[0001] The present invention generally relates to the structure of infusion devices for
infusing a predetermined reagent to lesion portions, for example, in body tissue.
An infusion device according to the preamble of claim 1 is described for example US-A-4808156.
[0002] Conventionally, medical devices such as catheters have been introduced into tubular
organs in the body such as blood vessels, the alimentary canal, and the ureters to
perform various treatments, tests, and procedures, for example. More recently, treatment
and procedures in which infusion devices such as infusion catheters have been used
to infuse a predetermined liquid medicine into lesion portions in body tissues have
been performed (see JP 2001-104487A and JP 2001-299927A).
[0003] That is, as is well known in the art, such infusion catheters are constituted by
a tubular catheter member into which a needle-shaped tube member made of a narrow
tube capable of conducting a predetermined reagent and having a sharp tip portion
is inserted and disposed in such a manner that it can move in the axial direction
of the catheter member. The catheter member of such an infusion catheter is then inserted
into a blood vessel and pushed through the vessel until reaching the site of a lesion
in a body tissue, at which point the needle-shaped tube member is moved longitudinally.
The needle-shaped tube member is thereby passed through a tip opening or an aperture
portion provided in the tube wall of the catheter member and the needle portion of
the tip of the needle-shaped tube member is extruded to the outside to penetrate a
lesion portion of the body tissue, and in this state a predetermined reagent is infused
into the lesion portion through the needle-shaped tube member.
[0004] One type of an infusion device, such as an infusion catheter, has a structure in
which at least three lumens are provided inside the tubular member, these being a
needle-shaped tube member lumen into which the needle-shaped tube member is movably
inserted, a guide wire lumen into which a guide wire is inserted, and a balloon lumen
for conducting fluid for expanding a balloon that is attached to the outside of the
tubular member.
[0005] In infusion devices having such a structure, it is not possible to keep the cross
sectional area of the tubular member perpendicular to its axial direction from becoming
large. For that reason, when using such infusion devices there is the concern that
depending on the site in the body to which it is to be inserted it may be difficult
to insert the tubular member into the body, even if the tubular member has an annular
profile perpendicular to its axis such that it can be inserted into the body as smoothly
as possible. Moreover, there is also a concern that the flow of blood may be arrested
when the tubular member has been inserted into a blood vessel, for example.
Summary of the Invention
[0006] The present invention was arrived at in consideration of the foregoing matters, and
it is an object thereof in an embodiment to provide an infusion device having a tubular
member in which at least three lumens are provided, which can be easily inserted into
the body and which allows the flow of blood through a blood vessel to be reliably
secured even if the tubular member has been inserted into that blood vessel.
[0007] In order to solve the above problems, a primary aspect of an embodiment of the present
invention is disclosed in claim 1. Accordingly, there is claimed an infusion device
having a tubular member, made of a tube member that can be inserted into a body, in
which at least three lumens are provided, a needle-shaped tube member, made of a thin
tube with a sharp tip, that is inserted into any one of the three lumens inside the
tubular member such that it can be moved axially and whose sharp tip is extruded outside
through an extrusion aperture provided in the tubular member so as to infuse a reagent
(including at least one of natural or synthetic chemical components and biological
elements such as cells, tissues, and biologically-derived or altered or natural components
and any other components suitable for treatment), and a reagent supplier for supplying
a predetermined reagent into the needle-shaped tube member, wherein when the tubular
member has been inserted and placed within a body, the tip portion of the needle-shaped
tube member is extruded from the extrusion aperture of the tubular member and penetrated
into predetermined tissue within the body, such that a reagent that is supplied 'from
the reagent supplier can be infused into that body tissue through the needle-shaped
tube member, wherein a recessed portion extending in the axial direction is formed
in an outer circumferential surface of the tubular member, such that a cross sectional
shape of the tubular member perpendicular to the axial direction is a shape in which
at least a portion of an outer circumference of an annular shape has been recessed
radially inward.
[0008] In other words, with the infusion device according to an embodiment of the present
invention, a recessed portion is formed in the outer circumferential surface of the
tubular member such that the tubular member has a cross sectional shape perpendicular
to its axis in which at least a portion of outer circumference of an annular shape
has been recessed radially inward. Thus, compared to the tubular member of conventional
devices, in which three or more lumens are formed therein and whose cross sectional
shape perpendicular to its axis is annular, the cross sectional area in the direction
perpendicular to the axis is reduced by an amount corresponding to the recessed portion
that is formed. Thus, the geometrical moment of inertia is small and the tubular member
is easily bent. Consequently, the tubular member easily follows areas within the body,
such as blood vessels, into which it is inserted. Thus, the tubular member can be
more smoothly inserted into the body than the tubular member of a conventional device.
[0009] Moreover, in the infusion device according to an embodiment of the present invention,
the recessed portion formed in the outer circumferential surface of the tubular member
extends in the axial direction of the tubular member. Thus, for example, when the
tubular member has been inserted into a blood vessel, the presence of this recessed
portion allows a gap through which blood can flow to be reliably formed between the
outer circumferential surface of the tubular member and the inner wall surface of
the blood vessel.
[0010] Consequently, with the infusion device according to an embodiment of the present
invention described above, the tubular member can be easily inserted into the body,
even it is internally provided with at least three or more lumens.
[0011] To solve the technical issues discussed above, a further aspect of an embodiment
of the present invention is an infusion device having a tubular member, made of a
tube member that can be inserted into a body, in which at least three lumens are provided,
a needle-shaped tube member, made of a thin tube with a sharp tip, that is inserted
into any one of the three lumens inside the tubular member such that it can be moved
axially and whose sharp tip is extruded outside through an extrusion aperture provided
in the tubular member so as to infuse a reagent, and a reagent supplier for supplying
a predetermined reagent into the needle-shaped tube member, wherein when the tubular
member has been inserted and placed within a body, the tip portion of the needle-shaped
tube member is extruded from the extrusion aperture of the tubular member and penetrated
into predetermined tissue within the body, such that a reagent that is supplied from
the reagent supplier can be infused into that body tissue through the needle-shaped
tube member, wherein the tubular member, in a cross-section perpendicular to its axial
direction, has an outer circumferential surface made of three convex curved corner
portions each positioned corresponding to apexes of a triangle that is formed having
the center points of any three lumens of the at least three lumens serving as its
apexes, and three lateral surfaces that are curved surfaces or flat surfaces each
positioned corresponding to the bases of this triangle and connecting convex curved
corner portions that are adjacent.
[0012] That is, in the infusion device according to an embodiment of the present invention,
the tubular member has an outer circumferential surface formed only by three convex
curved corner portions and three lateral surfaces, which are either curved surfaces
or flat surfaces. Thus, with this infusion device, the cross sectional shape perpendicular
to the axial direction of the tubular member is substantially triangular, having three
rounded corner portions and three bases constituted by straight or curved lines. The
cross sectional area perpendicular to the axial direction of the tubular member can
therefore be made sufficiently smaller than the cross sectional area of the tubular
member of a conventional device, in which three or more lumens are provided inside
the tubular member and its cross sectional shape perpendicular to its axis is annular.
Thus, the geometrical moment of inertia is small and the tubular member is easily
bent. The tubular member therefore easily follows areas within the body, such as blood
vessels, into which it is inserted. Consequently, the tubular member can be more smoothly
inserted into the body than the tubular member of a conventional device.
[0013] Moreover, in the infusion device according to an embodiment of the present invention,
the tubular member has three lateral surfaces which are curved or flat surfaces and
which provide the three bases of the cross section shape in the direction perpendicular
to the axis that give a substantially triangular shape. Thus, for example, when the
tubular member has been inserted into a blood vessel, a gap that allows blood to flow
therethrough can be reliably formed between these three lateral surfaces and the inner
wall surface of the blood vessel.
[0014] Consequently, the infusion device according to an embodiment of the present invention
described above can be easily inserted into the body even though at least three lumens
are provided within it. It also allows the flow of blood within a blood vessel into
which it has been inserted to be reliably secured.
[0015] It should be noted that in one preferable configuration of the foregoing infusion
device according to an embodiment of the present invention, a maximum width in the
direction of extrusion of the needle-shaped tube member from the extrusion aperture
in a cross section of the needle-shaped tube member taken perpendicular to the axial
direction is smaller than a maximum width in a direction perpendicular to the direction
of extrusion of the needle-shaped tube member in that cross section.
[0016] In an infusion device having this configuration, the tubular member can be easily
curved in the direction in which the needle-shaped tube member is extruded from the
extrusion aperture. Thus, when the tubular member has been inserted into the body,
it is easily curved along contours within the body, making insertion of the tubular
member into the body easy. Further, the section of the tubular member with a large
width, that is, the section whose area is large, is brought into close contact with
a section in the body due to the reaction force when the needle-shaped tube member
is extruded from the extrusion opening and penetrates body tissue, and thus the tubular
member can reliably receive and stop the reaction force resulting from this penetration
by the needle-shaped tube member. The needle-shaped tube member can therefore be easily
and reliably advanced into body tissue.
