Medical device

Abstract

Provided is a medical device that can reduce unevenness in the degree of burning caused by an energy transmission element and can suppress the occurrence of thrombus formation, tissue disorder, and the like caused by burning. A medical device (10) has a long shaft portion (20) and a dilator (21) provided at a distal end of the shaft portion (20) and capable of expanding and contracting in the radial direction, the dilator (21) having a plurality of wire portions (50) connected to the shaft portion (30) and a holding portion (51) formed by at least one of the wire portions (50) and holding a biological tissue, the holding portion (51) having a backrest portion (62) and an energy transmission element (22) that outputs energy, the backrest portion (62) having a support surface (63) capable of facing the energy transmission element (22) when the dilator (21) is dilated, the support surface (63) being capable of tilting in a manner substantially parallel to the energy transmission element (22) when the energy transmission element (22) moves toward the backrest portion (62).

Description

Technical Field

[0001] This invention relates to a medical device for energizing biological tissues. Background Technology

[0002] Chronic heart failure is a known type of heart disease. Based on cardiac function indicators, chronic heart failure is broadly classified into systolic insufficiency and diastolic insufficiency. Patients with diastolic insufficiency experience increased blood pressure in the left ventricle due to myocardial hypertrophy and increased stiffness, leading to decreased cardiac pumping function. Consequently, patients may exhibit symptoms of heart failure such as pulmonary edema. Additionally, there are heart diseases such as pulmonary hypertension that cause increased blood pressure in the right ventricle and decreased cardiac pumping function, resulting in symptoms of heart failure.

[0003] Shunt therapy has gained attention in recent years. In shunt therapy, for patients with heart failure, a shunt channel (through-hole) is formed in the ventricular septum as a buffer against rising ventricular pressure, which can alleviate symptoms of heart failure. Shunt therapy utilizes a transvenous access to the ventricular septum to form a through-hole of the desired size. As a medical device for performing such shunt therapy on the ventricular septum, there exists, for example, the device described in Patent Document 1.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: US Patent No. 8,882,697 Summary of the Invention

[0007] The problem that the invention aims to solve

[0008] The medical device in Patent Document 1 uses a balloon, which serves as a dilator and is located at the front end of the shaft, to enlarge the shunt channel orifice, and uses electrodes located on the balloon to maintain the shunt channel orifice. However, since the electrodes (energy transfer elements) of this medical device are exposed to the blood, there is a possibility that energy may be applied to the blood or unwanted areas, resulting in uneven burning, thrombosis, tissue damage, etc.

[0009] The present invention was proposed to solve the above-mentioned problems, and its purpose is to provide a medical device that can reduce the unevenness of the degree of burning caused by energy transfer elements and can inhibit the occurrence of thrombosis, tissue damage and other problems caused by burning.

[0010] Methods for solving problems

[0011] The medical device of the present invention, which achieves the above-mentioned objective, comprises: an elongated shaft portion; and a dilator disposed at the front end of the shaft portion, capable of radial expansion and contraction, the dilator having a plurality of wire portions connected to the shaft portion and at least one clamping portion formed by at least one of the wire portions, the clamping portion having a backrest and an energy transmission element for outputting energy, the backrest having a support surface that can be opposed to the energy transmission element when the dilator expands, and the support surface being capable of tilting substantially parallel to the energy transmission element when the energy transmission element moves toward the backrest.

[0012] Invention Effects

[0013] The medical device constructed in the above manner, because the support surface is approximately parallel to the energy transfer element in response to its movement, allows the energy transfer element to adhere closely to the biological tissue sandwiched between the energy transfer element and the support surface. Therefore, uneven burning caused by the energy transfer element can be reduced. Furthermore, it can prevent the energy transfer element from locally detaching from the biological tissue. Thus, it can prevent the energy transfer element from imparting energy to the bloodstream or unwanted areas, and can suppress the occurrence of thrombosis, tissue damage, etc., caused by burning.

[0014] Alternatively, at least one of the clamping portions may have two outer edges on both sides of the backrest in the width direction, wherein the width direction is orthogonal to the axial direction and radial direction of the relaxor. Thus, the outer edges effectively guide the energy transfer element moving from the backrest towards the backrest located between the outer edges. Therefore, the energy transfer element can press against the biological tissue supported by the two outer edges, pressing the biological tissue against the backrest positioned between the two outer edges. Consequently, the energy transfer element adheres closely to the biological tissue, is less likely to float away from the biological tissue, and its position relative to the biological tissue is stably maintained by the two outer edges.

[0015] The two outer edges can also be convex shapes facing outwards in the width direction. This ensures a wide area for arranging the backrest between the two outer edges. Furthermore, since the two outer edges in the width direction can support a wide range of biological tissue, it is easy to maintain the energy transfer elements and support surfaces of the biological tissue sandwiched between the two outer edges in an appropriate position.

[0016] The two outer edges can also be smoothly convex outwards in an arc shape in the width direction. Thus, the outer edges can be received without hooking onto the inner surface of a tubular component (e.g., a housing) that houses the expander in a retractable manner. Therefore, the outer edges can be smoothly received in the housing and smoothly released from the housing.

[0017] Alternatively, the maximum width in the width direction of the two outer edges sandwiching the backrest may be greater than the maximum width in the width direction of the energy transfer element. This makes it easier to induce the energy transfer element to compress towards the backrest from the outer edges.

