metallic main shaft section 22 is relatively stiff
compared to the polyethylene intermediate sleeve section 24. This
creates a rather abrupt chance in the flexibility of the materials
for the catheter 20 adjacent the distal end 30 of the main shaft
section 22 (at the bonding region 74). The use of a hypotube for
the main shaft section 22 in the catheter 20 creates a catheter
which is considerably stiffer than most previous over-the-wire
angioplasty balloon catheter designs. Such stiffness is not a
concern as long as the metallic main shaft section 22 remains in
the relatively straight guide catheter within the patient, and
indeed such stiffness provides distinct benefits in use of the
catheter 20, as described above. In the distal portions of the
catheter 20 (intermediate sleeve section 24 and distal balloon
section 26), the catheter 20 must be very trackable and flexible in
order to negotiate the tortuous coronary anatomy to and across the
lesion. The relatively sharp transition in stiffness as the
catheter structure changes from the metallic main shaft section 22
to the much more flexible polymer intermediate sleeve section 24
creates two concerns. First, during handling of the catheter prior
to usage, there is a potential to kink the catheter structure at
that flexibility transition point. Secondly, when the catheter is
in vivo, the distal end 30 of the main shaft section 22 could
potentially "dig in" to the guide catheter and create excessive
friction due to the lack of bending support from a the more
flexible intermediate sleeve section 24.
[0046] To address these concerns, a kink-resistant structure 110 is
provided to prevent kinking and possible damage to the intermediate
sleeve section 24 during catheter preparation, handling and use. In
its simplest form, this kink-resistant structure 110 provides a
member of intermediate stiffness or transitory stiffness and
kink-resistant nature between the relatively stiff main shaft
section 22 and the relatively flexible intermediate sleeve section
24. The kink-resistant structure 110 includes a coil member 112
affixed to the intermediate sleeve section 24 adjacent the distal
end 30 of the main shaft section 22. The coil member 112 creates an
intermediate stiffener element between the relatively stiff main
shaft section 22 and the relatively flexible intermediate sleeve
section 24 to allow bending of the catheter without kinking. The
coil member 112 preferably has its coils spaced uniformly apart,
and is preferably formed from a spiral ribbon of stainless steel
placed about the outer sleeve 82 along that portion thereof
extending over the bonding region 74 and distally therefrom. The
coil member 112 is secured to the outer sleeve 82 by suitable
adhesive means, such as by epoxy. To further secure the coil member
112 to the intermediate sleeve section 24, a heat-shrinkable sheath
114 is fitted over the coil member 112. Preferably the sheath 114
is formed from a polyimide or polyolefin material which is expanded
radially outwardly and then shrunk down over the coil member 112
and outer sleeve 82 to secure the coil member 112 thereto. To
further secure the sheath 114 and coil member 112 in place, some
adhesive is provided between the sheath 114 and the intermediate
sleeve section 24. By covering the ends of the coil member 112, the
sheath 114 also lessens the chances of those ends providing a rough
edge or catch as the catheter 20 is advanced through the guide
catheter or artery.
[0047] Although the kirk-resistant structure is described and
illustrated in connection with a balloon dilatation catheter, it is
contemplated that such a structure be employed in any catheter
shaft as a transition from a first thin-walled, high strength
metallic tube structure to a second tube structure which is more
flexible than the metallic tube structure. Such a kink-resistant
structure, as described above (and also below in various
embodiments), may be employed in a single lumen catheter shaft, or
in multiple lumen catheter shaft having a central core tube such as
the multi-lumen shaft illustrated by the intermediate sleeve
section of the catheter disclosed in FIGS. 1-4.
Alternative Catheter Embodiment
[0048] Numerous alternative embodiments of the catheter of the
present invention are contemplated. For example, several
alternative arrangements for the main shaft section and
intermediate sleeve structure portion of the catheter are
illustrated and discussed herein, but it is not intended that the
illustrated embodiments are all inclusive of those structures and
designs which are included within the spirit and scope of the
present invention. In the following discussion of further
alternative embodiments of the present invention, to the extent a
component is identical to that of a previously described
embodiment, like reference numerals are used.
[0049] FIG. 4 illustrates an alternative embodiment for the distal
portion of a catheter according to the present invention.
Specifically, the outer sleeve (of the intermediate sleeve section)
and the distal balloon section are formed from the same component,
as a unitary member. Thus, proximal waist 36A of distal balloon
section 26A is elongated proximally and acts as the outer sleeve
for intermediate sleeve section 24A. A proximal end 115 of the
proximal waist 36A is sealably fixed about the core tube 80 and
main shaft section 22 adjacent the bonding region 74 thereof. It
should be understood that the prospect of having a unitary outer
sleeve and balloon member is applicable to all embodiments
disclosed herein and contemplated, although it is only illustrated
and discussed with respect to the catheter structure of FIG. 4.
