US-12616516-B2 - Medical device

Abstract

A medical device includes an expansion body, an elongated shaft portion, and a plurality of electrode assemblies. The expansion body includes a recessed portion that is recessed radially inward. The recessed portion includes a radially innermost bottom portion including a proximal side curved portion and a distal side curved portion, a proximal side upright portion, and a distal side upright portion. Each of the plurality of electrode assemblies includes an electrode portion disposed along the expansion body from the proximal side upright portion or the distal side upright portion to the bottom portion so as to face a receiving space defined by the recessed portion. The proximal side curved portion and the distal side curved portion deform in response to expansion and contraction of the expansion body. The electrode portion is in a floating state with respect to the distal side curved portion and the proximal side curved portion.

Inventors

• Yusuke Takahashi

Assignees

• TERUMO KABUSHIKI KAISHA

Dates

Publication Date

20260505

Application Date

20230224

Priority Date

20200826

Claims (20)

1. 1 . A medical device comprising: an expansion body configured to expand and contract in a radial direction; an elongated shaft including a distal portion that includes a proximal end fixing portion to which a proximal end of the expansion body is fixed; a plurality of electrode assemblies extending from the proximal end fixing portion of the shaft along at least a part of the expansion body; the expansion body includes a recessed portion that is recessed radially inward relative to portions of the expansion body proximal and distal of the recessed portion and that defines a receiving space to receive biological tissue when the expansion body is expanded while positioned in a hole in the biological tissue; the recessed portion of the expansion body including a radially innermost bottom portion including a proximal side curved portion and a distal side curved portion, a proximal side upright portion extending radially outward from the proximal side curved portion, and a distal side upright portion extending radially outward from the distal side curved portion, the proximal side curved portion being proximal of the distal side curved portion; each of the plurality of electrode assemblies including an electrode portion disposed along the expansion body from the proximal side upright portion to the bottom portion or from the distal side upright portion to the bottom portion, the electrode portion facing the receiving space; the proximal side curved portion and the distal side curved portion being deformable in response to expansion and contraction of the expansion body; the electrode portion is being in a floating state with respect to the distal side curved portion and the proximal side curved portion; the expansion body including a plurality of electrode engaging portions that each engage a respective one of the plurality of electrode assemblies; each of the plurality of electrode assemblies including an engaged portion that is engaged with a corresponding one of the electrode engaging portions; each of the electrode engaging portions is provided in at least one of the bottom portion, the proximal side upright portion, and the distal side upright portion of the recessed portion of the expansion body; the expansion body including a proximal side expansion portion extending radially outward from the proximal end fixing portion of the shaft toward a distal direction, and the proximal side expansion portion including an outward curved portion whose distal end is connected to a radially outer end of the proximal side upright portion, the outward curved portion being curved in a convex shape outward in the radial direction; the proximal side upright portion including a first through-hole passing through the expansion body; at least one of the plurality of electrode assemblies including an inner arrangement portion and an outer arrangement portion, the inner arrangement portion extending inside of the proximal side expansion portion from the distal portion of the shaft to the first through-hole, the outer arrangement portion extending along the expansion body from the first through-hole to at least the bottom portion of the recessed portion of the expansion body so as to face the receiving space; the outward curved portion of the proximal side expansion portion is configured to deform in response to the expansion and contraction of the expansion body, the inner arrangement portion is separated from the outward curved portion of the proximal side expansion portion at least when the expansion body is expanded; and the outer arrangement portion is in a floating state with respect to the distal side curved portion and the proximal side curved portion.
2. 2 . The medical device according to claim 1 , wherein the inner arrangement portion extends along an inner side of the expansion body from the distal portion of the shaft to the first through-hole while also extending along the outward curved portion of the proximal side expansion portion.
3. 3 . The medical device according to claim 1 , wherein the expansion body includes a second through-hole in the proximal side curved portion and a third through-hole in the distal side curved portion, the plurality of electrode engaging portions include a first engaging portion between the second through-hole and the third through-hole of the bottom portion, and the at least one of the plurality of electrode assemblies includes a first hook portion that is the engaged portion, the first hook portion being engaged with the first engaging portion by extending from an extension end of the outer arrangement portion, passing through the second through-hole, passing through the third through-hole from a radially inner side of the first engaging portion, and extending to an outer side of the expansion body.
