U.S. patent application number 17/029562 was filed with the patent office on 2021-01-07 for dilator.
This patent application is currently assigned to ASAHI INTECC CO., LTD.. The applicant listed for this patent is ASAHI INTECC CO., LTD.. Invention is credited to Yukihiro FUSEYA, Hideaki MAKI, Akira SAWAI, Daiki TAKAHASHI, Marina TSUZUKU.
Application Number | 20210001097 17/029562 |
Document ID | / |
Family ID | |
Filed Date | 2021-01-07 |
United States Patent
Application |
20210001097 |
Kind Code |
A1 |
FUSEYA; Yukihiro ; et
al. |
January 7, 2021 |
DILATOR
Abstract
The shaft of a dilator has a tapered part whose outer diameter
at a distal end is smaller than at a proximal end, and either a
distal end part and a proximal end part, or a proximal end part
without a distal end part. If only the proximal end part is
provided, the pitch of neighboring sections of a spirally-arranged
protruding portion on the tapered part is larger than that on the
proximal end part. If both the proximal end part and the distal end
part are provided, the pitch of neighboring sections of the
spirally-arranged protruding portion on the tapered part is larger
than those on the distal end part or the proximal end part.
Inventors: |
FUSEYA; Yukihiro; (Seto-shi,
JP) ; MAKI; Hideaki; (Seto-shi, JP) ;
TAKAHASHI; Daiki; (Seto-shi, JP) ; SAWAI; Akira;
(Seto-shi, JP) ; TSUZUKU; Marina; (Seto-shi,
JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
ASAHI INTECC CO., LTD. |
Seto-shi |
|
JP |
|
|
Assignee: |
ASAHI INTECC CO., LTD.
Seto-shi
JP
|
Appl. No.: |
17/029562 |
Filed: |
September 23, 2020 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
PCT/JP2018/035089 |
Sep 21, 2018 |
|
|
|
17029562 |
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Current U.S.
Class: |
1/1 |
International
Class: |
A61M 29/00 20060101
A61M029/00; A61M 25/00 20060101 A61M025/00 |
Foreign Application Data
Date |
Code |
Application Number |
Mar 23, 2018 |
JP |
PCT/JP2018/011673 |
Claims
1. A dilator comprising: a shaft having a hollow shape, the shaft
comprising: a tapered portion having an outer diameter that is
smaller at a distal end of the tapered portion than at a proximal
end of the tapered portion; a proximal end portion that is provided
on a proximal side of the tapered portion and that extends in a
proximal direction; and optionally, a distal end portion that is
provided on a distal side of the tapered portion and that extends
in a distal direction; and a spirally-arranged protruding portion
provided on an outer peripheral surface of the shaft, the
spirally-arranged protruding portion having gaps between adjacent
sections of the spirally-arranged protruding portion along a
longitudinal axis of the shaft, wherein: in a case where the shaft
does not include the distal end portion, a pitch of the adjacent
sections of the spirally-arranged protruding portion provided on
the tapered portion is larger than a pitch of the adjacent sections
of the spirally-arranged protruding portion provided on the
proximal end portion, and in a case where the shaft includes the
distal end portion, the pitch of the adjacent sections of the
spirally-arranged protruding portion provided on the tapered
portion is larger than (i) a pitch of the adjacent sections of the
spirally-arranged protruding portion provided on the distal end
portion or (ii) the pitch of the adjacent sections of the
spirally-arranged protruding portion provided on the proximal end
portion.
2. The dilator according to claim 1, wherein in the case where the
shaft includes the distal end portion, the pitch of the adjacent
sections of the spirally-arranged protruding portion provided on
the tapered portion is larger than both (i) the pitch of the
adjacent sections of the spirally-arranged protruding portion
provided on the distal end portion and (ii) the pitch of the
adjacent sections of the spirally-arranged protruding portion
provided on the proximal end portion.
3. The dilator according to claim 1, wherein the shaft includes a
coil comprising a wire wound into a hollow shape.
4. The dilator according to claim 1, wherein the spirally-arranged
protruding portion includes a coil comprising a wire wound around
on the outer peripheral surface of the shaft.
5. The dilator according to claim 1, wherein: the shaft includes a
first coil comprising a wire wound into a hollow shape, the
spirally-arranged protruding portion includes a second coil
comprising a wire wound around on the outer peripheral surface of
the shaft, and the wire of the first coil and the wire of the
second coil are wound in opposite directions.
6. The dilator according to claim 1, further comprising: a grip
portion provided at a proximal end of the shaft.
Description
[0001] This application is a continuation application of
International Application No. PCT/JP2018/035089, filed Sep. 21,
2018, which claims priority to International Application
PCT/JP2018/011673, filed Mar. 23, 2018. The contents of these
applications are incorporated herein by reference in their
entirety.
BACKGROUND
[0002] The disclosed embodiments relate to a dilator.
