WO2025249402A1 - Dilator, and introducer assembly - Google Patents

Abstract

[Problem] To provide: a dilator that can achieve high trackability of a dilator body over a guidewire and high insertability of the dilator body into a bodily lumen even when the dilator body is configured to have a large diameter; and an introducer assembly. [Solution] A distal end 351 of a second cylindrical region 350 provided to a distal end region 300A of a dilator body 210 is located closer to an inner channel 215 side of the dilator body 210 than is a virtual line A1 connecting a distal end 341 of a first cylindrical region 340 and a distal end 361 of a third cylindrical region 360.

Description

Dilator and introducer assembly

The present invention relates to a dilator and introducer assembly.

Introducers (introducer circuits) are known that are used when performing treatments, diagnoses, etc. using various medical devices such as catheters. The introducer includes a sheath introducer equipped with a tubular sheath member and a dilator equipped with a dilator body (dilator tube) that is inserted into the lumen of the sheath member (see, for example, Patent Document 1).

In procedures using an introducer, before inserting the introducer into a biological lumen, the surgeon forms a perforation connecting the biological lumen to the outside of the body, and places a guidewire through this perforation between the biological lumen and the outside of the body. The surgeon then inserts the dilator body into the sheath member, and with the introducer and dilator assembled, inserts the guidewire into the dilator body and inserts the dilator body and sheath member into the biological lumen along the guidewire. With the sheath member still inserted into the biological lumen, the surgeon removes the dilator body from the sheath member. With the dilator body removed from the sheath member, the surgeon can use the inner cavity of the sheath member as an access route connecting the biological lumen to the outside of the body, allowing them to insert various medical devices used for treatment and diagnosis into the biological lumen.

By inserting the introducer into a perforation formed in the living body while the dilator body is inserted through the sheath member as described above, the surgeon can widen the perforation while preventing the dilator body from bending the sheath member.

The dilator body is required to have the ability to follow the guidewire inserted into the biological lumen before the sheath member, and to be easy to insert so as to reduce the burden on the surgeon when operating the dilator.

On the other hand, in recent years, attempts have been made to develop introducers intended for use in relatively large blood vessels, such as the arteries of the lower limbs (see, for example, Patent Document 2).

Japanese Patent Application Publication No. 7-303703 JP 2022-27860 A

The dilator included in the introducer described in Patent Document 2 is larger than dilators intended for use in relatively thin blood vessels such as those in the upper limbs. Therefore, the dilator body included in the dilator is also configured with a large diameter to correspond to the diameter of the blood vessel into which it is to be inserted.

When the dilator body is constructed with a large diameter, the amount of material (e.g., resin) that makes up the tubular wall of the dilator body also increases. This increases the rigidity of the tip of the dilator body, leading to a decrease in the dilator body's ability to follow the guidewire. Furthermore, the increased amount of material that makes up the tubular wall at the tip of the dilator body also increases the insertion load of the dilator body.

As a result, it becomes even more difficult to achieve followability to the guidewire and ease of insertion of the dilator body when it comes to dilator bodies that are equipped with introducers intended for use in relatively large blood vessels, such as the arteries of the lower limbs.

The present invention was made in consideration of the above-mentioned problems, and aims to provide a dilator and introducer assembly that allows the dilator body to have high followability relative to the guidewire and high insertability into the biological lumen (reduced insertion resistance of the dilator body when inserted into the biological lumen), even when the dilator body is configured with a large diameter.

The present invention can be achieved by any one of the following means (1) to (5).

(1)
a dilator body having an internal cavity with a substantially constant diameter extending from the base end to the tip end;
a dilator hub connected to a proximal end of the dilator body and having an opening communicating with an inner cavity of the dilator body,
The dilator body has a distal region, a proximal region, and an intermediate region located between the distal region and the proximal region,
The tip region is
a first tapered region in which the outer diameter decreases toward the tip;
a first cylindrical region extending from a base end of the first tapered region toward a base end side of the tip region;
a second cylindrical region located proximal to the first cylindrical region and having an outer diameter greater than the outer diameter of the first cylindrical region;
a third cylindrical region located proximal to the second cylindrical region and having an outer diameter greater than the outer diameter of the second cylindrical region;
a second tapered region located between the first cylindrical region and the second cylindrical region, the second tapered region having an outer diameter that decreases from a tip end of the second cylindrical region toward a base end of the first cylindrical region;
a third tapered region located between the second cylindrical region and the third cylindrical region, the third tapered region having an outer diameter that decreases from a tip end of the third cylindrical region toward a base end of the second cylindrical region,
A dilator in which the tip of the second cylindrical region is located closer to the inner cavity of the dilator body than an imaginary line connecting the tip of the first cylindrical region and the tip of the third cylindrical region.

(2)
a sum of the axial length of the second tapered region and the axial length of the third tapered region is equal to or greater than the axial length of the second cylindrical region;
The dilator described in (1), wherein the sum of the axial length of the first tapered region and the axial length of the second tapered region is equal to or greater than the axial length of the first cylindrical region.

(3)
The dilator according to (1) or (2), wherein the value of the outer diameter of the first cylindrical region/the outer diameter of the second cylindrical region is equal to or less than the value of the outer diameter of the second cylindrical region/the outer diameter of the third cylindrical region.

(4)
a taper angle of the third tapered region is equal to or greater than a taper angle of the second tapered region;
The dilator according to any one of (1) to (3), wherein the taper angle of the second tapered region is equal to or greater than the taper angle of the first tapered region.

