JP6847617B2 - Medical systems and devices - Google Patents

Description

The present invention relates to medical systems and devices for puncturing living tissues and treatment methods.

The heart circulates blood by repeating contraction and expansion at appropriate timings by passing an electric current through the myocardial tissue called the conduction system. If the generation or transmission of electrical signals flowing through this conduction system becomes abnormal, contraction and expansion cannot be performed at appropriate timings, resulting in arrhythmia.

As a method for treating arrhythmia, a method of ablating and blocking the conduction path of a signal causing arrhythmia by heating or cooling is known. As a device for performing this therapeutic method, a device that can be percutaneously inserted into the left atrium and ablate the conduction path of a signal located at the pulmonary vein opening is known. Such ablation devices are widely used because they are minimally invasive and highly effective.

When performing ablation in the left atrium, a needle is pierced into a thin partition wall called the fossa ovalis of the atrial septum from the right atrium to make a hole leading from the right atrium to the left atrium, which is called atrial septal puncture (Blockenbrouch method). A procedure is required (see, for example, Patent Document 1). This procedure can be associated with serious complications of cardiac tamponade (a condition in which blood accumulates between the pericardium and myocardium, resulting in cardiac failure) if a false puncture is made at a site other than the target position. Therefore, during the puncture procedure, it is necessary to separately insert a catheter called an intracardiac echocardiography catheter (ICE) into the right atrium and specify the position of the foramen ovale in advance.

International Publication No. 2007/147060

The device described in Patent Document 1 is maintained in a state in which the puncture needle protrudes from the dilator after puncturing. Therefore, there is a possibility of erroneous puncture by a sharp puncture needle. In addition, the need for an intracardiac echocatheter requires labor for the technician and a heavy physical and economic burden on the patient.

The present invention has been made to solve the problems described above, the position at which the piercing can easily grasp, to provide a medical system and a medical device that erroneous piercing can increase safety by suppressing With the goal.

A medical system that achieves the above object is a medical system that is inserted into a living lumen to pierce a living tissue and hold the formed hole in a widened state, and is a first lumen penetrating in the axial direction. A dilator having a reduced diameter portion at the distal end where the outer diameter decreases toward the distal side, an outer sheath having a lumen into which the dilator can be inserted, and axial movement to the dilator. It has a positioning portion that is possible and can project distal to the dilator, and a long puncture device that can be inserted into the first lumen of the dilator, wherein the dilator has a central axis. two second rumen down is formed along the second rumen down is open at the reduced diameter portion, the positioning portion, a can protrude from said second lumen of each of said dilator It has two long support portions that are elastically deformable and a contact portion that is supported by a distal portion of the support portion, and the contact portion can be accommodated in the reduced diameter portion. a concave housing part is formed, the two second lumen that has an opening in the receiving portion in common.

A medical device that achieves the above object is a medical device that is inserted into a living lumen to widen a hole in a living tissue, and a first lumen penetrating in the axial direction is formed at a distal end. A dilator having a reduced diameter portion whose outer diameter decreases toward the distal side, and a dilator that is movably arranged in the dilator in the axial direction of the dilator and can protrude from the reduced diameter portion to the distal side of the dilator. has a Do positioning portion, said dilator is along the central axis two second rumen down formation, the second rumen down is open at the reduced diameter portion, the positioning unit, It has two long supports that are protrudable and elastically deformable from each of the second lumens of the dilator and a contact that is supported at the distal end of the support. , the reduced diameter portion, the contact portion accommodating portion capable of accommodating concave shape a is formed, the two second lumen that has an opening in the receiving portion in common.

Configured medical systems and medical devices as described above, by pushing the dilator may be a positioning portion protruding from dilator contacts the edges of the recess of the body tissue. As a result, the puncture position can be easily grasped, and the dilator can be positioned at an appropriate position appropriately separated from the edge portion of the concave portion of the living tissue. Therefore, it is possible to puncture an appropriate position, suppress erroneous puncture, and enhance safety.

It is a top view which shows the medical system which concerns on embodiment. It is sectional drawing which shows the medical system which concerns on embodiment. It is sectional drawing which shows the state which combined each device of the medical system which concerns on embodiment. It is sectional drawing which follows the AA line of FIG. It is a perspective view which shows the distal part of a medical system. It is a side view which shows the distal part of a medical system, (A) shows the containment state, (B) shows the protruding state, and (C) shows the bending state. It is a top view which shows the distal part of a medical system, (A) shows the accommodation state, (B) shows the protruding state, and (C) shows the bending state. It is a partial cross-sectional view which shows the inside of a heart. It is sectional drawing for demonstrating the procedure by the medical system which concerns on embodiment, (A) is the state which inserted the sheath assembly into the right atrium along the guide wire, (B) is the state which protruded the positioning part. (C) shows a state in which the dilator is positioned, and (D) shows a state in which the dilator is punctured by the puncture device. It is a top view for demonstrating the procedure by the medical system which concerns on embodiment, (A) is the state which the sheath assembly was inserted into the right atrium along the guide wire, (B) is the state which the positioning part protruded, (C) is a cross-sectional view showing a state in which the foramen ovale is punctured by the puncture device. It is sectional drawing for demonstrating the procedure by the medical system which concerns on embodiment, (A) is the state which the positioning part was retracted, (B) is a dilator and a sheath inserted into the hole of the foramen ovale along the puncture device. In the state (C), the dilator and the puncture device are pulled out from the outer sheath. It is sectional drawing which shows the 1st modification of a medical system. It is sectional drawing which shows the modification of the medical system, (A) shows the 2nd modification, (B) shows the 3rd modification, and (C) shows the 4th modification. It is sectional drawing which shows the modification of the medical system, (A) shows the fifth modification, (B) shows the sixth modification. It is a side view which shows the 7th modification of a medical system. It is a top view which shows the 8th modification of the medical system, (A) shows the state which the support part protruded, and (B) shows the state which the support part was bent. It is a side view which shows the 8th modification of the medical system, (A) shows the state which the support part protruded, and (B) shows the state which the support part was bent. 9 is a side view showing a ninth modification of the medical system, in which (A) shows a state in which the support portion protrudes, and (B) shows a state in which the support portion is bent. It is a perspective view which shows the tenth modification of a medical system.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. The dimensional ratios in the drawings may be exaggerated and differ from the actual ratios for convenience of explanation. In the present specification, the side of the device to be inserted into the blood vessel is referred to as the "distal side", and the hand side to be operated is referred to as the "proximal side".

