Adjustable electrosurgical knife with apical electrode

Abstract

An electrosurgical device comprises a sheath, an electrode extending from the sheath, the electrode comprising a cross-sectional profile having a multi-apical cross-sectional shape, an insulator disk positioned over the electrode distally of the sheath, and an actuator connected to the insulator disk to move the insulator disk along the electrode. A method for performing a surgical procedure on tissue comprising inserting an insertion sheath into anatomy to position an electrode proximate to target tissue, adjusting an insulator disk connected to the electrode to adjust a distance between a distal-most face of the electrode and the insulator disk, and energizing the electrode to cut the target tissue.

Description

ADJUSTABLE ELECTROSURGICAL KNIFE WITH APICAL ELECTRODEPRIORITY CLAIM

[0001] This application claims the benefit of priority of U.S. Provisional Patent Application Serial No. 63 / 553,751, filed February 15, 2024, and U.S. Provisional Patent Application Serial No. 63 / 599,643, filed November 16, 2023, the contents of which are incorporated herein by reference.TECHNICAL FIELD

[0002] The present disclosure relates generally to medical devices comprising elongate bodies configured to be inserted into incisions or openings in anatomy of a patient to provide cutting capabilities for tissue.

[0003] More specifically, the present disclosure relates to medical devices, such as electrosurgical knives, having exposed electrodes that extend from a catheter to provide cutting capabilities.BACKGROUND

[0004] Electric scalpels or knives are widely used in surgery. The electric knife can be connected to a generator that can generate a high-frequency current. The electrosurgical knife can be connected to a counter electrode plate that can be put in contact with living tissue of a body and a treatment electrode at a tip of the electric knife that can perform incisions and coagulation on the living tissue. The counter electrode plate is configured to have a large contact area with the living body in order to reduce the current density. However, since the treatment electrode is thin, the current density is high. Therefore, loule heat is generated between the living body and the treatment electrode, and the heat causes the moisture in the cells to evaporate rapidly, so that the living tissue is incised, and the cut surfaces of the tissue are thermally solidified or cauterized. As described above, the characteristic feature of the electric scalpel is that it can perform an incision accompanied by hemostasis.SUMMARY

[0005] In some contexts, electrosurgical knives are used with endoscope systems where an endoscope is inserted into a patient to reach anatomy deep inside the patient. For example,electrosurgical knives can be used to treat reproductive organs reached via insertion into the esophagus. The electrosurgical knife is delivered to the anatomy through a lumen within the endoscope. Thus, the electrosurgical knife must typically be small in cross-sectional area to operate within the lumen of the endoscope. Typical electrosurgical knives comprise a sheath or catheter through which an electrode wire extends. The tip of the electrode wire can be extended from the sheath to perform treatment of tissue.

[0006] The present disclosure recognizes that problems to be solved with conventional electrosurgical knives include, among other things, A) fluid injection located along the side of the electrode, which can require withdrawal of the electrode to inject fluid; B) the inability to adjust a cut length of the electrode; and C) the requirement to use multiple electrosurgical knives if an insulated tip is needed. Regarding A), fluid injection systems can involve the injection of fluid from the distal end of the sheath of the electrosurgical knife. Fluid can be injected into the sheath of the electrosurgical knife to flow down the sheath alongside the outside of the electrode. However, in order to accurately eject the fluid, the tip of the electrode is typically retracted into the sheath to allow the fluid to escape. Such retraction of the electrode tip can be an inconvenience while performing the procedure. For example, the tip of the electrode needs to be relocated relative to the anatomy after irrigation. Regarding B), the electrode wire is typically configured to extend from the sheath a fixed amount, such as by being fully retracted or fully extended. The length that the tip is configured to extend can be adequate to perform a wide range of procedures but not all procedures. For example, some procedures benefit from performing cuts with different cut depths. It is difficult for a surgeon to attempt to manually perform a cut that is shorter than the length that the electrode extends from the sheath. These procedures thus require the use of multiple electrosurgical knives having different cutting lengths. Regarding C), typical electrosurgical instruments are either configured to have an insulated tip or not. An insulated tip can prevent the distal-most end of the electrode from contacting tissue, thereby facilitating cutting along the length of the electrode but not at the tip. Thus, in order to use both configurations, it is necessary to withdrawn one instrument to insert the other.

[0007] The present disclosure can provide solutions to these and other problems by providing an electrosurgical knife that includes: A) a fluid injection passage located within, e.g., at the center, of the electrode that can inject fluid without retracting the electrode; B) a moveable insulating disk that can slide along the electrode to change the effective cutting length of the electrode and thereby control cutting depth; and C) a moveable insulating disk that can be slid along the electrode to form an insulated tip and prevent the tip of the electrode fromcontacting tissue. The insulating disk can be used without increasing the overall outer diameter of the instrument or increasing the cutting diameter of the device regardless of the position of the insulating disk. The electrosurgical knives of the present disclosure can facilitate such features by having a star-shaped or multi-pointed cutting electrode that can have an enlarged cross-sectional area to accommodate an internal fluid passage. The tips of the star-shaped electrode can provide cutting in multiple directions along an edge similar to that of an electrode wire. The star-shaped cross-sectional profile of the electrode and the insulating disk can facilitate sliding and stability of the insulating disk. Furthermore, the electrodes and other components of the present disclosure can include various coatings to prevent or inhibit tissue from adhering to the electrode.

[0008] In an example, an electrosurgical device can comprise a sheath, an electrode extending from the sheath, the electrode comprising a cross-sectional profile having a multi- apical cross-sectional shape, an insulator disk positioned over the electrode distally of the sheath, and an actuator connected to the insulator disk to move the insulator disk along the electrode.

[0009] In another example, a method for performing a surgical procedure on tissue can comprise inserting an insertion sheath into anatomy to position an electrode proximate to target tissue, adjusting an insulator disk connected to the electrode to adjust a distance between a distal-most face of the electrode and the insulator disk, and energizing the electrode to cut the target tissue.BRIEF DESCRIPTION OF DRAWINGS

[0010] FIG. l is a schematic diagram of an electrosurgical knife system suitable for use with the present disclosure.

[0011] FIG. 2 is a schematic front cross-sectional view of a body of a patient showing an electrosurgical treatment device inserted into an endoscope extending into anatomy of the patient to reach target anatomy.

[0012] FIG. 3 is a schematic perspective view of an electrosurgical treatment device extending from an endoscope to interact with target anatomy.

[0013] FIG. 4 is a schematic perspective view of an electrosurgical device of the present disclosure comprising a sheath, a star-shaped electrode, an actuator comprising push rods and an insulated disk.

[0014] FIG. 5 is a perspective exploded view of the electrosurgical device of FIG. 4.

[0015] FIG. 6 is an end view of the electrosurgical device of FIG. 4.

[0016] FIG. 7 is a schematic cross-sectional view of a distal end portion of the electrosurgical device of the present disclosure showing an actuator, a control wire and a fluid tube.

[0017] FIG. 8 is a plan view of the electrosurgical device of FIG. 4 through FIG. 7 showing a control handle.

[0018] FIG. 9 is a plan view of the control handle of FIG. 8 showing an actuation mechanism, a locking system and a fluid inlet.

[0019] FIG. 10 is a perspective view of a portion of the locking system of FIG. 9 showing a stopper connected to an actuator for an insulating disk of the present disclosure.

[0020] FIG. 11 A is a schematic cross-sectional view of the stopper of FIG. 10 within a locking knob such that the stopper cannot pass through the locking knob.

[0021] FIG. 1 IB is a schematic cross-sectional view of the stopper of FIG. 10 within a locking knob such that the stopper can pass through the locking knob.

[0022] FIG. 12A is a schematic diagram of an electrosurgical device of the present disclosure with an insulated disk in an advanced state around a star-shaped electrode.

[0023] FIG. 12B is a schematic diagram of an electrosurgical device of the present disclosure with an insulated disk in an intermediate state around a star-shaped electrode.

[0024] FIG. 12C is a schematic diagram of an electrosurgical device of the present disclosure with an insulated disk in a retracted state around a star-shaped electrode.

[0025] FIG. 13 is a block diagram illustrating operations of methods for performing a surgical procedure using an electrosurgical device of the present disclosure.

[0026] FIG. 14 is an end view an electrode for an electrosurgical device of the present disclosure wherein the electrode does not include a central irrigation channel.

[0027] FIG. 15 is an end view of an electrode for an electrosurgical device of the present disclosure comprising a four-pointed star.

[0028] FIG. 16 is an end view of an electrode for an electrosurgical device of the present disclosure comprising a four-pointed square.

[0029] FIG. 17 is a perspective view of an electrode and an insulting disk for an electrosurgical device of the present disclosure comprising a multi-lobed body.

[0030] FIG. 18A is a perspective view of the electrode of FIG. 17 showing the insulating disk at a distal location.

[0031] FIG. 18B is a perspective view of the electrode of FIG. 17 showing the insulating disk at an intermediate location.

[0032] FIG. 18C is a perspective view of the electrode of FIG. 17 showing the insulating disk at a proximal location.DETAILED DESCRIPTION

[0033] FIG. l is a schematic diagram showing a configuration of an electrosurgical treatment device suitable for use with the present disclosure. Treatment device 11 can include handpiece 12, power source unit 13, and cable 14 connecting handpiece 12 and power source unit 13. Handpiece 12 can include holding portion 15 that forms an outer shell, a vibration generation section (transducer) contained in holding portion 15, probe 17 connected to the vibration generation section, and sheath 18 that covers the periphery of probe 17 to protect probe 17. Holding portion 15 is connected to one end of cable 14. The other end of cable 14 is connected to power source unit 13. Holding portion 15 can be, for example, cylindrical.

