Long electrode concept for discrete cutting with radiofrequency energy in electrosurgical applications

Abstract

An electrosurgical device for discrete cutting of target tissue adjacent to non-target tissue, the electrosurgical device comprising an elongate shaft having a proximal portion including a proximal end and a distal portion including a distal end. At least one electrode is configured to cut the target tissue. The at least one electrode has a surface area and is located on the distal portion. The distal portion is electrically insulated from the at least one electrode and has a surface area that is substantially larger than the surface area of the at least one electrode. The distal portion is configured to prevent the distal portion from moving into an incision or puncture formed in the target tissue by applying energy to the at least one electrode.

Description

[0001] Cross-references to related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 616,342, filed December 29, 2023, entitled “LONG-ELECTRODE CONCEPT FORDISCRETE CUTTING WITH RF ENERGY IN ELECTROSURGICAL APPLICATIONS,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] This disclosure relates to medical systems and methods for discretizing tissues within a patient's body. More specifically, this disclosure relates to medical systems and methods for discretizing target tissue adjacent to non-target tissue. Background Technology

[0004] The use of radio frequency (RF) energy to cut or vaporize biological tissue is a widely used technique in surgical applications. Target tissue can be vaporized using a conductive material that delivers RF energy at a specific voltage, frequency, and current density to the target tissue. This can be used to ligate or cut tissue with a cauterization pen in general electrosurgery, or to access locations in the body or vascular system via non-invasive percutaneous surgery. For example, RF energy is often applied to puncture the interatrial septum (IAS) during percutaneous transatrial approach from the right atrium to the left atrium in the heart. In these cases, controlling the depth of tissue penetration is not necessary because the IAS is flanked by open spaces in the left and right atria.

[0005] In some applications, it is necessary to deliver RF energy to precise tissue at a precise depth. For example, in cases where the pericardial sac surrounding the outer surface of the heart is approached percutaneously, it must be punctured without entering the myocardium. Here, the target tissue is adjacent to non-target tissue that does not require vaporization. In these situations, electrosurgical tools that precisely deliver RF energy only to the target tissue would greatly benefit both the user and the patient by reducing the risk of cutting, puncturing, vaporizing, or otherwise damaging the non-target tissue.

[0006] To perform cutting in electrosurgery, electrodes are typically designed to have a diameter of approximately 1-3 mm. 2The small surface area of ​​the cautery probe, surrounded by a non-conductive material, allows it to provide sufficient current density at the desired voltage and frequency. In routine surgery, the electrodes of the cautery probe are designed to advance indiscriminately through or ligate the target tissue because clinicians have a direct view of both target and non-target tissues and can precisely control the force and location applied to the tissue. For percutaneous intravascular coagulation (IAS), clinicians have far less direct control over the force and location of the RF probe, but discrete cutting is less critical because there is typically no non-target tissue adjacent to the IAS.

[0007] Developing radiofrequency probes that facilitate discrete tissue cutting in situations where clinicians have limited control over electrode force and placement or cannot visually confirm characteristics such as thickness and flexibility may be advantageous. Electrodes designed to not advance directly through the target tissue could reduce complications from indiscriminate cutting of non-target tissues in these applications. Summary of the Invention

[0008] Example 1 is an electrosurgical device for discretely cutting target tissue adjacent to non-target tissue. The electrosurgical device includes an elongated shaft having a proximal portion including a proximal end and a distal portion including a distal end. At least one electrode is configured to cut the target tissue. The at least one electrode has a surface area and is located on the distal portion. The distal portion is electrically insulated from the at least one electrode and has a surface area significantly larger than that of the at least one electrode. The distal portion is configured to prevent movement into an incision or puncture site formed in the target tissue by applying energy to the at least one electrode.

[0009] Example 2 is an electrosurgical device according to Example 1, wherein the elongated shaft includes a lumen extending from the proximal end to the distal end.

[0010] Example 3 is an electrosurgical device according to any one of Examples 1 or 2, wherein the at least one electrode is formed of a wire having one or more rectangular, circular, elliptical, square or polygonal cross-sections.

[0011] Example 4 is an electrosurgical device according to any one of Examples 1-3, wherein the at least one electrode is formed of a conductive metal.

[0012] Example 5 is an electrosurgical device according to any one of Examples 1-4, further comprising at least one wire configured to electrically connect the at least one electrode to a control system.

[0013] Example 6 is an electrosurgical device according to Example 5, wherein the at least one wire extends proximally from the at least one electrode through a wire lumen to the proximal end of the elongated shaft.

[0014] Example 7 is an electrosurgical device according to Example 5, wherein the at least one wire forms the at least one electrode.

[0015] Example 8 is an electrosurgical device according to any one of Examples 1-7, further comprising a connector located at the proximal end, the connector being configured to electrically connect the electrosurgical device to a control system.

