Expansion tool

Abstract

A dilator serving as an expansion tool comprises: a shaft 2 that is inserted into the body via an endoscope, is provided with a tapered hole expansion part 21 on the distal end side, and is provided with a tubular part 22 on the proximal end side; a first lumen 41 that is provided in the shaft 2 and that has a first opening 411 at the distal end; and a second lumen 42, which is different from the first lumen 41, that is provided in the shaft 2 and that has a second opening 421 at the distal end. The first opening 411 is provided at the distal end of the hole expansion part 21, and the second opening 421 is provided on the side surface of the shaft 2 further toward the proximal end relative to the first opening 411. The length d of the second opening 421 along the extension direction of the shaft 2 is greater than the diameter R of the tubular part 22 in the radial direction perpendicular to the extension direction.

Description

Dilator

[0001] The present disclosure relates to dilators, also called dilators.

[0002] Patent Document 1 discloses a dilator that assists in inserting two guide wires into a blood vessel. This dilator includes a first lumen into which a first guide wire previously inserted into the blood vessel through a puncture needle is inserted, and a second lumen into which a second guide wire is inserted in a state where the dilator is inserted into the blood vessel through the first lumen and the first guide wire. After the dilator is removed, two guide wires, the first guide wire and the second guide wire, remain in the blood vessel and assist in inserting other medical devices such as catheters into the blood vessel.

[0003] Japanese Patent Application Laid-Open No. 2016-209319

[0004] In the dilator of Patent Document 1, the second guide wire exits "obliquely" from the opening (7a) of the second through hole (7) formed on the surface of the tapered portion (9). The opening (7a) itself is small, and there are unstable portions such as thin portions that are presumably due to processing reasons at the edge of the opening (7a), which may hinder the insertion and removal of the second guide wire.

[0005] The present disclosure has been made in view of such a situation, and an object thereof is to provide a dilator or the like that can improve the insertability and removability of a guide wire or the like.

[0006] To solve the above problems, a dilator according to an aspect of the present disclosure includes a shaft that is inserted into the body via an endoscope, has a tapered hole expansion portion provided on the distal end side, and a tubular portion provided on the proximal end side, a first lumen provided in the shaft and having a first opening at the distal end, and a second lumen provided in the shaft and different from the first lumen having a second opening at the distal end. The first opening is provided at the distal end of the hole expansion portion, the second opening is provided on the side surface of the shaft on the proximal end side of the first opening, and the length of the second opening along the extending direction of the shaft is larger than the diameter of the tubular portion in the radial direction perpendicular to the extending direction.

[0007] According to this embodiment, a guide wire or the like can be easily inserted and removed through a second opening that is longer in the extending direction than the diameter of the tubular portion of the shaft.

[0008] Furthermore, any combination of the above components, as well as any representations thereof converted into methods, apparatus, systems, recording media, computer programs, etc., are also included in this disclosure.

[0009] According to this disclosure, the ease of insertion and removal of guide wires and the like can be improved.

[0010] Figure 4 schematically shows the overall appearance of the dilator. This is a schematic cross-sectional view including the central axis of the tip of the shaft. This schematically shows a cross-section of the shaft. This schematic perspective view shows the appearance of the dilator. This schematic cross-sectional view shows the edge of the initial opening formed into a smooth curved surface after the first step. This schematic shows an example of a manufacturing method for the dilator illustrated in Figure 4. This shows the flow of EUS-HGS as an example of a procedure using the dilator. This shows the flow of EUS-HGS as an example of a procedure using the dilator. This shows the flow of EUS-HGS as an example of a procedure using the dilator. This shows the flow of EUS-HGS as an example of a procedure using the dilator. This shows the flow of EUS-HGS as an example of a procedure using the dilator. This shows the flow of EUS-HGS as an example of a procedure using the dilator.

[0011] The following describes in detail the forms for implementing this disclosure (hereinafter also referred to as embodiments) with reference to the drawings. In the description and / or drawings, identical or equivalent components, members, processes, etc., are denoted by the same reference numerals, and redundant descriptions are omitted. The scale and shape of the illustrated parts are set for convenience to simplify the description and are not to be interpreted restrictively unless otherwise specified. The embodiments are illustrative and do not limit the scope of this disclosure in any way. Not all features or combinations thereof presented in the embodiments are necessarily essential to this disclosure. For convenience, embodiments are presented by breaking them down into components for each function and / or group of functions that realize them. However, one component in an embodiment may actually be realized by a combination of multiple components as separate entities, and multiple components in an embodiment may actually be realized by a single component as a whole. Furthermore, multiple embodiments and modifications may be disclosed in parallel, and any components of each embodiment and / or modification may be combined in any manner as long as they do not interfere with each other's functions.

[0012] Figure 1 schematically shows the overall appearance of a dilator 1 according to an embodiment of the present disclosure. The dilator 1 is, for example, an expander that assists in the insertion of multiple guidewires into the digestive system. As will be described later, the dilator 1 according to this embodiment assists in the insertion of multiple guidewires from the stomach, which is part of the digestive tract, into the intrahepatic bile duct, but the expander according to the present disclosure may also assist in the insertion of multiple guidewires into any other organ (organs other than blood vessels are preferred).

[0013] In this embodiment, the term "dilator" is used for convenience and in a broad sense, encompassing, but not limiting, medical devices commonly referred to as "dilators" in the medical field. As will be described later, the dilator 1 according to this embodiment mainly has the function of expanding the insertion site (hole) for the guidewire and the function of passing multiple guidewires through it. However, any medical device capable of performing these main functions is included in the term "dilator" in this embodiment, regardless of its name. For example, a tubular medical device called a cannula or cannula is also included in the term "dilator" in this embodiment when used in a manner that performs the above-mentioned main functions.

