CN107661141B

CN107661141B - Ablation catheter

Info

Publication number: CN107661141B
Application number: CN201610613440.3A
Authority: CN
Inventors: 庄少春; 曾莉群; 刘鹏; 陈文俊
Original assignee: Lifetech Scientific Shenzhen Co Ltd
Current assignee: Lifetech Scientific Shenzhen Co Ltd
Priority date: 2016-07-29
Filing date: 2016-07-29
Publication date: 2020-08-28
Anticipated expiration: 2036-07-29
Also published as: CN107661141A

Abstract

The invention provides an ablation catheter, which comprises a support body which is not compressible in the radial direction and at least one electrode arranged on the surface of the support body. The support body includes a distal cross-section and a first cross-section. The cross section of the support body corresponding to the far end of the electrode closest to the far end of the support body in the at least one electrode is the first cross section. The radial maximum length of any cross section between the distal end cross section and the first cross section of the support body is smaller than or equal to the radial maximum length of the first cross section.

Description

Ablation catheter

Technical Field

The invention relates to the field of medical instruments, in particular to an ablation catheter.

Background

Hypertension is a common chronic disease, and in its mechanism of formation, the renin-angiotensin-Aldosterone System (RAAS) plays a key role as an important blood pressure regulation System. RAAS maintains the balance of body water, electrolytes, and blood pressure through regulation of the heart, blood vessels, and kidneys. Studies have demonstrated that RAAS causes hypertension through three pathways: (1) RAAS activation causes sodium retention; (2) RAAS activation can increase sympathetic nervous system activity; (3) RAAS activation can directly constrict blood vessels. Among them, renal artery sympathetic nerves play a decisive role in the induction and maintenance of systemic hypertension, and their hyperactivity makes it difficult to lower the blood pressure of hypertensive patients.

Figure 1 shows a typical anatomical structure of a renal artery. The main renal artery 2 has an inlet connected to the aorta 1, and blood flows from the aorta 1 to the kidney through the renal artery 2, the branch blood vessel 31, and the next-stage branch blood vessels 311 and 312 (hereinafter referred to as the second-stage branch blood vessels 311 and 312) branched from the branch blood vessel 31 in this order. Typically, the

secondary branch vessels

311 and 312 have a smaller inner diameter than branch vessel 31. Fig. 2 shows the distribution of renal sympathetic nerves along the wall of the renal artery blood vessel. Renal sympathetic nerve fibers 4 (hereinafter, referred to as nerve fibers 4) distributed in the wall of the renal artery blood vessel are closely related to the renal function. Viewed from the side of the blood vessel, the nerve fibers 4 extend along the blood vessel from the aorta 1 to the kidney 8 via the main renal artery 2 and a renal artery branch vessel 31 (hereinafter referred to simply as the branch vessel 31). The nerve fibres 4 are mainly distributed in the adventitia of the vessel wall through which they pass.

Transcatheter renal artery sympathetic nerve ablation is aimed at ablation of renal artery sympathetic nerves, and the typical action mode of the transcatheter renal artery sympathetic nerve ablation is that electrodes are conveyed into renal artery blood vessels of a patient body through a catheter, and energy is applied to the renal artery blood vessels through the electrodes so as to achieve the purpose of ablating the renal sympathetic nerves in the renal artery blood vessels and reducing the blood pressure of the patient.

A nerve ablation system is disclosed in the prior art (as shown in fig. 3). The system comprises an energy generator 6 and an ablation catheter 5. The energy generator 6 is for emitting energy, such as radio frequency energy. The ablation catheter 5 includes an elongate tubular body 57, a balloon 76 disposed at a distal end of the tubular body 57 (i.e., the end distal from the operator), and an electrode 72 disposed on the balloon 76. The proximal end of the tubular body 57 (i.e., the end remote from the operator) is connected to the energy generator 6 via a lead wire, which transmits energy from the energy generator 6 to the electrode 72. The balloon 76 is a relatively regular, approximately cylindrical, columnar structure. The electrodes 72 can be advanced into a blood vessel and deliver energy from within the blood vessel to the vessel wall, reducing the activity of the nerve fibers 4.

However, when there is an irregular shape in the target blood vessel, such as a renal artery blood vessel entrance or a renal artery stenosis, it is difficult for the electrode to completely adhere to the blood vessel wall, or when the target blood vessel has a small inner diameter and the balloon cannot be fully deployed in the blood vessel, the electrode is difficult to adhere to the blood vessel wall due to obstruction of the balloon, which results in poor ablation effect and low ablation efficiency.

Disclosure of Invention

Therefore, it is necessary to provide an ablation catheter, which has an electrode with good adherence performance, good ablation effect and high ablation efficiency.

In one embodiment, the side of the support body is provided with a groove extending in the axial direction of the support body.

In one embodiment, the width of the groove along the circumferential direction of the side surface of the support body is gradually increased from the distal end to the proximal end, and the electrode is erected on the groove.

In one embodiment, the width of the groove along the circumferential direction of the side surface of the support body is equal from the far end to the near end, the electrode is a linear electrode which is arranged on the side surface of the support body, and the linear electrode is parallel to the axial direction of the support body.

In one embodiment, the support body further has a second cross section located between the first cross section and the proximal cross section thereof, the cross section of the support body corresponding to the proximal end of the electrode closest to the proximal end of the support body in the at least one electrode is the second cross section, and the maximum radial length of the second cross section is smaller than or equal to the maximum radial length of the third cross section.

In one embodiment, the radial maximum length of the first cross section of the support body is less than or equal to 1.1 mm, the radial maximum length of the second cross section is greater than or equal to 2.5 mm and less than or equal to 3.5 mm, and the distance between the first cross section and the second cross section is greater than or equal to 4 mm and less than or equal to 7 mm.

In one embodiment, the radial maximum length of the first cross section of the support body is less than or equal to 0.9 mm, the radial maximum length of the second cross section is greater than or equal to 2 mm and less than or equal to 2.5 mm, and the distance between the first cross section and the second cross section is greater than or equal to 3 mm and less than or equal to 6 mm.

In one embodiment, the radial maximum length of the first cross section of the support body is less than or equal to 2.5 mm, the radial maximum length of the second cross section is greater than or equal to 5mm and less than or equal to 8 mm, and the distance between the first cross section and the second cross section is greater than or equal to 4 mm and less than or equal to 12 mm.