(5)
A dilator according to any one of (1) to (4),
a sheath introducer including a tubular sheath member through which the dilator body can be inserted, and a sheath hub connected to a proximal end of the sheath member and connectable to the dilator hub;
the distal end region is configured as a region that protrudes distally beyond the distal end of the sheath member when the dilator body is inserted through the lumen of the sheath member,
an axial length of the third cylindrical region that is less than or equal to an axial length of the second cylindrical region and less than or equal to an axial length of the first cylindrical region;

The distal region of the dilator body of the dilator of the present invention is provided with a first tapered region, a first cylindrical region, a second tapered region, a second cylindrical region, a third tapered region, and a third cylindrical region, arranged in this order from the distal end to the proximal end. The distal region of the dilator body has an outer diameter that gradually increases from the distal end to the proximal end due to each tapered region arranged in the distal region. Therefore, when the distal region of the dilator body is inserted into a biological lumen, the dilator can gradually widen a perforation formed in the living body from the distal end to the proximal end of the distal region. This prevents a perforation formed in the living body from being suddenly widened when the dilator body is inserted into a biological lumen. This allows surgeons to reduce the burden on the patient during procedures using the dilator. The distal region of the dilator body is also provided with cylindrical regions arranged between the tapered regions. Each cylindrical region extends with a substantially constant outer diameter along the axial direction of the dilator body. Therefore, when a surgeon inserts the dilator body into a biological lumen, the insertion resistance of the dilator body can be reduced at each cylindrical region located between the tapered regions. This allows the surgeon to smoothly insert the dilator body into a biological lumen. Furthermore, the distal end of the second cylindrical region of the dilator body is located closer to the lumen of the dilator body than the imaginary line connecting the distal end of the first cylindrical region and the distal end of the third cylindrical region. This reduces the change in rigidity of the dilator body at the boundary between the distal end of the second cylindrical region and the proximal end of the second tapered region, improving flexibility near the boundary between the distal end of the second cylindrical region and the proximal end of the second tapered region. Furthermore, due to the change in rigidity at the boundary between the proximal end of the first cylindrical region and the distal end of the second tapered region, and at the boundary between the proximal end of the second cylindrical region and the distal end of the third tapered region, each boundary becomes an inflection point when the distal region is bent, improving the flexibility of the distal region. Furthermore, compared to when the shape (outer diameter) of a portion of the tip region (outer diameter changing region) from the tip of the first cylindrical region to the tip of the third cylindrical region is configured so that it follows the imaginary line or is located outward of the imaginary line when viewed from the lumen side of the dilator body, the amount of material (e.g., resin) making up the portion of the dilator body's tubular wall in the outer diameter changing region is reduced. This allows the dilator body to improve the guidewire followability of the tip region located near the most distal end of the dilator body and reduce the insertion load of the tip region. Therefore, even when the dilator body is configured with a large diameter, the dilator according to the present invention can achieve high guidewire followability and high insertability of the dilator body into a biological lumen.

FIG. 1 illustrates an introducer circuit according to an embodiment. FIG. 1 is a perspective view of a tip region of a dilator body according to an embodiment. FIG. 2 is a plan view of the tip region of the dilator body according to the embodiment. FIG. 2 is a cross-sectional view along the axial direction of the tip region of the dilator body according to the embodiment. FIG. 2 is an enlarged view showing a cross section of a portion of the tip region of the dilator body according to the embodiment. FIG. 2 is an enlarged view showing a cross section of a portion of the tip region of the dilator body according to the embodiment.

The dilator 200 according to the embodiment will be described with reference to Figures 1 to 6.

<Introductory Circuit 10>
In this embodiment, an introducer circuit (introducer) 10 including a dilator 200 will be described.

As shown in FIG. 1, the introducer circuit 10 includes a sheath introducer 100 and a dilator 200.

The surgeon can detachably fix the dilator hub 220 to the cap member 140 with the dilator body 210 inserted into the interior of the sheath hub 130 of the sheath member 110 and through the lumen 115 of the sheath member 110. In this specification, the "introducer assembly" refers to the introducer circuit 10 in the state in which the dilator body 210 of the dilator 200 is inserted into the sheath member 110 of the sheath introducer 100 to form the distal end region 300A at the distal end of the sheath member 110 (the state shown in Figures 3 to 6), or in the state before the dilator 300 and sheath introducer 100 are assembled (separated state) as shown in Figure 1.

<Sheath Introducer 100>
The sheath introducer 100 includes a tubular sheath member (sheath tube) 110 and a sheath hub 130 connected to a proximal end portion 113 of the sheath member 110 .

In the description of this specification, the direction in which the sheath member 110 extends is referred to as the "axial direction" and is indicated by arrows X1-X2. The direction indicated by arrow X1 is defined as the distal end of the axial direction, and the direction indicated by arrow X2 is defined as the proximal end of the axial direction. The axial direction of the dilator 200 (extension direction of the central axis c1) is the direction indicated by arrows X1-X2, just like the axial direction of the sheath member 110. Note that arrows Y1-Y2 in the figures indicate a direction perpendicular to the axial direction.

The sheath introducer 100 can be used to introduce various medical devices into a biological lumen (e.g., a blood vessel) via the inner lumen 115 of the sheath member 110. Specific methods and procedures for using the sheath introducer 100 are not particularly limited, but for example, it can be used to form an access path for delivering various medical devices (e.g., a stent for placement in the aorta, a device used in artificial valve replacement surgery to treat aortic stenosis, a device for treating pulmonary thrombosis, etc.) from a relatively large-diameter blood vessel running through the lower limb to various parts of the body.

The introducer circuit 10 can be used, for example, in the following procedure.

The surgeon connects the dilator 200 to the sheath introducer 100 to form an introducer assembly, and then inserts the sheath member 110 into a perforation formed in the living body that connects the outside of the living body with the biological lumen into which the sheath member 110 will be inserted, and pushes open the perforation. The dilator 200 prevents the sheath member 110 from breaking or otherwise being broken when the sheath member 110 is inserted into the biological lumen through the perforation as described above.

Prior to inserting the dilator 200 and the sheath member 110 into the biological lumen as described above, the surgeon passes a guide wire, which is positioned between the biological lumen and the outside of the living body, through the dilator body 210 via a perforation formed in the living body, and inserts the dilator 200 and sheath member 110 along the guide wire into the biological lumen. After inserting the tip 211 of the dilator body 210 to a predetermined position in the biological lumen, the surgeon removes the dilator body 210 from the sheath member 110. The surgeon can use the lumen 115 of the sheath member 110, from which the dilator body 210 has been removed, as an access route to deliver various medical devices to desired positions in the biological lumen.

As shown in Figures 1 and 2, the sheath member 110 has a distal end portion 111 with a distal end opening 111a formed at the most distal end, and a proximal end portion 113 disposed inside the sheath hub 130.

The sheath member 110 has an inner cavity 115 that extends continuously between the distal end 111 and the proximal end 113.

The proximal end 113 of the sheath member 110 is provided with a proximal end opening 113a that is positioned so as to communicate with the interior of the sheath hub 130.

As shown in Figures 1 and 3, the distal end portion 111 of the sheath member 110 has a tapered shape in which the outer diameter tapers toward the distal end.

