U.S. patent application number 11/634239 was filed with the patent office on 2007-05-10 for catheter.
This patent application is currently assigned to Terumo Kabushiki Kaisha. Invention is credited to Tatsuzo Ishii.
Application Number | 20070106260 11/634239 |
Document ID | / |
Family ID | 27736570 |
Filed Date | 2007-05-10 |
United States Patent
Application |
20070106260 |
Kind Code |
A1 |
Ishii; Tatsuzo |
May 10, 2007 |
Catheter
Abstract
The catheter 1 has a tubular catheter body 2 made from a metal
material. A groove 21 is formed in the outer periphery of the
catheter body 2 in the longitudinal direction. This groove 21 is
formed by plastically transforming the tubular wall of the catheter
body 2 by plastic treatment. Thus, there is provided a catheter
which has excellent followability and high ease of operation while
maintaining torque transmissibility and pushability.
Inventors: |
Ishii; Tatsuzo; (Kanagawa,
JP) |
Correspondence
Address: |
BUCHANAN, INGERSOLL & ROONEY PC
POST OFFICE BOX 1404
ALEXANDRIA
VA
22313-1404
US
|
Assignee: |
Terumo Kabushiki Kaisha
|
Family ID: |
27736570 |
Appl. No.: |
11/634239 |
Filed: |
December 6, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10368432 |
Feb 20, 2003 |
7163524 |
|
|
11634239 |
Dec 6, 2006 |
|
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Current U.S.
Class: |
604/523 |
Current CPC
Class: |
A61M 25/104 20130101;
A61M 25/0021 20130101; A61M 25/0043 20130101 |
Class at
Publication: |
604/523 |
International
Class: |
A61M 25/00 20060101
A61M025/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 27, 2002 |
JP |
2002-052086 |
Feb 27, 2002 |
JP |
2002-052087 |
Claims
1. A catheter having a tubular catheter body made from a metal
material, wherein the catheter body has a groove formed in a
longitudinal direction in the outer periphery of at least the
distal end side portion thereof in such a manner that the tubular
wall is caved in; and the thickness of the tubular wall of the
catheter body is almost constant along the entire circumference
including the groove formed portion.
2. A catheter according to claim 1, wherein the groove is formed
along almost the entire length of the catheter body.
3. A catheter according to claim 1 which has a portion where the
depth of the groove decreases continuously or stepwise toward the
proximal end.
4. A catheter according to claim 1, wherein the catheter body is
made from stainless steel or pseudoelastic alloy.
5. A catheter according to claim 1 further comprising a tubular
member, made from a synthetic resin material, for covering the
outer periphery of at least the distal end side portion of the
catheter body and extending farther in the distal end direction
than the distal end of the catheter body.
6. A catheter according to claim 1, wherein plural slits are formed
in the tubular wall of the distal end side portion of the catheter
body and extend in a direction almost perpendicular to the
longitudinal direction of the catheter body.
7. A catheter according to claim 1, wherein spiral slits are formed
in the tubular wall of the distal end side portion of the catheter
body and wherein the spiral pitch between the spiral slits become
smaller continuously or stepwise toward the distal end.
8. A method of inserting a catheter into a blood vessel comprising:
inserting a guide wire into a blood vessel; inserting and advancing
a catheter along the guide wire in the blood vessel, the catheter
comprising a tubular catheter body made from a metal material and
possessing a groove formed in a longitudinal direction in the outer
periphery of at least the distal end side portion thereof in such a
manner that the tubular wall is caved in, the thickness of the
tubular wall of the catheter body is almost constant along the
entire circumference including the groove formed portion; turning
the catheter body such that the groove formed portion is positioned
on an inner side of a curvature of the blood vessel to permit the
catheter body to be bent in conformity to the curvature of the
blood vessel so that the catheter body can be advanced in the blood
vessel.
Description
[0001] This application is a divisional of U.S. Application No.
10/368,432 filed on Feb. 20, 2003 and claims priority under 35
U.S.C. .sctn. 120 to such application.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a catheter to be inserted
into a body lumen, vessel or duct such as a blood vessel for use.
The present invention also relates to a balloon catheter having a
balloon in the distal end portion thereof, and particularly, to a
rapid-exchange type balloon catheter.
[0004] 2. Description of the Related Art
[0005] In recent years, intravascular operations have been widely
performed to treat a lesion part of a blood vessel by inserting a
catheter into the blood vessel percutaneously without carrying out
a surgical operation. In these operations, a catheter must be
selectively inserted into an intricately bending, meandering or
branching narrow blood vessel to position its distal end portion at
the targeted site.
[0006] In general, in order to insert a catheter into the blood
vessel percutaneously, the catheter is made to reach the targeted
site while a guide wire (introduction aid tool) is inserted into
the lumen of the catheter. On this occasion, generally, the
catheter is preceded by a guide wire and advanced to the target
site in the blood vessel.
[0007] To guide the catheter having the guide wire inserted therein
into the targeted site of the body, the operation of moving forward
or backward or turning the guide wire and the catheter is carried
out from an end side in vitro thereof. This operation must be
transmitted to the distal end side of the catheter without fail.
Therefore, torque transmissibility and pushability are required for
the catheter.
[0008] When the body portion (catheter body) of a relatively thin
catheter having a small diameter to be applied to a narrow blood
vessel is made from a synthetic resin material, it may have low
stiffness or be readily kinked, whereby the above-mentioned torque
transmissibility and pushability may not be obtained fully.
Therefore, the catheter body of the relatively narrow catheter is
made of a metal tube having bending elasticity.
[0009] However, when the catheter body is made of a metal tube, the
distal end side portion of the catheter body especially has too
high flexural rigidity and lacks flexibility. Therefore, it is
inferior in follow-up ability (followability) which enables it to
follow the preceding guide wire in the winding blood vessel
smoothly and reliably.
[0010] A balloon catheter to be inserted into the blood vessel
typified by a catheter used for PTCA (Percutaneous Transluminal
Coronary Angioplasty) (to be referred to as "PTCA catheter"
hereinafter) has a guide wire lumen for inserting a guide wire
which is formed along the entire length of the catheter in addition
to a balloon lumen for inflating the balloon. Prior to the
insertion of the catheter into the blood vessel, the guide wire is
inserted into the guide wire lumen and the distal end portion of
the guide wire is guided to the targeted site (near a stricture in
the blood vessel) together with the catheter in such a manner that
the distal end of the guide wire precedes the catheter.