4. 4 . The medical device according to claim 3 , wherein the expansion body includes a fourth through-hole in the distal side upright portion, the plurality of electrode engaging portions include a second engaging portion constituted by an edge portion of the fourth through-hole, and the at least one of the plurality of electrode assemblies includes a second hook portion that is the engaged portion, the second hook portion being engaged with the second engaging portion by extending from an extension end of the first hook portion and passing through the fourth through-hole from the outer side to the inner side of the expansion body.
5. 5 . The medical device according to claim 4 , wherein the second hook portion includes a folded-back portion passing through the fourth through-hole and extending inside the expansion body toward the bottom portion.
6. 6 . The medical device according to claim 4 , wherein the at least one of the plurality of electrode assemblies includes a third hook portion that functions as the engaged portion, the third hook portion being engaged with the first engaging portion by extending from an extension end of the second hook portion, passing through the second through-hole from the inner side of the expansion body, and extending to the outer side of the expansion body.
7. 7 . The medical device according to claim 6 , wherein the at least one of the plurality of electrode assemblies includes a first extension portion extending from an extension end of the third hook portion and extending between the outer arrangement portion and the proximal side upright portion toward the first through-hole, and the medical device further comprises a first cover that covers the proximal side upright portion and the first extension portion.
8. 8 . The medical device according to claim 7 , wherein the at least one of the plurality of electrode assemblies includes the electrode portion on the outer arrangement portion, and the first cover is sandwiched between the outer arrangement portion and the first extension portion.
9. 9 . The medical device according to claim 6 , wherein the plurality of electrode engaging portions include a third engaging portion constituted by an edge portion of the first through-hole, and the at least one of the plurality of electrode assemblies includes a first extension portion extending from an extension end of the third hook portion and extending between the outer arrangement portion and the proximal side upright portion toward the first through-hole, and a fourth hook portion that is the engaged portion, the fourth hook portion being engaged with the third engaging portion by extending from an extension end of the first extension portion and passing through the first through-hole.
10. 10 . The medical device according to claim 9 , wherein the fourth hook portion includes a crank-shaped portion extending from the extension end of the first extension portion, passing through the first through-hole, and extending along the inner side of the expansion body.
11. 11 . The medical device according to claim 10 , wherein the at least one of the plurality of electrode assemblies includes a second extension portion extending from an extension end of the crank-shaped portion and extending along the inner arrangement portion on a radially inner side of the inner arrangement portion, and the medical device further comprises a second cover covering the second extension portion, the inner arrangement portion, and the proximal side expansion portion.
12. 12 . The medical device according to claim 3 , wherein the plurality of electrode engaging portions include a second engaging portion constituted by an edge portion of the third through-hole, and the first hook portion includes a wide portion that is wider than a portion of the first hook portion passing through the third through-hole and is engaged with the second engaging portion.
13. 13 . The medical device according to claim 1 , wherein the expansion body includes a second through-hole in the bottom portion, the plurality of electrode engaging portions include a first engaging portion constituted by an edge portion of the second through-hole, the at least one of the plurality of electrode assemblies includes a first hook portion that is the engaged portion, the first hook portion extending from an extension end of the outer arrangement portion, passing through the second through-hole, and extending to a radially inner side of the bottom portion, and the first hook portion includes a wide portion that is wider than a portion of the first hook portion passing through the second through-hole and is engaged with the first engaging portion.
14. 14 . The medical device according to claim 1 , wherein the expansion body includes a second through-hole in the proximal side curved portion and a fourth through-hole in the distal side upright portion, the plurality of electrode engaging portions include a first engaging portion constituted by an edge portion of the second through-hole and a second engaging portion constituted by an edge portion of the fourth through-hole, the at least one of the plurality of electrode assemblies includes a first hook portion that is the engaged portion, the first hook portion being engaged with the first engaging portion by extending from an extension end of the outer arrangement portion, passing through the second through-hole, passing through the fourth through-hole from a radially inner side of the first engaging portion, and extending to an outer side of the expansion body, and the first hook portion includes a wide portion that is wider than a portion of the first hook portion passing through the fourth through-hole and is engaged with the second engaging portion.