[0016] Example 9 is an electrosurgical device according to any one of Examples 1-8, wherein the at least one electrode extends longitudinally along the outer surface of the distal portion.

[0017] Example 10 is an electrosurgical device according to Example 9, wherein the outer surface tapers towards the distal end.

[0018] Example 11 is an electrosurgical device according to any one of Examples 1-10, wherein the at least one electrode is located in a recess or groove along the distal portion.

[0019] Example 12 is an electrosurgical device according to any one of Examples 1-11, wherein the at least one electrode extends along the longitudinal axis of the elongated shaft.

[0020] Example 13 is an electrosurgical device according to any one of Examples 1-12, wherein the at least one electrode has a diameter greater than 1.0 mm. 2 Smaller surface area.

[0021] Example 14 is an electrosurgical device according to any one of Examples 1-13, wherein the at least one electrode is located on the distal side of the elongated shaft.

[0022] Example 15 is an electrosurgical device according to any one of Examples 1-14, wherein the at least one electrode comprises a plurality of electrodes.

[0023] Example 16 is an electrosurgical device for discretely cutting the pericardium adjacent to myocardium. The electrosurgical device includes an elongated shaft having a proximal portion including a proximal end and a distal portion including a distal end. At least one electrode is configured to cut the pericardium. The at least one electrode includes a surface area and is located on the distal portion. The distal portion is electrically insulated from the at least one electrode and has a surface area significantly larger than that of the at least one electrode. The distal portion is configured to prevent movement into an incision or puncture site formed in the pericardium by applying energy to the at least one electrode.

[0024] Example 17 is an electrosurgical device according to Example 16, wherein the elongated shaft includes a lumen extending from a proximal end to a distal end.

[0025] Example 18 is an electrosurgical device according to Example 16, wherein the at least one electrode is formed of a wire having one or more rectangular, circular, elliptical, square or polygonal cross-sections.

[0026] Example 19 is an electrosurgical device according to Example 16, wherein the at least one electrode is formed of a conductive metal.

[0027] Example 20 is an electrosurgical device according to Example 16, further comprising at least one wire configured to electrically connect the at least one electrode to a control system.

[0028] Example 21 is an electrosurgical device according to Example 20, wherein the at least one wire extends proximally from the at least one electrode through a wire lumen to the proximal end of the elongated shaft.

[0029] Example 22 is an electrosurgical device according to Example 20, wherein the at least one wire forms the at least one electrode.

[0030] Example 23 is an electrosurgical device according to Example 16, further comprising a connector located at the proximal end, the connector being configured to electrically connect the electrosurgical device to a control system.

[0031] Example 24 is an electrosurgical device according to Example 16, wherein the at least one electrode extends longitudinally along the outer surface of the distal portion.

[0032] Example 25 is an electrosurgical device according to Example 24, wherein the outer surface tapers towards the distal end.

[0033] Example 26 is an electrosurgical device according to Example 16, wherein the at least one electrode is located in a recess or groove along the distal portion.

[0034] Example 27 is an electrosurgical device according to Example 16, wherein the at least one electrode has a diameter greater than 1.0 mm. 2 Smaller surface area.

[0035] Example 28 is an electrosurgical device according to Example 16, wherein the at least one electrode is located on the distal side of the elongated shaft.

[0036] Example 29 is an electrosurgical device according to Example 16, wherein the at least one electrode comprises a plurality of electrodes.

[0037] Example 30 is an electrosurgical device for discretely cutting the pericardium adjacent to myocardium. The electrosurgical device includes an elongated shaft having a proximal portion including a proximal end and a tapered distal portion including a distal end. At least one electrode is configured to cut the pericardium. The at least one electrode includes a surface area and extends longitudinally along the outer surface of the distal portion. The distal portion is electrically insulated from the at least one electrode and has a surface area significantly larger than that of the at least one electrode. The distal portion is configured to prevent movement into an incision or puncture site formed in the pericardium by applying energy to the at least one electrode.

[0038] Example 31 is a method for discretely cutting target tissue using radiofrequency energy. The method includes providing an electrosurgical device. The electrosurgical device includes an elongated shaft having a proximal portion including a proximal end and a distal portion including a distal end. At least one electrode is configured to cut the target tissue. The at least one electrode has a surface area and extends longitudinally along the outer surface of the distal portion. The distal portion is electrically insulated from the at least one electrode and has a surface area significantly larger than that of the at least one electrode. The method includes advancing the electrosurgical device to a target location within a patient. The method includes providing radiofrequency energy to the at least one electrode and forming an incision in the target tissue. The distal portion contacts tissue adjacent to the incision to prevent the distal portion from moving into the incision.

[0039] Example 32 is the method according to Example 31, wherein the distal portion tapers toward the distal end.

[0040] Example 33 is the method according to Example 31, wherein the elongated shaft includes a lumen extending from the proximal end to the distal end.