[0003] Dilators that enable treatment by enlarging a
penetration-hole formed in the wall of a patient's digestive tract
or the like are known. The distal end of the dilator is inserted
into the penetration-hole formed in the wall, and the
penetration-hole is expanded by pushing a tapered part into the
penetration-hole. Such a dilator is disclosed according to Japanese
Patent Document JP2008-11867.
SUMMARY
[0004] In the dilator mentioned above, a sufficient thrust could
not be achieved with respect to the tapered part, which experiences
an increased resistance when being pushed into a penetration-hole
or constricted part, and in some cases the penetration-hole or
constricted part could not be sufficiently expanded.
[0005] The present disclosure has an object of providing a dilator
that can easily widen the diameter of a penetration-hole formed in
the wall of a digestive tract or the like, and can suppress damage
to the wall of the digestive tract or the like.
[0006] In order to achieve the object, a dilator according to an
aspect of the present disclosure comprises a shaft in a hollow
shape, and a grip part that is provided on a proximal end of the
shaft. The shaft comprises a tapered part in which an outer
diameter of a distal end is smaller than an outer diameter of a
proximal end; and either (i) a distal end part that is provided on
a distal end side of the tapered part and which extends toward the
distal end side and a proximal end part that is provided on a
proximal end side of the tapered part and which extends toward the
proximal end side, or (ii) the proximal end part that is provided
on the proximal end side of the tapered part and which extends
toward the proximal end side, without the distal end part. A
spirally-arranged protruding portion is provided on an outer
peripheral face of the shaft, and the spirally-arranged protruding
portion has gaps between sections that are neighboring along an
axis of the shaft. If the shaft does not include the distal end
part, a pitch of sections of the spirally-arranged protruding
portion provided on the tapered part, which are neighboring along
the axis, is larger than the pitch of sections of the
spirally-arranged protruding portion provided on the proximal end
part, which are neighboring along the axis. If the shaft includes
the distal end part, a pitch of sections of the spirally-arranged
protruding portion provided on the tapered part, which are
neighboring along the axis, is larger than the pitch of sections of
the spirally-arranged protruding portion provided on the distal end
part or the proximal end part, which are neighboring, respectively,
along the axis.
BRIEF DESCRIPTION OF THE DRAWINGS
[0007] FIG. 1 is an overall view of a dilator of the disclosed
embodiments;
[0008] FIG. 2 is a diagram showing a distal end side section of a
dilator of the disclosed embodiments;
[0009] FIG. 3 is a diagram showing an overall view of a dilator of
the disclosed embodiments;
[0010] FIG. 4 is a partial cross-sectional view of a distal end
side section of a dilator of the disclosed embodiments;
[0011] FIG. 5 is an overall view of a dilator of the disclosed
embodiments;
[0012] FIG. 6 is a partial cross-sectional view of a distal end
side section of a dilator of the disclosed embodiments;
[0013] FIG. 7 is a partial cross-sectional view of a distal end
side section of a dilator of the disclosed embodiments;
[0014] FIG. 8 is a partial cross-sectional view of a distal end
side section of a dilator of the disclosed embodiments;
[0015] FIG. 9 is a partial cross-sectional view of a distal end
side section of a dilator of the disclosed embodiments;
[0016] FIG. 10 is a partial cross-sectional view of a distal end
side section of a dilator of the disclosed embodiments;
[0017] FIG. 11 is a partial cross-sectional view of a distal end
side section of a dilator of the disclosed embodiments;
[0018] FIG. 12 is a schematic view of a distal end side section of
the dilator of the disclosed embodiments;
[0019] FIG. 13 is a schematic view showing a distal end side
section of a dilator of the disclosed embodiments;
[0020] FIG. 14 is a schematic view showing a distal end side
section of a dilator of the disclosed embodiments;
[0021] FIG. 15 is a schematic view showing a distal end side
section of a dilator of the disclosed embodiments;
[0022] FIG. 16 is a schematic view showing a distal end side
section of a dilator of the disclosed embodiments; and
[0023] FIG. 17 is a diagram showing a distal end side section of a
dilator of the disclosed embodiments.
DETAILED DESCRIPTION
[0024] Hereinafter, embodiments of the present disclosure will be
described with reference to the drawings. Note that the dimensions
of the dilators shown in the drawings are dimensions shown for the
purpose of facilitating an understanding of the technical matters,
and do not correspond to the actual dimensions.
[0025] A dilator of the present disclosure will be described with
reference to the drawings. FIG. 1 is an overall view of a dilator 1
of the disclosed embodiments. Furthermore, in FIG. 1, the left side
of the drawing is the distal end side (far side) inserted into the
body, and the right side is the proximal end side (near side)
operated by an operator such as a physician.
[0026] In FIG. 1, the dilator 1 includes a multilayered body 7
including a first coil 3 formed by winding a plurality of metal
wires into a hollow shape, and a second coil 5 formed by winding a
single metal wire onto an outer peripheral face 3A of the first
coil 3 in an opposite direction (wound clockwise toward the distal
end) to the first coil 3 (wound counterclockwise toward the distal
end); and a hollow connector 9 connected to a proximal end of the
multilayered body 7.