In one embodiment, the radial maximum length of the first cross section of the support body is less than or equal to 1 mm, the radial maximum length of the second cross section is greater than or equal to 2.5 mm and less than or equal to 3.5 mm, and the distance between the first cross section and the second cross section is greater than or equal to 4 mm and less than or equal to 7 mm.

In one embodiment, the support body includes a plurality of support subunits and at least one flexible connection component, two adjacent support subunits in the plurality of support subunits are connected through the flexible connection component, the electrode is an annular electrode, and the annular electrode is sleeved on the peripheral surface of the support subunit.

Compared with the ablation catheter in the prior art, the support body of the electrode of the ablation catheter is radially incompressible, the radial maximum length of any cross section between the far-end cross section of the support body and the first cross section is smaller than or equal to the radial maximum length of the first cross section, so that the electrode arranged on the surface of the support body cannot be blocked by the part of the support body entering a blood vessel and is difficult to be attached to the blood vessel wall, the electrode can obtain good adherence performance directly, a good ablation effect is achieved, and the ablation efficiency is improved.

Drawings

FIG. 1 is a schematic representation of a typical anatomy of a renal artery;

FIG. 2 is a schematic diagram of the distribution of renal sympathetic nerves along the wall of the renal artery blood vessel;

fig. 3 is a schematic structural diagram of a conventional nerve ablation system;

fig. 4 is a schematic structural view of a nerve ablation system provided in accordance with a first embodiment of the present invention;

fig. 5 is a schematic structural view of an ablation catheter of the nerve ablation system of fig. 4;

FIG. 6 is a schematic illustration of the ablation catheter of FIG. 5 after it has entered a branch of a renal artery;

FIG. 7 is a schematic structural view of an ablation assembly provided in accordance with a second embodiment of the invention;

fig. 8 is a schematic structural view of an ablation assembly provided in accordance with a third embodiment of the invention;

fig. 9 is a schematic structural view of an ablation catheter provided in accordance with a fourth embodiment of the invention;

fig. 10 is a schematic structural view of an ablation catheter provided in accordance with a fifth embodiment of the invention;

FIG. 11 is a schematic view of the ablation catheter of FIG. 10 after being engaged with a vessel wall;

fig. 12 is a schematic structural view of an ablation catheter provided in accordance with a sixth embodiment of the invention;

fig. 13 is a schematic structural view of an ablation catheter provided in accordance with a seventh embodiment of the invention;

fig. 14 is a side schematic view of the support body of the ablation catheter of fig. 13.

Detailed Description

In order to make the aforementioned objects, features and advantages of the present invention comprehensible, embodiments accompanied with figures are described in detail below. In the following description, numerous specific details are set forth in order to provide a thorough understanding of the present invention. This invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein, but rather should be construed as broadly as the present invention is capable of modification in various respects, all without departing from the spirit and scope of the present invention.

In the field of intervention, the end proximal to the operator is generally referred to as the proximal end, and the end distal to the operator is generally referred to as the distal end. It should also be noted that, in the present application, the maximum radial length of the cross-section refers to the distance between the two points that are farthest apart on the cross-section.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. The terminology used in the description of the invention herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

Referring to fig. 4, a nerve ablation system 100 according to a first embodiment of the present invention includes an energy generator 10 and an ablation catheter 20 for ablating a target vessel. The energy generator 10 is a common apparatus for those skilled in the art, and the present invention will not be described in detail with respect to the structure and principle of the energy generator 10.

The ablation catheter 20 includes a hollow elongate tubular body 21 and an ablation assembly 23 disposed at a distal end of the tubular body 21. The proximal end of the tubular body 21 is connected to the energy generator 10 by a lead (not shown) for transmitting energy from the energy generator 10 to the ablation assembly 23. The ablation assembly 23 includes a support 231 and at least one electrode 233 disposed on the support 231.

The support body 231 has an axial direction and a radial direction. The axial direction of the support body 231 coincides with the axial direction of the tubular body 21, and the radial direction thereof is a direction perpendicular to the axial direction. A cross section is defined as a section along a radial direction, i.e., a section perpendicular to the axial direction, and a circumferential direction is defined as a direction of rotation about the axial direction.

Referring also to fig. 5, support 231 is radially incompressible and has a distal cross-section 234, a proximal cross-section 235, a first cross-section 236, and a second cross-section 237. The first and

second cross-sections

236, 237 lie between the distal and

proximal cross-sections

234, 235, with the first cross-section 236 being closer to the distal cross-section 234 than the second cross-section 237. The distal ends of all of the electrodes 233 may be located within the same cross-section or may be located within different cross-sections. When the distal ends of all the electrodes 233 are located within the same cross section, the cross section is defined as a first cross section 236. When the distal ends of all the electrodes 233 are not located in the same cross section, the cross section of the support 231 corresponding to the distal end of the electrode closest to the distal end of the support 231 among all the electrodes 233 is defined as a first cross section 236. Similarly, the proximal ends of all of the electrodes 233 may be located within the same cross-section or may be located within different cross-sections. When the proximal ends of all of the electrodes 233 lie within the same cross-section, the cross-section is defined as a second cross-section 237. When the proximal ends of all the electrodes 233 are not located in the same cross section, the cross section of the support 231 corresponding to the proximal end of the electrode closest to the proximal end of the support 231 among all the electrodes 233 is the second cross section 237. That is, all of the electrodes 233 are located between the first cross-section 236 and the second cross-section 237, and the surface of the support body 231 located between the first cross-section 236 and the second cross-section 237 defines an electrode zone, the distal cross-section of which is the first cross-section 236 and the proximal cross-section of which is the second cross-section 237. The radial maximum length of any cross section between the distal cross section 234 and the first cross section 236 is less than or equal to the radial maximum length of the first cross section 236. Because of the flexibility of the blood vessel, the electrode 233 of the ablation assembly 23 may enter the target blood vessel when the outer diameter of the ablation assembly 23 at the first cross-section 236 is less than or equal to the inner diameter at the blood flow entry site of the target blood vessel. That is, in actual use, the ablation assembly 23 having an outer diameter of the ablation assembly 23 at the first cross-section 236 that is less than or equal to the inner diameter is selected based on the inner diameter of the target vessel at the blood flow inlet.

