Pulse electric field ablation microcatheter

Abstract

The invention relates to the technical field of cardiac electrophysiology catheters, and aims to provide a pulsed electric field ablation microcatheter which comprises a catheter part and an operation part, the catheter part comprises an anti-injury section, a tail end catheter body, a catheter body transition section and a near-end catheter body, and the top end of the tail end catheter body is welded to the front end of the anti-injury section; the top end of the catheter body transition section is welded to the front end of the tail-end catheter body, the top end of the near-end catheter body is welded to the front end of the catheter body transition section, an electrode is arranged on the tail-end catheter body, a guide wire is inserted into the catheter part, the catheter part comprises an inner layer and an outer layer, and a braid layer is arranged between the inner layer and the outer layer. The microcatheter can be guided by a guide wire to reach a target area along a cardiac blood vessel, and a pulsed electric field is emitted to surrounding target myocardium through a tail end electrode for ablation; the target area is subjected to combined ablation by combining with the endocardium catheter, and finally the requirement for target myocardial transmural injury is met.

Description

Technical Field

[0001] The invention relates to the technical field of cardiac electrophysiological catheters, and in particular to a pulse electric field ablation microcatheter. Background Art

[0002] Ventricular arrhythmias include premature ventricular beats (PVT), ventricular tachycardia (VT), ventricular flutter and ventricular fibrillation (VF). Frequent premature ventricular beats may induce or aggravate heart failure, and sustained VT may lead to hemodynamic compensation, causing symptoms such as palpitations, blackouts, and syncope, and even worsen to ventricular fibrillation and death. A large proportion of patients with ventricular arrhythmias have normal heart structure. Currently, these patients can be treated in the following ways:

[0003] 1. Installing an implantable cardioverter defibrillator (ICD) can effectively stop life-threatening ventricular tachycardia and ventricular fibrillation, but it cannot prevent recurrence. The time of releasing defibrillation energy is uncertain, which will greatly affect the patient's quality of life.

[0004] 2. Catheter ablation from the endocardium can be performed using radiofrequency or cryotherapy. This method can effectively eliminate or reduce the onset of ventricular arrhythmias, but for some special ventricular arrhythmias, the lesions are located in the epicardium or deep in the ventricular septum (such as the left ventricular top and deep ventricular septum). Because the myocardial thickness in these anatomical locations often exceeds 10 mm, traditional transendocardial catheter ablation cannot achieve transmural damage to completely destroy the lesions.

[0005] 3. Chemical ablation: Ablation by injection of anhydrous ethanol can effectively damage the myocardial tissue in the injection area. However, this method is difficult to predict the damage range, and the myocardial tissue in the injection area is indiscriminately ablated, which is prone to more complications.

[0006] The above-mentioned treatment methods all have their defects and cannot fully meet the treatment of ventricular arrhythmias. Among them, the defect of catheter ablation treatment method is that some anatomical positions of the heart cannot be reached, but it does not have the major defects of the other two treatment methods. If there is a special electrophysiological ablation catheter, different from the conventional electrophysiological ablation catheter, it can reach the lesions near the epicardium or deep myocardium (such as the top of the left ventricle and the deep ventricular septum area) from the coronary artery of the heart, and cooperate with the endocardial catheter to perform combined ablation of the target myocardium during the operation, and finally achieve transmural damage to the lesion myocardium, thereby solving the technical problem of transmural ablation of endocardial catheter. The microcatheter has three major innovations: first, the diameter is thin (about 1mm), which can enter smaller blood vessels, especially those located in the ventricular septum of the heart, which is not available in the currently marketed ablation catheters (diameter>2.3mm); second, the inner cavity is hollow design, which is compatible with all common coronary intervention guidewires, and the catheter can be easily operated through the heart vascular route to reach the target area with the assistance of the guidewire; third, the catheter can be used for safer and more effective pulsed electric field ablation.

[0007] Compared with traditional radiofrequency ablation and cryoablation, pulsed electric field ablation has the advantages of high efficiency, tissue selectivity and no heat accumulation. Therefore, pulsed electric field ablation is a good choice for catheter ablation of ventricular arrhythmias. Summary of the invention

[0008] The purpose of the present invention is to provide a guidewire-guided pulsed electric field ablation microcatheter to solve the problems raised in the background technology and facilitate promotion.

