WO2023073942A1

WO2023073942A1 - Dilator kit

Info

Publication number: WO2023073942A1
Application number: PCT/JP2021/040072
Authority: WO
Inventors: 貴行堀
Original assignee: 朝日インテック株式会社
Priority date: 2021-10-29
Filing date: 2021-10-29
Publication date: 2023-05-04

Abstract

This dilator kit comprises: a catheter having a lumen; and a dilator, the dilator being accommodated in the lumen of the catheter in an assembled state. The catheter has a tip-side engagement section and a base-side engagement section that respectively engage with the dilator in the assembled state. The dilator has a tip-side engaged section that engages with the tip-side engagement section of the catheter and a base-side engaged section that engages with the base-side engagement section of the catheter in the assembled state. In a separated state in which the catheter and the dilator are separated from each other, the length between the tip-side engaged section and the base-side engaged section of the dilator is greater than the length between the tip-side engagement section and the base-side engagement section of the catheter.

Description

dilator kit

The present invention relates to a dilator kit.

A dilator is known as a device that assists the insertion of a catheter into living tissue. The dilator is elongated and has a pointed tip. When inserting a catheter into a living tissue, the dilator is inserted into the catheter, the dilator is accommodated in the lumen of the catheter, and the tip of the dilator is exposed from the tip side opening of the catheter (hereinafter also referred to as the "assembled state"). call). The distal end portion of the guide wire is previously inserted into the biological tissue using a puncture needle or the like, and the assembled dilator kit is inserted into the biological tissue from the distal end of the dilator along the guide wire. Since the tip of the dilator can dilate the subcutaneous tissue, the insertion resistance of the catheter into the living tissue can be reduced. For example, Patent Literature 1 discloses a catheter assembly that includes a catheter and a dilator.

JP 2019-154903 A

Here, when dilating the subcutaneous tissue with the tip of the dilator, it is necessary to push it in somewhat strongly because it receives resistance from the skin and subcutaneous tissue. In this regard, in the technique described in Patent Document 1, the distal end of the catheter is configured only along the outer peripheral surface of the dilator-side base portion having a substantially constant outer diameter, so the catheter receives a pushing force from the hand. There is a problem that the dilator stretches in the pushing direction or receives resistance from the skin and withdraws (moves) toward the proximal side within the catheter, making it difficult to insert the catheter into the living tissue. .

The present invention has been made to solve at least part of the above-described problems, and aims to provide a dilator kit that allows easy insertion of a catheter into living tissue.

The present invention has been made to solve at least part of the above problems, and can be implemented as the following forms.

(1) According to one aspect of the present invention, there is provided a dilator kit comprising a catheter having a lumen and a dilator, wherein the dilator is accommodated in the lumen of the catheter in an assembled state. In this dilator kit, the catheter has a distal side engaging portion and a proximal side engaging portion that respectively engage with the dilator in the assembled state, and the dilator has the dilator in the assembled state. A distal side engaged portion that engages with a distal side engaging portion, and a proximal side engaged portion that engages with the proximal side engaging portion of the catheter, wherein the catheter and the dilator is separated, the length between the distal side engaged portion and the proximal side engaged portion of the dilator is equal to the distal side engaged portion and the proximal side engaged portion of the catheter longer than the length between the parts.

According to this configuration, in the separated state in which the catheter and the dilator are separated, the length between the distal end side engaged portion and the proximal side engaged portion of the dilator is the same as the distal end side engaging portion and the proximal end of the catheter. It is longer than the length between the end side engaging portions. Therefore, in an assembled state in which the dilator is accommodated in the lumen of the catheter, the distal end side engaging portion and the distal end side engaged portion are engaged with each other while the catheter is elongated in the longitudinal direction. The end side engaging portion and the base end side engaged portion are engaged. In this way, in the dilator kit of this configuration, the catheter is already stretched in the assembled state. direction) can be suppressed. Further, in the assembled state, the distal engaging portion and the distal engaged portion are engaged, and the proximal engaging portion and the proximal engaged portion are engaged. It is possible to suppress the occurrence of an event in which the dilator that receives resistance from the catheter retracts toward the proximal side within the catheter. As a result, with the dilator kit having this configuration, the catheter can be easily inserted into the living tissue.

(2) In the dilator kit of the above aspect, the first length is the length between the distal side engaging portion and the proximal side engaging portion of the catheter in the assembled state, and the length of the catheter in the separated state is When the length between the distal side engaging portion and the proximal side engaging portion is defined as a second length, the difference between the first length and the second length is within a range of 1 mm or more and 30 mm or less. may be in
According to this configuration, the first length between the distal end side engaging portion and the proximal side engaging portion of the catheter in the assembled state, and the distal end side engaging portion and the proximal side engaging portion of the catheter in the separated state. The difference from the second length between (first length - second length) is in the range of 1 mm or more and 30 mm or less. Therefore, it is possible to suppress the expansion of the catheter in the pushing direction when receiving the pushing force from the hand, and it is possible to suppress the excessive expansion of the catheter when changing from the separated state to the assembled state.

(3) In the dilator kit of the above aspect, the difference between the first length and the second length may be in the range of 5 mm or more and 15 mm or less.
According to this configuration, the difference between the first length and the second length (the first length - the second length) is within the range of 5 mm or more and 15 mm or less, so that when a pushing force is applied from the hand, The extension of the catheter in the direction in which it is pushed in can be further suppressed, and excessive extension of the catheter when changing from the separated state to the assembled state can be further suppressed.

(4) In the dilator kit of the above aspect, the elastic modulus of the catheter may be smaller than the elastic modulus of the dilator.
According to this configuration, since the elastic modulus of the catheter is smaller than that of the dilator, the deliverability of the catheter can be improved, and the skin can be easily expanded by the dilator.

(5) In the dilator kit of the above aspect, the catheter has a hollow shaft portion, the dilator has an elongated main body portion, and the main body portion of the dilator has a dilator extending from the distal end side to the proximal end side. A tapered portion with an outer diameter gradually increasing toward the shaft is provided. An inner peripheral surface of a tip portion of the hollow shaft portion may function as the tip side engaging portion, and an outer peripheral surface of the tapered portion may function as the tip side engaged portion.
According to this configuration, the inner peripheral surface of the distal end portion of the hollow shaft portion of the catheter is engaged with the outer peripheral surface of the tapered portion of the dilator, so that the inner peripheral surface of the distal end portion of the hollow shaft portion is engaged with the distal end side. The outer peripheral surface of the tapered portion functions as a tip side engaged portion. For this reason, a lumen (device lumen) that is generally provided in a catheter and a taper structure on the tip side that is generally provided in a dilator are used to form a tip-side engaging portion and a tip-side engaged portion. It is possible to realize an engagement structure with the part.