In the medical system 10 according to the embodiment of the present invention, a hole is formed in the foramen ovale O of the atrial septum from the right atrium R (see FIG. 8), and a hole leading from the right atrium R to the left atrium L is widened. Used to hold. If there is a hole in the foramen ovale O, a percutaneously inserted ablation catheter into the vena cava is guided to the right atrium R and then inserted into the left atrium through the hole to ablate around the pulmonary vein opening, for example. Can be done. That is, the medical system 10 is a device for forming an access route for an ablation catheter in the foramen ovale O.

As shown in FIGS. 1 to 5, the medical system 10 according to the first embodiment includes a puncture device 60, a dilator 40, an outer sheath 50, and a positioning portion 20. The dilator 40 and the positioning unit 20 are connected to form one medical device.

The puncture device 60 is a device for forming a hole in the foramen ovale O. The puncture device 60 has a long wire rod portion 62 and a sharp puncture needle 61 provided at the distal end of the wire rod portion 62. The puncture device 60 does not have to have a sharp puncture needle 61. The puncture device may be, for example, a device that denatures and punctures a living tissue by using a high frequency current, an electromagnetic wave, a laser, cooling, or the like.

The dilator 40 is used to widen the hole in the foramen ovale O opened by the puncture device 60. The dilator 40 has a dilator central portion 41 having a substantially constant outer diameter, a tapered portion 42 (reduced diameter portion) located on the distal side of the dilator central portion 41, and a dilator near the dilator located on the proximal side of the dilator central portion 41. It has a position 43. The dilator central portion 41 is a tubular body having a substantially constant outer diameter. The tapered portion 42 has an outer diameter that is tapered toward the distal side. The inclination angle α1 with respect to the central axis of the tapered portion 42 is appropriately set, and is, for example, 1 to 80 degrees, more preferably 1 to 30 degrees, and further preferably 1 to 10 degrees. The proximal portion 43 of the dilator has a male connector 44 that can be connected to the Y connector on the outer peripheral surface.

Further, the dilator 40 has a first lumen 45 for movably accommodating the puncture device 60 and two second lumens 46 for movably accommodating the positioning portion 20. The first lumen 45 is located at the center of the dilator 40 in a cross section perpendicular to the central axis of the dilator 40. The first lumen 45 penetrates the dilator 40 in the axial direction. The first lumen 45 is open at the most contracted distal end of the tapered portion 42. The second lumen 46 is located radially outwardly from the first lumen 45 in a cross section perpendicular to the central axis of the dilator 40. The distances of each second lumen 46 from the first lumen 45 are equal. The two second lumens 46 are parallel to the central axis of the dilator 40, except in the vicinity of the proximal opening. The two second lumens 46 do not have to be parallel to the central axis of the dilator 40. The plane P passing through both central axes of the second lumen 46 parallel to the central axis of the dilator 40 is separated from the central axis of the first lumen 45. The proximal portion of the second lumen 46 is inclined toward the proximal side in a direction away from the central axis of the dilator 40 and is open on the outer peripheral surface of the dilator 40.

The two second lumens 46 are opened by the inclined tapered surface 42A of the tapered portion 42. The dilator 40 has an accommodating portion 47 in which the second lumen 46 opens in the tapered portion 42. The accommodating portion 47 is a concave portion connecting both openings of the two second lumens 46 along the tapered surface 42A of the tapered portion 42. The accommodating portion 47 can accommodate the distal end of the positioning portion 20. The accommodating portion 47 forms a space having a size capable of accommodating the accommodating positioning portion 20 inside the tapered surface 42A. The inside of the tapered surface 42A means the inside of the outer peripheral surface of the cone in which the tapered surface 42A forms a part. The accommodating portion 47 may not be able to accommodate the accommodating positioning portion 20 inside the tapered surface 42A. The accommodating portion 47 is cut out so as to open distally and radially outward in a range shorter than the total length in the axial direction of the tapered portion 42 and in a range of less than 180 degrees in the circumferential direction. The accommodating portion 47 has a first surface 47A facing distally and a second surface 47B facing radially outward. The second lumen 46 is open on the first surface 47A. The accommodating portion 47 has a space extending from the second lumen 46. Since the accommodating portion 47 is open distally and radially outward, the positioning portion 20 accommodated in the accommodating portion 47 is directed from the tapered portion 42 toward the distal side and the radial outer side of the dilator 40. Can be easily projected.

The first lumen 45 has an inner diameter between the distal distal lumen 45A, the proximal lumen 45B having a larger inner diameter than the distal lumen 45A, and the distal lumen 45A and the proximal lumen 45B. It has a changing central lumen 45C. The inner diameter of the proximal lumen 45B is sufficiently larger than the outer diameter of the puncture device 60. Therefore, the puncture device 60 inserted into the proximal lumen 45B can move smoothly along the inner peripheral surface of the dilator 40. The central lumen 45C smoothly guides the puncture device 60 through the distal lumen 45A to the proximal lumen 45B. The inner diameter of the distal lumen 45A is an inner diameter that allows the puncture device 60 to slide while contacting with a small clearance. Thereby, the dilator 40 can accurately determine the position of the puncture device 60 that moves the distal lumen 45A and projects outward.

The dilator 40 has a bent portion 48 bent at a predetermined angle at a distal portion in a natural state where no external force acts. The bent portion 48 serves to direct the puncture needle 61 of the puncture device 60 inserted into the right atrium R toward the foramen ovale O. The angle β1 of the bent portion 48 with respect to the proximal portion of the dilator 40 is not particularly limited, but is, for example, 10 to 90 degrees, more preferably 30 to 80 degrees, still more preferably 40 to 70 degrees. The length from the distal end of the dilator 40 to the bent portion 48 is appropriately set, and is, for example, 10 to 150 mm, more preferably 15 to 90 mm, still more preferably 20 to 70 mm.

The axial length of the dilator 40 is appropriately set, and is, for example, 500 to 800 mm. The outer diameter of the dilator 40 is appropriately set, and is, for example, 1.0 to 10.0 mm. The inner diameter of the distal lumen 45A is appropriately set, and is, for example, 0.3 to 5.0 mm. The clearance between the inner peripheral surface of the distal lumen 45A and the outer peripheral surface of the puncture device 60 is set as appropriate, and is, for example, 0.01 to 1.00 mm. The inner diameter of the second lumen 46 is appropriately set according to the outer diameter of the positioning portion 20 to be accommodated, and is, for example, 0.1 to 2.0 mm, more preferably 0.2 to 1.0 mm, still more preferably 0. .3 to 0.7 mm.

