Arthroscopic resection probe

Abstract

A combination arthroscopic tissue resection probe includes an elongated shaft having an outer conductive sleeve and an inner sleeve. Each sleeve includes a distal region with a cutting window, the inner sleeve being rotatable to cut tissue. An outer surface of the outer sleeve distal region carries a ceramic body (580) and an electrode (570). The active electrode (570) defines two portions angularly offset from one another, the two portions including a first portion (571) extending circumferentially and axially along the tubular distal end and a second portion (578) extending from a distal end of the first portion and across the tubular distal end, the second portion having at least one flange (595) configured to engage a notch (581) in the electrically insulating spacer (580) to resist separation of the active electrode from the electrically insulating spacer (580). The electrode, ceramic body, and outer sleeve each define a first suction (572, 586, 512) opening to draw fluid ablation byproducts through the opening into an interior of the shaft. Various methods of improving electrode attachment are disclosed that provide a low profile probe distal end while maintaining electrosurgical functionality.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Patent No. 63 / 107,766, filed on October 30, 2020, and U.S. Provisional Patent No. 63 / 223,651, filed on July 20, 2021, both of which are incorporated herein by reference in their entirety. Both of which are entitled “ARTHROSCOPIC RESECTION PROBE.” Technical Field

[0003] The present disclosure relates to surgical devices and related methods for removing tissue. More particularly, the present disclosure relates to a system for use in arthroscopic surgery that includes a powered handheld instrument coupled to a mechanical removal blade integrated with an electrosurgical assembly for ablating, cutting, or coagulating tissue. Background Art

[0004] Electrosurgical systems are used by physicians to perform specific functions during surgical procedures. For example, in ablation mode, electrosurgical systems use high-frequency electrical energy to remove soft tissue, such as nasal bone tissue, fatty tissue, or tissue within joints, such as the meniscus, or cartilage or synovial tissue. Some electrosurgical systems include suction, which can remove the resected tissue during treatment, control the rate of tissue treatment, and help cool the handheld device.

[0005] Mechanical cutting tools for tissue removal have been used for many years. These types of tools typically include a powered handpiece and a rotating cutting blade fixed to the distal end of the handpiece. In arthroscopic or endoscopic surgery, both mechanical and electrosurgical tools are often interchanged within a single cannula, suggesting a need to combine these two options in a single device. This can reduce operative time and complications associated with blood loss. However, combination devices often tend to compromise. For example, at least some of the electrosurgical components are preferably located on the outer surface of the device, with the inner portion of the device dedicated to suction and movement of the mechanical removal components. Reliably securing the electrosurgical components with minimal change in the external profile is challenging. Previous attempts at solutions have compromised by providing probes with larger profile dimensions or providing probes with reduced functionality for mechanical removal or electrosurgery. Therefore, there is a need to provide a combination device that includes a reliably secured electrosurgical component configuration while minimizing the instrument's profile dimensions without compromising both mechanical and electrosurgical functionality.

[0006] As another example, a mechanical cutting tool may include a multi-purpose handle that includes a motor. These handles and associated components may include metallic conductive components that are more easily able to conduct heat. The application of electrosurgical energy may heat the fluid drawn through the device, which may be transferred through these handle components. Previous attempts at solutions may include adding insulating or less conductive components that may be bulky, or alternatively, adding temperature sensing that may interrupt treatment. Therefore, it is desirable to provide a combined device that includes a means of limiting the temperature of the fluid drawn through the device without compromising both the mechanical cutting and electrosurgical functions.

[0007] Symbols and terminology

[0008] Certain terms are used throughout the following description and claims to refer to specific system components. Those skilled in the art will appreciate that companies that design and manufacture electrosurgical systems may refer to a component by different names. This document does not intend to distinguish between components that differ in name but not function.

[0009] In the following discussion and in the claims, the terms "including" and "comprising" are used in an open-ended fashion, and thus should be interpreted to mean "including, but not limited to..." Furthermore, the terms "couple" or "couple" are intended to represent either an indirect or direct connection. Thus, if a first device couples to a second device, that connection may be through a direct connection or through an indirect connection via other devices and connections.