[0017] In another favorable embodiment of the infusion device according to an embodiment
of the present invention, the front end portion of the needle-shaped tube member in
the direction of insertion into the body is smaller in a cross section of the tubular
member taken perpendicular to the axial direction than in a section other than the
front end portion of the tubular member.
[0018] In an infusion device having this configuration, the front end portion of the tubular
member, whose sectional area perpendicular to the axial direction has been made small,
can be provided with flexibility. Thus, the tubular member can be safely inserted
into the body without damaging inner wall surfaces within the body. Furthermore, reducing
the cross sectional area of the tubular member in a section perpendicular to the axial
direction in the front end portion has the added benefit that when the tubular member
has been inserted into a blood vessel the flow of blood through that blood vessel
can be favorably secured.
[0019] In yet another preferable embodiment of the infusion device according to an embodiment
of the present invention, the at least three lumens provided in the tubular member
include a needle-shaped tube member lumen into which the needle-shaped tube member
is inserted, a first guide wire lumen into which a first guide wire that is extended
from a tip of the tubular member is inserted such that it can be moved in the axial
direction of the tubular member, and a balloon lumen for supplying fluid into a balloon
that can expand and contract and that is attached to an outside portion of the tubular
member.
[0020] With an infusion device having the foregoing configuration, even if the tubular member
is inserted up to a predetermined site within a blood vessel and the balloon is expanded
at that site, for example, the flow of blood can be satisfactorily secured.
[0021] In a yet further preferable embodiment of the infusion device according to an embodiment
of the present invention, the at least three lumens provided in the tubular member
include a needle-shaped tube member lumen into which the needle-shaped tube member
is inserted, a first guide wire lumen into which a first guide wire that is extended
from a tip of the tubular member is inserted such that it can be moved in the axial
direction of the tubular member, and a second guide wire lumen into which a second
guide wire that is extended in a direction intersecting the first guide wire is inserted
such that it can be moved in the axial direction of the tubular member, and a plane
that includes the direction vector in which the first guide wire is extended and a
direction vector in which the second guide wire is extended is substantially perpendicular
to the direction in which the extrusion aperture is provided.
[0022] In an infusion device having such a configuration, the plane that includes the direction
vector in which the first guide wire is extended and the direction vector in which
the second guide wire is extended is substantially approximate to the surface of the
body tissue that is to be penetrated. Also, the plane including direction of extrusion
of the needle-shaped tube member that is extruded from the extrusion aperture of the
tubular member and the axial direction of the tubular member is substantially perpendicular
to the plane including the direction vectors for the first and second guide wires.
The needle-shaped tube member can therefore be extruded from the extrusion aperture
of the tubular member in a direction that is substantially perpendicular to the surface
of the body tissue to be penetrated. Thus, the needle portion can be penetrated into
a desired location of a lesion portion of body tissue.
[0023] Furthermore, in this infusion device, most of the reaction force that is generated
as the needle-shaped tube member is advanced into body tissue when the needle-shaped
tube member is penetrated into the body tissue is applied in a direction substantially
perpendicular to the surface of the body tissue, that is, a direction substantially
perpendicular to the plane including the direction vector in which the first guide
wire is extended and the direction vector in which the second guide wire is extended
and which is opposite to the direction in which the needle-shaped tube member is advanced.
Thus, this reaction force is divided between the first guide wire and the second guide
wire and is thereby sufficiently and reliably stopped. As a result, the needle-shaped
tube member can be very smoothly and reliably advanced into body tissue.
[0024] Consequently, with the infusion device having the foregoing configuration, the needle-shaped
tube member can be reliably penetrated into a predetermined site of body tissue up
to a desired depth, even if the body tissue that penetrates is relatively hard. As
a result, a greater effect with treatment or procedures in which a predetermined liquid
medicine is infused into a lesion portion can be attained.
[0025] It should be noted that strictly speaking, "substantially perpendicular" here is
used taking into account that there may be cases in which the needle-shaped tube member
is not extruded perpendicular to a portion of the surface of the body tissue due to
the fact that in practice, the surface of body tissue has a complex shape. In other
words, in an embodiment of the present invention, the state of the plane including
the direction vector in which the first guide wire is extended and the direction vector
in which the second guide wire is extended being substantially perpendicular to the
direction in which the extrusion aperture is provided also includes the state of that
plane intersecting the direction in which the extrusion aperture is provided at an
angle that is approximate to a right angle.
[0026] Further, in the infusion device, if the first guide wire and the second guide wire
are inserted into the first guide wire lumen and the second guide wire lumen, respectively,
then, preferably, the first guide wire lumen and the second guide wire lumen are provided
within the tubular member such that the plane including the central axis of the first
guide wire lumen and the central axis of the second guide wire lumen is perpendicular
to the direction in which the extrusion aperture is provided.
[0027] In an infusion device having such a configuration, the needle-shaped tube member
can be more reliably extruded from the extrusion aperture of the tubular member in
a direction that is substantially perpendicular to the plane including the direction
of extension of the first guide wire and the direction of extension of the second
guide wire. Thus, most of the reaction force that is generated when the needle portion
is advanced into body tissue is more adequately and reliably received and stopped
by the first guide wire and the second guide wire. As a result, the needle portion
can be even more smoothly and reliably advanced into body tissue.
[0028] Further, in an infusion device having a structure in which the first and the second
guide wires are inserted into first and second guide wire lumens as described above,
it is preferable that the first guide wire lumen and the second guide wire lumen are
provided within the tubular member such that they are disposed on either side of the
needle-shaped tube member and sandwich it between them, and that their central axes
are located on the same plane as the central axis of the needle-shaped tube member
lumen.
[0029] By adopting such a configuration, the distance between the first and the second guide
wire lumens can be made as large as possible, and the distance between the first and
the second guide wires that are extended outward from the first and the second guide
wire lumens can also be made large. As a result, most of the reaction force that is
generated when the needle portion is advanced into body tissue is more adequately
and reliably received by the first guide wire and the second guide wire.
[0030] Yet further, in the infusion device according to an embodiment of the present invention,
if a structure in which the first guide wire and the second guide wire are inserted
into the first guide wire lumen and the second guide wire lumen is adopted, then it
is preferable that a balloon that can be expanded and contracted is attached to the
outside of the tubular member, and that a balloon lumen for conducting for expanding
the balloon is further provided within the tubular member.
[0031] If such a configuration is adopted, then by expanding the balloon the tubular member
can be easily fastened to a predetermined site in the body. This allows the needle-shaped
tube member to more reliably penetrate a predetermined location in body tissue up
to a desired depth.
[0032] Also, if a balloon and a balloon lumen are provided outside and inside the tubular
member as described above, then the four lumens are preferably provided within the
tubular member such that the plane that includes the central axes of the first guide
wire lumen and the second guide wire lumen and the plane that includes the central
axes of the needle-shaped tube member lumen and the balloon lumen are positioned perpendicular
to one another. The four lumens are thus disposed well balanced within the tubular
member. As a result, tasks in which an infusion device having such a tubular member
is employed can be carried out more smoothly.
[0033] Further, in the infusion device according to an embodiment of the present invention,
if a structure in which a balloon and a balloon lumen are provided outside and inside
the tubular member is adopted, then it is preferable that the balloon lumen and the
needle-shaped tube member lumen are provided within the tubular member such that the
center of the extrusion aperture is located on a plane that includes their central
axes. By doing this, the balloon lumen is disposed with greater balance within the
tubular member. Thus, tasks in which the infusion device is employed can be carried
out more smoothly.
[0034] In another embodiment, the present invention provides an infusion device, comprising:
(i) a tubular member, made of a tube member that can be inserted into a body, in which
at least three lumens are provided; (ii) a needle-shaped tube member, made of a thin
tube with a sharp tip, that is inserted into one of the three lumens inside the tubular
member such that it can be moved axially, and whose tip is extruded outside through
an extrusion aperture provided in the tubular member so as to infuse liquid medicine;
and (iii) a recessed portion formed in an outer circumferential surface of the tubular
member and extending in the axial direction thereof, such that a cross sectional shape
of the tubular member perpendicular to the axial direction is a shape in which at
least a portion of the outer circumference of an annular cross section has been recessed
radially inward.
[0035] Further, in another embodiment, the present invention provides an infusion device,
comprising: (i) a tubular member configured to be inserted into a body, having at
least three lumens extending in its axial direction and an extrusion aperture provided
on a side wall of the tubular member, one of said lumens leading to the extrusion
aperture, said tubular member having a cross section perpendicular to the axial direction;
and (ii) a needle-shaped tube member with a sharp tip, that is inserted into said
one of the lumens and is movable axially, said tip being extruded outside through
the extrusion aperture for infusing a reagent, wherein the cross section has an outer
periphery formed from an imaginary circle by moving inward a portion of the circle
corresponding to at least one side of an imaginary polygon, where the imaginary polygon
having apexes is defined by the center points of the lumens and has sides each connecting
two adjacent apexes, and the imaginary circle has a smallest diameter for fitting
the cross section inside, wherein the imaginary polygon is fitted therein. The outer
periphery may be composed of concave, convex, and/or straight lines. Any combination
can be adopted in view of flexibility, rigidity, and a function of allowing for blood
flow. The lumens need to be formed with a material having a thickness for sufficient
mechanical strength, whereas a portion apart from the lumens can be thin. The above
embodiment further includes, but is not limited to, the following additional embodiments:
[0036] The at least three lumens may be three lumens at the front end portion and four lumens
at a rear end portion opposite to the front end portion.