(6) In the dilator kit of the above aspect, the catheter further has a first connector provided at the proximal end portion of the hollow shaft portion, and the dilator is further provided at the proximal end portion of the body portion. In the assembled state, the outer peripheral surface of the first connector engages with the inner peripheral surface of the second connector, so that the outer peripheral surface of the first connector The inner peripheral surface of the second connector may function as the end side engaging portion, and the base end side engaged portion.
According to this configuration, the outer peripheral surface of the first connector of the catheter and the inner peripheral surface of the second connector of the dilator are engaged with each other, so that the outer peripheral surface of the first connector functions as a proximal side engaging portion, The inner peripheral surface of the second connector functions as a proximal side engaged portion. Therefore, the engagement structure between the proximal side engaging portion and the proximal side engaged portion can be realized using a connector that is generally provided in many catheters and dilators.

(7) In the dilator kit of the above aspect, the hollow shaft portion of the catheter includes a tip taper portion whose outer diameter and inner diameter are gradually enlarged from the tip side to the base end side, and the tip taper portion. and a large-diameter portion having a substantially constant outer diameter disposed on the proximal end side of the hollow shaft portion, and in the longitudinal section of the hollow shaft portion, the outer peripheral surface of the tip taper portion and the outer periphery of the large-diameter portion The first acute angle is defined as a first acute angle, and the second acute angle is defined as an acute angle formed between the inner peripheral surface of the tip tapered portion and the outer peripheral surface of the large-diameter portion. can also be large.
According to this configuration, in the longitudinal section of the hollow shaft portion of the catheter, the first acute angle formed by the outer peripheral surface of the tip tapered portion and the outer peripheral surface of the large diameter portion is the inner peripheral surface of the tip tapered portion and the outer peripheral surface of the large diameter portion. Since it is larger than the second acute angle formed by the two surfaces, the thickness of the tapered portion at the distal end of the catheter can be gradually reduced from the proximal end side to the distal end side. As a result, the distal end side of the distal tapered portion can be configured more flexibly than the proximal end side, and the step between the distal end of the catheter and the dilator in the assembled state can be reduced.

The present invention can be implemented in various aspects, for example, a dilator, a catheter, a dilator kit having a dilator and a catheter, a dilator kit having a medical device other than a dilator and a catheter, manufacturing methods thereof, and the like. can be realized in the form of

FIG. 4 is an explanatory diagram illustrating the configuration of a dilator kit; FIG. 4 is an explanatory diagram illustrating the configuration of the dilator kit in an assembled state; FIG. 3 is an explanatory view illustrating the cross-sectional configuration of the distal end side of the dilator kit of FIG. 2; FIG. 4 is a diagram showing how the dilator kit of the present embodiment is inserted into a living tissue; FIG. 10 is a diagram showing how a dilator kit of a comparative example is inserted into a living tissue; FIG. 10 is a diagram showing how a dilator kit of a comparative example is inserted into a living tissue; FIG. 10 is an explanatory diagram illustrating the configuration of the dilator kit of the second embodiment; FIG. 11 is an explanatory diagram illustrating the configuration of a dilator kit according to a third embodiment; FIG. 11 is an explanatory diagram illustrating the configuration of a dilator kit according to a fourth embodiment; FIG. 11 is an explanatory diagram illustrating the configuration of a dilator kit according to a fifth embodiment; FIG. 11 is an explanatory diagram illustrating the configuration of a dilator kit according to a sixth embodiment; FIG. 11 is an explanatory diagram illustrating the configuration of a dilator kit of a seventh embodiment;

<First embodiment>
FIG. 1 is an explanatory diagram illustrating the configuration of a dilator kit. The

dilator kits

1 and 2 comprise a catheter 1 and a dilator 2. FIG. 1 shows the

dilator kits

1 and 2 in a state in which the catheter 1 and the dilator 2 are separated (hereinafter also referred to as "separated state"). In addition, in FIG. 1, the lumens formed inside the catheter 1 and the dilator 2 are illustrated by dashed lines. The

dilator kits

1 and 2 of the present embodiment have a configuration described later, so that the catheter 1 can be easily inserted into living tissue.

In FIG. 1, the axis O (one-dot chain line) that passes through the centers of the catheter 1 and the dilator 2 is shown. Hereinafter, the centers of the catheter 1 and the dilator 2 in the inserted state will be described as being aligned with the axis O, but the centers in the inserted state may be different. In addition, FIG. 1 illustrates XYZ axes that are orthogonal to each other. The X-axis corresponds to the longitudinal direction of the catheter 1 and the dilator 2, the Y-axis corresponds to the height direction of the catheter 1 and the dilator 2, and the Z-axis corresponds to the width direction of the catheter 1 and the dilator 2. The left side (−X axis direction) of FIG. 1 is called the “distal side” of the catheter 1, the dilator 2, and each component, and the right side (+X axis direction) of FIG. 1 is the catheter 1, the dilator 2, and each component. Called "proximal". In addition, among both ends in the longitudinal direction (X-axis direction) of the catheter 1, the dilator 2, and each component, one end located on the distal side is called the "distal end", and the other end located on the proximal side is called the "proximal end". ”. Also, the distal end and the vicinity thereof are referred to as the "distal portion", and the proximal end and the vicinity thereof are referred to as the "basal end portion". The distal side is inserted into the living body, and the proximal side is operated by an operator such as a doctor. These points are also common in FIG. 1 and subsequent figures.

The catheter 1 of the present embodiment is a guiding catheter for passing through and delivering medical devices such as guide wires and balloon catheters. The catheter 1 has a hollow shaft portion 100 and a first connector 190 provided at the proximal end portion of the hollow shaft portion 100 .

The hollow shaft portion 100 is a long tube-shaped member having a tip tapered portion 101 on the tip side and a large diameter portion 102 on the base end side. The distal tapered portion 101 is a portion where both the outer diameter and the inner diameter of the hollow shaft portion 100 are gradually enlarged from the distal side toward the proximal side. The large-diameter portion 102 is located closer to the proximal side than the distal tapered portion 101, and is a portion in which both the outer diameter and the inner diameter of the hollow shaft portion 100 have substantially constant sizes. In this embodiment, "substantially constant" is synonymous with "substantially constant", and means to be substantially constant while allowing fluctuations caused by manufacturing errors or the like. The outer diameter, inner diameter, and length of the hollow shaft portion 100, the tip tapered portion 101, and the large diameter portion 102 can be determined arbitrarily.