[0041] Example 34 is the method according to Example 31, wherein the target tissue is the pericardium.

[0042] Example 35 is the method according to Example 34, further comprising advancing a guidewire through the incision and into the pericardial space.

[0043] While several embodiments have been disclosed, other embodiments of this disclosure will become apparent to those skilled in the art from the following detailed description, which illustrates and describes illustrative embodiments of this disclosure. Therefore, the accompanying drawings and detailed description should be considered illustrative in nature and not restrictive. Attached Figure Description

[0044] Figure 1 This is a perspective view of an electrosurgical apparatus for discretely cutting tissue according to an embodiment of the present disclosure.

[0045] Figure 2This is a perspective view of an electrosurgical apparatus for discretely cutting tissue according to an embodiment of the present disclosure.

[0046] Figures 3A-3E Various cross-sections of metal wires or conductors forming RF electrodes according to this disclosure are shown.

[0047] Figures 4A-4C Various cross-sectional views of an electrosurgical device according to this disclosure are shown, illustrating various arrangements for RF electrodes.

[0048] Figures 5A-5C Various views of the distal end of the electrosurgical device according to this disclosure are shown, illustrating various arrangements for RF electrodes.

[0049] Figures 6A-6D A method for forming a pericardial puncture and approaching the pericardial space according to the present disclosure is shown.

[0050] While this disclosure is applicable to various modifications and alternatives, specific embodiments have been shown by way of example in the accompanying drawings and are described in detail below. However, it is not intended to limit this disclosure to the specific embodiments described. Rather, this disclosure is intended to cover all modifications, equivalents, and alternatives that fall within the scope of this disclosure as defined by the appended claims. Detailed Implementation

[0051] To facilitate understanding of the principles of this disclosure, reference is now made to the examples illustrated in the accompanying drawings, which are described below. The illustrative examples disclosed herein are not intended to be exhaustive or to limit this disclosure to the precise forms disclosed in the following detailed description. Rather, these exemplary embodiments were chosen and described so that others skilled in the art may use their teachings. Applying multiple (e.g., all) features from a given example to all examples will not exceed the scope of this disclosure. Therefore, no single drawing should be construed as having any dependence on or requirement for any individual component or combination of components shown therein. Furthermore, in the examples, various components depicted in a given figure may be integrated with various components in other components depicted therein (and / or components not shown), all of which are considered to fall within the scope of this disclosure.

[0052] Diagnosing and treating various arrhythmias and other conditions requires a minimally invasive approach to the pericardial space. This approach can be established via a subxiphoid approach using a large-diameter (e.g., approximately 17 Ga) Tuohy needle. A guidewire (e.g., approximately 0.032 inches (approximately 0.81 mm) in outer diameter) is then advanced through the needle lumen into the heart. After obtaining access to the pericardial space, the operator removes the Tuohy needle and then advances and secures a sheath (e.g., 8.5 Fr) to facilitate the use of therapeutic devices such as ablation and mapping catheters.

[0053] As stated above, the use of large-bore needles for mechanical punctures is associated with a high incidence of clinical complications. While rigid needles offer some stability and tactile feedback to the user, unintended tissue damage can occur if the needle accidentally punctures or tears tissue.

[0054] Due to the challenges and uncertainties of using mechanical puncture to access the pericardial space, clinicians may resort to conventional endocardial ablation in cases where epicardial ablation is the preferred treatment, such as ventricular tachycardia. New devices or methods to improve the safety and predictability of access to the pericardial space would be beneficial.

[0055] In the epicardial approach, an electrosurgical probe can be advanced through the pleural cavity to reach the pericardial sac surrounding the heart. This is adjacent to the cardiac muscle (i.e., the outer surface) of the heart. By increasing the surface area of ​​the non-conductive elements around the electrode, the amount of force applied to the cutting surface of the electrode is effectively reduced. This results in cutting only the target tissue in direct contact with the electrode, while preventing the electrode from inadvertently advancing due to the "release" of accumulated force. The large surface area of ​​the material around the electrode prevents the electrode from advancing through the tissue, regardless of the pressure applied by the user to the device. This allows for the vaporization of only the tissue around the electrode by preventing the electrode from advancing beyond the target tissue.

[0056] Figure 1 This is a perspective view of an electrosurgical device 10 for discretely cutting tissue according to an embodiment of the present disclosure. In one aspect, the electrosurgical device 10 is configured to discretely cut target tissue adjacent to non-target tissue. The target tissue may include any tissue located in the body that is desired to be cut, sliced, punctured, perforated, or otherwise modified. The electrosurgical device 10 includes an elongated shaft 12 having a proximal portion 14 including a proximal end 16 and a distal portion 18 including a distal end 20.

