RF electrode ablation catheter with cooling function for ventricular septal procedures

Abstract

To provide an RF electrode excision catheter for ventricular septum treatment having a cooling function.SOLUTION: An RF catheter for ventricular septum treatment according to a preferred embodiment of the present invention comprises: a septum insertion part formed with a tapered tip narrowed as going to a terminal of a distal part at the terminal, and one or more electrodes in an outer circumferential surface at the position adjacent to the tip; and a soft material body part having a guide wire lumen formed with an outlet on the side penetrating through the inside of the septum insertion part from an inlet formed in the center of the tip terminal, a coolant drawing lumen connected from a proximal part to the inside of the septum insertion part and having the terminal opened so that the coolant can be injected from the outside, and a coolant discharge lumen in communication with the coolant drawing lumen and formed with a discharging outlet on the side. The guide wire lumen and the coolant drawing lumen are not brought into communication with each other, and are partitioned.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to an RF electrode ablation catheter for ventricular septal treatment having a cooling function, and more particularly to an RF electrode ablation catheter for ventricular septal treatment for performing RF electrode ablation by applying RF energy to the ventricular septum for ventricular septal reduction therapy, such as treatment for hypertrophic cardiomyopathy, a disease in which the ventricular septum of the left ventricle of an animal or human heart thickens, treatment requiring reduction of the ventricular septum, or ventricular tachycardia.

[0002] The present invention also relates to an RF electrode ablation catheter for ventricular septal treatment having a cooling function for preventing carbonization of the body (ventricular septum) tissue surrounding the electrode. [Background technology]

[0003] Septal reduction therapy includes procedures for hypertrophic cardiomyopathy, procedures requiring reduction of the ventricular septum, or ventricular tachycardia.

[0004] Hypertrophic cardiomyopathy, a representative type of ventricular septal surgery, is a heart disease in which the left ventricular wall thickens without other conditions such as aortic valve stenosis or high blood pressure that induce left ventricular hypertrophy. It is found in 1 out of every 500 people in the general population, and various types of left ventricular hypertrophy are observed. The most common and representative features are asymmetrical septal hypertrophy and variable left ventricular outflow tract obstruction.

[0005] FIG. 1 illustrates a diagram showing the symptoms of hypertrophic cardiomyopathy and the surgical procedure commonly performed today.

[0006] Referring to Figure 1, the general method of hypertrophic cardiomyopathy surgery is to insert a knife into the left ventricle through the aortic valve and then cut away the enlarged ventricular septum of the left ventricle as shown in the figure. That is, a method is used in which the enlarged ventricular septum is cut away using a knife according to the sense of a specialist.

[0007] Meanwhile, another method using RF energy has been recently reported. Treatment of septal hypertrophy through RF ablation has been reported many times in the past, but in all of these cases, a catheter was placed inside the left ventricle and RF ablation was performed on the surface of the left ventricle.

[0008] Recently, a technique has been reported that uses a needle to treat septal hypertrophy by penetrating into the interior rather than the surface, and it has been reported that it has shown surprisingly good results. That is, when RF electrode ablation was performed by approaching the intra-septum, it was reported that the treatment had excellent results.

[0009] (Percutaneous Intramyocardial Septal Radiofrequency Ablation for Hypertrophic Obstructive Cardiomyopathy.Journal of the American College of Cardiology Volume 72, Issue 16, October 2018)

[0010] However, the method described in the above paper has the disadvantage that it is very dangerous during the procedure because it uses a hard needle to approach the intra-septum. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] (Patent Document 0001) Korean Patent Publication No. 10-1626958 (registered on May 27, 2016) (High-frequency catheter equipped with multiple electrodes) [Non-patent literature]

[0012] [Non-Patent Document 1] (Non-Patent Document 0001) Percutaneous Intramyocardial Septal Radiofrequency Ablation for Hypertrophic Obstructive Cardiomyopathy. Journal of the American College of Cardiology Volume 72 (16, October 2018) Summary of the Invention [Problem to be solved by the invention]

[0013] The object of the present invention is to provide an RF electrode ablation catheter for ventricular septal treatment, which allows for easier transmission of radio frequency waves and a wider operating range by injecting a cooling saline solution (coolant) at the proximal part of the catheter to lower the temperature of the distal electrode and prevent carbonization around the electrode.

[0014] Another object of the present invention is to provide an RF electrode ablation catheter for ventricular septal treatment, which can reduce the outer diameter of the RF catheter, allowing it to smoothly and easily pass through narrow blood vessels in the heart, can reduce insulation problems that may occur in the catheter by minimizing the possibility of contact between the high frequency power supply line and the temperature sensor line, etc., and can inject the coolant with a lower pressure pump by shortening the length of the tube through which the coolant is delivered.

[0015] The object of the present invention is not limited to the object mentioned above, and other objects not mentioned will be clearly understood by those having ordinary skill in the art of the present invention from the following description. [Means for solving the problem]

[0016] The present invention has been made to achieve the above object, and an RF catheter for ventricular septal treatment according to a preferred embodiment of the present invention includes a tapered tip that becomes thinner toward the end of a distal portion so that it can be inserted through the ventricular septum, a septal insertion portion having one or more electrodes formed on the outer circumferential surface at a position adjacent to the tip; and a body portion made of a soft material having a guidewire lumen through which a guidewire can be inserted by penetrating the inside of the septal insertion portion at the center of the end of the tip, a coolant inlet lumen connected from a proximal portion to the inside of the septal insertion portion and having an open end so that a coolant can be injected from the outside, and a coolant outlet lumen connected to the coolant inlet lumen and having an outlet formed on a side surface;

[0017] The septum insertion portion is inserted through the myocardium along the guidance of the guide wire, and the guide wire lumen and the coolant inlet lumen are separated from each other and do not communicate with each other.