[0018] Alternatively, under the action of an axial force from the energy transfer element, the backrest moves more than the two outer edges. Thus, the backrest allows the biological tissue pressed by the energy transfer element to recoil more gently and support it in the direction of compression of the energy transfer element compared to the outer edges. Therefore, the energy transfer element adheres closely to the biological tissue and is less likely to float away.

[0019] Alternatively, the expansion body may have an inwardly protruding portion between the energy transfer element and the backrest, and the maximum width in the width direction of the two outer edges sandwiching the backrest is greater than the maximum width in the width direction of the inwardly protruding portion. This allows for a structure that maintains the flexibility of the inwardly protruding portion while increasing the width of the two outer edges.

[0020] The backrest can also be a cantilever beam extending from the wire section. Therefore, the backrest can flex flexibly under stress.

[0021] The backrest can also be a component supported by at least one flexible support line, wherein the support line extends from the two outer edges that sandwich the backrest. Thus, the backrest can move more than the outer edges under axial force.

[0022] The backrest can also be at least one flexible backrest line extending from the two outer edges that sandwich the backrest. Thus, the backrest can flex more flexibly than the outer edges under axial force.

[0023] The backrest can also be a mesh-like component extending from the two outer edges that sandwich the backrest. Thus, the backrest can flex more flexibly than the outer edges under axial force.

[0024] The backrest can also be a membrane extending from the two outer edges that sandwich the backrest. Thus, the backrest can flex more flexibly than the outer edges under axial force. Attached Figure Description

[0025] Figure 1 This is a front view showing the overall configuration of the medical device according to the embodiment.

[0026] Figure 2 It is a magnified stereoscopic image of the vicinity of the diastolic body.

[0027] Figure 3 This is a front view showing a state where the wire section extends flat.

[0028] Figure 4 This is an explanatory diagram of a treatment method using the medical device of this embodiment. It schematically shows the state in which the diastolic body is placed in the through hole of the ventricular septum, wherein the medical device is a front view and the biological tissue is a cross-sectional view.

[0029] Figure 5 This is a schematic diagram illustrating the state of the front end of a medical device inserted into the ventricular septum. Part of the medical device is shown in the front view, while the housing and biological tissue are shown in cross-sectional views.

[0030] Figure 6 This is an illustrative diagram schematically showing the state in which the anterior portion of the diastolic body is expanded on the left ventricular side, wherein the medical device is the front view and the biological tissue is a sectional view.

[0031] Figure 7 This is an illustrative diagram schematically showing the placement of a diastolic body in the ventricular septum, with the medical device as the front view and the biological tissue as a sectional view.

[0032] Figure 8 This is an illustrative diagram schematically showing the state of diastolic body dilation in the ventricular septum, where the medical device is the front view and the biological tissue is a sectional view.

[0033] Figure 9 The images show cross-sectional views of the ventricular septum and diastolic body. (A) shows the state before the ventricular septum is clamped by the anterior side clamping part and the basal side clamping part. (B) shows the state in which the ventricular septum is clamped by the anterior side clamping part and the basal side clamping part.

[0034] Figure 10 This is a cross-sectional view showing the ventricular septum and diastolic body, (A) is along... Figure 9 (A) is a cross-sectional view along line AA, and (B) is a cross-sectional view along line AA. Figure 9 A sectional view of (B) along line BB.

[0035] Figure 11 This is an illustrative diagram schematically showing the state of the ventricular septum opening being dilated by a diastolic body, wherein the medical device is in front view and the biological tissue is in cross-sectional view.

[0036] Figure 12 This is a magnified three-dimensional view of the vicinity of the diastolic body of the medical device in the first modification example.

[0037] Figure 13 The following is an enlarged perspective view of the area near the front-side clamping part of the modified medical device. (A) shows the second modified example, (B) shows the third modified example, (C) shows the fourth modified example, and (D) shows the fifth modified example. Detailed Implementation

[0038] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. It should be noted that, for ease of explanation, the dimensions in the drawings may be exaggerated and differ from the actual dimensions. In addition, in this specification, the side of the medical device 10 that is inserted into the cavity of the biological body is referred to as the "front end side," and the operating side is referred to as the "base end side."

[0039] like Figure 4 As shown, the medical device 10 of this embodiment is configured to cause the through-hole Hh formed in the ventricular septum HA of the patient's heart H to dilate, and to perform a maintenance treatment to maintain the further dilated through-hole Hh at its size.

[0040] like Figure 1 As shown, the medical device 10 of this embodiment has an elongated shaft portion 20, a dilator 21 disposed at the front end of the shaft portion 20, and an operating portion 23 disposed at the base end of the shaft portion 20. The dilator 21 is provided with an energy transfer element 22 for performing the aforementioned maintenance treatment.

[0041] The shaft portion 20 has an outer shaft 31 that holds the diaphragm 21 at its front end and a housing 30 that houses the outer shaft 31. The housing 30 is axially movable relative to the outer shaft 31. The housing 30 can house the diaphragm 21 inside when it is moved to the front end side of the shaft portion 20. By moving the housing 30 from the state in which the diaphragm 21 is housed toward the base end side, the diaphragm 21 can be exposed.

[0042] The traction shaft 33 is housed inside the outer shaft 31. The traction shaft 33 protrudes from the front end of the outer shaft 31 towards the front end side, and its front end is fixed to the front end member 35. The base end of the traction shaft 33 extends from the operating part 23 towards the base end side. The front end member 35, which is used to fix the front end of the traction shaft 33, may not be fixed to the relaxor body 21. Thus, the front end member 35 can pull the relaxor body 21 in the compression direction. In addition, when the relaxor body 21 is housed in the housing 30, by moving the front end member 35 away from the relaxor body 21 towards the front end side, it becomes easier for the relaxor body 21 to move in the extension direction, thereby improving the housekeeping performance.

