Atrial septal puncture device

Abstract

An atrial septal puncture device 1 is provided with: a long core wire 2 that has a body 10 and a leading end 12 thinner than the body 10; an electrode 4 that is connected to the leading end 12; a coil 6 that covers at least a portion of the leading end 12 and at least a portion of the body 10 in the axial direction of the core wire 2; and an electrically insulative coating 8 that covers at least a portion of the core wire 2 and at least a portion of the coil 6 in the axial direction.

Description

Atrial Septal Puncture Device

[0001] The present disclosure relates to an atrial septal puncture device.

[0002] A known procedure for treating arrhythmia involves percutaneously inserting an ablation catheter into the left atrium and ablating (cauterizing) the signal transmission pathway that causes arrhythmia. When ablation is performed in the left atrium, a procedure called atrial septal puncture (Brockenbrough method) is sometimes performed to create a hole in the atrial septum separating the right and left atria so that the ablation catheter can be inserted into the left atrium from the right atrium. Regarding this atrial septal puncture, for example, Patent Document 1 discloses an atrial septal puncture device that applies high frequency waves to the atrial septum to form a through-hole.

[0003] Special Publication No. 2016-509942

[0004] As a result of extensive research into atrial septal puncture, the present inventors have come up with a technique that can simplify the procedure for atrial septal puncture.

[0005] The present disclosure has been made in light of these circumstances, and its purpose is to provide a technique for simplifying the procedure for atrial septal puncture.

[0006] One aspect of the present disclosure is an atrial septal puncture device comprising: a main body portion; an elongated core wire having a tip portion located distal to the main body portion and thinner than the main body portion; an electrode connected to the tip portion; a coil covering at least a portion of the tip portion and at least a portion of the main body portion in the axial direction of the core wire; and an insulating coating covering at least a portion of the core wire and at least a portion of the coil in the axial direction.

[0007] Any combination of the above components, and conversion of the expression of the present disclosure into a method, device, system, etc., are also valid aspects of the present disclosure.

[0008] According to the present disclosure, the procedure for atrial septal puncture can be simplified.

[0009] 1A is a side view of an atrial septum puncture device according to an embodiment, FIG 1B is a front view of the atrial septum puncture device, and FIG 1B is a cross-sectional view taken along line AA in FIG 1A.

[0010] The present disclosure will be described below with reference to the drawings based on preferred embodiments. The embodiments are illustrative and do not limit the present disclosure, and all features and combinations thereof described in the embodiments are not necessarily essential to the present disclosure. The same or equivalent components, parts, and processes shown in each drawing are designated by the same reference numerals, and redundant descriptions will be omitted where appropriate. The scale and shape of each part shown in each drawing are set for convenience to facilitate explanation and should not be interpreted as limiting unless otherwise specified. Furthermore, when terms such as "first" and "second" are used in this specification or claims, unless otherwise specified, these terms do not represent any order or importance, but are intended to distinguish one configuration from another. Furthermore, some components that are not important for explaining the embodiments are omitted from each drawing.

[0011] Fig. 1(A) is a side view of an atrial septum puncture device 1 according to an embodiment. Fig. 1(B) is a front view of the atrial septum puncture device 1. Fig. 2 is a cross-sectional view taken along line A-A in Fig. 1(A). The atrial septum puncture device 1 includes a core wire 2, an electrode 4, a coil 6, and an insulating coating 8.

[0012] The core wire 2 is a long, elastic, and conductive member that is inserted into the patient's body from the distal end. Examples of materials that make up the core wire 2 include stainless steel and Ni-Ti alloy. The length of the core wire 2 is, for example, 1500 mm to 3000 mm.

[0013] The core wire 2 also has a main body portion 10 and a distal end portion 12 located distal to the main body portion 10. The main body portion 10 and the distal end portion 12 are continuous with each other. For example, the main body portion 10 and the distal end portion 12 are integrally molded. The main body portion 10 in this embodiment extends from the base end of the core wire 2 to the base end of the distal end portion 12. The distal end portion 12 extends from the distal end of the main body portion 10 to the distal end of the core wire 2. The length of the main body portion 10 is, for example, 1400 mm to 2800 mm, and the length of the distal end portion 12 is, for example, 30 mm to 200 mm.