[0057] In one embodiment, the elongated shaft 12 is formed of an insulating material. The insulating material may include a polymeric material or a ceramic material. For example, polymeric materials may include polyetheretherketone, epoxy resin, polyurethane, or parylene. Ceramic materials may be deposited, fired, molded, and / or machined. In another embodiment, the elongated shaft 12 is formed of a conductive material, such as MP35N, Elgiloy, MP35N LT, platinum alloys, stainless steel alloys, palladium alloys, and titanium. In this configuration, an insulating sheath or coating 26 surrounds the conductive shaft 12.

[0058] The electrosurgical device 10 includes at least one RF electrode 22. The at least one RF electrode 22 is configured to cut target tissue by applying RF energy to the tissue. The at least one RF electrode 22 is located on and electrically insulated from the distal portion 18 of the elongated shaft 12. In some embodiments, the distal portion 18 includes a tapered segment 24 whose diameter decreases toward the distal end 20. This allows the electrosurgical device 10 to act as an expander to stretch or expand a puncture, slice, or incision formed by the at least one RF electrode 22. The at least one electrode 22 may take the form of a long, thin electrode positioned along a portion of the length of the distal portion 18.

[0059] At least one electrode 22 is configured to vaporize tissue when RF energy is applied to the electrode, thereby forming a puncture site, section, or incision within the tissue. The proximal portion 14 of the elongated shaft 12 includes a connector 28 configured to electrically connect the electrosurgical device 10 to a control system for controlling the delivery of RF energy to at least one electrode 22.

[0060] At least one RF electrode 22 extends longitudinally along the outer surface of the distal portion 18 and has a surface area significantly smaller than the surface area of ​​the distal portion 18 adjacent to the elongated axis 12. For example, at least one RF electrode 22 has a surface area smaller than 1.0 mm. 2 Smaller surface area. The significantly larger surface area of ​​the distal portion 18 reduces movement of the distal portion 18 into the incision or puncture site formed in the target tissue. This configuration prevents at least one RF electrode 22 and the distal portion 18 from unintentionally penetrating any tissue directly adjacent to the target tissue.

[0061] Lumen 30 extends from the proximal end 16 of the elongated shaft 12 to the distal end 20 of the elongated shaft 12. In one aspect, lumen 30 extends through connector 28. Lumen 30 is configured to introduce fluid or a medical device into the electrosurgical device 10 for delivery from the distal end 20. For example, contrast agent may be delivered from the distal end 20, or a guidewire may extend from lumen 30.

[0062] Figure 2 This is a perspective view of an electrosurgical device 110 for discrete tissue cutting according to an embodiment of the present disclosure. The electrosurgical device 110 includes an elongated shaft 112 having a proximal portion 114 including a proximal end 116 and a distal portion 118 including a distal end 120. The distal portion 118 includes a substantially uniform diameter. The distal end 120 includes a distal surface 121. As discussed above, the elongated shaft 112 may be formed of an insulating or conductive material covered in an insulating coating or sheath.

[0063] The electrosurgical device 110 includes at least one RF electrode 122 located on a distal portion 118 of an elongated shaft 112. The at least one RF electrode 122 is electrically insulated from the distal portion 118. The at least one RF electrode 122 includes a first electrode 123 located on a distal side 121 and a second electrode 124 and a third electrode 125 located on the outer surface of the distal portion 118.

[0064] Each of the first electrode 123, the second electrode 124, and the third electrode 125 has a significantly smaller surface area than the portion of the elongated shaft 112 adjacent to the electrode. After an incision or puncture site is formed by applying energy to any of the first electrode 123, the second electrode 124, and the third electrode 125, the significantly larger surface area of ​​the adjacent portion prevents the distal portion 118 from moving into the incision or puncture site formed in the target tissue. In one aspect, RF energy can be delivered independently to each of the first electrode 123, the second electrode 124, or the third electrode 125. Therefore, the user can select which electrode to actuate to perform different parts of the procedure. In another aspect, RF energy can be delivered simultaneously to each of the first electrode 123, the second electrode 124, or the third electrode 125.

[0065] The first electrode 123 is positioned across the distal side 121 and intersects the center of the distal side 121. In some embodiments, the first electrode 123 rests in a plane shared with the second electrode 124 and the third electrode 125. In some embodiments, the first electrode 123 rests in a plane orthogonal to or offset from the plane where the second electrode 124 and the third electrode 125 are located. In some embodiments, the first electrode is positioned across the distal side 121, offset from the center of the distal side.

[0066] The second electrode 124 and the third electrode 125 extend longitudinally along the outer surface of the distal portion 118, parallel to or adjacent to the longitudinal axis 130 of the elongated shaft 112. In some embodiments, more than two electrodes are positioned along the distal portion 118. Additionally, in some embodiments, the second electrode 124, the third electrode 125, or both the second electrode 124 and the third electrode 125 extend through the outer surface of the distal portion 118, offset from or orthogonal to the longitudinal axis 130 of the elongated shaft 112.