The first connector 190 is, for example, a member used by the operator to hold the catheter 1. The first connector 190 has a housing portion 191, a wing portion 192, and a connection portion 193 from the distal end side to the proximal end side. The accommodating portion 191 is a cylindrical member having an outer diameter that gradually increases from the distal end side to the proximal end side. Inside the accommodating portion 191, the proximal end portion of the large-diameter portion 102 of the hollow shaft portion 100 is accommodated and fixed. The blade portion 192 is a tubular member having a pair of blades for the operator to grasp. The connecting portion 193 is a cylindrical member having a disk-shaped protruding portion protruding in the circumferential direction (YZ-axis direction) at its base end portion. A male thread for screwing with the connecting portion 291 of the second connector 290 of the dilator 2 is formed on the outer peripheral surface of the projecting portion of the connecting portion 193 . Note that the accommodating portion 191, the blade portion 192, and the connecting portion 193 may be integrally molded.

In the catheter 1, the lumen of the hollow shaft portion 100 and the lumen of each member of the first connector 190 communicate with each other to form a device lumen 1L. The device lumen 1L is a lumen for inserting a medical device such as a guide wire or a balloon catheter into the catheter 1 . The device lumen 1L is also a lumen for inserting the dilator 2 through the catheter 1. As shown in FIG. An opening at the distal end of the catheter 1 that communicates the device lumen 1L with the outside is also called a "tip opening 1a". At the proximal end of the catheter 1, an opening communicating between the device lumen 1L and the outside is also referred to as a "base end opening 1b".

In the catheter 1, the hollow shaft portion 100 and the first connector 190 can be made of, for example, polyamide, polyester, polyurethane, fluororesins such as polytetrafluoroethylene (PTFE), or other known resin materials. The hollow shaft portion 100 of the catheter 1 may have a single-layer structure or a multi-layer structure consisting of two or more layers. In the case of a multi-layer structure, the constituent materials in each layer may be the same or different. Further, a metal reinforcing member may be embedded in the hollow shaft portion 100 or between the layers. For the reinforcing member, a coil shape obtained by spirally winding a wire or a mesh shape obtained by weaving the wire can be used. The first connector 190 may be made of known resin materials such as polyamide, polypropylene, polycarbonate, polyacetal, and polyethersulfone.

The dilator 2 of this embodiment is an instrument that assists the insertion of a catheter into living tissue by dilating the skin, subcutaneous tissue, and blood vessel wall. The dilator 2 has a body portion 200 and a second connector 290 provided at the proximal end portion of the body portion 200 .

The main body part 200 is a long tubular member having a tapered part 201 on the distal end side and a large diameter part 202 on the proximal end side. The tapered portion 201 is a portion having an outer diameter that gradually increases from the distal side toward the proximal side. The large-diameter portion 202 is arranged closer to the base end side than the tapered portion 201 and is a portion having a substantially constant outer diameter of the body portion 200 . The outer diameter Φ202 of the large diameter portion 202 is smaller than the inner diameter Φ102 of the large diameter portion 102 of the catheter 1 . In addition, in the body portion 200 of the present embodiment, the inner diameter of the tapered portion 201 and the inner diameter of the large diameter portion 202 are substantially constant.

The second connector 290 is, for example, a member used by the operator to hold the dilator 2. The second connector 290 has a connection portion 291 and a grip portion 292 from the distal end side to the proximal end side. The connecting portion 291 is a cylindrical member, and an internal thread for screwing with the connecting portion 193 of the first connector 190 of the catheter 1 is formed on the inner peripheral surface of the cylinder. The connection portion 291 is attached to the grip portion 292 so as to be rotatable in the circumferential direction. The grasping portion 292 is a cylindrical member, and a plurality of grooves are formed on the outer peripheral surface of the cylinder. Note that the connection portion 291 and the grip portion 292 may be integrally molded.

In the dilator 2, the lumen of the body portion 200 and the lumen of each member of the second connector 290 communicate with each other to form a guidewire lumen 2L. The guidewire lumen 2L is a lumen through which a guidewire is passed through the dilator 2. As shown in FIG. An opening at the distal end of the dilator 2 that communicates the guide wire lumen 2L with the outside is also called a “tip opening 2a”. At the proximal end of the dilator 2, an opening that communicates the guide wire lumen 2L with the outside is also called a "base end opening 2b".

In the dilator 2, the main body part 200 and the second connector 290 can be made of known resin materials such as fluororesin, polyamide, and polyester. Here, the material of the dilator 2 is preferably selected such that the elastic modulus of the catheter 1 is smaller than the elastic modulus of the dilator 2 . As the elastic modulus of the catheter 1 and the dilator 2, the elastic modulus in the linear region among the test results obtained according to the "breaking strength measurement method" defined in JIS T 3268 may be adopted. In addition, since the assembled

dilator kits

1 and 2 are used in vitro, the step of immersion in an aqueous solution in the "breaking strength measurement method" defined in JIS T 3268 is omitted. The elastic modulus of the hollow shaft portion 100 may be regarded as the "elastic modulus of the catheter 1", and the elastic modulus of the main body portion 200 may be regarded as the "elastic modulus of the catheter 1". When the material constituting the hollow shaft portion 100 and the main body portion 200 is a single material, the catalog value of the material constituting the hollow shaft portion 100 may be adopted as the elastic modulus of the catheter 1, and the elastic modulus of the dilator 2 may be the main body. Catalog values for the materials that make up part 200 may be employed.

FIG. 2 is an explanatory diagram illustrating the configuration of the dilator kit in the assembled state. In FIG. 2, illustration of the guide wire lumen 2L (lumen) of the dilator 2 is omitted. FIG. 3 is an explanatory diagram illustrating the cross-sectional configuration of the distal end side of FIG. 2 . The longitudinal section shown in FIG. 3 is a longitudinal section including the axis O. As shown in FIG. Using FIGS. 2 and 3, the method of using the

dilator kits

1 and 2 and the difference between the separated state and the assembled state will be described.