[0034] Holding portion 15 is provided with energy operation input button 21. A doctor can operate energy operation input button 21 and can thereby apply energy (e.g., ultrasonic vibration and a high-frequency current), via probe 17, to body tissue to be treated.

[0035] Probe 17 can be formed into a rod of, for example, a biocompatible metallic material (such as titanium alloy). Ultrasonic vibration is conveyed to probe 17 from the vibration generation section, and a high-frequency current is supplied to probe 17 from the high- frequency current supply section 28. Therefore, probe 17 not only applies ultrasonic vibration to body tissue, but also functions as a first electrode (active electrode) of a monopolar-type electrosurgical knife. Treatment device 11 of the present disclosure can have a return electrode (not shown) that functions as a second electrode of the monopolar-type electrosurgical knife. The return electrode can be connected to high-frequency current supply section 28 via an electric line, and is provided in a position where the return electrode contacts a patient outside the body of the patient at the time of surgery. One of the two directions parallel to the longitudinal axis C of probe 17 is defined as a distal direction Cl, and the opposite direction to the distal direction is defined as a proximal direction C2 (see FIG. 1).

[0036] The distal end part of probe 17 protrudes from the distal end of sheath 18. Namely, sheath 18 can comprise a cylindrical body that covers a middle part of probe 17 and the proximal end part opposite to the distal end part of probe 17.

[0037] Power source unit 13 includes ultrasonic current supply section 26, high-frequency current supply section 28 and energy control section 43 that controls ultrasonic current supply section 26 and high-frequency current supply section 28. Energy control section 43 can control supply of an ultrasonic wave generation current from ultrasonic current supply section 26 and supply of a high-frequency current from high-frequency current supply section 28.Ultrasonic current supply section 26 and high-frequency current supply section 28 are examples of the energy generation section. When a doctor operates energy operation input button 21 (switch), an electrical signal is conveyed to energy control section 43, and an input of an energy operation is detected. Accordingly, energy control section 43 supplies an ultrasonic wave generation current from the ultrasonic current supply section 26 to the probe 17, and supplies a high-frequency current from high-frequency current supply section 28 to probe 17.

[0038] A doctor can operate energy operation input button 21 with probe 17 brought into contact with body tissue. In this state, the probe makes ultrasonic vibration, and applies a thermal energy of frictional motion to body tissue. Simultaneously, a high-frequency current flows from probe 17 to body tissue, and an electrical energy can be thereby applied to the body tissue. Since two types of energies are applied from probe 17, body tissue brought into contact with probe 17 can be efficiently incised, and its peripheral tissue can be efficiently coagulated. In examples, only one type of energy can be used.

[0039] A doctor can coagulate body tissue by operating energy operation input button 21 with probe 17 brought into contact with the body tissue. Accordingly, flow of blood from the tissue can be treated by cauterization to stanch the flow of the blood. In addition, the doctor can also incise / excise body tissue (in particular, membranous tissue, such as mesentery) by probe 17 by operating energy operation input button 21 with probe 17 brought into contact with the body tissue.

[0040] In examples, probe 17 can be configured to include features of the electrodes described below with reference to FIG. 4 - FIG. 7.

[0041] In examples, an electrosurgical knife system suitable for use with the present disclosure is described in Pat. No. US 10,368,896 B2 to Akagane titled “Treatment Device,” the entire contents of which are hereby incorporated by reference.

[0042] FIG. 2 is a schematic front cross-sectional view of body 200 of a patient showing electrosurgical treatment device 202 inserted into endoscope 204 extending into anatomy of the patient to reach target anatomy 206. Body 200 can comprise esophagus 210, stomach 212, uterus 214 and fallopian tubes 216. Electrosurgical treatment device 202 can comprise sheath 220, cutting wire 222, handle 224 and cord 226. Cord 226 can connect to energy source 228 and fluid source 229. Endoscope 204 can comprise handle 230, cable 232, port 234, insertion tube 236 and control knob 238.

[0043] FIG. 2 schematically illustrates the use of endoscope 204 to introduce electrosurgical treatment device 202 into body 200 to incise the fallopian tubes 216 of a patient with cuttingwire 222. Electrosurgical treatment device 202 can comprise treatment device 11 of FIG. 1. Furthermore, electrosurgical treatment device 202 can be configured to include electrode 304 of FIG. 4 - FIG. 7 and handle 350 of FIG. 8 - FIG. 1 IB described herein. In the illustrated example, insertion tube 236 of endoscope 204 can be inserted into the mouth (not illustrated) of the patient, through esophagus 210, into stomach 212. Incision 218 can be made in the wall of stomach 212 to allow insertion tube 236 to pass from the interior of stomach 212 into the peritoneal cavity and to approach the pelvic organs of the patient. For simplicity, only uterus 214 and fallopian tubes 216 are shown. Electrosurgical treatment device 202 can be passed through an inner working channel or lumen within insertion tube 236 connected to port 234. Sheath 220 can extend from the distal end of insertion tube 236 and cutting wire 222 can protrude from the distal end of sheath 220. Cutting wire 222 can be pressed against one of fallopian tubes 216 in order to make an incision therein. Handle 224 can be attached to the proximal end of sheath 220 to allow an operator to retract and extend cutting wire 222 into and out of sheath 220. Handle 224 can be connected to cord 226 that can supply RF current from an RF generator (e.g., energy source 228) to cutting wire 222. Handle 224 can be used to protrude and retract cutting wire 222 from the distal end of sheath 220. However, cutting wire 222 can be positioned relative to the anatomy by manipulating insertion tube 236 of endoscope 204, such as by pushing or pulling insertion tube 236 and / or operating control knob 238. Control knob 238 can be used to control movement of the distal end of insertion tube 236, such as by inducing bending in bending section 240.

[0044] FIG. 3 illustrates an enlarged view of target anatomy 206 of FIG. 2 showing one of fallopian tubes 216 extending from uterus 214. Target anatomy 206 can comprise fallopian tubes 216 positioned within intraperitoneal cavity 250 of abdomen 252 proximate other pelvic organs 254. In examples, it can be desirable to cut through a fallopian tube to severe the fallopian tube from uterus 214 during a tubal ligation procedure to prevent eggs from traveling from the ovaries into the fallopian tubes so as to render the patient infertile. FIG. 3 illustrates the distal end of insertion tube 236 of endoscope 204 having bending section 240. Bending section 240 is illustrated positioned within intraperitoneal cavity 250 of the lower abdomen of the patient. Cutting wire 222 and sheath 220 protrude from the distal end of insertion tube 236 and are positioned near one of the fallopian tubes 216 of the patient. As illustrated, cutting wire 222 can be pressed against fallopian tubes 216 as the RF current is applied to cutting wire 222. Control of the direction in which cutting wire 222 moves can be achieved by manipulation of insertion tube 236 of endoscope 204 by grasping the portion of insertion tube 236 that extends from the mouth of the patient and pushing or pulling toadvance or retract cutting wire 222, or by manipulating the angle of bending section 240 with control knob 238 on handle 230.

[0045] In examples, an electrosurgical knife system and endoscope system suitable for use with the present disclosure is described in Pat. No. US 8,715,281 B2 to Barlow et al. titled “Treatment Device for Endoscope,” the entire contents of which are hereby incorporated by reference.

[0046] FIG. 2 and FIG. 3 illustrate an example of a type of procedure, e.g., a tubal ligation, that electrosurgical treatment device 202 can be used to perform. Electrosurgical devices of the present disclosure can be used for other procedures, such as Endoscopic Submucosal Dissection (ESD) procedures. Electrosurgical devices of the present disclosure can be used in many surgical applications for cutting, coagulating, dissecting, fulgurating, ablating and shrinking tissue. Electrosurgical devices of the present disclosure can be used in many surgical settings, such as gastroenterology, general surgery, obstetrics and gynecology (Ob- Gyn), ear, nose and throat (ENT), Pulmonary Medicine, Dermatology and the like.

[0047] As illustrated in FIG. 3, in many situations, pressing cutting wire 222 against fallopian tube 216 in the direction of arrow 256, can force fallopian tube 216 downward (in the orientation illustrated) against the underlying pelvic organs 254, thus potentially enabling cutting wire 222 to undesirably cut this body tissue as well. Thus, it can be advantageous to approach fallopian tube 216 from different directions, such as above and / or below, depending on the presence and location of surrounding anatomy. With the present disclosure, cutting wire 222 can have a cross-sectional profile with a plurality of tips projecting in different orientations to preserve and allow the ability of a cutting wire to cut in multiple directions with a fine tip.

[0048] As previously discussed, conventional systems have injection at the distal end of the sheath on the side of the cutting wire. The cutting wire can interfere with the ejected fluid. Thus, in order to eject fluid, such as water or saline, from sheath 220, it is typically required to retract cutting wire 222 into sheath 220. With the present disclosure, cutting wire 222 can be configured to have a forward-ejecting waterjet having an internal lumen from which fluid can be ejected, thereby allowing dispensing of fluid with cutting wire 222 remaining in a desired position. Thus, the fluid can be injected into the surgical side more accurately, amongst other benefits.

[0049] Furthermore, the distance that cutting wire 222 is configured to extend from sheath 220 is typically set be a fixed distance. That is, cutting wire 222 is typically pushed forward at handle 224 to the distal -most position to be used making the use of intermediate positionsbetween fully retracted and fully extended difficult. With the present disclosure, an insulating disk can be locked into multiple positions along cutting wire 222 to prevent cutting wire 222 from cutting proximally of the insulating disk and also controlling cutting depth.