[0018] According to a preferred embodiment of the present invention, the coolant that flows from the proximal portion to the inside of the septal insertion portion through the coolant inlet lumen exits from the coolant outlet lumen and is then discharged into the coronary sinus or vein through an outlet formed on the side of the body portion.

[0019] According to a preferred embodiment of the present invention, the coolant discharge lumen has a structure surrounding the coolant inlet lumen, and coolant injected along the coolant inlet lumen flows in the opposite direction along the coolant discharge lumen surrounding the coolant inlet lumen and is discharged from the coronary sinus or vein through an outlet connected to the coolant discharge lumen.

[0020] According to a preferred embodiment of the present invention, the coolant discharge lumen has a structure surrounding the guidewire lumen, and the guidewire lumen passes through the coolant discharge lumen.

[0021] According to another preferred embodiment of the present invention, the guidewire lumen is located adjacent to the coolant discharge lumen without passing through the inside of the coolant discharge lumen.

[0022] According to a preferred embodiment of the present invention, the electrode is connected to an RF generator to receive RF energy and emit the RF energy, and also to sense electrical signals from the myocardium and apply electrical stimulation.

[0023] According to a preferred embodiment of the present invention, the guide wire lumen is in close contact with the guide wire passing therethrough, with no space therebetween.

[0024] According to a preferred embodiment of the present invention, the septal insert has a helical type coil wire or a braid type wire formed therein, and the wire is insulated from the electrode.

[0025] According to a preferred embodiment of the present invention, the septum insert has a hydrophilic polymer coating layer formed on the surface thereof except for the surface of the electrode.

[0026] According to a preferred embodiment of the present invention, the tapered tip has a length of 5-20 mm, a thickness of 1.2-1.4 Fr at the apex and a thickness of 3-6 Fr at the side opposite the apex.

[0027] According to a preferred embodiment of the present invention, the electrode wires for transmitting RF energy to the electrodes are coated and spirally wrapped around the surface of the catheter, and the electrode wires corresponding to the number of the electrodes are connected. Preferably, the electrode wires are silver wires.

[0028] According to a preferred embodiment of the present invention, two thermocouple wires are wound radially around the surface of the catheter from the proximal portion to the electrode while being wound around each other, in order to measure the temperature of the electrode, and more preferably, one of the thermocouple wires is a Nickel-Chromium wire which is harmless to the human body, and the other is a Nickel-Alumel wire which is harmless to the human body.

[0029] Effect of the Invention

[0030] The present invention has the following advantages.

[0031] 1. RF electrode ablation is performed using a soft RF electrode ablation catheter instead of a hard needle, so it can be smoothly inserted along the curved septal vein, making the procedure safer.

[0032] 2. The RF electrode ablation catheter can be passed through the coronary sinus and septal vein, eliminating complications that may occur when approaching the left ventricular endocarium through the coronary artery, aortic valve, or mitral valve, or by direct needle puncture.

[0033] 3. It is preferable to perform cooling during RF electrode ablation, which can reduce the risk of char (black spots) on the endocarium or tissue defects.

[0034] 4. When RF energy is delivered into the ventricular septum, (1) it has good contact with the surrounding tissue, (2) it can create homogenous lesions, which is an advantage of RF energy, and (3) it is possible to control the degree of tissue damage in stages by titrating the intensity of RF, so that sufficient therapeutic effects can be expected even with a small diameter structure (approximately 2 to 6 Fr) that can penetrate inside the ventricle.

[0035] 5. In addition, complete atrioventricular block can be prevented by avoiding tissue damage to the left ventricular endocardium, and arrhythmogeneity can be minimized by uniform tissue damage.

[0036] 6. RF Electrode The electrode formed on the surface of the ablation catheter not only serves to apply RF energy, but also to sense or stimulate the tissue.

[0037] Prior to performing RF electrode ablation, the safety of RF electrode ablation can be increased by directly sensing the electrical signals of the myocardium through the electrodes, or by applying electrical stimulation through the electrodes and then determining in advance whether the electrodes are located close to the His bundle of the myocardium through the electrocardiogram of the resulting pulsating rhythm. This has the advantage of increasing the reliability of the procedure of the present invention.

[0038] 7. The coolant outlet lumen has a structure that surrounds the coolant inlet lumen, which allows the outer diameter of the RF electrode ablation catheter to be reduced. In the case of RF electrode ablation catheters for ventricular septal procedures, which pass through narrow blood vessels in the heart and target the ventricular septum, it is extremely important to reduce the outer diameter of the catheter even further.