When using the

dilator kits

1 and 2, the operator inserts the distal end of the dilator 2 into the device lumen 1L (lumen) of the catheter 1 from the proximal end opening 1b of the catheter 1, and inserts the dilator 2 into the device lumen 1L. to protrude the tip of the dilator 2 from the tip opening 1 a of the catheter 1 . In this state, the operator rotates the connecting portion 291 of the dilator 2 in the circumferential direction (black arrow in FIG. 2) to screw the connecting portion 193 of the catheter 1 and the connecting portion 291 of the dilator 2 together. As this screwing continues, the proximal end portion of the hollow shaft portion 100 of the catheter is engaged with the inner peripheral surface of the distal end portion of the hollow shaft portion 100 of the catheter 1 and the outer peripheral surface of the tapered portion 201 of the dilator 2. is pulled toward the proximal end together with the connector 190, the proximal engaging portion 12 and the proximal engaged portion 22 are engaged with each other while the catheter 100 is stretched in the longitudinal direction. Then, as shown in FIG. 2 , the dilator 2 is housed in the device lumen 1L (lumen) of the catheter 1 . Hereinafter, this state is also referred to as an "assembled state".

In the assembled state, as shown in FIGS. 2 and 3, the inner peripheral surface of the distal end portion of the hollow shaft portion 100 of the catheter 1 and the outer peripheral surface of the tapered portion 201 of the dilator 2 are engaged. Here, a portion where the distal end side of the catheter 1 engages with the distal end side of the dilator 2 is referred to as a "distal side engaging portion 11". In the examples of FIGS. 2 and 3, the inner peripheral surface of the distal end portion of the hollow shaft portion 100 of the catheter 1 functions as the distal end side engaging portion 11 . Similarly, the portion where the distal end side of the dilator 2 engages with the distal end side engaging portion 11 of the catheter 1 is referred to as "the distal end side engaged portion 21". In the example of FIGS. 2 and 3, the outer peripheral surface of the tapered portion 201 of the dilator 2 functions as the tip side engaged portion 21 .

In addition, in the assembled state, as shown in FIG. 2, the outer peripheral surface of the first connector 190 (specifically, the connecting portion 193) of the catheter 1 and the second connector 290 (specifically, the connecting portion 291) of the dilator 2 are connected to each other. is engaged with the inner peripheral surface of the Here, the portion where the proximal side of the catheter 1 engages with the proximal side of the dilator 2 is called a "basic side engaging portion 12". In the example of FIG. 2 , the outer peripheral surface of the first connector 190 of the catheter 1 functions as the proximal side engaging portion 12 . Similarly, the portion where the proximal side of the dilator 2 engages with the proximal side engaging portion 12 of the catheter 1 is referred to as "the proximal side engaged portion 22". In the example of FIG. 2 , the inner peripheral surface of the second connector 290 of the dilator 2 functions as the proximal side engaged portion 22 .

Here, in the separated state shown in FIG. 1, the length in the longitudinal direction (X-axis direction) from the distal end side engaging portion 11 to the proximal end side engaging portion 12 of the catheter 1 is L0. In the separated state shown in FIG. 1, the length in the longitudinal direction (X-axis direction) from the distal end side engaged portion 21 to the proximal side engaged portion 22 of the dilator 2 is La. At this time, the length La between the distal-side engaged portion 21 and the proximal-side engaged portion 22 is greater than the length L0 between the distal-side engaging portion 11 and the proximal-side engaging portion 12. is also long (separation state shown in FIG. 1: La>L0).

Therefore, in the assembled state shown in FIG. 2, mainly the hollow shaft portion 100 of the catheter 1 is elongated in the longitudinal direction indicated by the white arrow. Let L1 be the length in the longitudinal direction (X-axis direction) from the distal end side engaging portion 11 to the proximal end side engaging portion 12 of the catheter 1 in the assembled state. At this time, the length L1 between the distal-side engaging portion 11 and the proximal-side engaging portion 12 in the assembled state and the distance between the distal-side engaging portion 11 and the proximal-side engaging portion 12 in the separated state are The difference (L1-L0) from the length L0 is in the range of 1 mm or more and 30 mm or less. Further, the difference (L1-L0) between the length L1 in the assembled state and the length L0 in the separated state is more preferably in the range of 5 mm or more and 15 mm or less. In the example of FIG. 2, the difference (L1-L0) between the length L1 in the assembled state and the length L0 in the separated state is approximately 10 mm. The length L1 in the assembled state corresponds to the "first length", and the length L0 in the separated state corresponds to the "second length".

Furthermore, as shown in FIG. 3, in the vertical cross section of the hollow shaft portion 100 of the catheter 1, the acute angle formed by the outer peripheral surface of the tip tapered portion 101 and the outer peripheral surface of the large diameter portion 102 is defined as a first acute angle θ1. In the same longitudinal section, the acute angle formed by the inner peripheral surface of tip tapered portion 101 and the outer peripheral surface of large diameter portion 102 is defined as a second acute angle θ2. At this time, the first acute angle θ1 is larger than the second acute angle θ2 (FIG. 3: θ1>θ2). By setting the first acute angle .theta.1 and the second acute angle .theta.2 to such a magnitude relationship, the thickness of the tip taper portion 101 can be gradually reduced from the base end side to the tip end side. In other words, the thickness T1 at the distal end portion of the distal tapered portion 101 can be made thinner than the thickness T2 at the proximal end portion of the distal tapered portion 101 .

FIG. 4 is a diagram showing how the dilator kit of this embodiment is inserted into a living tissue. The dilator kit is pushed along a guide wire (not shown) whose distal end portion has been previously inserted into the living tissue, and is inserted into the living tissue. According to the first embodiment, in the separated state in which the catheter 1 and the dilator 2 are separated, the length La between the distal-side engaged portion 21 and the proximal-side engaged portion 22 of the dilator 2 is It is longer than the length L0 between the proximal side engaging portions 12 of the catheter 1 (separated state shown in FIG. 1: La>L0). Therefore, as shown in FIGS. 2 and 4, in the assembled state in which the dilator 2 is accommodated in the device lumen 1L of the catheter 1, the distal end side engaging portion 11 and the distal end side engaging portion 11 are connected while the catheter 1 is stretched in the longitudinal direction. The distal side engaged portion 21 is engaged, and the proximal side engaging portion 12 and the proximal side engaged portion 22 are engaged. Thus, in the

dilator kits

1 and 2 of the present embodiment, the catheter 1 is already stretched in the assembled state. For this reason, as shown in FIG. 4, when the tip of the dilator 2 is pressed against the skin 301 in order to insert the catheter 1 into the living tissue, the catheter 1 receives a pushing force from the hand 302. elongation in the pushing direction (longitudinal direction, the direction of the black arrow in FIG. 4) can be suppressed. 2 and 4, the distal engaging portion 11 and the distal engaged portion 21 are engaged, and the proximal engaging portion 12 and the proximal engaged portion are engaged. 22 is engaged, it is possible to suppress the occurrence of an event in which the dilator 2 receives resistance from the skin 301 and is retracted toward the proximal side within the catheter 1 . As a result, in the

dilator kits

1 and 2 of the first embodiment, the catheter 1 can be easily inserted into living tissue.