[0009] A pulse electric field ablation microcatheter comprises a catheter part and an operating part, wherein the catheter part comprises an anti-damage section, a terminal tube body, a tube body transition section and a proximal tube body, wherein the top end of the terminal tube body is fused to the front end of the anti-damage section, the top end of the tube body transition section is fused to the front end of the terminal tube body, the top end of the proximal tube body is fused to the front end of the tube body transition section, an electrode is arranged on the terminal tube body, a guide wire is inserted in the catheter part, the catheter part comprises an inner layer and an outer layer, and a braided layer is arranged between the inner layer and the outer layer;

[0010] The operating part includes a handle transition section, a handle, a connecting line and a connector. The handle transition section is connected to the proximal tube body. The handle transition section is provided with a handle at one end away from the proximal tube body. A connecting line is provided under the handle. The end of the connecting line away from the handle is connected to the connector.

[0011] The braided layer includes electrode wires and braided wires that are braided with each other, and two ends of the electrode wires are respectively connected to electrodes and connectors.

[0012] Furthermore, the catheter portion adopts a hollow design, with an outer diameter of less than 3F and an inner diameter greater than or equal to 0.36mm.

[0013] Furthermore, the damage-resistant section, the terminal tube body, the tube body transition section and the outer layer of the proximal tube body are made of Pebax or TPU polymer materials, and the hardness thereof gradually decreases from the proximal tube body to the damage-resistant section.

[0014] Furthermore, the number of the electrodes is greater than 2, and the material thereof is preferably platinum-iridium alloy, the electrode length is 1 mm to 3 mm, and the electrode spacing is 1 mm to 5 mm.

[0015] Furthermore, the electrode wire is a coated copper wire, and the coating material is PI or PET.

[0016] Furthermore, the braided wire is made of PET fiber.

[0017] Furthermore, the number of the electrode wires is the same as the number of electrodes.

[0018] Furthermore, the braided layer is heat-fused between the inner layer and the outer layer.

[0019] As an improvement, the beneficial effects of the present invention are:

[0020] 1. The outer diameter of the catheter can be greatly reduced: The outer diameter of conventional intracardiac ablation catheters is usually 6F to 8.5F. After braiding the electrode wire, the outer diameter of the catheter can be reduced to less than 3F, and the number of electrodes will not be reduced. Such a catheter can reach narrow locations that conventional catheters cannot reach, such as through coronary vessels or to the LVS and DVS areas, or from the coronary sinus to the great cardiac vein to the Marshall vein. Used in conjunction with an endocardial ablation catheter, a deeper ablation depth can be achieved.

[0021] 2. The catheter can be made into a hollow design: the inner lumen of the catheter can be used to pass the guide wire, which can help the catheter reach the desired position. The inner lumen of the catheter can also be used for liquid passage to facilitate the surgical process.

[0022] 3. Pulsed electric field ablation: The catheter emits a pulsed electric field through the electrode, and ablation can be performed in a small area without worrying about tissue scabbing or tissue explosion caused by heat. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is an overall diagram of a pulse electric field ablation microcatheter of the present invention;

[0024] Figure 2 A partial view of the front end of a pulse electric field ablation microcatheter of the present invention;

[0025] Figure 3 This is a schematic diagram of the braided layer of the present invention-1;

[0026] Figure 4 This is a schematic diagram of the braided layer of the present invention-2;

[0027] Figure 5 This is a schematic diagram of the braided layer of the present invention-3;

[0028] Figure 6 Schematic diagram of the cooperation between the pulsed electric field ablation microcatheter and the guide wire-1;

[0029] Figure 7 Schematic diagram of pulsed electric field ablation microcatheter and guide wire cooperation-2

[0030] Reference table of reference numerals:

[0031] 101. anti-injury section; 102. terminal tube body; 103. tube body transition section; 104. proximal tube body; 201. handle transition section; 202. handle; 203. connecting wire; 204. connector; 301. electrode; 401. electrode wire; 402. braided wire; 500. guide wire. DETAILED DESCRIPTION

[0032] The specific embodiments of the present invention are further described below in conjunction with the accompanying drawings. The same components are represented by the same reference numerals. It should be noted that the words "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to directions in the accompanying drawings, and the words "inner" and "outer" refer to directions toward or away from the geometric center of a specific component, respectively.

[0033] In order to make the content of the present invention more clearly understood, the technical solutions in the embodiments of the present invention will be described clearly and completely below in conjunction with the accompanying drawings in the embodiments of the present invention, wherein the same components are represented by the same reference numerals.