[0043] The operating unit 23 includes a frame 40 for the surgeon to hold, an operating disc 41 that the surgeon can rotate, and a conversion mechanism 42 that is linked to the rotation of the operating disc 41. A traction shaft 33 is held within the conversion mechanism 42 inside the operating unit 23. The conversion mechanism 42 is capable of moving the held traction shaft 33 axially forward and backward in conjunction with the rotation of the operating disc 41. For example, a rack and pinion mechanism can be used as the conversion mechanism 42.

[0044] A more detailed explanation of the diastolic body 21. (e.g.) Figure 2 and Figure 3As shown, the dilator 21 has a plurality of wire portions 50 in the circumferential direction. In this embodiment, four wire portions 50 are provided in the circumferential direction. It should be noted that the number of wire portions 50 is not particularly limited. The wire portions 50 are capable of expanding and contracting radially in the dilator 21. In the natural state without external force, it becomes the reference shape in which the dilator 21 expands radially. The base end of the wire portion 50 extends from the front end of the outer shaft 31 toward the front end side. The front end of the wire portion 50 extends from the base end of the front end member 35 toward the base end side. The wire portions 50 are inclined radially increasing from both ends of the dilator 21 toward the center. In addition, the wire portion 50 has a clamping portion 51 that is concave in the radial direction of the dilator 21 at the axial center.

[0045] The clamping portion 51 has a base-side clamping portion 52 and a front-side clamping portion 53. The clamping portion 51 also has a base-side outward protrusion 55, an inward protrusion 56, and a front-side outward protrusion 57. In the standard configuration, regarding the distance between the base-side clamping portion 52 and the front-side clamping portion 53, it is preferable that the distance is slightly larger in the axial direction on the radially outer side than on the inner side. This allows for easy placement of biological tissue between the base-side clamping portion 52 and the front-side clamping portion 53 from the radially outer side.

[0046] The base-end side protrusion 55 is located on the base end side of the base end side clamping portion 52 and is formed into a shape that bulges outward toward the radial direction.

[0047] The inner protrusion 56 is located between the base-side clamping portion 52 and the front-side clamping portion 53, and is formed into a radially convex shape. The inner protrusion 56 has a central through hole 59 for easy bending.

[0048] The front-side outward protrusion 57 is located on the front-side of the front-side clamping portion 53 and is formed into a shape that bulges outward in a radial direction. A front-side through hole 60 is formed in the wire portion 50 near the front-side outward protrusion 57 and the front-side clamping portion 53. The front-side through hole 60 penetrates radially toward the stretcher body 21. This reduces the bending rigidity of the front-side outward protrusion 57. Therefore, the front-side outward protrusion 57 can easily deform into a convex shape that bulges outward in a radial direction, or it can easily deform into a flattened convex shape. It should be noted that the number of front-side through holes 60 is not particularly limited. Therefore, the number of front-side through holes 60 can be two or more.

[0049] The base-side clamping portion 52 has a protrusion 54 protruding toward the front end side. An energy transfer element 22 is disposed on the protrusion 54.

[0050] The front-end clamping portion 53 has two outer edges 61 disposed on both outer sides in the width direction and a backrest 62 disposed between the two outer edges 61. The width direction is a direction orthogonal to the axial direction and radial direction of the relaxer body 21. When the relaxer body 21 relaxes, the backrest 62 has a support surface 63 that can face the energy transmission element 22 disposed on the front-end clamping portion 53.

[0051] Each outer edge 61 has an arcuate shape that bulges outward in the width direction. Therefore, a wide area for accommodating the backrest 62 and the front through-hole 60 can be ensured between the two outer edges 61. Furthermore, since the outer edges 61 become smooth in the width direction, it is possible to prevent the outer edges 61 from hooking onto the inner surface of the housing 30 that houses the expansion body 21. The maximum width L1 of the outer edge 61 in the width direction is larger than the maximum width L2 of the inner protrusion 56 in the width direction. Therefore, a shape can be formed that maintains the flexibility of the inner protrusion 56 while widening the outer edge 61 in the width direction. Additionally, the maximum width L5 of the support surface 63 in the width direction is not particularly limited, but it is preferably the same as or slightly larger than the maximum width L3 of the energy transfer element 22 in the width direction. Thus, the support surface 63 can appropriately support the biological tissue compressed by the energy transfer element 22. Furthermore, the maximum width L1 of the outer edge 61 in the width direction is not particularly limited, but it is preferably larger than the maximum width L3 of the energy transfer element 22 in the width direction. Similarly, the maximum width L4 of the front end through hole 60 in the width direction is not particularly limited, but it is preferably larger than the maximum width L3 of the energy transfer element 22 in the width direction.