Further, according to the first embodiment, the first length L1 between the distal end side engaging portion 11 and the proximal end side engaging portion 12 of the catheter 1 in the assembled state and the distal end side of the catheter 1 in the separated state The difference between the second length L0 between the engaging portion 11 and the proximal side engaging portion 12 (first length L1 - second length L0) is within the range of 1 mm or more and 30 mm or less. Therefore, it is possible to suppress the expansion of the catheter 1 in the pushing direction when receiving the pushing force from the hand 302, and suppress the excessive expansion of the catheter 1 when changing from the separated state to the assembled state. Furthermore, if the difference between the first length L1 and the second length L0 (the first length L1 - the second length L0) is within the range of 5 mm or more and 15 mm or less, the pushing force from the hand 302 can be The extension of the catheter 1 in the pushing direction when it receives it can be further suppressed, and the excessive extension of the catheter 1 when changing from the separated state to the assembled state can be further suppressed.

Furthermore, according to the first embodiment, since the elastic modulus of the catheter 1 is smaller than that of the dilator 2, it is possible to improve the deliverability of the catheter 1 in the biological lumen and insert the dilator 2 into the skin 301. (more specifically, insertion into the skin hole through which the guide wire is inserted) and dilation of the skin 301 by the dilator (more specifically, expansion of the skin hole through which the guide wire is inserted) are facilitated.

Furthermore, according to the first embodiment, the inner peripheral surface of the distal end portion of the hollow shaft portion 100 of the catheter 1 and the outer peripheral surface of the tapered portion 201 of the dilator 2 are engaged, so that the distal end portion of the hollow shaft portion 100 The inner peripheral surface of the tapered portion 201 functions as the tip-side engaging portion 11 , and the outer peripheral surface of the tapered portion 201 functions as the tip-side engaged portion 21 . For this reason, the lumen (device lumen 1L) generally provided in the catheter 1 and the tapered structure on the distal end side generally provided in the dilator 2 are used to achieve the distal end engaging portion 11 and the distal end. An engagement structure with the side engaged portion 21 can be realized. Furthermore, according to the first embodiment, the outer peripheral surface of the first connector 190 of the catheter 1 and the inner peripheral surface of the second connector 290 of the dilator 2 are engaged, so that the outer peripheral surface of the first connector 190 is It functions as the proximal side engaging portion 12 , and the inner peripheral surface of the second connector 290 functions as the proximal side engaged portion 22 . Therefore, by using the

connectors

190 and 290 that are generally provided in the catheter 1 and the dilator 2, the engagement structure between the proximal side engaging portion 12 and the proximal side engaged portion 22 can be realized. .

Furthermore, according to the first embodiment, in the longitudinal section of the hollow shaft portion 100 of the catheter 1, the first acute angle θ1 formed by the outer peripheral surface of the tip taper portion 101 and the outer peripheral surface of the large diameter portion 102 is the tip taper portion It is larger than the second acute angle θ2 formed by the inner peripheral surface of 101 and the outer peripheral surface of large diameter portion 102 (FIG. 3: θ1>θ2). Therefore, the thickness of the tip tapered portion 101 of the catheter 1 can be gradually reduced from the base end to the tip end. As a result, the distal end side of the distal taper portion 101 can be configured more flexibly than the proximal end side, and the step ST (FIG. 3) between the distal end of the catheter 1 and the dilator 2 in the assembled state can be reduced.

FIGS. 5 and 6 are diagrams showing how the dilator kit of the comparative example is inserted into living tissue. The upper balloon in FIG. 5 shows the change in state of the dilator kit of the comparative example as it is pushed. A comparative dilator kit includes a catheter 1x and a dilator 2x. Catheter 1x is a conventional guiding catheter that does not have distal tapered portion 101, distal engaging portion 11, and proximal engaging portion 12. FIG. The dilator 2x is a conventional dilator that does not have a distal side engaged portion 21 and a proximal side engaged portion 22. As shown in FIG. In the example of FIG. 5, the dilator 2x has a small-diameter portion, an enlarged-diameter portion, a large-diameter portion, and a reduced-diameter portion from the distal end side to the proximal end side.

In the dilator kit of the comparative example, when the dilator 2x is accommodated in the lumen of the catheter 1x, as shown by the solid line in the upper balloon in FIG. is placed along the tip of the In this state, in order to insert the catheter 1x into the living tissue, when the tip of the dilator 2x is pressed against the skin 301 and a pushing force is applied from the hand 302, the catheter 1x pushes in the pushing direction (longitudinal direction, shown in FIG. 5). direction of the black arrow), or the dilator 2x receives resistance from the skin 301 and retracts toward the proximal side within the catheter 1x (in other words, the dilator 2x moves in the direction opposite to the black arrow in FIG. 5). ) occurs. As a result, the catheter 1x and the dilator 2x assume the positional relationship shown by the dashed line in FIG. 5, and the catheter 1x is not inserted into the skin 301 by the same length as the length of the catheter 1x pushed by the operator. In addition, due to the change in the positional relationship due to the pushing, the step ST (upper part of FIG. 5) between the tip of the catheter 1x and the dilator 2x increases. As a result, it was difficult to insert the catheter 1x into the living tissue with the dilator kit of the comparative example.

Also, consider a case where the pushing length of the catheter 1x is made longer than in FIG. 5 in order to insert the catheter 1x into the living tissue. In such a case, as shown in FIG. 6, the more proximal side of the catheter 1x is gripped with a hand 302. FIG. However, as shown in FIG. 6, when the proximal end side of the catheter 1x is gripped with a hand 302, the flexible catheter 1x and dilator 2x are flexed and force is not transmitted. Therefore, when applying a pushing force to the catheter 1x and the dilator 2x, it is necessary to grasp the vicinity of the tip of the catheter 1x as shown in FIG. I know there is.