[0039] 8. The coolant discharge lumen has a structure surrounding the coolant inlet lumen, which reduces the outer diameter of the catheter and minimizes the possibility of contact between the high frequency power supply line and the temperature sensor line, thereby reducing insulation problems that may occur in the catheter. In addition, the length of the tube through which the saline solution (coolant) is delivered is shortened, which has the advantage that the saline solution can be injected with a lower pressure pump. [Brief description of the drawings]

[0040] [Figure 1] Illustrates the symptoms and surgical procedures for hypertrophic cardiomyopathy. [Diagram 2] 1 is a schematic diagram showing an RF electrode ablation catheter for ventricular septum treatment according to the present invention and a treatment method using the same. [Diagram 3] 1A and 1B are an overall perspective view, a partially enlarged view, and a partially sectional view of an RF electrode ablation catheter for ventricular septum treatment according to one embodiment of the present invention; [Figure 4] 1A and 1B are a cross-sectional view and a partially enlarged view of an RF electrode ablation catheter for ventricular septum treatment according to one embodiment of the present invention. [Diagram 5] 1 illustrates the shape of an electrode wire formed on the surface of an RF electrode ablation catheter for ventricular septum treatment and the catheter according to one embodiment of the present invention. [Figure 6] 13 illustrates the shape of an electrode wire formed on the surface of an RF electrode ablation catheter for ventricular septum treatment and the catheter according to another embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0041] The advantages and features of the present invention, and the method of achieving them, will become clear from the detailed description of the embodiments with accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be embodied in various different forms, and the embodiments are provided to complete the disclosure of the present invention and to fully inform those skilled in the art of the present invention of the scope of the invention, and the present invention is defined only by the scope of the claims.

[0042] The main gist of the present invention is to provide a soft catheter type RF electrode ablation catheter instead of a hard needle, and to provide a method for obtaining intra-myocardial or intraseptal ventricular septal treatment effects using the soft catheter, i.e., to provide a method for entering tissue using a soft catheter instead of a hard needle.

[0043] FIG. 2 is a schematic diagram showing the RF electrode ablation catheter for ventricular septum treatment according to the present invention and a treatment method using the same.

[0044] 2, the present invention positions a guidewire through the coronary sinus and septal vein to the enlarged ventricular septum, and then delivers an RF electrode ablation catheter to the treatment target site (i.e., the enlarged ventricular septum) along the pre-positioned guidewire. Then, while continuously injecting coolant from outside, RF energy is applied to an electrode formed at the end of the RF electrode ablation catheter using an RF generator to perform RF electrode ablation.

[0045] Preferably, prior to performing RF electrode ablation, the electrode can be used to sense electrical signals from the myocardium or to check the electrocardiogram of the pulsatile rhythm that occurs after electrical stimulation is applied to determine whether the electrode is in close proximity to the His bundle of the myocardium.

[0046] First, a method for positioning a guidewire (10) within a treatment target site (the enlarged ventricular septum) will be described.

[0047] A very thin guidewire (approximately 0.014" diameter) is used to pass through the coronary sinus and septal veins to the target location within the hypertrophied septum.

[0048] In the present invention, the coronary sinus, which has an opening in the right atrium, is used to access the ventricular septum, which is the treatment target of the ventricular septal procedure, through the septal vein. The coronary sinus is accessed through the neck vein or femoral vein, and a guiding catheter is used through the superior vena cava or inferior vena cava.

[0049] The guide catheter may be a balloon-terminated guide catheter and / or a dual lumen microcatheter, which is a catheter used to guide a guidewire to a desired location.

[0050] When approaching the coronary sinus, a guiding catheter is placed to the distal part of the coronary sinus and a pressurized venogram is performed through the guiding catheter. A balloon tipped guiding catheter is ideal for a pressurized venogram.

[0051] After imaging the septal veins through a pressurized venogram, a PTCA guidewire of approximately 0.014 inches is inserted into the septal vein closest to the target site. The PTCA guidewire uses real-time imaging equipment such as an echocardiogram to provide imaging guidance that indicates whether the wire is finding the target site, allowing for more precise treatment. To guide the direction of the PTCA guidewire more precisely, a dual lumen microcatheter can be used to precisely guide the wire to the target site.

[0052] That is, in order to position the guidewire in the interventricular septum through the septal vein, (1) a pressurized venogram with a balloon guiding catheter and / or (2) a dual lumen microcatheter, etc. may be used.

[0053] To better visualize the septal veins, a pressurized venogram is used, for which a balloon tipped guiding catheter may be used as an adjunct.

[0054] In addition, a dual lumen microcatheter can be used as an auxiliary means to position a guidewire in a desired direction within the ventricular septum. A dual lumen microcatheter is a catheter formed with two lumens for inserting a guidewire. After the first guidewire is positioned in the septal vein through the first lumen of the dual lumen microcatheter, the second guidewire is inserted through the second lumen of the dual lumen microcatheter. The second guidewire can be moved in a different direction from the first guidewire. Thus, the dual lumen microcatheter is a very useful auxiliary catheter for the procedure when searching for a desired guidewire target point within the ventricular septum.

[0055] In the septal vein, which is located within the ventricular septum tissue and not on the surface of the ventricular septum, the guidewire can be moved freely without problems such as bleeding. Since the septal vein is located within the ventricular septum, the guidewire is positioned (intra-septum) inside the enlarged myocardial septum using the septal vein. When using the septal vein, the guidewire can be moved to the desired location by passing through the septal vein as necessary. In this case, the dual lumen catheter mentioned above can be used.

[0056] Although a similar approach is theoretically possible using the coronary artery, it is often difficult to reach the target due to the variety of anatomical locations. In this case, if the guidewire passes through the septal artery, serious problems such as intramyocardial bleeding may occur. In addition, when operating on the coronary artery, thrombus and dissection often occur in the coronary artery, which can be fatal. Therefore, as in the present invention, the guidewire is inserted using the septal vein.