[0037] The four lumens may include a first guide wire lumen into which a first guide wire
that is extended from a tip of the tubular member is inserted and movable axially,
and a second guide wire lumen into which a second guide wire that is extended from
an opening provided on a side wall in a different direction from the first guide wire
is inserted an movable axially, wherein the second guide wire lumen ends at the opening,
and the tubular member has a smaller cross sectional area perpendicular to the axial
direction between the tip and the opening than a cross sectional area perpendicular
to the axial direction between opening and the rear end.
[0038] The first guide wire extending from the tip and the second guide wire extending may
from the opening form a plane perpendicular to the direction of extrusion of the needle-shaped
tube member from the extrusion aperture.
[0039] The cross sectional area between the tip and the opening may be such that the closer
the distance to the tip, the smaller the area becomes.
[0040] The infusion device may further comprise a balloon attached to an outside portion
of the tubular member, wherein one of the at least three lumens is a balloon lumen
for conducting fluid for expanding the balloon, wherein a plane that includes the
central axes of the first guide wire lumen and the second guide wire lumen, and a
plane that includes the central axes of the needle-shaped tube member lumen and the
balloon lumen, are disposed perpendicular to one another.
[0041] A center of the extrusion aperture may be disposed on the plane that includes the
central axes of the needle-shaped tube member lumen and the balloon lumen.
[0042] In the present invention, any element used in an embodiment can interchangeably be
used in another embodiment as long as it is feasible.
[0043] For purposes of summarizing the invention and the advantages achieved over the related
art, certain objects and advantages of the invention have been described above. Of
course, it is to be understood that not necessarily all such objects or advantages
may be achieved in accordance with any particular embodiment of the invention. Thus,
for example, those skilled in the art will recognize that the invention may be embodied
or carried out in a manner that achieves or optimizes one advantage or group of advantages
as taught herein without necessarily achieving other objects or advantages as may
be taught or suggested herein.
[0044] Further aspects, features and advantages of this invention will become apparent from
the detailed description of the preferred embodiments which follow.
Brief Description of the Drawings
[0045] These and other features of this invention will now be described with reference to
the drawings of preferred embodiments which are intended to illustrate and not to
limit the invention.
[0046] FIG. 1 is a plan view that schematically shows an example of a reagent infusion catheter
having a structure according to the present invention.
[0047] FIG. 2 is a diagram showing a magnification of a section taken along line II-II in
FIG. 1.
[0048] FIG. 3 is a diagram that schematically represents the structure of the reagent infusion
catheter, showing the positions of the central axes of a needle-shaped tube member
and first and second guide wires that have been inserted into the catheter member
of the infusion catheter shown in FIG. 1.
[0049] FIG. 4 is a diagram showing a partial magnification of the infusion catheter shown
in FIG. 1, and includes partially notched representations.
[0050] FIG. 5 is a diagram showing a magnification of a section taken along line V-V in
FIG. 1.
[0051] FIG. 6 is a diagram showing an example of how a predetermined reagent is infused
into a lesion portion of cardiac muscle using the infusion catheter shown in FIG.
1, and shows a state where the first guide wire and the second guide wire have been
inserted into a primary blood vessel and a branch blood vessel on the surface of the
cardiac muscle.
[0052] FIG. 7 is a diagram showing another example of how a predetermined reagent is infused
into a lesion portion of cardiac muscle using the infusion catheter shown in FIG.
1, and shows a state where the needle portion has penetrated the cardiac muscle.
[0053] FIG. 8 is a diagram that corresponds to FIG. 2 and shows another example of an infusion
catheter having a structure according to the present invention.
[0054] FIG. 9 is a diagram that corresponds to FIG. 2 and shows yet another example of an
infusion catheter having a structure according to the present invention.
[0055] FIG. 10 is a diagram that corresponds to FIG. 2 and shows a further example of an
infusion catheter having a structure according to the present invention.
[0056] FIG. 11 is a diagram that corresponds to FIG. 2 and shows a yet further example of
an infusion catheter having a structure according to the present invention.
[0057] FIG. 12 is a diagram that corresponds to FIG. 2 and shows another example of an infusion
catheter having a structure according to the present invention.
Detailed Description of the Preferred Embodiment
[0058] To make the present invention more readily apparent, configurations of infusion devices
according to embodiments of the present invention are described in detail below with
reference to the drawings. However, the present invention should not be limited to
these embodiments.
[0059] First, FIG. 1 and FIG. 2 schematically show a front view and a vertical section,
respectively, of an infusion catheter that is employed to infuse a reagent to a lesion
portion in cardiac muscle as one embodiment of the infusion device having the structure
according to the present invention. In FIGS. 1 and 2, reference numeral 10 denotes
a catheter member made of an elongate tubular member serving as the tubular member,
into which a needle-shaped tube member 12 whose tip portion is a sharp needle portion
11, a first guide wire 14, and a second guide wire 16 each are inserted in such a
manner as to allow movement thereof in the axial direction.
[0060] More specifically, the catheter member 10 has a length and a thickness over its entire
length that permits it to be inserted into a blood vessel extending from the femoral
area or the wrist area of a human body to the heart. Further, the catheter member
10 includes a pliable stainless steel wire buried sandwiched between cylindrical inner
and outer layers each made of a predetermined resin layer. Thus, the catheter member
10 is provided with a good balance of sufficient hardness and flexibility that allows
it to be smoothly inserted into winding blood vessels. It should be noted that there
are no particular limitations regarding the materials providing such a catheter member
10, and in addition to the above-mentioned materials, it is also possible to suitably
adopt materials having a desired elasticity, including synthetic resin materials such
as polyamide, super elastic metal alloy materials such as Ni-Ti alloys, and metallic
materials such as stainless steel.
[0061] Additionally, first through fourth lumens 18a to 18d extending contiguously in the
lengthwise direction are provided independent of one another within the catheter member
10.
[0062] Of the four lumens 18a to 18d, the first and second lumens 18a and 18b have an identical
diameter that is smaller than that of the third lumen 18c, whose lumen diameter is
the largest, and larger than that of the fourth lumen 18d, whose lumen diameter is
the smallest, and both are disposed such that the central axis P
0 of the catheter member 10 is positioned on a plane α (indicated by the long-short
dashed line in FIG. 2) that includes their central axes P
1 and P
2. The third lumen 18c is disposed such that its central axis P
3 matches the central axis P
0 of the catheter member 10, and is centrally positioned between the first lumen 18a
and the second lumen 18b. Furthermore, the fourth lumen 18d is disposed at a position
where a plane β including its central axis P
4 and the central axis P
3 of the third lumen 18c (shown by a long-short dashed line in FIG. 2) is perpendicular
to the plane α that includes the central axes P
1 and P
2 of the first lumen 18a and the second lumen 18b.
[0063] The catheter member 10 including the four lumens 18a to 18d internally also has a
tip opening 20 that opens in the axial direction in the tip of the end portion on
the front side in the direction that the catheter member 10 is inserted into a blood
vessel (the right side in FIG. 1). Moreover, an extrusion aperture 22 passing through
the catheter wall and opening laterally is provided at a site slightly rearward of
the tip in the front end portion of the catheter member 10. The catheter member 10
is further provided with a lateral aperture 24 that passes through the catheter wall
at a site slightly more rearward the site where the extrusion aperture 22 is formed
in the front end portion of the catheter member 10.
[0064] As is clear from FIG. 2 and FIG. 3, which is discussed later, of the three aperture
portions 20, 22, and 24 that are provided in the front end portion of the catheter
member 10, the tip opening 20 and the lateral aperture 24 are each disposed such that
their center points O
1 and O
2 are positioned on the plane α that includes the central axes P
1 and P
2 of the first lumen 18a and the second lumen 18b. On the other hand, the extrusion
aperture 22 is disposed such that its center point O
3 is positioned on the plane β, which includes the central axis P
0 of the catheter member 10 and is perpendicular to the plane α. Thus, here the lateral
aperture 24 is provided in the direction perpendicular to the direction in which the
tip opening 20 and the extrusion aperture 22 are provided.
[0065] In this manner, the tip opening 20 provided in the front end portion of the catheter
member 10 is in communication with the first lumen 18a. Moreover, the lateral aperture
24 is in communication with the second lumen 18b, and the extrusion aperture 22 is
in communication with the third lumen 18c. Thus, at the front end portion of the catheter
member 10 the first lumen 18a opens toward the front side in the axial direction (to
the right in FIG. 1) via the tip opening 20. Also, the second lumen 18b opens laterally
at a right angle to the direction in which the first lumen 18a is provided (in FIG.
