WO2022071179A1

WO2022071179A1 - Medical device and shunt forming method

Info

Publication number: WO2022071179A1
Application number: PCT/JP2021/035257
Authority: WO
Inventors: 一成深見
Original assignee: テルモ株式会社
Priority date: 2020-09-29
Filing date: 2021-09-27
Publication date: 2022-04-07
Also published as: JP2023175056A

Abstract

This medical device (10) comprises: an expansion body (21); a shaft part (20) to which a base end of the expansion body (21) is fixed; a plurality of electrode groups (22) provided at intervals in a circumferential direction of the expansion body (21); and a current supply unit (101) that supplies a current to the plurality of electrode groups (22). The expansion body (21) has a recess (51) recessed inward in a radial direction. The recess (51) has a bottom portion (51a), a base end side standing portion (52) extending radially outward from a base end of the bottom portion (51a), and a tip side standing portion (53) extending radially outward from a tip of the bottom portion (51a). Each of the plurality of electrode groups (22) has a base end side electrode (61) disposed in the base end side standing portion (52) and a tip side electrode (62) disposed in the tip side standing portion (53). The current supply unit (101) can independently supply the current to the base end side electrode (61) and the tip side electrode (62).

Description

Medical devices and shunt forming methods

The present invention relates to a medical device and a shunt forming method for imparting energy to a living tissue.

Chronic heart failure is known as one of the heart diseases. Chronic heart failure is roughly classified into systolic failure and diastolic failure based on the index of cardiac function. In patients suffering from diastolic dysfunction, the myocardium becomes hypertrophied and stiffness increases, resulting in an increase in blood pressure in the left atrium and a decrease in the pumping function of the heart. As a result, the patient presents with heart failure symptoms such as pulmonary edema. In addition, there is also a heart disease in which the blood pressure on the right atrium side increases due to pulmonary hypertension or the like, and the pump function of the heart decreases, resulting in heart failure symptoms.

In recent years, shunt treatment that forms a shunt (puncture hole) in the atrial septum, which is an escape route for increased atrial pressure, and enables alleviation of heart failure symptoms has been attracting attention for these patients with heart failure. Shunt treatment uses a transvenous approach to access the atrial septum and form a puncture hole of the desired size. As a medical device for performing shunt treatment for such an atrial septum, for example, there is one listed in Patent Document 1.

International Publication No. 2019-179447

In the medical device of Patent Document 1, a plurality of electrodes are fixed in the recesses of the extended body. The positions of the electrodes in the recess are the same in the axial direction of the expansion body. In this case, when the dilated body is brought into contact with the tissue to be treated, if the angle between the recess and the tissue to be treated is significantly different, the electrode portion may not sufficiently contact the tissue to be treated. If the electrode portion is not sufficiently in contact with the tissue to be treated, sufficient energy cannot be applied to the living tissue, which may reduce the therapeutic effect. Further, if energy is applied while the electrode portion is exposed to blood, there is a risk that a thrombus is formed.

The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a medical device and a shunt forming method capable of suppressing the formation of thrombus and effectively cauterizing. do.

The medical device according to the present invention that achieves the above object includes an expansion body that can be expanded and contracted in the radial direction, a long shaft portion having a tip portion including a proximal end fixing portion in which the proximal end of the extended body is fixed, and a long shaft portion. Along with the expansion body, a plurality of electrode groups provided at intervals in the circumferential direction of the expansion body and a current supply unit for supplying a current to the plurality of electrode groups are provided, and the expansion body has a diameter. It has a recess inward in the direction and defines a receiving space that can receive living tissue when the expanded body is expanded, and the recess has a bottom located at the innermost side in the radial direction and a radial direction from the base end of the bottom. It has a proximal end-side upright portion extending outward and a distal end-side upright portion extending radially outward from the tip of the bottom, and the plurality of electrode groups are respectively located on the proximal end side so as to face the receiving space. The proximal end side electrode arranged in the upright portion and the tip arranged in the distal end side upright portion at substantially the same position as the proximal end side electrode in the circumferential direction of the extended body so as to face the receiving space. It has a side electrode, and the current supply unit can independently supply a current to the base end side electrode and the tip end side electrode.

