CN110974403A - Radio frequency ablation catheter for pulmonary nerve ablation - Google Patents

Abstract

The application discloses a radio frequency ablation catheter for implementing pulmonary nerve ablation, which comprises a core tube assembly and a plurality of electrodes arranged on the core tube assembly, wherein the core tube assembly comprises a core tube and an expansion part connected to the far end of the core tube; the expansion part is in a three-dimensional net cage shape in an expansion state and comprises a plurality of solid elastic rods, one ends of the elastic rods are connected in a gathering mode, and the other ends of the elastic rods are fixedly inserted at the far end of the core pipe. The technical scheme that this application is disclosed has realized that the breathing pipeline of core pipe subassembly to different positions, form can both realize stable, convenient, accurate ablation operation through the setting of inflation portion, has improved the efficiency of operation and the effect of treatment.

Description

Radio frequency ablation catheter for pulmonary nerve ablation

Technical Field

The present application relates to the field of interventional therapy, and in particular to a radio frequency ablation catheter for pulmonary nerve ablation.

Background

Chronic Obstructive Pulmonary Disease (COPD) is the most common Disease of the respiratory system, and has been shown in our country to be around 10% in adults over 40 years of age, based on current epidemiological survey evidence.

Currently, COPD mainly depends on drug therapy, and most of the drugs are anticholinergic drugs for specific blocking of M receptors, which causes relaxation of airway smooth muscle, airway relaxation and reduction of mucus secretion, thereby alleviating airway obstruction and relieving symptoms of COPD patients, while ablation of pulmonary denervation Therapy (TLD) pulmonary denervation therapy aims at parasympathetic nerves, blocks the dominant action thereof, and achieves permanent anticholinergic action. This approach has completed a feasible clinical study in 2015, and further clinical trials are currently underway.

With the continuous improvement of society on COPD and the continuous development of interventional technology, the treatment of chronic obstructive pulmonary disease through airway interventional technology has gained various recognition, and TLD as one of the treatment methods has the advantages of more thorough and more efficient treatment compared with the drug treatment. Therefore, the development of the TLD ablation catheter and the matched equipment thereof is planned to provide technical support for a new method for treating the chronic obstructive pulmonary disease.

As a new trend in recent years to treat COPD, TLD ablation is required to ablate the parasympathetic nerves around the main bronchi, block their innervation, achieve permanent anticholinergic effects, reduce airway smooth muscle tone, reduce mucus secretion, and improve clinical symptoms of chronic obstructive pulmonary disease.

In the ablation process, the inner wall of the main bronchus needs to be ablated in a ring shape, and an ablation point forms a closed ring on the inner wall of the main bronchus, so that effective blocking can be performed.

The inventor finds that most of the ring-shaped catheters in the related technology are electrophysiology mapping catheters, and most of the ablation catheters are single-pole ablation catheters, so that multiple ablations are needed in the treatment process, and the ablations form a closed ring, so that the operation process is complicated, and the treatment effect is not easy to control. The ablation degree is insufficient, and the ablation points are not easy to form a closed ring and are difficult to effectively block; the degree of ablation is excessive, the injury is too large, and the recovery process of the patient is not favorable.

Meanwhile, the inner pipe diameter of the breathing pipeline can be gradually reduced along with the deep intervention, the form of the ablation electrode in the related technology is relatively determined, the adaptability to different arranged target tissues is poor, the ablation position is easily too high, excessive nerve inactivation is caused, and the influence on a patient is large.

Disclosure of Invention

In order to solve the above problems, the present application discloses a radiofrequency ablation catheter for performing pulmonary nerve ablation, comprising a core tube assembly and a plurality of electrodes mounted on the core tube assembly, wherein the core tube assembly comprises a core tube and an expansion part connected to the distal end of the core tube; the expansion part in an expansion state is in a three-dimensional net cage shape, the expansion part comprises a plurality of solid elastic rods, one ends of the elastic rods are connected in a gathering mode, and the other ends of the elastic rods are fixedly inserted at the far end of the core pipe;

each electrode is fixed on a corresponding elastic rod, a cooling medium flow channel is respectively arranged in each electrode, and an output port communicated with the cooling medium flow channel is arranged on the outer surface of each electrode;

and a plurality of conveying pipes penetrate through the core pipe, one end of each conveying pipe is used for connecting a cooling medium conveying device, and the other end of each conveying pipe extends out of the core pipe and then extends along the corresponding elastic rod until the conveying pipe is butted with a cooling medium flow passage of the electrode on the elastic rod.

Several alternatives are provided below, but not as an additional limitation to the above general solution, but merely as a further addition or preference, each alternative being combinable individually for the above general solution or among several alternatives without technical or logical contradictions.

Optionally, each elastic rod is pre-shaped in a radially folded state, a distal end of each elastic rod is directly or indirectly connected with a pull core, and the pull core extends towards a proximal end to pull the elastic rod to deform so as to enter an expanded state.