The sheath member 110 can be made of polymeric materials such as polyolefin (e.g., polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more thereof), polyolefin elastomer, cross-linked polyolefin, polyvinyl chloride, polyamide, polyamide elastomer, polyester, polyester elastomer, polyurethane, polyurethane elastomer, fluororesin (e.g., polytetrafluoroethylene, tetrafluoroethylene-ethylene copolymer), polycarbonate, polystyrene, polyacetal, polyimide, polyetherimide, polyether ether ketone, or mixtures thereof. The sheath member 110 may also have a reinforcing member such as a metal wire within the wall thickness of a tubular member made of a polymeric material or a mixture thereof.

As shown in FIG. 1, a valve body 160 is disposed inside the sheath hub 130. The valve body 160 is configured to allow the insertion of the dilator body 210 or a medical device to be inserted into a biological lumen.

The valve body 160 prevents a gap from forming between the dilator body 210 or a medical device when the dilator body 210 or a medical device is inserted into the valve body 160. By preventing the formation of this gap, the valve body 160 prevents liquids such as blood or saline injected into the sheath hub 130 from flowing back toward the base end of the cap member 140 connected to the sheath hub 130.

The sheath hub 130 has a first port portion 171 and a second port portion 172 that communicate with the interior of the sheath hub 130.

A tube 181 can be connected to the first port portion 171, which is connected to a three-way stopcock 190 for supplying a liquid such as saline solution into the inside of the sheath hub 130.

A suction device can be connected to the second port portion 172 via a tube 182. The suction device can be used when performing procedures to aspirate blood clots, etc., from within a vein. Note that the installation of the second port portion 172 can be omitted as appropriate depending on the intended use of the introducer circuit 10, etc.

The sheath introducer 100 has a cap member 140 connected to the proximal end of the sheath hub 130. The cap member 140 has an opening (not shown) that communicates with the interior of the sheath hub 130. The surgeon can insert the dilator body 210 into the interior of the sheath hub 130 and the lumen 115 of the sheath member 110 by pushing the dilator body 210 into the proximal end of the cap member 140.

<Dilator 200>
As shown in Figures 1 to 4, the dilator 200 comprises a dilator body 210 having an inner cavity 215 that penetrates from the base end side to the tip end side with a substantially constant diameter d1, and a dilator hub 220 that is connected to the base end 213 of the dilator body 210 and has an opening 227 that communicates with the inner cavity 215 of the dilator body 210.

The dilator body 210 can be made of, for example, resin materials such as high-density polyethylene, low-density polyethylene, vinyl chloride, polyurethane, polyamide, polyester, etc.; elastomer materials such as polyurethane elastomer, polyamide elastomer, polyester elastomer, etc.; or a combination of two or more of these materials (such as a polymer blend). Furthermore, the dilator 200 may have a low-friction resin such as PTFE (polytetrafluoroethylene) disposed on the inner surface that forms the lumen 215 of the dilator body 210 made of the above materials.

As shown in FIG. 1, the proximal end 213 of the dilator body 210 is disposed in the internal space 225 of the dilator hub 220. The proximal end opening 213a formed in the proximal end 213 of the dilator body 210 is in communication with the opening 227 of the dilator hub 220 via the internal space 225 of the dilator hub 220.

As shown in FIG. 1, the dilator body 210 has a distal region 300A, a proximal region 300B, and an intermediate region 300C located between the distal region 300A and the proximal region 300B.

In this specification, when the introducer assembly is constructed (when the dilator body 210 of the dilator 200 is inserted into the sheath member 110 of the sheath introducer 100), the distal region of the dilator body 210 that protrudes distally beyond the distal end 111 of the sheath member 110 is defined as the "distal region 300A" (see Figures 3 and 4). Furthermore, the region of the dilator body 210 that is disposed within the dilator hub 220 is defined as the "proximal region 300B." Furthermore, the region extending between the distal region 300A and the proximal region 300B is defined as the "intermediate region 300C." The distal end region 300A is the distal end region of the dilator body 210 that protrudes distally beyond the distal end portion 111 of the sheath member 110 when the dilator body 210 of the dilator 200 is inserted through the sheath member 110 of the sheath introducer 100 and the dilator hub 220 is fixed to or in contact with the cap member 140.

The base end region 300B and the intermediate region 300C have approximately the same outer diameter. Furthermore, the intermediate region 300C extends from the base end 363 of the third cylindrical region 360 located in the tip end region 300A toward the base end side (see Figures 3 and 4). Therefore, in this embodiment, the outer diameters of the base end region 300B, the intermediate region 300C, and the outer diameter D3 of the third cylindrical region 360 are approximately the same.

Furthermore, as mentioned above, the inner diameter d1 (diameter of the lumen 215) of the dilator body 210 is substantially constant along the axial direction. Therefore, in this embodiment, the thickness of the base end region 300B, the thickness of the intermediate region 300C, and the thickness t3 (see Figure 5) of the third cylindrical region 360 located in the tip end region 300A are substantially constant.

As shown in Figures 2 to 6, the tip region 300A comprises a first tapered region 310 whose outer diameter decreases toward the tip of the dilator body 210, a first cylindrical region 340 extending from the base end 313 of the first tapered region 310 toward the base end of the tip region 300A, a second cylindrical region 350 located closer to the base end than the first cylindrical region 340 and having an outer diameter D2 larger than the outer diameter D1 of the first cylindrical region 340, and a second cylindrical region 350 located closer to the base end than the second cylindrical region 350 and having an outer diameter D3 of the second cylindrical region 350. It has a third cylindrical region 360 with an outer diameter D3 larger than the outer diameter D2, a second tapered region 320 located between the first cylindrical region 340 and the second cylindrical region 350, and whose outer diameter decreases from the tip 351 of the second cylindrical region 350 toward the base end 343 of the first cylindrical region 340, and a third tapered region 330 located between the second cylindrical region 350 and the third cylindrical region 360, and whose outer diameter decreases from the tip 361 of the third cylindrical region 360 toward the base end 353 of the second cylindrical region 350.

The tapered regions 310, 320, 330 and cylindrical regions 340, 350, 360 located in the tip region 300A have circular inner and outer circumferential surfaces in an orthogonal cross section (a cross section perpendicular to the central axis c1).

Each cylindrical region 340, 350, 360 extends with a substantially constant outer diameter along the axial direction of the dilator body 210. Therefore, the outer peripheral surface of each cylindrical region 340, 350, 360 extends in a substantially linear shape parallel to the central axis c1 in the drawings shown in Figures 3 and 4.