[0057] The approach through the septal vein of the present invention can eliminate complications associated with existing approaches such as approaching the left ventricular endocarium through the coronary artery, aortic valve, or mitral valve, or approaching by direct needle puncture.

[0058] Meanwhile, traditionally, alcohol has been injected into the septal artery as a treatment, but this also makes it difficult to control the distribution of alcohol, and the alcohol can be delivered to unwanted areas, causing problems such as unnecessary myocardial infarction, and often leads to conduction system disorders.

[0059] Next, an RF ablation catheter is positioned to the target site (inside the enlarged ventricular septum) along the guidewire placed in the enlarged ventricular septum. That is, after one or more guidewires are placed in the target site, an RF ablation catheter is inserted along the guidewire and positioned so that the electrode reaches the target site.

[0060] With the electrode of the RF electrode ablation catheter positioned at the target site (in the enlarged ventricular septum), coolant (saline) is injected from the outside through the coolant discharge lumen in the RF electrode ablation catheter, and RF energy is applied to the RF electrode formed at the end of the RF electrode ablation catheter using an RF generator, thereby performing RF electrode ablation.

[0061] Preferably, before performing RF electrode ablation, a step is performed to determine whether the electrode is located near the His of the myocardium. Whether the electrode is located near the His of the myocardium can be determined by directly sensing the electrical signal of the myocardium or by checking the electrocardiogram of the pulsating rhythm generated during electrical stimulation.

[0062] Referring to FIG. 2, the RF electrode ablation catheter of the present invention is inserted through the superior vena cava (SVC) or inferior vena cava (IVC), passing through the right atrium (RA), the coronary sinus (CS), and then penetrating the ventricular septum. In this state, RF energy is supplied to the electrode to perform ablation. In the RF electrode ablation catheter of the present invention, coolant injected from the proximal part comes out of the coolant discharge lumen and is discharged to the outlet of the coolant discharge lumen formed on the side of the body part. Since the outlet is located in the coronary sinus, right atrium, or superior vena cava (or inferior vena cava), the coolant flows into the coronary sinus, right atrium, or vein.

[0063] 2, the location of the outlet of the coolant outlet lumen through which the coolant is discharged is located at CS1, CS2, CS3, RA, or SVC indicated by a red arrow. Here, CS1, CS2, CS3, RA, and SVC only roughly indicate the location where the outlet can be located, and do not necessarily mean the exact location limited thereto. In other words, the location of the outlet through which the coolant is discharged may be located at any point between CS, RA, and SVC (or IVC).

[0064] FIG. 3 is an overall perspective view, a partially enlarged view, and a partially sectional view of an RF electrode ablation catheter for ventricular septum treatment according to one embodiment of the present invention, and FIG. 4 is a partially enlarged view and a sectional view of the RF electrode ablation catheter.

[0065] 3 and 4, the RF electrode ablation catheter 100 is roughly divided into a body part (130) and an intra-septal part (120).

[0066] The intra-septal part (120) is a part formed in the distal part of the body part 130, and is the part to be inserted into the ventricular septum. It has a diameter of about 3 to 6 Fr (preferably about 4 Fr), and is a size that causes little damage to the ventricular septum when inserted into the ventricular septum.

[0067] The intra-septal part (110) includes an electrode (124) having one or more electrodes formed on its surface, and a tapered tip (tissue penetrating tip (122) that becomes thinner toward its end so that it can penetrate the ventricular septum along a guidewire.

[0068] Preferably, the length of the tapered tip 122 is approximately 5 to 20 mm (preferably about 10 mm), and the apex has a thickness of approximately 1.2 to 1.4 Fr. The side opposite the apex has the same thickness as the outer shape of the septal insertion part (preferably 3 to 6 Fr, more preferably 4 to 5 Fr). The tapered tip 122 is 5 to 20 times longer than the thickness of the side opposite the apex (i.e., the outer thickness of the septal insertion part), giving it a very long and thin tip shape.

[0069] The RF ablation catheter (100) has a guidewire lumen through which a guidewire is inserted so that the RF ablation catheter can be inserted into the ventricular septum along the guidewire located in the ventricular septum. An entrance 112 of the guidewire lumen 110 is formed at the end of the septal insertion portion.

[0070] Preferably, there should be no space between the guidewire and the entrance 112 of the guidewire lumen, i.e., there should be a high precision structure without mismatch between the guidewire and the end of the tip.

[0071] The reason why there should be no space between the entrance of the guidewire lumen and the guidewire is that when the tip enters the inside of the ventricular septum, it is necessary to minimize resistance and not damage the tissue of the ventricular septum. This is because the tapered tip 122 of the present invention must penetrate the ventricular septum tissue while functioning like a needle. If a space is formed between the entrance of the guidewire lumen and the guidewire, the tapered tip will encounter resistance from the ventricular septum tissue when it is inserted into the ventricular septum, which may result in damage to the ventricular septum tissue.

[0072] Since the RF electrode ablation catheter must be inserted into the ventricular septum along the guidewire, it goes without saying that the RF electrode ablation catheter must be able to move along the guidewire through the guidewire lumen, although the entrance of the guidewire lumen and the guidewire are in close contact with each other.

[0073] The intra-septal part is provided with one or more electrodes, which not only sense electrical signals from the myocardium and provide electrical stimulation, but also transmit RF energy from the RF generator.