1, the direction perpendicular to the paper plane) via the lateral aperture 24. Further,
the third lumen 18c opens in the direction perpendicular to both the direction in
which the first lumen 18a is open or the direction in which the second lumen 18b is
open (downward in FIG. 1) via the extrusion aperture 22.
[0066] On the other hand, three connectors 28, 30, and 32 are attached to the end portion
on the rear side in which the catheter member 10 is inserted into a blood vessel (the
left side in FIG. 1) via a branching socket 26 that branches the catheter member 10
into three. Additionally, an insertion opening 34 that passes through the wall of
the catheter member 10 and is provided in the direction opposite the direction in
which the lateral aperture 24 is provided with respect to in the radial direction
of the catheter member 10 is formed a predetermined distance in front of the site
where the branching socket 26 is provided in the rear end portion of the catheter
member 10.
[0067] Then, the three connectors 28 to 32 are each brought into communication with the
second through fourth lumens 18b to 18d, respectively, provided within the catheter
member 10. Also, the insertion aperture 34 is brought into communication with the
first lumen 18a. Thus, in the rear end portion of the catheter member 10 in the direction
in which the catheter member 10 is inserted into a blood vessel, the first lumen 18a
opens outward via the insertion aperture 34, whereas the second, third, and fourth
lumens 18b to 18d open outward through the openings of the three connectors 28 to
32.
[0068] Next, as discussed above, here the needle-shaped tube member 12 and the first and
second guide wires 14 and 16 are each inserted into the catheter member 10 such that
they can move axially. The first guide wire 14 is inserted into the first lumen 18a
provided within the catheter member 10 via the insertion aperture 34, which is provided
in the wall of the rear end portion of the catheter member 10. On the other hand,
the second guide wire 16 is inserted into the second lumen 18b provided within the
catheter member 10 via the opening (rear end opening) of the connector 28, which is
attached to the rear end portion of the catheter member 10. Further, the needle-shaped
tube member 12 is inserted into the third lumen 18c provided within the catheter member
10 via the opening of the connector 30, which is attached to the rear end portion
of the catheter member 10.
[0069] Consequently, as is clear from FIG. 1 and FIG. 3, which illustrates the position
of the central axes of the needle-shaped tube member 12 and the guide wires 14 and
16, by moving the first guide wire 14 axially forward within the first lumen 18a it
can be extended axially forward from inside the first lumen 18a on the plane α through
the tip opening 20 of the front end portion of the catheter member 10. Also, by moving
the second guide wire 16 axially forward within the second lumen 18b it can be extended
laterally with respect to the axial direction from inside the second lumen 18b on
the plane α through the lateral aperture 24 of the front end portion of the catheter
member 10. Furthermore, by moving the needle-shaped tube member 12 axially forward
within the third lumen 18c, the needle portion 11 of its tip can be extruded outward
on the plane β, which perpendicularly intersects the plane α, through the extrusion
aperture 22 from inside the third lumen 18c in the direction perpendicular to both
the direction in which the first guide wire 14 is extended and the direction in which
the second guide wire 16 is extended. It can be understood from this description that
in the present embodiment the first lumen 18a and the second lumen 18b constitute
the first guide wire lumen and the second guide wire lumen, respectively, and the
third lumen 18c constitutes the needle-shaped tube member lumen.
[0070] As can be understood from FIGS. 2 to 4, the needle-shaped tube member 12 that is
inserted into the third lumen 18c is made of a narrow tube that is overall pliable.
Also, the needle-shaped tube member 12, excluding the needle portion 11 provided in
its tip, is constituted by a reagent conduction duct portion 36 made of a narrow tube
that is longer than the catheter member 10 and that has a diameter of about 0.4 mm.
That is, the needle-shaped tube member 12 is a single unit constituted by the needle
portion 11 and the reagent conduction duct portion 36.
[0071] The reagent conduction duct portion 36 of the needle-shaped tube member 12 is for
example made of a pliable synthetic resin material such as polytetrafluoroethylene
or polyimide. On the other hand, the needle portion 11 is made of an elastic material
such as a super elastic alloy material such as an Ni-Ti alloy or a metallic material
such as stainless steel. The reagent conduction duct portion 36 of the needle-shaped
tube member 12 is connected to a syringe 38 serving as a reagent supply device for
supplying a predetermined reagent that is attached via the connector 30.
[0072] Thus, the needle-shaped tube member 12 is provided with sufficient flexibility and
elasticity and can be smoothly inserted into and moved axially within the third lumen
18c of the catheter member 10 which has been inserted into and follows curved and
winding blood vessels. Also, by moving the needle-shaped tube member 12 axially forward
within the third lumen 18c, the needle portion 11 can be extruded to the outside through
the extrusion aperture 22 of the catheter member 10 made to penetrate cardiac muscle.
Moreover, a reagent, including cells or growth factors such as bFGF (basic Fibroblast
Growth Factor), VEGF (Vascular Endothelial Growth Factor), HGF (Hepatocyte Growth
Factor) or the like, for regenerating nearly or substantially dead cardiac muscle
can be introduced into the reagent conduction duct portion 36 through the syringe
38 and ejected to the outside from the opening of the needle portion 11 of its tip.
[0073] As shown in FIG. 4, here the inner circumferential surface of the front end portion
of the third lumen 18c that includes the opening periphery portion of the extrusion
aperture 22 serves as a guide surface 40 that is constituted by a convex curved surface
that curves axially forward in the direction of the opening of the extrusion aperture
22. The needle portion 11 of the needle-shaped tube member 12 also has a curved shape
that corresponds to the curved shape of the guide surface 40. Thus, the needle portion
11 is slid along the guide surface 40 in conjunction with axially forward movement
of the needle-shaped tube member 12, and due to the guide surface 40, is smoothly
guided toward the extrusion aperture 22.
[0074] It should be noted that the curved shapes of the guide surface 40 and the needle
portion 11 can be suitably determined by taking account of the rigidity of the needle
portion 11, for example. Also, there are no particular limitations regarding the size
of the radius of curvature of the sites of curvature in the guide surface 40 or the
needle portion 11. However, it is preferable that the extrusion angle θ at the point
of contact between the guide surface 40 and the needle portion 11 is 45° or larger
where the curved shape of the guide surface 40 and the curved shape of the needle
portion 11 are combined while the needle portion 11 is extruded from the extrusion
aperture 22.
[0075] Thus, as shown in FIG. 4, when the needle portion 11 has been adequately extruded
from the extrusion aperture 22, the tip area of the needle portion 11 approaches the
extrusion aperture 22 side so that it is easy to identify the position of the needle
portion 11 when extruded. Moreover, it is possible to position the needle portion
11 such that the tangent m of the needle portion 11 is perpendicular to the central
axis P
0 of the catheter member 10 and the central axis P
3 of the third lumen 18c into which the needle-shaped tube member 12 is inserted, at
a position closer to the extrusion aperture 22. Consequently, the component force
of the direction in which the needle-shaped tube member 12 is advanced toward cardiac
muscle (of the two vectors Vv and Vh shown in FIG. 3, the size of the vector Vv perpendicular
to the central axis P
3 of the third lumen 18c) becomes large, and thus the needle-shaped tube member 12
can be more smoothly advanced into cardiac muscle.
[0076] Additionally, here the tip surface of the needle portion 11; that is, an open end
surface 41 in the opening of the needle portion 11, is provided as a slanted surface
that slants in the direction in which the extrusion aperture 22 is provided toward
the front of the catheter member 10, that is, as shown in FIG. 4, it is provided as
a slanted surface in which the lower side of the needle portion 11 is slanted.
[0077] A balloon 42 is provided between the areas where the extrusion aperture 22 and the
lateral aperture 24 are formed in the front end portion of the catheter member 10.
The balloon 42 is made of a pliable synthetic resin material and has a well-known
structure in which a fluid such as physiological saline solution can be introduced
therein to expand the balloon 42 in the direction in which the extrusion aperture
22 is provided, and by discharging this fluid, the balloon can be shrunk from this
expanded state. The fourth lumen 18d opens toward the interior of the balloon 42.
Also, as is clear from FIG. 1, a syringe 44 serving as a fluid supply device that
supplies fluid for expanding the balloon 42 is connected to the connector 32, which
is attached to the rear end portion of the catheter member 10 and in communication
with fourth lumen 18d. It is clear from this description that in the present embodiment,
the fourth lumen 18d constitutes the balloon lumen.
[0078] It should be noted that in FIGS. 1 and 4 that the reference numeral 46 denotes a
marker tube that has been formed using a radiopaque material such as gold, platinum,
a platinum-rhodium alloy, or the like. An open end face on one side in the axial direction
of the marker tube 46 is a slanted face, and a longest site and a shortest site of
axial length are formed in its cylindrical wall portion. The marker tube 46 is fastened
as a sleeve to the catheter member 10, with either the longest site or the shortest
site of its cylindrical wall portion corresponding to the position of the extrusion
aperture 22 formed in the catheter member 10. The tip of the marker tube 46 substantially
matches the tangent m of the needle-shaped tube member 12 (needle portion 11) when
the needle-shaped tube member 12 has been extruded. Thus, when the catheter member
10 has been inserted into a blood vessel, the position of the extrusion aperture 22
and the position of the tip of the needle-shaped tube member 12 can be easily ascertained
by passing X-rays through the tip portion, the longest site, and the shortest site
of the cylindrical wall portion of the marker tube 46. It should be noted that in
the present embodiment, the shortest site of the cylindrical wall portion of the marker
tube 46 is positioned on the extrusion aperture 22 side as shown in FIG. 4. It is
also possible to attach the marker tube 46 by burying it in the catheter member 10.