As shown in Figures 3 and 4, the tip of the dilator body 210 is located at the tip 301 of the tip region 300A. Furthermore, the tip 311 of the first tapered region 310, which is located most distally in the tip region 300A, is located at the same position as the tip 301 of the tip region 300A.

As shown in Figures 3 and 4, the base end 303 of the tip region 300A is located at the base end 363 of the third cylindrical region 360, which is located at the base end side of the tip region 300A. As mentioned above, the intermediate region 300C, which extends continuously from the third cylindrical region 360, is located on the base end side of the third cylindrical region 360. Therefore, the base end 303 of the tip region 300A is located at the boundary between the third cylindrical region 360 and the intermediate region 300C (the boundary between the tip region 300A and the intermediate region 300C).

As shown in Figures 3 and 4, the base end 313 of the first tapered region 310 is located at a position that overlaps with the tip 341 of the first cylindrical region 340, which is connected to the first tapered region 310 on the base end side of the first tapered region 310. Therefore, the base end 313 of the first tapered region 310 and the tip 341 of the first cylindrical region 340 are located at the boundary between the respective regions 310, 340.

As shown in Figures 3 and 4, the base end 343 of the first cylindrical region 340 is located at a position that overlaps with the tip 321 of the second tapered region 320 that is connected to the first cylindrical region 340 on the base end side of the first cylindrical region 340. Therefore, the base end 343 of the first cylindrical region 340 and the tip 321 of the second tapered region 320 are located at the boundary between the respective regions 340, 320.

As shown in Figures 3 and 4, the base end 323 of the second tapered region 320 is located at a position overlapping the tip 351 of the second cylindrical region 350 that is connected to the second tapered region 320 on the base end side of the second tapered region 320. Therefore, the base end 323 of the second tapered region 320 and the tip 351 of the second cylindrical region 350 are located at the boundary between the respective regions 320, 350.

As shown in Figures 3 and 4, the base end 353 of the second cylindrical region 350 is located at a position that overlaps with the tip 331 of the third tapered region 330, which is connected to the second cylindrical region 350 on the base end side of the second cylindrical region 350. Therefore, the base end 353 of the second cylindrical region 350 and the tip 331 of the third tapered region 330 are located at the boundary between each region 350, 330.

As shown in Figures 3 and 4, the base end 333 of the third tapered region 330 is located at a position overlapping the tip 361 of the third cylindrical region 360, which is connected to the third tapered region 330 on the base end side of the third tapered region 330. Therefore, the base end 333 of the third tapered region 330 and the tip 361 of the third cylindrical region 360 are located at the boundary between the respective regions 330, 360.

3 and 4, the outer diameter D1 of the first cylindrical region 340 is smaller than the outer diameter D2 of the second cylindrical region 350, which in turn is smaller than the outer diameter D3 of the third cylindrical region 360. Furthermore, as mentioned above, the diameter d1 of the lumen 215 of the dilator body 210 is substantially constant along the axial direction. Therefore, the thickness t1 of the first cylindrical region 340 is smaller than the thickness t2 of the second cylindrical region 350, which in turn is smaller than the thickness t3 of the third cylindrical region 360. Therefore, the amount of material (e.g., resin) constituting the tube wall of the distal portion of the dilator body 210 is less than that of the proximal portion of the distal region 300A. As a result, the flexibility of the distal portion of the dilator body 210 is greater in the distal portion of the distal region 300A than in the proximal portion of the distal region 300A.

The dilator body 210 has three tapered regions 310, 320, and 330 located at different axial positions in the tip region 300A. Therefore, when the tip region 300A of the dilator body 210 is inserted into a biological lumen, the dilator 200 can gradually widen a perforation formed in the living body from the distal end toward the proximal end of the tip region 300A. Therefore, when the dilator body 210 is inserted into a biological lumen, the dilator 200 can prevent a perforation formed in the living body from being suddenly widened.

The dilator body 210 also has multiple cylindrical regions 340, 350, and 360 located between each of the tapered regions 310, 320, and 330. Each of the cylindrical regions 340, 350, and 360 extends with a substantially constant outer diameter along the axial direction of the dilator body 210. Therefore, when an operator inserts the dilator body 210 into a biological lumen, the insertion resistance of the dilator body 210 can be reduced in each of the cylindrical regions 340, 350, and 360 located between each of the tapered regions 310, 320, and 330.

As shown in Figures 3, 4, and 6, the tip 351 of the second cylindrical region 350 is located closer to the lumen 215 of the dilator body 210 (closer to the central axis c1) than the imaginary line A1 connecting the tip 341 of the first cylindrical region 340 and the tip 361 of the third cylindrical region 360.

The imaginary line A1 can be defined as an imaginary straight line connecting the tip 341 of the first cylindrical region 340 and the tip 361 of the third cylindrical region 360 on the plan view shown in Figure 3 (or the axial cross-sectional view shown in Figure 4) in a natural state where no external force is applied to the dilator body 210.

In this embodiment, the axial range of the tip region 300A located between the tip 341 of the first cylindrical region 340, which serves as the reference for drawing the virtual line A1, and the tip 361 of the third cylindrical region 360, is defined as the "outer diameter change region 370."

As described above, the tip 351 of the second cylindrical region 350 of the dilator body 210 is located closer to the lumen 215 of the dilator body 210 than the imaginary line A1 connecting the tip 341 of the first cylindrical region 340 and the tip 361 of the third cylindrical region 360. Therefore, the change in rigidity of the dilator body 210 at the boundary between the tip 351 of the second cylindrical region 350 and the base end 323 of the second tapered region 320 is alleviated, and flexibility is improved near the boundary between the tip 351 of the second cylindrical region 350 and the base end 323 of the second tapered region 320. Therefore, the flexibility of the dilator body 210 changes smoothly from the base end to the tip end of a portion of the tip region 300A (outer diameter changing region 370) from the tip 341 of the first cylindrical region 340 to the tip 361 of the third cylindrical region 360. Furthermore, due to changes in rigidity at the boundary between the base end 343 of the first cylindrical region 340 and the tip 321 of the second tapered region 320, and at the boundary between the base end 353 of the second cylindrical region 350 and the tip 331 of the third tapered region 330, each boundary becomes an inflection point when the tip region 300A is bent, improving the flexibility of the tip region 300A. Furthermore, compared to when the dilator body 210 is configured so that the shape (outer diameter) of a portion of the tip region 300A (outer diameter changing region 370) from the tip 341 of the first cylindrical region 340 to the tip 361 of the third cylindrical region 360 is along the imaginary line A1 or is located outside the imaginary line A1 when viewed from the lumen 215 side of the dilator body 210, the amount of constituent material (e.g., resin amount) of the portion forming the tubular wall of the dilator body 210 in the outer diameter changing region 370 is reduced. As a result, the dilator body 210 can improve the guidewire followability of the tip region 300A located near the most distal end of the dilator body 210 and reduce the insertion load of the tip region 300A (improving insertability into a biological lumen).