[0067] Figures 3A-3EVarious cross-sections of a metal wire, filament, or conductor forming at least one RF electrode 22, 122 according to the present disclosure are shown. The metal wire, filament, or conductor forming at least one RF electrode 22, 122 may include various cross-sections and may be formed of a conductive material. In some embodiments, the metal wire or conductor may include copper, MP35N, Elgiloy, MP35N LT, platinum alloy, stainless steel alloy, palladium alloy, titanium, and combinations thereof. In some embodiments, the metal wire, filament, or conductor may include a non-transparent conductive material. The metal wire, filament, or conductor is configured to lie on the surface of an elongated shaft 12, 112 to form at least one RF electrode 22, 122. In one aspect, the metal wire, filament, or conductor forms at least one RF electrode 22, 122 and extends from at least one RF electrode 22, 122 to a connector 28, 128. In another aspect, a separate conductive metal wire or conductor extends from at least one RF electrode 22, 122 to the connector 28, 128.

[0068] Figure 3A A metal wire, filament, or conductor is shown forming at least one RF electrode 22, 122 having a rectangular cross-section. The rectangular cross-section includes a first pair of surfaces 40 orthogonal to the second pair of surfaces 42. Figure 3B A metal wire, filament, or conductor is shown forming at least one RF electrode 22, 122 having an elliptical cross-section. The elliptical cross-section includes a single surface 44. Figure 3C A metal wire, filament, or conductor is shown forming at least one RF electrode 22, 122 having a circular cross-section. Similar to an elliptical cross-section, the circular cross-section includes a single surface 44. Figure 3D A metal wire, filament, or conductor is shown forming at least one RF electrode 22, 122 having a dome-shaped cross-section. The dome-shaped cross-section includes a curved surface 46 and a first pair of parallel surfaces 48 orthogonal to a flat surface 50 opposite to the curved surface 46. Figure 3E A metal wire, filament, or conductor is shown forming at least one RF electrode 22, 122 having a polygonal cross-section. The polygonal cross-section includes a pair of parallel surfaces 52 intersecting a first angled surface 54 and a second angled surface 56.

[0069] Figures 4A-4C Various cross-sectional views of the electrosurgical devices 10, 110 according to this disclosure are shown, illustrating various arrangements for at least one RF electrode 22, 122. Figure 4AIn this configuration, at least one RF electrode 22, 122 is mounted to the outer surface of the elongated shafts 12, 112. As can be seen, the surface area of ​​at least one RF electrode 22, 122 is significantly smaller than the surrounding surface area of ​​the elongated shafts 12, 112. This allows at least one RF electrode 22, 122 to form a puncture or incision in the target tissue without any portion of the elongated shafts 12, 112 being completely pressed into the puncture or incision. This protects non-target tissue adjacent to the target tissue. Figure 4A An example of a wire conduit 60 is shown, configured to receive a wire 62 for electrically connecting at least one RF electrode 22, 122 to a control system. The wire 62 extends proximally from the at least one RF electrode 22, 122, through the wire conduit 60, to the proximal ends 16, 116 of the elongated shafts 12, 122, reaching connectors 28, 128. In some aspects, the wire 62 is the same metal wire or filament forming the at least one RF electrode 22, 122. Therefore, the wire 62 has the same cross-section as the at least one RF electrode 22, 122. In some aspects, the wire 62 is a different metal wire or filament from the metal wire or filament forming the at least one RF electrode 22, 122.

[0070] exist Figure 4B In this arrangement, at least one RF electrode 22, 122 is partially embedded in the elongated shaft 12, 112 of the electrosurgical device 10, 110. In this arrangement, at least one RF electrode 22, 122 has portions extending partially above (at 64) and partially below (at 66) the outer surface of the elongated member 12. At least one RF electrode 22, 122 may be partially positioned in a groove or channel located on the outer surface of the elongated shaft 12, 112.

[0071] exist Figure 4C In this arrangement, at least one RF electrode 22, 122 is completely positioned within a channel or groove 68 on an elongated member of the electrosurgical device 10, 110. In this arrangement, at least one RF electrode 22, 122 remains completely below the outer surface of the elongated member 12, 112. In this arrangement, tissue must partially enter the channel or groove 68 to be punctured or cut by at least one RF electrode 22, 122.

[0072] Figures 5A-5C Various plan views of the distal side 121 of the electrosurgical device 110 according to this disclosure are shown, illustrating various arrangements for at least one RF electrode 122. Figure 5AIn the device, at least one RF electrode 122 is positioned at the center of the distal side 121. The at least one RF electrode 122 is formed from a portion of an exposed metal wire, filament, or conductor having a circular cross-section. The at least one RF electrode 122 has a significantly smaller surface area than the surface area of ​​the distal side 121 surrounding it. The distal side 121 is insulating or non-conductive, such that the at least one RF electrode 122 is the only part of the electrosurgical device 110 that forms an incision or puncture site in the tissue. The larger surface area of ​​the distal side 121 prevents the electrosurgical device 110 from entering the incision or puncture site formed by the at least one RF electrode 122.