[0027] The wires constituting the first coil 3 and the second coil
5 are, for example, metal wires made of stainless steel or a
superelastic alloy such as nickel-titanium, or are resin wires.
[0028] The first coil 3 is formed, for example, by winding ten
metallic wires made of stainless steel. The first coil 3 has a
hollow shape and is formed having a lumen 3B that passes through
from the distal end to the proximal end. The first coil 3 includes
a proximal end part 3C, a tapered part 3D, and a distal end part
3E. The first coil 3 corresponds to a shaft.
[0029] The proximal end part 3C is positioned on the proximal end
side of the dilator 1, and a connector 9 is connected to the
proximal end thereof. Furthermore, the proximal end part 3C has a
substantially constant outer diameter from the proximal end to the
distal end.
[0030] The tapered part 3D is positioned on the distal end side of
the proximal end part 3C, extends from the distal end of the
proximal end part 3C toward the distal end side, and has an outer
diameter that decreases toward the distal end side.
[0031] The distal end part 3E is located on the distal end side of
the tapered part 3D and extends from the distal end of the tapered
part 3D toward the distal end side. The distal end part 3E has a
substantially constant outer diameter from the proximal end to the
distal end. As a result, the first coil 3, which serves as the
shaft, has a hollow shape in which the outer diameter of the distal
end is smaller than the outer diameter of the proximal end.
[0032] The second coil 5 is, for example, a single metal wire which
is wound around onto the outer peripheral face 3A of the first coil
3 in an opposite direction (wound clockwise toward the distal end)
to the first coil 3 (wound counterclockwise toward the distal end).
Here, the metal wire is closely wound (without spacing) on the
proximal end side, and is wound with spacing on the distal end side
of the proximal end part 3C, the tapered part 3D, and the distal
end part 3E. A spirally-arranged protruding portion that protrudes
toward the exterior (radially outward from the outermost surface
and outermost part of the dilator 1) is provided on the outer
peripheral face 3A of the first coil 3 as a result of the section
of the second coil 5 being wound with spacing. That is, the section
of the second coil 5 wound with spacing forms a spirally-arranged
protruding portion on the outer peripheral face 3A of the first
coil 3. The spirally-arranged protruding portion has gaps between
sections that are neighboring (gaps between adjacent windings of
the metal wire) along the axis A (longitudinal axis) of the first
coil 3. The dilator 1 can also be moved forward by a rotation
operation of the dilator 1 as a result of a screw action of the
spirally-arranged protruding portion.
[0033] Furthermore, the pitch of sections provided on the tapered
part 3D, said sections being neighboring along the axis A of the
second coil 5, is configured to be larger than the pitch of
sections provided on the proximal end part 3C and the distal end
part 3E, said sections being neighboring along the axis A of the
second coil 5. That is to say, in terms of the sections being
neighboring along the axis A of the second coil 5, the pitch L1 on
the distal end side of the proximal end part 3C, the pitch L2 on
the tapered part 3D, and the pitch L3 on the distal end part 3E are
configured such that L1, L3<L2 (all the pitches L1 and all the
pitches L3 are smaller than any of the pitches L2). Note that the
pitches on the distal end side of the proximal end part 3C may be
equal or different. The pitches on the tapered part 3D may be equal
or different.
[0034] Furthermore, the metal wire of the second coil 5 is wound
such that the amount of separation between neighboring metal wires
gradually decreases toward the proximal end side of the proximal
end part 3C. As a result of this configuration, the rigidity of the
dilator 1 (multilayered body 7) in the axial direction can be
gradually changed, and the dilator 1 can easily advance along a
path even when a curved path is to be travelled.
[0035] The length of the dilator in the present embodiment and in
the other embodiments described below is, for example, 2000 mm, and
may be 1600 mm to 2500 mm; the length of the distal end part 3E is,
for example, 10 mm, and may be 0 to 100 mm; and further, the length
of the tapered part 3D is, for example, 30 mm, and may be 5 to 100
mm. The inner diameter at the distal end of the first coil 3 is,
for example, 0.7 mm, and may be 0.4 to 1.0 mm; and the inner
diameter at the proximal end of the first coil 3 is, for example,
1.5 mm, and may be 1.0 to 3.0 mm. The outer diameter at the distal
end of the second coil 5 is, for example, 1.84 mm, and may be 0.8
to 3.0 mm; and the outer diameter at the proximal end of the second
coil 5 is, for example, 2.64 mm, and may be 1.4 to 5.0 mm.
Furthermore, the diameter of the metal wires of the first coil 3
is, for example, 0.21 mm, and may be 0.1 to 0.5 mm; and the
diameter of the metal wires of the second coil 5 is, for example,
0.36 mm, and may be 0.1 to 0.5 mm.