When the radial maximum length of the distal cross section is less than or equal to the radial maximum length of the first cross section, the radial maximum length of the first cross section is less than the radial maximum length of the second cross section, and the radial maximum length of the second cross section is less than or equal to the radial maximum length of the proximal cross section, the distal cross section of the support body 231 can rapidly pass through the position with the irregular shape in the blood vessel, and the proximal cross section is larger and is difficult to pass through the position with the irregular shape in the blood vessel to plug the position, so that the support body 231 can be effectively positioned at the position with the irregular shape in the blood vessel, the operation time is shortened, and the ablation. In this embodiment, the support 231 comprises a truncated cone (i.e., a truncated cone); the distal cross-section 234, the proximal cross-section 235, the first cross-section 236, and the second cross-section 237 are circular; the radial maximum length of the distal cross-section, the radial maximum length of the proximal cross-section, the radial maximum length of the first cross-section, and the radial maximum length of the second cross-section are diameters of respective circles.

Preferably, with configuration one: the maximum radial length of the first cross-section is less than or equal to 1.1 mm, the maximum radial length of the second cross-section is greater than or equal to 2.5 mm and less than or equal to 3.5 mm, and the distance between the first cross-section 236 and the second cross-section 237 is greater than or equal to 4 mm and less than or equal to 7 mm, so that the ablation assembly 23 can be positioned at the entrance of the branch vessel 31 of most patients as shown in fig. 1. Specifically, in this embodiment, the radial maximum length of the distal cross-section is 1 mm, the radial maximum length of the proximal cross-section is 3 mm, the radial maximum length of the first cross-section is 1.1 mm, the radial maximum length of the second cross-section is 2.8 mm, and the distance between the first cross-section 236 and the second cross-section 237 is 4.2 mm.

The electrode 233 is disposed on a side surface of the support 231 between the first cross section 236 and the second cross section 237. In this embodiment, the number of the electrodes 233 is four, and each electrode 233 is a linear electrode; the four electrodes 233 on the supporting body 231 are distributed in a central symmetry manner with the axial direction of the supporting body 231 as a symmetry axis, that is, the extending direction of each electrode 233 on the supporting body 231 from the far end to the near end forms an acute angle with the axial direction of the supporting body 231 from the far end to the near end, so that after entering a target blood vessel, the plurality of electrodes 233 can have a larger contact area with the target blood vessel wall, and the ablation efficiency is improved.

Referring to fig. 6, the ablation assembly 23 of the ablation catheter 20 may be advanced through a puncture site in the femoral artery of a patient and advanced into the aorta 1 along a previously deployed delivery sheath 9. The ablation assembly 23 is movable within the renal artery trunk 2. The operator can select a branch vessel 31 having an inner diameter of about 2.5 mm as the target vessel. The distal cross-section 234 is accessible into the branch vessel 31, while the proximal cross-section 237 is not. Upon application of a suitable pushing force to the catheter body 21 in the axial direction of the ablation catheter 20, the ablation assembly 23 will be positioned at the target vascular blood flow portal with at least a portion of the electrodes 233 in contact with the target vessel wall, as if the mouth of the bottle were plugged with a tapered stopper. Based on this, since the electrode 233 is located between the first cross section and the second cross section, the energy generated by the energy generator 10 can be delivered to the target tissue through the electrode 233, thereby performing an ablation action on the target tissue. The ablation assembly 23 is circumferentially arranged with a plurality of electrodes 233 arranged such that when the ablation assembly 23 is positioned at a target vessel entry location, the plurality of electrodes 233 are simultaneously in contact with the vessel wall in the circumferential direction to simultaneously ablate a plurality of locations in the circumferential direction of the vessel wall.

It will be appreciated that in other embodiments, the support 231 of the present invention may be effectively positioned at the target vascular access port only when the positions of the first cross section 236 and the distal cross section 234 coincide, i.e., the radial maximum length of the first cross section is equal to the radial maximum length of the distal cross section, under other conditions. It will also be appreciated that in other embodiments, the second cross-section 237 and the proximal cross-section 235 may coincide under other conditions, i.e., the radial maximum length of the second cross-section is equal to the radial maximum length of the proximal cross-section, which may also achieve the purpose of the support body 231 of the present invention being effectively positioned at the target vascular access.

It is understood that in other embodiments, the distal end of the support 231 may have a hemispherical shape, and in this case, the distal cross-section 234 is a tangent point on a plane tangent to the most distal end of the hemispherical shape, i.e., the radial maximum length of the distal cross-section approaches zero, which also achieves the purpose that the support 231 of the present invention can be effectively positioned at the entrance of the target blood vessel.

Referring to fig. 7, an ablation assembly 23a according to a second embodiment of the present invention is substantially the same as the ablation assembly 23, except that the ablation assembly 23a includes a radially incompressible support 231a and six wire electrodes 233a disposed on the support 231 a. The axial and radial definitions of the support 231a are the same as the axial and radial definitions of the support 231, respectively, and are not described herein again.

The support 231a is radially incompressible and comprises a truncated hexagonal pyramid, that is, the support 231a comprises a truncated conical structure, and the cross-section of the truncated conical structure is hexagonal. Specifically, support 231 has a hexagonal distal cross-section 234a, a hexagonal proximal cross-section 235a, a hexagonal first cross-section 236a, and a hexagonal second cross-section 237 a. The distal cross-section 234a is the distal cross-section of the support 231 a. The proximal cross-section 235a is a proximal cross-section of the support 231 a. The first and second cross-sections 236a, 237a are located between the distal and proximal cross-sections 234a, 235a, and the first cross-section 236a is closer to the distal cross-section 234a than the second cross-section 237 a. The cross section of the support 231a at the distal end of the electrode 233a closest to the distal end of the support 231a in the at least one electrode 233a is the first cross section 236 a. The cross section of the support 231a at the proximal end of the electrode 233a closest to the proximal end of the support 231a in the at least one electrode 233a is the second cross section 237 a. The radial maximum length of either cross-sectional plane between the distal cross-section 234a and the first cross-section 236a is less than or equal to the radial maximum length of the first cross-section 236a, and the outer diameter of the ablation assembly 23a at the first cross-section 236a is less than or equal to the inner diameter at the target blood flow entrance. When the radial maximum length of the distal cross section is less than or equal to the radial maximum length of the first cross section, the radial maximum length of the first cross section is less than the radial maximum length of the second cross section, and the radial maximum length of the second cross section is less than or equal to the radial maximum length of the proximal cross section, the distal cross section of the support 231a is smaller, the proximal cross section is larger, the support 231a can be effectively positioned at the target vascular entrance, the neuromodulation efficiency is improved, and the operation time is shortened.