[0052] The backrest 62 protrudes from the inwardly protruding portion 56 of the front-side clamping portion 53 toward the outwardly protruding portion 57 of the front-side between the two outer edges 61. The backrest 62 is spaced apart from the two outer edges 61. The end of the backrest 62 on the front-side outwardly protruding portion 57 side is a free end. Therefore, since the backrest 62 is cantilevered to fix the base end, it is easy to bend. Therefore, under the force exerted on the support surface 63 toward the front-side, the backrest 62 can bend more easily than each of the outer edges 61. The backrest 62 is configured to be clamped between the two outer edges 61, but not necessarily strictly within the space between the two outer edges 61. The backrest 62 may also be configured to be clamped between the two outer edges 61 at a position slightly offset from the space between the two outer edges 61. It should be noted that it is preferable that at least a portion of the backrest 62 is disposed within the space between the two outer edges 61.

[0053] The backrest 62 has a through hole 64 formed on the base side, that is, the side near the inner protrusion 56. The through hole 64 extends radially (in the thickness direction of the wire portion 50) through the stretcher body 21. As a result, the bending stiffness of the backrest 62 near the inner protrusion 56 is low. Therefore, the backrest 62 can easily flex under the force borne by the support surface 63. It should be noted that the number of through holes 64 is not particularly limited. Therefore, the number of through holes 64 can be two or more. Alternatively, the backrest 62 may not have a through hole 64.

[0054] In this embodiment, the energy transfer element 22 is disposed on the base-side clamping part 52 and the backrest 62 is disposed on the front-side clamping part 53. However, the energy transfer element 22 can also be disposed on the front-side clamping part 53 and the backrest 62 can be disposed on the base-side clamping part 52.

[0055] The wire portion 50 forming the relaxor 21 has, for example, a flat plate shape cut from a cylinder. The wire forming the relaxor 21 can be configured with a thickness of 50 to 500 μm and a width of 0.3 to 2.0 mm. It should be noted that the wire forming the relaxor 21 can also have dimensions outside of these ranges. Furthermore, the shape of the wire portion 50 is not limited and can be, for example, a circular cross-sectional shape or other cross-sectional shapes.

[0056] Since the energy transfer element 22 is located on the protrusion 54 of the base-side clamping portion 52, when the clamping portion 51 clamps the ventricular septum HA, energy from the energy transfer element 22 is transferred from the right ventricular side to the ventricular septum HA. It should be noted that when the energy transfer element 22 is located on the front-side clamping portion 53, energy from the energy transfer element 22 is transferred from the left ventricular side to the ventricular septum HA.

[0057] The energy transfer element 22 is, for example, composed of bipolar electrodes that receive electrical energy from an external energy supply device (not shown). In this case, energization is achieved between the energy transfer elements 22 disposed in each wire section 50. The energy transfer element 22 is connected to the energy supply device via a conductor (not shown) covered with an insulating coating material. The conductor is led to the outside via a shaft section 20 and an operating section 23 and connected to the energy supply device.

[0058] The energy transfer element 22 can also be configured as a unipolar electrode. In this case, energization is achieved between the counter electrode plates prepared externally. Alternatively, the energy transfer element 22 can also be a heating element (electrode chip) that receives high-frequency electrical energy from an energy supply device and generates heat. In this case, energization is achieved between the energy transfer elements 22 disposed in each wire section 50. Furthermore, the energy transfer element 22 can be configured with elements capable of imparting energy to the through hole Hh, such as structures that exert heating or cooling effects through microwave energy, ultrasonic energy, coherent light such as lasers, heated fluids, cooled fluids, or chemical media, structures that generate friction, heaters equipped with wires, etc., and there is no particular limitation on the specific configuration.

[0059] The wire section 50 can be formed of a metallic material. Examples of suitable metallic materials include titanium-based alloys (Ti-Ni, Ti-Pd, Ti-Nb-Sn, etc.), copper-based alloys, stainless steel, β-titanium steel, and Co-Cr alloys. It should be noted that alloys with elasticity, such as nickel-titanium alloys, are preferred. However, the material of the wire section 50 is not limited to these, and it can be formed of other materials.

[0060] The shaft portion 20 has an inner shaft 32 inside the outer shaft 31, and a traction shaft 33 is housed inside the inner shaft 32. A guide wire cavity is formed along the axial direction in the traction shaft 33 and the front end component 35, which allows the guide wire 11 to be inserted.

[0061] Preferably, the housing 30, outer shaft 31, and inner shaft 32 of the shaft portion 20 are formed of a material with a certain degree of flexibility. Examples of such materials include polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomers, or mixtures of two or more of the above, polyolefins, soft polyvinyl chloride resin, polyamide, polyamide elastomer, polyester, polyester elastomer, polyurethane, polytetrafluoroethylene and other fluororesins, polyimide, PEEK, silicone rubber, latex rubber, etc.

[0062] The traction shaft 33 can be formed from a long wire, such as a nickel-titanium alloy, a copper-zinc alloy, or other highly elastic alloys, a metal material such as stainless steel, or a resin material with high rigidity. Alternatively, it can be formed from a material coated with resin materials such as polyvinyl chloride, polyethylene, polypropylene, ethylene-propylene copolymer, or fluoropolymer.

[0063] The front-end component 35 can be formed from materials such as nickel-titanium alloys, copper-zinc alloys, stainless steel, or resin materials with high rigidity.

[0064] Next, a treatment method using the medical device 10 of this embodiment will be described. This treatment method is for patients suffering from heart failure (left ventricular failure). More specifically, as follows... Figure 4The image shows a treatment method for patients with chronic heart failure who have increased left ventricular myocardial hypertrophy and stiffness, and elevated blood pressure in the left ventricular HLa.