[0050] FIG. 4 also shows another variation for the catheter's
structure illustrated in FIGS. 1-3. In FIG. 4, kink-resistant
structure 110A includes coil member 112A which is defined as a
spiral ribbon of stainless steel placed about a proximal portion of
the proximal waist 36 along the bonding region 74 and distally
therefrom. The coil member 112A does not have its coils uniformly
spaced apart, but rather has its coils spaced increasingly further
apart as the coil member extends distally from the main shaft
section 22. This results in a coil member 112A which becomes
increasingly more flexible, thereby "feathering out" the change in
relative stiffness and strain or kink relief between the relatively
inflexible main shaft section 22 and the relatively flexible
intermediate sleeve section 24A. As before, a heat-shrinkable
sheath 114A is fitted over the coil member 112A to further secure
the coil member 112A to the sleeve section 24A.
[0051] In FIG. 5, a modified main shaft section 22B is illustrated.
The main shaft section 22B is formed as a thin-walled, high
strength stainless steel tube or hypotube, but is defined as a
single tubular shaft 117 from its proximal end to its distal end
30B. The single shaft 117 has a longitudinally extending inflation
lumen 62B therethrough, and at its proximal end (not shown) the
single shaft 117 is mounted to an inflation device in a manner such
as that illustrated for the catheter of FIG. 2. Adjacent its distal
end 30B, the single shaft 117 has a longitudinal crimp 68B which
extends laterally inwardly from one side of the single shaft 117.
The single shaft 117 thus has three sections, a proximal,
relatively elongated tubular region 70B, a relatively short distal
transition region 72B and a relatively short distal bonding region
74B. The crimp 68B extends from its proximal origin in the
transition region 72B to its greatest lateral depth in the bonding
region 74B. The crimp 68B does not seal or close off the inflation
lumen 62B, but rather transforms the inflation lumen 62B from a
circular lumen to a half-moon lumen through the bonding region 74B,
as seen at 63B in FIG. 6. It is again understood that the use of a
single tube to define the main shaft section of the catheter of the
present invention is applicable to the other alternative
embodiments of the catheter structures disclosed herein.
[0052] FIGS. 5 and 6 also illustrate an alternative arrangement for
the kirk-resistant structure of the inventive catheter.
Kink-resistant structure 210 includes coil member 212. The sleeve
section 24B includes an outer sleeve 82B and an inner core tube
80B, with the core tube 80B adapted to be nested within and bonded
to the main shaft section 22B in its distal bonding region 74B. The
coil member 212 of the kink-resistant structure 210 is positioned
about the core tube 80B within the distal bonding region 74B and
extending distally therefrom. The coil member 212 is preferably
formed from stainless steel (either from a wire or ribbon) and may
have uniform coil spacing or increasingly spaced coils as the coil
member 212 extends distally from the main shaft section 22B. The
coil member 212 is secured to the core tube 80B by suitable means,
such as by embedding the coil member 212 in an epoxy layer 214
about the core tube 80B. A proximal end 100B of the outer sleeve
82B is bonded about the main shaft section 22B and inner tube 80B
and coil structure 210 in the bonding region 74B thereof, as seen
in FIGS. 5 and 6. In the intermediate sleeve section 24B, the inner
core tube 80B thus provides a guide wire lumen 52B therethrough,
and an annular inflation lumen 104B is provided, between the inner
tube 80B and outer sleeve 82B. Although the kink-resistant
structure 210 is within the annular inflation lumen 104 and the
outer sleeve 82B necks down distally front the main shaft section
22B, the size of the annular inflating lumen 104 is sufficient to
provide proper fluid flow to and from the catheter's balloon.
[0053] FIGS. 7-13 illustrate an alternative configuration for that
portion of the catheter adjacent the proximal inlet of the guide
wire lumen. Instead of providing a crimp structure in the distal
end of the main shaft section, an aperture is provided adjacent to
and proximal of the distal end of the main shaft section. The
aperture is aligned and sealably coupled to the inner tube to
define the guide wire lumen proximal outlet. In all disclosed
embodiments, the main shaft section is preferably formed from a
hypotube-like material.
[0054] As seen in FIG. 7, an alternative embodiment of the catheter
of the present invention has a proximal main shaft section 22C
formed from thin-walled, high strength stainless steel tubing. A
longitudinally extending inflation lumen 62C extends therethrough
from a proximal end of the main shaft section 22C to its distal end
30C. In the embodiment seen in FIG. 7, the main shaft 22C is formed
from two stainless steel tube sections, a proximal relatively long
shaft section 64C and a distal relatively short shaft section 66C
bonded on the distal end of the proximal section 64C. This two-part
main shaft section structure thus allows a substantial length of
the main shaft section 22C to be formed from the proximal shaft
section 64C which has a smaller diameter than the distal shaft
section 66C.