Preferably, configuration two is employed: the maximum radial extent of the first cross-section is less than or equal to 0.9 mm, the maximum radial extent of the second cross-section is greater than or equal to 2 mm and less than or equal to 2.5 mm, and the distance between the first cross-section 236a and the second cross-section 237a is greater than or equal to 3 mm and less than or equal to 6 mm, which allows the ablation assembly 23a to be positioned at the blood flow entry site of the secondary branch vessel 311 in most patients as shown in fig. 1. Specifically, in the present embodiment, the maximum radial length of the first cross section is 0.8 mm, the maximum radial length of the second cross section is 2.3 mm, and the distance between the first cross section 236a and the second cross section 237a is 4 mm.

The six wire electrodes 233a are located at the electrode area, i.e. between the first cross section 236a and the second cross section 237a, and one wire electrode 233a is located at one edge of the support 231 a. The electrodes 233a arranged on the edges of the supporting body 231a can apply greater pressure to the blood vessel wall, so that the blood vessel wall is locally deformed greatly, the electrodes 233a can sink into the blood vessel wall, and the electrodes 233a sinking into the blood vessel wall can modulate nerves in the blood vessel wall which are distributed farther away from the inner wall of the blood vessel.

It is understood that in other embodiments, the supporting body 231a may also include other truncated pyramids such as a truncated pentagonal pyramid, a truncated quadrangular pyramid, or a truncated triangular pyramid. It is also understood that the ribs of the support 231a may have a curved configuration.

Referring to fig. 8, an ablation assembly 23b according to a third embodiment of the present invention is substantially the same as ablation assembly 23 except that the radially incompressible support body 231b of ablation assembly 23b comprises a truncated elliptical cone, i.e., the support body 231b comprises a truncated conical structure having an elliptical cross-section that is not axisymmetric. The plurality of electrodes 233b of ablation assembly 23b are distributed proximate to both ends of the major axis of the ellipse to facilitate contact of electrodes 233b with the vessel wall. In addition, just because a plurality of electrodes 233b distribute in the position that is close to oval major axis both ends, when supporter 231 that has oval cross section is positioned at target blood vessel blood flow entrance, the position that is close to major axis both ends on its cross section contacts with the vascular wall, and the position that is close to minor axis both ends on the cross section then does not contact with the vascular wall, and blood can flow through the clearance of supporter 231 and vascular wall like this, and the blood stream that flows through the clearance constantly takes away the heat of electrode 233b, can play the cooling effect to electrode 233b to avoid electrode 233b to produce the emergence of excessive damage because of the high temperature to adjacent tissue.

Referring to fig. 9, an ablation catheter 20c according to a fourth embodiment of the present invention is substantially the same as the ablation catheter 20, and includes a hollow elongated tubular body 21c and an ablation element 23c disposed at a distal end of the tubular body 21 c.

The tubular body 21c is substantially identical to the tubular body 21 and will not be described in detail herein.

Ablation assembly 23c includes a radially incompressible support 231c and a plurality of electrodes 233c disposed on support 231.

Support 231c is substantially identical to support 231, having a distal cross-section 234c, a proximal cross-section 235c, a first cross-section 236c, and a second cross-section 237 c. The definitions of the distal cross-section 234c, the proximal cross-section 235c, the first cross-section 236c and the second cross-section 237c are the same as the definitions of the distal cross-section 234, the proximal cross-section 235, the first cross-section 236 and the second cross-section 237 in the first embodiment, and thus, no further description is provided. The distal cross-section 234c has a radially greatest length that is less than or equal to the radially greatest length of the first cross-section 236c, the first cross-section 236c has a radially greatest length that is less than the radially greatest length of the second cross-section 237c, and the second cross-section 237c has a radially greatest length that is less than or equal to the radially greatest length of the proximal cross-section 235 c. The radial maximum length of either cross-sectional plane between the distal cross-section 234c and the first cross-section 236c is less than or equal to the radial maximum length of the first cross-section 236c, and the outer diameter of the ablation assembly 23c at the first cross-section 236c is less than the inner diameter at the blood flow entrance of the target vessel. Preferably, the configuration three is adopted: the maximum radial extent of the first cross-section is less than or equal to 2.5 mm, the maximum radial extent of the second cross-section is greater than or equal to 5mm and less than or equal to 8 mm, and the distance between the first cross-section 236c and the second cross-section 237c is greater than or equal to 4 mm and less than or equal to 12 mm, which allows the ablation assembly 23d to be positioned at the blood flow entry site of the renal artery trunk 2 of most patients as shown in fig. 1. Specifically, in the present embodiment, the maximum radial length of the first cross section is 2 mm, the maximum radial length of the second cross section is 6 mm, and the distance between the first cross section 236c and the second cross section 237c is 8 mm.

The supporting body 231c is different from the supporting body 231 in that the side surface of the supporting body 231c is provided with a plurality of grooves 238c extending along the axial direction of the supporting body 231c, and the circumferential length of each groove 238c on the side surface of the supporting body 231d is gradually increased from the distal end to the proximal end of the supporting body 238c, so that a protrusion 239c is formed between two adjacent grooves 238 c; the support 231c is a hollow structure having a guide wire cavity 232c axially penetrating the support 231c, the guide wire cavity 232c is communicated with the lumen of the tubular body 21c, so that the distal end of the guide wire can enter the guide wire cavity 231c of the support 231c through the lumen of the tubular body 21 c. The guidewire lumen 232c has a diameter greater than 0.4 mm and less than 1.5 mm to facilitate a smoother guidewire entry into the target vessel. In this embodiment, the guidewire lumen 232c has a diameter of 1 mm. It is understood that in other embodiments, the guide wire lumen 231c of the support body 231c may be omitted according to practical situations.