[0011] There are many variations of the PTCA catheter which differ
in the size of a balloon to be suited to a case of a disease such
as the size of the stricture site and the diameter of the blood
vessel or to expand the stricture site stepwise. After insertion
into the blood vessel, the work of exchanging the PTCA catheter may
be necessary. Even when a plurality of indwelling units for
securing an inner diameter in the blood vessel, called "stent", are
installed, the catheter may be removed from and inserted into the
blood vessel several times.
[0012] The exchange of the catheter described above is preferably
carried out while the guide wire is left in the blood vessel to
reduce a burden on a patient, the operation time and the labor, to
prevent infection, or the like.
[0013] However, since the guide wire lumen is formed along the
entire length of the conventional catheter as described above, in
order to exchange the catheter from the in-vitro end side (proximal
end side) of the guide wire while the guide wire is left in the
blood vessel, the in-vitro end of the guide wire must be projected
from the proximal end of the catheter to a length longer than the
total length of the catheter. That is, the length of the guide wire
must be twice or more the length of the catheter and there is a
problem that such long projecting guide wire reduces ease of the
operation.
[0014] There is proposed a rapid-exchange type catheter having a
guide wire lumen formed only in the distal end portion of the
catheter, that is, a catheter in which an opening at the distal end
of the catheter communicates with a side hole formed at a position
several centimeters away from the opening toward the proximal end
and this short lumen is engaged with a guide wire (EP 0397357 A1
(JP 4-9548 B)). This catheter can be exchanged while the guide wire
is left in the blood vessel without projecting the in-vitro end of
the guide wire long from the proximal end of the catheter.
[0015] In order to guide the catheter to the targeted site in vivo
while the guide wire is inserted in the guide wire lumen, as the
blood vessel meanders, the guide wire and the catheter must conform
to the curvature of the meandering blood vessel. In order to
conform to this curvature, the operation of moving forward or
backward or turning the guide wire and the catheter is carried out
on the in-vitro end side. This operation must be transmitted to the
distal end side of the catheter without fail. To this end, torque
transmissibility, pushability and kink resistance are required for
the catheter.
[0016] When the body portion (catheter body) of a relatively small
catheter to be applied to a narrow blood vessel is made from a
synthetic resin material, it may have low stiffness and be readily
kinked, whereby the above-mentioned torque transmissibility and
pushability may not be obtained fully. Therefore, the catheter body
of the relatively small catheter is made of a metal tube having
bending elasticity.
[0017] However, when the catheter body is made of a metal tube, the
distal end side portion of the catheter body especially has too
high flexural rigidity and lacks flexibility. Therefore, it is
inferior in follow-up ability (followability) which enables it to
follow the preceding guide wire in the winding blood vessel
smoothly and reliably.
SUMMARY OF THE INVENTION
[0018] It is an object of the present invention to provide a
catheter, balloon catheter or rapid-exchange type catheter which
easily winds in a specific direction and has excellent
followability and high ease of operation while securing torque
transmissibility and pushability.
[0019] This object is attained by the present invention described
as (1) to (11) in the following.
[0020] (1) A catheter having a tubular catheter body made from a
metal material, in which:
[0021] the catheter body has a groove formed in a longitudinal
direction in the outer periphery of at least the distal end side
portion thereof in such a manner that the tubular wall is caved in;
and
[0022] the thickness of the tubular wall of the catheter body is
almost constant along the entire circumference including the groove
formed portion.
[0023] (2) A balloon catheter including:
[0024] a tubular catheter body made from a metal material;
[0025] a balloon which can be inflated and deflated and is mounted
on the distal end side of the catheter body;
[0026] a balloon lumen which is formed of the lumen of the catheter
body and that communicates with the inside of the balloon; and
[0027] a guide wire lumen which is open to the distal end side of
the balloon, is surrounded by the tubular wall in the balloon and
has a guide wire inserted from the distal end side of the balloon
to the outside of the catheter body therein, in which:
[0028] the catheter body has a groove formed in a longitudinal
direction in the outer periphery of at least the distal end side
portion thereof in such a manner that the tubular wall is caved in;
and
[0029] the thickness of the tubular wall of the catheter body is
almost constant along the entire circumference including the groove
formed portion.
[0030] (3) A catheter or balloon catheter according to the item (1)
or (2) described above, in which the groove is formed along almost
the entire length of the catheter body.
[0031] (4) A catheter or balloon catheter according to any one of
the items (1) to (3) described above which has a portion where the
depth of the groove decreases continuously or stepwise toward the
proximal end.
[0032] (5) A balloon catheter according to any one of the items (2)
to (4) described above, in which at least the part of the guide
wire can be inserted into the groove.
[0033] (6) A balloon catheter according to any one of the items (2)
to (5) described above, in which an opening at the proximal end of
the guide wire lumen is formed continuous to the distal end portion
of the groove.
[0034] (7) A balloon catheter according to any one of the items (2)
to (6) described above, in which an inner tube is inserted into the
balloon and the guide wire lumen is formed of the lumen of the
inner tube.
[0035] (8) A catheter or balloon catheter according to any one of
the items (1) to (7) described above, in which the catheter body is
made from stainless steel or pseudoelastic alloy.
[0036] (9) A catheter or balloon catheter according to any one of
the items (1) to (8) described above which further has a tubular
member, made from a synthetic resin material, for covering the
outer periphery of at least the distal end side portion of the
catheter body and extending farther in the distal end direction
than the distal end of the catheter body.
[0037] (10) A catheter or balloon catheter according to any one of
the items (1) to (9) described above, in which plural slits are
formed in the tubular wall of the distal end side portion of the
catheter body and extend in a direction almost perpendicular to the
longitudinal direction of the catheter body.
[0038] (11) A catheter or balloon catheter according to any one of
the items (1) to (10) described above, in which spiral slits are
formed in the tubular wall of the distal end side portion of the
catheter body and in which the spiral pitch between the spiral
slits become smaller continuously or stepwise toward the distal
end.