The shunt forming method according to the present invention that achieves the above object is a tip including an expansion body that can be expanded and contracted in the radial direction including a recess recessed inward in the radial direction, and a base end fixing portion in which the base end of the expansion body is fixed. A long shaft portion having a portion, a plurality of electrode groups provided along the expansion body at intervals in the circumferential direction of the expansion body, and a current supply unit for supplying current to the plurality of electrode groups. A method of forming a shunt in the atrioventricular septum using a medical device equipped with the The base end side erecting portion extending radially outward from the base end of the bottom portion located on the innermost side in the radial direction of the concave portion so that the plurality of electrode groups each face the receiving space. At a position substantially the same as the proximal end side electrode in the circumferential direction of the extended body so as to face the receiving space and the proximal end side electrode arranged in the It has a proximal end side electrode arranged in an upright portion, and the recess is arranged in a puncture hole formed in the atrioventricular septum to receive the biological tissue surrounding the puncture hole in the receiving space. In each of the plurality of electrode groups, the current is applied to an electrode in which at least one of the proximal end electrode or the distal electrode is brought into contact with the biological tissue of the atrioventricular septum and is in contact with the biological tissue of the atrioventricular septum. A current is supplied from the supply unit to cauterize the biological tissue, and no current is supplied to the electrodes that are not in contact with the biological tissue during the cauterization.

The medical device configured as described above does not supply current to the electrodes that are not in contact with the living tissue of each electrode group, but supplies current only to the electrodes that are in contact with the living tissue, so that a thrombus is formed. This can be suppressed and effectively cauterized.

At least one of the base end side electrode or the tip end side electrode may have at least two single electrodes configured to supply current independently of the current supply unit. As a result, the surface area of the proximal end electrode and / or the distal electrode in contact with the living tissue can be easily increased, and the shape of the shunt formed by cauterization can be effectively maintained. Further, by not supplying an electric current to an electrode that does not come into contact with a living tissue, it is possible to effectively suppress the formation of a thrombus.

The medical device may have a determination unit for determining whether or not the electrode is in contact with the contact target. As a result, the electrode to which the current is supplied and the electrode to which the current is not supplied can be automatically determined, so that the operability is improved.

The determination unit may determine whether or not the electrode is in contact with the contact target based on the impedance detected by the electrode. As a result, it can be easily determined whether or not the electrode is in contact with the contact target, so that the operability is improved.

The expansion body has a plurality of wire rod portions defining the recesses so that the recesses have a plurality of recesses arranged at least three at equal intervals in the circumferential direction of the expansion body. Each of the recesses has the bottom portion, the proximal end side upright portion, and the distal end side upright portion, and the plurality of electrode groups may be arranged one by one in each of the plurality of recesses. As a result, the recesses are arranged at equal intervals in the circumferential direction of the dilated body, so that when the tissue around the puncture hole formed in the living body is cauterized, the shape can be made close to a regular polygon. Can form a shunt of the desired size.

In the shunt forming method configured as described above, the current is not supplied to the electrodes that are not in contact with the living tissue of each electrode group, but the current is supplied only by the electrodes that are in contact with the living tissue, so that a thrombus is formed. It can be suppressed and effectively cauterized.

It is a front view which showed the whole structure of the medical device which concerns on embodiment. It is an enlarged perspective view near the extended body. It is an enlarged front view near the extended body. The medical device is a front view and the living tissue is a cross-sectional view, respectively, schematically showing the state in which the dilated body is arranged in the interatrial septum. It is a figure showing the extended body housed in the storage sheath. The medical device is a front view and the biological tissue is a cross-sectional view showing the state in which the dilated body is arranged in the right atrium. It is explanatory drawing which shows the state which expanded the diameter of the dilated body in the interatrial septum from the state of FIG. The medical device is a front view and the living tissue is a cross-sectional view, respectively, schematically showing the state in which the dilated body is arranged in the interatrial septum. It is a flowchart for demonstrating the shunt formation method. It is a front view of the vicinity of the extended body of the 1st modification. It is an enlarged cross-sectional view around the electrode group of the 1st modification. It is a front view of the vicinity of the extended body of the 2nd modification. It is a front view of the vicinity of the extended body of the 3rd modification. It is a front view of the vicinity of the extended body of the 4th modification. It is a front view of the vicinity of the extended body of the 5th modification. It is a front view of the vicinity of the extended body of the 6th modification.

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. Further, in the present specification, the side of the medical device 10 to be inserted into the living body cavity is referred to as "tip" or "tip side", and the hand side to be operated is referred to as "base end" or "base end side".

The medical device according to the following embodiment can perform maintenance measures for expanding the puncture hole Hh formed in the atrial septal HA of the patient's heart H and maintaining the further expanded puncture hole Hh at its size. It is configured as follows.

As shown in FIGS. 1 to 3, the medical device 10 of the present embodiment includes a long shaft portion 20, an expansion body 21 provided at the tip portion of the shaft portion 20, and an energy transfer element for performing maintenance measures. It has a plurality of electrode groups 22, a hand operation unit 23 provided at the base end portion of the shaft portion 20, and an energy supply device 100.