[0014] The tip portion 12 is thinner than the main body portion 10. In other words, the area of ​​a cross section perpendicular to the axial direction of the core wire 2 (the direction indicated by arrow X in FIG. 1A ) of the core wire 2 is smaller in the tip portion 12 than in the main body portion 10. In this disclosure, the "axial direction" refers to the direction in which the axis of the core wire 2 extends when the core wire 2 extends linearly, in other words, the longitudinal direction of the core wire 2. Hereinafter, the area of ​​a cross section perpendicular to the axial direction of the core wire 2 will be referred to simply as the "cross-sectional area" as appropriate.

[0015] The flexibility of the tip portion 12 can be increased by making the tip portion 12 thinner than the main body portion 10. This makes the tip portion 12 more flexible, making it easier to flex the direction of travel of the atrial septum puncture device 1.

[0016] Furthermore, the tip portion 12 includes a curved portion (not shown) that is curved when no external force is applied. Because the tip portion 12 includes the curved portion, the tip of the atrial septum puncture device 1 naturally curves when the atrial septum puncture device 1 punctures the atrial septum and enters the left atrium. This makes it possible to prevent the tip of the atrial septum puncture device 1 from coming into contact with the left atrium and damaging the left atrium.

[0017] The main body 10 has a cylindrical portion 14. The cylindrical portion 14 is formed, for example, from a round wire. In this embodiment, the main body 10 is formed from the cylindrical portion 14 of a substantially uniform thickness throughout. The diameter or cross-sectional area of ​​the core wire 2 is greatest at the main body 10. In other words, in this disclosure, "the tip portion 12 is thinner than the main body 10" means that the portion of the core wire 2 with the largest outer diameter or largest cross-sectional area is located at the main body 10. The diameter of the main body 10 is, for example, approximately 0.55 mm to 0.90 mm or 0.025 inches to 0.038 inches.

[0018] The distal end portion 12 has a tapered portion 16 and a flattened portion 18. The tapered portion 16 is made of, for example, a round wire and extends from the distal end of the main body portion 10 to the proximal end of the flattened portion 18. The tapered portion 16 has a shape in which the diameter gradually decreases from the proximal end of the core wire 2 to the distal end, i.e., a conical shape. Note that the tapered portion 16 may gradually change from a round wire to a rectangular wire from the proximal end to the distal end of the core wire 2. In this disclosure, the "shape in which the diameter gradually decreases" can be rephrased as "a shape in which the cross-sectional area gradually decreases."

[0019] The flat portion 18 includes a pair of opposing flat surfaces and extends from the tip of the tapered portion 16 to the tip of the core wire 2. The flat portion 18 is made of, for example, a rectangular wire. The flat portion 18 limits the bending direction of the tip portion 12 to the direction in which the two flat surfaces of the flat portion 18 face. This makes it easier to operate the atrial septum puncture device 1. The flat portion 18 is also disposed at the bending portion of the tip portion 12, and is oriented so that one flat surface faces the inside of the bending portion and the other flat surface faces the outside of the bending portion. This makes it easier to bend the bending portion.

[0020] The electrode 4 is connected to the tip portion 12. In this embodiment, the electrode 4 is fixed to the tip of the core wire 2, i.e., the tip of the flat portion 18. The electrode 4 is made of a highly conductive metal such as copper, stainless steel, platinum, gold, or iridium. The electrode 4 is also electrically connected to the core wire 2. As an example, the electrode 4 is integrally molded with the core wire 2.

[0021] The coil 6 is made of a spirally wound wire. In this embodiment, the coil 6 is a flat wire coil wound with a rectangular wire, but it may also be a round wire coil wound with a round wire. The coil 6 covers at least a portion of the distal end portion 12 and at least a portion of the main body portion 10 in the axial direction of the core wire 2. Therefore, the coil 6 is wound not only around the distal end portion 12 but also around the maximum outer diameter portion of the core wire 2.

[0022] Preferably, the coil 6 extends from the tip of the distal end portion 12 to at least partway through the main body portion 10. In this embodiment, the coil 6 extends from the tip of the distal end portion 12 to the base end of the main body portion 10. The portion of the coil 6 that overlaps with the cylindrical portion 14 is fixed to the cylindrical portion 14 with, for example, an adhesive. In the axial direction of the core wire 2, the length of the region of the core wire 2 covered by the coil 6 is preferably 100 mm or more, for example, 1800 mm.

[0023] By covering the tip portion 12 with the coil 6, it is possible to eliminate or at least reduce the difference in thickness between the extension region of the tip portion 12 and the extension region of the main body portion 10 in the atrial septum puncture device 1. In other words, it is possible to make the thickness of the atrial septum puncture device 1 uniform. This makes it easier to insert instruments such as a dilator or sheath into the body along the atrial septum puncture device 1. In particular, when the coil 6 extends from the tip of the tip portion 12 to the base end of the main body portion 10, the thickness of the atrial septum puncture device 1 becomes more uniform, making it easier to insert the instruments.