[0036] The pitches L1 and L3 of the second coil 5 on the proximal
end part 3C and the distal end part 3E are, for example, 1.5 mm,
the pitch L2 of the second coil 5 on the tapered part 3D is, for
example, 2 mm, and the ratio between the two ((L1 or L3)/L2) is
0.75. The pitches L1 and L3 of the second coil 5 on the proximal
end part 3C and the distal end part 3E may be 0.2 to 4 mm, the
pitch L2 of the second coil 5 on the tapered part 3D may be 0.25 to
5 mm, and the ratio between the two is in a range of 0.04 to 1.
[0037] The connector 9, which is a grip part, is a part that an
operator uses to push the dilator into the body or perform a
rotation operation. The distal end of the connector 9 is connected
to the proximal end of the first coil 3 and the proximal end of the
second coil 5. The connector 9 is made of resin, and has a hollow
shape having a lumen which communicates with the lumen 3B of the
first coil 3.
[0038] In the dilator 1 of the present disclosure, a
spirally-arranged protruding portion (second coil 5) that protrudes
toward the exterior is provided on the outer peripheral face 3A of
first coil 3, which serves as the shaft, and the spirally-arranged
protruding portion has gaps between sections along the axial
direction of the first coil 3. This configuration not only enables
the dilator to be moved forward in a conventional fashion by a
pressing operation, but also to be moved forward by a rotation
operation as a result of the spirally-arranged protruding
portion.
[0039] Furthermore, the pitch of sections provided on the tapered
part 3D, said sections being neighboring along the axis A of the
second coil 5, is configured to be larger than the pitch of
sections provided on the proximal end part 3C and the distal end
part 3E, said sections being neighboring along the axis A of the
second coil 5. As a result, when the dilator 1 is rotated, the
tapered part 3D of the first coil 3 has a smaller frictional
resistance with the target object (for example, a digestive tract
such as the stomach, or the liver) than the proximal end part 3C
and the distal end part 3E. As a result, the diameter of a
penetration-hole formed in the wall of a digestive tract or the
like can be easily widened, and it is possible to suppress damage
to the target object which can occur due to intrusion into the
target object.
[0040] Moreover, because the shaft is constituted by the first coil
3, in which a plurality of metal wires is wound in a hollow shape,
the flexibility of the shaft, and the torquability by the first
coil 3 can be improved. Furthermore, because the spirally-arranged
protruding portion is composed of the second coil 5, in which a
single metal wire is wound around onto the outer peripheral face 3A
of the first coil 3, the spirally-arranged protruding portion can
be easily formed, and the elasticity of the second coil 5 enables
the flexibility of distal end of the dilator 1 to be ensured, and
the torquability to be improved. Moreover, because the wires of the
first coil 3 and the second coil 5 are wound in mutually opposite
directions, even when the dilator 1 is rotated in a direction that
opens the first coil 3, a force is applied in a direction that
closes the second coil 5, which inhibits the first coil 3 from
opening and enables the force applied to the connector 9 of the
dilator 1 to be delivered to the distal end side.
[0041] Next, an example of a usage mode of the dilator will be
described.
[0042] First, a target object is punctured with an introducer
needle to form a penetration-hole. Then, after inserting a guide
wire into a lumen of the introducer needle, the introducer needle
is removed.
[0043] Next, the proximal end of the guide wire is inserted into
the lumen of the dilator, and the dilator is inserted. Then, the
dilator is pushed forward while rotating the shaft to expand the
hole of the punctured part. At this time, the tapered portion
advances due to a screw action or the like of the spirally-arranged
protruding portion caused by a rotation operation of the shaft, and
the penetration-hole can be smoothly expanded by the tapered
part.
[0044] FIG. 2 is a diagram showing a distal end side section of a
dilator 10 of the disclosed embodiments.
[0045] Furthermore, in FIG. 2, the left side of the drawing is the
distal end side (far side) inserted into the body, and the right
side is the proximal end side (near side) operated by an operator
such as a physician.
[0046] The dilator 10 of the present embodiment has the same basic
structure as the dilator 1, and therefore, the same reference
numerals are given to the same members, and the description will
not be repeated.
[0047] In FIG. 2, the dilator 10 includes a multilayered body 17
including a first coil 3 formed by winding a plurality of metal
wires into a hollow shape, and a second coil 5 formed by winding a
single metal wire onto an outer peripheral face 3A of the first
coil 3 in an opposite direction (wound clockwise toward the distal
end) to the first coil 3 (wound counterclockwise toward the distal
end); and a hollow connector 9 connected to a proximal end of the
multilayered body 17. However, the dilator 10 differs from the
dilator 1 in that a tip 6 is provided instead of the distal end
part 3E of the first coil 3 of the dilator 1. In the present
embodiment, the first coil 3, which is provided with the tip 6 on
the distal end, corresponds to the shaft.
[0048] The tip 6 is formed by pouring a brazing material (such as a
silver-tin brazing material or a gold-tin brazing material) into
the distal end of the first coil 3, and the shape thereof is a
substantially cylindrical hollow shape. Moreover, unlike the distal
end of the multilayered body 7, the surface of the tip 6 does not
have an uneven shape, and is flat.