The shaft portion 20 has a tip portion 30 including a base end fixing portion 31 to which the base end of the expansion body 21 is fixed and a tip fixing portion 33 to which the tip end of the expansion body 21 is fixed. The tip portion 30 of the shaft portion 20 has a shaft extension portion 32 extending in the extension body 21 from the base end fixing portion 31. The shaft portion 20 has a storage sheath 25 provided on the outermost peripheral portion. The expansion body 21 can move forward and backward in the axial direction with respect to the storage sheath 25. The storage sheath 25 can store the expansion body 21 inside the storage sheath 25 in a state of being moved to the tip end side of the shaft portion 20. By moving the storage sheath 25 from the state in which the expansion body 21 is stored to the base end side, the expansion body 21 can be exposed.

The shaft portion 20 has a tow shaft 26. The tow shaft 26 is provided from the base end of the shaft portion 20 to the shaft extension portion 32, and the tip portion thereof is fixed to the tip member 35.

The tip member 35 to which the tip of the tow shaft 26 is fixed does not have to be fixed to the expansion body 21. As a result, the tip member 35 can pull the expansion body 21 in the compression direction. Further, when the expansion body 21 is stored in the storage sheath 25, the tip member 35 is separated from the expansion body 21 toward the tip side, so that the expansion body 21 can be easily moved in the extending direction and the storage property can be improved. can.

The hand operation unit 23 has a housing 40 held by the operator, an operation dial 41 that can be rotated by the operator, and a conversion mechanism 42 that operates in conjunction with the rotation of the operation dial 41. The tow shaft 26 is held by the conversion mechanism 42 inside the hand operation unit 23. The conversion mechanism 42 can move the tow shaft 26 to be held forward and backward along the axial direction as the operation dial 41 rotates. As the conversion mechanism 42, for example, a rack and pinion mechanism can be used.

The expansion body 21 has a plurality of wire rod portions 50 in the circumferential direction. In this embodiment, four wire rod portions 50 are provided in the circumferential direction. Each of the wire rod portions 50 can be expanded and contracted in the radial direction. The base end portion of the wire rod portion 50 extends from the base end fixing portion 31 toward the tip end side. The tip portion of the wire rod portion 50 extends from the base end portion of the tip fixing portion 33 toward the base end side. The wire rod portion 50 is inclined so as to increase in the radial direction from both end portions in the axial direction toward the center portion. Further, the wire rod portion 50 has a recess 51 recessed inward in the radial direction of the expansion body 21 in the central portion in the axial direction. The innermost portion in the radial direction of the recess 51 is the bottom portion 51a. The recess 51 defines a receiving space 51b capable of receiving a living tissue when the expanded body 21 is expanded.

Each recess 51 has a base end side upright portion 52 extending radially outward from the base end of the bottom portion 51a, and a tip end side upright portion 53 extending radially outward from the tip end of the bottom portion 51a. The electrode group 22 is arranged in the recess 51 so as to face the receiving space 51b. The tip-side upright portion 53 has a slit-shaped central portion in the width direction, and has outer edge portions 55 on both sides and a back support portion 56 at the central portion.

The wire rod portion 50 forming the expansion body 21 has, for example, a flat plate shape cut out from a cylinder. The wire rod forming the expansion body 21 can have a thickness of 50 to 500 μm and a width of 0.3 to 2.0 mm. However, it may have dimensions outside this range. In addition, the wire rod portion 50 may have a circular cross-sectional shape or a cross-sectional shape other than that.

Each of the electrode groups 22 arranged in the wire rod portion 50 has a proximal end side electrode 61 arranged in the proximal end side upright portion 52 so as to face the receiving space 51b and an distal end side upright so as to face the receiving space 51b. It has a tip side electrode 62 arranged in the portion 53. The base end side electrode 61 and the tip end side electrode 62 are configured to receive an electric current independently.

The base end side electrode 61 and the tip end side electrode 62 are composed of, for example, bipolar electrodes that receive electrical energy from the energy supply device 100. In this case, energization is performed between the electrode groups 22 arranged in each wire rod portion 50. The electrode group 22 and the energy supply device 100 are connected by a conducting wire (not shown) coated with an insulating coating material. The conducting wire is led out to the outside via the shaft portion 20 and the hand operation portion 23, and is connected to the energy supply device 100. The energy supply device 100 may be arranged in the hand operation unit 23.

The electrode group 22 may also be configured as a monopolar electrode. In this case, electricity is supplied to the counter electrode plate prepared outside the body. Further, instead of the electrode group 22, a heat generating element (electrode chip) that receives high frequency electric energy from the energy supply device 100 to generate heat may be used. In this case, energization is performed between the heat generating elements arranged in each wire rod portion 50. Further, the electrode group 22 includes microwave energy, ultrasonic energy, coherent light such as a laser, a heated fluid, a cooled fluid, one that exerts heating and cooling action by a chemical medium, and one that generates frictional heat. It can be configured by an energy transfer element capable of applying energy to the puncture hole Hh, such as a heater provided with an electric wire or the like, and the specific form is not particularly limited.