BRIEF DESCRIPTION OF THE DRAWINGS
[0039] In the accompanying drawings:
[0040] FIG. 1 is a perspective view of Embodiment 1 of a catheter
of the present invention (guide wire is inserted into a lumen);
[0041] FIG. 2 is a sectional view (transverse sectional view) taken
along the line X-X of FIG. 1;
[0042] FIG. 3 is a perspective view of a catheter body of the
catheter shown in FIG. 1;
[0043] FIG. 4 is a perspective view of a catheter body in
Embodiment 2 of the catheter of the present invention;
[0044] FIG. 5 is a perspective view of a catheter body in
Embodiment 3 of the catheter of the present invention;
[0045] FIG. 6 is a plan view of Embodiment 4 of the catheter of the
present invention;
[0046] FIG. 7 is a sectional view (transverse sectional view) taken
along the line Y-Y of FIG. 6;
[0047] FIG. 8 is a sectional view (transverse sectional view) taken
along the line Z-Z of FIG. 6;
[0048] FIG. 9 is a graph showing an actual data on load and the
amount of deflection in a three-point bending test of a metal tube
on the vertical axis and the horizontal axis, respectively;
[0049] FIG. 10 is a perspective view showing a balloon catheter of
Embodiment 5 of the present invention inserted in a lumen of a
guiding catheter;
[0050] FIG. 11 is a longitudinal sectional view of the distal end
portion of the catheter shown in FIG. 10;
[0051] FIG. 12 is a sectional view (transverse sectional view)
taken along the line X-X of FIG. 10; and
[0052] FIG. 13 is a sectional view (transverse sectional view)
taken along the line Y-Y of FIG. 11.
DETAILED DESCRIPTION OF THE INVENTION
[0053] A catheter of the present invention will be described in
detail hereinafter based on preferred embodiments shown in the
accompanying drawings.
Embodiment 1
[0054] FIG. 1 is a perspective view of Embodiment 1 of a catheter
of the present invention (a guide wire is inserted into a lumen of
the catheter), FIG. 2 is a sectional view taken along the line X-X
of FIG. 1. (transverse sectional view), and FIG. 3 is a perspective
view of a catheter body of the catheter shown in FIG. 1. In the
following description, the right side (side close at hand of the
operation of inserting into the body) of each figure is referred to
as "proximal end" and the left side (distal end side to be inserted
into the body) is referred to as "distal end".
[0055] The catheter 1 shown in FIG. 1 includes a small and long
catheter body 2 having bending elasticity and a hub 4 mounted to
the proximal end of the catheter body 2. The constitution of each
element of the catheter will be described hereinafter.
[0056] The catheter body 2 is inserted into a body lumen, vessel or
duct such as a blood vessel (to be typified by a blood vessel
hereinafter) and is tubular. A tubular lumen (lumen) 23 is formed
in the catheter body 2 from the distal end to the proximal end
thereof. When the catheter body 2 is to be inserted into the blood
vessel, a guide wire 100 to be described below is inserted into the
tubular lumen 23. The tubular lumen 23 is also used as the passage
of a liquid such as physiological saline, medical fluid, cleaning
fluid, contrast medium or body fluid (such as blood).
[0057] This catheter body 2 is made from a metal material. Thus,
the catheter body 2 has higher rigidity (flexural rigidity and
torsional rigidity) than a catheter body made from a synthetic
resin material (plastic). Therefore, the catheter body 2 has high
stiffness even when its outer diameter is relatively small. As a
result, the catheter 1 becomes excellent in torque transmissibility
that torque applied from the proximal end can be transmitted to the
distal end without fail and in pushability that an operator's
push-in force for advancing the catheter in the blood vessel can be
transmitted to the distal end side from the proximal end side
without fail. It also becomes excellent in kink resistance.
[0058] That is, the catheter 1 of the present invention has high
ease of operation even when the outer diameter of the catheter body
2 is relatively small, whereby it can be preferably inserted into a
relatively narrow blood vessel, in particular. The outer diameter
(average outer diameter) of the catheter body 2 is not particularly
limited but preferably about 0.2 to 5 mm, more preferably about 0.3
to 3 mm. The inner and outer diameters of the catheter body 2 may
change in the longitudinal direction.
[0059] The length of the catheter body 2 is not particularly
limited and is suitably determined according to the use site of the
catheter 1 and a case of a disease but generally, it is preferably
about 80 to 200 cm.
[0060] The structural material of the catheter body 2 may be a
metal material but preferably a pseudoelastic alloy (super elastic
alloy) such as Ni--Ti alloy or stainless steel from the viewpoints
of physical properties and safety. That is, the pseudoelastic alloy
or stainless steel is readily returned to its original form by the
removal of stress. The pseudoelastic alloy includes what is
obtained by hot processing or cold processing, what is obtained by
both hot processing and cold processing, and further what is
obtained by another processing if it returns to its original form
after transformation. Therefore, it includes what has almost
constant stress even when distortion increases and what has
increasing distortion as stress grows in a stress-distortion
curve.
[0061] As shown in FIG. 1 and FIG. 2, a single groove (depression)
21 is formed in the outer periphery (side surface) of the catheter
body 2 in the longitudinal direction (axial direction) of the
catheter body 2 in such a manner that the tubular wall is caved
in.
[0062] The sectional form of the groove 21 is almost arcuate in
this embodiment. The sectional form is not limited to this and may
be V-shaped, U-shaped, rectangular, oval (semi-oval), or the
like.
[0063] The groove 21 is formed by plastically processing the
tubular wall of the catheter body 2 having a circular section to
plastically transform it. This plastic processing can be easily
carried out by the following methods, for instance. (1) The method
of which the unprocessed catheter body 2 is inserted into a flask
having a semi-circular section and an inner periphery with the same
curvature as that of the outer periphery (side surface) of the
catheter body 2, a jig (such as a pin) having a projection
corresponding to the groove 21 is installed at a position opposite
to the flask, and the catheter body 2 is moved relative to the
flask and the jig so that it is pulled out in the longitudinal
direction (axial direction) from between the flask and the jig
while the jig is applied to the catheter body 2 to form the groove
21 in the longitudinal direction gradually. (2) The method of which
a male mold having a projecting rib corresponding to the groove 21
is pressed against the outer periphery of the catheter body 2
supported in a flask and the groove 21 equal to the length of the
projecting rib is formed in one operation.
[0064] Since the tubular wall of a portion which has been pressed
by the projection of the above-mentioned jig or the projecting rib
of the above-mentioned male mold in the plastic processing escapes
toward the lumen side of the catheter body 2 to form a projection
22, the thickness of the tubular wall of the catheter body 2 is
almost constant along the entire circumference of the tube
including the groove 21 formed portion. As a result, the strength
of the groove 21 formed portion is not reduced and even when the
thickness of the tubular wall of the catheter body 2 is relatively
small, the deformation, damage, or the like of the groove 21 formed
portion can be effectively prevented.
[0065] Further, when the catheter body 2 is made from a
pseudoelastic alloy, the groove 21 may be formed simultaneously
with cold processing or hot processing or before or after cold
processing or hot processing.