The plurality of electrodes 233c are located at an electrode region, i.e., between the first cross section 236c and the second cross section 237c, and the plurality of electrodes 233c are different from the plurality of electrodes 233. Specifically, each electrode 233c is arc-shaped, and each electrode 233c is erected on one groove 238c, that is, two ends of each electrode 233c are respectively arranged on two adjacent protrusions 239 c. As such, when the support 231c is positioned at the target blood vessel blood flow entrance, blood flow may flow through the channel 238c toward the distal end of the support 231 c. The blood flowing through the groove 238c continuously carries away the heat of the electrode 233c, and the electrode 233c is cooled, so that the electrode 233c is prevented from being excessively damaged to adjacent tissues due to overhigh temperature.

When a doctor performs a surgical operation, the guide wire can be firstly fed into a target blood vessel to establish a track, and then the ablation assembly 23c on the ablation catheter 20c is conveyed to a blood flow inlet of the target blood vessel along the guide wire track established by the guide wire.

Referring to fig. 10, an ablation catheter 20d according to a fifth embodiment of the present invention is substantially the same as the ablation catheter 20c, and includes a hollow elongated tubular main body 21d and an ablation element 23d disposed at a distal end of the tubular main body 21 d. The tubular body 21d is substantially identical to the tubular body 21d and will not be described in detail herein.

Ablation assembly 23d includes a radially incompressible support 231d, an electrode 23d1 disposed on support 231d, an electrode 23d2, an electrode 23d3, and an electrode 23d 4.

Support 231d is substantially identical to support 231c, having a distal cross-section 234d, a proximal cross-section 235d, a first cross-section 236d, and a second cross-section 237 d. The definitions of the distal cross-section 234d, the proximal cross-section 235d, the first cross-section 236d and the second cross-section 237d are the same as the definitions of the distal cross-section 234, the proximal cross-section 235, the first cross-section 236 and the second cross-section 237 in the first embodiment, and thus, no further description is provided. The radial maximum length of the distal cross-section 234d is less than or equal to the radial maximum length of the first cross-section 236d, the radial maximum length of the first cross-section 236d is less than the radial maximum length of the second cross-section 237d, and the radial maximum length of the second cross-section 237d is less than or equal to the radial maximum length of the proximal cross-section 235 d. The support 231d is provided at a side surface thereof with a plurality of grooves 238d extending in the axial direction of the support 231 d.

The support 231d is a hollow structure and has a guide wire cavity 232d axially penetrating the support 231d, and the guide wire cavity 232d is communicated with the lumen of the tubular body 21d, so that the distal end of the guide wire can enter the guide wire cavity 232d of the support 231d through the lumen of the tubular body 21 d. The guidewire lumen 232d has a diameter greater than 0.4 mm and less than 1.5 mm to facilitate a smoother guidewire entry into the target vessel. In this embodiment, the guidewire lumen 232d has a diameter of 0.8 mm. It is understood that in other embodiments, the guidewire lumen 231d of the support body 231d may be omitted according to the actual situation.

The support 231d differs from the support 231c in that the circumferential length of each groove 238d on the side of the support 231d is equal from the distal end to the proximal end of the support 238d, such that a plate-like projection 239d is formed between two adjacent grooves 238 d.

Each of the electrode 23d1, the electrode 23d2, the electrode 23d3, and the electrode 23d4 is located between the first cross-section 236d and the second cross-section 237 d. Each of the electrode 23d1, the electrode 23d2, the electrode 23d3, and the electrode 23d4 is linear. Each of the electrodes 23d1, 23d2, 23d3 and 23d4 is provided on a side of one of the plate-like projections 239d away from the axis of the support 231d, and the longitudinal direction of each electrode is parallel to the axial direction of the support 231 d. As such, when the support 231d is positioned at the target blood vessel blood flow entrance, blood flow may flow through the channel 238d toward the distal end of the support 231 d. The blood flowing through the groove 238d continuously carries away heat of the electrodes around the groove 238d, so as to cool the electrodes around the groove 238d and avoid excessive damage to adjacent tissues caused by overhigh temperature of the electrodes around the groove 238 d.

In addition, in the present embodiment, the longitudinal direction of each of the electrode 23d1, the electrode 23d2, the electrode 23d3, and the electrode 23d4 is parallel to the axial direction of the support 231 d. When support 231d is in contact with the vessel wall at the entry location of branch vessel 31, the cross-section of branch vessel 31 and the cross-section of ablation assembly 23d at the location of contact are as shown in fig. 11. In the figure, the thinner section lines represent the cross-section of the branch vessels 31, the thicker section lines represent the cross-section of the ablation assembly 23d, and the nerve fibers 4 are distributed in the vessel wall. The vessel wall over the entire cross section can be seen as a structure comprising vessel wall tissue 314, vessel wall tissue 315, vessel wall tissue 316, and vessel wall tissue 317, with each of the vessel wall tissue 314, vessel wall tissue 315, vessel wall tissue 316, and vessel wall tissue 317 disposed between two adjacent electrodes. In this case, energy from an energy generator (not shown) can establish a bipolar electric field between two adjacent electrodes. The vascular wall tissue between two adjacent electrodes is acted by the bipolar electric field, the temperature will rise, and when the temperature rises to a certain degree, the cells in the tissue, including the cells of the nerve fibers 4, will be damaged, so that the activity of the renal sympathetic nerve is reduced. The advantages of the bipolar field solution over the unipolar (monopolar) field solution are: on one hand, the modulated vascular wall tissue is between two adjacent electrodes, and the modulation range is more definite; on the other hand, in the technical scheme of the unipolar electric field, the modulated vascular wall tissue is a local tissue in contact with the electrode, and in order to achieve a sufficient modulation range, the size of the electrode is often made larger, while in the technical scheme of the bipolar electric field, the modulated vascular wall tissue is distributed between two adjacent electrodes, so that the size of the electrode can be designed to be smaller, the heat productivity of the electrode is smaller, and the injury of the intima of the blood vessel in direct contact with the electrode is reduced. In addition, in practical operation, according to actual needs, in a certain time period, a first bipolar electric field is established between the two electrodes 23d1 and 53d4 at the two ends of the blood vessel wall tissue 314 in the circumferential direction, a second bipolar electric field is established between the two electrodes 53d2 and 53d3 at the two ends of the blood vessel wall tissue 316 in the circumferential direction, the potential difference between the electrode 23d1 and the electrode 23d2 is zero, and the potential difference between the electrode 23d3 and the electrode 23d4 is zero, so that only the blood vessel wall tissue 314 and the blood vessel wall tissue 316 in the two bipolar electric fields are modulated, and the blood vessel wall tissue 315 and the blood vessel wall tissue 317 are not modulated; in another time period according to actual needs, a third bipolar electric field is established between the two electrodes 23d1 at the two ends of the blood vessel wall tissue 315 in the circumferential direction and the electrode 23d2, a fourth bipolar electric field is established between the two electrodes 23d3 at the two ends of the blood vessel wall tissue 317 in the circumferential direction and the electrode 23d4, the potential difference between the electrode 23d1 and the electrode 23d4 is zero, and the potential difference between the electrode 23d2 and the electrode 23d3 is zero, only the blood vessel wall tissue 315 and the blood vessel wall tissue 317 in the third and fourth bipolar electric fields are modulated, and the blood vessel wall tissue 314 are not modulated. It is also understood that the number of the sheet-like protrusions 239c may also be five, seven or more, and the number of the corresponding electrodes may also be five, seven or more, and according to actual needs, different combination relationships may be formed among the plurality of electrodes to form bipolar electric fields at different positions, so as to modulate the vascular wall tissue of the target blood vessel in the entire circumferential direction or modulate a certain proportion of the vascular wall tissue of the target blood vessel in the entire circumferential direction.