[0049] In the present embodiment, the pitch of sections provided on
the tapered part 3D, said sections being neighboring along the axis
A of the second coil 5, is configured to be larger than the pitch
of sections provided on the proximal end part 3C, said sections
being neighboring along the axis A of the second coil 5. That is to
say, in terms of the sections being neighboring along the axis A of
the second coil 5, the pitch L11 on the distal end side of the
proximal end part 3C and the pitch L12 on the tapered part 3D are
configured such that L11<L12.
[0050] According to the dilator 10 having such a configuration, the
same effects as those of the dilator 1 can be obtained. That is to
say, when the dilator 10 is rotated, the tapered part 3D of the
first coil 3 has a smaller frictional resistance with the target
object (for example, a digestive tract such as the stomach, or the
liver) than the proximal end part 3C. As a result, the diameter of
a penetration-hole formed in the wall of a digestive tract or the
like can be easily widened, and it is possible to suppress damage
to the target object which can occur due to intrusion into the
target object. Furthermore, because the tip 6 having a flat surface
is connected to the distal end of the multilayered body 17, the
insertability into a punctured part is further improved by first
pushing the dilator with respect to the punctured part, and then
pushing the dilator while applying a rotation.
[0051] FIG. 3 is an overall view of a dilator 20 of the disclosed
embodiments. Furthermore, in FIG. 3, the left side of the drawing
is the distal end side (far side) inserted into the body, and the
right side is the proximal end side (near side) operated by an
operator such as a physician.
[0052] In FIG. 3, the dilator 20 includes a shaft 21, a
spirally-arranged protruding portion 22, and a connector 9 that is
connected to the proximal end of the shaft 21.
[0053] The shaft 21 has a hollow shape and is formed having a lumen
21A that passes through from the distal end to the proximal end.
Furthermore, the shaft 21 includes a proximal end part 23, a
tapered part 24, and a distal end part 25.
[0054] The material forming the shaft 21 and the spirally-arranged
protruding portion 22 is not particularly limited as long as it
ensures the flexibility of the tapered part 24 and the distal end
part 25 and is biocompatible, and examples include stainless steel,
superelastic alloy materials such as nickel-titanium alloy, and
synthetic resins such as polyvinyl chloride resins, urethane
resins, polyolefin resins, polyamide resins, and fluorine
resins.
[0055] The proximal end part 23 is positioned on the proximal end
side of the dilator 20, and a connector 9 is connected to the
proximal end thereof. Furthermore, the proximal end part 23 is
provided on the proximal end side of the tapered part 24 and
extends toward the proximal end side. The proximal end part 23 has
a substantially constant outer diameter from the proximal end to
the distal end.
[0056] The tapered part 24 is connected to the distal end of the
proximal end part 23, extends from the distal end of the proximal
end part 23 toward the distal end side, and has a shape which is
tapered toward the distal end side.
[0057] The distal end part 25 is connected to the distal end of the
tapered part 24 and extends from the distal end of the tapered part
24 toward the distal end side. The distal end part 25 has a
substantially constant outer diameter from the proximal end to the
distal end. As a result, the shaft 21 has a hollow shape in which
the outer diameter of the distal end is smaller than the outer
diameter of the proximal end.
[0058] A spirally-arranged protruding portion 22 is provided on the
outer peripheral face 21B of the shaft 21 so as to protrude toward
the exterior (from the outermost surface and outermost part of the
dilator 20). The spirally-arranged protruding portion 22 is
provided on a distal end side section of the proximal end part 23,
the tapered part 24, and the distal end part 25, and has gaps
between sections that are neighboring along an axis A of the shaft
21. That is to say, sections of the spirally-arranged protruding
portion 22 that are neighboring are mutually separated. The
spirally-arranged protruding portion 22 is integrally formed with
the shaft 21 by casting or the like.
[0059] The pitch of sections provided on the tapered part 24, said
sections being neighboring along the axis A of the
spirally-arranged protruding portion 22, is configured to be larger
than the pitch of sections provided on the proximal end part 23 and
the distal end part 25, said sections being neighboring along the
axis A of the spirally-arranged protruding portion 22. That is to
say, in terms of the sections being neighboring along the axis A of
the spirally-arranged protruding portion 22, the pitch L21 on the
proximal end part 23, the pitch L22 on the tapered part 24, and the
pitch L23 on the distal end part 25 are configured such that L21,
L23<L22 (all the pitches L21 and all the pitches L23 are smaller
than any of the pitches L22). Note that the pitches on the proximal
end part 23 and the distal end part 25 may be equal or different.
The pitches on the tapered part 24 may be equal or different.
[0060] In the dilator 20 of the present embodiment, a
spirally-arranged protruding portion 22 that protrudes toward the
exterior is provided on the outer peripheral face 21B of shaft 21,
and the spirally-arranged protruding portion 22 has gaps between
sections that are neighboring along the axis A of the shaft 21.
This configuration not only enables the dilator to be moved forward
in a conventional fashion by a pressing operation, but also to be
moved forward by a rotation operation as a result of the
spirally-arranged protruding portion 22.