<Second embodiment>
FIG. 7 is an explanatory diagram illustrating the configuration of the dilator kit of the second embodiment. Similar to FIG. 3, FIG. 7 shows a longitudinal section including the axis O of the distal end side of the dilator kit in the assembled state. An enlarged view of a portion surrounded by a dashed circle frame is shown in the upper balloon of FIG. The

dilator kit

1, 2A of the second embodiment includes a dilator 2A instead of the dilator 2 in the configuration described in the first embodiment.

A main body portion 200A of the dilator 2A has a tip-side engaged portion 21A instead of the tip-side engaged portion 21, a tapered portion 201A instead of the tapered portion 201, and a thick portion instead of the large-diameter portion 202. It has a diameter portion 202A. At the tip of the large-diameter portion 202A, a step is formed in which the thick portion protrudes such that the front and rear outer diameters are different. In the assembled

dilator kit

1, 2A of the second embodiment, the inner peripheral surface of the distal end portion of the hollow shaft portion 100 of the catheter 1 and the step formed on the outer peripheral surface of the large diameter portion 202A of the dilator 2A are different. They are engaged (inside the upper balloon in FIG. 7). That is, in the dilator 2A, the step formed on the outer peripheral surface of the large-diameter portion 202A functions as the tip-side engaged portion 21A.

As described above, the configuration of the distal end side engaged portion 21A can be changed in various ways, and it does not have to be formed on the outer peripheral surface of the tapered portion 201A. Also, the distal end side engaged portion 21A may have a configuration different from the configuration described in FIG. good too. With the

dilator kits

1 and 2A of the second embodiment as described above, the same effects as those of the above-described first embodiment can be obtained. It should be noted that the inner peripheral surface of the distal end portion of the shaft 100 of the catheter 1 may be provided with a stepped portion that engages with the stepped portion of the distal side engaged portion 21A.

<Third Embodiment>
FIG. 8 is an explanatory diagram illustrating the configuration of the dilator kit of the third embodiment. Similar to FIG. 3, FIG. 8 shows a longitudinal section including the axis O of the distal end side of the dilator kit in the assembled state. The

dilator kits

1B and 2B of the third embodiment have a catheter 1B in place of the catheter 1 and a dilator 2B in place of the dilator 2 in the configuration described in the first embodiment.

A hollow shaft portion 100B of the catheter 1B has a distal end side engaging portion 11B instead of the distal end side engaging portion 11, does not have the distal end tapered portion 101 described in the first embodiment, and has a large diameter portion 102. It has a large-diameter portion 102B instead. At the tip of the large-diameter portion 102B, a protrusion is formed in which the inner peripheral surface protrudes inward. A main body portion 200B of the dilator 2B has a tip-side engaged portion 21B instead of the tip-side engaged portion 21, a tapered portion 201B instead of the tapered portion 201, and a thick portion instead of the large-diameter portion 202. It has a diameter portion 202B. At the tip of the large-diameter portion 202B, a concave portion is formed in which the thick portion is recessed so that the outer diameter is smaller than that of other portions. In the assembled state, the

dilator kits

1B and 2B of the third embodiment have convex portions formed on the inner peripheral surface of the hollow shaft portion 100B of the catheter 1B and concave portions formed on the outer peripheral surface of the main body portion 200B of the dilator 2B. , are engaged. That is, in the catheter 1B, the convex portion formed on the inner peripheral surface of the large diameter portion 102B functions as the distal end side engaging portion 11B, and in the dilator 2B, the concave portion formed on the outer peripheral surface of the large diameter portion 202B functions as the distal end side. It functions as the engaged portion 21B.

As described above, the configurations of the distal end side engaging portion 11B and the distal end side engaged portion 21B can be modified in various ways, and may be realized by an uneven engagement structure. In the example of FIG. 8, the convex portion is formed on the side of the catheter 1B and the concave portion is formed on the side of the dilator 2B, but these may be reversed. In addition, although the catheter 1B is configured without the tip tapered portion 101, it has the tip tapered portion 101, and the tip end side engagement is realized by the uneven engagement structure on the inner peripheral surface of the tip taper portion 101. A configuration including the portion 11B may be employed. With the

dilator kits

1B and 2B of the third embodiment as described above, the same effects as those of the above-described first embodiment can be obtained.

<Fourth Embodiment>
FIG. 9 is an explanatory diagram illustrating the configuration of the dilator kit of the fourth embodiment. Similar to FIG. 3, FIG. 9 shows a longitudinal section including the axis O of the distal end side of the dilator kit in the assembled state. The

dilator kit

1, 2C of the third embodiment includes a dilator 2C instead of the dilator 2 in the configuration described in the first embodiment.

In the dilator 2C, the frictional force imparting means 23 is provided on the outer peripheral surface of the tapered portion 201 of the main body portion 200 and on the portion that functions as the tip side engaged portion 21 . The frictional force application means 23 is a member or portion for generating a frictional force with the distal end side engaging portion 11 (that is, the inner peripheral surface of the distal end portion of the hollow shaft portion 100). As the frictional force applying means 23, for example, a ring member made of silicon or rubber can be used. Further, the frictional force imparting means 23 may be an uneven surface provided on the outer peripheral surface of the tapered portion 201 . The concave-convex processed surface can be realized, for example, by processing the outer peripheral surface of the tapered portion 201 by well-known laser processing or the like.

Thus, the configuration of the dilator 2C can be modified in various ways, and may have other configurations such as the frictional force imparting means 23 described in FIG. The frictional force imparting means 23 is provided on the side of the distal end engaging portion 11 (that is, on the inner peripheral surface side of the catheter 1), not on the distal end side engaged portion 21 side (that is, on the outer peripheral surface side of the dilator 2C). may With the

dilator kits

1 and 2C of the fourth embodiment as described above, the same effects as those of the above-described first embodiment can be obtained. In addition, according to the

dilator kits

1 and 2C of the fourth embodiment, it is possible to further suppress changes in relative position between the catheter 1 and the dilator 2C when receiving a pushing force from a hand in the assembled state. , the catheter 1 can be more easily inserted into the living tissue.

<Fifth Embodiment>
FIG. 10 is an explanatory diagram illustrating the configuration of the dilator kit of the fifth embodiment. FIG. 10 shows a longitudinal section including the axis O of the proximal side of the dilator kit in the assembled state. The

dilator kits

1D and 2D of the fifth embodiment have a catheter 1D instead of the catheter 1 and a dilator 2D instead of the dilator 2 in the configuration described in the first embodiment.