The constituent material of the dilator 40 is preferably flexible, for example, polyolefins such as polyethylene and polypropylene, polyamides, polyesters such as polyethylene terephthalate, fluoropolymers such as ETFE, PEEK (polyetheretherketone), polyimide, and the like. Shape memory alloys, metals such as stainless steel, tantalum, titanium, platinum, gold, and tungsten can be preferably used. Further, the dilator 40 may include an X-ray contrast-enhancing material or an ultrasonic contrast-enhancing material.

The positioning unit 20 projects distally from the dilator 40 and is in contact with living tissue. As a result, the positioning unit 20 positions the dilator 40 on which the puncture device 60 protrudes at an appropriate position. The positioning unit 20 has a long body 21 penetrating the dilator 40 and an operating unit 30 provided at a proximal portion of the long body 21. The elongated body 21 is formed by folding one elastically deformable wire rod at the distal portion. The elongated body 21 has a contact portion 22 located at a portion where the wire rod is folded back, and two support portions 23 extending proximally from the contact portion 22. The two supports 23 penetrate the second lumen 46. The contact portion 22 can be accommodated in the accommodating portion 47 of the dilator 40. The long body 21 of the positioning portion 20 is curved and shaped. The elongated body 21 is linear in the second lumen 20 (the shape of the second lumen 46), but is curved by protruding from the opening of the second lumen 46, and the dilator 40 of the puncture device 60. It protrudes in a direction different from the direction of protrusion from.

The operation unit 30 has a casing 31 fixed to the proximal portion of the dilator 40 and a slide unit 32. The slide portion 32 is slidably arranged in the casing 31 along the axial direction of the dilator 40. A support portion 23 led out from the second lumen 46 to the proximal side is fixed to the slide portion 32. Therefore, when the slide portion 32 is moved to the proximal side with respect to the casing 31, the support portion 23 moves to the proximal side in the second lumen 46. As a result, the contact portion 22 located on the distal side of the support portion 23 is accommodated in the accommodating portion 47 (see FIGS. 6 (A) and 7 (A)). When the slide portion 32 is moved to the distal side with respect to the casing 31, the support portion 23 moves to the distal side in the second lumen 46. As a result, the contact portion 22 projects distally from the accommodating portion 47 (see FIGS. 6 (B) and 7 (B)). As shown in FIG. 1, a first display unit 33 such as a scale is provided on the outer surface of the casing 31 along a movable range of the slide unit 32. Further, a second display unit 34 paired with the first display unit 33 is provided on the outer surface of the slide unit 32. As a result, the position of the slide portion 32 with respect to the casing 31 can be easily grasped. Therefore, the amount of protrusion of the positioning portion 20 from the dilator 40 can be grasped from the position of the slide portion 32 with respect to the casing 31. The first display unit 33 and the second display unit 34 provided on the casing 31 and the slide unit 32 do not have to be scales, and may be, for example, symbols, figures, characters, or the like. Further, the first display unit 33 may be provided on the outer peripheral surface of the dilator 40 instead of the casing 31.

The distal portion and the abutting portion 22 of the support portion 23 can be accommodated in the dilator 40 as shown in FIGS. 6 (A) and 7 (A). At this time, the contact portion 22 is located in the accommodating portion 47 of the dilator 40. In this housed state, the support part 23 and the contact part 22 are elastically deformed and housed in the dilator 40.

As shown in FIGS. 6B and 7B, the support portion 23 has a support bending portion 24 that bends in a direction away from the plane P in a protruding state protruding from the dilator 40. The bending direction of the support bending portion 24 with respect to the plane P is opposite to the bending direction of the dilator 40 (see FIG. 1). The two support portions 23 have an angle θ (with respect to the plane P) with respect to the central axis of the distal portion of the dilator 40 in the protruding state. The central axis of the distal portion of the dilator 40 coincides with the projecting direction of the puncture device 60 projecting from the dilator 40. Therefore, the support portion 23 in the protruding state extends in a direction different from the protruding direction from the dilator 40 of the puncture device 60. The support portion 23 may not be bent in the direction away from the plane P only by the support bending portion 24, but may be bent in the direction away from the plane P as a whole. By projecting from the second lumen 46, the two support portions 23 spread apart from each other due to their own elastic force (restoring force). As a result, the support portion 23 and the contact portion 22 protruding from the dilator 40 have a substantially U-shape. The contact portion 22 in the protruding state is located on the distal side of the distal end portion of the dilator 40. Further, the contact portion 22 in the protruding state is located apart from the central axis of the distal portion of the dilator 40 outward in the radial direction of the dilator 40.

When the contact portion 22 hits the contact object, as shown in FIGS. 6 (C) and 7 (C), a force toward the proximal side acts on the contact portion 22, and the support portion 23 bends. The bending direction is different from the protruding direction of the puncture device 60 from the dilator 40 and the extending direction of the support portion 23 in the protruding state. For example, the bending direction is a direction perpendicular to the central axis of the dilator 40 and the extending direction of the support portion 22 (the direction in which the two support portions 23 are separated from each other). The two support portions 23 are spread apart from each other as shown in FIG. 7 (B) in the protruding state. Therefore, when the contact portion 22 abuts on the contact object, the two support portions 23 are deformed so as to be further separated from each other as shown in FIG. 7 (C). As a result, the contact portion 22 and the support portion 23 can be deformed along the shape of the contact symmetric object. Further, the two support portions 23 have an angle θ with respect to the central axis of the distal portion of the dilator 40 in the protruding state, as shown in FIG. 6 (B). Therefore, when the contact portion 22 abuts on the contact object, the two support portions 23 are further bent in the direction away from the plane P as shown in FIG. 6C. As a result, the distal end portion of the dilator 40 can be positioned at a position away from the abutting portion 22.

The angle θ of the elongated body 21 is appropriately set, and is, for example, more than 0 degrees and 80 degrees or less, more preferably 0 to 70 degrees, and further preferably 0 to 60 degrees.

The constituent material of the elongated body 21 is preferably flexible, for example, a shape memory alloy to which a shape memory effect or superelasticity is imparted by heat treatment, or a metal such as stainless steel, tantalum, titanium, platinum, gold, or tungsten. , Polyamides such as polyethylene and polypropylene, polyamides, polyesters such as polyethylene terephthalate, fluoropolymers such as ETFE, PEEK (polyetheretherketone), polyimide and the like can be preferably used. As the shape memory alloy, Ni-Ti type, Cu-Al-Ni type, Cu-Zn-Al type and the like can be preferably used. Further, the elongated body 21 may include an X-ray contrast-enhancing material. The X-ray contrast material is preferably formed from, for example, at least one metal or two or more alloys in the group consisting of gold, platinum, iridium, tungsten or their alloys, and silver-palladium alloys. is there. Further, the elongated body 21 may include an ultrasonic contrast-enhancing material. As the ultrasonic contrast material, stainless steel or the like can be used in addition to the above-mentioned X-ray contrast material.