Referring to fig. 12, an ablation catheter 20e according to a sixth embodiment of the present invention includes a catheter body 21e and an ablation assembly 23 e. Ablation assembly 23e includes a radially incompressible support 231. The supporting body 231 includes a first supporting subunit 231e of a truncated cone shape, a second supporting subunit 232e of a truncated cone shape, and a third supporting subunit 233e of a truncated cone shape, which are connected. The radial maximum length of the proximal end face of each of the first support subunit 231e, the second support subunit 232e and the third support subunit 233e is smaller than the radial maximum length of the distal end face of the same support subunit. The second supporting subunit 232e is located between the first supporting subunit 231e and the third supporting subunit 233e, and the first supporting subunit 231e is closer to the distal end of the ablation element 23e than the third supporting subunit 233 e. The first supporting subunit 231e is connected with the second supporting subunit 232e through a flexible connecting component 234 e; the second support subunit 232e is also connected to the third support subunit 233e by a flexible connecting member 234 e. In this manner, ablation assembly 23a, which includes a plurality of support subunits, has the characteristic of being axially flexible to facilitate passage through a number of tortuous vascular sites. Flexible connecting member 234e is a flexible solid tube or hollow tube. Preferably, in this embodiment, flexible connecting member 234e is a solid tube of block polyetheramide with a woven mesh.

It is understood that in other embodiments, the flexible connecting member 234e may be a hollow block polyetheramide tube with a woven mesh. It will also be appreciated that in other embodiments, the number of supports in ablation assembly 23e may be two, four, or more. It will also be appreciated that in other embodiments, the support body in ablation assembly 23e may be hollow or solid. It is also understood that in other embodiments, the shapes of the first supporting subunit 231e, the second supporting subunit 232e and the third supporting subunit 233e may be the same or different, for example, when the shapes of the plurality of supporting subunits are the same, the shapes of the first supporting subunit 231e, the second supporting subunit 232e and the third supporting subunit 233e may also be truncated prisms, truncated cones, truncated elliptical cones, truncated square cones, truncated pentapyramids or truncated hexapyramids; for example, when the shapes of the plurality of supporting sub-units are different, one of the first supporting sub-unit 231e, the second supporting sub-unit 232e and the third supporting sub-unit 233e is a circular truncated cone, and the other two supporting units are truncated prisms, truncated cones, truncated elliptical cones, truncated square cones, truncated pentapyramids, truncated hexagonal pyramids, and the like, and may be set according to actual needs.

The first supporting subunit 231e is also provided with a closed ring electrode 235e on the peripheral surface; the second supporting subunit 232e is also provided with a closed ring electrode 236e on the circumferential surface; the third support subunit 233e is also provided on its peripheral surface with a ring electrode 237e having an opening.

It should be noted that, in this embodiment, the distal cross section of the first supporting subunit 231e is the distal cross section of the supporting body 231; the proximal cross section of the third supporting unit 233e is the proximal cross section of the supporting body 231; the cross section of the first supporting unit 231e at which the distal end of the electrode 235e is located is the first cross section of the supporting body 231; the cross-section of the third support subunit 233e at the proximal end of the electrode 237e is the second cross-section of the support 231. Preferably, the configuration four is adopted: the maximum radial length of the first cross-section is less than or equal to 1 mm, the maximum radial length of the second cross-section is greater than or equal to 2.5 mm and less than or equal to 3.5 mm, and the distance between the first cross-section and the second cross-section is greater than or equal to 4 mm and less than or equal to 7 mm, enabling the ablation assembly 23e to be positioned at the entrance site of a blood vessel having an inner diameter greater than 1 mm and less than 3 mm. In this embodiment, the maximum radial length of the first cross-section is 0.9 mm, the maximum radial length of the second cross-section is 2.8 mm, and the distance between the first cross-section and the second cross-section is 5 mm.

It is understood that, according to actual needs, the ring-shaped electrode in the present embodiment may also be replaced by a linear electrode, an arc-shaped electrode, or other shaped electrodes, in which case, the cross section of the first supporting unit 231e closest to the distal end of the electrode thereon is the first cross section of the supporting body 231, and the cross section of the third supporting subunit 233e closest to the proximal end of the electrode thereon is the second cross section of the supporting body 231.

Preferably, in this embodiment, a temperature sensing element 238e is disposed on the peripheral surface of the third supporting subunit 233e at a position close to the opening of the ring electrode 237e, so as to detect the temperature of the ring electrode 237 e. It is understood that in other embodiments, the ring electrode 235e or the ring electrode 236e may be a ring electrode with an opening. It is also understood that in other embodiments, the temperature sensitive element 238e may be disposed on the second supporting subunit 232e and/or the first supporting subunit 231e to detect the temperature of the corresponding electrode.