[0050] The present disclosure includes a dual function electrosurgical knife that can be used for ESD procedures. The knife, e.g., cutting wire 222 or electrode 304 of FIG. 4 - FIG. 7, can be made of surgical stainless steel in pointed design, such as a six-point star design. The length of the knife can be 3.5 mm. This design can reduce material and maintain strength, thereby allowing for more efficient cutting. This design can also have a sharp edge in multiple directions that can be ready to cut with less charring effect. Thus, movement of the knife in any direction can perform cutting. The knife can have an insulating disk, such as a porcelain slider, that has one or more actuation rods that can push and pull the insulating disk forward and backward into multiple positions, e.g., three positions. A first position can lock the depth at 2 mm cutting, for example, a second position can set the depth at 1.5mm cutting, for example. A third position can turn the knife into an insulated tip knife. The insulating disk can be locked into such positions. Electrosurgical knives of the present disclosure can have increased utility over conventional systems and can be fabricated at reasonable cost relative to the increased functionality. For example, a surgical knife of the present disclosure could be less expensive that the cost of two knives required to provide comparable functionality or utility.

[0051] FIG. 4 is a schematic diagram of electrosurgical device 300 of the present disclosure comprising sheath 302, electrode 304, insulating disk 306 and actuator 308. FIG. 5 is a perspective exploded view of electrosurgical device 300 of FIG. 4. FIG. 6 is an end view of electrosurgical device 300 of FIG. 4. FIG. 4, FIG. 5 and FIG. 6 are discussed concurrently unless otherwise noted.

[0052] The features of sheath 302, electrode 304 and insulating disk 306 can be incorporated into sheath 18 and probe 17 of FIG. 1 according to the present disclosure. The features of sheath 302, electrode 304 and insulating disk 306 can be incorporated into sheath 220 and cutting wire 222 of FIG. 3 according to the present disclosure.

[0053] Sheath 302 can comprise tubular body 310 having lumen 312. Tubular body 310 can comprise an elongate, flexible member configured for insertion into a patient, such as through endoscope 204 (FIG. 2), to deliver electrode 304 to target anatomy. In examples, tubular body 310 can comprise a polymeric, plastic or rubber tube. Lumen 312 can define a space in which components of electrosurgical device 300 that need to reach electrode 304 at the distal end of sheath 302, such as actuator 308, fluid tube 342 and control wire 340 of FIG. 7, can bepositioned for connecting electrode 304 to other proximal components of electrosurgical device 300 at handle 350 (FIG. 8), such as energy source 228 and fluid source 229 (FIG. 2).

[0054] Insulating disk 306 can comprise plate body 330 having channel 332. Plate body 330 can be made of an insulating material that prevents transfer of electrical and / or thermal energy from control wire 340 (FIG. 7). In examples, plate body 330 can be fabricated of an aluminum oxide material, a ceramic material or a porcelain material. In examples, plate body 330 can be fabricated from a polymer, low-carbon content polymer, or nylon. In examples, plate body 330 can be made of a metal to facilitate attachment to actuator 308, as discussed below, and then coated with an insulating material. Plate body 330 can have thickness T, as shown in FIG. 5. Thickness T can be in the range of approximately 0.5 mm to approximately 2.0 mm. Thickness T can be sufficient such that distal-most face 338 of insulating disk 306 can extend beyond distal-most face 334 of electrode 304 while having a proximal-most face of insulating disk 306 remain engaged with electrode 304. Thus, as discussed with reference to FIG. 12A, insulating disk 306 can provide a buffer against the tip of electrode 304 contacting tissue, thereby forming an insulated tip. Channel 332 can comprise a cut-out that is shaped to have a mating profile as the cross-sectional profile of elongate body 320. Channel 332 can extend through the thickness of plate body 330.

[0055] Actuator 308 can comprise one or more elongate bodies 309, such as wires or rods, having proximal ends connected to handle 224 (FIG. 2) or handle 350 (FIG. 9) and distal ends connected to insulating disk 306. Elongate bodies 309 can be pushed and pulled, such as at a control feature, e.g., lever 365 on handle 350 (FIG. 8), to move insulating disk 306 back-and-forth along elongate body 320. Elongate bodies 309 can comprise metal bodies attached to insulating disk 306 is any suitable manner. In examples, elongate bodies 309 of actuator 308 can be welded to insulating disk, and insulating disk can then be coated with an insulating material such as by a dipping or spray process. In examples, elongate bodies 309 can be riveted to insulating disk 306. In examples, elongate bodies 309 can be inserted through bores or channels within insulating disk 306 and then deformed to provide a mechanical connection or welded. In examples, elongate bodies 309 can be coated with an insulator to prevent electricity from being transmitted therethrough. In examples, elongate bodies 309 can be configured to receive activation energy from control wire 340 to provide additional cutting edges. As such, the size or diameter of elongate bodies 309 can be selected to enhance cutting performance.

[0056] Electrode 304 can comprise elongate body 320 and lumen 322. As discussed in detail below, electrode can be electrically coupled to handle 224 (FIG. 2) to receive electrical powerfrom cord 226 such as via energy source 228 (FIG. 2) and lumen 322 can be fluid coupled to handle 224 (FIG. 2) to receive a fluid from fluid source 229 (FIG. 2). In use, electrode 304 can be configured to be moved axially relative to sheath 302. As discussed in greater detail with reference to FIG. 8, handle 224 (FIG. 2) can include slider 354 for advancing and retracting electrode 304 and stop 356 and stop 358 for limiting movement of insulating disk 306. However, electrode 304 can be disposed within sheath 302 in a fixed position. To control the cutting depth or length of electrode 304, insulating disk 306 can be moved along electrode 304 using actuator 308.

[0057] As shown in FIG. 5, elongate body 320 can have a cross-sectional profile having multiple points 324 and troughs 326. In examples, electrode 304 can be fabricated from stainless steel and can be pressed, extruded, machined or the like. In examples, electrode 304 can be cold hammer forged. In examples, electrode 304 can be fabricated from tungsten or another thermally conductive material to allow electrode 304 to be heated with activation energy to enhance cutting procedures. In examples, electrode 304 can be stiff so as to not bend.

[0058] Each of the points 324 can form a cutting edge that can allow electrode 304 to cut in multiple directions. Each of points 324 of electrode 304 can provide cutting capability in a radial direction extending along an edge that is parallel to axis AA. In the illustrated example, elongate body 320 has the cross-sectional profile of a star. Specifically, in the illustrated example, the cross-sectional profile of elongate body 320 can comprise a six- pointed star that provides cutting in six directions spaced apart sixty degrees. However, other cross-sectional profile shapes can be used that have one or more apices or apexes that can form cutting edges or narrow cutting surfaces. Thus, an apex can comprise a point, such as an edge along a star-shaped electrode or a rectilinear-shaped electrode, or can comprise a curved surface, such as on a lobed or clover-leaf-shaped electrode. In examples electrode 304 can have a cross-sectional profile that is a five-pointed star or a four-point star (FIG. 15). Additionally, triangular cross-sectional profile shapes or square cross-sectional profile shapes (FIG. 16) can be used wherein the flat surfaces of the triangle can be spaced from the interior of lumen 312 to provide space for actuator 308 and other components. Additionally, lobed cross-sectional profile shapes can be used wherein the arcuate tips of the lobes can be used as cutting surfaces and crevices between the lobes can be used as space for other components, such as actuator 308, fluid tubes and other components.

[0059] Troughs 326 can form channels or indentations within elongate body 320 for receiving elongate bodies 309 or wires that can actuate insulating disk 306. Troughs 326 cancomprise depressions within elongate body 320 radially inward of the radial outer diameter of elongate body 320. Troughs 326 provide space for the location of other features or components of electrosurgical device 300, such as actuator 308. Thus, inclusion of actuators 308 within electrosurgical device 300 does not increase the overall size, e.g., outer diameter of the device. In particular, actuator 308 can fit within the outer perimeter of electrode 304, e.g., radially inward of points 324, as shown in FIG. 14. As such, space radially outward of electrode 304, e.g., radially outward of points 324, within sheath 302 is not needed for or occupied by actuator 308. Actuator 308 can comprise elongate bodies 309 disposed within troughs 326. Elongate bodies 309 can comprise a pair of elongate bodies located at circumferentially opposite positions, e.g., one-hundred-eighty degrees apart, about the perimeter of elongate body 320. Troughs 326 can extend axially parallel to axis AA. In the illustrated example, the bottom of troughs 326 come to points such that the troughs are V- shaped. However, the bottom of troughs 326 can have other shapes, such as rounded or semicircular, to form U-shaped troughs that increase space within the troughs relative to the V- shape. Troughs 326 can facilitate cooling of electrode 304, such as by decreasing mass of electrode 304 and increasing surface area of electrode 304. Troughs 326, as well as thickness T, can additionally facilitate axial alignment of insulating disk 306 with electrode 304. For example, the plurality of points 324 and troughs 326 that engage with channel 332 on insulating disk 306 can prevent binding of insulating disk 306 along electrode 304 while being pushed or pulled along electrode 304. The distance or gap between channel 332 and elongate body 320 can be small to facilitate scraping of debris from electrode 304 by insulating disk 306 and to facilitate axial alignment between electrode 304 and insulating disk 306.