[0014] The dilator 1 comprises a tubular shaft 2 and a port portion 3 provided at the base end of the shaft 2. When the dilator 1 is inserted into the body, the tip portion 2D of the shaft 2 is inside the body, and the port portion 3 (and the base end portion 2P of the shaft 2) is outside the body.

[0015] The shaft 2 is a tube extending between a proximal end 2P and a distal end 2D. The flexible shaft 2 can move smoothly along the inner walls of endoscopes and tubular organs (bile ducts in this embodiment) while deforming (being guided) according to their shapes. The distal end 2D of the shaft 2 is provided with a tapered hole expansion section 21 (i.e., the hole expansion section 21 constitutes a part of the distal end 2D). The hole expansion section 21 is provided at the tip of the distal end 2D (i.e., the tip of the entire shaft 2 or the entire dilator 1), and its diameter or size (cross-sectional area) gradually decreases from the proximal end to the distal end. The tip of the hole expansion section 21 is located on the central axis of the shaft 2.

[0016] The pointed hole-expanding portion 21 is inserted into the guidewire insertion hole (for example, a hole made by a puncture needle between the stomach and the intrahepatic bile duct, as described later) to expand the insertion hole. The tip portion 2D of the shaft 2 can enter the organ beyond the insertion hole expanded by the hole-expanding portion 21 (in this embodiment, the intrahepatic bile duct). Thus, the portion of the shaft 2 that can enter the organ beyond the insertion hole expanded by the hole-expanding portion 21 may be defined as the tip portion 2D.

[0017] As will be described later, with the tip 2D of the shaft 2 inside the organ beyond the insertion hole, an additional guidewire (second guidewire) is inserted into the organ through the tip 2D. Furthermore, other medical devices such as stents and catheters can be effectively guided to the target site through the insertion hole expanded by these (multiple) guidewires and the hole expander 21.

[0018] The port portion 3 connected to the base end portion 2P of the shaft 2 includes a first port 31 into which a first guidewire, described later, is inserted, and a second port 32 into which a second guidewire, described later, is inserted. As described later, the first guidewire inserted into the first port 31 communicates with the first port 31 and is guided through a first lumen that penetrates the shaft 2 from the base end portion 2P to the tip portion 2D to a first opening provided at the tip portion 2D. The second guidewire inserted into the second port 32 communicates with the second port 32 and is guided through a second lumen that penetrates the shaft 2 from the base end portion 2P to the tip portion 2D to a second opening provided at the tip portion 2D.

[0019] Figure 2 is a schematic cross-sectional view including the central axis of the tip portion 2D of the shaft 2 (and the central axes of the two lumens 41 and 42, which will be described later). The tip portion 2D of the shaft 2 has the tapered hole expansion portion 21 described above at the tip end, and a tubular portion 22 with a substantially constant diameter or size (cross-sectional area) at the base end. In the following example, the tubular portion 22 (excluding the portion where the second opening 421 described later is provided) is substantially straight, and its cross-sectional shape, with its axial or extending direction (left-right direction in Figure 2) as the normal direction, is assumed to be circular with a substantially constant diameter (i.e., the tubular portion 22 is circular). However, in this disclosure, the diameter of the tubular portion 22 at the tip portion 2D may vary depending on the axial position, as long as it is greater than the diameter of the portion where the second opening 421 is provided, as will be described later. Also, the cross-sectional shape of the tubular portion 22 at the tip portion 2D is not limited to circular and may be elliptical. Furthermore, the cross-sectional shape of the tubular portion 22 at the tip portion 2D may vary between circular and elliptical depending on the axial position.

[0020] Within the shaft 2, a first lumen 41 into which the first guidewire 51 is inserted and a second lumen 42 different from the first lumen 41 into which a second guidewire 52 different from the first guidewire 51 is inserted extend between the base end 2P and the tip end 2D. As described above, the first lumen 41 extends to the base end 2P of the shaft 2 and is connected to the first port 31, and the second lumen 42 extends to the base end 2P of the shaft 2 and is connected to the second port 32.

[0021] The first lumen 41 has a first opening 411 at its tip. The second lumen 42 has a second opening 421 at its tip. The first opening 411 and the second opening 421 are provided at the tip portion 2D of the shaft 2. The second opening 421 is provided on the side surface (bottom surface in Figure 2) of the shaft 2, on the base end side (right side in Figure 2) of the shaft 2, from the first opening 411.

[0022] In the illustrated example, the first opening 411 is located at the tip of the aforementioned hole expansion portion 21 (i.e., the tip portion 2D or the tip of the entire shaft 2). The second opening 421 is provided on the side surface of the tubular portion 22, on the base side of the base end 21P where the tapered shape of the hole expansion portion 21 ends. Preferably, a straight tubular transition portion 22T, which is the tip of the tubular portion 22, exists between the base end 21P of the hole expansion portion 21 and the tip of the second opening 421. By providing the second opening 421 on the side surface of the tubular portion 22 and not on the side surface of the hole expansion portion 21, there is an advantage in that the tapered shape of the hole expansion portion 21 can be effectively utilized along its entire length. In addition, since the tapered shape can be made substantially longer, there is an advantage in that the taper angle can be made gentler, which reduces the burden on the human body. For example, in a case where a second opening 421 is provided on the side surface of the hole expansion portion 21, and the total length of the effectively functioning tapered shape is 10 mm, the total length of the effectively functioning tapered shape can be extended to over 10 mm by moving the second opening 421 to the tubular portion 22.