A first connector 190D of the catheter 1D has a proximal side engaging portion 12D instead of the proximal side engaging portion 12, and a connecting portion 193D instead of the connecting portion 193. The connecting portion 193D is a tubular member, and a columnar projection t protruding from the outer peripheral surface is provided on the outer peripheral surface of the base end portion of the tube. The second connector 290D of the dilator 2D has a proximal side engaged portion 22D instead of the proximal side engaged portion 22, and a connecting portion 291D instead of the connecting portion 291. As shown in FIG. The connecting portion 291D is a tubular member, and an L-shaped groove m is formed in the inner peripheral surface of the tubular member.

In order to bring the

dilator kits

1D and 2D of the fifth embodiment into an assembled state, the following operations are performed. First, the operator inserts the protrusion t of the first connector 190D of the catheter 1D into the groove m of the second connector 290D of the dilator 2D, and moves the protrusion t along the groove m toward the proximal end. push in. Thereafter, the operator rotates the second connector 290D together with the connecting portion 291D fixed thereto at the abutting portion of the groove m, thereby fitting the projection t into the depth of the L-shaped groove m. Thus, in the

dilator kits

1D and 2D of the fifth embodiment, in the assembled state, the groove m formed in the inner peripheral surface of the second connector 290D of the dilator 2D and the outer peripheral surface of the first connector 190D of the catheter 1D The formed projection t and are engaged. That is, in the catheter 1D, the protrusion t formed on the outer peripheral surface of the connecting portion 193D functions as the proximal side engaging portion 12D, and in the dilator 2D, the groove m formed on the inner peripheral surface of the connecting portion 291D serves as the proximal end. It functions as the side engaged portion 22D.

As described above, the configurations of the proximal side engaging portion 12D and the proximal side engaged portion 22D can be variously modified, and are realized with a configuration different from the so-called luer lock structure described in the first embodiment. good too. In the example of FIG. 10, the grooves m are formed on the side of the dilator 2D and the projections t are formed on the side of the catheter 1D, but these may be reversed. Also, instead of the groove m, a notch formed in a cylindrical member can be used. With the

dilator kits

1D and 2D of the fifth embodiment as described above, the same effects as those of the above-described first embodiment can be obtained.

<Sixth embodiment>
FIG. 11 is an explanatory diagram illustrating the configuration of the dilator kit of the sixth embodiment. Similar to FIG. 3, FIG. 11 shows a longitudinal section including the axis O of the distal end side of the dilator kit in the assembled state. The

dilator kits

1E and 2 of the sixth embodiment have a catheter 1E instead of the catheter 1 in the configuration described in the first embodiment.

The catheter 1E has a hollow shaft portion 100E instead of the hollow shaft portion 100. In the longitudinal section shown in FIG. 11, the hollow shaft portion 100E defines an acute angle formed between the outer peripheral surface of the distal end tapered portion 101 and the outer peripheral surface of the large diameter portion 102 as a first acute angle θ1, and the inner peripheral surface of the distal end tapered portion 101 and the thick portion. The acute angle formed with the outer peripheral surface of the diameter portion 102 is equal to the second acute angle .theta.2 (FIG. 11: .theta.1=.theta.2). Therefore, the thickness of the tip tapered portion 101 of the catheter 1E is generally uniform from the base end side to the tip end side. In other words, the thickness T1 at the distal end portion of the distal tapered portion 101 and the thickness T2 at the proximal end portion of the distal tapered portion 101 are substantially equal. As described above, the configuration of the catheter 1E can be changed in various ways, and the thickness of the tip tapered portion 101 may be made substantially uniform. With the

dilator kits

1E and 2 of the sixth embodiment as described above, the same effects as those of the above-described first embodiment can be obtained.

<Seventh embodiment>
FIG. 12 is an explanatory diagram illustrating the configuration of the dilator kit of the seventh embodiment. Similar to FIG. 3, FIG. 12 shows a longitudinal section including the axis O of the distal end side of the dilator kit in the assembled state. The

dilator kits

1F, 2 of the seventh embodiment have a catheter 1F instead of the catheter 1 in the configuration described in the first embodiment.

The catheter 1F has a hollow shaft portion 100F instead of the hollow shaft portion 100. Hollow shaft portion 100F, in the vertical cross section shown in FIG. The acute angle formed with the outer peripheral surface of the diameter portion 102 is smaller than the second acute angle θ2 (FIG. 12: θ1<θ2). Therefore, the thickness of the tip tapered portion 101 of the catheter 1F gradually increases from the base end to the tip end. In other words, the thickness T1 at the distal end portion of the distal tapered portion 101 can be made thicker than the thickness T2 at the proximal end portion of the distal tapered portion 101 . As described above, the configuration of the catheter 1E can be changed in various ways, and the thickness of the tapered portion 101 may be gradually increased from the proximal side to the distal side. With the

dilator kits

1F and 2 of the seventh embodiment as described above, the same effects as those of the above-described first embodiment can be obtained.

<Modified example of the present embodiment>
The present invention is not limited to the above-described embodiments, and can be implemented in various aspects without departing from the scope of the invention. For example, the following modifications are possible.

[Modification 1]
In the above first to seventh embodiments, an example of the configuration of the dilator kit has been shown. However, various modifications are possible in the configuration of the dilator kit. For example, the length L1 between the distal side engaging portion 11 and the proximal side engaging portion 12 in the assembled state and the length between the distal side engaging portion 11 and the proximal side engaging portion 12 in the separated state The difference (L1-L0) from the height L0 may be less than 1 mm and may be greater than 30 mm. For example, the elastic modulus of the catheter may be greater than the elastic modulus of the dilator. For example, the modulus of elasticity of the catheter and the modulus of elasticity of the dilator may be the same.

[Modification 2]
In the above-described first to seventh embodiments, examples of configurations of the

catheters

1, 1B, 1D, 1E, and 1F are shown. However, various modifications of the configuration of the catheter 1 are possible. For example, tip taper portion 101 may be omitted. For example, the distal end portion of the hollow shaft portion 100 may be provided with a radiopaque marker portion. For example, the catheter 1 may be configured as a catheter other than a guiding catheter. In this case, the catheter 1 may be configured as a multi-lumen catheter with multiple lumens. For example, the distal end side and the proximal end side of the hollow shaft portion 100 may be made of different materials and have different elastic moduli. In this case, it is preferable that at least the distal end side of the hollow shaft portion 100 have a smaller elastic modulus than the dilator 2 .