[0061] Furthermore, the pitch of sections provided on the tapered
part 24, said sections being neighboring along the axis A of the
spirally-arranged protruding portion 22, is configured to be larger
than the pitch of sections provided on the proximal end part 23 and
the distal end part 25, said sections being neighboring along the
axis A of the spirally-arranged protruding portion 22. As a result,
when the dilator 20 is rotated, the tapered part 24 of the shaft 21
has a smaller frictional resistance with the target object (for
example, a digestive tract such as the stomach, or the liver) than
the proximal end part 23 and the distal end part 25. As a result,
the diameter of a penetration-hole formed in the wall of a
digestive tract or the like can be easily widened, and it is
possible to suppress damage to the target object which can occur
due to intrusion into the target object.
[0062] FIG. 4 is a partial cross-sectional view of a distal end
side section of a dilator 30 of the disclosed embodiments.
Furthermore, in FIG. 4, the left side of the drawing is the distal
end side (far side) inserted into the body, and the right side is
the proximal end side (near side) operated by an operator such as a
physician.
[0063] In FIG. 4, the dilator 30 includes a shaft 31, a
spirally-arranged protruding portion 32, and a connector 9 that is
connected to the proximal end of the shaft 31 (see FIG. 3). The
materials forming the shaft 31 and the spirally-arranged protruding
portion 32 are the same as the materials forming the shaft 21 and
the spirally-arranged protruding portion 22 of the dilator 20.
[0064] The shaft 31 has a hollow shape and is formed having a lumen
31A that passes through from the distal end to the proximal end.
Furthermore, the shaft 31 includes a proximal end part 33 and a
tapered part 34. The dilator 30 of the present embodiment differs
from the dilator 20 in that it does not have a distal end part.
[0065] The configurations of the proximal end part 33 and the
tapered part 34 are the same as those of the proximal end part 23
and the tapered part 24. Furthermore, a spirally-arranged
protruding portion 32 is provided on the outer peripheral face 31B
of the shaft 31 so as to protrude toward the exterior (from the
outermost surface and outermost part of the dilator 30). The
spirally-arranged protruding portion 32 is provided on a distal end
side section of the proximal end part 33, and the tapered part 34,
and has gaps between sections that are neighboring along an axial
direction of the shaft 31. That is to say, sections of the
spirally-arranged protruding portion 32 that are neighboring are
mutually separated. The spirally-arranged protruding portion 32 is
integrally formed with the shaft 31 by casting or the like.
[0066] The pitch of sections provided on the tapered part 34, said
sections being neighboring along the axis A of the
spirally-arranged protruding portion 32, is configured to be larger
than the pitch of sections provided on the proximal end part 33,
said sections being neighboring along the axis A of the
spirally-arranged protruding portion 32. That is to say, in terms
of the sections being neighboring along the axis A of the
spirally-arranged protruding portion 32, the pitch L31 on the
proximal end part 33 and the pitch L32 on the tapered part 34 are
configured such that L31<L32 (all the pitches L31 are smaller
than any of the pitches L32). Note that the pitches on the proximal
end part 33 may be equal or different. The pitches on the tapered
part 34 may be equal or different.
[0067] In the dilator 30 of the present disclosure, a
spirally-arranged protruding portion 32 that protrudes toward the
exterior is provided on the outer peripheral face 31B of shaft 31,
and the spirally-arranged protruding portion 32 has gaps between
sections that are neighboring along the axis A of the shaft 31.
This configuration not only enables the dilator to be moved forward
in a conventional fashion by a pressing operation, but also to be
moved forward by a rotation operation as a result of the
spirally-arranged protruding portion 32.
[0068] Furthermore, the pitch of sections provided on the tapered
part 34, said sections being neighboring along the axis A of the
spirally-arranged protruding portion 32, is configured to be larger
than the pitch of sections provided on the proximal end part 33,
said sections being neighboring along the axis A of the
spirally-arranged protruding portion 32. As a result, when the
dilator 30 is rotated, the tapered part 34 of the shaft 31 has a
smaller frictional resistance with the target object (for example,
a digestive tract such as the stomach, or the liver) than the
proximal end part 33. As a result, the diameter of a
penetration-hole formed in the wall of a digestive tract or the
like can be easily widened, and it is possible to suppress damage
to the target object which can occur due to intrusion into the
target object.
[0069] Although the embodiments of the present disclosure have been
described above, the present disclosure is not limited to these
embodiments, and various modifications can be made.
[0070] For example, as shown in FIG. 5, the dilator 1 may be a
dilator 100 in which the second coil 5 has gaps between sections
that are neighboring along the axial direction of the first coil 3
up to the proximal end thereof.
[0071] Furthermore, in terms of the spirally-arranged protruding
portion 22 of the dilator 20 shown in FIG. 3, the pitch of sections
provided on the tapered part 24, said sections being neighboring
along the axis A of the spirally-arranged protruding portion 22, is
configured to be larger than the pitch of sections provided on the
proximal end part 23 and the distal end part 25, said sections
being neighboring along the axis A of the spirally-arranged
protruding portion 22. However, like the dilator 40 shown in FIG.