[0060] As shown in FIG. 6, the star-shape cross-sectional profile of elongate body 320 can form central portion 336 radially inward of troughs 326 that provides space to accommodate lumen 322. Lumen 322 can comprise a passage or bore through which a fluid can be passed to reach distal-most face 334. Elongate body 320 can be connected to fluid source 229 (FIG. 2) to provide irrigation capabilities. Lumen 322 can comprise a circular passage, as illustrated, but can have other cross-sectional shapes, including square, rectangular, oval, elliptical and the like. Lumen 322 can be made by any suitable process, such as casting or machining. In examples, lumen 322 can be omitted, as shown in FIG. 14. The size, e.g., diameter, of central portion 336 can be changed by changing the depth of troughs 326 within elongate body 320. As such, the depth of troughs 326, the number of points 324, the width of points 324 and the diameter of lumen 322 can be selected by balancing the capabilities ofelectrode 304, such as the number of cutting edges, the thickness of the cutting edges, the volume of trough 326 to hold other components and the volume of fluid to be delivered by lumen 322, and the like. Furthermore, as shown in FIG. 6, the height H of insulating disk 306 beyond points 324 can be small so that the outer diameter of electrosurgical device 300 is not greatly increased beyond the diameter of electrode 304. Additionally, insulating disk 306 can remain within the outer diameter OD of sheath 302 regardless of axial position along electrode 304, e.g., whether or not within, adjacent to or distal of sheath 302. As such, the use of insulting disk 306 to form an insulated-tip electrode does not affect the overall size of the cutting that can be performed by electrode 304.

[0061] FIG. 7 is a schematic cross-sectional view of a distal end portion of electrosurgical device 300 of the present disclosure showing control wire 340, fluid tube 342 and elongate bodies 309 of actuator 308. Electrode 304 can be disposed within lumen 312 of tubular body 310. Insulating disk 306 can be disposed around electrode 304 distal of tubular body 310. Elongate bodies 309 of actuator 308 can extend from a proximal side of insulating disk 306 through lumen 312 to reach handle 350 (FIG. 8).

[0062] In examples, electrode 304 can extend all the way back to handle 224 in a contiguous fashion such that the cross-sectional shape illustrated in FIG. 4, for example, extends all the way to handle 224. In the illustrated example, electrode 304 can extend partially into sheath 302 and another conductor such as one or more wires or cables, e.g., control wire 340 (FIG. 7 - FIG. 9) can connect electrode 304 to handle 224 or handle 350. Control wire 340 can have a smaller diameter than electrode 304 to facilitate flexing of sheath 302.

[0063] Elongate bodies 309 of actuator 308 can connect to a proximal face of insulating disk 306 and can extend proximally alongside electrode 304 to a control feature, e.g., lever 365 (FIG. 9). Actuator 308 can comprise one or more rods or wires that can be pulled and pushed to translate insulating disk 306 along electrode 304 to adjust the cutting length of electrode 304 and scrape tissue or debris from electrode 304.

[0064] Control wire 340 can comprise a conductive body such as a wire or cable that can convey activation energy, e.g., electricity, thermal energy and / or RF energy from energy source 228 (FIG. 2) to electrode 304. In examples, control wire 340 can be made of a conductive metal, such as copper, aluminum or steel, and can be flexible.

[0065] Fluid tube 342 can be connected to electrode 304 at lumen 322. Fluid tube 342 can have a proximal end connected to fluid source 229 (FIG. 2) to deliver fluid to electrode 304. Fluid tube 342 can be fabricated from a flexible hose or tube, such as a plastic or polymer tube.

[0066] FIG. 8 is a plan view of electrosurgical device 300 of FIG. 4 through FIG. 7 showing handle 350. Electrosurgical device 300 can comprise sheath 302 and electrode 304. Handle 350 can comprise handle body 352, slider 354, stop 356, stop 358, electrical connector 360 and fluid port 362. In examples, handle 350 can comprise handle 224 of FIG. 2.

[0067] Handle 350 can be connected to sheath 302 and electrode 304 can extend from the distal end of sheath 302. Handle 350 can include fluid port 362 that can be fluidly connected to fluid tube 342 (FIG. 7) and fluid source 229 (FIG. 2). Handle 350 can include a button or actuator (e.g., input button 21 of FIG. 1) that can control the flow of activation energy to electrode 304, such as via electrical connector 360 and control wire 340, from energy source 228. Additionally, energy source 228 can include a button or actuator for controlling flow of activation energy to control wire 340 and electrode 304. Handle 350 can include lever 365 connected to actuator 308 to adjust the position of insulating disk 306 to locate insulating disk 306 at the different positions of FIG. 12A, FIG. 12B and FIG. 12C, for example. Handle 350 can include adjustment devices, such as stop 356 and stop 358, that can inhibit movement of rods or wires of actuator 308.

[0068] As discussed, electrode 304 can be configured to protrude from the distal end of tubular body 310. Sheath 302 can be long enough to pass completely through the channel (inner lumen) of endoscope 204 (FIG. 2) and can have additional length to facilitate ease of use. The proximal end of sheath 302 can be connected to handle body 352. Slider 354 on handle body 352 can be connected to the proximal end of control wire 340. Control wire 340 can extend through the internal lumen (e.g., lumen 312 of FIG. 4) of sheath 302 and can be attached to electrode 304 at the distal end thereof. An operator can move slider 354 of handle 350 back and forth to move control wire 340 back and forth. Slider 354 can be advanced forward (e.g., distally) to move electrode 304 to an advanced position where electrode 304 protrudes from the internal lumen of sheath 302, and slider 354 can be retracted backward (e.g., proximally) to retract electrode 304 into sheath 302. In examples, electrode 304 can be disposed within sheath 302 in a fixed position, such as with electrode 304 protruding from lumen 312 (FIG. 4), thereby allowing insulating disk 306 to control the effective cutting length of electrode 304.

[0069] Furthermore, the proximal end of control wire 340 can be connected to electrical connector 360 mounted on slider 354. An electrical cord, such as cord 226 of FIG. 2, can be connected to electrical connector 360 to bring RF electrosurgical current from a standard electrosurgical generator, such as energy source 228 to the device. The RF current can thentravel through electrical connector 360 and control wire 340 to electrode 304 connected to the leading end of control wire 340.

[0070] Fluid port 362 can connect to fluid source 229 (FIG. 2) to provide fluid to handle 350. Fluid port 362 can connect to fluid tube 342 (FIG. 7) connected to lumen 322 of electrode 304. Fluid port 362 can be coupled to handle body 352 at slide 364 to allow fluid port 362 to move as electrode 304 is moved.

[0071] FIG. 9 is a close-up view of handle 350 of FIG. 8. Control wire 340 is shown as a dashed or dotted line in FIG. 9. Actuator 308 is shown as a solid line in FIG. 9. FIG. 9 illustrates control wire 340 extending from slider 354 within handle body 352. From handle body 352, control wire 340 can extend through stop 358 and stop 356, to reach tubular body 310. However, control wire 340 is shown covered by actuator 308 within a portion of handle body 352 for illustrative purposes. Actuator 308 can extend within handle body 352 from stop 358 into stopper 366, through stop 356, alongside indicia 368 and then into tubular body 310. Actuator 308 is not shown within tubular body 310 for simplicity.

[0072] Indicia 368 can comprise a scale or other information to provide an indication of the position of insulating disk 306 relative to distal-most face 334 of electrode 304 to provide an indication of how much of electrode 304 is available to cut. For example, indicia 368 can provide text, such as “1.5 mm,” “2.0 mm” and the like, to indicate the length of electrode 304 between distal-most face 334 of electrode 304 and distal-most face 338 of insulating disk 306. Lever 365 can be used to advance actuator 308 to move insulating disk 306 to the positions indicated by indicia 368. Lever 365 can be directly connected to actuator 308 or can be connected to stopper 366. Lever 365, stopper 366 and actuator 308 can be visible and accessible through handle body 352 via a window or cut-out, as shown in FIG. 9. As discussed below, actuator 308 can be locked in place using one or more stops, such as stop 356 and stop 358, to immobilize insulating disk 306, e.g., fix the position of insulating disk 306.

[0073] FIG. 10 is a perspective view of stopper 366 connected to actuator 308 for insulating disk 306 of the present disclosure. FIG. 11 A is a schematic cross-sectional view of stopper 366 of FIG. 10 within stop 356 such that stopper 366 cannot pass through stop 356. FIG.1 IB is a schematic cross-sectional view of stopper 366 of FIG. 10 within stop 356 such that stopper 366 can pass through stop 356.

[0074] Stopper 366 can be connected to actuator 308 to control axial movement of control wire 340 and insulating disk 306. Stop 358 is illustrated proximally of stopper 366 and stop 356 is located distally of stopper 366. However, stopper 366 can be configured to movethrough each of stop 356 and stop 358 depending on the rotational orientation of stop 356 and stop 358. Stop 356 and stop 358 can comprise knobs that can be rotated to lock and unlock actuator 308. In examples, stop 356 and stop 358 can be located in fixed positions along handle body 352. However, in the example of FIG. 8 and FIG. 9, stop 356 and stop 358 can be threadedly engaged with handle body 352 and the positions of stop 356 and stop 358 can be adjusted by a user by threading stop 356 axially forward or axially backward on mating threading of handle body 352.

[0075] As shown in FIG. 11 A and FIG. 1 IB, stop 356 can include cutout 370 that can accept projection 372 of stopper 366. Body 375 of stopper 366 can be positioned axially inline with actuator 308 to move through the interior of stop 356. However, projection 372 can be long enough to extend out of the interior of stop 356 to engage stop 356. When stop 356 is rotated to the left in the “limited” position, as shown in FIG. 11 A, cutout 370 is offset from projection 372, thereby preventing projection 372 from passing therethrough. However, when stop 356 is rotated to the right in the “free” position, as shown in FIG. 1 IB, cutout 370 is aligned with projection 372 thereby allowing projection 372 to pass through stop 356.

[0076] Stop 358 can be configured similarly to stop 356 such that stop 356 and stop 358 can comprise consecutive or sequential stops for actuator 308. Stop 358 can allow electrode 304 to extend beyond sheath 302 a first amount and stop 356 can allow electrode 304 to extend beyond sheath 302 a second amount greater than the first amount. In an example, stop 356 can position insulating disk 306 approximately 1.5 mm from distal-most face 334 and stop 358 can position insulating disk 306 approximately 2.0 mm from distal-most face 334. An indicator features, such as an arrow, can be located on actuator 308 to point to text or numbers on indicia 368 to provide an indication of the current cutting length of electrode 304.