[Modification 3]
In the first to seventh embodiments, an example of the configuration of the

dilators

22A, 2B, 2C and 2D has been shown. However, the configuration of the dilator 2 can be modified in various ways. For example, a small-diameter portion may be provided on the distal end side of the tapered portion 201, and an enlarged-diameter portion or a second large-diameter portion larger than the large-diameter portion 202 may be provided on the proximal end side of the large-diameter portion 202. may be provided. For example, the distal end side and the proximal end side of the body portion 200 may be made of different materials and have different elastic moduli. In this case, it is preferable that at least the distal end side of the body portion 200 has a higher elastic modulus than the catheter 1 .

[Modification 4]
Configurations of the

catheters

1, 1B, 1D, 1E, 1F and the

dilators

22A, 2B, 2C, 2D of the first to seventh embodiments, and the

catheters

1, 1B, 1D, 1E, 1F and the dilators 22A of the modified examples 1 to 3 , 2B, 2C, and 2D may be combined as appropriate. For example, the distal side configuration described in any one of the second, third, fourth, sixth and seventh embodiments may be combined with the proximal side configuration described in the fifth embodiment. For example, the catheters of the second to fifth embodiments may be configured to have the first acute angle θ1 and the second acute angle θ2 described in either the sixth or seventh embodiment.

The catheter of the first to seventh embodiments is a dilator kit comprising a catheter having a lumen and a dilator, wherein the dilator is accommodated in the lumen of the catheter in an assembled state, wherein the catheter and the dilator are Based on the separated separated state, the catheter in the assembled state is stretched in its length direction (for example, within the range of 1 mm or more and 30 mm or less, preferably 5 mm or more and 15 mm or less). , supported by the dilator. Therefore, it is possible to suppress elongation of the catheter in the pushing direction (longitudinal direction) when receiving a pushing force from the hand when inserting the catheter into the living tissue. As a result, the catheter of the assembled dilator kit can be easily inserted into living tissue.

Although the present aspect has been described above based on the embodiments and modifications, the above-described embodiments are intended to facilitate understanding of the present aspect, and do not limit the present aspect. This aspect may be modified and modified without departing from the spirit and scope of the claims, and this aspect includes equivalents thereof. Also, if the technical features are not described as essential in this specification, they can be deleted as appropriate.

1, 1B, 1D, 1E, 1F... catheter 1x... catheter (comparative example)
22A, 2B, 2C, 2D... dilator 2x... dilator (comparative example)
REFERENCE SIGNS

LIST

11, 11B... Tip

side engaging portion

12, 12D... Base end

side engaging portion

21, 21A, 21B... Tip side engaged

portion

22, 22D... Base end side engaged portion 23... Frictional force imparting means 100, DESCRIPTION OF

SYMBOLS

100B, 100E, 100F... Hollow shaft part 101...

Tip taper part

102, 102B...

Large diameter part

190, 190D... First connector 191... Accommodating part 192...

Blade part

193, 193D...

Connection part

200, 200A, 200B...

Main body part

201, 201A, 201B... Taper part 202202A, 202B...

Large diameter part

290, 290D...

Second connector

291, 291D... Connection part 292... Grip part

Claims

A dilator kit comprising a catheter having a lumen and a dilator, wherein the dilator is accommodated in the lumen of the catheter in an assembled state,
The catheter, in the assembled state,
Having a distal side engaging portion and a proximal side engaging portion that engage with the dilator, respectively;
The dilator, in the assembled state,
a tip-side engaged portion that engages with the tip-side engaging portion of the catheter;
a proximal-side engaged portion that engages with the proximal-side engaging portion of the catheter;
In the separated state in which the catheter and the dilator are separated, the length between the distal end side engaged portion and the proximal side engaged portion of the dilator is equal to the distal end side engaging portion of the catheter. A dilator kit longer than the length between the base end side engaging portion.
The dilator kit according to claim 1,
a length between the distal end side engaging portion and the proximal end side engaging portion of the catheter in the assembled state is defined as a first length;
When the length between the distal side engaging portion and the proximal side engaging portion of the catheter in the separated state is defined as a second length,
A dilator kit, wherein the difference between the first length and the second length is in the range of 1 mm or more and 30 mm or less.
The dilator kit according to claim 2,
A dilator kit, wherein the difference between the first length and the second length is in the range of 5 mm or more and 15 mm or less.
The dilator kit according to any one of claims 1 to 3,
A dilator kit, wherein the elastic modulus of the catheter is less than the elastic modulus of the dilator.
The dilator kit according to any one of claims 1 to 4,
The catheter has a hollow shaft,
The dilator has an elongated main body,
The main body portion of the dilator is provided with a tapered portion whose outer diameter gradually increases from the distal end side to the proximal end side,
In the assembled state, the inner peripheral surface of the distal end portion of the hollow shaft portion is engaged with the outer peripheral surface of the tapered portion, so that the inner peripheral surface of the distal end portion of the hollow shaft portion is engaged with the distal end side. and the outer peripheral surface of the tapered portion functions as the distal end side engaged portion.
The dilator kit according to claim 5,
The catheter further has a first connector provided at the proximal end of the hollow shaft,
The dilator further has a second connector provided at the proximal end of the main body,
In the assembled state, the outer peripheral surface of the first connector and the inner peripheral surface of the second connector are engaged, so that the outer peripheral surface of the first connector functions as the proximal side engaging portion, The dilator kit, wherein the inner peripheral surface of the second connector functions as the proximal side engaged portion.
The dilator kit according to claim 5 or claim 6,
The hollow shaft portion of the catheter includes:
a distal tapered portion in which both the outer diameter and the inner diameter gradually expand from the distal end side to the proximal end side;
a large-diameter portion having a substantially constant outer diameter disposed closer to the proximal end than the distal end tapered portion;
In the longitudinal section of the hollow shaft portion,
An acute angle formed by an outer peripheral surface of the tip tapered portion and an outer peripheral surface of the large-diameter portion is defined as a first acute angle,
When the acute angle formed by the inner peripheral surface of the tip tapered portion and the outer peripheral surface of the large-diameter portion is defined as a second acute angle,
The dilator kit, wherein the first acute angle is greater than the second acute angle.