6, the pitches (L21 and L22) of sections provided on the tapered
part 24 and the proximal end part 23, said sections being
neighboring along the axis A of the spirally-arranged protruding
portion 22, may be configured to be larger than the pitch (L23) of
sections provided on the distal end part 25, said sections being
neighboring along the axis A of the spirally-arranged protruding
portion 22. That is to say, a configuration is possible where
L23<L21, L22 (all the pitches L23 are smaller than any of the
pitches L21 and any of the pitches L22). Note that the pitches on
the distal end part 25 may be equal or different. The pitches on
the tapered part 24 and the proximal end part 23 may be equal or
different. As a result, when the dilator 40 is rotated, the tapered
part 24 of the shaft 21 has a smaller frictional resistance with
the target object (for example, a digestive tract such as the
stomach, or the liver) than the distal end part 25. As a result,
the diameter of a penetration-hole formed in the wall of a
digestive tract or the like can be easily widened, and it is
possible to suppress damage to the target object which can occur
due to intrusion into the target object.
[0072] Furthermore, like the dilator 50 shown in FIG. 7, the
pitches (L22 and L23) of sections provided on the tapered part 24
and the distal end part 25, said sections being neighboring along
the axis A of the spirally-arranged protruding portion 22, may be
configured to be larger than the pitch (L21) of sections provided
on the proximal end part 23, said sections being neighboring along
the axis A of the spirally-arranged protruding portion 22. That is
to say, a configuration is possible where L21<L23, L22 (all the
pitches L21 are smaller than any of the pitches L22 and and any of
the pitches L23). Note that the pitches on the proximal end part 23
may be equal or different. The pitches on the tapered part 24 and
the distal end part 25 may be equal or different. As a result, when
the dilator 50 is rotated, the tapered part 24 of the shaft 21 has
a smaller frictional resistance with the target object (for
example, a digestive tract such as the stomach, or the liver) than
the proximal end part 23. As a result, the diameter of a
penetration-hole formed in the wall of a digestive tract or the
like can be easily widened, and it is possible to suppress damage
to the target object which can occur due to intrusion into the
target object.
[0073] Furthermore, in the embodiments described above, a dilator 1
was described in which the shaft and the spirally-arranged
protruding portion are both constituted by a coil, and dilators 20,
30, 40, and 50 were described in which the shafts 21 and 31, and
the spirally-arranged protruding portions 22 and 32 are integrally
formed by casting or the like. However, the dilator may be formed
such that only the shaft is formed by casting, and the
spirally-arranged protruding portion is constituted by a coil. That
is to say, the dilator also may be a dilator 200 configured by a
shaft 21 and a spirally-arranged protruding portion (second coil 5)
as shown in FIG. 8, a dilator 300 configured by a shaft 31 and a
spirally-arranged protruding portion (second coil 5) as shown in
FIG. 9, a dilator 400 configured by a shaft 21 and a
spirally-arranged protruding portion (second coil 5) as shown in
FIG. 10, or a dilator 500 configured by a shaft 21 and a
spirally-arranged protruding portion (second coil 5) as shown in
FIG. 11.
[0074] Note that the pitches of sections, being neighboring along
the axis A of the spirally-arranged protruding portion, (second
coil 5) are configured in the dilator 200 of FIG. 8 such that L21,
L23<L22, are configured in the dilator 300 of FIG. 9 such that
L31<L32, are configured in the dilator 400 of FIG. 10 such that
L23<L21, L22, and are configured in the dilator 500 of FIG. 11
such that L21<L22, L23.
[0075] Furthermore, as shown in FIG. 12, in the dilator 1 (FIG. 1),
the dilator 20 (FIG. 3), and the dilator 200 (FIG. 8), the pitch of
sections provided on the tapered parts 3D and 24, said sections
being neighboring along the axis A of the second coil 5 and the
spirally-arranged protruding portion 22, is configured to be larger
than the pitch of sections provided on the proximal end parts 3C
and 23 and the distal end parts 3E and 25, said sections being
neighboring along the axis A of the second coil 5 and the
spirally-arranged protruding portion 22. That is to say, as shown
in FIG. 12, in terms of the sections neighboring along the axis A
of the second coil 5 and the spirally-arranged protruding portion
22, the pitch La on the distal end parts 3E and 25, the pitch Lb on
the tapered parts 3D and 24, and the pitch Lc on the distal end
side of the proximal end parts 3C and 23 are configured such that
La, Lc<Lb.
[0076] However, if the relationship La<Lb is satisfied, for
example, dilators 1A, 20A, and 200A, where La<Lb=Lc (see FIG.
13), and the dilators 1B, 20B, and 200B, where La<Lb<Lc (see
FIG. 14) are also possible. Furthermore, if the relationship
Lc<Lb is satisfied, for example, dilators 1C, 20C, and 200C,
where Lc<Lb=La (see FIG. 15), and dilators 1D, 20D, and 200D,
where Lc<Lb<La (see FIG. 16) are also possible.