[0079] Incidentally, with the infusion catheter of the present embodiment having the above
configuration, in particular the catheter member 10 internally provided with the four
lumens 18a to 18d, these being the first through third lumens 18a to 18c in which
the first and second guide wires 14 and 16 and the needle-shaped tube member 12 are
inserted and the fourth lumen 18d for introducing fluid for expanding the balloon
42, has a unique construction that is not found in conventional devices.
[0080] That is, FIG. 2 shows the cross sectional shape perpendicular to the axial direction
at the rear section of the catheter member 10 inside which the first through fourth
lumens 18a to 18d are provided. Also, FIG. 5 shows the cross sectional shape (transverse
cross section) perpendicular to the axial direction at the front section of the catheter
member 10 in which the first lumen 18a and the third and fourth lumens 18c and 18d
are provided. These two cross sectional shapes are substantially triangular shapes
that are different in size.
[0081] More specifically, as shown in FIG. 2, a rear section of the catheter member 10,
or in other words, a site more rearward than the site where the lateral aperture 24
is formed in the catheter member 10, in transverse cross section has three convex
curved corner portions 48, 50, and 52 respectively positioned corresponding to the
apexes Q
1, Q
2, and Q
4 of a triangle A (shown by a long-short dashed line in FIG. 2) that has been formed
with the central axes (center points) P
1, P
2, and P
4 of the first lumen 18a, the second lumen 18b, and the fourth lumen 18d serving as
its apexes, and has three lateral faces 54, 56, and 58 positioned corresponding to
the three bases R
1, R
2, and R
4 of this triangle A. Of the three convex curved corner portions 48, 50, and 52, adjacent
portions are connected by the three lateral faces 54, 56, and 58.
[0082] Thus in the infusion catheter of the present embodiment, the outer circumferential
surface shape of the rear section of the catheter member 10 is substantially triangular
with rounded corner portions. That is, the transverse profile of the rear section
of the catheter member 10 (the sectional shape perpendicular to the axial direction)
is substantially the shape of a triangle formed by recessing three portions of an
annular outer circumference (shown by a long-short dashed line in FIG. 2), whose center
is the central axis P
0 and which connects the convex curved corner portions 48, 50, and 52, radially inward.
[0083] Accordingly, the lateral cross sectional area of the rear section of the catheter
member 10 is smaller than the lateral cross sectional area of conventional catheters
having an annular transverse profile. The three lateral faces 54, 56, and 58 positioned
corresponding to the three bases R
1, R
2, and R
4 of the transverse triangular provide in the rear section of the catheter member 10
are provided as recessed portions formed extending contiguously over the entire length
in the axial direction in the outer circumferential surface of the rear end section
of the catheter member 10.
[0084] It should be noted that in the rear section of the catheter member 10 having such
an outer circumferential shape, the distance X
1 from the tip of the convex curved corner portion 52 positioned on the side on which
the extrusion aperture 22 is formed to the lateral face 58 in opposition thereto,
which is the largest width in the direction of extrusion of the needle-shaped tube
member 12 (down in FIG. 2), is approximately 1.5 mm. Also, the distance Y
1 between the tips of the two convex curved corner portions 48 and 50 at either end
of the lateral face 58, which is the largest width in the direction perpendicular
to the direction of extrusion of the needle-shaped tube member 12 (the left to right
direction in FIG. 2), is approximately 2.0 mm. Thus, the width of the rear end portion
of the catheter member 10 is larger than the distance in the extrusion direction of
the needle-shape tube member 12. This makes it possible to easily bend the catheter
member 10 in the direction of extrusion of the needle-shaped tube member 12.
[0085] Moreover, in the rear section of the catheter member 10, of the three lateral faces
54, 56, and 58, the lateral face 58 positioned corresponding to the base R
4 that links the two apexes Q
1 and Q
2 corresponding to the central axes P
1 and P
2 of the first lumen 18a and the second lumen 18b, respectively, that is, the lateral
face 58 extending perpendicular to the direction in which the needle-shaped tube member
12 is extruded from the extrusion aperture 22 and in opposition to the convex curved
corner portion 52, which is positioned on the side on which the extrusion aperture
22 is formed, is a curved surface whose curvature is small. Thus, when the needle-shaped
tube member 12 penetrates cardiac muscle, the reaction force causes the curved lateral
face 58 of the catheter member 10 to come into contact the inner wall surface of the
blood vessel over the largest area. Also, the two lateral faces 54 and 56 other than
the lateral face 58, which is a curved surface, both have flat surfaces. Thus, the
lateral cross sectional area of the rear section of the catheter member 10 is made
as small as possible.
[0086] On the other hand, as shown in FIG. 5, the second lumen 18b is not formed in the
front section of the catheter member 10, or in other words, the site more forward
than the site where the lateral aperture 24 is formed in the catheter member 10. Thus,
the front section of the catheter member 10, in cross section, has three convex curved
corner portions 60, 62, and 64 respectively positioned corresponding to the apexes
Q
1, Q
3, and Q
4 of a triangle B (shown by a long-short dashed line in FIG. 5) whose apexes are the
central axes (center points) P
1, P
3, and P
4 of the first lumen 18a, the third lumen 18c, and the fourth lumen 18d, and has three
lateral faces 66, 68, and 70 positioned corresponding to the three bases R
1, R
3, and R
4 of the triangle B. Of the three convex curved corner portions 60, 62, and 64, adjacent
portions are connected by the three lateral faces 66, 68, and 70.
[0087] Thus, the outer circumferential surface shape of the front section of the catheter
member 10 is substantially the shape of a triangle whose corner portions have been
rounded. Further, the outer circumference shape of the front section of the catheter
member 10 is smaller than that of the rear section of the catheter member 10. In other
words, the transverse profile of the front section of the catheter member 10 is substantially
the shape of a triangle, in which an annular outer circumference (shown by a long-short
dashed line in FIG. 5) whose center is the central axis P
0 and which connects the two convex curved corner portions 60 and 64, is formed significantly
more recessed than the rear section of the catheter member 10.
[0088] Accordingly, the lateral cross sectional area of the front section of the catheter
member 10 is even smaller than the lateral sectional area of the rear section. Thus,
the geometrical moment of inertia in the front section of the catheter member 10 is
lowered, thereby increasing the flexibility. In the front section of the catheter
member 10, the three lateral faces 66, 68, and 70 positioned corresponding to the
three bases R
1, R
3, and R
4 of the transverse triangular shape are provided as recessed portions formed extending
contiguously over the entire length in the axial direction in the outer circumferential
surface of the front section of the catheter member 10. That is, the lateral face
66 is smoothly connected to the lateral face 54. Also, the lateral face 68 and the
lateral face 56 in practice are the same lateral face. Moreover, the lateral face
70 is connected to the lateral face 58.
[0089] It should be noted that in the front section of the catheter member 10 having such
an outer circumferential shape, the distance X
2 from the tip of the convex curved corner portion 64 positioned on the side on which
the extrusion aperture 22 is formed to the lateral face 70 in opposition thereto,
which has the largest width in the direction of extrusion of the needle-shaped tube
member 12, is approximately 1.5 mm. Also, the distance Y
2 between the tips of the convex curved corner portions 60 and 62 at either end of
the lateral face 70, which is the largest width in the direction perpendicular to
the direction of extrusion of the needle-shaped tube member 12, also is approximately
1.5 mm.
[0090] Moreover, in the front section of the catheter member 10, of the three lateral faces
66, 68, and 70, the lateral face 70 positioned corresponding to the base R
4 that links the two apexes Q
1 and Q
3 that correspond to the central axes P
1 and P
3 of the first lumen 18a and the third lumen 18c, respectively, that is, the lateral
face 70 in opposition to the convex curved corner portion 64 in which the extrusion
aperture 22 is formed and extending perpendicular to the direction in which the needle-shaped
tube member 12 is extruded from the extrusion aperture 22, is a curved surface whose
curvature is small. Thus, when the needle-shaped tube member 12 penetrates cardiac
muscle, the reaction force causes the curved lateral face 70 of the catheter member
10 to come into contact with the inner wall surface of the blood vessel over the largest
area. Also, the two lateral faces 66 and 68 other than the lateral face 70, which
is a curved surface, both have flat surfaces. Thus, the lateral cross sectional area
of the front section of the catheter member 10 is made as small as possible.
[0091] A method for infusing a predetermined reagent into a lesion portion such as nearly
or substantially necrotic cardiac muscle using the infusion catheter of the present
embodiment with the above structure is described next.