In the above explanation, "when the shape (outer diameter) of the outer diameter changing region 370 changes so as to follow the imaginary line A1 or to be positioned outside the lumen 215 of the dilator body 210 relative to the imaginary line A1" means that the constituent material of the portion forming the tubular wall of the dilator body 210 is present in the gap between the imaginary line A1 shown in Figure 3 and the outer peripheral surface of each part included in the outer diameter changing region 370, or that the constituent material of the portion forming the tubular wall of the dilator body 210 is present beyond the imaginary line A1 on the far side as viewed from the lumen 215.

Next, we will explain the preferred size relationships between the dimensions of each part of the dilator body 210.

The sum of the axial length L12 of the second tapered region 320 and the axial length L13 of the third tapered region 330 shown in FIG. 3 can be formed to be equal to or greater than the axial length L22 of the second cylindrical region 350. Furthermore, the sum of the axial length L11 of the first tapered region 310 and the axial length L12 of the second tapered region 320 can be formed to be equal to or greater than the axial length L21 of the first cylindrical region 340.

As described above, the dilator body 210 is formed so that the sum of the axial length L12 of the second tapered region 320 and the axial length L13 of the third tapered region 330 is greater than the axial length L22 of the second cylindrical region 350 extending between each tapered region 320, 330.This reduces insertion resistance using the second cylindrical region 350 located between each tapered region 320, 330, while allowing for gradual changes in the outer diameter of the dilator body 210 at the tip and base ends of the second cylindrical region 350. Similarly, the dilator body 210 is formed so that the sum of the axial length L11 of the first tapered region 310 and the axial length L12 of the second tapered region 320 is equal to or greater than the axial length L21 of the first cylindrical region 340 located between the tapered regions 310, 320. This reduces insertion resistance using the first cylindrical region 340 located between the tapered regions 310, 320, while allowing for gentle changes in the outer diameter of the dilator body 210 on the distal and proximal sides of the first cylindrical region 340.

Incidentally, when configuring the outer diameter change of each tapered region 310, 320, 330 as gradually as possible as described above, it is preferable to make the axial lengths L11, L12, L13 of each tapered region 310, 320, 330 as long as possible. However, if the axial lengths L11, L12, L13 of each tapered region 310, 320, 330 were simply increased, the ratio of the axial lengths L21, L22 of each cylindrical region 340, 350 to the axial length of each tapered region 310, 320, 330 would become relatively small, making it difficult to suppress insertion resistance. In this embodiment, by adjusting the axial lengths of each region as described above in the tip region 300A having a predetermined axial length La, the outer diameter change of each tapered region 310, 320, 330 is made gradually while reducing the insertion resistance of each cylindrical region 340, 350.

The value of the outer diameter D1 of the first cylindrical region 340/the outer diameter D2 of the second cylindrical region 350 (D1/D2) shown in Figure 3 can be formed to be equal to or less than the value of the outer diameter D2 of the second cylindrical region 350/the outer diameter D3 of the third cylindrical region 360 (D2/D3).

As described above, the dilator body 210 is formed so that the value of (D1/D2) is equal to or less than the value of (D2/D3), so that the rate of change in outer diameter between the first cylindrical region 340 and the second cylindrical region 350 is greater than the rate of change in outer diameter between the second cylindrical region 350 and the third cylindrical region 360. In other words, when comparing the amount of change in outer diameter between each of the cylindrical regions 340, 350, and 360 in the distal region 300A, the rate of reduction in the outer diameter of each of the cylindrical regions 340, 350, and 360 increases from the base end to the distal end. Therefore, the dilator body 210 is formed with a greater reduction in the amount of material constituting the tube walls of each of the cylindrical regions 340, 350, and 360 from the base end to the distal end of the distal region 300A, and is more flexible toward the distal end of the distal region 300A.

The taper angle θ3 (see FIG. 5) of the third tapered region 330 can be greater than or equal to the taper angle θ2 (see FIG. 6) of the second tapered region 320. Furthermore, the taper angle θ2 of the second tapered region 320 can be greater than or equal to the taper angle θ1 (see FIG. 6) of the first tapered region 310.

Each taper angle θ1, θ2, and θ3 can be defined as the angle between an imaginary line H1 parallel to the central axis c1 and the outer circumferential surface of each tapered region 310, 320, and 330 in a cross section along the axial direction of the dilator body 210.

As described above, the dilator body 210 is configured so that the taper angles θ1, θ2, θ3 of each tapered region 310, 320, 330 become smaller from the base end to the tip end. As a result, the first tapered region 310 located on the tip side of the tip region 300A experiences a steeper change in outer diameter due to the taper than the other tapered regions 320, 330 located on the base end side. As a result, the dilator body 210 can further effectively improve the insertability of the first tapered region 310 located at the tip end, which is thinner and more flexible.

As shown in Figures 3 and 4, when the introducer assembly is configured, the axial length L23 of the third cylindrical region 360 is less than or equal to the axial length L22 of the second cylindrical region 350, and is less than or equal to the axial length L21 of the first cylindrical region 340.

As described above, the introducer assembly is configured so that the axial length L23 of the third cylindrical region 360 has a predetermined length. Therefore, when the dilator body 210 is inserted into the lumen 115 of the sheath member 110, a cylindrical region (straight portion) of a predetermined length can be positioned between the tip of the sheath member 110 (the position of the tip opening 111a) and the base end 333 of the third tapered region 330, which is the tapered region located most proximal in the tip region 300A. This prevents the formation of a point (a step) where the outer diameter changes suddenly between the tip of the sheath member 110 and the base end 333 of the third tapered region 330. Therefore, the introducer assembly enables the dilator body 210 to be smoothly inserted into a biological lumen.