The ablation assembly 23e further includes a guide segment 239e coupled to the distal end of the first support subunit 231e to better guide the ablation assembly 23e into the target vessel. Preferably, in this embodiment, the guide segment 239e is substantially J-shaped and is integrally formed with the first support subunit 231 e.

The guide segment 239e can be advanced into the target vessel when the operator applies a pushing force along the axial direction of the ablation assembly 23 e. It will be appreciated that if the inner diameter at the blood flow entrance of the target vessel is slightly smaller than the outer diameter of the ablation assembly 23e at the distal end of the electrode 235e on the first support subunit 231e, then the target vessel can be slightly dilated and the electrode 235e can contact the vessel wall after the operator applies a suitable pushing force; if the inner diameter at the blood flow inlet of the target blood vessel is larger than the maximum outer diameter of the ablation assembly 23e where the electrode 235e is located and smaller than the outer diameter of the ablation assembly 23e at the distal end of the electrode 236e, the first supporting subunit 231e enters the target blood vessel and the second supporting subunit 232e can expand the target blood vessel properly after the operator applies a proper pushing force, so that the electrode 236e can contact with the blood vessel wall; if the inner diameter at the blood flow entrance of the target vessel is greater than the maximum outer diameter of ablation assembly 23e where electrode 236e is located, and less than the outer diameter of ablation assembly 23e at the proximal end of electrode 237e, the operator applies the appropriate pushing force, electrode 235e and electrode 236e both enter the vessel, and electrode 237e can contact the target vessel wall; if the inner diameter of the blood flow entrance of the target blood vessel wall is larger than the diameter of the proximal end of the third support subunit 233e, the ablation assembly 23e can enter the blood vessel completely, and the operator can continue to apply the pushing force to move the ablation assembly 23e to the branch of the blood vessel, so as to search the branch with the proper inner diameter as the target blood vessel.

Referring to fig. 13 and 14, an ablation catheter 20f according to a seventh embodiment of the present invention, which is substantially the same as the ablation catheter 20e, includes a catheter body 21f and an ablation assembly 23 f. The ablation assembly 23f includes a radially incompressible support 231 and three electrodes (i.e., a ring electrode 237f, a ring electrode 238f, and a ring electrode 239f) disposed on the support 231. The supporting body 231 includes a first supporting subunit 231f, a second supporting subunit 232f, and a third supporting subunit 233f

The radial maximum length of the proximal end face of each of the first support subunit 231f, the second support subunit 232f and the third support subunit 233f is smaller than the radial maximum length of the distal end face of the same support subunit. The second supporting subunit 232f is located between the first supporting subunit 231f and the third supporting subunit 233f, and the first supporting subunit 231f is closer to the distal end of the ablation element 23f than the third supporting subunit 233 f. The first supporting subunit 231f is connected with the second supporting subunit 232f through a flexible connecting component 234 f; the second support subunit 232f is also connected to the third support subunit 233f by a flexible connecting member 234 f. In this manner, ablation assembly 23f, which includes a plurality of struts, has the characteristic of being axially flexible to facilitate passage through some tortuous vascular sites. The flexible connecting member 234f is a flexible solid tube or a hollow tube. Preferably, in this embodiment, the flexible connecting member 234f is a hollow block polyetheramide tube with a woven mesh. It is understood that in other embodiments, flexible connecting member 234f may be a solid tube of block polyetheramide with a woven mesh. It is also understood that in other embodiments, the number of supports in the ablation assembly 23f may be two, four, or more. It should be noted that the definitions of the distal cross section, the proximal cross section, the first cross section and the second cross section of the supporting body 231 of the ablation assembly 23f are the same as the definitions of the distal cross section, the proximal cross section, the first cross section and the second cross section of the supporting body 231 of the ablation assembly 23e, and the description thereof is omitted here.

Ablation assembly 23f differs from ablation assembly 23e in that: the proximal end portion of the first supporting subunit 231f is recessed toward the distal end of the first supporting subunit 231f to form a first groove 235f, and the distal end of the second supporting subunit 232f is received in the first groove 235 f; the proximal end portion of the second support subunit 232f is recessed toward the distal end of the second support subunit 232f to form a second recess 236f, and the distal end of the third support subunit 233f is received in the second recess 236 f. Such a nested configuration has the advantage of not only increasing the compliance of ablation assembly 23f, but also not necessarily increasing the length of ablation assembly 23f, directly making the construction of an ablation catheter having ablation assembly 23f more compact.

It is understood that the radial maximum length of the first cross section, the radial maximum length of the second cross section and the distance between the first cross section and the second cross section of the support body in the ablation assembly of each of the above embodiments can be set according to actual needs, that is, the radial maximum length of the first cross section, the radial maximum length of the second cross section and the distance between the first cross section and the second cross section of the support body in the ablation assembly of each of the above embodiments can be set according to the actual needs according to the configuration one, the configuration two, the configuration three or the configuration four.

It should be noted that, according to actual needs, the material of the electrode may be a metal with a relatively high density, such as platinum, gold, tantalum, or other metals or alloys that are difficult to transmit X-rays. In this way, the doctor can see the image of the electrode through an X-ray device such as a DSA device (digital subtraction angiography technique device), facilitating the operation of the operation. It should also be noted that, according to actual needs, the support of the ablation assembly may also comprise a material that is hard to transmit X-rays, and preferably, the support of the ablation assembly may be made of a block polyether amide resin (Pebax) containing barium sulfate in a certain proportion to facilitate the surgical operation. It should also be noted that in some embodiments, the electrode and the support body may be made of a single-piece structure made of the same material, and such a single-piece structure not only has the characteristic of the support body supporting the electrode, but also has the function of the electrode, for example, the support body itself is made of platinum-iridium alloy and is connected with the energy generator through a lead wire arranged in the catheter body, so that the support body has the function of the electrode at the same time. It should also be noted that, in order to pass through some curved paths, in some embodiments, the support body may be configured to have a certain axial flexibility, for example, the support body made of silicone material with shore hardness of 30A to 70A has a certain axial flexibility. It is also noted that in some embodiments, if the ablation assembly is not significantly flexible, it may be desirable to limit its axial length to facilitate passage through some curved paths, for example, the axial length of the ablation assembly that is not significantly flexible may be less than 7 mm, preferably less than 5.5 mm.