The outer sheath 50 provides an access route for the ablation catheter, as shown in FIGS. 1-5. The outer sheath 50 has a sheath body 51, a hub 54 connected to a proximal portion of the sheath body 51, a port portion 56 communicating with the hub 54, and a valve body 55 inside the hub 54.

The sheath body 51 is a long tube that accommodates the dilator 40 so as to be movable in the axial direction. The sheath body 51 has an inner peripheral surface that smoothly slides with the dilator 40. The sheath body 51 naturally has a sheath bent portion 52 bent at a predetermined angle at the distal portion. The angle β2 of the sheath bending portion 52 with respect to the proximal portion of the sheath body 51 is not particularly limited, but is, for example, 0 to 90 degrees, more preferably 20 to 70 degrees, still more preferably 30 to 60 degrees. The sheath bending portion 52 serves to direct the puncture needle 61 of the puncture device 60 inserted into the right atrium R toward the foramen ovale O.

The sheath body 51 has a sheath tapered portion 53 at the distal end, which is tapered toward the distal side. The lumen of the sheath body 51 is open at the most reduced diameter end of the sheath taper 53. The inclination angle α2 with respect to the central axis of the sheath taper portion 53 is appropriately set, and is, for example, 1 to 15 degrees, more preferably 2 to 10 degrees, and further preferably 3 to 7 degrees. In the sheath assembly 80 in which the dilator 40 is inserted into the outer sheath 50, the sheath tapered portion 53 is located on the proximal side of the tapered portion 42 of the dilator 40 and can be positioned so as to be continuous with the tapered portion 42. The inner peripheral surface of the sheath body 51 preferably has an appropriate clearance with the outer peripheral surface of the dilator 40 so that the outer peripheral surface of the dilator 40 is slidably contacted.

The dilator 40 can penetrate the sheath body 51 over its entire length. Therefore, the axial length of the sheath body 51 is shorter than that of the dilator 40.

The axial length of the sheath body 51 is appropriately set, and is, for example, 400 to 790 mm. The outer diameter of the sheath body 51 is appropriately set, and is, for example, 1.1 to 11.0 mm. The inner diameter of the sheath body 51 is appropriately set, and is, for example, 1.05 to 10.95 mm. The clearance between the inner peripheral surface of the sheath body 51 and the outer peripheral surface of the dilator 40 is appropriately set, and is, for example, 0.01 to 1.00 mm.

The constituent material of the sheath body 51 is preferably a flexible material, for example, polyolefins such as polyethylene and polypropylene, polyamides, polyesters such as polyethylene terephthalate, fluoropolymers such as ETFE, and PEEK (polyetheretherketone). ), Polyimide and the like can be preferably used.

The hub 54 is provided proximal to the sheath body 51 and communicates with the lumen of the sheath body 51. A dilator 40 penetrates the hub 54. The port portion 56 is connected to the hub 54 and communicates with the lumen of the sheath body 51 via the lumen of the hub 54. The port portion 56 has a three-way stopcock 57 at the end. By connecting a syringe or the like to the three-way stopcock 57, the lumen of the sheath body 51 can be primed, or a contrast medium, a drug, or the like can be injected into the sheath body 51.

The valve body 55 is a member for sealing the lumens of the hub 54 and the sheath body 51. The valve body 55 is flexibly deformable and is arranged on the inner peripheral surface of the hub 54. The valve body 55 is slidably in contact with the outer peripheral surface of the dilator 40. Further, the valve body 55 can press the dilator 40 by an elastic force with the dilator 40 inserted to fix the dilator 40 and the outer sheath 50. Even if it is fixed by the valve body 55, it can be relatively moved in the axial direction by gripping the dilator 40 and the outer sheath 50 and applying a force. Further, by pulling out the dilator 40 from the hub 54, the hole in the valve body 55 into which the dilator 40 is inserted is closed, and the lumen of the hub 54 is sealed from the proximal side. The valve body 55 is, for example, a member having a cut in the center of a disk-shaped elastic body. The elastic body is, for example, natural rubber, silicone rubber, various elastomers and the like. The valve body 55 allows the dilator 40 to be inserted and removed, suppresses blood from leaking through the outer sheath 50, and suppresses air from entering the body.

In the state where the dilator 40 and the outer sheath 50 are combined, it is preferable that the positions, bending directions and bending angles of the bending portion 48 and the sheath bending portion 52 are the same or substantially the same. As a result, the puncture needle 61 and the positioning portion 20 can be projected in a desired direction.

Next, a method of making a hole in the foramen ovale O and providing an access route for the ablation catheter will be described using the medical system 10 according to the embodiment.

First, a catheter introducer is percutaneously punctured into a blood vessel by the Seldinger method or the like. Next, the sheath assembly 80 in which the dilator 40 is inserted inside the outer sheath 50 is prepared. The support portion 23 and the contact portion 22 are housed in the dilator 40. The contact portion 22 is located at the accommodating portion 47. Next, the guide wire 90 is inserted into the first lumen 45 of the dilator 40. The sheath assembly 80 is then inserted into the catheter introducer and inserted into the blood vessel. Subsequently, the distal portion of the sheath assembly 80 is gradually pushed to the right atrium R while leading the guide wire 90. Next, the dilator 40 is once inserted from the right atrium R into the superior vena cava along the guide wire 90. Subsequently, when the dilator 40 is retracted and pulled into the right atrium R, as shown in FIGS. 8, 9 (A) and 10 (A), the distal end of the dilator 40 becomes the foramen ovale O. It is naturally guided to the vicinity of. After this, the guide wire 90 is removed from the sheath assembly 80.

Next, the slide portion 32 of the operation portion 30 is moved to the distal side while confirming the positions of the support portion 23 and the contact portion 22 on the X-ray fluoroscopic image. As a result, as shown in FIGS. 9 (B) and 10 (B), the support portion 23 and the contact portion 22 protrude from the dilator 40. At this time, the amount of movement of the slide portion 32 with respect to the casing 31 is adjusted while being grasped by the first display portion 33 and the second display portion 34 (see FIG. 1), whereby the support portion 23 and the contact portion 22 are adjusted. The amount of protrusion can be adjusted. When the support portion 23 and the contact portion 22 are projected from the dilator 40, the support portion 23 bends in a direction away from the plane P. Further, the two support portions 23 spread apart from each other.