Furthermore, when the introducer assembly is configured so that the axial length L23 of the third cylindrical region 360 is equivalent to the axial length L22 of the second cylindrical region 350 and the axial length L11 of the first cylindrical region 340, the axial length L23 of the third cylindrical region 360 can be prevented from becoming excessively large. This prevents the introducer assembly from bending the third cylindrical region 360 when inserting the dilator body 210 into a biological lumen, making it possible to smoothly insert the dilator body 210 into a biological lumen with less pushing force.

In order to prevent the formation of a point (step) where the outer diameter changes suddenly as described above, and to prevent the third cylindrical region 360 from bending as described above when the dilator body 210 is inserted into a biological lumen, the introducer assembly preferably has an axial length L23 of the third cylindrical region 360 that is less than half the outer diameter D3 of the third cylindrical region 360, and more preferably is 3 mm or greater.

The introducer circuit 10 can adopt the following example dimensions as an example for achieving the dimensional relationships of the various parts described above.

The axial length of the sheath member 110 can be, for example, 300 mm or more and 1000 mm or less.

The diameter (inner diameter) of the lumen 115 of the sheath member 110 can be formed, for example, to be equal to or greater than 5.0 mm and equal to or less than 10.0 mm. The diameter of the distal end opening 111a of the sheath member 110 and the diameter of the proximal end opening 113a of the sheath member 110 can be formed to be approximately the same as the diameter of the lumen 115 of the sheath member 110.

The axial length La (see Figure 3) of the tip region 300A of the dilator body 210 can be formed to be, for example, 50 mm or more and 100 mm or less.

The axial length of the proximal region 300B of the dilator body 210 can be formed to be, for example, 5.0 mm or more and 15.0 mm or less.

The axial length of the intermediate region 300C of the dilator body 210 can be formed to be, for example, 300 mm or more and 1000 mm or less.

The diameter d1 (inner diameter shown in Figure 4) of the lumen 215 of the dilator body 210 can be formed to be, for example, 0.9 mm or more and 2.0 mm or less. The diameter of the distal opening 211a of the dilator body 210 and the diameter of the proximal opening 213a of the dilator body 210 can be formed to be approximately the same as the diameter d1 of the lumen 215 of the dilator body 210.

The axial length L11 (see Figure 3) of the first tapered region 310 can be formed to be, for example, 5 mm or more and 15 mm or less.

The axial length L12 (see Figure 3) of the second tapered region 320 can be formed to be, for example, 5 mm or more and 15 mm or less.

The axial length L13 (see Figure 3) of the third tapered region 330 can be formed to be, for example, 5 mm or more and 15 mm or less.

The taper angle θ1 (see Figure 6) of the first tapered region 310 can be formed to be, for example, 1.3° or more and 4.0° or less.

The taper angle θ2 (see Figure 6) of the second tapered region 320 can be formed to be, for example, not less than 3.6° and not more than 10.7°.

The taper angle θ3 (see Figure 5) of the third tapered region 330 can be formed to be, for example, 4.6° or more and 13.5° or less.

The axial length L21 (see Figure 3) of the first cylindrical region 340 can be formed to be, for example, 10 mm or more and 30 mm or less.

The axial length L22 (see Figure 3) of the second cylindrical region 350 can be formed to be, for example, 10 mm or more and 30 mm or less.

The axial length L23 (see Figure 3) of the third cylindrical region 360 can be formed to be, for example, 10 mm or more and 30 mm or less.

The outer diameter D1 (see Figure 3) of the first cylindrical region 340 can be formed to be, for example, 2.2 mm or more and 3.0 mm or less. The wall thickness t1 (see Figure 6) of the first cylindrical region 340 can be formed to be, for example, 0.1 mm or more and 1.1 mm or less.

The outer diameter D2 (see Figure 3) of the second cylindrical region 350 can be formed to be, for example, 3.0 mm or more and 5.0 mm or less. The wall thickness t2 (see Figure 5) of the second cylindrical region 350 can be formed to be, for example, 0.5 mm or more and 2.1 mm or less.

The outer diameter D3 (Figure 3) of the third cylindrical region 360 can be formed to be, for example, 5.0 mm or more and 10.0 mm or less. The wall thickness t3 (see Figure 5) of the third cylindrical region 360 can be formed to be, for example, 1.5 mm or more and 4.6 mm or less.

As described above, the dilator 200 according to this embodiment comprises a dilator body 210 having an inner cavity 115 penetrating from the base end side to the tip end side with a substantially constant diameter d1, and a dilator hub 220 connected to the base end 113 of the dilator body 210 and having an opening 227 communicating with the inner cavity 215 of the dilator body 210. The dilator body 210 has a tip region 300A, a base region 300B, and an intermediate region 300C located between the tip region 300A and the base region 300B. The tip region 300A has a first tapered region 310 whose outer diameter decreases toward the tip end of the dilator body 210, and a second tapered region 310 extending from the base end 313 of the first tapered region 310 toward the base end side of the tip region 300A. a first cylindrical region 340 extending from the distal end 351 of the second cylindrical region 350 toward the proximal end; a second cylindrical region 350 located closer to the proximal end than the first cylindrical region 340 and having an outer diameter D2 larger than the outer diameter D1 of the first cylindrical region 340; a third cylindrical region 360 located closer to the proximal end than the second cylindrical region 350 and having an outer diameter D3 larger than the outer diameter D2 of the second cylindrical region 350; a second tapered region 320 located between the first cylindrical region 340 and the second cylindrical region 350 and having an outer diameter that decreases from the distal end 351 of the second cylindrical region 350 toward the proximal end 343 of the first cylindrical region 340; and a third tapered region 330 located between the second cylindrical region 350 and the third cylindrical region 360 and having an outer diameter that decreases from the distal end 361 of the third cylindrical region 360 toward the proximal end 353 of the second cylindrical region 350.

As described above, the distal region 300A of the dilator body 210 included in the dilator 200 is arranged, in this order from the distal end to the proximal end, with the first tapered region 310, first cylindrical region 340, second tapered region 320, second cylindrical region 350, third tapered region 330, and third cylindrical region 360. The distal region 300A of the dilator body 210 has an outer diameter that gradually increases from the distal end to the proximal end due to the tapered regions 310, 320, and 330 arranged in the distal region 300A. Therefore, when inserting the distal region 300A of the dilator body 210 into a biological lumen, the dilator 200 can gradually widen a perforation formed in the living body from the distal end toward the proximal end of the distal region 300A. This allows the dilator 200 to prevent a perforation formed in the living body from being suddenly widened when the dilator body 210 is inserted into a biological lumen. As a result, surgeons can reduce the burden on patients during procedures using the dilator 200.