[0055] The distal shaft section 66C has an oval-shaped aperture 119
extending through its wall, with the oval being elongated in the
longitudinal direction of the main shaft section 22C. The aperture
119 is spaced proximally from a distal end of the distal shaft
section 66C (the distal end 30C of the main shaft section 22C). The
space between the aperture 119 and distal end 30C thus defines in
part a bonding region 121 for connecting the main shaft section 22C
to a distally extending intermediate sleeve section 24C.
[0056] As before, the intermediate sleeve section 24C includes an
inner core tube 80C and an outer sleeve 82C. A proximal end 88C of
the core tube 80C is sealably bonded about the aperture 119 to
align the proximal end 88C and aperture 119 and thereby define a
proximal outlet 92C for a guide wire lumen 52C extending through
the core tube 80C. As seen in FIG. 7, a proximal portion 123 of the
core tube 80C extends laterally from the aperture 119 into the
distal shaft section 66C and turns longitudinally and distally
relative thereto to be aligned generally coaxially therewith. As
such, the inflation lumen 62C is continued distally past the
aperture 119 as a generally annular inflation lumen 125, between
the core tube 80C and distal shaft section 66C (along the bonding
region 121). Proximal end 100C of the outer sleeve 82C is bonded
about the distal shaft section 66C in the bonding region 121 by a
suitable means, such as by epoxy or cyanoacrylate. As seen in FIG.
7, the outer sleeve 82C extends distally from the main shaft
section 22C over the core tube 80C and defines a longitudinally
extending annular inflation lumen 104C between the core tube 80C
and outer sleeve 82C. The proximal end 100C of the outer sleeve 82C
is sealed about the distal shaft section 66C so that the
longitudinal inflation lumens 62C, 125 and 104C are not compromised
to the exterior of the catheter, but are in fluid communication
therethrough.
[0057] In FIG. 7, kink-resistant structure 310 includes coil member
312 (of a wire or ribbon-like structure) which is bonded about the
outer sleeve 82C to extend distally from the distal end 30C of the
main shaft section 22C. In this embodiment, the coil member 312
does not extend about any portion of the main shaft 22C. The coil
member 312 is secured to the outer sleeve 82C by suitable adhesive
means, such as epoxy 314, and is embedded therein to firmly hold
the coil member 312 in place about the intermediate sleeve section
24C. In the embodiment of FIG. 7, the coil member 312 is
illustrated with its coils being spaced increasingly longitudinally
apart as the coil member 312 extends distally along the
catheter.
[0058] FIGS. 8-13 also illustrate embodiments of the catheter of
the present invention wherein an aperture is provided through the
main shaft section wall to accommodate the proximal outlet for the
relatively short, distal guide wire lumen. As opposed to the
embodiment of FIG. 7, however, the embodiments illustrated in FIGS.
8-13 show the main shaft section as a single shaft rather than as a
multi-part shaft. Indeed, FIG. 8 illustrates a catheter structure
identical to that of FIG. 7, except that the main shaft section 22D
is shown as a single shaft 217, rather than having proximal and
distal shaft sections 64C and 66C as seen in FIG. 7. As such, the
catheter inflation lumen includes longitudinally extending
inflation lumens 62D, 125D and 104D.
[0059] FIG. 9 is an embodiment of the catheter of the present
invention otherwise similar to FIG. 8, except that kink-resistant
structure 410 has coil member 412 with uniformly spaced coils along
the entire length. Again, the entire coil member 412 is fixed to
the outer sleeve 82C of the intermediate sleeve section 24C by
embedding the coil member 412 within a suitable material such as
epoxy or cyanoacrylate 414.
[0060] In the catheter structure of FIG. 10, intermediate section
24B has an inner core tube 80E and an outer sleeve 82E. The
structure of the catheter is otherwise the same as the catheter of
FIG. 9, except that the kink-resistant structure thereof is
positioned inside the outer sleeve 82E rather than outside of the
outer sleeve. Kink-resistant structure 510 is affixed to an inner
surface of the outer sleeve 82E distally of the main shaft section
22D by a suitable means, such as embedded adhesive 514. The
kink-resistant 510 includes coil member 512 which provides an
intermediate stiffener between the relatively stiff main shaft
section 22D and the relatively flexible intermediate sleeve section
24E. As seen, the outer sleeve 82E necks down distally from the
kink-resistant structure 510 to provide a lower profile for the
catheter in its distal regions. An annular inflation lumen 104E
formed between the inner tube 80E and outer sleeve 82E (and at a
proximal end thereof, between the inner tube 80B and the
kink-resistant structure 510) is not compromised by such a
necked-down sleeve design but maintained at sufficient size to
provide for adequate and quick inflation and deflation of the
balloon.