Optionally, each elastic rod is pre-shaped to be in a radially expanded state, and the manner of each elastic rod entering the expanded state is as follows:

the expansion state is entered by the elasticity of the self body; or

The far end of each elastic rod is directly or indirectly connected with a pulling core, and the pulling core extends towards the near end and is used for pulling the elastic rods to deform so as to enter an expansion state.

Optionally, in the expanded state, in the axial direction of the core tube, two ends of the expansion part are closed, and the middle part of the expansion part is expanded to form a working area; the electrodes are mounted on the outer peripheral surface of the working area.

Optionally, the expansion part includes a plurality of elastic rods, one end of each elastic rod is connected in a gathering manner, the other end of each elastic rod is fixedly inserted into the distal end of the core tube, and each electrode is fixed on one corresponding elastic rod.

Optionally, in a loading state opposite to the expansion state, the elastic rods are mutually parallel and are contracted in the sheath tube; under the expansion state, each elastic rod is arc-shaped or wave-shaped; the electrodes are arranged at the arc top part or the wave crest part of the corresponding elastic rod.

Optionally, one end of each of the elastic rods is connected to a connector, and the elastic rods are radially distributed with the connector as a center in an expanded state; the connector includes:

the far ends of the elastic rods are gathered together and attached to the periphery of the central block;

a fastening cap member that fastens and fixes the plurality of elastic rods together with the center block;

the central block is provided with an adaptive structure for connecting a pull core, and the pull core is used for drawing and changing the posture of the expansion part.

Optionally, the pull core is of a solid structure;

or the drawing core is a hollow structure, and an auxiliary cooling medium passage is formed in the drawing core.

Optionally, a plurality of conveying pipes are arranged in the core pipe in a penetrating manner to form the conveying channels respectively, and each conveying channel supplies a cooling medium to one of the electrodes; each conveying pipe is a pipe body which is independently configured or the core pipe is provided with a plurality of cavities, and each conveying pipe is provided by one cavity.

Optionally, each electrode is provided with a cooling medium channel and is in butt joint with a corresponding conveying pipe, and the output port is provided on the outer surface of each electrode and is communicated with the cooling medium channel inside the electrode; the distal portion of the tube extends beyond the core tube and then along the respective flexible rod until it abuts the electrode on the flexible rod.

Optionally, a sleeve is arranged on the elastic rod, and a distal end portion of the delivery pipe extends out of the core pipe and then extends into the sleeve to reach the electrode; a plurality of output ports on each electrode are arranged and have different directions; the elastic rod is provided with a sleeve, the electrode is connected with a first lead, and the first lead extends into the core tube through the inside of the sleeve and extends towards the near end.

Optionally, a plurality of wetting holes communicated with the output port are distributed on the electrode, and the cooling medium from the output port is distributed to the periphery of the electrode through the wetting holes.

This application has realized through the setting of inflation portion that core pipe subassembly can both realize stable, convenient, accurate the operation of melting to different positions, the breathing pipe of form, has improved the efficiency of operation and the effect of treatment.

Specific advantageous effects will be explained in the detailed description in conjunction with specific examples.

Drawings

FIG. 1 is a schematic view of an exemplary RF ablation catheter;

FIGS. 2 a-2 b are schematic views of an expansion portion in an embodiment;

fig. 3a and 3b are schematic views illustrating the installation of the connector;

FIGS. 4a to 4f are schematic views of cooling medium passages in the second embodiment;

FIG. 5 is a schematic view of the wetting holes on the electrode.

The reference numerals in the figures are illustrated as follows:

1. a core tube assembly; 11. an expansion part; 111. an elastic rod; 1111. a cavity; 112. a connector; 1121. a center block; 1122. a fastening cap; 1123. an adaptation structure; 13. a delivery channel; 131. an output port; 132. a sleeve;

2. an electrode; 21. a socket is butted; 211. an annular projection; 22. an electrode card slot;

4. core pulling;

51. and (6) infiltrating the holes.

Detailed Description

The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are only a part of the embodiments of the present application, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

It will be understood that when an element is referred to as being "connected" to another element, it can be directly connected to the other element or intervening elements may also be present. When a component is referred to as being "disposed on" another component, it can be directly on the other component or intervening components may also be present.

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 application belongs. The terminology used in the description of the present application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application. As used herein, the term "and/or" includes any and all combinations of one or more of the associated listed items.

In the embodiment of fig. 1, the present embodiment discloses a radiofrequency ablation catheter for performing pulmonary nerve ablation, comprising a core tube assembly 1 and a plurality of electrodes 2 mounted on the core tube assembly 1,

the distal end of the core tube assembly 1 is provided with an expansion part 11, and a plurality of electrodes 2 are arranged on the expansion part 11 at intervals;

a delivery channel 13 is further provided in the interior of the core tube assembly 1, one end of the delivery channel 13 is used for connecting a cooling medium delivery device, and the other end extends to the expansion part 11 and is provided with an output port 131 for each electrode 2.