[0077] FIG. 12A shows insulating disk 306 in an extended state along electrode 304. In a distal-most state, insulating disk 306 can be proximate to distal-most face 334 of electrode 304. In examples, distal-most face 338 of insulating disk 306 can be located distal of distal- most face 334 of electrode 304 to ensure that electrode 304 is spaced from tissue engaged by insulating disk 306. In examples, insulating disk 306 can have a thickness of approximately 0.5 mm to approximately 2.0 mm, plus or minus ten percent. In examples, insulating disk 306 can be thicker than 2.0 mm. In the position of FIG. 12A, electrode 304 can be configured as an insulated tip electrode.

[0078] FIG. 12B shows insulating disk 306 in an intermediate state along electrode 304. In an intermediate state, insulating disk 306 can be located between distal-most face 334 of electrode 304 and sheath 302. Insulating disk 306 can be located in any position betweendistal-most face 334 and sheath 302. In examples, the intermediate position can be 2.0 mm or 1.5 mm, plus or minus ten percent, from distal-most face 334.

[0079] FIG. 12C shows insulating disk 306 in a retracted state along electrode 304. In a proximal-most state (FIG. 12C), insulating disk 306 can be adjacent sheath 302. In examples, insulating disk 306 can be retracted into sheath 302. In examples, electrode 304 can extend from sheath 302 approximately 3.5 mm, plus or minus ten percent.Coatings

[0080] In examples, one, a combination of some, or all of electrode 304, insulating disk 306 and actuator 308 can be provided with one or more layers that prevents sticking of tissue to such components. In examples, the layer can comprise a coating or an etched layer.

[0081] The non-stick coating can be applied to portions of the electrosurgical device to provide tissue adherence resistant (anti-stick) properties. Any material capable of providing the desired functionality (namely, reduction of tissue sticking while simultaneously maintaining sufficient electrical transmission to permit tissue sealing) may be used as the non-stick coating, provided it has adequate biocompatibility. In some examples, the material may be porous to allow for electrical transmission.

[0082] In examples, the non-stick layer can comprise a hydrophobic coating, an super / ultra- hydrophobic coating, a hydrophilic coating or a super / ultra-hydrophilic coating.

[0083] As used herein, “liquidphobic” or “super-liquidphobic” structures describe, in a general sense, any material that displays anti-liquid properties, e.g., a material that is one or more of hydrophobic (repels water), lipophobic (repels oils and lipids), amphiphobic (a material which is both hydrophobic and lipophobic), hemophobic (repels blood or blood components) or the like. Such materials repel liquids, e.g., by causing the liquid to bead-up on the material’s surface and not spread out or wet the material’s surface. Thus, as used herein, a substrate that is described as comprising a liquidphobic structure includes substrates that comprise a liquidphobic, super-liquidphobic, hydrophobic, super-hydrophobic, amphiphobic and / or super-amphiphobic substrate.

[0084] When a drop of a liquid (e.g., water based, lipid based, etc.) rests upon a surface, it will spread out over the surface to a degree based upon such factors as the surface tensions of the liquid and the substrate, the smoothness or roughness of the surface, etc. For example, the liquidphobicity of a substrate can be increased by various coatings that lower the surface energy of the substrate. The quantification of liquidphobicity can be expressed as the degree of contact surface angle (or contact angle) of the drop of the liquid on the surface.

[0085] For example, for a surface having a high surface energy (i.e., higher than the surface tension of the liquid drop), a drop of liquid will spread out “wetting” the surface of the substrate. Such surface displays liquidphilicity, as opposed to liquidphobicity. When the surface energy of a substrate is decreased, liquidphobicity is increased (and vice versa).

[0086] Liquidphobic, including hydrophobic, lipidphobic and / or amphiphobic refer to properties of a substrate which cause a liquid drop on their surface to have a contact angle of 90 degrees (°) or greater. Super-hydrophobicity, super-amphiphobicity, ultrahydrophobic and super-liquidphobicity all refer to properties of substances which cause a liquid drop on their surface to have a contact angle of 150° or greater. A hydrophilic coating is one with a water contact angle of less than 90°.

[0087] The liquidphobic structures, when applied to electrosurgical devices, can reduce the sticking of tissue during the application of electrosurgical energy for treating tissue. For example, the superhydrophobicity texture consists of an array of micro pillars that supports the water droplets (can be saline or other liquid) and not adhere to the surface. In contrast, a substrate without the micro-pillar allows the water droplets to spread across the surface.

[0088] In examples, materials such as silicone and silicone resins can be used for the nonstick coating. Silicone resins suitable for the non-stick coating include, but are not limited to, polydimethyl siloxanes, polyester-modified methylphenyl polysiloxanes, such as polymethylsilane and polymethylsiloxane, and hydroxyl functional silicone resins. In some examples, the non-stick coating is made from a composition including a siloxane, which may include hexamethyldisiloxane, tetramethylsilane, hexamethyldisilazane, or combinations thereof.

[0089] In examples, the non-stick coating is a polydimethylsiloxane (“PMDSO”) coating. In examples, the non-stick coating is a hexamethyldisiloxane (“HMDSO”) coating. In other examples, the non-stick coating is a tetramethyldisiloxane (TMDSO or TMDS), and other polysiloxanes.

[0090] HMDSO when applied to a surface can tend towards a superhydrophobic state (depending on application settings) or at least above those typically achieved by the same materials being applied in a non-hydrophobic pillar creating process or other chemical assembly of these materials that do not combine to create this polymeric structure. Hydrophobic pillars can be arranged in the ‘Cassie’s State’ or the ‘Wenzel’s state.’

[0091] The present disclosure includes a superhydrophobic or superoleophobic article. The article can includes substrate, such as on an electrode, actuator or insulating disk described herein, and a superhydrophobic or superoleophobic portion disposed on a surface of thesubstrate. The superhydrophobic or superoleophobic portion, the substrate, or both are substantially transparent, comprise a color, or both. The present disclosure further includes a superhydrophobic or superoleophobic article. The article includes a substrate and a superhydrophobic or superoleophobic portion disposed on a surface of the substrate. The superhydrophobic or superoleophobic portion is at least partially disposed on a surface of the substrate and includes tungsten disulfide, hexamethyldisiloxane, tetramethyldisiloxane, fluorosilane, a glass, a perfluoropolyether, manganese oxide polystyrene, zinc oxide polystyrene, precipitated calcium carbonate, or a mixture thereof. The superhydrophobic or superoleophobic portion further includes a structural microstructure, a structural nanostructure, or a combination thereof.

[0092] In examples, the non-stick coating has a substantially uniform thickness. In another example, the non-stick coating has a non-uniform thickness. In additional examples, the nonstick coating is discontinuous. In additional examples, the non-stick coating is continuous. In examples, the electrosurgical instrument also includes an insulative layer disposed on at least a portion of the electrode, actuator or insulating disk described herein.

[0093] In examples, a thickness of the non-stick coating can be in the range of 10 nm to about 250 nm and provide non-stick benefits. However, while non-stick properties can be provided, various portions of this range can provide additional benefits, while still providing tissue adhesion resistance and sensing capability. In examples, the non-stick coating can be a thin coating, e.g., having a thickness in the range of, but not limited to, about 10 nm to about 30 nm. In other examples, the non-stick coating has a thickness in the range of about 10 nm to about 20 nm.

[0094] The application of the non-stick coating may be accomplished using any system and process capable of precisely controlling the thickness of the coating. In some examples, HMDSO is deposited on the electrode, actuator and / or insulating disk using plasma enhanced chemical vapor deposition (PECVD) or other suitable methods such as atmospheric pressure plasma enhanced chemical vapor deposition (AP -PECVD). For example, the application of the polydimethylsiloxane coating may be accomplished using a system and process that includes a plasma device coupled to a power source, a source of liquid and / or gas ionizable media (e.g., oxygen), a pump, and a vacuum chamber. The power source may include any suitable components for delivering power or matching impedance to the plasma device.More particularly, the power source may be any radio frequency generator or other suitable power source capable of producing electrical power to ignite and sustain the ionizable media to generate a plasma effluent. In examples, the silicone and silicone resins can be appliedusing a plasma deposition process to precisely control thickness, and can withstand the heat generated during tissue sealing.

[0095] The HMDSO plasma coating may be applied using a system or process which includes a plasma device that is coupled to a power source, an ionizable media source and a precursor or pre-ionization source. The power source may include any suitable components for delivering power or matching impedance to the plasma device. More particularly, the power source may be any radio frequency generator or other suitable power source capable of producing electrical power to ignite and sustain the ionizable media to generate a plasma effluent.

[0096] Plasmas are generated using electrical energy that is delivered as either direct current (DC) electricity or alternating current (AC) electricity, in either continuous or pulsed modes, at frequencies from about 0.1 hertz (Hz) to about 100 gigahertz (GHz), including radio frequency bands (“RF”, from about 0.1 MHz to about 100 MHz) and microwave bands (“MW”, from about 0.1 GHz to about 100 GHz), using appropriate generators, electrodes, and antennas. AC electrical energy may be supplied at a frequency from about 0.1 MHz to about 2,450 MHz, in embodiments from about 1 MHz to about 160 MHz. The plasma may also be ignited by using continuous or pulsed direct current (DC) electrical energy or continuous or pulsed RF electrical energy or combinations thereof. Choice of excitation frequency, the workpiece, as well as the electrical circuit that is used to deliver electrical energy to the circuit affects many properties and requirements of the plasma. The performance of the plasma chemical generation, the gas or liquid feedstock delivery system and the design of the electrical excitation circuitry are interrelated, as the choices of operating voltage, frequency and current levels, as well as phase, effect the electron temperature and electron density. Further, choices of electrical excitation and plasma device hardware also determine how a given plasma system responds dynamically to the introduction of new ingredients to the host plasma gas or liquid media. The corresponding dynamic adjustment of the electrical drive, such as via dynamic match networks or adjustments to voltage, current, or excitation frequency may be used to maintain controlled power transfer from the electrical circuit to the plasma.