[0023] Furthermore, the tip of the second opening 421 may substantially coincide with the base end 21P of the hole expansion portion 21, in which case there is no transition portion 22T. Moreover, the tip of the second opening 421 may be located on the tip side of the base end 21P of the hole expansion portion 21, in which case there is also no transition portion 22T. Thus, it is preferable that at least the tip of the second opening 421 is provided on the side surface of the tapered hole expansion portion 21, while the base end of the second opening 421 is provided on the side surface of the straight tubular portion 22. That is, the second opening 421 may be formed spanning the hole expansion portion 21 and the tubular portion 22.

[0024] The first opening 411 and the second opening 421 open in different directions from each other. In the illustrated example, the first opening 411, located at the tip of the hole expansion portion 21, opens in the direction of extension of the shaft 2 (left-right direction in Figure 2). In other words, the direction normal to the opening surface of the first opening 411 substantially coincides with the direction of extension of the shaft 2. The second opening 421, located on the side surface of the shaft 2 (particularly the tubular portion 22), opens in a direction that forms an acute angle θ with the direction of extension of the shaft 2 (i.e., the opening direction of the first opening 411). This acute angle θ is achieved at the tip of the second opening 421 by the inner side wall of the second lumen 42 bending outward at the acute angle θ.

[0025] This acute angle θ may be interpreted as the angle formed by the extending or tangential direction of the first guide wire 51 immediately after it extends from the first opening 411 and the extending or tangential direction of the second guide wire 52 immediately after it extends from the second opening 421, as shown in the figure. That is, if the first guide wire 51 immediately after it exits the first opening 411 and the second guide wire 52 immediately after it exits the second opening 421 extend in different directions that form an acute angle θ, then the first opening 411 and the second opening 421 can be interpreted as opening in different directions that form an acute angle θ. Here, when measuring the acute angle θ formed by the first guide wire 51 and the second guide wire 52, it is preferable that the shaft 2 is positioned horizontally or vertically.

[0026] To achieve this acute angle θ, in the tubular portion 22 on the base end side of the second opening 421, the second lumen 42, which extends in the direction of extension of the shaft 2 similar to the first lumen 41, bends outward (downward or lower left in Figure 2) at the tip of the second opening 421. The second lumen 42 (or the tip of the second opening 421), which is bent at an acute angle θ with respect to the direction of extension of the shaft 2 (i.e., the direction of extension of the first lumen 41), opens obliquely on the side surface of the shaft 2 (especially the tubular portion 22).

[0027] With the above configuration, the first guidewire 51 passing through the first lumen 41 exits the dilator 1 along the extending direction of the shaft 2 from the first opening 411 located at the tip of the hole expansion portion 21. The second guidewire 52 passing through the second lumen 42 exits the dilator 1 along a direction that forms an acute angle θ with the extending direction of the shaft 2 from the second opening 421 located on the side of the shaft 2 (particularly the tubular portion 22). Here, for EUS-HGS and similar procedures described later, the acute angle θ is preferably between 0.5 degrees and 10 degrees, and more preferably between 1 degree and 5 degrees.

[0028] The diameters of the first guidewire 51 and the second guidewire 52 are arbitrary, but as will be described later, it is preferable to use a relatively small diameter for the first guidewire 51, which is inserted into the body first through the puncture needle, and a relatively large diameter for the second guidewire 52, which is inserted into the body later through the dilator 1. For example, a small-diameter guidewire of 0.018 inches, which is common for medical use, can be used as the first guidewire 51, and a large-diameter guidewire of 0.025 inches or 0.035 inches, which is common for medical use, can be used as the second guidewire 52. The diameters of the first guidewire 51 and the second guidewire 52 may be equal (for example, both 0.025 inches), or the diameter of the first guidewire 51 may be larger than the diameter of the second guidewire 52.

[0029] As will be described later, it is preferable that the shaft 2, which is inserted into the body via an endoscope, has contrast-enhancing properties at least at its tip portion 2D. Here, contrast enhancement means the property of being visible in a manner that can be distinguished from other objects in images obtained through any medical imaging technique such as X-ray imaging, magnetic resonance imaging (MRI), or computed tomography (CT). For example, in order to impart contrast enhancement to the shaft 2 in X-ray imaging, iodine compounds, barium compounds, bismuth compounds, gadolinium compounds, gold, platinum-iridium alloy, tungsten, etc., which shield against X-rays, can be mixed into the constituent material of the shaft 2.

[0030] Such contrast-enhancing properties are particularly useful when guiding the hole expansion portion 21, located at the tip of the entire shaft 2, to a desired location (for example, the aforementioned insertion hole). Therefore, contrast-enhancing properties are provided to at least a part, preferably the entire, of the hole expansion portion 21. On the other hand, while it is preferable that the tubular portion 22 of the shaft 2, located at the proximal end of the hole expansion portion 21, has minimal contrast-enhancing properties, it is not necessarily required that the entire portion has contrast-enhancing properties, and it may not have any contrast-enhancing properties at all.

[0031] Furthermore, the dilator 1 may be provided with a contrast marker 6 that has different contrast properties than the shaft 2 and indicates the position of the second aperture 421 when contrast is applied. Here, "the contrast marker 6 has different contrast properties than the shaft 2" means that in images acquired by any medical imaging technology, the contrast marker 6 is visualized in a manner that is distinguishable from the shaft 2. In order to emphasize the position of the second aperture 421 in the image, it is preferable that the contrast marker 6 has higher contrast properties than the shaft 2.