[0024] Because the coil 6 is highly flexible, even if the distal end portion 12 is covered with the coil 6, it is possible to prevent the flexibility of the distal portion of the atrial septum puncture device 1 from being impaired. The coil 6 also covers the main body portion 10 of the core wire 2. Therefore, the proximal portion of the atrial septum puncture device 1 is composed of a round wire and the coil 6. This allows for greater flexibility of the proximal portion of the atrial septum puncture device 1 compared to when the proximal portion of the same thickness is composed only of a round wire.

[0025] The insulating coating 8 covers at least a portion of the core wire 2 and at least a portion of the coil 6 in the axial direction of the core wire 2. In this embodiment, the insulating coating 8 extends from the tip of the distal end portion 12 to partway along the main body portion 10. In the region where the insulating coating 8 extends, the insulating coating 8 covers the entire circumference of the core wire 2 and the coil 6, i.e., the entire circumference of the core wire 2 in the axial direction.

[0026] Therefore, the atrial septum puncture device 1 has a distal conductive portion 20 at its distal end, a proximal conductive portion 22 at its proximal end, and an insulating portion 24 between the distal conductive portion 20 and the proximal conductive portion 22. The electrode 4, which is exposed and not covered by the insulating coating 8, is disposed on the distal conductive portion 20. The proximal conductive portion 22 is disposed with the proximal end of the coil 6 and the main body portion 10, which are exposed and not covered by the insulating coating 8. The proximal conductive portion 22 functions as a terminal to which an external power source (not shown) is connected. The axial length of the distal conductive portion 20 and the proximal conductive portion 22 is, for example, 10 mm.

[0027] The insulating coating 8 is made of a resin tube, such as polytetrafluoroethylene (PTFE), perfluoroalkoxyalkane (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), polyimide (PI), or polyolefin resin, and has insulating and flexible properties. The insulating coating 8 is fixed to the core wire 2 and the coil 6 by, for example, crimping. For example, the insulating coating 8 is made of a tube that shrinks when heated. The insulating coating 8 covering the core wire 2 and the coil 6 is crimped to the core wire 2 and the coil 6 by applying heat to shrink the insulating coating 8. The thickness of the insulating coating 8 is preferably 0.05 mm or more. This ensures that the insulating portion 24 is insulated. For example, the thickness of the insulating coating 8 is the average thickness measured at multiple points along the axial direction of the core wire 2.

[0028] In a conventional atrial septal puncture, a guidewire is first percutaneously inserted into the inferior vena cava and then advanced through a blood vessel to the atrial septum. Next, a sheath containing a dilator is advanced along the guidewire to the atrial septum. The guidewire is then withdrawn from the sheath, and an atrial septal puncture device is inserted into the sheath instead. The sheath and dilator then compress the atrial septum. In other words, the atrial septum is tented. In this state, the electrodes of the atrial septal puncture device are pressed against the atrial septum, and a radio frequency (RF) current is passed through the atrial septum. The magnitude of the power supplied to the atrial septum during atrial septal puncture is, for example, 30 W to 50 W. Assuming an impedance of 1000 Ω to 2500 Ω, the magnitude of the current passed through the atrial septum is approximately 110 mA to approximately 224 mA. This cauterizes the atrial septum, forming a through-hole. The atrial septum puncture device then passes through the through-hole and enters the left atrium. Next, a dilator is inserted into the through-hole to expand it, and the sheath passes through the through-hole and enters the left atrium. Naturally, the insulating coating 8 can maintain its insulating properties under the above-mentioned power or current supply conditions.

[0029] Conventional atrial septal puncture devices have a high rigidity at the proximal end so that the force input by the operator from the proximal end can be easily transmitted to the electrode at the tip. On the other hand, conventional guidewires have a high overall flexibility so that they can be smoothly advanced through the blood vessel. Therefore, conventional atrial septal puncture devices are not suitable for use as guidewires, and conventional guidewires are not suitable for use as atrial septal puncture devices. Therefore, conventional atrial septal puncture requires the use of both a guidewire and a septal puncture device, which inevitably requires the operation of switching between the guidewire and the septal puncture device.