[0097] In one example, the non-stick coating can be formed using etching. In some examples, adhesion can be enhanced by roughing or etching the portion of the substrate that contacts the superhydrophobic or superoleophobic portion, the portion of the superhydrophobic or superoleophobic portion that contacts the substrate, or both. Roughingor etching can be accomplished using e-beam radiation, a chemical etchant (e.g., an acid), or a combination thereof.Method

[0098] FIG. 13 is a block diagram illustrating operations of methods 400 for performing an electrosurgical procedure with electrosurgical device 300 of the present disclosure, for example. Method 400 can include operation 402 through operation 422. In examples, some of operation 402 through operation 422 can be omitted and in examples operation 402 through operation 422 can be performed in other sequences.

[0099] At operation 402, electrosurgical device 300 can be inserted into anatomy. Electrosurgical device 300 can be sterilized in preparation for insertion. Energy source 228 and fluid source 229 can be connected to electrosurgical device 300. Electrosurgical device 300 can be inserted into a body of a patient through an appropriate entry point, such as an incision or natural orifice, using an endoscope if necessary, to reach target anatomy, such as target anatomy206 of FIG. 2. Electrosurgical device 300 can be navigated to target tissue area, using a guidance system of an endoscope for precise placement if desired.

[0100] At operation 404, the position of insulating disk 306 can be set along electrode 304. Stop 356 and stop 358 can be adjusted to move insulating disk 306 to the desired position. Lever 365 (FIG. 9) can be advanced or retracted to move insulating disk 306. Indicia 368 can be referenced to determine where to position insulating disk 306. In an example, insulating disk 306 can be positioned approximately 2.0 mm from the distal-most face of electrode 304. The adjustment of the position of insulating disk can control the cutting depth, allowing for precise surgical incisions tailored to the specific procedure.

[0101] At operation 406, electrode 304 can be energized using one or more activation energies, such as electricity, heat and RF energy, to perform a first cut of the target tissue. Activation energy can travel from energy source 228, through cord 226, into electrical connector 360, along control wire 340 and into electrode 304. A button, such as input button 21 (FIG. 1) on handle 350 (FIG. 9) can be pushed to activate the energy.

[0102] At operation 408, fluid can be injected from lumen 322 of electrode 304 onto the target tissue. The fluid can flow from fluid source 229, through cord 226, through fluid port 362, through fluid tube 342 and through lumen 322 of electrode 304 to reach the target tissue. The fluid can be ejected from distal-most face to avoid having to reposition electrode 304. This can be done without retracting the electrode, maintaining its strategic position relative to the tissue. A button on handle 350 (FIG. 9) can be pushed to activate the flow of fluid toelectrode 304. If another cut is desired, method 400 can proceed to operation 410. If a cut that benefits from the use of an insulated tip is desired, method 400 can proceed to operation 416. If the procedure is completed, method 400 can advance to operation 422.

[0103] At operation 410, the position of insulating disk 306 on electrode 304 can be adjusted. In examples, the position of insulating disk 306 can be adjusted to scrape tissue off of electrode. In examples, the position of insulating disk 306 can be adjusted to perform a second cut of the target tissue at a different depth or length.

[0104] At operation 412, electrode 304 can be energized using one or more activation energies, such as electricity, heat and RF energy, to perform a second cut of the target tissue in the same manner as operation 406.

[0105] At operation 414, fluid can be injected from lumen 322 of electrode 304 onto the target tissue in the same manner as operation 408. If a cut that benefits from the use of an insulated tip is desired, method 400 can proceed to operation 416. If the procedure is completed, method 400 can advance to operation 422.

[0106] At operation 416, the position of insulating disk 306 on electrode 304 can be adjusted. In examples, the position of insulating disk 306 can be adjusted to scrape tissue off of electrode. In examples, the position of insulating disk 306 can be adjusted to perform a third cut of the target tissue at a different depth or length. If desired or required, insulating disk 306 can be slid to the distal-most position to create an insulated tip. This prevents the electrode tip from contacting and potentially damaging surrounding tissue during the procedure.

[0107] At operation 418, electrode 304 can be energized using one or more activation energies, such as electricity, heat and RF energy, to perform a third cut of the target tissue in the same manner as operation 406.

[0108] At operation 420, fluid can be injected from lumen 322 of electrode 304 onto the target tissue in the same manner as operation 408.

[0109] At operation 422, electro surgical device 300 can be withdrawn from the anatomy of the patient and the procedure or surgical task can be completed, such as by withdrawing an endoscope if used and closing any access incisions made in the patient if appropriate. The electrode can be retracted into the sheath and electrosurgical device 300 can be removed from the patient's body through the endoscope, if used.

[0110] This method leverages the unique features of the adjustable electrosurgical knife to provide a versatile and efficient tool for a variety of surgical applications, enhancing patient safety and surgical outcomes.Additional Electrode Configurations[OHl] FIG. 14 is an end view electrode 304 of the present disclosure wherein lumen 322 (FIG. 4) has been omitted. Electrode 304 can comprise body 320, points 324, troughs 326 and distal-most face 334. Electrode 304 can be configured as described herein with reference to FIG. 4 through FIG. 7, with a difference being that lumen 322 is omitted. Electrode 304 can be circumscribed by circle 380. Circle 380 thus comprises a hypothetical or virtual, geometric illustration that approximates the smallest circle in which electrode 304 will fit. Electrode 304 can be surrounded by insulating disk 306, which can fit within sheath 302. Electrode 304 can be more easily manufactured with lumen 322 omitted. Furthermore, troughs 326 can provide space within sheath 302 (FIG. 4) for the inclusion of tubes or hoses from providing fluid to the distal end of electrode 304. Actuators 308 can fit within the space produced by troughs 326, thereby allowing actuators 308 to fit between circle 380 and electrode 304, e.g., within the outer perimeter of electrode 304. As such, actuators 308 do not increase the size of electrosurgical device 300 by having to provide space between the outer perimeter of electrode 304, e.g., circle 380, and the inner diameter of sheath 302 for actuators 308.

[0112] As mentioned, the electrodes of the present disclosure can include one or more apices or apexes that can be used to perform cutting or other functions. The apices can form surfaces that have small total areas to concentrate electrical energy and other energy types. The apices can also form gaps or spaces around which an insulating disk can fit and in which an actuator can fit to move the insulating disk. FIG. 15, FIG. 16 and FIG. 17 show additional configurations of electrodes of the present disclosure that can be used as electrode 304 of FIG. 4 through FIG. 7.

[0113] FIG. 15 is an end view of electrosurgical device 500 comprising electrode 504 and actuators 508. Electrode 504 can comprise body 520, points 524, troughs 526 and distal-most face 534. Electrode 504 can be circumscribed by circle 580. Circle 580 thus comprises a hypothetical or virtual, geometric illustration that approximates the smallest circle in which electrode 504 will fit. Electrode 504 can be surrounded by an insulating disk (not shown) having an inner slot or bore that mates with electrode 504, as described herein. The insulating disk can fit within sheath 302 (FIG. 4). Additionally, electrode 540 can include an internal lumen (not shown) for receiving a fluid. Actuators 508 can be connected to an insulating disk (not shown) configured to fit within sheath 302 (FIG. 4) and having a through- bore with the inverse cross-sectional shape of electrode 504, similar to insulating disk 306described herein. Electrode 504 can be configured to operate similarly to electrode 304 described herein, but can have a different cross-sectional profile. In the illustrated example, electrode 504 comprises a four-pointed star that results in four of points 524 and four of troughs 526. Points 524 can comprise cutting edges. As discussed herein, space produced within sheath 302 by troughs 526 can allow for the inclusion of other components, such as actuators 508 or fluid tubes. Actuators 508 can fit within the space produced by troughs 526, thereby allowing actuators 508 to fit between circle 580 and electrode 504, e.g., within the outer perimeter of electrode 504. As such, actuators 508 do not increase the size of electrosurgical device 500 by having to provide space between the outer perimeter of electrode 504, e.g., circle 580, and the inner diameter of sheath 302 (FIG. 4) for actuators 508. Troughs 526 can have depth DI. The length of depth DI can be varied in different embodiments of electrode 504. Increased length of DI can result in larger troughs 526 to produce more storage space, a smaller internal area for the inclusion of a fluid lumen, and sharper points 524. Decreased length of DI can result in smaller troughs 526 to produce less storage space, a larger internal area for the inclusion of a fluid lumen, and duller points 524.