Next, the dilator 40 is pushed distally. As a result, as shown in FIGS. 9 (C) and 10 (C), the contact portion 22 comes into contact with the edge portion of the foramen ovale O. The marginal portion of the foramen ovale O is located at the boundary between the thin foramen ovale O and the thick portion of the atrial septum, and the thickness changes greatly in a stepped manner. When the abutting portion 22 abuts on the edge portion of the foramen ovale O, a force in the proximal direction acts on the abutting portion 22, and the supporting portion 23 bends. The two support portions 23 are deformed so as to be separated from each other when the abutting portion 22 abuts on the edge portion of the foramen ovale O. As a result, the contact portion 22 and the support portion 23 are deformed along the edge portion of the foramen ovale O. Further, when the abutting portion 22 abuts on the edge portion of the foramen ovale O, the two supporting portions 23 are further bent in the direction away from the plane P, that is, toward the proximal side. The contact portion 22 moves in a direction away from the central axis of the dilator 40 while moving toward the proximal side. As a result, the distal end portion of the dilator 40 can be abutted at an optimum position separated from the marginal portion of the foramen ovale O by a predetermined distance. Then, the shapes of the support portion 23 and the contact portion 22 are confirmed by an X-ray contrast image. The support portion 23 and the contact portion 22 are deformed along the edge portion of the foramen ovale O. Therefore, by confirming the shapes of the support portion 23 and the contact portion 22 under fluoroscopy, the shape of the marginal portion of the foramen ovale O can be grasped. Further, since the support portion 23 and the contact portion 22 come into contact with the marginal portion of the foramen ovale O in a wide range, the burden on the living body can be reduced. Then, by confirming the deformed and expanded shape of the support portion 23 and the contact portion 22 on the X-ray fluoroscopic image, it can be recognized that the dilator 40 is arranged at a desired position. Therefore, it is not necessary to use an intracardiac echocatheter (ICE). In addition, in order to further enhance safety, an intracardiac echocatheter may be used in combination.

The proper position of the dilator 40 with respect to the foramen ovale O depends on the procedure. In the procedure described here, it is preferable to puncture the lower part of the foramen ovale O so that the ablation catheter can be easily guided to the pulmonary vein of the left atrium L. Further, for example, in a procedure for treating the mitral valve, it is preferable to puncture the upper part of the fossa ovalis O so that the catheter can be easily guided to the mitral valve. In this medical system 10, the dilator 40 is appropriately adjusted according to the procedure by adjusting the amount of protrusion of the support portion 23 and the contact portion 22, the angle and shape with respect to the foramen ovale, the position in the right atrium R, and the like. Can be positioned in position.

Subsequently, when the dilator 40 is pushed to the distal side, the foramen ovale O is pushed to the left atrium L side and is in a protruding state. At this time, since the outer sheath 50 and the distal portion of the dilator 40 are bent, the distal end portion of the dilator 40 tends to face the foramen ovale O. The foramen ovale O does not have to be in a state of protruding toward the left atrium L side.

Next, as shown in FIGS. 9D and 10C, the puncture device 60 is inserted into the first lumen 45 from the proximal side of the dilator 40 and protrudes from the distal end of the dilator 40. Let me. As a result, the puncture needle 61 punctures the foramen ovale O. At this time, the distal end of the dilator 40 is positioned at an appropriate position. Therefore, it is possible to prevent the puncture needle 61 from erroneously puncturing an unintended position. Further, since the support portion 23 and the contact portion 22 match the shape of the foramen ovale O, the displacement of the support portion 23 and the contact portion 22 from the foramen ovale O is suppressed. As a result, the position of the dilator 40 is less likely to shift, and erroneous puncture can be suppressed.

When the puncture needle 61 penetrates the foramen ovale O, a part of the distal end of the dilator 40 that has pressed the foramen ovale O toward the left atrium L side enters the hole made in the foramen ovale O. .. It is not necessary for a part of the dilator 40 to enter the hole of the foramen ovale O.

Next, as shown in FIG. 11A, the slide portion 32 located outside the body is moved to the proximal side. As a result, the support portion 23 and the contact portion 22 are elastically deformed and accommodated in the dilator 40.

Next, the dilator 40 is pushed distally along the puncture device 60. As a result, as shown in FIG. 11B, the tapered portion 42 of the dilator 40 and the sheath tapered portion 53 of the outer sheath 50 pass through the foramen ovale O while expanding the hole of the foramen ovale O, and the left atrium L To reach. At this time, since the tapered portion 42 and the sheath tapered portion 53 are reduced in diameter toward the distal side, the hole of the foramen ovale O can be smoothly expanded. Further, when the foramen ovale O is punctured by the puncture needle 61, a part of the tapered portion 42 of the dilator 40 has entered the hole of the foramen ovale O. Therefore, it is easy to push the dilator 40 and the outer sheath 50 into the hole of the foramen ovale O. Further, the contact portion 22 is accommodated in the accommodating portion 47 and is located inside the tapered surface 42A. Therefore, the contact portion 22 does not interfere with pushing the dilator 40 into the hole.

Next, the puncture device 60 is removed from the dilator 40. Subsequently, as shown in FIG. 11 (D), the dilator 40 is removed from the body, leaving the outer sheath 50. The foramen ovale O hole widened by the dilator 40 is maintained by the outer sheath 50. When the dilator 40 is removed from the outer sheath 50, the valve body 55 is closed, and blood leakage and air and the like can be suppressed from entering the blood vessel. After that, the ablation catheter is inserted from the proximal side of the outer sheath 50 via the valve body 55. Thereby, the ablation catheter can be inserted into the left atrium L by utilizing the outer sheath 50 penetrating the foramen ovale O. After ablation in the left atrium L with an ablation catheter, when the ablation catheter and the outer sheath 50 are removed from the body, the hole in the foramen ovale O contracts. This completes the procedure.

As described above, the medical system 10 according to the first embodiment is inserted into the living lumen (blood vessel, vasa vasorum, etc.), punctures the atrial septum (living tissue), and widens the hole formed by the puncture. A medical system 10 for holding in a punctured state, in which at least one lumen is provided, and a dilator 40 in which the outer diameter of the distal end gradually decreases toward the distal side and a dilator 40 can be inserted. It can be inserted into the outer sheath 50 having a large lumen, the positioning portion 20 which is movable in the axial direction on the dilator 40 and can project to the distal side of the dilator 40, and the first lumen 45 of the dilator 40. It has a long puncture device 60, and the positioning portion 20 projects in a direction different from the projection direction of the puncture device 60 from the dilator 40.