[0065] During the formation of the perforation Hh, the surgeon delivers a guide device, consisting of a guide sheath and a dilator, to the vicinity of the ventricular septum HA. The guide device can be delivered, for example, via the inferior vena cava IV to the right ventricle HRa. Alternatively, guide device delivery can be performed using guidewire 11. The surgeon can insert guidewire 11 through the dilator and deliver the guide device along guidewire 11. It should be noted that guide device insertion and guidewire 11 insertion relative to a living organism can be performed using known methods such as vascularized guide devices.

[0066] Next, the surgeon inserts a puncture device (not shown) and a dilator from the right ventricular HRa side toward the left ventricular HLa side to form a through-hole Hh. For example, a device such as a steel wire with a sharp tip can be used as the puncture device. The puncture device allows the dilator to be inserted and delivered to the ventricular septum HA. The puncture device can be delivered to the ventricular septum HA after the guidewire 11 has been removed from the dilator, replacing the guidewire 11.

[0067] Next, as Figure 4 As shown, the surgeon pre-guides the medical device 10 to the vicinity of the ventricular septum HA along a guidewire 11 inserted from the right ventricle HRa through a tracing hole Hh into the left ventricle HLa. Furthermore, as... Figure 5 As shown, a portion of the front end of the medical device 10 passes through a through-hole Hh in the ventricular septum HA to reach the left ventricle HLa. When the medical device 10 is inserted, the diastolic body 21 is in a contracted state housed in the housing 30. In the contracted state, the diastolic body 21 contracts radially by deforming the naturally convex base-side outward protrusion 55, inward protrusion 56, and front-side outward protrusion 57 into a nearly flat shape.

[0068] Next, as Figure 6 As shown, by moving the housing 30 towards the base, the anterior portion of the diastolic body 21 is exposed within the left ventricular HLa. Consequently, the anterior portion of the diastolic body 21 expands radially within the left ventricular HLa under its own restorative force. Next, as... Figure 7As shown, by moving the housing 30 towards the base end, the entire diastolic body 21 is exposed. Consequently, the base end portion of the diastolic body 21 expands radially within the right ventricle HRa under its own restorative force. At this time, the inner protrusion 56 is positioned inside the through-hole Hh. Thus, the entire diastolic body 21 expands under its own restorative force, restoring to its original or near-reference shape. At this time, the ventricular septum HA is positioned between the base end clamping portion 52 and the front end clamping portion 53. In the biological tissue clamping direction, the ventricular septum HA is positioned between the energy transfer element 22 and the backrest 62. It should be noted that the diastolic body 21 may not completely return to its reference shape or may return to a shape close to the reference shape due to contact with the through-hole Hh. Moreover, in this state, the diastolic body 21 is not covered by the housing 30 and is not subjected to force from the traction shaft 33. This shape of the diastolic body 21 is also included in the reference shape.

[0069] Each outer edge 61 has an arc shape that bulges outward in the width direction. Therefore, the outer edge 61 is less likely to snag on the inner surface of the housing 30. Thus, the expander 21 with the outer edge 61 can be smoothly released from the housing 30.

[0070] Next, the surgeon operates the operating unit 23 while the ventricular septum HA is held in place by the clamping part 51, moving the traction shaft 33 towards the base. Thus, as... Figure 8 As shown, the diastolic body 21, which is subjected to axial compressive force, is in a diastolic mode that expands radially compared to the reference configuration. Because the diastolic body 21 is in a diastolic mode, the basal-side clamping portion 52 and the anterior-side clamping portion 53 approach each other, clamping the ventricular septum HA between them. At this time, the energy transfer element 22 is opposite to the backrest 62. The clamping portion 51 further expands while clamping the ventricular septum HA, pushing the through-hole Hh radially open.

[0071] like Figure 9 (A) and Figure 10 As shown in (A), when the base-side clamping portion 52 and the front-side clamping portion 53 approach each other from their separated state, as Figure 9 (B) and Figure 10As shown in (B), the ventricular septum HA is clamped between the basal clamping portion 52 and the anterior clamping portion 53. Furthermore, the energy transfer element 22 presses the ventricular septum HA towards the anterior side. At this time, the anterior clamping portion 53 flexes the backrest 62 towards the anterior side between the two outer edges 61, accommodating the ventricular septum HA pressed by the energy transfer element 22 between the two outer edges 61. The support surface 63 of the backrest 62 receives force from the energy transfer element 22 via the ventricular septum HA, flexing in a manner approximately parallel to the energy transfer element 22. Simultaneously, while the backrest 62 flexes gently, a reaction force in the opposite direction to the pushing direction of the energy transfer element 22 acts on the ventricular septum HA pressed by the energy transfer element 22. Thus, the energy transfer element 22 adheres tightly to the ventricular septum HA. Furthermore, it can prevent the energy transfer element 22 from partially floating away from the ventricular septum HA.

[0072] Furthermore, when the energy transfer element 22 comes into contact with the ventricular septum HA, the two outer edges 61 clamping the backrest 62 effectively induce the energy transfer element 22 towards the backrest 62 located between the outer edges 61. Thus, the energy transfer element 22 can be pressed while in contact with the ventricular septum HA supported by the two outer edges 61, pressing the ventricular septum HA against the backrest 62 positioned between the two outer edges 61. Therefore, the energy transfer element 22 adheres tightly to the ventricular septum HA, making it difficult to float away from the ventricular septum HA, and the position of the energy transfer element 22 relative to the ventricular septum HA is stably maintained between the two outer edges 61.