[0034] This embodiment provides a pulsed electric field ablation microcatheter, such as Figure 1 As shown, the pulse electric field microcatheter is composed of the following components: an anti-damage section 101, an electrode 301, a terminal tube body 102, a tube body transition section 103, a proximal tube body 104, a handle transition section 201, a handle 202, a connecting line 203, and a connector 204. The inner cavity of the catheter adopts a hollow design, which can be used to pass a guide wire 500 or liquid perfusion. The outer diameter of the pulse electric field ablation microcatheter is less than 3F (3F = 1mm), and the inner diameter is greater than or equal to 0.36mm, and can be used in conjunction with a 0.014in guide wire 500. The outer layers of the proximal tube body 104, the tube body transition section 103, and the terminal tube body 102 of the pulse electric field ablation microcatheter are all made of polymer materials and connected by welding. The hardness gradually decreases from the proximal tube body 104 to the anti-damage section 101.

[0035] like Figure 2As shown, the front end anti-damage section 101 of the pulsed electric field microcatheter is connected to the top of the terminal tube body 102 by welding, which is used to protect the blood vessel wall and prevent scratches when the catheter passes through the heart and blood vessels. The anti-damage section 101 is a polymer material with suitable hardness and softness, preferably Pebax or TPU. More than two ring electrodes are arranged on the terminal tube body 102 to collect electrophysiological signals and emit pulsed electric fields, and the material is preferably platinum-iridium alloy. The electrode length is 1mm to 3mm, preferably 2mm. The electrode spacing is 1mm to 5mm, preferably 3mm. The inner tube of the pulsed electric field microcatheter is made of a relatively smooth polymer material, preferably PTFE. A braided layer is arranged between the inner layer and the outer layer of the tube body, which is cross-woven by the electrode wire 401 and the braided wire 402. The electrode wire 401 is a coated copper wire, and its coating plays an insulating role. The coating material is preferably PI or PET. The number of strands of the electrode wire 401 is the same as the number of electrodes, and the two ends of the electrode wire 401 are respectively connected to the electrode 301 and the connector 204. The braided wire 402 is made of PET fiber, which can protect the wire insulation layer and fix the electrode wire 401 when braided with the electrode wire 401, prevent the insulation strength from being reduced due to mutual friction between the electrode wires 401, and improve product reliability. The braided layer is fixed between the inner tube and the outer tube by hot melting in the tube body.

[0036] like Figure 3 , 4 As shown in Figures 5 and 6, according to the number of strands of the electrode wire 401, the electrode wire 401 and the braided wire 402 can be braided together to form a braided layer in a variety of different braiding methods. The braided layer can effectively increase the toughness of the tube body and reduce the change in the hardness of the tube body caused by the blood temperature. At the same time, due to the braided arrangement of the electrode wire 401 and the braided wire 402, the inner cavity can be retained and the wire conduction requirements can be met under the condition of a small tube size, and the braided layer can be retained to increase the toughness of the tube body.

[0037] like Figure 6 , 7 As shown, the pulsed electric field microcatheter can be used in conjunction with a guide wire 500 with a preset bend. The guide wire 500 can shape the pulsed electric field microcatheter into the same shape as the guide wire 500 in the catheter lumen, thereby making the pulsed electric field microcatheter electrode fit better with the vascular pathway, thereby improving the success rate of pulsed electric field ablation. The guide wire 500 can be preset in a variety of shapes, such as a spiral or an arc, and the user can select a guide wire 500 of a suitable shape according to actual conditions.

[0038] Pulsed electric field ablation technology refers to applying a short high voltage to the tissue to generate a local high electric field of hundreds to thousands of volts per centimeter. This local high electric field can cause pores in the cell membrane (electroporation), thereby changing the exchange of substances in the cell membrane (the cell membrane becomes "permeable"). When the pulsed electric field applied outside the membrane reaches a certain threshold, the exchange of substances inside and outside the membrane caused by membrane perforation can lead to cell necrosis or apoptosis, resulting in irreversible damage. Since different tissue cells have different thresholds for irreversible damage caused by voltage penetration, the use of pulsed electric field technology can selectively treat myocardial tissue (relatively low threshold) without affecting other non-target cell tissues (such as nerves, blood cells, etc.). At the same time, due to the extremely short release of energy, the pulse technology will not produce thermal effects, thereby avoiding problems such as tissue scabs and tissue ruptures. Pulsed electric field microcatheters are expected to be used in narrow cardiovascular pathways, where blood flow is usually small. If radiofrequency energy is used in such areas, it is easy to cause heat accumulation, tissue rupture or scabs, and then cause serious complications. Pulsed electric field ablation is very suitable for narrow vascular pathways, without having to worry about the risk of tissue explosion or scab due to heat accumulation.