The rf ablation catheter in this embodiment is entered through the bronchoscope through the airway to the target site. The respiratory tract has larger difference compared with other interventional paths, and the pipe diameters of other interventional paths have less change degree; and the tube diameter of the respiratory tract changes to a greater extent. Therefore, the radiofrequency ablation catheter realizes treatment of different target positions through the core tube assembly 1 provided with the expansion part 11. The expansion part 11 can change the volume of the expansion part, so that the electrode 2 arranged on the expansion part 11 is prevented from approaching the target position and is matched with respiratory tracts with different pipe diameters.

During ablation, a cooling medium needs to be delivered. The cooling medium can prevent the target tissue from being over-heated in the ablation process to influence the treatment effect. In the embodiment, the output ports 131 are designed independently for the plurality of electrodes 2, so that the ablation parameters of the plurality of electrodes 2 can be controlled independently. The electrodes 2 are provided with independent output ports 131, so that a structural basis can be provided for independently controlling ablation parameters by the single electrode 2, and better ablation effect can be achieved.

Whether the electrode 2 can approach the target point in an appropriate posture depends on the deformed posture of the expansion portion 11. In the embodiment shown with reference to fig. 2a, the core tube assembly 1 comprises a core tube and an expansion 11;

the core tube has opposite distal and proximal ends, the expansion portion 11 is connected to the distal end of the core tube, and the expansion portion 11 in an expanded state is a three-dimensional netpen shape.

The expansion part 11 has different specifications in the expanded state and the loaded state. When the expansion part 11 is in the loading state, a smaller volume and higher flexibility are required to facilitate intervention operation of medical staff and other operators; when the expansion part 11 is in an expansion state, a larger deformation amount is needed to ensure that the expansion part can be attached to target positions with different inner diameter sizes; when the expansion part 11 enters the expansion state from the installation state, the deformation of the expansion part 11 needs to be controlled linearly, so that the operation of operators such as medical staff is facilitated. In view of the above requirements, the expansion part 11 in this embodiment is preferably in a three-dimensional netpen shape, and the netpen-shaped expansion part 11 can ensure a smaller volume and higher flexibility in a loading state, a larger volume in an expansion state and controllability of a deformation process. The solid mesh cage may be, for example, a sphere, an ellipsoid, a cylinder, etc., but it is required that the geometric shape thereof is very regular and is only a rough shape characteristic, and the density of the mesh cage is not strictly limited.

In one embodiment, the expansion part 11 includes a plurality of solid elastic rods 111, one end of each of the plurality of elastic rods 111 is connected in a converging manner, and the other end is fixedly inserted into a distal portion of the core tube.

The expansion part 11 has elasticity by the elastic rod 111 itself, but the direction of the elasticity can be optimally selected.

For example, in one embodiment, each of the flexible rods 111 is pre-configured to a radially expanded state, and each of the flexible rods 111 is brought into an expanded state by:

the expansion state is entered by the elasticity of the self body; or

The distal end of each elastic rod 111 is directly or indirectly connected with a pull core 4, and the pull core 4 extends towards the proximal end for drawing the elastic rod 111 to deform to enter the expansion state.

The elastic force of the elastic rod 111 can drive the expansion part 11 to enter an expansion state, that is, the expansion part 11 is in an expansion state of radial expansion when no external force is applied, and the expansion part can be generally wrapped and furled by matching with a sheath tube (not shown) sliding relative to the core tube during loading, so as to limit the expansion part 11 in the loading state. At this time, the pull core 4 can be omitted, and the pull core 4 can be matched, so that the posture of the expansion part can be accurately regulated and controlled.

In another embodiment, for example, each of the elastic rods 111 is pre-configured in a radially collapsed state, and a pull core 4 is directly or indirectly attached to a distal end of each of the elastic rods 111, the pull core 4 extending proximally for pulling the elastic rods to deform to enter an expanded state.

The expansion part 11 is in a loading state of being radially folded when no external force is applied, and at this time, the pull core 4 is used in cooperation, and the expansion part is driven to enter an expansion state by the pull core 4.

The elastic bars 111 do not affect the arrangement of the electrodes in the different states of the pre-shaping and are therefore not separately distinguishable below.

In the specific arrangement of the electrode 2, with reference to the embodiment shown in fig. 2b, the electrode 2 is arranged on the outer circumferential surface of the expansion part 11.

The outer peripheral surface of the expansion part 11 is the most easily contacted part with the inner wall of the respiratory tract, and the electrode 2 arranged on the outer periphery of the expansion part 11 can conveniently realize the ablation operation of the target tissue. More importantly, the expansion part 11 can be provided with various shapes so as to adapt to different internal tube diameters and shapes of respiratory tracts. On the basis, an electrode can be further arranged on the end face of the far end of the expansion part 11 so as to adapt to the ablation requirement of a specific part.

In the specific arrangement of the expansion part 11, referring to the embodiment shown in fig. 3a to 3b, in the expansion state, in the axial direction of the core tube, both ends of the expansion part 11 are closed, and the middle part is expanded to form a working area; the electrode 2 is mounted on the outer peripheral surface of the working area.