It should be noted that, the distal end of the ablation assembly in the first to fifth embodiments may be provided with a guiding section according to actual needs, and if the length of the guiding section is too long, the guiding section may be blocked and bent in a branch vessel of a target vessel, so as to generate a force that blocks the ablation assembly from clinging to the target vessel, thereby reducing ablation efficiency; if the length of the guiding segment is too short, the guiding effect is poor, so that the guiding segment has a length ranging from 30 mm to 75 mm, preferably the guiding segment 239e has a length ranging from 40 mm to 65 mm, such as 55mm, in order to enable the operator to more smoothly position the ablation assembly at the blood flow entrance of the target blood vessel.

It is understood that the support bodies of the first to third embodiments and the sixth to seventh embodiments may also have a guide wire lumen as the support body of the fourth embodiment. It will also be appreciated that the struts of the fourth and fifth embodiments may also be provided without a guidewire lumen, as the struts of the first embodiment.

It will also be appreciated that the ablation catheter in the above embodiments may also have an irrigation lumen for irrigating fluid (e.g., saline or contrast media); the inlet of the irrigation lumen may be disposed at the proximal end of the ablation catheter; the outlet of the perfusion cavity can be one or more, and can be set according to the actual requirement. When the perfusion liquid is physiological saline, the perfusion liquid can assist in taking away the redundant heat generated by the electrode to cool the electrode, and at the moment, the outlet of the perfusion cavity can be arranged on the side surface of the supporting body close to the electrode so as to better cool the electrode. When the perfusion fluid is a contrast agent, the outlet of the perfusion chamber may also be disposed on the ablation catheter at a position near the ablation assembly, and preferably, the outlet of the perfusion chamber may be disposed on the ablation catheter at a position 513 mm to 10 mm from the proximal end of the ablation assembly, so as to display the position of the ablation assembly in the blood vessel with less contrast agent.

It will be appreciated that the surface of the ablation catheter in the above embodiments may be provided with a hydrophilic coating to reduce friction between the ablation catheter and the vessel wall. In order to make the hydrophilic coating work well, the hydrophilic coating is arranged on at least one section of the catheter main body of the ablation catheter, which is close to the ablation assembly. Preferably, the proximal end of the hydrophilic coating is greater than or equal to 15 millimeters in axial length along the catheter body to the proximal end of the ablation assembly.

The above-mentioned embodiments only express several embodiments of the present invention, and the description thereof is more specific and detailed, but not construed as limiting the scope of the present invention. It should be noted that, for a person skilled in the art, several variations and modifications can be made without departing from the inventive concept, which falls within the scope of the present invention. Therefore, the protection scope of the present patent shall be subject to the appended claims.

Claims

1. An ablation catheter comprises a radially incompressible support body and at least one electrode arranged on the surface of the support body, wherein the support body comprises a truncated cone, the support body comprises a distal end cross section and a first cross section, the cross section of the support body corresponding to the distal end of the electrode, which is closest to the distal end of the support body, in the at least one electrode is the first cross section, and the radial maximum length of any cross section between the distal end cross section and the first cross section of the support body is smaller than the radial maximum length of the first cross section;

the side of the supporting body is provided with a groove, the groove extends along the axial direction of the supporting body, and the electrode is erected on the groove.

2. The ablation catheter of claim 1, wherein a width of the groove along a circumferential direction of the support side increases gradually from a distal end to a proximal end.

3. The ablation catheter of claim 1, wherein the grooves have a width that is equal from a distal end to a proximal end along a circumferential direction of the side surface of the support body, the electrodes are linear electrodes that are provided on the side surface of the support body, and the linear electrodes are parallel to an axial direction of the support body.

4. The ablation catheter of claim 1, wherein the support body further has a second cross section between the first cross section and the proximal cross section thereof, the cross section of the support body corresponding to the proximal end of the electrode closest to the proximal end of the support body among the at least one electrode is the second cross section, and the maximum radial length of the second cross section is less than or equal to the maximum radial length of the proximal cross section.

5. The ablation catheter of claim 4, wherein the support body has a first cross-section with a maximum radial length of less than or equal to 1.1 mm, a second cross-section with a maximum radial length of greater than or equal to 2.5 mm and less than or equal to 3.5 mm, and a distance between the first cross-section and the second cross-section of greater than or equal to 4 mm and less than or equal to 7 mm.

6. The ablation catheter of claim 4, wherein the support body has a first cross-section with a maximum radial length of less than or equal to 0.9 mm, a second cross-section with a maximum radial length of greater than or equal to 2 mm and less than or equal to 2.5 mm, and a distance between the first cross-section and the second cross-section of greater than or equal to 3 mm and less than or equal to 6 mm.

7. The ablation catheter of claim 4, wherein the support body has a first cross-section with a maximum radial length of less than or equal to 2.5 mm, a second cross-section with a maximum radial length of greater than or equal to 5mm and less than or equal to 8 mm, and a distance between the first cross-section and the second cross-section of greater than or equal to 4 mm and less than or equal to 12 mm.

8. The ablation catheter of claim 4, wherein the support body has a first cross-section with a maximum radial length of less than or equal to 1 mm, a second cross-section with a maximum radial length of greater than or equal to 2.5 mm and less than or equal to 3.5 mm, and a distance between the first cross-section and the second cross-section of greater than or equal to 4 mm and less than or equal to 7 mm.

9. An ablation catheter comprises a support body which is not compressible in the radial direction and at least one electrode arranged on the surface of the support body,

the supporting body comprises a plurality of supporting subunits and at least one flexible connecting part, two adjacent supporting subunits in the plurality of supporting subunits are connected through the flexible connecting part, the electrode is an annular electrode, and the annular electrode is sleeved on the peripheral surface of the supporting subunits;

the support body comprises a far end cross section and a first cross section, the cross section of a support subunit corresponding to the far end of the electrode closest to the far end of the support body in the at least one electrode is the first cross section, and the radial maximum length of any cross section between the far end cross section of the support body and the first cross section is smaller than the radial maximum length of the first cross section.