[0066] Since the above-mentioned groove 21 is formed in the
catheter body 2, it has a property (characteristic) that its
flexural rigidity differs according to its bending direction. That
is, when the catheter body 2 is bent upward so that the groove 21
formed portion is located on the inner side (state shown by A in
FIG. 3), the flexural rigidity of the catheter body 2 is lower than
that when it is bent downward so that the groove 21 formed portion
is located on the outer side (state shown by B in FIG. 3) or when
it is bent sideways so that a portion 90.degree. away from the
groove 21 formed portion is positioned on the inner side (or outer
side) (state shown by C and D in FIG. 3). Thus, the catheter body 2
of the groove 21 formed portion is selectively readily bent in the
direction shown by A in FIG. 3.
[0067] As the catheter body 2 of the catheter 1 has the
above-mentioned property, it has excellent follow-up ability (to be
referred to as "followability" hereinafter) so that it can be
inserted along the preceding guide wire 100 in the winding blood
vessel smoothly and reliably. This is because when the catheter
body 2 is to be inserted and advanced along the preceding guide
wire 100, the catheter 1 is turned such that the groove 21 formed
portion is positioned on the inner side of curvature in conformity
to the curvature of the intricately branching and winding blood
vessel, whereby the catheter body 2 is readily bent in accordance
with the curvature of the blood vessel and thus can be inserted and
advanced smoothly and reliably.
[0068] Thus, the catheter 1 exhibits excellent followability.
Further, as described above, the catheter body 2 of the catheter 1
has high stiffness with relatively high rigidity so that the
catheter 1 has excellent torque transmissibility and pushability.
That is, the catheter 1 of the present invention has excellent
torque transmissibility and pushability as well as excellent
followability. Thus, it has extremely high ease of operation.
[0069] The inventor of the present invention conducted the
following three-point bending test on a metal tube to prove that
the flexural rigidity of the catheter body 2 is changed according
to its bending direction by the formation of the groove 21 as
described above. In this 3-point bending test, the amount of
deflection was measured when the metal tube was bent at 3 points
under the following conditions.
[0070] <Metal Tube>
[0071] material: SUS304, outer diameter: 0.55 mm, inner diameter:
0.33 mm, thickness: 0.11 mm, depth of groove 21: 0.09 mm
[0072] <Bending Conditions>
[0073] Fulcrum punch diameter: 5 mm, distance between fulcra: 10
mm, bending speed: 1 mm/min, maximum load: 0.98 kgf
[0074] FIG. 9 is a graph in which an actual measurement data on
load and the amount of deflection obtained in the above-mentioned
three-point bending test are plotted on the vertical axis and the
horizontal axis by a dotted line (measurement) and a solid line
(after adjusting the null point) . FIG. 9 shows data obtained (1)
when the catheter was bent upward (state shown by A in FIG. 3), (2)
when it was bent downward (state shown by B in FIG. 3), (3) when it
was bent sideways (state shown by C or D in FIG. 3) and (4) when
there was no groove (normal: before a groove was formed). As
understood from the results of null point-adjusted solid lines in
FIG. 9, the amounts of deflection under a load of 0.98 kgf in these
four cases are given below (the larger the amount of deflection,
the lower the flexural rigidity becomes). [0075] (1) Upward: 0.45
mm [0076] (2) Downward: 0.33 mm [0077] (3) Sideways: 0.30 mm [0078]
(4) No groove: 0.29 mm
[0079] It was found from the results of this three-point bending
test that flexural rigidity when the metal tube was bent upward so
that the groove 21 formed portion was located on the inner side was
lower than that when it was bent in other directions. It was also
found that flexural rigidity when it was bent downward and sideways
was almost the same as that when there was no groove.
[0080] In this embodiment, the groove 21 is formed along almost the
entire length of the catheter body 2. However, in the present
invention, the groove 21 may be formed in part of the catheter body
2, for example, only in the distal end side portion of the catheter
body 2.
[0081] Further, the sectional form, maximum depth, width and the
like of the groove 21 may be constant or may vary in the
longitudinal direction of the catheter body 2.
[0082] As shown in FIG. 1, X-ray impermeable markers 5 are formed
on the outer periphery of the distal end of the catheter body 2.
Thus, the position of the distal end of the catheter body 2 can be
confirmed by observation through a fluoroscope. In the illustrated
constitution, the X-ray impermeable markers 5 are formed by winding
a thin wire of gold, silver, platinum, tungsten or the like. The
form of the markers is not particularly limited and may be, for
example, sheet-like, band-like, C-shaped ring, or the like.
[0083] Furthermore, a layer of a hydrophilic polymer material (not
shown) having lubricity in a moist state is preferably formed on
the outer periphery of the catheter body 2. This reduces friction
when the catheter 1 is inserted, whereby the catheter 1 can be
inserted smoothly, thereby improving ease of operation and
safety.
[0084] The above-mentioned catheter body 2 is used by being
inserted into a guiding catheter (not shown) or contrast catheter
as required when it is inserted into the blood vessel.
[0085] As shown in FIG. 1, a hub 4 is firmly fixed to the proximal
end portion of the catheter body 2 liquid tightly, for instance.
The lumen of the hub 4 communicates with the proximal end of the
tubular lumen 23 of the catheter body 2.
[0086] The hub 4 serves as a port for inserting the guide wire 100
into the tubular lumen 23 of the catheter body 2, as a port for
injecting a liquid such as a medical fluid into the tubular lumen
23, and the like. The hub 4 also serves as a grip when the catheter
body 2 is operated.
[0087] The structural material of the hub 4 is not particularly
limited and may be, for example, a resin material such as polyvinyl
chloride, polyethylene, polypropylene, polycarbonate, polymethyl
methacrylate or an acrylonitrile-styrene-butadiene copolymer, or a
metal material such as stainless steel or titanium.
[0088] The guide wire 100 is a wire material having bending
elasticity, and its structural material is not particularly limited
and may be, for example, a plastic, pseudoelastic (super elastic)
alloy (such as Ni--Ti alloy) or metal material such as stainless
steel.
[0089] All or part of the surface of the guide wire 100 is
preferably subjected to a treatment for providing lubricity.
[0090] The distal end portion 101 of the guide wire 100 is bent in
its natural state (external force is not applied). When a blood
vessel is selected, the guide wire 100 and the catheter 1 are moved
forward or backward relative to each other to change the length of
projection of the distal end portion 101 of the guide wire 100 from
the opening at the distal end of the catheter body 2 according to
the situation.
[0091] That is, making use of the curvature of the distal end
portion 101 of the guide wire 100, the direction of the curvature
is changed to the direction of the targeted blood vessel by
rotation to insert the guide wire 100 into the targeted blood
vessel. At this point, a portion projecting from the catheter body
2 of the guide wire 100 is greatly bent in most cases. The position
of the groove 21 of the catheter body 2 is turned in conformity to
the bent guide wire 100 so that the groove 21 is located on the
depressed side (inner side) of the curvature of the guide wire 100.