[0032] For example, when contrast is performed by X-ray imaging, the contrast marker 6 can be given higher contrast properties by increasing the density of X-ray shielding materials such as iodine compounds, barium compounds, bismuth compounds, gadolinium compounds, gold, platinum-iridium alloys, and tungsten in the contrast marker 6 compared to the shaft 2. However, even if the contrast marker 6 has lower contrast properties than the shaft 2, this does not pose a major problem as long as both are distinguishable in the image.

[0033] The contrast marker 6 is preferably positioned between the first opening 411 and the second opening 421 on the shaft 2. As described above, since the second opening 421 opens in a direction that forms an acute angle θ with the extending direction of the shaft 2, the actual position where the tip of the second guidewire 52 exits the dilator 1 diagonally forward is perceived by the operator of the dilator 1, such as a physician, as being closer to the tip than the actual position of the second opening 421. Therefore, by deliberately positioning at least the tip of the contrast marker 6 closer to the tip than the actual tip of the second opening 421, the operator of the dilator 1, such as a physician, can correctly recognize the actual tip position or operating position of the second guidewire 52 using the contrast marker 6, thereby improving the operating accuracy or procedural accuracy of the second guidewire 52.

[0034] As shown in the illustrated example, when a straight tubular transition section 22T exists between the tapered hole expansion section 21 and the second opening 421, it is preferable to provide the contrast marker 6 in the transition section 22T. Although the contrast marker 6 may also be provided in the tapered hole expansion section 21, the difficulty of formation increases (or the accuracy of formation decreases) compared to when it is provided in the straight tubular transition section 22T or the tubular section 22. In particular, when forming the tapered shape of the hole expansion section 21 or when pushing the hole expansion section 21 into the hole to be expanded, there is a risk that the thin surface of the hole expansion section 21 may tear, exposing the contrast marker 6. Therefore, it is preferable to provide the contrast marker 6 in the straight tubular section 22.

[0035] In the illustrated example, the contrast marker 6 is provided on the transition section 22T, but it may also be provided on the tubular section 22 on the proximal end side of the transition section 22T, for example, in an axial position that overlaps with the second opening 421. Even in that case, for the reasons mentioned above, it is preferable to provide the contrast marker 6 as far as possible on the tip side of the second opening 421.

[0036] The contrast marker 6 is preferably provided as far towards the tip as possible on the tubular portion 22 in any manner. For example, the contrast marker 6 may be provided in an annular shape along the inner wall of the first lumen 41 that extends through the tubular portion 22 and the hole expansion portion 21. The contrast marker 6 may be configured as a part of the contrast-enhancing shaft 2 that has contrast properties as described above, with different contrast properties from other parts (preferably a part with higher contrast properties than other parts). When the contrast marker 6 is placed on the surface of the shaft 2, it is necessary to integrate the material that will become the contrast marker 6 with the shaft 2 in any way. However, applying or bonding such a contrast-enhancing material carries the risk of damage due to the step difference with the shaft 2 or detachment due to insufficient adhesion. Therefore, by providing the contrast marker 6 inside the shaft 2, the detachment of the contrast marker 6 can be prevented. However, the contrast marker 6 may also be embedded in the outer circumferential surface of the shaft 2.

[0037] Figure 3 is a cross-sectional view taken along line A-A in Figure 2, schematically showing the cross-section of the shaft 2 (tubular portion 22). The shaft 2 is made of, for example, polyamide, polyamide elastomer, polyurethane elastomer, olefin resin, etc. In order for the dilator 1 to perform its main function of expanding the insertion hole for guide wires, stents, etc., it is preferable that the constituent material of the shaft 2 has relatively high hardness. For example, the preferred range of Shore D hardness as a parameter representing hardness is between 50D and 95D, a more preferred range is between 63D and 75D, and an even more preferred range is between 69D and 72D.

[0038] The cross-section of the shaft 2 is approximately circular for at least 75% of the total length of the tubular portion 22, preferably over its entire length, and its diameter is, for example, 2.45 mm. The first lumen 41 through which the first guide wire 51 with a diameter of 0.018 inches (approximately 0.46 mm) passes, and the second lumen 42 through which the second guide wire 52 with a diameter of 0.025 inches (approximately 0.64 mm) passes, may have different diameters as long as the respective guide wires 51 and 52 can pass through properly, but in the example shown in this figure, they have the same diameter (for example, 0.8 mm). The cross-section of the shaft 2 may also be approximately elliptical over the entire length of the tubular portion 22, and may vary slightly between approximately circular and approximately elliptical.

[0039] The first lumen 41 and the second lumen 42 are positioned offset from the central axis of the shaft 2. As shown in Figure 2, in the hole expansion portion 21 of the second lumen 42 beyond the second opening 421, only the first lumen 41 extends into the shaft 2, and its center is positioned closer to the central axis of the shaft 2 compared to the cross-section A-A in Figure 3.

[0040] The first lumen 41 and the second lumen 42 are provided symmetrically with respect to an X-axis (the left-right axis in FIG. 3), which is a symmetry axis, in a cross-section orthogonal to the axis of the shaft 2. Specifically, the first lumen 41 and the second lumen 42 are provided at positions symmetric with respect to the X-axis. Here, in the illustrated example where both the first lumen 41 and the second lumen 42 are substantially circular, their centers are provided at positions symmetric with respect to the X-axis. In the case where the shapes of the first lumen 41 and the second lumen 42 are different, corresponding representative points such as their centers and centroids are provided at positions symmetric with respect to the X-axis (the same applies to other examples of line-symmetric arrangements described later).