The expansion part 11 can control the expansion degree of the middle part through the distance between the two ends, so that the expansion part is linearly controlled, and the deformation process of the expansion part 11 is accurately controlled by operating personnel such as medical personnel. The electrode 2 is arranged on the peripheral surface of the working area, and the working area is used as the part with the largest volume of the expansion part 11 in the expansion state, so that the electrode can be better attached to the inner wall of the respiratory tract, and the ablation operation can be conveniently realized.

In the embodiment disclosed with reference to fig. 2a, the expansion part 11 comprises a plurality of elastic rods 111, one end of each of the plurality of elastic rods 111 is connected in a converging manner, the other end is fixedly inserted into a distal portion of the core tube, and each of the electrodes 2 is fixed to a corresponding one of the elastic rods 111.

The elastic rod 111 provides a driving force for deformation of the expansion part 11. Since the member directly driving the expansion part 11 to deform has the largest stress among the members, the electrode 2 is provided on the elastic rod 111 to secure the position of the electrode 2 in the respiratory tract, and the success rate of the intervention is increased, thereby improving the treatment efficiency. In other embodiments, a plurality of electrodes may be disposed on the same elastic rod, and the cross-sectional shape of the elastic rod 11 is not limited, and may be circular, rectangular, or elliptical, and the elastic rod 11 itself is a solid structure. For a certain elastic rod 11, a single rod body can be used, and a form of multi-strand twisting, or a form of combining a core wire with a spiral coating, etc. can also be used. The near-end of many elastic rods 111 gathers and fixed the grafting at the distal end position of core pipe, and the distal end position of core pipe can adopt elasticity to hoop tightly, and mode such as welding is fixed with the near-end constraint of many elastic rods 111, for the ease of parts such as threading wire, can set up a central support piece, and the near-end of many elastic rods 111 gathers and draws close in this central support piece's periphery, and sets up the hole of dodging that is used for parts such as threading wire on this central support piece.

During the interventional and ablation procedures, the shape of the expansion 11 changes. In the loading state, the elastic rods 111 are mutually parallel and contracted; in the expanded state, each elastic rod is arc-shaped.

The elastic rods 111 bundled in parallel can provide smaller volume, and facilitate the implementation of the interventional procedure. Meanwhile, the parallel converging state reduces the deformation stress of the expansion part 11 in the road entering process, and the operation is convenient. The arc-shaped elastic rod can ensure that sharp appearance cannot be formed in the process of intervening in the human body, and unnecessary injury is avoided.

In the loaded state, the resilient rods extend substantially linearly and have a smaller overall outer diameter after collapse to provide passability.

At the specific arrangement position of the electrode 2, the electrode 2 is arranged at the arc top part of the corresponding elastic rod 111.

The arc top portion is a portion where the amount of deformation of the elastic rod 111 is the largest. Electrode 2 installs and can change the deformation of inflation portion 11 into the change of electrode 2 relative position completely at the arc top position, consequently changeable respiratory tract of adaptation that can be better to satisfy complicated treatment demand. Under the inflation state, each elastic rod is the arc, can also understand the wavy structure that multistage arc concatenation formed, and the arc top position is probably more than a department, for example 2 ~ 3 departments in crest position, when setting up a plurality of electrodes on same elastic rod, each electrode sets up respectively in corresponding crest department.

In the spatial arrangement of the elastic rods 111, referring to fig. 3a, one end of each of the elastic rods 111 is connected to a connector 112, and in the expanded state, the elastic rods are radially distributed around the connector 112.

The relative distance between the connector 112 and the distal end of the core tube controls the degree of deformation of the elastic member, and thus the degree of deformation of the expansion 11. Many elastic rods 111 are connected to connector 112, just can realize connector 112 to many elastic rods 111's synchro control, make things convenient for operating personnel such as medical personnel accurate and convenient control inflation portion 11 state in the human body, accurate realization melts the process. The elastic rod 111 with radiation distribution distributes the electrode 2 to the inner wall of the respiratory tract by taking the core tube as the center, thereby conveniently and accurately realizing the annular ablation of the target point.

In the arrangement of the connection head 112, in the embodiment disclosed with reference to fig. 3b, the connection head 112 comprises:

a central block 1121, wherein the distal ends of the elastic rods 111 are gathered together and abut against the periphery of the central block 1121;

and a fastening cap 1122, wherein the fastening cap 1122 fastens and fixes the plurality of elastic rods 111 together with the central block 1121.

Through the setting of fastening cap 1122, the installation and the location of realization elastic rod 111 that can be convenient and firm reduce the requirement of production precision, improve production efficiency, reduction in production cost. The central block 1121, which is a biasing member for applying a biasing force to the elastic rod 111 to drive the elastic rod 111 to deform, can apply the same biasing force to the elastic rods 111 synchronously and equally, and facilitates control of the deformation process of the expansion portion 11 by an operator such as a medical worker.

Correspondingly, in the embodiment disclosed with reference to fig. 3b, the central block 1121 is provided with an adapting structure 1123 for connecting the pull core 4, and the pull core 4 is used for traction to change the posture of the expansion part 11.