Accordingly, as excessive force is not applied to the curvature of
the guide wire 100, the guide wire 100 is prevented from being
removed from the targeted blood vessel.
[0092] Thus, in the present invention, the distal end portions of
the guide wire 100 and the catheter body 2 can be bent in many ways
by combining the rotation of the catheter 1 with the relative
forward or backward movement of the guide wire 100 and the catheter
1. In the present invention, the use of these various bending
states makes it possible to move forward the guide wire 100 and the
catheter body 2 in the targeted direction smoothly and readily
while flexibly coping with the complex shape of the blood vessel
such as curved or branched.
[0093] A description is subsequently given of an example of usage
of the catheter 1.
[0094] The guide wire 100 is inserted into the tubular lumen 23 of
the catheter body 2 in advance.
[0095] Subsequently, an unshown guiding catheter or contrast
catheter is percutaneously inserted close to the targeted site of
the blood vessel (to be referred to as "targeted site" hereinafter)
by a Seldinger method or the like using an unshown guide wire.
[0096] Next, after the above-mentioned guide wire is pulled out,
the catheter body 2 of the catheter 1 of the present invention is
inserted into the above-mentioned guiding catheter (contrast
catheter), preceded by a new guide wire 100, until its distal end
portion reaches the targeted site.
[0097] When the distal end portion of the catheter body 2 reaches
the targeted site, the guide wire 100 is pulled out from the
catheter body 2.
[0098] Thereafter, an injection device such as a syringe, for
instance, is connected to the hub 4 to inject a contrast medium or
medical fluid. Thus, the contrast medium or medical fluid is
injected into the blood vessel from the distal end of the catheter
body 2 through the lumen of the hub 4 and the tubular lumen 23 of
the catheter body 2 in the stated order.
[0099] After the above operation has ended, the catheter body 2 is
pulled out from the blood vessel together with the above-mentioned
guiding catheter (contrast catheter).
Embodiment 2
[0100] FIG. 4 is a perspective view of a catheter body according to
Embodiment 2 of the catheter of the present invention. In FIG. 4,
in order to make it more understandable, the length in the
longitudinal direction of the catheter body 2a is shortened.
[0101] With reference to this figure, Embodiment 2 of the catheter
of the present invention will be described hereinafter, focusing on
the difference between the above-mentioned embodiment and this
embodiment. The explanation of the same items is omitted.
[0102] This embodiment is identical to the above-mentioned
Embodiment 1 except that the depth (maximum depth) of the groove 21
of the catheter body 2a decreases continuously (progressively
reduces) toward the proximal end of the catheter body 2a.
[0103] In the catheter body 2a of this embodiment, the depth of the
groove 21 becomes relatively larger toward the distal end and
relatively smaller toward the proximal end. As a result, the
catheter body 2a becomes more flexible with lower flexural rigidity
toward the distal end thereof when it is bent upward so that the
groove 21 formed portion is located on the inner side, and the
difference in ease of bending between the direction of bending
upward and other directions becomes smaller toward the proximal end
thereof. Therefore, more excellent followability is obtained on the
distal end side of the catheter body 2a and higher stiffness and
more excellent torque transmissibility and pushability can be
obtained on the proximal end side of the catheter body 2a. That is,
more excellent ease of operation can be obtained in this
embodiment.
[0104] The depth of the groove 21 of the catheter body 2a may be
partially constant in the longitudinal direction. The depth of the
groove 21 may also be null in part of the catheter body 2a. That
is, there may be no groove 21 in part of the catheter body 2a.
Embodiment 3
[0105] FIG. 5 is a perspective view of a catheter body according to
Embodiment 3 of the catheter of the present invention. In FIG. 5,
in order to make it more understandable, the length in the
longitudinal direction of the catheter body 2b is shortened.
[0106] With reference to this figure, Embodiment 3 of the catheter
of the present invention will be described hereinafter, focusing on
the difference between the above-mentioned embodiment and this
embodiment. The explanation of the same items will be omitted.
[0107] This embodiment is identical to the above-mentioned
Embodiment 1 except that the depth (maximum depth) of the groove 21
in the catheter body 2b decreases stepwise (progressively reduces)
toward the proximal end of the catheter body 2b.
[0108] In the catheter body 2b of this embodiment, the depth of the
groove 21 decreases in plural stages (three stages in the
illustrated constitution) toward the proximal end. That is, the
depth of the groove 21 is relatively large on the distal end side
of the catheter body 2b, relatively small on the proximal end side,
and intermediate in the middle portion between them. Accordingly,
the same effect as in Embodiment 2 can be obtained in this
embodiment.
[0109] Further, since portions having the same depth of the groove
21 have the same flexibility, the depth and length of the groove 21
are suitably changed according to the curvature of the targeted
site, thereby making it possible to easily obtain a catheter
suitable for all kinds of operations.
Embodiment 4
[0110] FIG. 6 is a plan view of Embodiment 4 of the catheter of the
present invention, FIG. 7 is a sectional view (transverse sectional
view) taken along the line Y-Y of FIG. 6, and FIG. 8 is a sectional
view (transverse sectional view) taken along the line Z-Z of FIG.
6.
[0111] With reference to these figures, Embodiment 4 of the
catheter of the present invention will be described hereinafter,
focusing on the difference between the above-mentioned embodiments
and this embodiment. The explanation of the same items will be
omitted.
[0112] This embodiment is identical to the above-mentioned
Embodiment 1 except that it has a tubular member 3 for covering the
outer periphery of the catheter body 2 and that plural slits 24 are
formed in the tubular wall of the distal end portion of the
catheter body 2.
[0113] As shown in FIG. 6 and FIG. 7, the tubular (cylindrical)
member 3 for covering the outer periphery of the catheter 1' of
this embodiment is formed along the entire length of the catheter
body 2.
[0114] The tubular member 3 is made from a synthetic resin material
and has flexibility. Examples of the synthetic resin material
constituting the tubular member 3 include: polyolefins such as
polypropylene, polyethylene and an ethylene-vinyl acetate
copolymer; polyesters such as polyethylene terephthalate (PET) and
polybutylene terephthalate (PBT); fluorine-based resins such as
polytetrafluoroethylene and an ethylene-tetrafluoroethylene
copolymer; resins having flexibility such as polystyrene-based
resin, polyamide, polyurethane and polyimide; polyamide elastomer,
polyester elastomer, polyurethane elastomer, polystyrene elastomer
and fluorine-based elastomer, or a combination of two or more out
of these (such as a laminate consisting of plural layers and
polymer blends thereof). Since the tubular member 3 is made from a
soft material having higher flexibility than the catheter body 2,
the resistance of the tubular member 3 can be substantially ignored
when the catheter body 2 is bent.