The wire rod portion 50 can be formed of a metal material. As the metal material, for example, titanium-based (Ti—Ni, Ti—Pd, Ti—Nb—Sn, etc.) alloys, copper-based alloys, stainless steels, β-titanium steels, and Co—Cr alloys can be used. .. It is better to use an alloy having a spring property such as a nickel-titanium alloy. However, the material of the wire rod portion 50 is not limited to these, and may be formed of other materials.

The shaft portion 20 is preferably formed of a material having a certain degree of flexibility. Examples of such a material include polyolefins such as polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or a mixture of two or more thereof, and a soft polyvinyl chloride resin. Examples thereof include fluororesins such as polyamide, polyamide elastomer, polyester, polyester elastomer, polyurethane and polytetrafluoroethylene, polyimide, PEEK, silicone rubber and latex rubber.

The traction shaft 26 includes, for example, a superelastic alloy such as a nickel-titanium alloy or a copper-zinc alloy, a metal material such as stainless steel, a long wire such as a resin material having a relatively high rigidity, and a polyvinyl chloride or polyethylene. , Polyethylene, or a resin material such as an ethylene-propylene copolymer.

The tip member 35 is, for example, a polymer material such as polyolefin, polyvinyl chloride, polyamide, polyamide elastomer, polyurethane, polyurethane elastomer, polyimide, fluororesin, or a mixture thereof, or a multilayer tube of two or more kinds of polymer materials. Can be formed.

As shown in FIG. 5, the expansion body 21 housed in the storage sheath 25 is in a state of being contracted in the radial direction. When the expansion body 21 and the storage sheath 25 move in the axial direction with each other, the expansion body 21 is exposed to the outside of the storage sheath 25 and expands in the radial direction.

As shown in FIG. 1, the shaft portion 20 has a bent portion 20a that is previously bent in one direction at a portion on the proximal end side of the extended body 21. This allows the surgeon to easily direct the tip of the shaft 20 to the site where the atrial septum HA is punctured.

The hand operation unit 23 is provided with a display means so that the operator can grasp the direction of the bent portion 20a inserted into the living body. The hand operation unit 23 is provided with an orientation display unit 80 as a display means. A mark indicating the bending direction of the bending portion 20a is displayed on the orientation display portion 80, and the orientation of the shaft portion 20 inserted in the living body can be recognized.

The hand operation unit 23 has a port 81 for priming the medical device 10. The direction in which the port 81 extends from the hand operating portion 23 is set to be the same as the direction in which the bent portion 20a bends. Also with this, since the operator can recognize the direction of the bent portion 20a, the port 81 may be used as the display means.

The energy supply device 100 has a current supply unit 101 that supplies a current to a plurality of electrode groups 22, and a determination unit 102 that determines whether or not the electrodes are in contact with the contact target. The determination unit 102 is composed of, for example, a CPU (Central Processing Unit), a storage circuit, an operation program, and the like.

The determination unit 102 controls the current supply unit 101 to adjust the output of the high frequency current from the current supply unit 101. The determination unit 102 can output a high-frequency current from the current supply unit 101 at an arbitrary voltage.

The determination unit 102 acquires the value of the output voltage from the current supply unit 101, and also acquires the value of the current detected by the current sensor (not shown) of the current supply unit 101. The determination unit 102 can calculate the bioimpedance value of the contacted portion by dividing the voltage value by the current value.

The current supply unit 101 can independently supply current to the proximal end side electrode 61 and the distal end side electrode 62 of each electrode group 22. Since the medical device 10 according to the present embodiment has eight electrodes including four base end side electrodes 61 and four tip end side electrodes 62, the current supply unit 101 is controlled by the determination unit 102 and has eight electrodes. Can supply current independently to. The determination unit 102 can also independently adjust the value of the voltage supplied to each electrode.

The determination unit 102 determines whether or not the electrodes are in contact with the contact target based on the impedance detected by each electrode. For example, when the impedance is equal to or less than or equal to a preset threshold value, the determination unit 102 can determine that the electrode is exposed to blood without contacting the atrial septal HA to be contacted.

The treatment method using the medical device 10 will be described with reference to the flowchart shown in FIG. The treatment method of this embodiment is performed on a patient suffering from heart failure (left heart failure). More specifically, as shown in FIG. 4, for a patient suffering from chronic heart failure in which the blood pressure of the left atrium HLa increases due to the enlargement of the myocardium of the left ventricle of the heart H and the increase in stiffness (hardness). This is the method of treatment performed.