[0073] The ventricular septum HA is clamped between the energy transfer element 22 and the backrest 62 by the concave-convex structure of the protrusion 54 and the anterior through-hole 60. At this time, due to the deflection of the backrest 62, the ventricular septum HA is easily clamped by the concave-convex structure of the protrusion 54 and the anterior through-hole 60. Thus, the basal clamping portion 52 and the anterior clamping portion 53 support each other circumferentially in the diastolic body 21, thereby suppressing circumferential displacement of the diastolic body 21 between them. Therefore, the diastolic tension of the diastolic body 21 can be reliably transmitted to the biological tissue. The basal clamping portion 52 and the anterior clamping portion 53 clamp the biological tissue during the relaxation of the diastolic body 21. The relaxation of the diastolic body 21 refers to any moment during the relaxation of the diastolic body 21, the instant of complete relaxation of the diastolic body 21, or from the moment of complete relaxation until contraction.

[0074] Furthermore, the maximum width L1 of the outer edge portion 61 in the width direction is greater than the maximum width L2 of the inner protrusion 56 in the width direction. Therefore, the inner protrusion 56 can be easily and flexibly maintained, and the area of ​​the backrest 62 can be easily secured between the two outer edges 61. In addition, the maximum width L1 of the outer edge portion 61 in the width direction is greater than the maximum width L3 of the energy transfer element 22 in the width direction. Therefore, the outer edge portion 61 can easily induce the compression direction of the energy transfer element 22 towards the backrest 62. In addition, the maximum width L4 of the front end through hole 60 in the width direction is greater than the maximum width L3 of the energy transfer element 22 in the width direction. Therefore, the outer edge portion 61 can easily induce the compression direction of the energy transfer element 22 towards the backrest 62. Furthermore, since the energy transfer element 22 can easily enter between the outer edges 61, the force of mutual support between the base end side clamping portion 52 having the energy transfer element 22 and the front end side clamping portion 53 having the outer edge portion 61 in the circumferential direction of the relaxor 21 can be easily applied.

[0075] After the patency test Hh is relaxed, the dynamics of blood circulation are confirmed. For example... Figure 11 As shown, the surgeon delivers the blood circulation dynamic monitoring device 100 to the right ventricle HRa via the inferior vena cava IV. The blood circulation dynamic monitoring device 100 can be, for example, a known echo catheter. The surgeon can display the echo image acquired by the blood circulation dynamic monitoring device 100 on a display device such as a monitor, and can confirm the amount of blood passing through the through-hole Hh based on the display results.

[0076] Next, the surgeon performs a maintenance procedure to maintain the size of the through-hole Hh. During this maintenance procedure, energy is applied to the edge of the through-hole Hh via the energy transfer element 22, thereby cauterizing (heating) the edge of the through-hole Hh. If the biological tissue near the edge of the through-hole Hh is cauterized via the energy transfer element 22, a modified portion of the biological tissue is formed near the edge. Because the modified biological tissue becomes inelastic, the through-hole Hh can maintain its shape as it was when pushed open by the dilator 21.

[0077] Because the medical device 10 has a backrest 62, the energy transfer element 22 is in close contact with the ventricular septum HA. Therefore, uneven burning caused by the energy transfer element 22 can be reduced. In addition, the energy transfer element 22 can be prevented from floating away from the ventricular septum HA. Therefore, the energy transfer element 22 can be prevented from supplying energy to unwanted areas in the blood, thus inhibiting the occurrence of thrombosis, tissue damage, etc.

[0078] Furthermore, the energy transfer element 22 is disposed on the protrusion 54 of the base-side clamping portion 52. Therefore, by pressing the protrusion 54 against the ventricular septum HA, the energy transfer element 22 is maintained while submerged in the biological tissue. As a result, the energy transfer element 22 can be prevented from transferring energy to the blood or unwanted sites, thus inhibiting the occurrence of thrombosis, tissue damage, etc.

[0079] After maintaining the procedure, the blood circulation dynamics are reconfirmed. Once the blood volume through the through-hole Hh is at the desired level, the surgeon reduces the diameter of the dilator 21 and retracts it into the housing 30 before removing it from the through-hole Hh. Because the outer edge 61 is an arc-shaped protrusion bulging outwards in the width direction, it is less likely to snag on the inner surface of the housing 30. Therefore, the dilator 21 with the outer edge 61 is smoothly retracted into the housing 30. The surgeon then removes the entire medical device 10 from the body, ending the procedure.

[0080] As described above, the medical device 10 of the above embodiment has an elongated shaft portion 20 and a dilator 21 disposed at the front end of the shaft portion 20 and capable of radial expansion and contraction. The dilator 21 has a plurality of wire portions 50 connected to the shaft portion 30 and at least one clamping portion 51 formed by at least one wire portion 50. The clamping portion 51 has a backrest 62 and an energy transfer element 22 for outputting energy. The backrest 62 has a support surface 63 that can face the energy transfer element 22 when the dilator 21 expands. When the energy transfer element 22 moves toward the backrest 62, the support surface 63 can be tilted in a manner substantially parallel to the energy transfer element 22. Thus, the medical device 10 moves in response to the movement of the energy transfer element 22, making the support surface 63 substantially parallel to the energy transfer element 22, thereby allowing the energy transfer element 22 to adhere tightly to the biological tissue between the energy transfer element 22 and the support surface 63. Therefore, unevenness in the degree of burning caused by the energy transfer element 22 can be reduced. Furthermore, it can suppress the energy transfer element 22 from surfacing locally from biological tissue. Therefore, it can suppress the energy transfer element 22 from transferring energy into the blood or to unwanted sites, and can suppress the occurrence of thrombosis, tissue damage, etc., caused by burning. In this embodiment, the backrest 62 tilts by flexing under axial force. It should be noted that the backrest 62, for example, is a second modification described later (see...). Figure 13 As shown in (A), it can also tilt without bending by being supported on other deformable components.