[0115] In this embodiment, as the outer periphery of the catheter
body 2 is covered with the tubular member 3 having such
flexibility, a stimulus to the inner wall of the blood vessel can
be further reduced, thereby increasing safety.
[0116] Further, in the catheter 1', the tubular member 3 extends
farther than the distal end 25 of the catheter body 2 in the
forward end direction. That is, as shown in FIG. 8, the distal end
portion of the catheter 1' is devoid of the catheter body 2 and
composed only of the tubular member 3. Thus, the distal end portion
of the catheter 1' has higher flexibility and can further reduce a
stimulus to the inner wall of the blood vessel, thereby making it
possible to obtain higher safety. Followability can also be further
improved. The length of a portion devoid of the catheter body 2 of
the distal end portion is not limited but is preferably 2 to 300
mm.
[0117] The outer periphery of the tubular member 3 is preferably
covered with a lubricant layer (not shown) of a hydrophilic (or
water-soluble) polymer material. Thus, when the outer periphery of
the tubular member 3 contacts blood, physiological saline, or the
like, the friction coefficient decreases and lubricity is provided,
thereby further enhancing the slidability of the catheter 1',
resulting in further improved torque transmissibility, pushability
and safety.
[0118] The tubular member 3 is not limited to the one covering the
total length of the catheter body 2 but may be the one covering at
least part of the outer periphery of distal end side of the
catheter body 2. In this case, the same effect as above can be
obtained.
[0119] Further, as shown in FIG. 6, in this embodiment, plural
slits 24 are formed in the tubular wall of a predetermined range on
the distal end side of the catheter body 2. In the illustrated
constitution, the slits 24 extend in a direction substantially
perpendicular to the longitudinal direction of the catheter body 2
and are arranged almost parallel to one another at predetermined
intervals. At the slit 24 formed sites, the flexibility of the
catheter body 2 becomes high, whereby the catheter 1' can obtain
higher followability.
[0120] The provision of the tubular member 3 prevents the contrast
medium or medical fluid injected into the tubular lumen 23 from
leaking from the slits 24.
[0121] Further, spiral slits may be formed in the tubular wall of
the distal end side portion of the catheter body 2 in place of the
plural slits 24. The same effect as above can be obtained in this
way as well. In this case, these spiral slits are preferably formed
in such a manner that the spiral pitch (interval) between the
spiral slits becomes smaller continuously or stepwise toward the
distal end. Thus, the distal end side portion of the spiral slit
formed portion can be made more flexible.
[0122] Furthermore, the slits may be formed in such a manner that
they extend in the longitudinal direction of the catheter body
2.
Embodiment 5
[0123] FIG. 10 is a perspective view showing a balloon catheter (to
be simply referred to as "catheter" hereinafter) of Embodiment 5 of
the present invention inserted in a lumen of a guiding catheter,
FIG. 11 is a longitudinal sectional view of the distal end portion
of the catheter shown in FIG. 10, FIG. 12 is a sectional view
(transverse sectional view) taken along the line X-X of FIG. 10,
and FIG. 13 is a sectional view (transverse sectional view) taken
along the line Y-Y of FIG. 11. The perspective view of a catheter
body of the catheter shown in FIG. 10 is shown in FIG. 3.
[0124] The catheter 31 shown in FIG. 10 is a rapid-exchange type
balloon catheter which includes a catheter body 32 having flexural
elasticity, an inflatable and deflatable balloon (expandable body)
33 which is mounted on the distal end side of the catheter body 32,
and a hub 4 mounted on the proximal end side of the catheter body
32. The constitution of each part will be described
hereinbelow.
[0125] The catheter body 32 is made from a metal material and is
tubular. Thus, the catheter body 32 has higher rigidity (flexural
rigidity and torsional rigidity) than a catheter body made from a
synthetic resin material (plastic). Therefore, the catheter body 32
has high stiffness even when its outer diameter is relatively
small. As a result, the catheter 31 has excellent torque
transmissibility so that torque applied from the proximal end side
is transmitted to the distal end side without fail and excellent
pushability so that an operator's push-in force for advancing the
catheter in the blood vessel can be transmitted from the proximal
end side to the distal end side without fail.
[0126] That is, the catheter 31 of the present invention obtains
excellent ease of operation even when the outer diameter of the
catheter body 32 is relatively small and is therefore particularly
suitable for use as a catheter having a relatively small diameter
which can be inserted into a relatively narrow blood vessel. Thus,
the outer diameter (average outer diameter) of the catheter body 32
is not particularly limited but is preferably about 0.2 to 3 mm,
and more preferably about 0.3 to 2 mm. The outer and inner
diameters of the catheter body 32 may change in the longitudinal
direction.
[0127] Further, the length of the catheter body 32 is not
particularly limited and suitably determined according to the site
of using the catheter 31 and a case of a disease. In general, it is
preferably about 100 to 200 cm.
[0128] As shown in FIG. 11, the lumen 23 of the catheter body 32
constitutes a balloon lumen 11 which communicates with the inside
of a balloon 33 to be described below. The balloon lumen 11 serves
as a passage for supplying a working fluid for inflating and
deflating the balloon 33 into the inside space of the balloon
33.
[0129] In the present invention, the provision of the groove 21
contributes to the reduction of the diameter of the guiding
catheter 200. That is, since the guide wire 100 is received in the
groove 21 in the catheter 31 as shown in FIG. 12, there is no need
to form a space for inserting the guide wire 100 between the outer
periphery of the catheter body 32 and the inner periphery of the
guiding catheter 200, whereby the guiding catheter 200 may have
almost the same small inner diameter as the outer diameter of the
catheter body 32. Accordingly, the guiding catheter 200 and the
catheter 31 can be inserted (introduced) into a narrower blood
vessel.
[0130] Further, since the guide wire 100 is received in the groove
21, the movement in the transverse direction of the guide wire 100
with respect to the catheter 31 is fixed and a play can be
eliminated. Since the guide wire 100 thus displaces together with
the catheter 31 at the time of operating the catheter 31, the
above-mentioned torque transmissibility and pushability become more
excellent.
[0131] Furthermore, this groove 21 also serves as a guide passage
for moving the guide wire 100 therealong.
[0132] In this embodiment, the groove 21 is formed along almost the
entire length of the catheter body 32. In the present invention,
the groove 21 may be formed only in the distal end side portion of
the catheter body 32.