[0074] The electrodes are connected to electrode wires (shown in FIGS. 5 and 6), which are connected to the inside or outside of the catheter to a proximal portion and then exit the catheter to be connected to an external connector. Depending on which external connector is connected, the electrodes can perform various functions such as not only emitting RF high frequency waves but also sensing electrical signals and providing electrical stimulation.

[0075] In order to determine whether an electrode is located near the His bundle of the myocardium (i.e., to grasp the location of the conduction system), the electrode is used to directly sense the electrical signal of the myocardium or to apply electrical stimulation (pacing). Also, in order to perform RF electrode ablation, the electrode is used to deliver RF energy from an RF generator. That is, the electrode can be used in various ways, such as to determine whether an electrode is located near the His bundle of the myocardium and to deliver RF energy.

[0076] First, when the electrode is used to determine whether it is located near the myocardial His, it is used to directly sense the electrical signal of the myocardium or to apply electrical stimulation to the myocardium. When applying electrical stimulation to the myocardium, the location of the conduction system such as the His can be indirectly determined by checking the electrocardiogram of the pulsating rhythm generated by the electrical stimulation.

[0077] Although the RF ablation catheter can easily approach the ventricular septum, there is a risk of it being located close to the His bundle in the myocardium. If RF ablation is performed with the electrode of the RF ablation catheter close to the His bundle in the myocardium, there is a risk of RF ablation of the cardiac conduction system, which may destroy the cardiac conduction system.

[0078] To prevent this, in the present invention, the location of the conduction system such as His must be identified through the electrodes before performing RF electrode ablation. For this purpose, the electrodes perform the role of sensing or electrical stimulation (pacing). The location of the conduction system can be identified by directly sensing the electrical signal of the myocardium using the electrodes, or the location of the conduction system such as His can be indirectly identified through the electrocardiogram of the pulsating rhythm generated by applying electrical stimulation to the myocardium using the electrodes.

[0079] If the electrode is located near the His, the RF electrode ablation catheter must be repositioned to another location.

[0080] Only when the electrode is sufficiently removed from the His bundle, an external connector connected to the electrode is connected to an RF generator to apply RF energy and perform RF electrode ablation.

[0081] When performing RF ablation, the connector connected to the electrode is connected to an RF generator, and RF energy from the RF generator is transmitted to the electrode to perform RF ablation.

[0082] When one or more electrodes are formed, some of the electrodes can be used for RF electrode ablation and the remaining electrodes can be used for sensing or electrical stimulation (pacing). That is, the electrodes can be divided according to their purpose into electrodes used for RF electrode ablation and electrodes used for sensing or electrical stimulation.

[0083] In other cases, the electrode may not be divided into two uses, but may be used for both sensing or electrical stimulation and RF electrode ablation, i.e., the electrode may be used for sensing or electrical stimulation first, and then the connector connected to the electrode may be connected to an RF generator to use the electrode as an electrode for applying RF energy.

[0084] In the present invention, the proximal part of a catheter refers to one end of the catheter, which is the end where the catheter exits the human body, and the distal part of a catheter refers to the other end of the catheter, which is the end that is inserted into the human body.

[0085] Although not shown, the septal insert 120 is preferably formed with an insulated spiral coil wire or braided wire inside. This is to prevent the septal insert from bending when inserted into the ventricular septum and to improve pushability and trackability. Pushability is the ability to transmit force from the proximal end to the distal end while reducing bending, and trackability is the ability to inject the catheter along complex blood vessels (Pushability is often understood as the ability to transmit force from the proximal end of the catheter to the distal end of the catheter while minimizing or eliminating kinking. Trackability is often understood as the ability to navigate the catheter through tortuous vasculature). It goes without saying that both the spiral coil wire and the braided wire must be insulated from the electrode or electrode wire.

[0086] Preferably, the septal insert may have a hydrophilic polymer coating formed on its surface. This is to allow the septal insert to move more easily into the ventricular septal tissue. Since the hydrophilic polymer coating is harder than a soft catheter, the septal insert may be inserted more easily into the ventricular septal tissue. Since the electrodes must be exposed on the surface, the hydrophilic polymer coating is not formed on the area where the electrodes are formed.

[0087] The body part (130) is the part that forms the body of the catheter. The outer diameter of the body part (130) is the same as or larger than the outer diameter of the intraseptal part (120). The body part (120) must have sufficient stiffness to efficiently push the intraseptal part into the ventricular septum without causing kinking.

[0088] Preferably, the body part, like the septum insertion part, can have an insulated spiral coil wire or braided wire inside, which can prevent the catheter from bending and improve pushability and trackability.

[0089] Meanwhile, if the temperature rises too high when applying RF energy using an RF electrode ablation catheter, not only can chars (black spots) form on the ventricular septum, but tissue defects can also occur in the myocardium. Also, when the tissue is suddenly burned, gas is released, causing a sudden increase in pressure within the tissue, resulting in a barotrauma, which can lead to a risk of heart perforation.

[0090] During RF electrode ablation, the RF electrode ablation site must be cooled using coolant (saline solution). To cool the area, coolant must be injected into the RF electrode ablation catheter.

[0091] The coolant injected from the proximal part cools the temperature of the electrode in the septal insertion part, and then returns to the proximal part or can be discharged from the side of the body part.