[0010] Reference to a singular item includes the possibility that there are multiple identical items. More specifically, as used herein and in the appended claims, the singular forms "a," "an," "said," and "the" include the plural forms unless the context clearly dictates otherwise. It should also be noted that the claims can be written to exclude any optional elements. Thus, this statement serves as antecedent basis for the use of technical terms such as "only," "only," and the like in connection with the recitation of claim elements, or the use of a "negative" limitation. Finally, it should be understood that unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.

[0011] "Ablation" shall refer to the removal of tissue based on the interaction of the tissue with plasma.

[0012] "Ablation mode" shall refer to one or more characteristics of ablation. The absence of ablation (ie, the absence of plasma) shall not be considered an "ablation mode." A mode that performs only coagulation shall not be considered an "ablation mode."

[0013] An "active electrode" shall mean an electrode of the disclosed embodiments that produces an electrically induced tissue modifying effect when in contact with or in proximity to a target tissue for treatment.

[0014] "Return electrode" shall refer to an electrode of the disclosed embodiments that is used to provide a current path for charge relative to the active electrode and / or an electrode of the disclosed embodiments that does not itself produce an electrically induced tissue-altering effect on the target tissue being treated.

[0015] Where a range of values ​​is provided, it is understood that each intervening value between the upper and lower limits of that range and any other stated or intervening value in that stated range is encompassed within the invention. In addition, it is contemplated that any optional feature of the described inventive variations may be stated and claimed independently or in combination with any one or more features described herein.

[0016] All prior subject matter (e.g., publications, patents, patent applications, and hardware) mentioned herein are incorporated by reference in their entirety, except to the extent that the subject matter may conflict with the subject matter of the present invention (in which case the content herein prevails). The cited items are provided solely for their disclosure before the filing date of the present application. Nothing herein should be construed as an admission that the present invention is not entitled to antedate such material by virtue of prior invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] For a detailed description of exemplary embodiments, reference will now be made to the accompanying drawings, in which:

[0018] Figure 1 An exemplary system including a combined ablation probe and associated equipment connected thereto according to the present disclosure is shown;

[0019] Figure 2 shows a cutter portion of a combined ablation probe according to the present disclosure;

[0020] Figure 3A shows a perspective view of a cutter distal portion of a combination ablation probe according to the present disclosure;

[0021] Figure 3B Shown according to the present disclosure Figure 3A a bottom view of the distal portion of the tool shown in ;

[0022] Figure 3C Shown according to the present disclosure Figure 3A A side view of the distal portion of the tool shown in ;

[0023] Figure 3D Shown according to the present disclosure Figure 3A A cross-sectional view of the distal portion of the tool shown in ;

[0024] Figure 4A shows a top view of another embodiment of a cutter distal portion of a combination ablation probe according to the present disclosure;

[0025] Figure 4BShown according to the present disclosure Figure 4A A side view of the distal portion of the tool in FIG.

[0026] Figure 5A shows a perspective view of another embodiment of a cutter distal portion of a combination ablation probe according to the present disclosure;

[0027] Figure 5B Shown according to the present disclosure Figure 5A An exploded view of the distal portion of the tool is shown in FIG;

[0028] Figure 5C Shown according to the present disclosure Figure 5A Another view of the distal portion of the tool shown in ;

[0029] Figure 5D Shown according to the present disclosure Figure 5A A side view of the distal portion of the tool shown in ;

[0030] Figure 5E Shown according to the present disclosure Figure 5A an end view of the distal portion of the tool shown in;

[0031] Figure 5E Shown according to the present disclosure Figure 5A Another exploded view of the distal portion of the tool shown in ;

[0032] Figure 5G Shown according to the present disclosure Figure 5A A top view of the distal portion of the tool shown in ;

[0033] Figure 6 shows an end view of another embodiment of a cutter distal portion of a combination ablation probe according to the present disclosure;

[0034] Figure 7 shows an end view of another embodiment of a cutter distal portion of a combination ablation probe according to the present disclosure;

[0035] Figure 8A shows a perspective view of another embodiment of a cutter distal end of a combination ablation probe according to the present disclosure;

[0036] Figure 8B Shown according to the present disclosure Figure 8A A cross-sectional view of the distal portion of the tool shown in ;

[0037] Figure 9A shows a top view of another embodiment of a distal end of a cutter of a combination ablation probe according to the present disclosure;

[0038] Figure 9B Shown according to the present disclosure Figure 9AA side view of the distal portion of the tool shown in ;