Furthermore, the tip region 300A of the dilator body 210 is provided with cylindrical regions 340, 350, and 360 arranged between the tapered regions 310, 320, and 330. Each of the cylindrical regions 340, 350, and 360 extends with a substantially constant outer diameter along the axial direction of the dilator body 210. Therefore, when an operator inserts the dilator body 210 into a biological lumen, the insertion resistance of the dilator body 210 can be reduced in each of the cylindrical regions 340, 350, and 360 arranged between the tapered regions 310, 320, and 330. This allows the operator to smoothly insert the dilator body 210 into the biological lumen while reducing the burden on the patient, such as pain, that occurs when the dilator body 210 pushes open the perforation.

Furthermore, the tip 351 of the second cylindrical region 350 of the dilator body 210 is located closer to the lumen 215 of the dilator body 210 than the imaginary line A1 connecting the tip 341 of the first cylindrical region 340 and the tip 361 of the third cylindrical region 360. As a result, the change in rigidity of the dilator body 210 at the boundary between the tip 351 of the second cylindrical region 350 and the base end 323 of the second tapered region 320 is alleviated, and flexibility is improved near the boundary between the tip 351 of the second cylindrical region 350 and the base end 323 of the second tapered region 320. Furthermore, due to changes in rigidity at the boundary between the base end 343 of the first cylindrical region 340 and the tip 321 of the second tapered region 320, and at the boundary between the base end 353 of the second cylindrical region 350 and the tip 331 of the third tapered region 330, each boundary becomes an inflection point when the tip region 300A is bent, improving the flexibility of the tip region 300A. Furthermore, compared to when the dilator body 210 is configured so that the shape (outer diameter) of a portion of the tip region 300A (outer diameter changing region 370) from the tip 341 of the first cylindrical region 340 to the tip 361 of the third cylindrical region 360 is along the imaginary line A1 or is located outside the imaginary line A1 when viewed from the lumen 215 side of the dilator body 210, the amount of constituent material (e.g., resin amount) of the portion forming the tubular wall of the dilator body 210 in the outer diameter changing region 370 is reduced. This allows the dilator body 210 to improve the followability of the tip region 300A, which is located near the most distal end of the dilator body 210, to the guidewire, and improves the insertability of the tip region 300A into a biological lumen.

As described above, the dilator 200 according to this embodiment can achieve high followability of the dilator body 210 relative to the guidewire and high insertability of the dilator body 210 into a biological lumen, even when the dilator body 210 is configured with a large diameter.

Furthermore, the dilator body 210 can be formed so that the sum of the axial length L12 of the second tapered region 320 and the axial length L13 of the third tapered region 330 is equal to or greater than the axial length L22 of the second cylindrical region 350, and the sum of the axial length L11 of the first tapered region 310 and the axial length L12 of the second tapered region 320 is equal to or greater than the axial length L21 of the first cylindrical region 340.

As described above, the dilator body 210 is formed so that the sum of the axial length L12 of the second tapered region 320 and the axial length L13 of the third tapered region 330 is greater than the axial length L22 of the second cylindrical region 350 extending between each tapered region 320, 330.This allows the second cylindrical region 350 located between each tapered region 320, 330 to reduce insertion resistance, while also allowing for gradual changes in the outer diameter of the dilator body 210 at the tip and base ends of the second cylindrical region 350. Furthermore, the dilator body 210 is formed so that the sum of the axial length L11 of the first tapered region 310 and the axial length L12 of the second tapered region 320 is equal to or greater than the axial length L21 of the first cylindrical region 340 extending between the tapered regions 310, 320. This reduces insertion resistance due to the first cylindrical region 340 located between the tapered regions 310, 320, while allowing for gentle changes in the outer diameter of the dilator body 210 on the distal and proximal sides of the first cylindrical region 340. Therefore, the dilator body 210 can more effectively improve the insertability of the distal region 300A into a biological lumen.

Furthermore, the dilator body 210 is formed so that the value of outer diameter D1 of the first cylindrical region 340 / outer diameter D2 of the second cylindrical region 350 (D1/D2) is equal to or less than the value of outer diameter D2 of the second cylindrical region 350 / outer diameter D3 of the third cylindrical region 360 (D2/D3).

As described above, the dilator body 210 is formed so that the value of (D1/D2) is equal to or less than the value of (D2/D3), and therefore the rate of change in outer diameter between the first cylindrical region 340 and the second cylindrical region 350 is greater than the rate of change in outer diameter between the second cylindrical region 350 and the third cylindrical region 360. Therefore, when comparing the amount of change in outer diameter between each of the cylindrical regions 340, 350, and 360 in the distal region 300A, the rate of reduction in the outer diameter of each of the cylindrical regions 340, 350, and 360 increases from the base end to the distal end. As a result, the dilator body 210 experiences a greater reduction in the amount of constituent material in the portions forming the tube walls of each of the cylindrical regions 340, 350, and 360 from the base end to the distal end of the distal region 300A. As a result, the dilator body 210 can be made more flexible near the tip 301 of the tip region 300A, which can more effectively improve the followability of the tip portion 211 of the dilator body 210 to the guidewire.

Furthermore, the dilator body 210 has a taper angle θ3 of the third taper region 330 that is greater than or equal to the taper angle θ2 of the second taper region 320, and a taper angle θ2 of the second taper region 320 that is greater than or equal to the taper angle θ1 of the first taper region 310.

As described above, the dilator body 210 is configured so that the taper angles θ1, θ2, θ3 of each tapered region 310, 320, 330 become smaller from the base end to the tip end. As a result, the first tapered region 310 located on the tip side of the tip region 300A experiences a steeper change in outer diameter due to the taper than the other tapered regions 320, 330 located on the base end side. As a result, the dilator body 210 can further effectively improve the insertability of the first tapered region 310 located at the tip end, which is configured to be thinner and more flexible.