[0081] Furthermore, at least one clamping portion 51 has two outer edges 61 on both sides of the backrest 62 in a direction orthogonal to the axial direction of the relaxer 21 and in a direction orthogonal to the radial direction of the relaxer 21, i.e., the width direction. Thus, the outer edges 61 effectively guide the energy transfer element 22, which moves towards the backrest 62, toward the backrest 62 located between the outer edges 61. Therefore, the energy transfer element 22 can press against the biological tissue supported by the two outer edges 61, and can press the biological tissue toward the backrest 62 disposed between the two outer edges 61. Therefore, the energy transfer element 22 is tightly attached to the biological tissue, is not easily lifted off the biological tissue, and its position relative to the biological tissue can be stably maintained by the two outer edges 61.

[0082] Furthermore, the two outer edges 61 are convex in shape facing outwards in the width direction. This ensures a wide area for arranging the backrest 62 between the two outer edges 61. Additionally, since the two outer edges 61 in the width direction can support a wide range of biological tissue, it is easy to maintain the energy transfer element 22 of the biological tissue and the support surface 63 sandwiched between the two outer edges 61 in an appropriate position.

[0083] Furthermore, the two outer edges 61 are smoothly convex outwards in an arc shape in the width direction. Thus, the outer edges 61 can be received without snagging on the inner surface of, for example, a housing 30 that houses the expander 21 in a retractable manner. Therefore, the outer edges 61 can be smoothly received in the housing 30 and smoothly released from the housing 30.

[0084] Furthermore, the maximum width L1 of the two outer edges 61 sandwiching the backrest 62 in the width direction is greater than the maximum width L3 of the energy transfer element 22 in the width direction. As a result, the outer edges 61 can be used to induce the compression direction of the energy transfer element 22 towards the backrest 62.

[0085] Furthermore, under the axial force exerted on the energy transfer element 22, the backrest 62 moves more than the two outer edges 61. Therefore, the backrest 62 can more readily and gently support the biological tissue pressed by the energy transfer element 22 in the direction of compression compared to the outer edges 61. Consequently, the energy transfer element 22 adheres tightly to the biological tissue and is less likely to float away from it.

[0086] Furthermore, the expansion body 21 has a radially inwardly bulging inner portion 56 between the energy transfer element 22 and the backrest 62, and the maximum width L1 of the two outer edges 61 sandwiching the backrest 62 in the width direction is larger than the maximum width L2 of the inner bulge 56 in the width direction. Thus, a structure can be formed that widens the width of the two outer edges 61 while maintaining the flexibility of the inner bulge 56. Because the inner bulge 56 is flexible, the expansion body 21 can be housed, for example, in a housing 30. Furthermore, because the inner bulge 56 is flexible, it is easy to bring the energy transfer element 22 sandwiching the inner bulge 56 closer to or separate it from the backrest 62.

[0087] Furthermore, the backrest 62 is a cantilever beam extending from the wire section 50. As a result, the backrest 62 can flex flexibly under stress.

[0088] In addition, the present invention also provides a treatment method. This treatment method is a burning method for cauterizing biological tissue. The cauterization device has an elongated shaft portion 20 and a dilator 21 disposed at the front end of the shaft portion 20 and capable of radial expansion and contraction. The dilator 21 has a plurality of wire portions 50 connected to the shaft portion 20 and at least one clamping portion 51 formed by at least one of the wire portions 50. The clamping portion 51 has a backrest 62 and an energy transfer element 22 for outputting energy. The backrest 62 inserts the cauterization device, having a support surface 63 that can face the energy transfer element 22 when the dilator 21 expands, into the right ventricle. The front end of the dilator 21, which contracts radially through a through-hole Hh opened in the ventricular septum HA, is inserted into the left ventricle. The contracted front end of the dilator 21 expands within the left ventricle under its own restoring force, and the contracted base end of the dilator 21 is also subjected to its own restoring force. Under the action of the energy transfer element 22, the bio-tissue near the edge of the through-hole Hh of the ventricular septum HA is positioned between the energy transfer element 22 and the backrest 62. By causing the expanded diastolic body 21 to expand radially, the bio-tissue is clamped by the clamping part 51 and the through-hole Hh is pushed open. Accompanying the expansion of the through-hole Hh, the energy transfer element 22 presses the bio-tissue toward the backrest 62. By causing the support surface 63 of the backrest 62 to flex in a manner approximately parallel to the energy transfer element 22, the reaction force from the support surface 63 of the backrest 62 acts on the bio-tissue, thereby causing the energy transfer element 22 to adhere tightly to the bio-tissue. The energy output from the energy transfer element 22, which is in close contact with the bio-tissue, is used to burn the bio-tissue.

[0089] In the cauterization method constructed as described above, since the support surface 63 is approximately parallel to the energy transfer element 22 in response to its movement, the energy transfer element 22 can be made to adhere tightly to the biological tissue between the energy transfer element 22 and the support surface 63. Therefore, uneven cauterization caused by the energy transfer element 22 can be reduced. Furthermore, the lifting of the energy transfer element 22 from the biological tissue can be prevented. Therefore, the energy transfer element 22 can be prevented from imparting energy to the blood or unwanted areas, and the occurrence of thrombosis, tissue damage, etc., caused by cauterization can be suppressed.