[0061] In FIG. 11 intermediate sleeve section 24F includes an inner
core tube 80F and an outer sleeve 82F. Kink-resistant structure 610
is mounted about the inner tube 80F along the bonding region 121
and extending distally from the main shaft section 22D into the
intermediate sleeve section 24F. The kink-resistant structure
includes coil member 612 which is affixed about the core tube 80F
by suitable means such as being embedded in epoxy or another
suitable adhesive 614. As seen in FIG. 11, the outer sleeve 82F has
an enlarged diameter at its proximal end to accommodate the main
shaft section 22D and the kink-resistant structure 610, and so that
the annular inflation lumens 125F and 104F about the core tube 80F
remain sufficiently large to provide proper inflation and deflation
pressures to the balloon of the catheter.
[0062] FIGS. 12 and 13 illustrate a further variation of the
kink-resistant structure of the present invention. In the
embodiments of FIGS. 12 and 13, the kink-resistance structure does
not include a coil member, is formed from a polymer tube which is
of intermediate stiffness between the main shaft section and
intermediate sleeve section. In FIG. 12, kink-resistant structure
710 is provided which is formed from a polyimide or other stiff
polymer tube 727. The tube 727 is bonded about an inner core tube
80G of the intermediate sleeve section 24G by a suitable adhesive,
such as epoxy or cyanoacrylate. The tube 727 extends through a
distal portion of the bonding region 121 and distally beyond the
main shaft section 22D into the intermediate sleeve section 24G.
Again, an outer sleeve 82G of the sleeve section 24G has an
enlarged diameter at its proximal end to accommodate the main shaft
section 22D and the kink-resistant structure 710, and so that the
components are dimensioned such that annular inflation lumens 125G
and 104G are not compromised.
[0063] In FIG. 13, kink-resistant structure 810 is illustrated, as
formed from a polyimide or other stiff polymer tube 829 which is
bonded to the inner surfaces of both the main shaft section 22D and
an outer sleeve 82H of an intermediate sleeve section 24H at a
bonding region 121H. The tube 829 thus provides not only a
kink-resistant structure to accommodate the change in stiffness of
the main shaft section and intermediate sleeve section, but also
provides a substrate for bonding the to catheter sections together
by a suitable adhesive, such as epoxy or cyanoacrylate. A core tube
80H of the sleeve section 24H extends through the interior of the
tube 829 to the aperture 119 on the main shaft section 22D. Thus,
an annular longitudinally extending inflation lumen 131 is formed
as a "bridge lumen" (between the core tube 80H and tube 829) from
the inflation lumen 62D to an annular inflation lumen 104H within
the sleeve section 24H.
[0064] As mentioned above, various combinations of these
alternative component and catheter structures are contemplated and
are intended to be considered, although not explicitly shown. For
example, it is contemplated that a two-part main shaft section
structure (such as illustrated in FIGS. 2, 4 and 7) may be combined
with any one of the kink-resistant structure such as that
illustrated in FIGS. 8-13. By way of example and not limitation, a
further example of such a combination may include the use of a
distal balloon section having an elongated proximal waist (such as
shown in FIG. 4) with any of the alternative kink-resistant
structures disclosed herein.
Conclusion
[0065] The balloon dilatation catheter of the present invention is
an over-the-wire catheter structure with a distal guide wire lumen
which optimizes the features of such a catheter in a way not
previously considered or achieved. The use of a hypotube-type main
shaft for the catheter allows the attainment of a high strength,
pushable shaft having thin walls and small diameter. The further
use of a two-part hypotube shaft structure allows an even smaller
diameter for the proximal elongated section of the main catheter
shaft. Employing a crimp as a means for aligning and creating a
proximal outlet for the relatively short guide wire lumen also
serves to provide a transition region for exit of the guide wire
from the catheter itself which is relatively gradual. The crimped
shaft design also provides additional stiffness in the transition
region where the guide wire enters and exits the catheter
proximally of the balloon thereof, thereby creating a more rigorous
catheter structure. Because the catheter of the present invention
is based upon a relatively stiff proximal main shaft section, and
such a catheter must have a relatively flexible distal portion for
working through the tortuous arterial anatomy, a strain relief or
kink-resistant structure is provided to make a more gradual
transition between the relatively stiff main catheter shaft and the
relatively flexible distal portion of the catheter. Various
configurations of strain relief and kink-resistant structures are
disclosed herein, and all are believed suitable to accomplish the
desired end of preventing significant closure of the guide wire
lumen and annular inflation lumen in the more flexible distal
portions of the catheter, especially adjacent the distal end of the
main catheter shaft.
[0066] Although the present invention has been described with
reference to preferred embodiments, workers skilled in the art will
recognize that changes may be made in form and detail without
departing from the spirit and scope of the invention.
* * * * *