The treatment method of the present embodiment includes a step of forming a puncture hole Hh in the atrial septal HA, a step of arranging the dilator 21 in the puncture hole Hh (S2), and receiving a living tissue in the receiving space 51b. A step (S3), a step of expanding the diameter of the puncture hole Hh by the dilator 21 (S4), a step of confirming the hemodynamics in the vicinity of the puncture hole Hh (S5), and a step of maintaining the size of the puncture hole Hh. It has a step (S6) for performing the maintenance treatment and a step (S7) for confirming the hemodynamics in the vicinity of the puncture hole Hh after the maintenance treatment is performed.

The surgeon delivers the introducer, which is a combination of a guiding sheath and a dilator, to the vicinity of the atrial septal HA when forming the puncture hole Hh. The introducer can be delivered to the right atrium HRa, for example, via the inferior vena cava Iv. Further, the delivery of the introducer can be performed by using the guide wire 11. The surgeon can insert the guide wire 11 through the dilator and deliver the introducer along the guide wire 11. It should be noted that the insertion of the introducer into the living body, the insertion of the guide wire 11 and the like can be performed by a known method such as using an introducer for introducing a blood vessel.

In the step of S1, the surgeon penetrates a puncture device (not shown) from the right atrium HRa side toward the left atrium HLa side to form a puncture hole Hh. As the puncture device, for example, a device such as a wire having a sharp tip can be used. The puncture device is inserted through a dilator and delivered to the atrial septal HA. The puncture device can be delivered to the atrial septal HA in place of the guide wire 11 after removing the guide wire 11 from the dilator.

In the step of S2, first, as shown in FIG. 4, the medical device 10 is delivered to the vicinity of the atrial septal HA along the guide wire 11 inserted in advance. At this time, the tip of the medical device 10 penetrates the atrial septum HA and reaches the left atrium HLa, as shown in FIG. Further, when the medical device 10 is inserted, the expansion body 21 is in a state of being housed in the storage sheath 25.

Next, in the step of S3, the expansion body 21 is exposed by moving the storage sheath 25 to the base end side. As a result, as shown in FIG. 6, the dilated body 21 is expanded in diameter, the recess 51 is arranged in the puncture hole Hh of the atrial septum HA, and the receiving space 51b receives the biological tissue surrounding the puncture hole Hh. The puncture hole Hh is maintained in the expanded state by the dilator 21.

The shaft portion 20 of the medical device 10 is appropriately operated by the operator while confirming the orientation of the flexion portion 20a by the display means of the hand operation unit 23, so that the tip side thereof becomes the atrial septum HA in the right atrium HRa. Arranged to face. As shown in FIG. 6, in a state where the expansion body 21 is arranged in the puncture hole Hh, the central axis direction of the shaft portion 20 is inclined with respect to the central axis direction of the through hole Hh.

In the step of S4, the operator operates the hand operation unit 23 with the atrial septum HA gripped by the recess 51, moves the traction shaft 26 toward the proximal end side, and as shown in FIG. 7, the dilator 21 The living tissue is sandwiched between the recesses 51 of the above. Since the central axial direction of the shaft portion 20 is inclined with respect to the central axial direction of the through hole Hh, one of the distal end side electrode 62 and the proximal end side electrode 61 in each electrode group 22 comes into contact with the biological tissue. It may not be. It should be noted that "not in contact with the living tissue" may include contacting the living tissue to some extent but hardly contacting the living tissue. The operator operates the energy supply device 100 to detect impedance by each electrode. The determination unit 102 detects the impedance and determines whether or not each electrode is in contact with the living tissue from the detected impedance.

After placing the dilator 21 in the puncture hole Hh, check the hemodynamics in the step of S5. As shown in FIG. 8, the operator delivers the hemodynamic confirmation device 110 to the right atrium HRa via the inferior vena cava Iv. As the hemodynamic confirmation device 110, for example, a known echo catheter can be used. The surgeon can display the echo image acquired by the hemodynamic confirmation device 110 on a display device such as a display, and confirm the blood volume passing through the puncture hole Hh based on the display result.

Next, in the step of S6, the operator performs a maintenance procedure to maintain the size of the puncture hole Hh. In the maintenance procedure, high-frequency energy is applied to the edge of the puncture hole Hh through the electrode group 22, so that the edge of the puncture hole Hh is cauterized (heated and cauterized) by the high-frequency energy.