[0092] Fig. 3 is an overall perspective view, a partially enlarged view, and a partially sectional view of an RF electrode ablation catheter for ventricular septum treatment according to one embodiment of the present invention. Fig. 4 is a partially enlarged view and a partially sectional view of an RF electrode ablation catheter for ventricular septum treatment according to one embodiment of the present invention.

[0093] 3 and 4, in the RF electrode ablation catheter illustrated in FIGS. 3 and 4, coolant (saline) is injected from the proximal portion through the coolant inlet lumen 140 and enters the inside of the septal insertion portion 120 where the electrode 124 is located, then comes out of the coolant outlet lumen 150, flows again in the opposite direction along the coolant outlet lumen, and is discharged through the outlet 152 of the coolant outlet lumen 150 formed on the side of the body portion 130.

[0094] When performing ventricular septal surgery using the RF electrode ablation catheter of the present invention, the RF catheter is inserted along a guide wire, and the tip 122 at the end of the distal portion penetrates the ventricular septum (myocardium) and is inserted into the ventricular septum. At this time, the outlet 152 of the coolant discharge lumen 150 formed on the side of the body 130 is located in the coronary sinus, right atrium, or vein, so that the discharged coolant is discharged from the coronary sinus, right atrium, or vein.

[0095] The guidewire lumen 110 is a lumen for inserting a guidewire and is an essential element for inserting an RF catheter into a target (the ventricular septum) along the guidewire. The guidewire lumen 110 passes through the inside of the septal insertion part 120 from an entrance 112 formed at the center of the tip end, and an exit 114 is formed on the side of the body part.

[0096] The exit 114 of the guidewire lumen 110 may be formed in various positions, and may be formed in the proximal or middle part of the body, or in the distal part. Preferably, as shown in Figures 3 and 4, the exit 114 of the guidewire lumen is formed in the proximal part of the body. This is to make it possible for the guidewire and the catheter to be separated from each other as little as possible and for the RF catheter to be easily inserted along the guidewire by positioning the guidewire inside the RF catheter.

[0097] The guidewire lumen 110 is not in communication with the coolant discharge lumen 150 and is therefore partitioned from the other lumen, i.e., separated and separated from the other lumen, so that the guidewire moving along the guidewire lumen is not obstructed by the coolant flowing through the coolant discharge lumen.

[0098] Preferably, the coolant discharge lumen has a structure surrounding the guidewire lumen, that is, the guidewire lumen is located inside the coolant discharge lumen.

[0099] The coolant inlet lumen 150 is a passage for introducing coolant into the inside of the RF catheter, and is connected from the proximal part to the inside of the septal insertion part so that coolant can be injected from the outside, and its end is open. Therefore, the coolant flowing in from the outside is injected into the inside of the septal insertion part.

[0100] The coolant inlet lumen and the coolant outlet lumen are connected to each other, and more preferably, the coolant outlet lumen surrounds the coolant inlet lumen near the septum insertion portion (distal portion), i.e., the coolant inlet lumen is located inside the coolant outlet lumen.

[0101] The coolant injected from the proximal part through the coolant inlet lumen 140 flows into the coolant inlet lumen, and then, because the end of the coolant inlet lumen is open, it exits the coolant inlet lumen and flows along the inside of the coolant outlet lumen that surrounds the coolant inlet lumen.

[0102] The RF electrode is located on the outer surface of the septal insertion part, and the end of the coolant inlet lumen is connected to the inside of the septal insertion part, so that the coolant can be injected into the septal insertion part to cool the electrode and the catheter. Meanwhile, the end of the coolant outlet lumen is closed, so that the coolant flows in the opposite direction along the coolant outlet lumen and is then discharged to the outside through the outlet 152 formed on the side of the body.

[0103] Conventional catheters that are cooled with coolant (saline solution) have a structure in which a coolant inlet lumen and a coolant outlet lumen are connected inside the catheter from the proximal to the distal end.

[0104] However, in the present invention, the coolant discharge lumen is not connected to the proximal part of the catheter, but an outlet is formed on the side of the body part, and the coolant is discharged into the coronary sinus, right atrium, or superior vena cava (or inferior vena cava), and the coolant discharge lumen is structured to surround the coolant inlet lumen.

[0105] Accordingly, the catheter of the present invention has an advantage that the outer diameter of the catheter can be reduced since it is not necessary to form a separate coolant discharge tube up to the proximal portion. In particular, in the case of an RF electrode ablation catheter for ventricular septum treatment, which targets the ventricular septum through narrow blood vessels in the heart, it is very important to further reduce the outer diameter of the catheter.

[0106] In addition, by minimizing the possibility of contact between the high frequency power supply line and the temperature sensor line, etc., it is possible to reduce insulation problems that may occur in the catheter, and by shortening the length of the tube through which the saline solution (coolant) is delivered, it has the advantage that the saline solution can be injected with a lower pressure pump.

[0107] Meanwhile, depending on the method of applying a potential during RF electrode ablation, there are two main methods: a monopolar mode RF ablation catheter and a bipolar mode RF ablation catheter.

[0108] A monopolar mode RF ablation catheter is a catheter in which only one identical polarity is applied to all electrodes of the RF ablation catheter, and a bipolar mode RF ablation catheter is a catheter in which different polarities are applied to the electrodes of the catheter.

[0109] When a dual polarity mode RF electrode ablation catheter is used, a separate grounding device is not required, but when a single polarity mode RF electrode ablation catheter is used, a separate grounding device is required.

[0110] When using a unipolar mode RF electrode ablation catheter, the ground device may be located at different locations on the body or within the ventricular septum.