[0073] exist Figure 5B In this device, at least one RF electrode 122 is positioned such that it spans the distal side 121 along its central axis 119. The at least one RF electrode 122 has a surface area significantly smaller than that of the distal side 121. The distal side 121 is insulating or non-conductive, such that the at least one RF electrode 122 is the only part of the electrosurgical device 110 that forms an incision or puncture site in the tissue. The larger surface area of ​​the distal side 121 prevents the electrosurgical device 110 from entering the incision or puncture site formed by the at least one RF electrode 122.

[0074] exist Figure 5C In this embodiment, at least one RF electrode 122 includes a plurality of RF electrodes 124, 125, 126 uniformly positioned around the center of a distal surface 121. The plurality of RF electrodes 124, 125, 126 have a combined surface area significantly smaller than the surface area of ​​the distal surface 121. The distal surface 121 is insulating or non-conductive, such that the only portion of the electrosurgical device 110 forming an incision or puncture site in tissue is the plurality of RF electrodes 124, 125, 126. The larger surface area of ​​the distal surface 121 prevents the electrosurgical device 110 from entering the incision or puncture site formed by the plurality of RF electrodes 124, 125, 126. Although three RF electrodes 124, 125, 126 are shown, it should be understood that more or fewer RF electrodes may be used, provided that the combined surface area of ​​the electrodes is smaller than the surface area of ​​the adjacent electrodes to prevent the electrosurgical device 110 from entering the incision or puncture site.

[0075] Figures 6A-6D A method for forming a pericardial puncture and approaching the pericardial space according to this disclosure is shown. Figure 6AIn this embodiment, an electrosurgical device 210 having at least one RF electrode 222 is introduced into the body and positioned adjacent to the heart 230. At least one RF electrode 222 is positioned on the distal portion 218 of an elongated shaft 212. At least one RF electrode 222 is configured to have a surface area much smaller than the surface area of ​​the distal portion 218 adjacent to the at least one RF electrode. At least one RF electrode 222 is a long electrode extending along a tapered portion 224 of the distal portion 218.

[0076] exist Figure 6A In this embodiment, the electrosurgical device 210 is moved toward the heart 230. The heart 230 includes a pericardium 240 and a myocardium 242. The pericardium 240 and the myocardium 242 are separated by a pericardial space 244. In one aspect, pressing the electrosurgical device 210 into the heart 230 places the RF electrode 222 against the surface of the heart 230 and causes both the pericardium 240 and the myocardium 242 to bulge. The pericardium 240 is the target tissue, i.e., the tissue from which a puncture site or incision is to be formed, while the myocardium 242 is a non-target tissue.

[0077] On the other hand, such as Figure 6B As shown, a mechanical device (such as a hook, snare, or barb 231) can be used to pull the pericardium 240 toward the RF electrode 220, which can be advanced through the lumen of the electrosurgical device 210. The hook, snare, or barb 231 can capture the pericardium 240 and pull it toward the RF electrode 220. In some aspects, the hook, snare, or barb 231 can be mounted on the surface of the electrosurgical device 210. The hook, snare, or barb 231 may include shape memory properties and move from a first configuration to a second configuration to pull tissue toward the RF electrode. In another aspect, suction can be used to pull the pericardium 240 toward the RF electrode 220. For example, the electrosurgical device 210 may include one or more holes 233 adjacent to the RF electrode 220. One or more holes 233 communicate with a suction source through one or more lumens 235 extending toward the proximal end of the electrosurgical device 210.

[0078] exist Figure 6CIn this process, RF energy is applied to at least one RF electrode 222. In one aspect, the energy is applied in pulses for 1 second. In another aspect, the energy is applied in pulses of 300 ms using, for example, a 1-second pulse pattern (30% duty cycle). Applying energy to at least one RF electrode 222 creates a slit, puncture site, or incision 250 in the pericardium 240. A portion of the distal portion 218 prolapses into the pericardial space 244 through the slit, puncture site, or incision 250. However, the surface area surrounding the distal portion 218 of at least one RF electrode 222 prevents the electrosurgical device 210 from "piercing" in the direction of the force applied to the tissue. Therefore, at least one RF electrode 222 is prevented from slicing, cutting, or puncturing the myocardium 242, thereby allowing the device to be introduced into the pericardial space 244 without damaging adjacent non-target tissue.