15. 15 . The medical device according to claim 1 , wherein the expansion body includes a second through-hole in the distal side curved portion and a third through-hole in the proximal side curved portion, the plurality of electrode engaging portions include a first engaging portion formed between the second through-hole and the third through-hole, and a fourth engaging portion formed from an edge portion of the first through-hole, and the at least one of the plurality of electrode assemblies includes a first hook portion that is the engaged portion, the first hook portion being engaged with the first engaging portion by extending from an extension end of the outer arrangement portion, passing through the second through-hole, passing through the third through-hole from a radially inner side of the first engaging portion, and extending to an outer side of the expansion body, a first extension portion extending from an extension end of the first hook portion and extending between the outer arrangement portion and the proximal side upright portion toward the first through-hole, and a fourth hook portion that is the engaged portion, the fourth hook portion being engaged with the fourth engaging portion by extending from an extension end of the first extension portion and passing through the first through-hole.
16. 16 . The medical device according to claim 1 , wherein at least one electrode assembly of the plurality of electrode assemblies is bonded and fixed to the expansion body at the proximal side upright portion or the distal side upright portion.
17. 17 . The medical device according to claim 16 , wherein the shaft includes a shaft extension portion extending inside the expansion body along a central axis of the expansion body from the proximal end fixing portion, the shaft also including a distal end fixing portion to which a distal end of the expansion body is fixed, the expansion body includes a distal side expansion portion extending radially outward from the distal end fixing portion of the shaft toward a proximal direction, the distal side expansion portion includes an outward curved portion whose proximal end is connected to an outer end of the distal side upright portion and which is curved in a convex shape outward in the radial direction, the distal side upright portion includes a first through-hole, at least one of the plurality of electrode assemblies includes a shaft arrangement portion extending along the shaft extension portion from the proximal end fixing portion of the shaft to the distal end fixing portion, an inner arrangement portion extending along the inner side of the expansion body from an extension end of the shaft arrangement portion to the first through-hole through a vicinity of the outward curved portion of the distal side expansion portion, and an outer arrangement portion extending along the expansion body from the first through-hole to at least the bottom portion so as to face the receiving space, the outward curved portion of the distal side expansion portion is deformable so that the outward curved portion of the distal side expansion portion deforms in response to the expansion and contraction of the expansion body, the inner arrangement portion is separated from the outward curved portion of the distal side expansion portion at least when the expansion body is expanded, and the outer arrangement portion is in a floating state with respect to the distal side curved portion and the proximal side curved portion.
18. 18 . The medical device according to claim 1 , wherein the expansion body includes a first through-hole in the distal side upright portion, and at least one of the plurality of electrode assemblies includes an inner arrangement portion extending along the inner side of the expansion body from the distal portion of the shaft to the first through-hole of the distal side upright portion beyond the proximal side upright portion, and an outer arrangement portion folded back with respect to the inner arrangement portion and extending along the expansion body from the first through-hole to the bottom portion so as to face the receiving space.
19. 19 . The medical device according to claim 1 , wherein the expansion body includes a second through-hole in the proximal side curved portion, a third through-hole in the distal side curved portion, and a fourth through-hole in the distal side upright portion, the plurality of electrode engaging portions include a first engaging portion formed between the second through-hole and the third through-hole of the bottom portion, and a second engaging portion formed at an edge portion of the fourth through-hole, the at least one of the plurality of electrode assemblies includes a first hook portion that is the engaged portion, the first hook portion being engaged with the first engaging portion by extending from an extension end of the outer arrangement portion, passing through the second through-hole, passing through the third through-hole from a radially inner side of the first engaging portion, and extending to an outer side of the expansion body, and a second hook portion that is the engaged portion, the second hook portion being engaged with the second engaging portion by extending from an extension end of the first hook portion and passing through the fourth through-hole from the outer side to the inner side of the expansion body, and the electrode portion is disposed between the first hook portion and the second hook portion.
20. 20 . The medical device according to claim 1 , wherein the expansion body is comprised of a mesh obtained by braiding a plurality of wires, and at least one electrode assembly of the plurality of electrode assemblies is positioned between plural wires of the plurality of the wires and is engaged and fixed relative to the plural wires.