[0111] When the grounding device is positioned at a different part of the human body, the RF electrode ablation catheter is positioned in the ventricular septum, and a ground plate (grounding device) is grounded to a different part of the human body (such as the back, buttocks, calf, etc.), and then RF energy is applied to the electrode of the RF electrode ablation catheter to perform RF electrode ablation.

[0112] When the grounding device is positioned in the ventricular septum, the RF electrode ablation catheter is positioned in the ventricular septum, and a grounding device that acts as a ground is positioned around the electrode of the RF electrode ablation catheter, and then RF energy is applied to the electrode of the RF electrode ablation catheter to perform RF electrode ablation.

[0113] 3 and 4 show the state where multiple electrodes are formed, but only one electrode may be formed for RF ablation, in which case it would be considered a single polarity mode. If one electrode is formed in the septal insertion portion, an electrode with a width as large as the 3-4 electrodes shown in FIG. 3 would be formed.

[0114] Meanwhile, as shown in FIG. 3 and FIG. 4, the guide wire lumen may be formed inside the coolant discharge lumen, but is not necessarily limited thereto.

[0115] The coolant discharge lumen may be adjacent to the coolant discharge lumen without passing through the inside of the coolant discharge lumen. That is, the guidewire lumen may be formed separately from the coolant discharge lumen without passing through the inside of the coolant discharge lumen. In this case, the diameter of the coolant discharge lumen may be smaller, but the guidewire lumen may have a more stable structure since there is no left-right movement of the coolant discharge lumen within the coolant discharge lumen.

[0116] FIG. 5 illustrates the shape of electrode wires formed on the surface of an RF electrode ablation catheter for ventricular septal treatment and the catheter according to one embodiment of the present invention.

[0117] The RF ablation catheter for ventricular septum treatment shown in FIG. 5 has a structure having four electrodes. Preferably, the width of the electrodes is about 1 mm to 10 mm. Each of the four electrodes is connected to a respective electrode wire, and a thermocouple wire for measuring the temperature at the distal part of the catheter is connected. The electrode wire and the thermocouple wire are connected at the proximal part of the catheter. Each of the four electrodes has a width of about 1 mm, but this is not necessarily limited thereto, and it goes without saying that the width can be appropriately adjusted depending on the number of electrodes. When the number of electrodes is small, electrodes with a larger width are used, and when the number of electrodes is large, the width of the electrodes can be small. Also, electrodes with different widths can be used in one catheter.

[0118] The RF energy supplied to the electrode is formed through a silver wire wound in a spiral shape on the surface of the catheter. That is, the RF energy for performing RF ablation is supplied to the electrode (124) through an electrode wire wound in a spiral shape on the surface of a catheter made of a soft plastic material.

[0119] The electrode wire is a wire that supplies RF energy, and preferably a silver wire is used. The silver wire is insulated (coated) with a plastic material that is harmless to the human body. The RF ablation catheter of the present invention is inserted into the human body (coronary sinus, right atrium, vein). Since the electrode wire surrounds the surface of the catheter, if the coating of the electrode wire peels off when the catheter is inserted into the coronary sinus, right atrium, or vein, it will come into contact with tissue, so materials such as copper that are harmful to the human body cannot be used. Therefore, in the present invention, a silver wire that is harmless to the human body is used as the electrode wire.

[0120] In the present invention, by using a silver wire as an electrode wire for transmitting RF energy, it is possible to obtain the advantage of improving the straightness of the catheter by forming it in a spiral shape on the surface of the catheter, thereby improving the pushability.

[0121] On the other hand, as shown in Figure 5, in addition to the silver wire of the electrode wire, a thermocouple wire is spirally wrapped around the surface of the catheter at a distance from the electrode wire. The thermocouple wire is also covered with a harmless plastic material.

[0122] Thermocouple wire is used to measure the temperature around the electrode. In other words, thermocouple wire is a wire used as a thermocouple thermometer. Thermocouple wire is a type of two coated wires wound around each other, and is wound radially on the surface of the catheter, spaced apart from the electrode wire (silver wire). Thermocouple wire is coated all over, but the coating is removed at the ends to connect them and use them as a thermocouple thermometer.

[0123] Currently, various types of thermocouple wires are used, but in the present invention, since the thermocouple wire is wound around the surface of the catheter to be inserted into the human body, nickel-chromium / nickel-alumel, which is harmless to the human body even if the coating is peeled off, is used. That is, one of the thermocouple wires is a nickel-chromium wire, which is harmless to the human body, and the other is a nickel-alumel wire, which is harmless to the human body.

[0124] The thermocouple wire of the present invention is also wound in a spiral shape on the surface of the catheter, which has the advantage of improving the straightness of the catheter and improving its pushability.

[0125] As described above, the number of electrodes can be changed, and it goes without saying that the number of electrode lines supplying power to the electrodes will also be changed depending on the number of electrodes.

[0126] 6 shows the shape of the electrode wire formed on the surface of an RF electrode ablation catheter for ventricular septum treatment according to another embodiment of the present invention, and the catheter, in which one electrode is used.

[0127] Referring to Fig. 6, the electrode is formed in a form in which one wide electrode (124) is wound in a coil. Since there is only one electrode, one electrode wire is also formed to supply RF energy to the electrode. The electrode wire is coated and is formed by being wound in a spiral shape on the surface of the catheter. As for the material, a silver wire that is safe for the human body even if the coating is peeled off can be used.