[0030] In contrast, in this embodiment, the proximal portion of the atrial septum puncture device 1 is composed of a round wire and a coil 6. This provides the proximal portion of the atrial septum puncture device 1 with enough rigidity to be used as an atrial septum puncture device, while also providing enough flexibility to be used as a guidewire. Therefore, the atrial septum puncture device 1 of this embodiment can be used both as a guidewire and as an atrial septum puncture device.

[0031] Therefore, atrial septal puncture using the atrial septal puncture device 1 of this embodiment is performed as follows: First, the atrial septal puncture device 1 is percutaneously inserted into the inferior vena cava and then advanced to the atrial septum via a blood vessel. Next, a sheath containing a dilator is advanced along the atrial septal puncture device 1 to the atrial septum. Next, the atrial septum is tented with the sheath and dilator. In this state, the electrode 4 is pressed against the atrial septum, and a high-frequency current is passed through the atrial septum. This cauterizes the atrial septum, forming a through-hole. Then, the atrial septal puncture device 1 passes through the through-hole and advances into the left atrium. Next, the dilator is inserted into the through-hole to expand it, and the sheath passes through the through-hole and advances into the left atrium.

[0032] In this way, when the atrial septum puncture device 1 of this embodiment is used, the step of replacing the guidewire with the atrial septum puncture device can be omitted, thereby simplifying the atrial septum puncture procedure.

[0033] The embodiments of the present disclosure have been described in detail above. The above-described embodiments merely illustrate specific examples of implementing the present disclosure. The content of the embodiments does not limit the technical scope of the present disclosure, and many design modifications, such as changing, adding, or deleting components, are possible within the scope of the concept of the present disclosure defined in the claims. A new embodiment with design modifications will combine the effects of the combined embodiments and modifications. In the above-described embodiments, the content that allows such design modifications is emphasized by using notations such as "in this embodiment" or "in this embodiment," but design modifications are also permitted even in content without such notation. Any combination of the components included in each embodiment is also valid as an aspect of the present disclosure. Hatching on cross sections in the drawings does not limit the material of the hatched object.

[0034] Embodiments may be specified by the following items: [Item 1] An atrial septum puncture device (1) comprising: a main body (10); an elongated core wire (2) having a tip portion (12) located distal to the main body (10) and thinner than the main body (10); an electrode (4) connected to the tip portion (12); a coil (6) covering at least a portion of the tip portion (12) and at least a portion of the main body (10) in the axial direction (X) of the core wire (2); and an insulating coating (8) covering at least a portion of the core wire (2) and at least a portion of the coil (6) in the axial direction (X). [Item 2] The atrial septum puncture device (1) according to Item 1, wherein the length of the region of the core wire (2) covered by the coil (6) in the axial direction (X) is 100 mm or more. [Item 3] The atrial septum puncture device (1) according to item 1 or 2, wherein the distal end (12) has a tapered portion (16) in which the area of ​​a cross section perpendicular to the axial direction (X) gradually decreases from the proximal end side to the distal end side of the core wire (2). [Item 4] The atrial septum puncture device (1) according to any one of items 1 to 3, wherein the distal end (12) has a flattened portion (18) including a pair of opposing flat surfaces. [Item 5] The atrial septum puncture device (1) according to any one of items 1 to 4, wherein the thickness of the insulating coating (8) is 0.05 mm or more.

[0035] The present disclosure can be utilized in an atrial septal puncture device.

[0036] 1 atrial septal puncture device, 2 core wire, 4 electrode, 6 coil, 8 insulating coating, 10 main body portion, 12 tip portion, 14 cylindrical portion, 16 tapered portion, 18 flattened portion.

Claims

1. An atrial septum puncture device comprising: a main body; a long core wire having a tip end that is located distal to the main body and thinner than the main body; an electrode connected to the tip end; a coil that covers at least a portion of the tip end and at least a portion of the main body in the axial direction of the core wire; and an insulating coating that covers at least a portion of the core wire and at least a portion of the coil in the axial direction.

2. The atrial septal puncture device according to claim 1, wherein the length of the region of the core wire covered by the coil in the axial direction is 100 mm or more.

3. An atrial septum puncture device according to claim 1 or 2, wherein the distal end portion has a tapered portion in which the area of ​​a cross section perpendicular to the axial direction gradually decreases from the base end side to the distal end side of the core wire.

4. The atrial septum puncture device according to claim 1 or 2, wherein the tip portion has a flattened portion including a pair of opposing flat surfaces.

5. The atrial septal puncture device according to claim 1 or 2, wherein the insulating coating has a thickness of 0.05 mm or more.

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