[0092] When performing a reagent infusion treatment using this infusion catheter, first,
as shown in FIG. 6, the first guide wire 14 is inserted into a primary blood vessel
74 on the surface of cardiac muscle 72. The second guide wire 16, in contrast, is
inserted into a branch blood vessel 76 on the surface of the cardiac muscle 72 that
has branched from the primary blood vessel 74. It should be noted that in general
the first and the second guide wires 14 and 16 are inserted into the primary blood
vessel 74 and the branch blood vessel 76 by hand.
[0093] Next, the catheter member 10 is inserted into the primary blood vessel 74 on the
surface of the cardiac muscle 72 along the first guide wire 14. While the catheter
member 10 is inserted into the primary blood vessel 74, the position of the marker
tube 46 provided on the outside of the front end portion in the direction of insertion
of the catheter member 10 on a monitor or the like is confirmed using radiation. That
is, once the marker tube 46 has arrived at a predetermined area of the primary blood
vessel 74 by threading the catheter member 10 through the primary blood vessel 74,
threading of the catheter member 10 is temporarily halted. Then, after confirming
the position of the shortest site or the longest site of the marker tube 46, the catheter
member 10 is rotated about its axis while fine tuning its axial position within the
primary blood vessel 74 in order to position the extrusion aperture 22 such that it
opens toward the lesion portion at a predetermined position of the lesion portion
of the cardiac muscle 72 to which the reagent is to be infused.
[0094] It should be noted that as discussed above, in the infusion catheter of the present
embodiment the section to the rear of the spot where the lateral aperture 24 is formed
and the section in front of this spot in the catheter member 10 both have a substantially
triangular transverse profile, and thus the lateral cross sectional area of these
sections is effectively small. It is accordingly easy to insert the catheter member
10 into the primary blood vessel 74.
[0095] Moreover, the lateral cross sectional area of the front section is smaller than the
lateral cross sectional area of the rear section of the catheter member 10, and this
increases the flexibility of the front section. Thus, damage to the inner wall surface
of the primary blood vessel 74 when inserting the catheter member 10 into the primary
blood vessel 74 can be effectively prevented.
[0096] Furthermore, the rear section of the catheter member 10 has the lateral face 58,
which is a curved surface whose curvature is small, and the two flat lateral faces
54 and 56. On the other hand, the front section of the catheter member 10 also has
the lateral face 70, which is a curved surface whose curvature is small, and the two
flat lateral faces 66 and 68. For that reason, when the catheter member 10 is inserted
into the primary blood vessel 74, a gap is formed between the lateral faces 54, 56,
58, 66, 68, and 70 and the inner wall surface of the primary blood vessel 74. Thus,
blood can reliably flow through the gap formed between the lateral faces 54, 56, 58,
66, 68, and 70 and the inner wall surface of the primary blood vessel 74 when the
catheter member 10 has been inserted into the primary blood vessel 74.
[0097] Next, as shown in FIG. 7, once the catheter member 10 has been positioned at the
foregoing predetermined position within the primary blood vessel 74, physiological
saline solution or the like is introduced into the fourth lumen 18d within the catheter
member 10 from the syringe 44, expanding the balloon 42 toward the direction in which
the extrusion aperture 22 opens. By doing this the catheter member 10 is fixedly retained
within the primary blood vessel 74 at the lesion portion of the cardiac muscle 72
to which the reagent is to be infused. It should be noted that at this time the gap
between the lateral faces 54, 56, 58, 66, 68, and 70 and the inner wall surface of
the primary blood vessel 74 is secured. Thus, even when the balloon 42 has expanded
it is possible to favorably ensure the flow of blood within the primary blood vessel
74.
[0098] Next, the needle-shaped tube member 12 is moved within the third lumen 18c forward
in the direction in which the catheter member 10 is inserted into the primary blood
vessel 74. When the needle portion 11 of the tip of the needle-shaped tube member
12 has arrived at the front end portion within the third lumen 18c, the needle portion
11 is slid along the guide surface 40 provided in the inner circumference portion
of the front end portion of the third lumen 18c while it is smoothly advanced toward
the extrusion aperture 22, as shown by the long-short dashed line in FIG. 7. Then,
by further moving the needle-shaped tube member 12 forward, the needle portion 11
is extruded through the extrusion aperture 22 as shown by the solid line in FIG. 7.
The operation of extruding the needle portion 11 by moving the needle-shaped tube
member 12 is carried out manually or using a screw mechanism, for example, that is
known to the public.
[0099] It should be noted that as mentioned above, in the infusion catheter of the present
embodiment, the needle portion 11 of the needle-shaped tube member 12 is extruded
from the extrusion aperture 22 in a direction that is substantially perpendicular
to the direction in which the first guide wire 14 and the second guide wire 16 are
extended from the tip opening 20 and the lateral aperture 24, respectively, of the
catheter member 10. Also, here the first guide wire 14 and the second guide wire 16
that have been extended through the tip opening 20 and the lateral aperture 24, respectively,
of the catheter member 10 are inserted into the primary blood vessel 74 and the branch
blood vessel 76, respectively, running over the surface of the cardiac muscle 72.
Thus, the plane formed by the first and second guide wires 14 and 16 is substantially
approximate to the surface of the cardiac muscle 72.
[0100] Consequently, through the operation discussed above, the needle portion 11 of the
needle-shaped tube member 12 that has been extruded from the extrusion aperture 22
of the catheter member 10 is extruded substantially perpendicularly to the surface
of the cardiac muscle 72. Moreover, the needle portion 11, as discussed above, has
a curved shape that curves in the direction of extrusion from the extrusion aperture
22 in the movement direction of the needle-shaped tube member 12, and thus when it
has been extruded from the extrusion aperture 22, it is disposed such that the tangent
m of its tip region is perpendicular to the central axis P
0 of the catheter member 10. It should be noted that strictly speaking, "substantially
perpendicular" here is used taking into account that there may be cases in which the
needle portion 11 is not extruded perpendicular to the surface of the cardiac muscle
72 because, in practice, the cardiac muscle 72 has a complex shape.
[0101] Consequently, due to this operation, the needle portion 11 of the needle-shaped tube
member 12 that has been extruded from the extrusion aperture 22 of the catheter member
10 is passed through a blood vessel wall 78 of the primary blood vessel 72 and penetrates
a predetermined spot of a lesion portion of the cardiac muscle 72. Then, as the needle-shaped
tube member 12 is moved forward within the catheter member 10, the needle portion
11 is advanced substantially perpendicular with respect to the surface of the cardiac
muscle 72 until reaching a predetermined depth of the lesion portion.
[0102] When advancing the needle portion 11 into the lesion portion, most of the reaction
force with respect to advancing the needle portion 11 into the cardiac muscle 72 in
the direction opposite the direction in which the needle portion 11 is advancing,
that is, in the direction perpendicular to the surface of the cardiac muscle 72, is
applied to the catheter member 10 via the needle portion 11. However, here the first
guide wire 14 and the second guide wire 16 are inserted into and positioned in the
primary blood vessel 74 and the branch blood vessel 76 on the surface of the cardiac
muscle 72, and thus this reaction force is divided between the first guide wire 14
and the second guide wire 16 and can be adequately and reliably received. Consequently,
due to the present operation, the needle portion 11 can be very smoothly and reliably
advanced to a predetermined depth of the lesion portion of the cardiac muscle 72.
[0103] It should be noted that, as discussed above, the rear section of the catheter member
10 is more easily bent in the direction of extrusion of the needle-shaped tube member
12 than in the direction perpendicular to this direction. For that reason, when inserting
the catheter member 10 into the primary blood vessel 74, the catheter member 10 is
easily bent following the surface of the cardiac muscle 72, making insertion of the
catheter member 10 into the primary blood vessel 74 easy. Also, when the needle portion
11 has penetrated the lesion portion of the cardiac muscle 72, the rear section of
the catheter member 10 is easily bent in the extrusion direction of the needle-shaped
tube member 12, allowing some of the rear section and the area in front of that portion
of the catheter member 10 to be brought into contact with the inner wall surface of
the primary blood vessel 74 at the lateral faces 58 and 70, which are curved large-area
portions, on the side opposite the extrusion direction of the needle-shaped tube member
12.
[0104] Consequently, when the needle portion 11 of the needle-shaped tube member 12 penetrates
the lesion portion of the cardiac muscle 72 and is advanced through this operation,
that reaction force is favorably and efficiently received by the two lateral faces
58 and 70, which are curved surfaces, of the catheter member 10 without damaging the
inner wall surface of the primary blood vessel 74.
[0105] Next, movement of needle-shaped tube member 12 is ended once the needle portion 11
has been advanced up to a predetermined depth position of the lesion portion of the
cardiac muscle 72. A reagent including cells or growth factor, for example, aimed
at regenerating the cardiac muscle 72 is then introduced into the inner lumen of the
needle-shaped tube member 12 from the syringe 44 that is connected to the connector
32 at the proximal side of the needle-shaped tube member 12. This reagent is then
infused into the lesion portion of the cardiac muscle 72 by ejecting it from the tip
opening of the needle portion 11.