The pull core 4 is used to drive the relative distance between the central block 1121 and the distal portion of the core tube, thereby applying a force to the elastic rod 111 to drive the elastic rod 111 to deform. The adaptive structure is disposed at a proximal side of the central block 1121, and is fixed to the central block 1121 in an integrated or separated manner, specifically, the adaptive structure may be a connecting hole, a hook, or the like, and a distal end of the pull core 4 may be inserted into and welded to the connecting hole, or tied and fixed to the hook.

In various embodiments, the pull core 4 has a solid structure or a hollow structure.

In the hollow structure, an auxiliary cooling medium passage is formed inside the core 4, and a cooling medium (e.g., physiological saline) can be introduced to form auxiliary cooling.

In a preferred embodiment, the central block 1121 may be provided with an opening connected to the auxiliary cooling medium passage for directly outputting the cooling medium, and a valve structure may be provided in the central block 1121 to control the on/off state of the auxiliary cooling medium passage.

The auxiliary cooling medium passage inside the core 4 also forms a loop for implementing the cooling by means of a circulating cooling medium, which may or may not be via the central block 1121.

In a specific arrangement, in the embodiment disclosed with reference to fig. 4a, the number of the plurality of resilient bars 111 is 4.

The more the number of the elastic rods 111 is, the more the positions of the electrodes 2 can be correspondingly arranged, so that the annular ablation on the target point can be realized more conveniently, but the difficulty of bending the distal end of the core tube in the interventional process is increased by increasing the number of the elastic rods 111, and 3 or 4 elastic rods are preferred.

The elastic rod 111 is a solid rod, which can reduce the volume as much as possible under the same mechanical parameters, thereby providing better intervention effect.

In one embodiment, the elastic rods 111 are made of nitinol, and the elastic rods 111 are insulated from the electrode 2 by plating an insulating layer or wrapping an insulating tube.

The nickel-titanium alloy is convenient to perform, can be conveniently unfolded to a preset shape in a human body, and is convenient for operation of operators such as medical staff; the respiratory tract has changeable and complex shape, except the electrode 2 can contact with the inner wall of the respiratory tract, the elastic rod 111 can also contact with the inner wall of the respiratory tract, and therefore, the elastic rod 111 and the electrode 2 need to be arranged in an insulating way to avoid the damage to normal tissues.

In the embodiment disclosed with reference to fig. 4d, the electrode 2 is provided with an electrode slot 22 and is fixed to the corresponding elastic rod 111 by the slot.

The electrode 2 may be adhered to the tissue of the target point during the ablation operation, and a certain connection strength needs to be maintained between the electrode 2 and the elastic rod 111 when the core tube is moved, so that the electrode clamping groove 22 is preferably designed, and the stress performance of the electrode 2 in all directions can be improved structurally. The electrode clamping groove 22 can also prevent the electrode 2 from rotating around the elastic rod 111, so as to avoid unnecessary dislocation, in order to ensure the effect of preventing rotation and dislocation, at least a part of the matching part of the electrode clamping groove 22 and the elastic rod 111 is a plane in the preferred embodiment, and in addition, a positioning bulge and other structures can be arranged in the length direction of the elastic rod 111 to limit the slippage of the electrode 2.

The core tube is used for transporting the electrode 2 and also for transporting a cooling medium to the vicinity of the target point. The cooling medium can cool the tissues near the target point when the electrode 2 works, and the ablation effect is improved. In one embodiment, a plurality of ducts are formed through the core tube to form the respective ducts 13, each duct 13 supplying one of the electrodes 2 with a cooling medium. The plurality of conveying pipelines can ensure the flow of the cooling medium when the plurality of electrodes 2 carry out ablation operation, and ensure the ablation effect. In one embodiment, each delivery line flow is independently controlled.

In some usage scenarios, the ablation parameters of each electrode 2 may need to be controlled independently, and the need for a cooling medium may also be inconsistent. The embodiment realizes accurate control of the cooling medium by independently controlling the flow of the delivery pipe. The regulation and control precision and the adaptability of the radiofrequency ablation catheter for implementing the pulmonary nerve ablation are improved, and the good ablation effect can be realized on target spots in different positions and under different conditions.

The independent control can be implemented in the prior art, for example by configuring the delivery pump and the corresponding control circuit separately for each delivery channel.

In one embodiment, each delivery tube is a separately configured tube or core tube with its own plurality of channels, each delivery tube being provided by one of the channels.

The arrangement of the conveying pipe also has various advantages. For example, the design scheme of independent configuration can provide larger flow, and is suitable for use scenes with larger pipe diameter and higher requirement on the flow of the cooling medium; and for example, a design scheme that the core tube is provided with a plurality of cavities can provide a more regular external shape, so that the interventional process can be conveniently realized in a narrow respiratory tract. The specific selection can be matched with other design schemes according to the requirements of the use scene.

When a plurality of cavities are adopted, the core tube can be integrally formed during processing, for example, a die head with a corresponding structure is adopted for extrusion molding, and the like.

The cooling medium needs to spread to function at the site where the electrode 2 achieves ablation. In the embodiment shown in fig. 4a to 4c, when the cooling medium is matched with the electrodes 2, each electrode 2 is provided with a cooling medium channel and is in butt joint with a corresponding conveying pipe, and the output port 131 is provided on the outer surface of each electrode 2 and is communicated with the cooling medium channel inside the electrode 2.