[0039] Figure 10A shows a perspective view of another embodiment of a cutter distal end of a combination ablation probe according to the present disclosure;

[0040] Figure 10B Shown according to the present disclosure Figure 10A An exploded view of the distal portion of the tool is shown in FIG;

[0041] Figure 10C Shown according to the present disclosure Figure 10A A top view of the distal portion of the tool shown in ;

[0042] Figure 10D Shown according to the present disclosure Figure 10A an end view of the distal portion of the tool shown in ; and

[0043] Figure 10E Shown according to the present disclosure Figure 10A A cross-sectional view of the distal portion of the tool is shown in FIG. Summary of the Invention

[0044] Generally, the present disclosure describes a system comprising a combination device that both mechanically removes tissue and electrosurgically treats tissue. Thus, various embodiments relate to various systems and methods for removing tissue using mechanical cutting, electrosurgical ablation, and suction. The description now turns to an exemplary system.

[0045] Various embodiments relate to a combined arthroscopic probe for removing and treating tissue within a patient's body, comprising a handle portion and a cutter portion. The handle portion includes a motor that is selectively coupled to a control box for controlling the motor. The cutter portion includes an outer sleeve having a lumen extending therethrough and an inner shaft extending along the lumen. The outer sleeve can be secured to the handle portion, thereby becoming a fixed sleeve or a stationary sleeve. The outer sleeve has a window at its distal end, the window having a cutting edge. The inner shaft can also have a cutting edge at its distal end and be coupled to the motor, operable to move the inner shaft and mechanically cut tissue in cooperation with the outer sleeve window cutting edge. The inner shaft can rotate. The inner shaft can define a window that axially coincides with the outer sleeve window. The inner shaft can include an elongated hole in communication with a suction device, the elongated hole being configured to remove fluid and excision byproducts from the treatment site through the inner shaft window and along the inner shaft.

[0046] The outer sleeve comprises a conductive material, and the conductive material is at least partially exposed to limit the exposed conductive portion at the distal end of the outer sleeve. The outer sleeve can carry a dielectric spacer, which can limit a part of the inner lumen of the outer sleeve. The dielectric spacer can carry an active electrode and electrically isolate the active electrode from the outer sleeve. The dielectric spacer can be formed by any electrically insulating material that can preferably resist plasma degradation. The dielectric spacer can be formed by ceramic. The dielectric spacer is configured to electrically insulate the active electrode from the exposed conductive portion of the sleeve so that the sleeve can be electrically coupled to an RF generator and serve as a return electrode.

[0047] An exemplary tissue removal probe for mechanically and electrosurgically treating tissue is disclosed. The probe has a conductive tubular distal end with a cutting window on a first circumferential side and an electrically insulating spacer wrapped around a second circumferential side. An active electrode is secured to the electrically insulating spacer. The active electrode has two portions that are angularly offset from one another. A first portion of the portions extends circumferentially and axially along the tubular distal end. A second portion of the portions extends from the distal end of the first portion and spans the tubular distal end. The second portion has at least one flange that engages a corresponding notch in the electrically insulating spacer to resist separation of the active electrode from the electrically insulating spacer.

[0048] In some specific embodiments, the second portion extends perpendicular to the longitudinal axis. The second portion can define a distal-most surface of the tissue resection probe. The first portion can be axially tapered to allow for fine dissection of tissue at the distal end of the first portion. In some instances, the at least one flange can extend proximally into the electrically insulating spacer, or the at least one flange can include dual lateral flanges. The second portion can define a distally facing concave surface that helps deflect external forces on the active electrode during use. In some exemplary embodiments, the at least one flange can engage the notch and simultaneously axially position the active electrode to maintain an axial gap between the insulating spacer and the proximal end of the active electrode, the axial gap being configured to mitigate stress concentrations along the tubular distal end during use. In some exemplary embodiments, the insulating spacer can extend around the tubular distal end up to the cutting edge of the cutting window. The insulating spacer can extend over and cover the distal-facing end surface of the tubular distal end, thereby defining at least a portion of the distal-most end of the tissue resection probe. The active electrode may include a neck extending proximally from a first portion of the active electrode, the neck being configured to extend along a tunnel through the insulating spacer and thereby retain the active electrode in a second position proximally separated from the second portion. In some exemplary embodiments, the tissue resection probe may include a retaining clamp extending around an outer surface of the insulating spacer, and both the retaining clamp and the insulating spacer are electrically and mechanically coupled to the tubular distal end. Both the tubular distal end and the retaining clamp may define an outer surface of the tissue resection probe. The retaining clamp may include a distally extending tab on the same circumferential side of the active electrode, the tab being configured to arrange the proximal end of the active electrode and the retaining clamp according to a target spacing and thereby improve the electrosurgical tissue effect. The retaining clamp may include a dual lateral radial micro-motion end.