The operator operates the energy supply device 100 to start cauterization by each electrode. The current supply unit 101 supplies the current only to the electrodes determined by the determination unit 102 to be in contact with the living tissue, and does not supply the current to the electrodes determined not to be in contact with the living tissue. Therefore, in each electrode group 22, when the current is supplied to both the distal end side electrode 62 and the proximal end side electrode 61, and when the current is supplied to only one of the distal end side electrode 62 or the proximal end side electrode 61. There is. If neither the distal end side electrode 62 nor the proximal end side electrode 61 of the electrode group 22 comes into contact with the living tissue, the electrode group 22 may not be used and may be cauterized by another electrode group 22. When the determination unit 102 determines that the current is supplied to both the distal end side electrode 62 and the proximal end side electrode 61, the current supplied to each of the distal end side electrode 62 and the proximal end side electrode 61 is the distal end side electrode 62. Alternatively, the current supply unit 101 may be controlled so as to be smaller than the current when the current is supplied to only one of the base end side electrodes 61. This makes it possible to prevent excessive heat generation of the biological tissue in which a current is passed from both the distal end electrode 62 and the proximal end electrode 61.

The temperature of the living tissue that comes into contact with the electrode to which the current is supplied rises and is cauterized. At this time, since the electrode exposed to blood without contacting the living tissue is not supplied with an electric current, the generation of thrombus can be suppressed.

When the biological tissue near the edge of the puncture hole Hh is cauterized through the electrode group 22, a degenerated portion in which the biological tissue is denatured is formed near the edge. Since the living tissue in the degenerated portion loses its elasticity, the puncture hole Hh can maintain its shape when expanded by the dilator 21.

After the maintenance procedure, as shown in FIG. 8, the hemodynamics are confirmed again in the step of S7, and when the blood volume passing through the puncture hole Hh is the desired amount, the operator reduces the diameter of the dilated body 21. It is stored in the storage sheath 25, and then removed from the puncture hole Hh. Further, the entire medical device 10 is removed from the living body, and the treatment is completed.

In the step of S4, the surgeon may perform cauterization in the state shown in FIG. 6 without sandwiching the living tissue in the recess 51 of the expansion body 21.

As described above, the medical device 10 according to the present embodiment has a long tip portion 30 including an expansion body 21 that can be expanded and contracted in the radial direction and a base end fixing portion 31 to which the base end of the expansion body 21 is fixed. A shaft portion 20, a plurality of electrode groups 22 provided along the expansion body 21 at intervals in the circumferential direction of the expansion body 21, and a current supply unit 101 for supplying a current to the plurality of electrode groups 22. The extended body 21 is provided with a recess 51 that is radially inward and defines a receiving space 51b that can receive living tissue when the expanded body 21 is expanded, and the recess 51 is located on the innermost side in the radial direction. It has a bottom portion 51a, a proximal end side upright portion 52 extending radially outward from the proximal end of the bottom portion 51a, and a distal end side upright portion 53 extending radially outward from the tip end of the bottom portion 51a, and the plurality of electrode groups 22 have a plurality of electrode groups 22. The base end side electrode 61 arranged in the base end side upright portion 52 so as to face the receiving space 51b, and the base end side electrode 61 in the circumferential direction of the extension 21 so as to face the receiving space 51b. The tip side electrode 62 is located at substantially the same position as the tip end side upright portion 53, and the current supply unit 101 can independently supply current to the proximal end side electrode 61 and the tip end side electrode 62. Is.

The medical device 10 configured as described above does not supply a current to the electrodes of each electrode group 22 that are not in contact with the living tissue, but supplies a current only to the electrodes that are in contact with the living tissue, and thus comes into contact with blood. It is possible to suppress the formation of blood clots due to the flow of an electric current through the electrodes, and it is possible to effectively cauterize.

Further, the medical device 10 has a determination unit 102 for determining whether or not the electrode is in contact with the contact target. As a result, the electrode to which the current is supplied and the electrode to which the current is not supplied can be automatically determined, so that the operability of the medical device 10 is improved. The surgeon may be able to determine whether or not the electrode is in contact with the contact target by the surgeon's eyes under X-ray imaging. In this case, the medical device 10 does not have to have the determination unit 102.

Further, the determination unit 102 determines whether or not the electrode is in contact with the contact target based on the impedance detected by the electrode. As a result, it can be easily determined whether or not the electrode is in contact with the contact target, so that the operability of the medical device 10 is improved.

Further, the expansion body 21 has a plurality of wire rod portions 50 that define the recesses 51 so that the recesses 51 have a plurality of recesses 51 arranged at least three at equal intervals in the circumferential direction of the expansion body 21. The plurality of recesses 51 each have a bottom portion 51a, a proximal end side upright portion 52, and a tip end side upright portion 53, and the plurality of electrode groups 22 may be arranged one by one in each of the plurality of recesses 51. As a result, the recesses 51 are arranged at equal intervals in the circumferential direction of the expansion body 21, so that when the tissue around the puncture hole Hh formed in the living body is cauterized, the shape can be made close to a regular polygon. , Can form a shunt of the size targeted by the surgeon.