[0133] The sectional form, maximum depth, width and the like of the
groove 21 may be constant or may vary in the longitudinal direction
of the catheter body 32.
[0134] As shown in FIG. 11, the balloon 33 is composed of a
cylindrical film member and connected (fixed) to the distal end
portion of the catheter body 32 by a cylindrical connection member
12. The balloon lumen 11 communicates with the inside of the
balloon 33 through the lumen of the connection member 12 from the
lumen of the catheter body 32.
[0135] The proximal end portion of the balloon 33 is sealed to the
outer periphery of the distal end portion of the connection member
12 air tightly or liquid tightly. The distal end portion of the
balloon 33 is sealed to the outer periphery of the distal end
portion of the inner tube 35 to be described below air tightly or
liquid tightly. The sealing of these portions is carried out by
fusion bonding or bonding with an adhesive, for example.
[0136] The balloon 33 is shriveled and folded before it is inflated
(deflated). It is inflated when a working fluid is supplied into
the inside of the balloon 33 (state shown in FIG. 10 and FIG.
11).
[0137] The structural material of the balloon 33 is a polymer
material (particularly, a thermoplastic resin). In this case, the
balloon 33 has flexibility as a whole but it is preferably made
from a material having relatively low elasticity (elongation).
[0138] Examples of the structural material of the balloon 33
include polyester resins such as polyethylene terephthalate and
polybutylene terephthalate; olefin-based resins such as polyester
elastomer, polyethylene and polypropylene; or those obtained by
crosslinking these resins (particularly, crosslinking by exposure
to an electron beam); vinyl chloride resin; polyamide-based resins
such as nylon 11, nylon 12 and nylon 610; polyamide elastomer;
polyurethane resin; an ethylene-vinyl acetate copolymer; or those
obtained by crosslinking these polymers; or polymer blends and
polymer alloys containing at least one of these.
[0139] Further, the balloon 33 may be composed of a laminate
consisting of plural films of these materials. In this case, the
laminate can be obtained by co-extrusion molding of layers or
assembling layers together by adhesion bonding, fusion bonding, or
the like, or forming one layer on another layer by coating, for
instance. A soft resin layer, layer of a lubricant material, layer
of an antithrombic material, or the like may also be formed on the
external side or internal side of a layer composed of one of the
above-mentioned materials.
[0140] The structural material of the balloon 33 may contain, for
example, an antithrombic material such as heparin, prostaglandin,
uroxinase or an arginine derivative.
[0141] The tubular inner tube 35 is arranged and inserted into the
inside (inner side) of the balloon 33 and the connection member 12.
A guide wire lumen 51 for inserting the guide wire 100 is formed in
the lumen of the inner tube 35.
[0142] The distal end portion of the guide wire lumen 51 (inner
tube 35) is open on the distal end side (distal end portion) of the
balloon 33 and the proximal end portion of the guide wire lumen 51
(inner tube 35) is open near a bonding portion between the catheter
body 32 and the connection member 12. That is, the guide wire lumen
51 communicates with the distal end side and the proximal end side
of the balloon 33.
[0143] The guide wire 100 is inserted into the guide wire lumen 51,
the distal end side of the guide wire 100 projects from the opening
53 at the distal end of the guide wire lumen 51, and the proximal
end side of the guide wire 100 is exposed to the outside of the
catheter 31 through the opening 52 at the proximal end of the guide
wire lumen 51 and is situated in the groove 21 almost parallel to
the catheter body 32.
[0144] X-ray impermeable markers 15 showing the boundaries between
the cylindrical portion and the conical portions of the balloon 33
when the balloon 33 is inflated are formed on the outer periphery
of the inner tube 35. The X-ray impermeable markers 15 are made of,
for example, a thin (having a small diameter) wire, band, or the
like of gold, silver, platinum, tungsten, etc.
[0145] Further, as shown in FIG. 13, the proximal end portion of
the inner tube 35 is inserted into the distal end portion of the
groove 21, and the inner periphery of the proximal end portion of
the connection member 12 is sealed to the proximal end portion of
the inner tube 35 and the outer periphery of the distal end portion
of the catheter body 32 air tightly or liquid tightly. Due to this
constitution, the opening 52 at the proximal end of the guide wire
lumen 51 is formed continuous to the distal end portion of the
groove 21. As shown in FIG. 11, since the guide wire 100 extends
linearly in the groove 21 from the guide wire lumen 51, it has low
resistance to sliding with the catheter 31, thereby making it
possible to carry out the operation of moving forward or backward
the catheter 31 and the guide wire 100 relative to each other
smoothly.
[0146] The length of the guide wire lumen 51 is not particularly
limited but is preferably about 3 to 30 cm, more preferably about 7
to 20 cm in consideration of the operation of exchanging the
catheter.
[0147] The structural materials of the connection member 12 and the
inner tube 35 are not particularly limited but preferably a polymer
material having flexibility includes, for example, a polyolefin
such as polyethylene, polypropylene, an ethylene-propylene
copolymer, an ethylene-vinyl acetate copolymer or a crosslinked
ethylene-vinyl acetate copolymer; thermoplastic or thermosetting
resin such as polyester, polyvinyl chloride, polyurethane,
polyamide, polyimide, polyamide elastomer, polyurethane elastomer,
polyester elastomer, polyfluororesin, or other.
[0148] As shown in FIG. 10, the hub 4 is mounted to the proximal
end portion of the catheter body 32. The lumen of the hub 4
communicates with the proximal end of the balloon lumen 11. A
balloon inflating device (not shown) such as a syringe is connected
to the hub 4 in order to supply a working fluid supplied therefrom
into the inside of the balloon 33 through the balloon lumen 11 or
extract the working fluid, thereby inflating or deflating the
balloon 33.
[0149] The working fluid for inflating the balloon is liquid
because it has an advantage that the volume of a liquid does not
change even when pressure is applied to the liquid whereas the
volume of a gas decreases when pressure is applied to the gas. In
addition, the liquid is used from the viewpoints of reduction of a
pressure loss and safety if, by any chance, the balloon ruptures. A
liquid having X-ray contrast properties is preferred as the liquid.
For example, a liquid prepared by diluting an X-ray contrast medium
such as a contrast medium for the artery with physiological saline
to several folds may be used.