The cooling medium directly diffuses from the electrode 2 to the target position, so that the cooling medium can be ensured to be synchronous with the position where ablation occurs, and the action effect of the cooling medium is improved. Meanwhile, the cooling medium flows through the electrode 2, so that the temperature difference between the tissues near the target point and the electrode 2 can be reduced, and the implementation of ablation parameter control means such as temperature control and the like is facilitated. In a practical application scenario, the cooling medium is generally conductive normal saline, and the normal saline diffused from the electrode 2 can also improve the ablation effect and optimize the ablation operation environment.

In a particular arrangement, in the embodiment disclosed with reference to figure 4a, the distal portion of the tube extends beyond the core tube and along the respective flexible rod 111 until it abuts the electrode 2 on the flexible rod 111.

The conveying pipe is arranged along the elastic rod 111 and can better adapt to the deformation of the expansion part 11. Meanwhile, the elastic rod 111 is a force application member for driving the expansion part 11 to deform, so that the conveying pipe can be prevented from being deformed in a blocking manner under the action of external force, and the cooling medium can be stably conveyed to the electrode 2.

Reference is made to fig. 4d to 4f for an embodiment shown, where fig. 4e is a side sectional view of fig. 4d and fig. 4f is a top sectional view of fig. 4 d. The electrode 2 is provided with a butt joint socket 21 connected with the conveying pipe, the butt joint socket 21 is a tubular structure which can be integrated with the electrode or a split fixing structure, the butt joint socket 21 is provided with an annular bulge 211 for preventing the conveying pipe from dropping off, the inside of the electrode 2 forms a structure similar to a tee joint, and a cooling medium from the butt joint socket 21 is diffused to an ablation part through an output port 131 on the electrode 2.

In another embodiment, in order to facilitate the butt joint of each electrode 2 and the conveying pipe, the electrode 2 may be provided with a slot, the slot is communicated with a cooling medium flow passage inside the motor, and the end part of the conveying pipe is fixed in the slot. In one embodiment, the flexible rod 111 is provided with a sleeve 132, and the distal portion of the delivery tube extends out of the core tube and into the sleeve 132 to the electrode 2.

To prevent tissue within the airway from affecting the delivery tube, the cannula 132 can form a relatively closed environment. Meanwhile, the sleeve 132 can also function as an insulating layer to prevent the RF energy on the electrode 2 from being transmitted to the normal tissue through the elastic rod 111.

In the embodiment disclosed with reference to fig. 4d, the output ports 131 on each electrode 2 are multiple and oriented differently.

The electrode 2 can diffuse in multiple directions when ablating the tissue of the target point, so the cooling medium needs to diffuse in multiple directions to ensure the ablation is orderly carried out. Therefore, the present embodiment realizes the diffusion of the cooling medium in different directions by setting the output ports 131 to have different orientations, and ensures the coverage area of the cooling medium. When the number of the output ports 131 on the electrode 2 is plural, the cooling medium flow passage inside the electrode 2 may adopt a branch structure, one end of each branch is linked with the delivery pipe, and the other end is communicated to the corresponding output port 131.

The electrode 2 requires proximal delivery of radio frequency energy during ablation. Wires need to be arranged on the core tube. In one embodiment, the flexible rod 111 is provided with a sleeve 132, and the electrode 2 is connected with a first lead wire extending through the interior of the sleeve 132 into the core and extending proximally.

The lead is protected by the sleeve 132 so as to avoid friction with the respiratory tract affecting the stability of the lead, which is important in the interventional field and often directly affects the efficacy of the treatment and the efficiency of the procedure. The sleeve 132 may preferably be a PTFE shrink tube in material.

During the ablation procedure, the ablation status of the electrode 2 and the extent of ablation need to be controlled by a number of parameters. In one embodiment, the radiofrequency ablation catheter further comprises a plurality of temperature sensors, each temperature sensor being applied against or embedded in a respective electrode 2.

The temperature is a parameter which is easier to observe in the ablation operation and is directly related to the ablation process, and the ablation degree and the process can be directly controlled through the temperature sensor. The temperature sensor is attached to or embedded in the electrode 2, so that the ablation state of the electrode 2 can be detected more accurately. Meanwhile, the electrodes 2 are provided with temperature sensors independently, and a structural basis is provided for independently controlling the ablation parameters of the electrodes 2.

In one embodiment, a sleeve 132 is disposed on each flexible rod 111, a second wire is connected to each sensor, and each second wire extends into the core tube through the interior of the sleeve 132 and then extends proximally.

The second wire is protected by the sleeve 132, so that the influence of friction between the second wire and the respiratory tract on the stability of the second wire is avoided, the stability of reading of the temperature sensor is ensured, and the precision of ablation control is improved. The sleeve 132 may preferably be a PTFE shrink tube in material. In connection with the previous embodiments, the first and second wires may be encased within the same sleeve 132.