[0039] The procedure for using pulsed electric field ablation microcatheter in ventricular arrhythmias is as follows:

[0040] Step 1: Vascular puncture, extend the catheter sheath of appropriate size to the coronary sinus or coronary artery, and send the endocardial ablation catheter into the heart from the femoral vein or artery.

[0041] Step 2: Send the matching guide wire of the pulsed electric field microcatheter through the catheter sheath to the expected position deep in the coronary vein or coronary artery;

[0042] Step 3: Send the pulsed electric field ablation microcatheter to the expected ablation position through the guide wire, and send the endocardial ablation catheter to the expected ablation position in the heart cavity;

[0043] Step 4: Use the pulsed electric field ablation microcatheter to release the pulsed electric field to perform pulsed electric field ablation on the myocardium near the epicardium; use the endocardial pulsed electric field ablation catheter to perform pulsed electric field ablation on the myocardium near the endocardium; perform combined ablation inside and outside the myocardium at the lesion site to ultimately achieve transmural ablation requirements.

[0044] Note: The above-mentioned usage method is only for ventricular arrhythmia. The microcatheter of the present invention can also be used in cardiovascular pathways that cannot be reached by other conventional electrophysiological catheters (usually with an outer diameter of 6F to 8.5F), such as the appropriate position of Marshall vein. The catheter electrode can be used for both electrophysiological signal acquisition and pulsed electric field delivery.

[0045] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.

Claims

1. A pulsed electric field ablation microcatheter, comprising a catheter portion and an operating portion, characterized in that: The catheter portion comprises an anti-damage section (101), a terminal tube body (102), a tube body transition section (103) and a proximal tube body (104); the top end of the terminal tube body (102) is fused to the front end of the anti-damage section (101); the top end of the tube body transition section (103) is fused to the front end of the terminal tube body (102); the top end of the proximal tube body (104) is fused to the front end of the tube body transition section (103); an electrode (301) is provided on the terminal tube body (102); a guide wire (500) is inserted into the catheter portion; the catheter portion comprises an inner layer and an outer layer; a braided layer is provided between the inner layer and the outer layer; The operating portion comprises a handle transition section (201), a handle (202), a connecting line (203) and a connector (204); the handle transition section (201) is connected to the proximal tube body (104); the handle (202) is provided at one end of the handle transition section (201) away from the proximal tube body (104); a connecting line (203) is provided below the handle (202); and the connector (204) is connected to one end of the connecting line (203) away from the handle (202); The braided layer comprises an electrode wire (401) and a braided wire (402) that are braided with each other, and two ends of the electrode wire (401) are respectively connected to the electrode (301) and the connector (204).

2. A pulsed electric field ablation microcatheter according to claim 1, characterized in that: The catheter part adopts a hollow design, with an outer diameter of less than 3F and an inner diameter greater than or equal to 0.36mm.

3. A pulsed electric field ablation microcatheter according to claim 2, characterized in that: The outer layers of the damage-resistant section (101), the terminal tube body (102), the tube body transition section (103) and the proximal tube body (104) are made of Pebax or TPU polymer materials, and the hardness thereof gradually decreases from the proximal tube body (104) to the damage-resistant section (101).

4. The pulsed electric field ablation microcatheter according to claim 3, characterized in that: The number of the electrodes (301) is greater than 2, and the material thereof is preferably a platinum-iridium alloy, the electrode length is 1 mm to 3 mm, and the electrode spacing is 1 mm to 5 mm.

5. The pulsed electric field ablation microcatheter according to claim 1, characterized in that: The electrode wire (401) is a copper wire with a coating, and the coating material is PI or PET.

6. The pulsed electric field ablation microcatheter according to claim 6, characterized in that: The braided wire (402) is made of PET fiber.

7. The pulsed electric field ablation microcatheter according to claim 5, characterized in that: The number of the electrode wires (401) is the same as the number of the electrodes (301).

8. The pulsed electric field ablation microcatheter according to claim 1, characterized in that: The braided layer is heat-fused between the inner layer and the outer layer.

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