[0150] Preferably, all or part of the surface of the guide wire 100
is subjected to a treatment for providing lubricity, the distal end
portion thereof is tapered corresponding to characteristic
properties such as butt resistance and bend resistance, and the
outer diameter thereof progressively decreases toward the distal
end. Accordingly, when the guide wire 100 is inserted into the
blood vessel from the distal end side thereof to reach the targeted
site (the coronary artery, etc.), the insertion of the guide wire
100 can be performed smoothly and the insertion operation can be
performed easily and safely while flexibly coping with the complex
shape such as curvature or branching of the blood vessel.
[0151] The above catheter 31 and the guide wire 100 are inserted
into the guiding catheter 200 before use. As shown in FIG. 12, the
guiding catheter 200 is a tubular member having flexibility and an
inner diameter larger than the outer diameter of the catheter body
32. The structural material of the guiding catheter 200 is not
particularly limited but may be the same as the structural material
of the connection member 12 and the inner tube 35, for example.
[0152] As shown in FIG. 10, a Y connector 300 is mounted on the
proximal end side of the guiding catheter 200. A lumen is formed
inside of the Y connector 300 in the longitudinal direction and
this lumen communicates with the lumen of the guiding catheter 200.
The catheter 31 and the guide wire 100 project from the proximal
end of the Y connector 300 through the lumens of the guiding
catheter 200 and the Y connector 300.
[0153] Further, a tubular branched portion 310 is formed on the Y
connector 300. This branched portion 310 is used, for example, to
inject an X-ray contrast medium into a desired targeted site in the
blood vessel. The X-ray contrast medium injected from the branched
portion 310 is discharged from the opening at the distal end of the
guiding catheter 200 through the lumen of the Y connector 300 and
the lumen of the guiding catheter 200.
[0154] The catheter of the present invention has been described
above with reference to the illustrated embodiments. However, the
present invention is not limited to these and components
constituting the catheter may be substituted by any arbitrary known
components which can exhibit the same functions. Any arbitrary
known component may also be added.
[0155] A description is subsequently given on usage when the
catheter 31 is applied to PTCA. [0156] [1] According to the
Seldinger method, a catheter introducer is stuck into a femoral
artery (or brachial artery), and the guiding catheter 200
containing a guide wire (not shown) is inserted into the artery
from the sheath of the catheter introducer, moved forward or
backward or turned repeatedly while the guide wire precedes the
guiding catheter 200 until the distal end portion thereof reaches
the inlet of the coronary artery and is left there. [0157] [2]
After the above-mentioned guide wire is pulled out, the catheter 31
having the guide wire 100 situated in the groove 21 and the guide
wire lumen 51 is inserted from a hemostatic valve provided in the
opening at the proximal end of the Y connector 300 and moved
forward along the lumen of the guiding catheter 200 toward the
distal end direction, preceded by the guide wire 100, and the
distal end portion of the catheter 31 is projected from the opening
at the distal end of the guiding catheter 200. In the present
invention, as described above, the catheter 31 can be advanced
smoothly and quickly while it is turned as required in accordance
with the curvature of the guiding catheter 200 and the curvature of
the blood vessel. [0158] [3] When the distal end of the catheter 31
reaches the coronary artery, the guide wire 100 is moved forward
while it is turned as required so that the distal end thereof
passes through the stricture of the coronary artery which is the
targeted site. In the present invention, since the guide wire 100
is received in the groove 21, it is also turned by the rotation of
the catheter 31 described above and is not twined around the outer
periphery of the catheter body 2, thereby improving the operation
ease of the guide wire 100. Therefore, the work of passing the
guide wire 100 through the stricture of the coronary artery can be
carried out readily and reliably.
[0159] During this, the X-ray contrast medium is injected from the
branched portion 310 of the Y connector 300 to be supplied into the
coronary artery through the lumens of the Y connector 300 and the
guiding catheter 200 to create an image for confirming the
position. [0160] [4] When the distal end of the guide wire 100 has
passed through the stricture of the coronary artery, the
advancement of the guide wire 100 is stopped and then the catheter
31 is advanced along the guide wire 100 slowly to position the
balloon 33 in the stricture of the coronary artery using the X-ray
impermeable markers 15 as a clue.
[0161] Then, the working fluid is injected from the hub 4 to be
supplied into the balloon 33 through the lumen of the hub 4 and the
balloon lumen 11 to inflate the balloon 33 at 4 to 18 atm, which
differs according to the size of the balloon 33. Thus, the
stricture of the coronary artery is expanded. [0162] [5] To further
expand the stricture of the coronary artery from this state, for
example, the inserted catheter is exchanged with a catheter
suitable therefor that has a larger balloon.
[0163] To exchange the catheter 31 inserted into the coronary
artery with a new catheter, the balloon 33 is deflated while the
guide wire 100 and the guiding catheter 200 are left as they are
and then the hub 4 is pulled toward the proximal end to retreat the
catheter 31 and pull it out. Since the proximal end of the guide
wire 100 is fixed by the finger or the like, the catheter 31 can be
pulled out while the guide wire 100 is left in the body.
[0164] The proximal end of the guide wire 100 is inserted into a
hole at the distal end of the new catheter to be exchanged (balloon
catheter, etc.), and the catheter is moved forward along the guide
wire 100 to reach the targeted site through the Y connector 300 and
the lumen of the guiding catheter 200 in the same manner as
described above. As a result, exchange of the catheter is
completed. Thereafter, operation is carried out according to the
purpose of the exchanged catheter.
[0165] The balloon catheter of the present invention has been
described above with reference to the illustrated embodiments.
However, the present invention is not limited to these and
components constituting the balloon catheter may be substituted by
any arbitrary known components which can exhibit the same
functions. Any arbitrary known components may also be added.
Effect of the Invention
[0166] As described above, according to the present invention,
there is obtained a catheter which has a simple structure,
excellent torque transmissibility, pushability and followability
and allows extremely high ease of operation.
[0167] Further, when the catheter body has a portion where the
depth of the groove decreases continuously or stepwise toward the
proximal end thereof, torque transmissibility, pushability and
followability can be further improved.
[0168] Further, when the groove of the catheter body is formed by
plastically transforming the tubular wall of the catheter body, the
catheter can be produced easily and the above-mentioned effect can
be obtained at lower production cost.
[0169] Further, when there is provided a tubular member for
covering the outer periphery of at least the distal end side
portion of the catheter body, which is made from a synthetic resin
material, higher safety is obtained.
[0170] Further, when at least part of the guide wire can be
inserted into the groove of the catheter body, the guide wire can
be used in combination with a guiding catheter having a smaller
diameter and can be inserted into a narrower blood vessel.
[0171] Furthermore, when the groove of the catheter body is formed
by plastically transforming the tubular wall of the catheter body,
the catheter can be produced easily and the above-mentioned effect
can be obtained at lower production cost.
* * * * *