In the medical system 10 configured as described above, the positioning portion 20 can be projected to the distal side of the dilator 40 and brought into contact with the marginal portion of the foramen ovale O (recess) of the atrial septum. At this time, since the positioning portion 20 protrudes in a direction different from the protruding direction of the puncture device 60, by pushing the dilator 40, the positioning portion 20 comes into contact with the edge portion of the foramen ovale O, and the positioning portion 20 makes the dilator 20. Located away from 40. Therefore, by pushing the dilator 40, the dilator 40 can be positioned at an appropriate position appropriately separated from the marginal portion of the foramen ovale O. Therefore, an appropriate position can be punctured by the puncture device 60, erroneous puncture can be suppressed, and safety can be enhanced. Further, the dilator 40 can be accurately positioned with respect to the foramen ovale O by grasping the position of the positioning portion 20 from the fluoroscopic image or the sensation of the hand. Therefore, erroneous puncture can be suppressed without using an intracardiac echocatheter (ICE). This simplifies the procedure, reduces the number of devices required, and reduces the physical and financial burden on the patient.

Further, the positioning portion 20 has a long support portion 23 that can protrude from the dilator 40 and is elastically deformable, and a contact portion 22 that is supported by a distal portion of the support portion 23. As a result, the positioning portion 20 can be projected to the distal side of the dilator 40, and the contact portion 22 can be aligned with the marginal portion of the foramen ovale O of the atrial septum while elastically deforming the support portion 23. it can. At this time, since the support portion 23 protrudes in a direction different from the protruding direction of the puncture device 60, the contact portion 22 comes into contact with the edge portion of the foramen ovale O by pushing the dilator 40, and the support portion 23 comes into contact with the edge portion. It bends away from the dilator 40. Therefore, by pushing the dilator 40, the dilator 40 can be positioned at an appropriate position appropriately separated from the marginal portion of the foramen ovale O. Therefore, an appropriate position can be punctured by the puncture device 60, erroneous puncture can be suppressed, and safety can be enhanced. Further, the dilator 40 can be accurately positioned with respect to the foramen ovale O by grasping the shape change of the support portion 23 or the contact portion 22 from the fluoroscopic image or the sensation of the hand. Therefore, erroneous puncture can be suppressed without using an intracardiac echocatheter (ICE). This simplifies the procedure, reduces the number of devices required, and reduces the physical and financial burden on the patient.

Further, the dilator 40 has a bent portion 48 that bends to one side toward the distal side, and the bent portion 48 is distal in the direction in which the extending direction of the support portion 23 is inclined with respect to the protruding direction of the puncture device 60. The direction is opposite to the direction of turning toward the side. As a result, when the contact portion 22 is aligned with the marginal portion of the foramen ovale O, the dilator 40 abuts on the foramen ovale O at an appropriate angle. Therefore, the puncture device 60 can puncture the foramen ovale O at an appropriate position in an appropriate direction.

Further, the positioning portion 20 is formed by the elongated body 21 folded back at the distal portion, and the folded portion of the elongated body 21 forms the contact portion 22 from the folded portion of the elongated body 21. The two elongated sites extending proximally form the support portion 23. As a result, by pushing the positioning portion 20 toward the distal side in a protruding state, both the support portion 23 and the contact portion 22 are bent as one long body 21, and the margin of the foramen ovale O is formed. It deforms along the part. Therefore, the positioning portion 20 naturally contacts the edge portion of the foramen ovale O so that the dilator 40 can be positioned at an appropriate position.

Further, the dilator 40 is formed with a second lumen 46 that movably accommodates the positioning portion 20. As a result, the positioning unit 20 is housed in the second lumen 46, and it is possible to prevent the positioning unit 20 from interfering with other devices such as the puncture device 60.

Further, a concave accommodating portion 47 capable of accommodating the abutting portion 22 is formed on the outer peripheral surface of the distal portion of the dilator 40, and the second lumen 46 is opened at the accommodating portion 47. As a result, when the dilator 40 is inserted into the hole formed in the foramen ovale O by the puncture device 60, the contact portion 22 can be accommodated in the accommodating portion 47. Therefore, it is possible to prevent the contact portion 22 from interfering with the insertion of the dilator 40 into the hole. Therefore, the dilator 40 can be smoothly inserted into the hole formed in the foramen ovale O.

Further, the medical device included in the present embodiment is a medical device that is inserted into a living lumen (blood vessel, vasa vasorum, etc.) to widen the hole of the oviduct O (living tissue) in the axial direction. A dilator 40 having a first lumen 45 penetrating and having a tapered portion 42 (reduced diameter portion) whose outer diameter decreases toward the distal side at the distal end, and a shaft of the dilator 40 on the dilator 40. It has a positioning portion 20 that is movably arranged in a direction and can project from the tapered portion 42 to the distal side of the dilator 40, and the positioning portion 20 extends in a direction different from that of the first lumen 45. To do.

In the medical device configured as described above, the positioning portion 20 can be projected to the distal side of the dilator 40 and brought into contact with the marginal portion of the foramen ovale O (recess) of the atrial septum. At this time, since the positioning portion 20 projects in a direction different from that of the first lumen 45, by pushing the dilator 40, the positioning portion 20 comes into contact with the edge portion of the foramen ovale O, and the positioning portion 20 comes into contact with the dilator 40. Located away from. Therefore, by pushing the dilator 40, the dilator 40 can be positioned at an appropriate position appropriately separated from the marginal portion of the foramen ovale O. Therefore, by projecting the puncture device 60 from the first lumen 45, an appropriate position can be punctured by the puncture device 60, and erroneous puncture can be suppressed and safety can be enhanced. Further, the dilator 40 can be accurately positioned with respect to the foramen ovale O by grasping the position of the positioning portion 20 from the fluoroscopic image or the sensation of the hand. Therefore, erroneous puncture can be suppressed without using an intracardiac echocatheter (ICE). This simplifies the procedure, reduces the number of devices required, and reduces the physical and financial burden on the patient. Further, since the positioning portion 20 can protrude from the tapered portion 42, the portion located at the distal portion of the tapered portion 42 and in contact with the foramen ovale O can be positioned with high accuracy. Further, since the positioning portion 20 can project from the tapered portion 42, the positioning portion 20 tends to project in a direction different from that of the first lumen 45 while moving toward the distal side. Further, since the positioning portion 20 can protrude from the tapered portion 42, it is possible to suppress interference with the outer sheath 50 accommodating the dilator 40.