[0106] Once the reagent has been infused to an area of the lesion portion of the cardiac
muscle 72, the needle-shaped tube member 12 is retreated within the catheter member
10, drawing the needle portion 11 into the catheter member 10. This operation of infusing
a reagent to a lesion portion of the cardiac muscle 72 is repeated a plurality of
times at other locations, and by doing so the reagent is infused to a plurality of
areas of the lesion portion of the cardiac muscle 72.
[0107] In this way, the infusion catheter of the present embodiment has a catheter member
10 whose outer circumferential shape is substantially triangular with rounded corner
portions, and as such the lateral cross sectional area of the catheter member 10 is
suitably small. Thus, the catheter member 10 can be more smoothly and easily inserted
into the primary blood vessel 74 than if a conventional infusion catheter, for example,
whose a catheter member 10 has an annular transverse profile, is inserted into the
primary blood vessel 74.
[0108] Moreover, with this infusion catheter, when the catheter member 10 has been inserted
into the primary blood vessel 74, a gap is formed between the three lateral faces
54, 56, and 58 of the rear section thereof and the inner wall surface of the primary
blood vessel 74 and between the three lateral faces 66, 68, and 70 of the front section
thereof and the lateral wall surface of the primary blood vessel 74, allowing the
flow of blood to be favorably secured. Further, the front section of the catheter
member 10 has a smaller lateral cross sectional area than its rear section. This allows
the flow of blood within the primary blood vessel 74 to be more effectively secured
when the catheter member 10 has been inserted. Consequently, the task of infusing
a predetermined reagent into a lesion portion of the cardiac muscle 72 can be carried
out more safely.
[0109] With the infusion catheter of the present embodiment, the needle portion 11 extruded
from the extrusion aperture 22 of the catheter member 10 can be reliably penetrated
into a predetermined location of the lesion portion of the cardiac muscle 72. Moreover,
most of the reaction force that is generated by the needle portion 11penetrating the
cardiac muscle 72 is adequately and reliably received by the first guide wire 14 and
the second guide wire 16, which are inserted into the primary blood vessel 74 and
the branch blood vessel 76 on the surface of the cardiac muscle 72, and thus the needle
portion 11 can be very smoothly and reliably advanced up to a predetermined depth
position of the lesion portion of the cardiac muscle 72.
[0110] Thus, if the infusion catheter of the present embodiment described above is used,
then the needle portion 11 can reliably penetrate the lesion portion at a predetermined
position up to a desired depth, even if the lesion portion of the cardiac muscle 72
is hard. As a result, the effect of treatment or a procedure in which a predetermined
reagent for regenerating the cardiac muscle 72 is infused into a lesion portion of
the cardiac muscle 72 can be more adequately increased.
[0111] Further, with the infusion catheter of the present embodiment, the first guide wire
14 is inserted into the first lumen 18a from the insertion aperture 34 provided opening
laterally in the rear end portion of the catheter member 10 and extended directly
forward axially through the tip opening 20 of the catheter member 10. Also, the second
guide wire 16 is inserted directly into the second lumen 18b from the opening of the
connector 26 attached to the rear end portion of the catheter member 10, and is extended
laterally through the lateral aperture 24, which is provided opening laterally, in
the front end portion of the catheter member 10.
[0112] Thus, with this infusion catheter, the first guide wire 14 and the second guide wire
16 both are threaded through the catheter member 10 bent or curved at only one position.
Consequently, there is relatively little resistance to sliding the guide wires 14
and 16 through the catheter member 10, and this allows the guide wires 14 and 16 to
be threaded through the catheter member 10 more smoothly.
[0113] Furthermore, with the infusion catheter according to the present embodiment, the
third lumen 18c into which the needle-shaped tube member 12 is inserted and arranged
is disposed such that its central axis P
3 matches the central axis P
0 of the catheter member 10. Thus, the infusion catheter has good overall balance,
and accordingly the task of infusing a reagent to a lesion portion of the cardiac
muscle 72 can be performed more stably.
[0114] Further, with this infusion catheter, the extrusion aperture 22 is arranged in such
a manner that the center point O
3 of the extrusion aperture 22 through which needle portion 11 of the needle-shaped
tube member 12 is extruded is positioned on the plane β, which is perpendicular to
the plane α including the central axis P
3 of the third lumen 18c into which the needle-shaped tube member 12 is inserted and
arranged and the central axis P
0 of the catheter member 10 matching the central axis P
3, and also including the central axes P
1 and P
2 of the first and second lumens 18a and 18b into which the first and second guide
wires 14 and 16 are respectively inserted and arranged. Thus, it provides a favorable
balance in the arrangement of the needle-shape tube member 12 in the catheter member
10 and stability during the operation when extruding the needle portion 11 from the
extrusion aperture 22. As a result, the task of infusing a reagent to a lesion portion
of the cardiac muscle 72 can be performed even more stably and smoothly.
[0115] Further, with the infusion catheter according to the present embodiment, the central
axes P
1 and P
2 of the first and second lumens 18a and 18b into which the first and second guide
wires 14 and 16 are respectively inserted and arranged, the central axis P
3 of the third lumen 18c into which the needle-shaped tube member 12 is inserted and
arranged, and the central axis P
0 of the catheter member 10 are positioned on a single plane α, and the first and second
lumens 18a and 18b are disposed on either side of the third lumen 18c and sandwich
it between them. Thus, the distance between the first lumen 18a and the second lumen
18b is made as large as possible, and this allows the distance between the first guide
wire 14 and the second guide wire 16, which are extended to the outside through the
tip opening 20 and the lateral aperture 24 of the catheter member 10 from the two
lumens 18a and 18b, to be made large also. As a result, most of the reaction force
that is generated when the needle portion 11 is inserted into a lesion portion of
the cardiac muscle 72 can be more adequately and reliably received and stopped by
the first guide wire 14 and the second guide wire 16.
[0116] With this infusion catheter, the fourth lumen 18d for conducting fluid for expanding
the balloon 42 that is provided outside the catheter member 10 is disposed in such
a manner that its central axis P
4 is positioned on the plane β, which includes the central axis P
3 of the third lumen 18c into which the needle-shaped tube member 12 is inserted and
arranged, the central axis P
0 of the catheter member 10, and the center point O
3 of the extrusion aperture 22. This also results in a good overall balance of the
infusion catheter, and thus the task of infusing a reagent to a lesion portion of
the cardiac muscle 72 can be performed more stably.
[0117] Furthermore, in the infusion catheter of the present embodiment, the inner circumferential
surface of the front end portion of the third lumen 18c, into which the needle-shaped
tube member 12 is inserted and arranged, serves as the guide surface 40, which is
a convex curved surface that is curved axially forward in the direction in which the
extrusion aperture 22 is provided, and the needle portion 11 of the needle-shaped
tube member 12 also has a curved shaped that corresponds to the guide surface 40.
For that reason, the needle portion 11 can be smoothly and reliably extruded from
the extrusion aperture 22 in the direction perpendicular to the surface of the cardiac
muscle 72 in conjunction with forward movement of the needle-shaped tube member 12
within the catheter member 10. Due to this structure as well, the task of infusing
a reagent to a lesion portion of the cardiac muscle 72 can be performed even more
stably and smoothly.
[0118] The positions where the first through fourth lumens 18a to 18d provided within the
catheter member 10 are arranged and the outer circumferential shape of the catheter
member 10 are not limited to the example discussed above, however.
[0119] For example, as shown in FIG. 8, it is also possible to dispose the third lumen 18c
such that its central axis P
3 is positioned shifted in the radial direction of the catheter member 10 from the
central axis P
0 of the catheter member 10 toward the side where the extrusion aperture 22 is formed,
and the first and second lumens 18a and 18b are disposed such that the plane α including
their central axes P
1 and P
2 is shifted in the radial direction of the catheter member 10 from the central axis
P
0 of the catheter member 10 toward the side opposite the side where the extrusion aperture
22 is formed.
[0120] In this manner it is possible to adopt a configuration having an outer circumferential
surface shape in which the three lateral faces 54, 56, and 58, which are positioned
corresponding to the bases R
1, R
2, and R
4 of a triangle C (shown by a long-short dashed line in FIG. 8) whose apexes are the
central axes (center points) P
1, P
2, and P
4 of the first and second lumens 18a and 18b thus disposed and the fourth lumen 18d.
[0121] Further, as shown in FIG. 9, it is also possible to dispose the third lumen 18c such
that its central axis P
3 is positioned shifted in the radial direction of the catheter member 10 from the
central axis P
0 of the catheter member 10 toward the side opposite the side where the extrusion aperture
22 is formed, and the first and second lumens 18a and 18b are disposed such that the
plane a including their central axes P
1 and P
2 is shifted in the radial direction of the catheter member 10 from the central axis
P
0 of the catheter member 10 toward the side where the extrusion aperture 22 is formed.
[0122] In this manner it is possible to adopt a configuration having a substantially rectangular
outer circumferential shape provided with four convex curved corner portions 48, 50,
52, and 53 positioned corresponding to the apexes Q
1 to Q
4 of a rectangle D (shown by a long-short dashed line in FIG. 9) whose apexes are the
central axes (center points) P
1 to P
4 of the first through fourth lumens 18a and 18d disposed in this manner, and four
flat lateral faces 54, 56, 58, and 59 that are positioned corresponding to the bases
R
1 to R
4 of the rectangle D and connect the four convex curved corner portions 48, 50, 52,
and 53.