[0079] like Figure 6C As shown, the mechanical guidewire 252 extending from the distal end of the electrosurgical device 210 is flexible, preventing it from puncturing the pericardium 240 and causing it to deviate from the pericardium 240. Therefore, if the electrosurgical device 210 is advanced at an angle toward the heart 230, the extended guidewire 252 will deviate from the pericardium 240. To obtain access to the pericardial space 244, the guidewire 252 must enter the slit, puncture site, or incision 250 formed by the RF electrode 222. After entering the slit, puncture site, or incision 250, the guidewire 252 is axially aligned with the electrosurgical device 210. In one aspect, the guidewire 252 is formed of 038 stainless steel or 005 NiTi.

[0080] exist Figure 6D In this process, a mechanical guidewire 252 passes through the electrosurgical device 210 into the pericardial space 244. Introducing the guidewire 252 into the pericardial space 244 confirms that an access to the pericardial space 244 has been established. The electrosurgical device 210 is then advanced along the guidewire 252, such that the tapered portion 224 can dilate the incision or puncture site to allow for the introduction of larger medical devices if needed. In some respects, fluids (such as contrast agents) can be introduced into the pericardial space 244 through the electrosurgical device 210.

[0081] It is readily understood that the inclusion of one or more steps, and the order in which they are listed, are not limitations on the claims unless expressly or implicitly stated otherwise in the specification or the claims themselves. It is also readily understood that the illustrated methods are merely examples among the many disclosed examples, and certain steps may be added or omitted without departing from the scope of this disclosure. Such steps may include combining apparatus, systems, or methods or components thereof, as well as conventional and traditional elements well understood in the art.

[0082] The connecting lines shown in the various figures contained herein are intended to represent exemplary functional relationships and / or physical connections between various elements. It should be noted that many alternative or additional functional relationships or physical connections may exist in actual systems. However, benefits, advantages, solutions to problems, and any elements that may bring about or make more significant any benefit, advantage, or solution should not be construed as critical, essential, or necessary features or elements. Therefore, the scope of the invention is not limited in any way except as expressly stated in the appended claims, and references to elements in the singular form are not intended to mean "one and only one," but rather "one or more." Furthermore, the use of phrases such as "at least one of A, B, or C" in the claims is intended to be interpreted as meaning that A may exist alone in one embodiment, B may exist alone in one embodiment, C may exist alone in one embodiment, or any combination of elements A, B, or C (e.g., A and B, A and C, B and C, or A and B and C) may exist in a single embodiment. The terms “couples”, “connection”, “attachment” and their variations are used to include two arrangements in which two or more components are in direct physical contact, and in which two or more components are not in direct contact with each other (e.g., the components are “coupled” via at least one third component), but still, for example, cooperate or interact.

[0083] In the detailed description herein, references to "an embodiment," "embodiment," "exemplary embodiment," etc., indicate that the described embodiment may include a particular feature, structure, or characteristic, but each embodiment may not necessarily include that particular feature, structure, or characteristic. Furthermore, such phrases do not necessarily refer to the same embodiment. Moreover, when a particular feature, structure, or characteristic is described in connection with an embodiment, it should be understood that in conjunction with other embodiments, affecting such feature, structure, or characteristic is within the knowledge of those skilled in the art who benefit from this disclosure, whether explicitly described or not. After reading the description, it will be clear to those skilled in the art how to implement this disclosure in alternative embodiments.

[0084] Various modifications and additions may be made to the exemplary embodiments discussed without departing from the scope of this disclosure. For example, while the above embodiments relate to specific features, the scope of this disclosure also includes embodiments with different combinations of features and embodiments that do not include all of the stated features. Therefore, the scope of this disclosure is intended to cover all such alternatives, modifications, and variations, and all equivalents thereof, falling within the scope of the claims.

Claims

1. An electrosurgical device for discretely cutting target tissue adjacent to non-target tissue, the electrosurgical device comprising: An elongated shaft having a proximal portion including a proximal end and a distal portion including a distal end; as well as At least one electrode configured to cut the target tissue, the at least one electrode having a surface area and located on the distal portion; The distal portion is electrically insulated from the at least one electrode and has a surface area significantly larger than that of the at least one electrode. The distal portion is configured to prevent it from moving into an incision or puncture site formed in the target tissue by applying energy to the at least one electrode.

2. The electrosurgical device according to claim 1, wherein, The elongated shaft includes a lumen extending from the proximal end to the distal end.

3. The electrosurgical device according to any one of claims 1 or 2, wherein, The at least one electrode is formed of a metal wire having one or more rectangular, circular, elliptical, square or polygonal cross-sections.

4. The electrosurgical device according to any one of claims 1-3, wherein, The at least one electrode is formed of a conductive metal.

5. The electrosurgical device according to any one of claims 1-4, further comprising at least one wire configured to electrically connect the at least one electrode to a control system.

6. The electrosurgical device according to claim 5, wherein, The at least one wire extends proximally from the at least one electrode through the wire lumen to the proximal end of the elongated shaft.