[0077] Note that the dilators 1A, 1B, 1C, and 1D are the
embodiments of dilators where the shaft and the spirally-arranged
protruding portion are both configured by a coil like the dilator
of FIG. 1, the dilators 20A, 20B, 20C, and 20D are the embodiments
of dilators where the shaft and the spirally-arranged protruding
portion are both integrally formed by casting or the like as in the
dilator of FIG. 3, and further, the dilators 200A, 200B, 200C, and
200D are the embodiments of dilators where the shaft is formed by
casting or the like, and the spirally-arranged protruding portion
is configured by a coil like the dilator of FIG. 8.
[0078] Furthermore, in a dilator where the shaft and the
spirally-arranged protruding portion are both integrally formed by
casting or the like in a similar fashion to the dilator of FIG. 3,
the spirally-arranged protruding portion may be provided up to the
proximal end of the shaft. Moreover, in all of the dilators shown
in the other diagrams, the second coil provided on the outer
circumference of the shaft may or may not have gaps between
sections that are neighboring along the axis of the shaft up to the
proximal end thereof.
[0079] Moreover, in the embodiments above, although the first coil
3 was described as a hollow coil body formed from ten wires, the
number of wires is not limited to ten, and may be one or more. In
addition, in the embodiments above, although the second coil 5 was
described as a hollow coil body formed from a single wire, the
number of wires is not limited to one, and may be one or more.
[0080] Furthermore, although the tip 6 of the dilator 10 is formed
by pouring a brazing material into the distal end of the
multilayered body 17, a tip 6 having a flat surface may be formed
by polishing the outer circumference of the second coil 5 and/or
the first coil 3 near the distal end part of the multilayered body
17.
[0081] Moreover, although the tip 6 of the dilator 10 shown in FIG.
2 is fixed to the distal end of the multilayered body 17, the tip 6
may be fixed to the distal end of any of the dilators shown in the
other drawings, such as the distal end of the shaft 21 of the
dilator 20, or the distal end of the shaft 31 of the dilator
30.
[0082] Furthermore, the multilayered bodies 7 and 17 of the
dilators 1, 10, and 100, and the outer circumference of the
spirally-arranged protruding portions 22 and 32 of the dilators 20,
30, 40, 50, 200, 300, 400, and 500 may be coated with a resin. For
example, as shown in FIG. 17, the outer circumference of the shaft
21 and the spirally-arranged protruding portion 22 of the dilator
20 may be coated with a resin 26. The resin 26 can improve the
slidability. Also, as a result of this coating, in the embodiments
where the shaft is constituted by the first coil, it is possible to
inhibit living tissue from becoming trapped between the wires of
the first coil (sections that are neighboring along the shaft axis
of the first coil constituting the shaft), or in the embodiments
where the spirally-arranged protruding portion includes the second
coil, it is possible to inhibit living tissue from becoming trapped
between the second coil and the shaft. When the outer circumference
of the shaft 21 is coated by the resin 26, the sections of the
proximal end part 23, the tapered part 24, and the distal end part
25 that are coated by the resin 26 correspond to the shaft 21, and
the sections that protrude toward the exterior from the outer
peripheral face 21B of the shaft 21 correspond to the
spirally-arranged protruding portion 22. Examples of the resin 26
include biocompatible resin materials such as polyamide resins and
fluororesins, and hydrophilic coating materials, and the thickness
thereof is, for example, 0.1 to 300 .mu.m. In addition, although
the shafts 21 and 31 were integrally formed with the
spirally-arranged protruding portions 22 and 32, these may be
separately formed.
[0083] In the embodiments shown in FIG. 1 to FIG. 17, dilators not
having a coating on the surface of the shaft (other than the resin
36 in FIG. 17) were described. However, the shaft may have various
coatings on the surface side (including parts between the shaft and
the spirally-arranged protruding portion). Examples of the coating
include a protective film (a typical example being a plating film)
on the surface of the shaft, and a base film for improving the
adhesion between the shaft and the spirally-arranged protruding
portion.
[0084] In the embodiments shown in FIG. 1 to FIG. 17, the
spirally-arranged protruding portion preferably does not constitute
a blade. The dilators of the present embodiments expand a
pre-formed penetration-hole in a target object (an example being
the wall of a digestive tract such as a patient's stomach).
Therefore, if the spirally-arranged protruding portion constitutes
a blade, the living tissue on the inner surface of the
penetration-hole becomes damaged.
[0085] Therefore, the cross-sectional shape of the
spirally-arranged protruding portion (for example, the shape of a
cross-section taken orthogonally to the helix direction of the
spirally-arranged protruding portion shown in FIG. 3) preferably
does not include a corner portion having an acute angle on the
radially outer end part of the shaft. That is to say, the end part
preferably has a part which is formed having, for example, a shape
which contains a corner portion having an obtuse angle, or a curve
(for example, a curve containing part of a circle or an
ellipse).
* * * * *