Further, in the shunt forming method in the present embodiment, the tip including the expansion body 21 that can be expanded and contracted in the radial direction including the recess 51 recessed inward in the radial direction and the base end fixing portion 31 to which the base end of the expansion body 21 is fixed is included. A long shaft portion 20 having a portion 30, a plurality of electrode groups 22 provided along the expansion body 21 at intervals in the circumferential direction of the expansion body 21, and a current for supplying a current to the plurality of electrode groups 22. A method of forming a shunt in the atrial septal HA using a medical device 10 provided with a supply unit 101, wherein the dilated body 21 is radially inwardly recessed and can receive biological tissue when the dilated body 21 is expanded. It has a recess 51 that defines a reception space 51b, and each of the plurality of electrode groups 22 has a diameter from the base end of the bottom portion 51a located on the innermost side in the radial direction of the recess 51 so as to face the reception space 51b. The base end side electrode 61 arranged on the base end side upright portion 52 extending outward in the direction and the base end side electrode 61 at substantially the same position as the base end side electrode 61 in the circumferential direction of the expansion body 21 so as to face the receiving space 51b and the bottom portion 51a. It has a tip side electrode 62 arranged in a tip side upright portion 53 extending radially outward from the tip of the above, and a recess 51 is arranged in a puncture hole Hh formed in the atrial septum HA, and a receiving space 51b is provided. In each of the plurality of electrode groups 22, at least one of the proximal end side electrode 61 or the distal end side electrode 62 is brought into contact with the biological tissue of the atrial septal HA, and in the atrium. A current is supplied from the current supply unit 101 to the electrode in contact with the living tissue of the remote HA to cauterize the living tissue, and no current is supplied to the electrode not in contact with the living tissue during the cauterization. .. In the shunt forming method configured in this way, a thrombus is formed because the current is not supplied to the electrodes that are not in contact with the living tissue of each electrode group 22 but is supplied only to the electrodes that are in contact with the living tissue. It can be suppressed and effectively cauterized.

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. In the above-described embodiment, the wire rod portion 50 is provided with four in the circumferential direction and the electrode group 22 is also provided with four, but the wire rod portion 50 having the recess 51 and the electrode group 22 are provided with three or five or more. You may. In this case, the wire rod portions 50 are preferably arranged at equal intervals in the circumferential direction of the expansion body 21. Further, the wire rod portion 50 has a structure having a cantilever-shaped back support portion 56 between the two outer edge portions 55, but the structure of the wire rod portion 50 is not particularly limited, and the outer edge portion 55 and the back support portion 56 are not particularly limited. It may be a structure that does not have.

Further, as in the first modification shown in FIGS. 10 and 11, each of the proximal end side electrode 61 and the distal end side electrode 62 of the electrode group 22 can be independently supplied with a plurality of single electrodes. You may have 63. The determination unit 102 can determine whether or not each single electrode 63 is in contact with the contact target. The current supply unit 101 can independently supply a current to each single electrode 63. The single electrode 63 may be provided only on one of the proximal end side electrode 61 and the distal end side electrode 62. The determination unit 102 supplies a current to the single electrode 63a determined to be in contact with the living tissue, and supplies a current to the single electrode 63b determined to be in contact with or hardly in contact with the living tissue. The current supply unit 101 is controlled so as not to be used. As a result, the single electrode 63a that supplies an electric current for contacting the living tissue can be finely set, so that the surface area of the electrode that comes into contact with the living tissue can be easily increased, and the shape of the shunt formed by cauterization is effectively maintained. can. Further, since the single electrode 63b that does not supply an electric current because it does not come into contact with the living tissue can be finely set, it is possible to effectively suppress the formation of a thrombus due to the contact of the electrode through which the electric current flows with the blood.

Further, as in the second modification shown in FIG. 12, the expansion body 21 may have a structure in which a portion on the tip end side of the recess 51 is not provided. Although the adjacent wire rod portions 50 are not connected in the example of FIG. 11, they may be connected to each other.

Further, as in the third modification shown in FIG. 13, the expansion body 21 may be a balloon that can be expanded by supplying a fluid to the inside. The balloon is shaped to form a recess 51 when expanded.

Further, as in the fourth modification shown in FIG. 14, the expansion body 21 may be formed of a mesh in which a large number of thin wires are knitted. The mesh is shaped to form a recess 51 when expanded.

Further, as in the fifth modification shown in FIG. 15, the expansion body 21 may be formed by a link structure connected by a joint 57.