7. The electrosurgical device according to claim 5, wherein, The at least one wire forms the at least one electrode.

8. The electrosurgical device according to any one of claims 1-7, further comprising a connector located at the proximal end, the connector being configured to electrically connect the electrosurgical device to a control system.

9. The electrosurgical device according to any one of claims 1-8, wherein, The at least one electrode extends longitudinally along the outer surface of the distal portion.

10. The electrosurgical device according to claim 9, wherein, The outer surface tapers towards the distal end in a tapering shape.

11. The electrosurgical device according to any one of claims 1-10, wherein, The at least one electrode is located in a recess or groove along the distal portion.

12. The electrosurgical device according to any one of claims 1-11, wherein, The at least one electrode extends along the longitudinal axis of the elongated shaft.

13. The electrosurgical device according to any one of claims 1-12, wherein, The at least one electrode has a ratio of 1.0 mm. 2 Smaller surface area.

14. The electrosurgical device according to any one of claims 1-13, wherein, The at least one electrode is located on the distal side of the elongated shaft.

15. The electrosurgical device according to any one of claims 1-14, wherein, The at least one electrode includes multiple electrodes.

16. An electrosurgical device for discretely cutting the pericardium adjacent to the myocardium, the electrosurgical device comprising: An elongated shaft having a proximal portion including a proximal end and a distal portion including a distal end; as well as At least one electrode configured to cut the pericardium, the at least one electrode having a surface area and located on the distal portion; The distal portion is electrically insulated from the at least one electrode and has a surface area significantly larger than that of the at least one electrode. The distal portion is configured to prevent it from moving into an incision or puncture site formed in the pericardium by applying energy to the at least one electrode.

17. The electrosurgical device according to claim 16, wherein, The elongated shaft includes a lumen extending from the proximal end to the distal end.

18. The electrosurgical device according to claim 16, wherein, The at least one electrode is formed of a metal wire having one or more rectangular, circular, elliptical, square or polygonal cross-sections.

19. The electrosurgical device according to claim 16, wherein, The at least one electrode is formed of a conductive metal.

20. The electrosurgical device of claim 16, further comprising at least one wire configured to electrically connect the at least one electrode to a control system.

21. The electrosurgical device according to claim 20, wherein, The at least one wire extends proximally from the at least one electrode through the wire lumen to the proximal end of the elongated shaft.

22. The electrosurgical device according to claim 20, wherein, The at least one wire forms the at least one electrode.

23. The electrosurgical device of claim 16, further comprising a connector located at the proximal end, the connector being configured to electrically connect the electrosurgical device to a control system.

24. The electrosurgical device according to claim 16, wherein, The at least one electrode extends longitudinally along the outer surface of the distal portion.

25. The electrosurgical device according to claim 24, wherein, The outer surface tapers towards the distal end in a tapering shape.

26. The electrosurgical device according to claim 16, wherein, The at least one electrode is located in a recess or groove along the distal portion.

27. The electrosurgical device according to claim 16, wherein, The at least one electrode has a ratio of 1.0 mm. 2 Smaller surface area.

28. The electrosurgical device according to claim 16, wherein, The at least one electrode is located on the distal side of the elongated shaft.

29. The electrosurgical device according to claim 16, wherein, The at least one electrode includes multiple electrodes.

30. An electrosurgical device for discretely cutting the pericardium adjacent to the myocardium, the electrosurgical device comprising: An elongated shaft having a proximal portion including a proximal end and a tapered distal portion including a distal end; as well as At least one electrode configured to cut the pericardium, the at least one electrode having a surface area and extending longitudinally along the outer surface of the distal portion; The distal portion is electrically insulated from the at least one electrode and has a surface area significantly larger than that of the at least one electrode. The distal portion is configured to prevent it from moving into an incision or puncture site formed in the pericardium by applying energy to the at least one electrode.

31. A method for discretely cutting target tissue using radio frequency energy, the method comprising: An electrosurgical device is provided, the electrosurgical device comprising: An elongated shaft having a proximal portion including a proximal end and a distal portion including a distal end; and At least one electrode configured to cut the target tissue, the at least one electrode having a surface area and extending longitudinally along the outer surface of the distal portion; The distal portion is electrically insulated from the at least one electrode and has a surface area that is significantly larger than that of the at least one electrode. The electrosurgical device is advanced to the target location within the patient's body; and Provide radio frequency energy to the at least one electrode and form an incision in the target tissue; The distal portion contacts tissue adjacent to the incision to prevent the distal portion from moving into the incision.

32. The method according to claim 31, wherein, The distal portion tapers towards the distal end in a tapering shape.

33. The method according to claim 31, wherein, The elongated shaft includes a lumen extending from the proximal end to the distal end.

34. The method according to claim 31, wherein, The target tissue is the pericardium.

35. The method of claim 34, further comprising advancing the guidewire through the incision and into the pericardial space.

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