[0090] It should be noted that the present invention is not limited to the above-described embodiments, and those skilled in the art can make various modifications within the scope of the technical concept of the present invention. For example, such as Figure 12 As shown in the first modified example, the outer edge 61 may also be formed as a convex shape without facing outward in the width direction.

[0091] Furthermore, there are no restrictions on the way the backrest is positioned. For example, as shown in Figure 62. Figure 13 As shown in the second variation of (A), the backrest 62 is not cantilevered; it can be supported by at least one (preferably multiple) flexible support line 65 extending from the two outer edges 61. The support line 65 is thinner and more flexible than the outer edges 61. The material of the support line 65 is not particularly limited, as long as it can be flexibly deformable. For example, suitable materials include superelastic alloys such as nickel-titanium alloys and copper-zinc alloys, metals such as stainless steel, polyolefins such as polyethylene, polypropylene, polybutene, ethylene-propylene copolymers, ethylene-vinyl acetate copolymers, ionomers, or mixtures thereof, soft polyvinyl chloride resins, polyamides, polyamide elastomers, polyesters, polyester elastomers, polyurethanes, polytetrafluoroethylene, fluoropolymers such as polyimide, PEEK, silicone rubber, latex rubber, etc. The backrest 62 is connected to the outer edges 61 only by the support line 65. Therefore, the backrest 62 is more prone to tilting compared to the outer edges 61 when subjected to axial forces. The support lines 65 may also be multiple and generally parallel. Alternatively, the support lines 65 may be multiple and arranged in a mesh pattern.

[0092] In addition, such as Figure 13 As shown in the third variation of (B), the backrest 62 can also be formed by at least one (preferably multiple) backrest thread 66 fixed at both ends to the outer edge 61. The material of the backrest thread 66 is not particularly limited, as long as it can be flexibly deformed; for example, a material suitable for the support thread 65 described above can be used. The support surface 63 of the backrest 62 is formed by multiple backrest threads 66 with gaps between them.

[0093] In addition, such as Figure 13As shown in the fourth variation of (C), the backrest 62 can also be a mesh component disposed between the two outer edges 61. The mesh component can be constructed, for example, from multiple fine wires or by forming a large number of holes in a flexible component. The material of the mesh component is not particularly limited, as long as it can be flexibly deformable; for example, the material used for the support wire 65 described above can be appropriately used.

[0094] In addition, such as Figure 13 As shown in the fifth modified example (D), the backrest 62 can also be an elastically deformable membrane disposed between the two outer edges 61. The membrane can be made of materials such as fluoropolymers, polyethylene, polypropylene, thermoplastic elastomers, rubber, etc.

[0095] It should be noted that this application is based on Japanese Patent Application No. 2019-178331, filed on September 30, 2019, the disclosure of which is incorporated herein by reference in its entirety.

[0096] Explanation of reference numerals in the attached figures

[0097] 10 Medical Equipment

[0098] 20 Shaft section

[0099] 21. Diastolic body

[0100] 22 Elements of Energy Transfer

[0101] 30 Shaft section

[0102] 50 Wire Department

[0103] 51 Clamping Part

[0104] 52 Base end side clamping part

[0105] 53 Front-end side clamping part

[0106] 54 convex part

[0107] 56 inner convex part

[0108] 60 Front-end side through hole

[0109] 61 Outer edge

[0110] 62 Backrest

[0111] 63 Support surface

[0112] 65 Support line

[0113] 66. Backrest thread

[0114] Maximum width of L1 outer edge

[0115] Maximum width of L2 inner convex part

[0116] Maximum width of L3 energy transfer element

Claims

1. A medical device, characterized in that, include: Long shaft portion; as well as A dilator, located at the front end of the shaft, is capable of expanding and contracting radially. The dilator has a plurality of wire portions connected to the shaft portion and at least one clamping portion formed by at least one of the wire portions. The clamping part has an energy transfer element that supports the back and outputs energy. The backrest has a support surface that can face the energy transfer element when the expansion body expands. As the energy transfer element moves toward the backrest, the support surface can tilt in a manner substantially parallel to the energy transfer element. At least one of the clamping portions has two outer edges on both sides of the backrest in the width direction, wherein the width direction is orthogonal to the axial direction and the radial direction of the relaxer body. The backrest is at least one flexible backrest line extending from the two outer edges that sandwich the backrest.

2. The medical device according to claim 1, characterized in that, The two outer edges are convex shapes facing outward in the width direction.

3. The medical device according to claim 2, characterized in that, The two outer edges are smoothly convex outward in the width direction in an arc shape.

4. The medical device according to any one of claims 1 to 3, characterized in that, The maximum width in the width direction of the two outer edges sandwiching the backrest is greater than the maximum width in the width direction of the energy transfer element.

5. The medical device according to any one of claims 1 to 3, characterized in that, Under the action of the axial force from the energy transfer element, the backrest moves more than the two outer edges.

6. The medical device according to any one of claims 1 to 3, characterized in that, The expansion body has a radially convex inwardly bulging portion between the energy transfer element and the backrest. The maximum width in the width direction of the two outer edges that are sandwiched between the backrests is greater than the maximum width in the width direction of the inner protrusion.

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