[0128] In addition to the electrode wire, a thermocouple wire for measuring the temperature at the distal part of the catheter is wound in a spiral shape on the surface of the catheter. The thermocouple wire is also coated, and the two wires are twisted together and wound in a spiral shape on the surface of the catheter. The structure and material of the thermocouple wire are as described above.

[0129] As described above in detail, RF electrode ablation is performed by inserting coolant into the RF electrode ablation catheter while the electrode of the RF electrode ablation catheter is positioned in the ventricular septum. After the RF electrode ablation is performed and the intended therapeutic effect is sufficiently obtained, all the devices are removed to complete the RF electrode ablation for ventricular septal treatment.

[0130] Although the embodiments of the present invention have been described above with reference to the attached drawings, those skilled in the art will understand that the present invention can be embodied in other specific forms without changing the technical spirit or essential features of the present invention. Therefore, it should be understood that the embodiments described above are illustrative in all respects and are not limiting. [Explanation of symbols]

[0131] 10: Guide wire 100: RF ablation catheter 110: Guidewire lumen 112:Entrance 114:Exit 120: Intra-septal part 122: Tapered tip 124:electrode 130:body part 140: Coolant inlet lumen 150: Coolant outlet lumen 152:Exit 160: Handle 162: Coolant inlet 164: Power cable

Claims

1. In the RF catheter for ventricular septal surgery, A septal insertion part having a tapered tip at the end of the distal part, the tip becoming thinner toward the end of the tip, so that the tip can be inserted through the ventricular septum, and one or more electrodes formed on the outer circumferential surface at a position adjacent to the tip; and a guide wire lumen through which a guide wire can be inserted by penetrating the inside of the septum insertion part at the center of the tip end, a coolant inlet lumen connected from a proximal part to the inside of the septum insertion part and having an open end so that coolant can be injected from the outside, and a body part made of a soft material having a coolant outlet lumen connected to the coolant inlet lumen and having an outlet formed on a side surface; The septal insertion section is inserted through the myocardium along the guidance of the guide wire, The guide wire lumen and the coolant inlet lumen are separated from each other and do not communicate with each other, The RF catheter for ventricular septal treatment, wherein the guide wire lumen has a guide wire exit for inserting the guide wire on the side surface of the body portion.

2. 2. The RF catheter for ventricular septal treatment according to claim 1, wherein the coolant that has flowed from the proximal portion to the inside of the septal insertion portion through the coolant inlet lumen exits the coolant outlet lumen and is then discharged from the coronary sinus, the right atrium, or a vein through an outlet port formed on a side of the body portion.

3. The coolant discharge lumen has a structure surrounding the coolant inlet lumen, 2. The RF catheter for ventricular septum treatment according to claim 1, wherein the coolant injected along the coolant inlet lumen flows in the opposite direction along the coolant outlet lumen surrounding the coolant inlet lumen and is discharged from the coronary sinus, the right atrium, or a vein through an outlet port connected to the coolant outlet lumen.

4. The coolant discharge lumen has a structure surrounding the guide wire lumen, The RF catheter for ventricular septal treatment according to claim 1, wherein the guide wire lumen passes through the coolant discharge lumen.

5. 2. The RF catheter for ventricular septal treatment according to claim 1, wherein the guide wire lumen is positioned adjacent to the coolant discharge lumen without passing through the inside of the coolant discharge lumen.

6. 2. The RF catheter for ventricular septum treatment according to claim 1, wherein the electrode is connected to an RF generator to receive RF energy and emit the RF energy, and also to sense electrical signals from the myocardium and to apply electrical stimulation.

7. 2. The RF catheter for ventricular septum treatment according to claim 1, wherein the guide wire lumen is in close contact with the guide wire passing therethrough, with no space therebetween.

8. 2. The RF catheter for ventricular septal treatment according to claim 1, wherein the septal insertion portion has a spiral type coil wire or a braid type wire formed therein, and the wire is insulated from the electrode.

9. 2. The RF catheter for ventricular septal treatment according to claim 1, wherein the septal insertion part has a hydrophilic polymer coating layer formed on a surface thereof except for a surface of the electrode.

10. 2. The RF catheter for ventricular septum treatment according to claim 1, wherein one end of the guidewire lumen is formed at the center of the tip end and the other end is formed at a side of the catheter or at a proximal end of the catheter.

11. The RF catheter for ventricular septum treatment according to claim 1, wherein the tapered tip has a length of 5 to 20 mm, a thickness of the apex of 1.2 to 1.4 Fr, and a thickness of the opposite side of the apex of 3 to 6 Fr.

12. 2. The RF catheter for ventricular septum treatment according to claim 1, wherein the electrode wires for transmitting RF energy to the electrodes are coated and spirally wrapped around the surface of the catheter, and the electrode wires corresponding to the number of the electrodes are connected.

13. The RF catheter for ventricular septal treatment according to claim 12, wherein the electrode wire is a silver wire.

14. 2. The RF catheter for ventricular septal treatment according to claim 1, wherein two thermocouple wires are wound around each other radially on the surface of the catheter from the proximal portion to the distal portion in order to measure the temperature of the electrode.

15. 15. The RF catheter for ventricular septal treatment according to claim 14, wherein one of the thermocouple wires is a nickel-chromium wire which is harmless to the human body, and the other is a nickel-alumel wire which is harmless to the human body.

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