Further, in the dilator 40, a second lumen 46 is formed along the central axis. As a result, the second lumen 46 is housed in the positioning unit 20, and the positioning unit 20 can be prevented from interfering with other devices such as the puncture device 60.

Further, a concave accommodating portion 47 capable of accommodating the abutting portion 22 is formed in the tapered portion 42 (diameter reduced portion), and a second lumen 46 is opened at the accommodating portion 47. As a result, when the dilator 40 is inserted into the hole formed in the foramen ovale O, the contact portion 22 of the positioning portion 20 can be accommodated in the accommodating portion 47. Therefore, it is possible to prevent the positioning portion 20 from hindering the insertion. Therefore, the dilator 40 can be smoothly inserted into the hole formed in the foramen ovale O.

Further, the dilator 40 of the medical device has a bent portion 48 that bends to one side toward the distal side, and the extending direction of the support portion 23 protruding from the dilator 40 is relative to the extending direction of the first lumen 45. The direction of tilting is opposite to the direction in which the bent portion 48 bends toward the distal side. As a result, when the contact portion 22 is projected from the dilator 40 and is aligned with the marginal portion of the foramen ovale O, the dilator 40 abuts on the foramen ovale O at an appropriate angle. Therefore, the puncture device 60 protruding from the first lumen 45 can puncture an appropriate position of the foramen ovale O in an appropriate direction.

Further, the dilator 40 included in the present embodiment is a dilator 40 for expanding a hole formed in the foramen ovale O (living tissue) by forming a first lumen 45 penetrating in the axial direction, and is a dilator 40. A second lumen 46 is formed along the central axis of the dilator 40, and a concave accommodating portion 47 through which the second lumen 46 opens is formed on the outer peripheral surface of the distal portion of the dilator 40.

The dilator 40 configured as described above can movably accommodate the puncture device 60 in the first lumen 45, and can movably accommodate the positioning portion 20 in the second lumen 46. Therefore, an appropriate position can be punctured by the puncture device 60, erroneous puncture can be suppressed, and safety can be enhanced. Further, since the second lumen 46 is opened at the accommodating portion 47, when the dilator 40 is inserted into the hole formed in the foramen ovale O by the puncture device 60, the portion on the distal side of the positioning portion 20 ( The contact portion 22) can be accommodated in the accommodating portion 47. Therefore, it is possible to prevent the positioning portion 20 from hindering the insertion. Therefore, the dilator 40 can be smoothly inserted into the hole formed in the foramen ovale O.

Further, the dilator 40 has a bent portion 48 that bends to one side toward the distal side, and the bent portion 48 is directed toward the distal side in the direction in which the accommodating portion 47 is located with respect to the central axis of the dilator 40. The direction is opposite to the direction of bending. As a result, when the contact portion 22 is projected from the accommodating portion 47 and is aligned with the marginal portion of the foramen ovale O, the dilator 40 abuts on the foramen ovale O at an appropriate angle. Therefore, the puncture device 60 can puncture the foramen ovale O at an appropriate position in an appropriate direction.

The present invention also provides a treatment method (treatment method) for puncturing the foramen ovale O (living tissue) in the living body using the above-mentioned medical system 10 and holding the formed hole in a widened state. Including. The treatment method includes a step of inserting the dilator 40 and the outer sheath 50 into the living lumen, a step of bringing the positioning portion 20 into contact with the marginal portion of the foramen ovale O, and a first step of the puncture device 60 of the dilator 40. A step of puncturing the foramen ovale O to form a hole by projecting from the lumen 45 of the above to the distal side, a step of inserting the dilator 40 and the outer sheath 50 into the hole formed in the foramen ovale O, and the outer sheath 50. It has a step of removing the dilator 40 from the surface.

In the treatment method configured as described above, the positioning portion 20 can be projected to the distal side of the dilator 40 so as to be along the marginal portion of the foramen ovale O. At this time, since the positioning portion 20 projects in a direction different from the protruding direction of the puncture device 60, by pushing the dilator 40, the dilator 40 is positioned at an appropriate position appropriately separated from the edge portion of the foramen ovale O. it can. Therefore, the appropriate position of the foramen ovale O can be punctured by the puncture device 60, and erroneous puncture can be suppressed and safety can be enhanced. In addition, since the dilator 40 can be accurately positioned with respect to the foramen ovale O by the fluoroscopic image or the sensation of the hand, erroneous puncture can be suppressed without using an intracardiac echocatheter (ICE). This simplifies the procedure and reduces the need for devices, reducing the physical and financial burden on the patient.

The present invention is not limited to the above-described embodiment, and various modifications can be made by those skilled in the art within the technical idea of the present invention. For example, the medical system 10 described above may be used to puncture a living tissue other than the foramen ovale O.

Further, the support portion 23 of the positioning portion 20 does not have to be bent so as to be separated from the plane P in a natural state in which an external force does not act. That is, the support portion 23 may be linear in a natural state. In this case, as in the first modification shown in FIG. 12, the second lumen 46A of the dilator 40 may be bent in the vicinity of the opening on the distal side in a direction away from the central axis of the dilator 40. .. As a result, the support portion 23 can protrude in the direction away from the central axis of the dilator 40 while being forcibly bent by the inner peripheral surface of the dilator 40 inside the second lumen 46A. That is, the support portion 23 is separated from the central axis of the dilator 40 by a portion (non-linear second lumen 46A) that prevents the support portion 23 from protruding linearly even if the support portion 23 is linear in the natural state. Can protrude in the direction.

Further, the support portion 23 may be accommodated in the groove 49 on the outer peripheral surface of the dilator 40 as in the second modification shown in FIG. 13 (A). Further, as in the third modification shown in FIG. 13B, the second lumen 46B in which the two support portions 23 are accommodated is one lumen capable of accommodating the two support portions 23 together. May be good. In this case, the contact portion 22 can be accommodated inside the second lumen 46B. Further, as in the fourth modification shown in FIG. 13C, the support portion 23 may be accommodated in the groove 46C on the inner peripheral surface of the dilator 40.

Further, the support portion 23 may be housed in a second lumen 58 formed on the outer sheath 50 as in the fifth modification shown in FIG. 14 (A). Further, the support portion 23 may be housed in a groove 59 formed on the inner peripheral surface of the outer sheath 50 as in the sixth modification shown in FIG. 14 (B). Further, the positioning portion 20 may be accommodated in both the groove on the outer peripheral surface of the dilator 40 and the groove on the inner peripheral surface of the outer sheath 50.