[0041] The first lumen 41 and the second lumen 42 are provided symmetrically with respect to a Y-axis (the up-down axis in FIG. 3), which is a symmetry axis, in a cross-section orthogonal to the axis of the shaft 2. Specifically, the first lumen 41 has a shape symmetric with respect to the Y-axis, and the second lumen 42 has a shape symmetric with respect to the Y-axis. In the illustrated example where both the first lumen 41 and the second lumen 42 are substantially circular, the Y-axis passes through their centers.

[0042] The center of the shaft 2, the center of the first lumen 41, and the center of the second lumen 42 are arranged, for example, on a straight line (on a straight line in the up-down direction in FIG. 3). Also, the first lumen 41 and the second lumen 42 are arranged point-symmetrically with respect to the center of the shaft 2. For example, when the position of the first lumen 41 is set as the "0 o'clock (12 o'clock)" position of a clock, the second lumen 42 is at the "6 o'clock" position.

[0043] In this embodiment, for convenience, terms such as line symmetry and point symmetry are used. However, in the actual dilator 1, it is not required that each lumen such as the first lumen 41 and the second lumen 42 be provided at a strictly line-symmetric position (or line-symmetric shape) and / or point-symmetric position. For example, each lumen may be arranged within a predetermined distance from the intended line-symmetric position and / or point-symmetric position. Specifically, the distance from the intended line-symmetric position and / or point-symmetric position of each lumen may be within 30% of the diameter of the respective lumen, preferably within 20%, and more preferably within 10%.

[0044] Returning to FIG. 2, the second opening 421 of the second lumen 42 through which the second guide wire 52 obliquely passes will be described in detail. The second opening 421 according to the present embodiment is a long hole in the extending direction of the shaft 2 (the left-right direction in FIG. 2). For example, the length d of the second opening 421 along the extending direction of the shaft 2 is larger than the diameter R of the tubular portion 22 (however, the portion where the second opening 421 is not provided) in the radial direction (the up-down direction in FIG. 2) perpendicular to the extending direction. This diameter R may be interpreted as the diameter of the shaft 2 (however, excluding the hole expansion portion 21 and the second opening 421), or may be substantially equal to (or different from) the diameter at the proximal end 21P where the tapered shape of the hole expansion portion 21 ends. Therefore, the length d of the second opening 421 is larger than the diameter R at the proximal end 21P of the hole expansion portion 21.

[0045] Here, the length d of the second opening 421 is defined on the surface of the shaft 2. Specifically, in the contour or closed curve of the second opening 421 that appears on the surface of the shaft 2, the distance along the extending direction between the two points that are farthest apart along the extending direction is the length d of the second opening 421. In the schematic example of FIG. 2, the distance along the extending direction (the distance along the left-right direction in FIG. 2) between the two ends (in FIG. 2, the left end and the right end on the surface of the tubular portion 22) on both sides in the extending direction of the second opening 421 is the length d of the second opening 421.

[0046] As described above, the diameter R of the shaft 2 is, for example, 2.45 mm, and the length d of the second opening 421 is preferably formed larger than that. For example, the length d of the second opening 421 is preferably between 2.45 mm and 20.00 mm, and between 8.00 mm and 15.00 mm. Also, the ratio (or magnification) d / R of the length d of the second opening 421 to the diameter R of the shaft 2 may be between 1.0 and 3.3, between 1.2 and 2.9, or between 1.6 and 2.5.

[0047] In this embodiment, the second guide wire 52 can be easily inserted and removed through the second opening 421, which is longer in the extending direction than the diameter R of the tubular portion 22 of the shaft 2. As schematically shown in Figure 2, the portion of the second opening 421 through which the second guide wire 52 passes is mainly located towards the tip side of the center C (midpoint of the length d along the surface of the shaft 2 or tubular portion 22) in the extending direction of the second opening 421. Thus, the second guide wire 52 typically exits the dilator 1 from the tip side (or first half) of the second opening 421.

[0048] In this case, if there is a thin-walled component of the shaft 2 immediately on the base end side, the component is prone to wrinkling, which may hinder the smooth insertion and removal of the second guide wire 52. In this embodiment, the component of the shaft 2 on the base end side from the tip through which the second guide wire 52 passes is removed (or does not exist in the first place) in the second opening 421, forming a long second opening 421, which allows the second guide wire 52 to be inserted and removed smoothly. Furthermore, even if the second guide wire 52 gets caught on the tip side of the second opening 421, the shaft 2 is made more flexible due to the long second opening 421, so the catch can be easily resolved by applying only a small additional force to the second guide wire 52.

[0049] Figure 4 is a schematic perspective view showing the external appearance of the dilator 1 according to this embodiment. In Figure 2, the second opening 421 was shown on the lower side, but in this figure, the second opening 421 is shown on the upper side. Also, in this figure, the second guide wire 52 that can pass through the second opening 421 is not shown.

[0050] As previously described with respect to Figure 2, the second opening 421 is preferably provided on the side surface of the tubular portion 22, on the base end side of the base end 21P where the tapered shape of the hole expansion portion 21 ends. The second opening 421, which extends over a length d along the extending direction, may be formed in one step or uniformly by a 3D printer or any other molding device or molding machine, but in the example of this embodiment, as will be described later, it is formed in steps through a first step involving heating and a second step involving cutting.