[0049] Another exemplary embodiment of a tissue resection probe for mechanically and electrosurgically treating tissue is disclosed. The probe includes a tubular distal end defining a return electrode. An orifice having a cutting edge is disposed on a first circumferential side of the tubular distal end. An insulator spacer is wrapped around a second circumferential side of the tubular distal end opposite the orifice. An active electrode is secured to the insulator spacer, the active electrode having a first portion extending axially and circumferentially along the tubular distal end and a retaining hook extending from a distal end of the first portion and angularly offset relative to the distal end of the first portion. The retaining hook is configured to attach the distal end of the active electrode to the insulator spacer and resist separation of the active electrode from the insulator spacer.

[0050] In some specific embodiments, the retaining hook can define a distal-facing surface of the tissue resection probe. The retaining hook can include a first protrusion extending toward the longitudinal axis of the tissue resection probe and a flange protrusion extending from the first protrusion, the flange protrusion being configured to fit within a recess at the distal end of the insulating spacer. The flange protrusion can extend along the longitudinal axis.

[0051] Also disclosed herein is a tubular end effector of a combined electrosurgical and mechanical resection assembly. The end effector includes a metal component that defines a cutting window on a first circumferential side of the tubular end effector. The metal component defines a return electrode of the assembly. The end effector also includes a ceramic spacer attached to the metal component such that the ceramic spacer forms a second circumferential side of the tubular end effector opposite the first circumferential side. A distal surface of the ceramic spacer includes a groove. The tubular end effector also includes an active electrode fixed to the ceramic spacer, the active electrode positioned opposite the cutting window. The active electrode includes a circumferential treatment surface and a retaining hook extending from a distal end of the circumferential treatment surface and angularly offset from the distal end of the circumferential treatment surface. The retaining hook includes at least one protrusion for operably coupling within the groove and thereby retaining the active electrode with the tubular end effector.

[0052] Disclosed herein is another exemplary embodiment of an arthroscopic tissue resection probe that may include an elongated shaft having an outer conductive sleeve and an inner sleeve. Each sleeve includes a distal region defining a cutting window, and the inner sleeve is capable of rotating to cut tissue. The probe may also include a ceramic body disposed on an outer surface of the outer sleeve along the distal region of the outer sleeve. The electrode is carried by the ceramic body, and a first suction opening extends through the electrode, the ceramic body, and the outer sleeve for aspirating fluid and ablation byproducts therethrough into the interior of the shaft. A second suction opening is at least partially defined by the conductive sleeve and is spaced apart from the electrode for aspiration therethrough into the interior of the shaft.

[0053] In some exemplary embodiments of an arthroscopic tissue resection probe, the electrode, ceramic body, and outer sleeve all include a 360-degree defined aperture spaced apart from the outer sleeve cutting window defining a first suction opening. The defined aperture is aligned for suction into the interior of the shaft through the defined aperture, the defined aperture being aligned along an axis transverse to the longitudinal axis of the elongated shaft. In some exemplary embodiments of the probe, both the conductive sleeve and the inner sleeve define 360-degree defined apertures, each spaced apart from the electrode and forming a second suction opening when aligned. Alternatively, the second suction opening can be defined by a boundary defined by the cutting edges of the two sleeves. The second suction opening can be positioned proximally relative to the electrode. The second suction opening can be positioned proximally relative to the first suction opening. The second suction opening can be positioned proximally relative to both cutting windows. The first and second suction openings can each have an opening size configured to balance suction through the first suction opening with a flow rate that forms a stable plasma at the electrode. The second suction opening can be configured to receive a fluid therethrough to cool the fluid drawn through the first suction opening and thereby reduce heating of the probe.