Further, as in the seventh modification shown in FIG. 15, the position where the positioning portion 20 protrudes from the dilator 40 does not have to be the tapered portion 42. Then, when the dilator 40 is bent, the contact portion 22 in the protruding state may have an angle θ with respect to the central axis of the distal portion of the dilator 40.

Further, the contact portion 22 may be a member different from the support portion 23 as in the eighth modification shown in FIGS. 16A and 17A. The contact portion 22A has a higher bending rigidity than the support portion 23. The margin of the foramen ovale O varies from individual to individual and may be formed deep into the tissue of the atrial septum. In this case, since the abutting portion 22A has high rigidity, the abutting portion 22A is less likely to be deformed, and it is possible to prevent the abutting portion 22 from entering too far. When the contact portion 22A does not go too far, the support portion 23 can be appropriately bent and the dilator 40 can be appropriately positioned as shown in FIGS. 16 (B) and 17 (B). The support portion 23 and the contact portion 22A having different shapes may be different members, but may have different shapes by processing one wire rod.

Further, as in the ninth modification shown in FIG. 18A, the contact portion 22B has the contact portion 22B provided at the distal portion of the two support portions 23, and the two support portions 23 are located at the contact portion 22B. It may be inclined at an angle γ with respect to the surface to be formed. In this case, the direction in which the contact portion 22B extends may have an angle of more than 90 degrees with respect to the axial direction of the distal portion of the dilator 40. In this case, it is possible to prevent the contact portion 22B from coming into contact with the marginal portion of the foramen ovale O on a wide surface and entering too far into the marginal portion. As a result, as shown in FIG. 18B, the support portion 23 is appropriately bent, and the dilator 40 can be appropriately positioned. The contact portion 22 may be a separate member from the support portion 23, but may be composed of the same member (wire rod).

Further, as in the tenth modification shown in FIG. 19, the accommodating portion 70 may have a shape that follows the curved shape of the support portion 23 and the contact portion 22. The accommodating portion 70 forms a substantially U-shaped space that is folded back on the distal side on the outer surface of the tapered portion 42. As a result, the support portion 23 and the contact portion 22 housed in the accommodating portion 70 can reduce the concave portions and the convex portions on the tapered surface 42A as much as possible. Therefore, when the dilator 40 is inserted into the hole formed in the foramen ovale O, it is possible to prevent the positioning portion 20 from hindering the insertion. Therefore, the dilator 40 can be smoothly inserted into the hole formed in the foramen ovale O.

Further, the accommodating portion of the dilator may be a part of a second lumen or groove formed in the dilator. That is, the accommodating portion in which the second lumen or groove opens does not have to expand in space with respect to the second lumen or groove.

Further, the number of support portions is not limited to two, and may be one or three or more. Further, the support portion and the contact portion may be a single wire rod that is linear or curved in a natural state.

10 medical system,
20 Positioning part,
21 long body,
22 Contact part,
23 Support,
24 Support bend,
40 dilator,
42 Tapered part (reduced diameter part),
42A tapered surface,
45 First lumen,
46, 46A, 46B, 58 Second lumen,
46C, 49, 59 grooves,
47, 70 containment,
48 Bending part,
50 outer sheath,
60 puncture device,
O Foramen ovale (recess),
L left atrium,
R right atrium,
θ angle.

Claims (9)

It is a medical system that is inserted into the lumen of a living body to puncture a living tissue and hold the formed hole in a widened state.
A dilator having a first lumen that penetrates in the axial direction and a reduced diameter at the distal end where the outer diameter decreases towards the distal side.
An outer sheath having a lumen into which the dilator can be inserted, and
A positioning unit that is movable in the axial direction on the dilator and can project to the distal side of the dilator.
It has a long puncture device that can be inserted into the first lumen of the dilator.
The dilator along the central axis two second rumen emissions formed,
Said second rumen down is open at the reduced diameter portion,
The positioning portion includes two long support portions that can project from each of the second lumens of the dilator and are elastically deformable, and an abutting portion that is supported by a distal portion of the support portion. And have
A concave accommodating portion capable of accommodating the abutting portion is formed in the reduced diameter portion.
A medical system in which the two second lumens are common and open in the containment. The medical system according to claim 1, wherein the distal portion of the second lumen extends away from the central axis of the dilator toward the distal opening. The dilator has a bend that bends unilaterally towards the distal side.
The first or second aspect of claim 1 or 2, wherein the direction in which the support portion protruding from the dilator is inclined with respect to the protrusion direction of the puncture device is the direction opposite to the direction in which the bending portion bends toward the distal side. Medical system. The positioning portion is formed of a wire rod folded back at the distal portion.
The folded portion of the wire rod forms the contact portion and forms the contact portion.
The medical system according to any one of claims 1 to 3, wherein the two elongated parts extending proximally from the folded part of the wire rod form the support part. The dilator has a bend that bends unilaterally towards the distal side.
The position where the second rumen emissions are open at the reduced diameter portion, relative to the central axis of the dilator, claim 1, wherein the bending portion is disposed on the opposite side of bending direction toward the distal side The medical system according to any one of 4. A medical device that is inserted into the lumen of a living body to widen the pores of living tissue.
A dilator having a first lumen that penetrates in the axial direction and a reduced diameter at the distal end where the outer diameter decreases towards the distal side.
The dilator has a positioning portion that is movably arranged in the axial direction of the dilator and that can project from the reduced diameter portion to the distal side of the dilator.
The dilator along the central axis two second rumen emissions formed,
Said second rumen down is open at the reduced diameter portion,
The positioning portion includes two long support portions that can project from each of the second lumens of the dilator and are elastically deformable, and an abutting portion that is supported by a distal portion of the support portion. And have
A concave accommodating portion capable of accommodating the abutting portion is formed in the reduced diameter portion.
Medical device and the two second lumen that has an opening in the receiving portion in common. The medical device of claim 6 , wherein the distal portion of the second lumen extends away from the central axis of the dilator towards the distal opening. The dilator has a bend that bends unilaterally towards the distal side.
Direction extending direction of the support portion protruding from the dilator is inclined with respect to the extending direction of the first lumen, the bending portion according to claim 6 or the opposite direction to bend towards the distal side 7. The medical device according to 7. The dilator has a bend that bends unilaterally towards the distal side.
Said second rumen emissions are open at the reduced diameter portion position, with respect to a center axis of the dilator, the bending portion according to claim 6 to be arranged in the opposite direction of the bending direction towards the distal 8. The medical device according to any one of 8.

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