[0051] Therefore, as schematically shown in Figure 4, the second opening 421 according to this embodiment has two parts with different properties or formation timing at the front end and the rear end. Here, the front end portion of the second opening 421 is constructed through a first step as described later, and is therefore referred to as the initial opening 44 below. The base end portion of the second opening 421 is configured to extend the initial opening 44 toward the base end through a second step as described later, and is therefore referred to as the extended opening 45 below. A projection 46 protruding radially outward may be formed at the connection or contact point between the initial opening 44 and the extended opening 45.

[0052] In the second opening 421 described above, it is preferable that the initial opening 44, the extension opening 45, and the projection 46 all have a diameter r smaller than the diameter R of the shaft 2 so as not to interfere with the insertion of the dilator 1 or shaft 2 into the endoscope or into the body. In particular, in the second opening 421, the diameter r is at its maximum value at the projection 46. Ｍ Because it is highly likely to become r Ｍ It is preferable to form the second opening 421 such that the value of the diameter r is <R. Ｍ Preferably, the diameter of the shaft 2 is 75% to 95%, and more preferably 80% to 90%.

[0053] In the configuration described above, the diameter r (which varies depending on the axial position) of the shaft 2 or tubular portion 22 in the portion where the second opening 421 is provided is smaller than the diameter R of the tubular portion 22 in the portion where the second opening 421 is not provided (including the transition portion 22T between the hole expansion portion 21 and the second opening 421). Also, as shown in Figure 4, when the second opening 421 is provided in the tubular portion 22 on the base end side of the hole expansion portion 21, the diameter r of the tubular portion 22 in the portion where the second opening 421 is provided is smaller than the diameter R at the base end 21P of the hole expansion portion 21. Furthermore, the diameter r of the shaft 2 or tubular portion 22 at the projection 46 of the connecting portion between the initial opening 44 and the extension opening 45 Ｍ This is smaller than the diameter R of the tubular portion 22 in the part where the second opening 421 is not provided, and the diameter R at the base end 21P of the hole expansion portion 21.

[0054] Furthermore, since the diameter of the insertion hole expanded by the hole expansion portion 21 becomes larger than the diameter r of the shaft 2 or tubular portion 22 in the portion where the second opening 421 is provided, the insertion and removal of the entire dilator 1, including the second opening 421, is improved.

[0055] As will be described later, the initial opening 44 at the tip, which forms the basis of the second opening 421, is formed through a first step involving heating, so that the corners and irregularities of its edge melt with the heat and are formed into a smooth, curved shape. In this way, at least the edge of the second opening 421 at the tip may be formed into a curved shape by the heat applied when forming the shaft 2.

[0056] Figure 5 is a schematic cross-sectional view showing the edge E of the initial opening 44, which is formed into a smooth curved surface after the first step. Note that the initial opening 44 before heating may have corners and irregularities on its edge E, and if inserted into the body as is, there is a risk of damaging tissue due to the hardness of the material of the shaft 2. In this embodiment, corners and irregularities on the edge E of the initial opening 44 are removed by smoothing processes such as heating and polishing (first step), thereby increasing safety when inserting and removing the dilator 1.

[0057] As previously mentioned with respect to Figure 2, the second guidewire 52 is expected to pass mainly through the tip side of the second opening 421 (i.e., the initial opening 44). Therefore, by making the edges E on both sides in the circumferential direction (the front side and the back side in Figure 4) smooth in a curved shape at least in that portion (the tip), the second guidewire 52 can be smoothly inserted and removed. In addition, because the edges E of the second opening 421 are smooth, the dilator 1 can be smoothly inserted and removed without damaging the tissue inside the body.

[0058] Furthermore, the edge E of the initial opening 44 may be smoothly formed into a curved shape by appropriate processing such as polishing. Also, even if the second opening 421 is formed once or uniformly by a 3D printer or any other molding device or molding machine, the edge E at least on the tip side may be smoothly formed into a curved shape by heating or processing after the formation of the second opening 421.

[0059] As will be described later, the extension opening 45 on the proximal end side of the second opening 421 is formed through a second step in which the constituent material of the shaft 2 is partially cut away from the initial opening 44 after heating (first step) toward the proximal end, so corners and irregularities may exist on its edge. However, since the second guide wire 52 mainly passes through the initial opening 44, it is considered that even if corners and irregularities remain on the edge of the extension opening 45, they will not significantly hinder insertion and removal. Furthermore, such corners and irregularities are minute, and it is considered that even if the second guide wire 52 comes into contact with them, it will not interfere with insertion and removal.

[0060] As described above, in the example of Figure 4, the initial opening 44 on the tip side of the second opening 421 is heated in the first step while already open, whereas the extension opening 45 on the base end side of the second opening 421 is heated in the first step while not yet open. For this reason, the initial opening 44 may be heated slightly more strongly than the extension opening 45. Because the initial opening 44, which is heated more strongly, may shrink more due to heat than the extension opening 45, which is heated less strongly, the diameter of the shaft 2 or tubular portion 22 at the tip of the second opening 421 where the initial opening 44 is provided may be slightly smaller than the diameter of the shaft 2 or tubular portion 22 at the base end of the second opening 421 where the extension opening 45 is provided. This may lead to improved insertability of the shaft 2 and / or insertion / removal of the second guide wire 52.

[0061] Depending on how the extension opening 45 is formed, the diameter of the shaft 2 or tubular portion 22 at the tip of the second opening 421 where the initial opening 44 is provided may be slightly larger or smaller than the diameter of the shaft 2 or tubular portion 22 at the base end of the second opening 421 where the extension opening 45 is provided, and the two diameters may also be approximately equal.