[0123] In the two embodiments having the structures shown in FIG. 8 and FIG. 9, the transverse
profile of the catheter member 10 is smaller than an annular shape (shown by a long-short
dashed line in FIG. 8 and FIG. 9) whose center is the central axis P
0 and whose radius is the apex of the convex curved corner portion farthest from the
central axis P
0. Also, the lateral faces 54, 56, 58, and 59 of the catheter member 10 are provided
as recessed portions extending contiguously over the entire length in the axial direction
in the outer circumferential surface of the catheter member 10. Furthermore, the needle
portion 11 of the needle-shaped tube member 12 can be extruded in the direction perpendicular
to the direction of extrusion of the first guide wire 14 and the second guide wire
16. Consequently, the same operations and effects as in the first embodiment can be
obtained effectively with the second and third embodiments as well.
[0124] Further, as shown in FIG. 10, the third lumen 18c is disposed coaxially with the
catheter member 10, whereas the first lumen 18a is disposed such that its central
axis P
1 is positioned on the side opposite the side on which the center point O
3 of the extrusion aperture 22 is provided, sandwiching the central axis P
3 of the third lumen 18c between them, on a plane β including the central axis P
3 of the third lumen 18c, the central axis P
0 of the catheter member 10, and the center point O
3 of the extrusion aperture 22. Moreover, the second lumen 18b is disposed such that
its central axis P
2 is positioned on a plane α, which includes the central axis P
3 of the third lumen 18c and the central axis P
0 of the catheter member 10 and which is perpendicular to the plane β.
[0125] In this manner it is possible to achieve a configuration having an outer circumferential
shape provided with the three lateral faces 54, 56, and 58, which are positioned corresponding
to the bases R
1, R
2, and R
4 of a triangle E (shown by a long-short dashed line in FIG. 10) whose apexes are the
central axes (center points) P
1, P
2, and P
4 of the first and second lumens 18a and 18b thus disposed and the fourth lumen 18d.
[0126] Further, as shown in FIG. 11, it is also possible to arrange the first, second, and
third lumens 18a to 18c such that their respective central axes (center points) P
1 to P
3 are positioned on a plane β, which includes the central axis P
0 of the catheter member 10 and the center point O
3 of the extrusion aperture 22. Also, the fourth lumen 18d can be disposed at a position
that is different from the positions where it is disposed in the first through third
embodiments.
[0127] In this manner, it is possible to adopt a configuration having an outer circumferential
shape provided with three lateral faces 54, 58, and 59, which are positioned corresponding
to the bases R
1, R
3, and R
4 of a triangle F (shown by a long-short dashed line in FIG. 11) whose apexes are the
central axes (center points) P
1, P
3, and P
4 of the first lumen 18a, the third lumen 18c, and the fourth lumen 18d disposed in
this manner, and in which of these lateral faces, the two lateral faces 58 and 59
are concave curved surfaces.
[0128] In the two embodiments having the structures shown in FIG. 10 and FIG. 11, the transverse
profile of the catheter member 10 is smaller than an annular shape (shown by a long-short
dashed line in FIG. 10 and FIG. 11) whose center is the central axis P
0 and whose radius is the apex of the convex curved corner portion farthest from the
central axis P
0. Also, the lateral faces 54, 56, 58, and 59 of the catheter member 10 are provided
as recessed portions extending contiguously over the entire length in the axial direction
in the outer circumferential surface of the catheter member 10. Thus, the catheter
member 10 can be easily inserted into the primary blood vessel 74, and while inserted
therein, the flow of blood through the primary blood vessel 74 can be favorably secured.
[0129] In these two embodiments the first lumen 18a and the second lumen 18b are displaced
and parallel to one another, and have a deviation d in the radial direction of the
catheter member 10 between the positions where their respective central axes P
1 and P
2 are disposed. This deviation d, however, it is a very short length, and is smaller
than the radius of the catheter member 10. For that reason, there is substantially
no difference in the points of intersection between the extension direction vectors
of the first and second guide wires 14 and 16 inserted and arranged in the first and
second lumens 18a and 18b, respectively, and thus the needle-shaped tube member 12
is substantially extruded in the plane including these direction vectors. Consequently,
this tiny deviation d has hardly any effect.
[0130] Thus, in the fourth and fifth embodiments described above, the needle portion 11
of the needle-shaped tube member 12 can be extruded in a direction that is substantially
perpendicular to the direction in which the first and the second guide wires 14 and
16 are extruded. The same operations and effects as in the first embodiment can therefore
be obtained effectively with the fourth and fifth embodiments as well.
[0131] Specific configurations of the present invention have been described in detail above,
but these are only illustrative examples, and the present invention is in no way restricted
by the foregoing description.
[0132] For example, there is no limitation to the number indicated in the foregoing embodiments
regarding the convex curved corner portions or the lateral faces providing the outer
circumferential surface of the catheter member 10. That is, as shown in FIG. 12, it
is also possible to adopt a configuration in which the outer circumferential surface
is constituted by the two lateral faces of a substantially semi-annular lateral face
80 and a lateral face 82 made of a convex curved surface with small curvature, and
two convex curved corner portions 84 and 86. It is of course also possible to achieve
the catheter member 10 using an outer circumferential shape having five or more lateral
faces or convex curved corner portions.
[0133] As long as concave portions extending axially are formed in the outer circumferential
surface of the catheter member 10 such that the sectional shape of the catheter member
10 perpendicular to its axial direction is a shape in which at least a portion of
the outer circumference of an annular shape has been recessed radially, then the outer
circumferential shape of the catheter member 10 is not absolutely limited to the configurations
that have been provided for illustration.
[0134] Also, it is not absolutely necessary that the recessed portions formed in the outer
circumferential surface of the catheter member 10 are formed extending contiguously
over the entire length of the catheter member 10. Thus, for example, it is of course
also possible to adopt a configuration in which recessed portions are formed intermittently
over the entire length of the outer circumferential surface of the catheter member
10, or a configuration in which, in the catheter member 10, recessed portions are
not provided in the outer circumferential surface of portions that are not inserted
into the body.
[0135] Moreover, it is only necessary that any three of the first through fourth lumens
18a to 18d are formed within the catheter member 10.
[0136] Furthermore, there is nothing preventing the adoption of a shape in which the guide
surface 40 made of a convex curved surface is formed in the inner circumferential
surface of the front end portion of the third lumen 18 but the needle portion 11 is
provided with a straight shape.
[0137] Also, in the above embodiments, the open end surface 41 of the needle portion 11
is a slanted surface that is slanted in the extrusion direction of the needle portion
11 toward the direction in which the needle-shaped tube member 12 moves when the needle
portion 11 is extruded from the extrusion aperture 22 (in FIG. 1, the lower side of
the needle portion 11 is the slanted surface). However, alternatively it is also possible
to provide the open end surface 41 as a slanted surface that is slanted in the extrusion
direction of the needle portion 11 toward the direction that is opposite the direction
in which the needle-shaped tube member 12 is moved when the needle portion 11 is extruded
from the extrusion aperture 22 (in FIG. 1, the upper side of the needle portion 11
is the slanted surface). It should be noted that with the configuration of the present
embodiment (in which the open end surface 41 is a slanted surface on the lower side
of the needle portion 11 in FIG. 1), damage to or destruction of the inner circumferential
surface of the third lumen 18c due to contact with the needle portion 11 when the
needle portion 11 is moved within the third lumen 18c in conjunction with movement
of the needle-shaped tube member 12 can be effectively prevented.
[0138] Furthermore, the balloon 42 that is provided outside the catheter member 10 is not
essential to an embodiment of the present invention, and thus it is possible to omit
the balloon 42. Even if the balloon 42 is provided outside the catheter member 10,
the position where it is arranged is not limited to the foregoing embodiments.
[0139] In the foregoing embodiments, the needle portion 11 of the needle-shaped tube member
12 has a curved shape and the inner circumferential surface of the front end portion
of the third lumen 18c is the guide surface 40, which is a convex curved surface,
but the same effects can be achieved even if the needle portion 11 of the needle-shaped
tube member 12 has a shape where it is extended straight.
[0140] Furthermore, the foregoing embodiments show specific examples in which the present
invention is adopted for an infusion catheter for infusing a reagent to a lesion portion
of cardiac muscle. The present invention, however, can of course also be favorably
adopted in an embodiment for infusion catheters for infusing a reagent into body tissue
other than cardiac muscle and infusion devices that are for infusing a reagent to
lesion portions of cardiac muscle or body tissues other than cardiac muscle but that
do fit within the scope of catheters.
[0141] As can be understood from the above description, the infusion device according to
an embodiment of the present invention can be easily inserted into the body even though
at least three lumens are provided within it. Also, even if the device is inserted
into a blood vessel, the flow of blood within that blood vessel can be reliably ensured.