Further, as in the sixth modification shown in FIG. 16, the expansion body 21 may be formed in a mesh shape in which the wire rods are branched and merged. The expansion body 21 has a plurality of recesses 51, and the distal end side electrode 62 and the proximal end side electrode 61 are arranged in each recess 51. In each recess 51, the distal end side electrode 62 is arranged on the distal end side of the proximal end side electrode 61. That is, the plurality of proximal end side electrodes 61 arranged in the circumferential direction and the plurality of distal end side electrodes 62 arranged in the circumferential direction are not arranged alternately in the circumferential direction, but are arranged at substantially the same position in the circumferential direction. To. In the sixth modification, the traction shaft is not provided. Therefore, the expansion body 21 released from the storage sheath 25 expands the puncture hole Hh only by its own expansion force.

It should be noted that this application is based on Japanese Patent Application No. 2020-163591 filed on September 29, 2020, and the disclosure contents thereof are referred to and incorporated as a whole.

10 Medical device 20 Shaft part 21 Expansion body 22 Electrode group 30 Tip part 31 Base end fixing part 50 Wire rod part 51 Recessed part 51a Bottom part 51b Receiving space 52 Base end side standing part 53 Tip side standing part 61 Base end side electrode 62

Tip side electrode

63, 63a, 63b Single electrode 100 Energy supply device 101 Current supply unit 102 Judgment unit

Claims

An expansion body that can be expanded and contracted in the radial direction,
A long shaft portion having a tip portion including a proximal end fixing portion to which the proximal end of the extended body is fixed, and a long shaft portion.
A plurality of electrode groups provided along the expansion body and at intervals in the circumferential direction of the expansion body, and
A current supply unit that supplies a current to the plurality of electrode groups is provided.
The dilated body has a concave portion that is radially inward and defines a receiving space that can receive a living tissue when the dilated body is expanded.
The recess has a bottom portion located on the innermost side in the radial direction, a proximal end side erecting portion extending radially outward from the proximal end of the bottom portion, and a distal end side erecting portion extending radially outward from the tip end of the bottom portion.
The plurality of electrode groups are the base end side electrode arranged in the base end side upright portion so as to face the receiving space, and the circumferential direction of the extended body so as to face the receiving space. The tip side electrode is located at substantially the same position as the base end side electrode and is arranged in the tip end side upright portion.
The current supply unit is a medical device capable of independently supplying a current to the proximal end side electrode and the distal end side electrode.
The medical device according to claim 1, wherein at least one of the proximal end side electrode and the distal end side electrode has at least two single electrodes configured to supply current independently of the current supply unit.
The medical device according to claim 1 or 2, which has a determination unit for determining whether or not the electrode is in contact with the contact target.
The medical device according to claim 3, wherein the determination unit determines whether or not the electrode is in contact with the contact target based on the impedance detected by the electrode.
The expansion body has a plurality of wire rod portions that define the recesses so that the recesses have a plurality of recesses arranged at least three at equal intervals in the circumferential direction of the expansion body.
The plurality of recesses each have the bottom portion, the proximal end side upright portion, and the distal end side upright portion.
The medical device according to any one of claims 1 to 4, wherein the plurality of electrode groups are arranged one by one in each of the plurality of recesses.
An expansion body that can be expanded and contracted in the radial direction including a recess that is recessed inward in the radial direction, a long shaft portion that has a tip portion including a proximal end fixing portion to which the proximal end of the expansion body is fixed, and an expansion body. A shunt to the interatrial septum using a medical device provided with a plurality of electrode groups provided at intervals in the circumferential direction of the expansion body and a current supply unit for supplying a current to the plurality of electrode groups. Is a method of forming
The dilated body has a concave portion that is radially inward and defines a receiving space that can receive a living tissue when the dilated body is expanded.
Each of the plurality of electrode groups is arranged at a proximal end side erecting portion extending radially outward from the proximal end of the bottom portion located on the innermost side in the radial direction of the concave portion so as to face the receiving space. The side electrode is arranged so as to face the receiving space at a position substantially the same as the proximal end side electrode in the circumferential direction of the extended body and at the distal end side upright portion extending radially outward from the distal end of the bottom portion. With the tip side electrode,
The recess is placed in the puncture hole formed in the atrial septum to receive the biological tissue surrounding the puncture hole in the receiving space.
In each of the plurality of electrode groups, the proximal end side electrode or at least one of the distal end side electrodes is brought into contact with the biological tissue of the atrial septum, and the electrode is brought into contact with the biological tissue of the atrial septum. The living tissue is cauterized by supplying an electric current from the electric current supply unit.
A method in which an electric current is not supplied to an electrode that is not in contact with the living tissue during the cauterization.