[0062] In the second opening 421, the ratio of the axial length of the initial opening 44 on the tip side to the axial length of the extension opening 45 on the base end side can be arbitrarily set as long as at least some of the effects of this embodiment described above are realized. For example, by making the initial opening 44, which has a smooth edge E, long enough to sufficiently cover the axial range through which the second guide wire 52 mainly passes, the ease of inserting and removing the second guide wire 52 can be improved. Also, by making the extension opening 45, which extends from the initial opening 44 to the base end side, long enough so that the second guide wire 52 does not get caught on the base end side, the ease of inserting and removing the second guide wire 52 can be improved. The edge of the extension opening 45 may be smoothly formed into a curved shape by appropriate processing such as polishing.

[0063] In one embodiment, as schematically shown in Figure 4, the lengths of the initial opening 44 and the extended opening 45 may be approximately equal, each accounting for about 50% of the total length of the second opening 421. In another embodiment, the initial opening 44 may occupy 30% to 70% of the total length of the second opening 421 (i.e., the extended opening 45 may occupy 70% to 30% of the total length of the second opening 421).

[0064] Figure 6 schematically shows an example of a manufacturing method for the dilator 1 illustrated in Figure 4. In this example, two pieces are connected in the extending direction by a connecting member such as a heat-shrinkable tube 9. A first piece is prepared at the tip end, with an initial opening 44 that will serve as the basis for the first opening 411 and the second opening 421 already formed. A straight tubular piece is prepared at the base end, forming the main part of the tubular portion 22. The first piece corresponds to the hole expansion portion 21 and the tip portion 22D of the tubular portion 22, and the second piece corresponds to the base end portion 22P of the tubular portion 22. As shown in the figure, with these two pieces connected in a straight line along the axial direction, a heat-shrinkable tube 9 spanning both pieces is attached to the outer circumference of each piece. When heat is then applied, the heat-shrinkable tube 9 shrinks and firmly connects the two pieces.

[0065] As mentioned above, the heat applied at this time melts and smooths the edge E (Figure 5) of the initial opening 44. Alternatively, the heat applied at this time may be used to form the tapered shape of the hole expansion portion 21.

[0066] The heat that smooths the edge E of the initial opening 44 causes the shaft 2 to thin at the base end of the initial opening 44. This is schematically illustrated by the shaded area in Figure 2. Since such a thinned portion can hinder the insertion and removal of the second guide wire 52, it is preferable to remove it with a suitable tool. Because the thinned portion has become brittle due to the heat, it is easy to remove. By removing this thinned portion, the aforementioned extension opening 45 can be easily formed.

[0067] As described above, in this embodiment, after heating for connecting the two pieces, a second opening 421 including an extended opening 45 extending from the initial opening 44 towards the base can be formed by partially removing the constituent material of the shaft 2 on the base end side of the initial opening 44. As mentioned above, when forming the extended opening 45 by cutting, a projection 46 may be formed at the contact point with the initial opening 44, but since this projection 46 is located inside the outermost part of the shaft 2 and is small in size, it does not hinder the insertion of the shaft 2.

[0068] In the above embodiment, the first piece with the initial opening 44 already formed and the second piece constituting the tubular portion 22 were fused together by heat. However, the first piece without the initial opening 44 may be fused together by heat with the second piece constituting the tubular portion 22. In this case, the heat generated for the fusion of both pieces may be used to form the initial opening 44 in the first piece.

[0069] Next, as an example of a procedure using dilator 1 having the above configuration, we will show the flow of EUS-HGS (EUS-hepaticogastrostomy). EUS-HGS is a procedure in which a fistula connecting the stomach and the intrahepatic bile duct is formed using endoscopic ultrasound, and then a stent is placed.

[0070] In Figure 7, a puncture needle 71 is being fed out from the tip of an ultrasound endoscope 7 inserted into the stomach G, which is part of the digestive tract. The puncture needle 71 creates a fistula connecting the stomach G and the intrahepatic bile duct H. Then, a first guidewire 51 with a diameter of 0.018 inches is inserted into the intrahepatic bile duct H through the puncture needle 71. Subsequently, the puncture needle 71 is withdrawn as shown in Figure 8. In this state, the first guidewire 51 fed out from the tip of the ultrasound endoscope 7 extends into the intrahepatic bile duct H through the fistula created in the stomach G.

[0071] In Figure 9, the shaft 2 of the dilator 1 is inserted into the stomach G via the ultrasound endoscope 7. The shaft 2 is inserted from the proximal end (not shown) of the existing first guidewire 51 outside the body so that the existing first guidewire 51 passes through its first lumen 41. In other words, the shaft 2 is guided by the existing first guidewire 51 (and the ultrasound endoscope 7) into the stomach G and is further led to the fistula opened in the stomach G, which is the target of dilation by the dilator 1. Then, the tapered hole dilation portion 21 provided at the tip of the dilator 1 enters the fistula, thereby dilating the fistula. In this embodiment, since at least the hole dilation portion 21 (tip portion 2D) of the shaft 2 is contrast-enhanced, the hole dilation portion 21 can be visualized or observed using X-ray imaging, etc., and the shaft can be effectively inserted into the fistula, which is the part to be dilated.

[0072] In Figure 10, the tip 2D of the shaft 2 enters the intrahepatic bile duct H through the fistula expanded by the hole dilation portion 21. In this state, the second guidewire 52 is inserted from the proximal end (not shown) of the second lumen 42 of the shaft 2. The second guidewire 52 is guided by the second lumen 42 and led into the interior of the intrahepatic bile duct H through the second opening 421 at its tip. In this embodiment, a contrast marker 6 is provided to indicate the position of the second opening 421 when contrast is being used, so the second guidewire 52 can be introduced at an appropriate position in the intrahepatic bile duct H while visually confirming or imaging the position where the second guidewire 52 emerges from the second opening 421 by X-ray imaging, etc.