[0114] FIG. 16 is an end view of electrosurgical device 600 comprising electrode 604 and actuators 608. Electrode 604 can comprise body 620, points 624, facets 626 and distal-most face 634. Electrode 604 can be circumscribed by circle 680. Circle 680 thus comprises a hypothetical or virtual, geometric illustration that approximates the smallest circle in which electrode 604 will fit. Electrode 604 can be surrounded by an insulating disk (not shown) having an inner slot or bore that mates with electrode 604, as described herein. The insulating disk can fit within sheath 302 (FIG. 4). Additionally, electrode 640 can include an internal lumen (not shown) for receiving a fluid. Actuators 608 can be connected to an insulating disk (not shown) configured to fit within sheath 602 and having a through-bore with the inverse cross-sectional shape of electrode 604, similar to insulating disk 306 described herein. Electrode 604 can be configured to operate similarly to electrode 604 described herein, but can have a different cross-sectional profile. In the illustrated example, electrode 604 comprises a four-pointed square that results in four of points 624 and four of facets 626. Points 624 can comprise cutting edges. Similar to the troughs discussed herein, facets 626 can produce space within sheath 602. The space provided by facets 626 can allow for the inclusion of other components, such as actuators 608 or fluid tubes. Actuators 608 can fit within the space produced by facets 626, thereby allowing actuators 608 to fit between circle 680 and electrode 604, e.g., within the outer perimeter of electrode 604. As such, actuators 608 do not increase the size of electrosurgical device 600 by having to providespace between the outer perimeter of electrode 604, e.g., circle 580, and the inner diameter of sheath 302 (FIG. 4) for actuators 608. Facets 626 can be spaced from circle 380 a distance D2. The length of distance D2 can be determined by the size of electrode 604 relative to sheath 302 and insulating disk surrounding electrode 604. The illustrated example shows facets 626 as being flat or planar. However, in other examples, facets 626 can be curved inwardly, e.g., as concave faces. However, facets 626 can be curved outwardly, e.g., as convex surfaces, as discussed in greater detail with reference to FIG. 17.

[0115] FIG. 17 is a perspective view of electrosurgical device 700 comprising electrode 702 and insulating disk 704. Electrode 702 can comprise a multi-lobed body having lobes 706 and troughs 708. In the illustrated example, electrode 702 can comprise six lobes 706 and six troughs 708. Electrode 702 can include distal-most face 710. Tube 712 can extend through electrode702 from a proximal end to distal-most face 710. Tube 712 can include lumen 714. Insulating disk 704 can comprise outer surface 716, cut-out 718 and distal-most face 720. Insulating disk 704 can be connected to actuators 722. Lobes 607 can form elongate surfaces having a small radius of curvature that can perform cutting or other functions by concentrating electrical energy and the like. Troughs 708 can comprise spaces to receive other components, such as actuators 722 or fluid tubes. Furthermore, electrode 702 can be fabricated from a plurality of cylindrical bodies that can be attached, e.g., welded or soldered together, to form a ring-like body where lobes 706 and troughs 708 for the outer perimeter and passage 724 can be formed in the interior. Passage 724 can receive tube 712 to dispense fluid distal of distal-most face 710. In examples, tube 712 can comprise a metal body to which the plurality of cylindrical bodies can be attached, such as via resistance welding or another method. Insulating disk 704 can have cut-out 718 with an inverse shape of electrode 702 to allow insulating disk 704 to slide along electrode 702, as shown in FIG. 18 A, FIG. 18B and FIG. 18C. The shape of electrode 702 and cut-out 718 can help resist twisting of insulating disk 704.Benefits

[0116] Electrosurgical device 300 of the present disclosure can provide benefits including:

[0117] Central Fluid Injection: The knife features a central fluid injection passage that allows for fluid to be injected without the need to retract the electrode, thus maintaining the position of the electrode relative to the anatomy during a procedure.

[0118] Small Size: The multi-tipped electrodes can provide space within the device for the inclusion of actuators for insulating disks without increasing the size of the electrosurgicaldevice. The insulating disks can additionally keep the overall outer diameter of the electrosurgical knives small. For example, the insulating disks for the present disclosure do not increase the outer diameter of the device or electrode whether they are in a deployed, e.g., advanced, state or a reserved, e.g., retracted, state.

[0119] Adjustable Cutting Length: The inclusion of a moveable insulating disk that slides along the electrode enables the surgeon to adjust the effective cutting length of the electrode, allowing for control over the cutting depth without the need for multiple knives.

[0120] Insulated Tip Functionality: The moveable insulating disk can also be positioned to create an insulated tip on the electrode, preventing the tip from contacting tissue and facilitating cutting along the length of the electrode without changing instruments.

[0121] Multi-Directional Cutting: The star-shaped or multi-pointed electrode design provides cutting edges in multiple directions, enhancing the knife's versatility and efficiency in cutting tissue.

[0122] Tissue Scraping: The moveable insulating disk can be advanced and retracted in a back-and-forth manner to scrape tissue from the electrode. For example, charred tissue can be removed form the electrode by movement of the insulating disk.

[0123] Non-Stick Coatings: Various coatings can be applied to the electrode or other components to prevent or inhibit tissue from adhering to it, which can improve the performance of the knife and reduce the risk of tissue damage.

[0124] Enhanced Surgical Applications: The knife can be used in a wide range of surgical settings and procedures, including gastroenterology, general surgery, obstetrics and gynecology, ENT, pulmonary medicine, dermatology, and more.

[0125] Improved Safety and Convenience: The design of the knife addresses common problems with conventional electrosurgical knives, such as inconvenient fluid injection and the need for multiple knives, thus potentially improving the speed, safety and convenience of surgical procedures.Examples

[0126] Example 1 is an electrosurgical device comprising: a sheath; an electrode extending from the sheath, the electrode comprising: a cross-sectional profile having a multi-apical cross-sectional shape; an insulator disk positioned over the electrode distally of the sheath; and an actuator connected to the insulator disk to move the insulator disk along the electrode.

[0127] In Example 2, the subject matter of Example 1 optionally includes wherein: the multi- apical cross-sectional shape fits within a hypothetical circle touching the plurality of radially outer convexities; and the actuator fits between the electrode and the hypothetical circle.

[0128] In Example 3, the subject matter of any one or more of Examples 1-2 optionally include wherein the multi -apical cross-sectional shape comprises a square shape.

[0129] In Example 4, the subject matter of any one or more of Examples 1-3 optionally include wherein the multi -apical cross-sectional shape comprises: a plurality of radially outer convexities; and a plurality of radially inner concavities between radially outer convexities of the plurality of radially outer convexities.

[0130] In Example 5, the subject matter of Example 4 optionally includes wherein the multi- apical cross-sectional shape comprises a star shape.

[0131] In Example 6, the subject matter of any one or more of Examples 4-5 optionally include wherein the multi-apical cross-sectional shape comprises a lobed shape.

[0132] In Example 7, the subject matter of any one or more of Examples 4-6 optionally include wherein the actuator extends within a trough of the plurality of radially inner concavities.

[0133] In Example 8, the subject matter of Example 7 optionally includes wherein the actuator comprises a pair of elongate bodies extending in a pair of troughs located on opposite sides of the electrode.

[0134] In Example 9, the subject matter of Example 8 optionally includes wherein the pair of elongate bodies comprise wires or rods.

[0135] In Example 10, the subject matter of any one or more of Examples 1-9 optionally include wherein the insulator disk comprises a cut-out having an inverse shape of the multi- apical cross-sectional shape, wherein the electrode extends into the cut-out.

[0136] In Example 11, the subject matter of any one or more of Examples 1-10 optionally include a distal face of the electrode extends beyond the sheath approximately 3.5 mm.

[0137] In Example 12, the subject matter of any one or more of Examples 1-11 optionally include wherein the insulator disk fits within the sheath.

[0138] In Example 13, the subject matter of any one or more of Examples 1-12 optionally include wherein the electrode comprises a fluid passage extending through an interior of the electrode.

[0139] In Example 14, the subject matter of Example 13 optionally includes wherein the insulator disk has a distal-most surface that is configured to be positioned beyond a distal-most face of the electrode while the electrode remains connected to the electrode in a distal- most position of the insulator disk such that the insulator disk forms an insulated tip.

[0140] In Example 15, the subject matter of Example 14 optionally includes wherein the insulator disk is configured to be positioned adjacent a distal end of the sheath in a proximal- most position.

[0141] In Example 16, the subject matter of Example 15 optionally includes the insulator disk being configured to be positioned approximately 1.5 mm proximal of the distal -most surface of the electrode in a first intermediate position.

[0142] In Example 17, the subject matter of Example 16 optionally includes the insulator disk being configured to be positioned approximately 2.0 mm proximal of the distal-most surface of the electrode in a second intermediate position.

[0143] In Example 18, the subject matter of Example 17 optionally includes a controller having a device to move and lock the insulator disk at the distal-most position, the proximal- most position, the first intermediate position and the second intermediate position.

[0144] In Example 19, the subject matter of any one or more of Examples 15-18 optionally include a handle comprising: a fluid port for connecting a fluid line to the fluid passage of the electrode; a flexible electrode wire extending from the electrode to the handle to connect the electrode to an activation energy source; a control feature attached to the actuator to push and pull the insulator disk; and a locking mechanism to immobilize the actuator in one or more fixed positions.

[0145] In Example 20, the subject matter of any one or more of Examples 1-19 optionally include an outer diameter of the electrode is in a range of approximately 4.0 mm to approximately 5.5 mm.

[0146] In Example 21, the subject matter of any one or more of Examples 1-20 optionally include wherein: the electrode is fabricated from stainless steel; and the insulator disk is fabricated from porcelain.

[0147] In Example 22, the subject matter of any one or more of Examples 1-21 optionally include wherein at least one of the electrode, the insulator disk and the actuator includes a non-stick surface.

[0148] In Example 23, the subject matter of Example 22 optionally includes wherein the nonstick surface comprises a hydrophilic coating or a hydrophobic coating.

[0149] In Example 24, the subject matter of any one or more of Examples 1-23 optionally include an activation energy generator electrically coupled to the electrode.

[0150] In Example 25, the subject matter of Example 24 optionally includes wherein the actuator is in electric communication with the electrode.

[0151] Example 26 is a method for performing a surgical procedure on tissue, the method comprising: inserting an insertion sheath into anatomy to position an electrode proximate to target tissue; adjusting an insulator disk connected to the electrode to adjust a distance between a distal-most face of the electrode and the insulator disk; and energizing the electrode to cut the target tissue.

[0152] In Example 27, the subject matter of Example 26 optionally includes injecting fluid onto the target tissue through a fluid passage extending through the electrode.