[0054] In another exemplary embodiment disclosed herein, an arthroscopic tissue resection probe can include an elongated shaft having an outer conductive sleeve and an inner sleeve, each sleeve having a distal region defining a cutting window, the inner sleeve being rotatable to cut tissue. A ceramic body is disposed on the distal region of the outer sleeve along an outer surface of the outer sleeve. An electrode is carried by the ceramic body, and a first suction opening extends through the electrode, the ceramic body, and the outer sleeve for aspirating fluid and ablation byproducts therethrough into an interior of the shaft. The probe also includes a clamp or collar covering a portion of the ceramic body and securing the portion of the ceramic body to the distal region, the clamp or collar being formed separately and secured directly to the conductive sleeve.

[0055] In some exemplary embodiments, a collar or clamp circumferentially sandwiches the ceramic body between the conductive sleeve and the collar or clamp. The collar or clamp may be proximally spaced from the cutting window. The collar or clamp may define a thin band that wraps completely around the entire conductive sleeve. The collar or clamp may be electrically conductive and in electrical communication with the conductive sleeve. DETAILED DESCRIPTION

[0056] The following discussion relates to various embodiments. Although one or more of these embodiments may be preferred, the disclosed embodiments should not be interpreted or otherwise used to limit the scope of the present disclosure, including the claims. In addition, those skilled in the art will understand that the following description has broad application, and the discussion of any embodiment is intended only as an example of that embodiment and is not intended to imply that the scope of the present disclosure, including the claims, is limited to that embodiment.

[0057] The present disclosure may generally include a system that combines mechanical resection with electrosurgical tissue treatment in a single device, including but not limited to tissue ablation, cutting, shrinkage, and coagulation. Combining these two approaches can reduce the need for multiple instruments during surgery (e.g., endoscopic or arthroscopic surgery). The mechanical tool edge surfaces of both the fixed member and the rotating member preferably include metal. The active electrode and the return electrode are preferably both disposed on a fixed outer sleeve of the tool. The fixed sleeve can provide electrical communication between the RF energy source and the electrode. The active electrode can also extend up to and around the distal-most surface of the device, which improves the accessibility of the active electrode to the target tissue and thereby improves the electrosurgical treatment of the target tissue. The electrode is also integral with or forms part of the outer sleeve portion and is configured to maintain a low profile distal end of the device, with minimal change in outer diameter by the addition of electrosurgical components.

[0058] Figure 1 , an overview of an exemplary surgical system 100 is shown, which includes a combined arthroscopic resection device 110 having a handle portion that includes a motor drive unit ("MDU") 112. The handle portion is removably coupled to a cutter 114. The MDU 112 can be operably coupled to a controller / power supply 120 via electrical wiring 130. Actuation of the MDU 112 causes a portion of the cutter 114 to move relative to another portion of the cutter to resect tissue. The combined device 110 can be configured to mechanically resect tissue in a manner similar to a commercially available metal scraper or file, wherein a high-speed rotating inner shaft is coupled to the MDU disposed within a fixed outer sleeve. The system 100 also includes an RF generator 140 for supplying RF power to the cutter 114 via RF electrical wiring 116. In some embodiments, the controller / power supply 120 and the RF generator 140 can be in a single housing. In some embodiments, the controller / power supply 120 and the RF generator 140 can communicate with each other. In some embodiments, one of the controller / power supply 120 and the RF generator 140 may be in communication with the ( 121 , 141 ) flow control device 220 .

[0059] The combined arthroscopic resection device 110 includes an aspiration tube 210 that can extend along the MDU 112 and can be coupled to a suction control device 220. The suction control device 220 can control the flow of fluid or negative pressure through the tube 210 and can include a suction pump or multiple suction pumps (not shown). The suction control device 220 can be a peristaltic pump having a rotor to provide and control the suction of tissue and fluid from the target site and along the device 110. In some embodiments, the suction can be fluidically coupled to wall suction that draws a vacuum at a consistent level. The suction control device 220 can include a pinch valve with multiple positions that clamps or releases the suction tube, or can include an alternative device that changes the size (orifice) of a fluid conduit associated with the suction tube. In some embodiments, the suction can be at least partially controlled by a control valve disposed on the MDU 112 that can selectively control a value associated with the suction through the device. The cutter 114 includes at least one lumen extending therethrough and communicating with the aspiration tube 210 for aspiration at the cutter distal portion 230 , such that fluid and debris may be aspirated through windows in the cutter distal portion 230 , flowing along the lumen and through the tube 210 .