[0073] Subsequently, as shown in Figure 11, the shaft 2 is removed. In this state, the first guidewire 51 and the second guidewire 52, which were sent out from the tip of the ultrasound endoscope 7, extend into the intrahepatic bile duct H through the fistula opened in the stomach G. In the following Figure 12, the stent 8 is guided through the ultrasound endoscope 7 and the two existing guidewires 51 and 52 to the target site, the fistula connecting the stomach G and the intrahepatic bile duct H.

[0074] Since the fistula is dilated by the dilator 1 (hole dilator 21), the stent 8 (not shown) in its contracted state can be smoothly inserted into the fistula. With the tip of the stent 8 inserted into the fistula in the intrahepatic bile duct H and the base in the stomach G, the stomach G and the intrahepatic bile duct H are connected by the stent 8 by expanding the stent 8 as shown in the figure. Subsequently, the two guide wires 51 and 52 and the ultrasound endoscope 7 are removed from the body, leaving only the stent 8 in place (not shown).

[0075] In Figure 12, even if one of the two guidewires 51 and 52 becomes dislodged from the stent 8, the procedure can be continued using the other guidewire, which functions as a safety wire. This avoids the need to repeat the procedure, which would involve re-puncturing the stomach. Re-puncturing the stomach can lead to an increase in the amount of gastric acid that falls from the stomach into the abdominal cavity, potentially causing complications such as peritonitis. Therefore, this embodiment, which enhances the stability of the procedure with multiple guidewires 51 and 52, minimizes the risk of complications.

[0076] Furthermore, since the dilator 1 according to this embodiment is inserted deep into the body via an ultrasound endoscope 7, the insertion amount is larger compared to, for example, a dilator for blood vessels. Moreover, because it is necessary to precisely understand the positional relationship between the dilated area, such as a fistula, and the dilator 1 through contrast imaging, the procedure is much more difficult compared to simple access to blood vessels. According to this embodiment, the shaft 2 of the dilator 1 itself is contrast-enhanced, and a contrast marker 6 indicating the position of the second opening 421 is provided, thereby increasing the stability of the procedure, which is difficult as described above.

[0077] The present disclosure has been described above based on embodiments. Various modifications are possible for each component and each combination of processes in the exemplary embodiments, and it will be obvious to those skilled in the art that such modifications are included in the scope of the present disclosure.

[0078] The configuration, operation, and function of each device and method described in the embodiments can be realized by hardware resources or software resources, or by the cooperation of hardware resources and software resources. Hardware resources include, for example, processors, ROMs, RAMs, and various integrated circuits. Software resources include, for example, operating systems and application programs.

[0079] This disclosure relates to dilators, also known as dilators, and other similar devices.

[0080] 1 Dilator, 2 Shaft, 2D Tip, 2P Proximal end, 6 Contrast marker, 7 Ultrasound endoscope, 8 Stent, 9 Heat shrink tubing, 21 Hole expansion section, 22 Tubular section, 41 First lumen, 42 Second lumen, 44 Initial opening, 45 Extension opening, 46 Projection, 51 First guidewire, 52 Second guidewire, 411 First opening, 421 Second opening.

Claims

1. An expander comprising: a shaft inserted into the body via an endoscope, having a tapered hole-expanding portion at its tip and a tubular portion at its base; a first lumen provided within the shaft and having a first opening at its tip; and a second lumen provided within the shaft and having a second opening at its tip, different from the first lumen, wherein the first opening is provided at the tip of the hole-expanding portion, the second opening is provided on the side surface of the shaft, closer to the base than the first opening, and the length of the second opening along the extending direction of the shaft is greater than the diameter of the tubular portion in the radial direction perpendicular to the extending direction.

2. The expansion device according to claim 1, wherein the diameter of the shaft in the portion where the second opening is provided is smaller than the diameter of the tubular portion in the portion where the second opening is not provided.

3. The expansion device according to claim 2, wherein the second opening is formed by a first step of forming an initial opening that serves as its basis, and a second step of forming an extension opening that extends from the initial opening toward the base end, and the diameter of the shaft in the portion where the initial opening is provided is smaller than the diameter of the shaft in the portion where the extension opening is provided.

4. The expander according to any one of claims 1 to 3, wherein the edges of the second opening on both sides in the circumferential direction of the shaft are formed in a curved shape at least on the tip side of the second opening.

5. The expansion device according to claim 4, wherein a guide wire is inserted into the second lumen, and the portion of the second opening through which the guide wire passes is located toward the tip of the second opening in the extending direction.

6. The expander according to any one of claims 1 to 3, wherein a first guide wire is inserted into the first lumen, and the first guide wire is extendable from the first opening to the outside of the expander; and a second guide wire, different from the first guide wire, is inserted into the second lumen, and the second guide wire is extendable from the second opening to the outside of the expander.

7. The expansion device according to any one of claims 1 to 3, wherein the second opening is provided on the side surface of the tubular portion.

8. The expansion device according to claim 7, wherein the diameter of the tubular portion in the portion where the second opening is provided is smaller than the diameter at the base end of the hole expansion portion.

9. The hole expansion device according to any one of claims 1 to 3, wherein the tip of the hole expansion portion is provided on the central axis of the shaft.

10. The dilator according to any one of claims 1 to 3, wherein the endoscope is inserted into the digestive tract.

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