[0153] In Example 28, the subject matter of Example 27 optionally includes ejecting the fluid from a distal-most face of the electrode.

[0154] In Example 29, the subject matter of any one or more of Examples 26-28 optionally include cutting the target tissue with an edge of the electrode, wherein the electrode has a cross-sectional profile with a multi-pronged shape including a plurality of points and a plurality of troughs.

[0155] In Example 30, the subject matter of Example 29 optionally includes cutting the target tissue with multiple edges of the electrode in different radial directions.

[0156] In Example 31, the subject matter of any one or more of Examples 26-30 optionally include pulling or pushing a rod or wire to adjust a position of the insulator disk.

[0157] In Example 32, the subject matter of Example 31 optionally includes actuating a lever disposed on a handle connected to the insertion sheath to pull or push the rod or wire.

[0158] In Example 33, the subject matter of any one or more of Examples 31-32 optionally include locking a position of the insulator disk.

[0159] In Example 34, the subject matter of Example 33 optionally includes wherein locking the position of the insulator disk comprises rotating a stop knob to prevent axial displacement of the rod or wire.

[0160] In Example 35, the subject matter of any one or more of Examples 26-34 optionally include scraping tissue off of the electrode by moving the insulator disk along the electrode.

[0161] In Example 36, the subject matter of any one or more of Examples 26-35 optionally include preventing tissue from attaching to the electrode using a non-stick surface of the electrode.

[0162] Each of these non-limiting examples can stand on its own, or can be combined in various permutations or combinations with one or more of the other examples.Notes

[0163] The above detailed description includes references to the accompanying drawings, which form a part of the detailed description. The drawings show, by way of illustration, specific embodiments in which the invention can be practiced. These embodiments are also referred to herein as “examples.” Such examples can include elements in addition to those shown or described. However, the present inventor also contemplates examples in which only those elements shown or described are provided. Moreover, the present inventor also contemplates examples using any combination or permutation of those elements shown or described (or one or more aspects thereof), either with respect to a particular example (or one or more aspects thereof), or with respect to other examples (or one or more aspects thereof) shown or described herein.

[0164] In this document, the terms “a” or “an” are used, as is common in patent documents, to include one or more than one, independent of any other instances or usages of “at least one” or “one or more.” In this document, the term “or” is used to refer to a nonexclusive or, such that “A or B” includes “A but not B,” “B but not A,” and “A and B,” unless otherwise indicated. In this document, the terms “including” and “in which” are used as the plain- English equivalents of the respective terms “comprising” and “wherein.” Also, in the following claims, the terms “including” and “comprising” are open-ended, that is, a system, device, article, composition, formulation, or process that includes elements in addition to those listed after such a term in a claim are still deemed to fall within the scope of that claim. Moreover, in the following claims, the terms “first,” “second,” and “third,” etc. are used merely as labels, and are not intended to impose numerical requirements on their objects.

[0165] Method examples described herein can be machine or computer-implemented at least in part. Some examples can include a computer-readable medium or machine-readable medium encoded with instructions operable to configure an electronic device to perform methods as described in the above examples. An implementation of such methods can include code, such as microcode, assembly language code, a higher-level language code, or the like. Such code can include computer readable instructions for performing various methods. The code may form portions of computer program products. Further, in an example, the code can be tangibly stored on one or more volatile, non-transitory, or nonvolatile tangible computer-readable media, such as during execution or at other times. Examples of these tangible computer-readable media can include, but are not limited to, hard disks, removable magnetic disks, removable optical disks (e.g., compact disks and digitalvideo disks), magnetic cassettes, memory cards or sticks, random access memories (RAMs), read only memories (ROMs), and the like.

[0166] The above description is intended to be illustrative, and not restrictive. For example, the above-described examples (or one or more aspects thereof) may be used in combination with each other. Other embodiments can be used, such as by one of ordinary skill in the art upon reviewing the above description. The Abstract is provided to allow the reader to quickly ascertain the nature of the technical disclosure. It is submitted with the understanding that it will not be used to interpret or limit the scope or meaning of the claims. Also, in the above Detailed Description, various features may be grouped together to streamline the disclosure. This should not be interpreted as intending that an unclaimed disclosed feature is essential to any claim. Rather, inventive subject matter may lie in less than all features of a particular disclosed embodiment. Thus, the following claims are hereby incorporated into the Detailed Description as examples or embodiments, with each claim standing on its own as a separate embodiment, and it is contemplated that such embodiments can be combined with each other in various combinations or permutations. The scope of the invention should be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

CLAIMS:

1. An electrosurgical device comprising: a sheath; an electrode extending from the sheath, the electrode comprising: a cross-sectional profile having a multi-apical cross-sectional shape; an insulator disk positioned over the electrode distally of the sheath; and an actuator connected to the insulator disk to move the insulator disk along the electrode.

2. The electrosurgical device of claim 1, wherein: the multi-apical cross-sectional shape fits within a hypothetical circle touching apices of the multi-apical cross-sectional shape; and the actuator fits between the electrode and the hypothetical circle.

3. The electrosurgical device of claim 1, wherein the multi-apical cross-sectional shape comprises a square shape.

4. The electrosurgical device of claim 1, wherein the multi-apical cross-sectional shape comprises: a plurality of radially outer convexities; and a plurality of radially inner concavities between radially outer convexities of the plurality of radially outer convexities.

5. The electrosurgical device of claim 4, wherein the multi-apical cross-sectional shape comprises a star shape.

6. The electrosurgical device of claim 4, wherein the multi-apical cross-sectional shape comprises a lobed shape.

7. The electrosurgical device of claim 4, wherein the actuator extends within a trough of the plurality of radially inner concavities.

8. The electrosurgical device of claim 7, wherein the actuator comprises a pair of elongate bodies extending in a pair of troughs located on opposite sides of the electrode.

9. The electrosurgical device of claim 8, wherein the pair of elongate bodies comprise wires or rods.

10. The electrosurgical device of claim 1, wherein the insulator disk comprises a cut-out having an inverse shape of the multi-apical cross-sectional shape, wherein the electrode extends into the cut-out.

11. The electrosurgical device of claim 1, wherein a distal face of the electrode extends beyond the sheath approximately 3.5 mm.

12. The electrosurgical device of claim 1, wherein the insulator disk fits within the sheath.

13. The electrosurgical device of claim 1, wherein the electrode comprises a fluid passage extending through an interior of the electrode.

14. The electrosurgical device of claim 13, wherein the insulator disk has a distal-most surface that is configured to be positioned beyond a distal-most face of the electrode while the electrode remains connected to the electrode in a distal-most position of the insulator disk such that the insulator disk forms an insulated tip.

15. The electrosurgical device of claim 14, wherein the insulator disk is configured to be positioned adjacent a distal end of the sheath in a proximal-most position.

16. The electrosurgical device of claim 15, wherein the insulator disk is configured to be positioned approximately 1.5 mm proximal of the distal-most surface of the electrode in a first intermediate position.

17. The electrosurgical device of claim 16, wherein the insulator disk is configured to be positioned approximately 2.0 mm proximal of the distal-most surface of the electrode in a second intermediate position.

18. The electrosurgical device of claim 17, further comprising a controller having a device to move and lock the insulator disk at the distal-most position, the proximal-most position, the first intermediate position and the second intermediate position.

19. The electrosurgical device of claim 15, further a handle comprising: a fluid port for connecting a fluid line to the fluid passage of the electrode; a flexible electrode wire extending from the electrode to the handle to connect the electrode to an activation energy source; a control feature attached to the actuator to push and pull the insulator disk; and a locking mechanism to immobilize the actuator in one or more fixed positions.

20. The electrosurgical device of claim 1, wherein an outer diameter of the electrode is in a range of approximately 4.0 mm to approximately 5.5 mm.

21. The electrosurgical device of claim 1, wherein: the electrode is fabricated from stainless steel; and the insulator disk is fabricated from porcelain.

22. The electrosurgical device of claim 1, wherein at least one of the electrode, the insulator disk and the actuator includes a non-stick surface.

23. The electrosurgical device of claim 22, wherein the non-stick surface comprises a hydrophilic coating or a hydrophobic coating.

24. The electrosurgical device of claim 1, further comprising an activation energy generator electrically coupled to the electrode.

25. The electrosurgical device of claim 24, wherein the actuator is in electric communication with the electrode.

26. A method for performing a surgical procedure on tissue, the method comprising: inserting an insertion sheath into anatomy to position an electrode proximate to target tissue;adjusting an insulator disk connected to the electrode to adjust a distance between a distal-most face of the electrode and the insulator disk; and energizing the electrode to cut the target tissue.

27. The method of claim 26, further comprising injecting fluid onto the target tissue through a fluid passage extending through the electrode.

28. The method of claim 27, further comprising ejecting the fluid from a distal-most face of the electrode.

29. The method of claim 26, further comprising cutting the target tissue with an edge of the electrode, wherein the electrode has a cross-sectional profile with a multi-pronged shape including a plurality of points and a plurality of troughs.

30. The method of claim 29, further comprising cutting the target tissue with multiple edges of the electrode in different radial directions.

31. The method of claim 26, further comprising pulling or pushing a rod or wire to adjust a position of the insulator disk.

32. The method of claim 31, further comprising actuating a lever disposed on a handle connected to the insertion sheath to pull or push the rod or wire.

33. The method of claim 31, further comprising locking a position of the insulator disk.

34. The method of claim 33, wherein locking the position of the insulator disk comprises rotating a stop knob to prevent axial displacement of the rod or wire.

35. The method of claim 26, further comprising scraping tissue off of the electrode by moving the insulator disk along the electrode.

36. The method of claim 26, further comprising preventing tissue from attaching to the electrode using a non-stick surface of the electrode.

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