In addition to natural diffusion of the cooling medium when it is diffused to the target, the infiltration holes 51 may be designed to enhance the diffusion effect. Referring to fig. 5, in the embodiment, a plurality of wetting holes 51 communicated with the output ports 131 are distributed on the electrode 2, and the cooling medium from the output ports 131 is distributed to the periphery of the electrode 2 through the wetting holes 51.

The infiltration holes 51 can better diffuse the cooling medium to the target point, especially between the contact surface of the electrode 2 and the target point, thereby optimizing the ablation effect and facilitating the control of the ablation process. A plurality of fine infiltration holes 51 are uniformly distributed on the electrode 2. The cooling medium enters the inner pore passage of the electrode 2 from the conveying pipe and flows out from the infiltration holes 51, and a thin cooling medium film in a water film form is formed on the outer surface of the electrode 2, so that the surface of the electrode is infiltrated by the cooling medium (in the embodiment, the cooling medium is physiological saline), ablation tissue scabbing is further avoided, and loop impedance is reduced. Maintaining impedance balance allows the ablation process to continue until the target ablation volume is reached.

The pore size and density distribution of the wetting holes 51 can be set according to the flow demand of the heat exchange medium, so as to ensure that a uniform protective film is formed on the periphery of the electrode as much as possible, for example, all the wetting holes 51 have the same pore size, or are set according to the flow balance of the heat exchange medium.

I.e., the size of the wetting holes 51 in different areas can be varied to accommodate the need for uniform flow. In the same way, the distribution density of all the infiltrating holes 51 at different parts of the electrode 2 is the same, or the infiltrating holes are correspondingly arranged according to the flow balance of the heat exchange medium.

When the heat exchange medium flow rate is balanced and correspondingly set, the arrangement mode of the heat exchange medium flow channel outlet is mainly considered, for example, the aperture of the wetting hole 51 increases with the distance from the outflow hole.

Similarly, for example, the distribution density of the wetting holes 51 increases with distance from the outlet holes.

The wetting holes 51 may be arranged as desired during processing, for example, in one embodiment, the wetting holes 51 are distributed in a plurality of groups along the circumference of the electrode 2.

In one embodiment, the expansion part 11 includes a plurality of elastic rods 111, one end of each of the plurality of elastic rods 111 is connected in a converging manner, the other end of each of the plurality of elastic rods 111 is fixedly inserted into a distal portion of the core tube, and each of the electrodes 2 is fixed to a corresponding one of the plurality of elastic rods 111.

The elastic rod 111 is used as a main structural part of the expansion part 11, the electrode 2 is wrapped on the elastic rod 111, the installation effect of the electrode 2 can be ensured, the situation that the installation fails due to friction with tissues of a respiratory tract in the intervention process is avoided, and the cooling medium can be stably conveyed to a target point.

Specific structure of the electrode 2, in the embodiment disclosed with reference to fig. 5, the electrode 2 is a closed structure in the circumferential direction of the elastic rod 111.

Accordingly, in one embodiment, the electrode 2 is in a non-closed configuration around the circumference of the flexible rod 111. The electrode 2 with the closed structure can ensure a good connection relation with the elastic rod 111, and can provide enough strength in some treatment scenes in which the electrode 2 needs to be in stressed contact with the tissues of the respiratory tract. Therefore, the installation mode of the specific electrode 2 can be selected according to the use scene and the design index.

In view of the passage of the cooling medium, in an embodiment, the outer wall of the electrode 2 is provided with a distribution groove (not shown), and the cooling medium from the output port 131 is supplied to the wetting holes 51 at the periphery of the corresponding electrode 2 through the distribution groove.

In a specific using method, the radiofrequency ablation catheter for performing pulmonary nerve ablation disclosed by the application establishes an interventional passage through a bronchoscope, after the bronchoscope reaches a focus (namely a target point), a sheath tube with a core tube assembly 1 is plugged into the bronchoscope, an adjustable knob is twisted, a pull core 4 is loosened, the expansion part 11 is contracted and gathered to enter a loading state, the core tube assembly 1 is pushed, the expansion part 11 passes through the bronchoscope from the sheath tube, after the expansion part 11 passes through the bronchoscope, the expansion part 11 is observed through the bronchoscope, a handle at the near end is rotated to adjust the position of an electrode 2, after the adjustment is completed, the adjustable knob is rotated, the pull core 4 is pulled, the expansion part 11 is driven to enter the expansion state, the expansion part is expanded and enlarged until the electrode 2 is well attached to the inner wall of a bronchus, then a cooling medium is introduced, cold saline is adopted in the embodiment, then the radiofrequency instrument is opened, and the plurality of electrodes 2 are simultaneously ablated (the cold saline pump is, if the temperature is higher than 60 ℃, the saline flow rate is increased, if the temperature is not higher than 60 ℃, the flow rate is kept unchanged, the saline flow rate is adjusted within the range of 3-15 ml/min), the ablation power range is 3-10W, the ablation time is 60s-120s, the bronchoscope is matched with and pumps out redundant saline in the cavity channel during ablation, after ablation is completed, the pull core 4 is loosened through the adjustable knob, the expansion part 11 naturally enters a loading state by means of the self elasticity of the elastic rod 111, the ablation position is adjusted, the next round of ablation is carried out, and finally a closed loop is formed at the ablation point on the inner wall of the main bronchus. If the ablation point is observed through the bronchoscope and the ablation point is not closed, the expansion part 11 is adjusted to enable one electrode 2 to be in the gap position, and the monopolar ablation is carried out until the ablation point forms a closed loop.