In addition, in an introducer assembly having a dilator 200, a sheath introducer 100 including a tubular sheath member 110 through which a dilator body 210 can be inserted, and a sheath hub 130 connected to the proximal end 113 of the sheath member 110 and connectable to the dilator 200, the distal region 300A is configured as a region that protrudes distally beyond the distal end of the sheath member 110 when the dilator body 210 is inserted through the lumen 115 of the sheath member 110, and the axial length L23 of the third cylindrical region 360 is equal to or less than the axial length L22 of the second cylindrical region 350 and equal to or less than the axial length L21 of the first cylindrical region 340.

As described above, the introducer assembly is configured so that the axial length L23 of the third cylindrical region 360 has a predetermined length. Therefore, when the dilator body 210 is inserted into the lumen 115 of the sheath member 110, a cylindrical region (straight portion) of a predetermined length can be positioned between the tip of the sheath member 110 (the position of the tip opening 111a) and the proximal end 333 of the third tapered region 330, which is the tapered region located most proximal within the tip region 300A. This prevents the formation of a point (a step) where a sudden change in outer diameter occurs between the tip of the sheath member 110 and the proximal end 333 of the third tapered region 330 when the dilator body 210 is inserted into a biological lumen. Therefore, the dilator body 210 can more effectively improve the insertability of the tip region 300A into a biological lumen.

Furthermore, when the introducer assembly is configured so that the axial length L23 of the third cylindrical region 360 is equivalent to the axial length L22 of the second cylindrical region 350 and the axial length L11 of the first cylindrical region 340, the axial length L23 of the third cylindrical region 360 can be prevented from becoming excessively large. This prevents the introducer assembly from bending the third cylindrical region 360 when inserting the dilator body 210 into a biological lumen, allowing the dilator body 210 to be inserted smoothly into the biological lumen with less pushing force.

The dilator and introducer assembly according to the present invention has been described above through embodiments, but the present invention is not limited to the content described in this specification and can be modified as appropriate based on the claims.

The structure of each part and the arrangement of components described in the specification may be modified as appropriate, and additional components illustrated may be omitted or other additional components may be used as appropriate.

This application is based on Japanese Patent Application No. 2024-86075, filed on May 28, 2024, the disclosure of which is incorporated herein by reference in its entirety.

10 Introducer circuit 100 Sheath introducer 110 Sheath member 111 Distal portion of sheath member 113 Proximal end portion of sheath member 115 Lumen of sheath member 130 Sheath hub 200 Dilator 210 Dilator body 211 Distal portion of dilator body 211a Distal opening of dilator body 213 Proximal end portion of dilator body 213a Proximal opening of dilator body 215 Lumen of dilator body 220 Dilator hub 227 Opening 300A of dilator hub Distal region 300B Proximal region 300C Intermediate region 301 Distal end 303 of distal region Proximal end 310 of distal region 311 Distal end 313 of first tapered region Proximal end 320 of first tapered region 321 Distal end 323 of second tapered region Proximal end 330 of second tapered region 331 Distance 333 of third tapered region, base end 340 of third tapered region, First cylindrical region 341, Distance 343 of first cylindrical region, Base end 350 of first cylindrical region, Second cylindrical region 351, Distance 353 of second cylindrical region, Base end 360 of second cylindrical region, Third cylindrical region 361, Distance 363 of third cylindrical region, Base end 370 of third cylindrical region, Outer diameter changing region A1, Virtual line c1, Central axis La of dilator body, Axial length L11 of distal region, Axial length L12 of first tapered region, Axial length L13 of second tapered region, Axial length L21 of first cylindrical region, Axial length L22 of second cylindrical region, Axial length L23 of third cylindrical region, Axial length D1 of third cylindrical region, Outer diameter D2 of first cylindrical region, Outer diameter D3 of second cylindrical region, Outer diameter d1 of third cylindrical region, Diameter t1 of inner cavity, Wall thickness t2 of first cylindrical region, Wall thickness t3 of second cylindrical region, Wall thickness θ1 of third cylindrical region, Taper angle θ2 of first tapered region Taper angle θ3 of second tapered region Taper angle θ4 of third tapered region

Claims (5)

a dilator body having an internal cavity with a substantially constant diameter extending from the base end to the tip end;
a dilator hub connected to a proximal end of the dilator body and having an opening communicating with an inner cavity of the dilator body,
The dilator body has a distal region, a proximal region, and an intermediate region located between the distal region and the proximal region,
The tip region is
a first tapered region in which the outer diameter decreases toward the tip;
a first cylindrical region extending from a base end of the first tapered region toward a base end side of the tip region;
a second cylindrical region located proximal to the first cylindrical region and having an outer diameter greater than the outer diameter of the first cylindrical region;
a third cylindrical region located proximal to the second cylindrical region and having an outer diameter greater than the outer diameter of the second cylindrical region;
a second tapered region located between the first cylindrical region and the second cylindrical region, the second tapered region having an outer diameter that decreases from a tip end of the second cylindrical region toward a base end of the first cylindrical region;
a third tapered region located between the second cylindrical region and the third cylindrical region, the third tapered region having an outer diameter that decreases from a tip end of the third cylindrical region toward a base end of the second cylindrical region,
A dilator in which the tip of the second cylindrical region is located closer to the inner cavity of the dilator body than an imaginary line connecting the tip of the first cylindrical region and the tip of the third cylindrical region. a sum of the axial length of the second tapered region and the axial length of the third tapered region is equal to or greater than the axial length of the second cylindrical region;
The dilator according to claim 1 , wherein the sum of the axial length of the first tapered region and the axial length of the second tapered region is equal to or greater than the axial length of the first cylindrical region. The dilator described in claim 1, wherein the value of the outer diameter of the first cylindrical region/the outer diameter of the second cylindrical region is equal to or less than the value of the outer diameter of the second cylindrical region/the outer diameter of the third cylindrical region. a taper angle of the third tapered region is equal to or greater than a taper angle of the second tapered region;
The dilator according to claim 1 , wherein the taper angle of the second tapered region is equal to or greater than the taper angle of the first tapered region. The dilator according to any one of claims 1 to 4,
a sheath introducer including a tubular sheath member through which the dilator body can be inserted, and a sheath hub connected to a proximal end of the sheath member and connectable to the dilator hub;
the distal end region is configured as a region that protrudes distally beyond the distal end of the sheath member when the dilator body is inserted through the lumen of the sheath member,
an axial length of the third cylindrical region that is less than or equal to an axial length of the second cylindrical region and less than or equal to an axial length of the first cylindrical region;