Description

CROSS-REFERENCES TO RELATED APPLICATIONS This application is a continuation of International Patent Application No. PCT/JP2021/031128 filed on Aug. 25, 2021, which claims priority to Japanese Patent Application No. 2020-142445 filed on Aug. 26, 2020, the entire content of both of which is incorporated herein by reference. TECHNOLOGICAL FIELD The present invention generally relates to a medical device that applies energy to a biological tissue. BACKGROUND DISCUSSION Chronic heart failure is one of known heart diseases. Chronic heart failure is broadly classified into a systolic heart failure and a diastolic heart failure, based on a cardiac function index. In a patient suffering from the diastolic heart failure, myocardial hypertrophy appears, and stiffness (hardness) increases, so that blood pressure increases in a left atrium, and a cardiac pumping function is degraded. Accordingly, the patient shows heart failure symptoms such as a pulmonary edema. In addition, there is another heart disease of a patient that shows the heart failure symptom because blood pressure increases on a right atrium side due to pulmonary hypertension, and the cardiac pumping function is degraded. In recent years, shunt treatments have attracted attention in which, for the patients who suffer from heart failure, a shunt (through-hole) serving as an escape route for increased atrial pressure is formed in an atrial septum, thereby enabling heart failure symptoms to be alleviated. In the shunt treatment, the atrial septum is accessed using an intravenous approaching method, and the through-hole is formed to have a desired size. For example, a medical device disclosed in International Patent Application Publication No. 2019/85841 (WO2019/85841) is used as a medical device for performing the shunt treatment on the atrial septum. SUMMARY In the medical device described in International Patent Application Publication No. 2019/85841, an electrode portion is fixed to a recessed portion of an expansion body. Since a vicinity of a bottom portion of the recessed portion largely deforms when the expansion body is expanded or contracted in a radial direction, it is difficult to dispose the electrode portion in the vicinity of the bottom portion. When the electrode portion is disposed at a position away from the bottom portion of the recessed portion, there is a possibility that an edge portion of the through-hole of the atrial septum cannot be sufficiently heated and cauterized when high frequency energy is applied from the electrode portion to the through-hole. In a case where the edge portion of the through-hole is not sufficiently cauterized, a through-hole having a desired size cannot be obtained after the cauterization. The medical device disclosed here includes an electrode portion provided in an expansion body, and the electrode portion can be disposed at a position close to a bottom portion of a recessed portion. A medical device includes an expansion body configured to expand and contract in a radial direction; an elongated shaft portion including a distal portion that includes a proximal end fixing portion to which a proximal end of the expansion body is fixed; and a plurality of electrode assemblies extending from the proximal end fixing portion of the shaft portion along at least a part of the expansion body. The expansion body includes a recessed portion that is recessed radially inward and that defines a receiving space capable of receiving a biological tissue when the expansion body is expanded. The recessed portion includes a radially innermost bottom portion including a proximal side curved portion and a distal side curved portion, a proximal side upright portion extending radially outward from the proximal side curved portion, and a distal side upright portion extending radially outward from the distal side curved portion. Each of the plurality of electrode assemblies includes an electrode portion disposed along the expansion body from the proximal side upright portion or the distal side upright portion to the bottom portion so as to face the receiving space. The proximal side curved portion and the distal side curved portion are deformable so that proximal side curved portion and the distal side curved portion deform in response to expansion and contraction of the expansion body. The electrode portion is in a floating state with respect to the distal side curved portion and the proximal side curved portion. In the medical device configured as described above, since the electrode portion is provided on the electrode assembly separate from the expansion body, the electrode portion can be disposed at a position close to the radially innermost bottom portion of the recessed portion. Since the electrode portion is not fixed to the proximal side curved portion and the distal side curved portion that deform in response to the expansion and contraction of the expansion body and is in a floating state, the electrode portion disposed at