The technical features of the embodiments described above may be arbitrarily combined, and for the sake of brevity, all possible combinations of the technical features in the embodiments described above are not described, but should be considered as being within the scope of the present specification as long as there is no contradiction between the combinations of the technical features. When technical features in different embodiments are represented in the same drawing, it can be seen that the drawing also discloses a combination of the embodiments concerned.

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

Claims (10)

1. The radiofrequency ablation catheter for performing pulmonary nerve ablation comprises a core tube assembly and a plurality of electrodes arranged on the core tube assembly, and is characterized in that the core tube assembly comprises a core tube and an expansion part connected to the distal end of the core tube; the expansion part in an expansion state is in a three-dimensional net cage shape, the expansion part comprises a plurality of solid elastic rods, one ends of the elastic rods are connected in a gathering mode, and the other ends of the elastic rods are fixedly inserted at the far end of the core pipe;

each electrode is fixed on a corresponding elastic rod, a cooling medium flow channel is respectively arranged in each electrode, and an output port communicated with the cooling medium flow channel is arranged on the outer surface of each electrode;

and a plurality of conveying pipes penetrate through the core pipe, one end of each conveying pipe is used for connecting a cooling medium conveying device, and the other end of each conveying pipe extends out of the core pipe and then extends along the corresponding elastic rod until the conveying pipe is butted with a cooling medium flow passage of the electrode on the elastic rod.

2. The rf ablation catheter according to claim 1, wherein each of the flexible rods is pre-configured in a radially collapsed state, and a pull core is directly or indirectly attached to a distal end of each of the flexible rods, the pull core extending proximally for pulling the flexible rods to deform into an expanded state.

3. The rf ablation catheter of claim 1, wherein each flexible shaft is pre-configured to a radially expanded state, and wherein each flexible shaft is brought into an expanded state by:

the expansion state is entered by the elasticity of the self body; or

The far end of each elastic rod is directly or indirectly connected with a pulling core, and the pulling core extends towards the near end and is used for pulling the elastic rods to deform so as to enter an expansion state.

4. The radiofrequency ablation catheter for performing pulmonary nerve ablation according to any one of claims 1 to 3, wherein in an expanded state, in the axial direction of the core tube, two ends of the expansion part are closed, and the middle part is expanded to form a working area; the electrodes are mounted on the outer peripheral surface of the working area.

5. The rf ablation catheter according to claim 4, wherein the flexible rods are constrained within the sheath in parallel with each other in a loaded state as opposed to an expanded state; under the expansion state, each elastic rod is arc-shaped or wave-shaped; the electrodes are arranged at the arc top part or the wave crest part of the corresponding elastic rod.

6. The rf ablation catheter according to claim 1, wherein one end of the plurality of flexible rods is connected to a connector, and is radially distributed around the connector in the expanded state; the connector includes:

the far ends of the elastic rods are gathered together and attached to the periphery of the central block;

a fastening cap member that fastens and fixes the plurality of elastic rods together with the center block;

the central block is provided with an adaptive structure for connecting a pull core, and the pull core is used for drawing and changing the posture of the expansion part.

7. The rf ablation catheter for performing pulmonary nerve ablation of claim 6, wherein the pull core is a solid structure;

or the drawing core is a hollow structure, and an auxiliary cooling medium passage is formed in the drawing core.

8. The rf ablation catheter according to claim 1, wherein a plurality of delivery tubes are formed through the core tube to form the delivery channels, respectively, each delivery channel supplying a cooling medium to one of the electrodes; each conveying pipe is a pipe body which is independently configured or the core pipe is provided with a plurality of cavities, and each conveying pipe is provided by one cavity;

each electrode is provided with a cooling medium flow channel and is butted with a corresponding conveying pipe, and the output port is arranged on the outer surface of each electrode and is communicated with the cooling medium flow channel in the electrode; the distal portion of the tube extends beyond the core tube and then along the respective flexible rod until it abuts the electrode on the flexible rod.

9. The rf ablation catheter according to claim 8, wherein a sleeve is provided on the flexible shaft, and a distal end portion of the delivery tube extends out of the core tube and into the sleeve to the electrode; a plurality of output ports on each electrode are arranged and have different directions;

the elastic rod is provided with a sleeve, the electrode is connected with a first lead, and the first lead extends into the core tube through the inside of the sleeve and extends towards the near end.

10. The rf ablation catheter of claim 1, wherein the electrode has a plurality of infiltration holes distributed thereon and communicating with the delivery outlets, and the cooling medium from the delivery outlets is distributed around the electrode through the infiltration holes.

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