[0060] The controller / power supply 120 may be, for example, a controller supplied by Smith & Nephew, Inc. of Andover, Massachusetts. Power scraper system or EP-18 scraper system. The generator 140 can be a commercially available generator, such as the COBLATION WEREWOLF system provided by Smith and Nephew, Inc. of Andover, Massachusetts. The cutter 114 is sized to suit the desired application. For example, the size of a cutter for the shoulder is different from the size of a cutter for the prostate. Applications include, for example, use in the shoulder, knee, and other joints, as well as in natural orifices such as the uterus, urethra, nasal cavity, and oral cavity. The MDU 112 includes a drive shaft (not shown) configured to selectively couple to the proximal end of the cutter 114 and can include coupling means similar to those disclosed in commonly assigned U.S. Patent No. 7,150,747, the complete disclosure of which is incorporated herein by reference.

[0061] refer to Figure 2, shows an example cutter 114 that includes an RF power cord 116 terminating at a free end in a connector 320. The connector 320 can have at least two pins 322 and 324 designed to connect to a generator 140 or a foot switch. Each pin connects to one of two separate conductors within the RF power cord 116 to provide both a supply path and a return path for the cutter 114. Additional pins (not shown) can provide further information to the RF generator / controller 140, such as the type of device and / or desired or candidate settings, such as a fluid flow setting or a power setting. Alternatively, the connector can include a series of pins configured to connect to a connector of the RF generator 140, such as the system described in commonly assigned U.S. Patent No. 9,333,024, the entire disclosure of which is incorporated herein by reference.

[0062] The cutter 114 can mechanically remove tissue in a manner similar to other commercially available mechanical removal devices. For example, the cutter 114 can include at least two concentrically arranged elongated sleeves or tubes, one within the other. One of the elongated tubes defines an outer sleeve that can be fixedly attached to the MDU 112 and serves as a stationary sleeve during use. The other sleeve is defined as an inner sleeve that is concentrically coupled to the MDU 112 with the outer sleeve so that it can rotate at high speed relative to the stationary outer sleeve. The cutter 114 can be attached to the MDU 112 using various hub-type structures, such as threaded connections and press-fit connections. Various embodiments of the MDU 112 include motor drive units manufactured by Smith & Nephew, Inc. of Andover, Massachusetts (e.g., part numbers 7205354, 7205355, and 7205971). A variety of cutting surfaces can provide mechanical cutting. Such surfaces include, for example, curved, burred, straight, serrated, or micro-cutting surfaces. Mechanical cutting is typically accomplished at speeds of thousands of cycles (eg, rotational or reciprocating motion) per minute.

[0063] Now go to Figures 3A-3D , which shows an exemplary embodiment of the distal end 300 of the cutter 114. The cutter distal end 300 includes a device for both mechanical and electrosurgical treatment of tissue. The cutter distal end 300 is generally tubular and includes an outer sleeve 310 having a window 320 on a first circumferential side of the sleeve 310. The window 320 has an edge surface 325 around the periphery of the window 320. At least a portion of the edge surface 325 is sufficiently sharp to cut tissue when used in combination with an inner sleeve 350. The inner sleeve 350 can extend along the lumen or bore of the outer sleeve 310 and can have a similar window 355 and an edge surface 356 that is configured to cooperate with the edge surface 325 to mechanically cut tissue when the inner sleeve is rotated.

[0064] The outer sleeve 310 is preferably a metal tube or conductive tube configured to provide an electrical path from the wire 116 along the sleeve 310. The outer sleeve 310 can be at least partially coated or covered by a layer or jacket 305 to electrically insulate a portion of the outer sleeve 310 and limit the exposed portion of the outer sleeve to a controlled area. For example, the proximal portion of the outer sleeve 310 adjacent to the MDU 112 can be exposed enough to electrically couple with the wire 116 and thereby electrically couple with the RF generator 140 (not shown). The distal portion of the outer sleeve 310 can also be exposed, exposing the metal edge surface 325 for mechanical resection. The exposed surface area of ​​the outer sleeve 310 (not coated or covered with an insulating material) defines the return electrode 360 ​​of the electrosurgical assembly.

[0065] The outer sleeve 310 carries an insulating spacer 380 and an active electrode 370. The active electrode 370 has a rounded outer surface and is at least partially nested within the spacer recess 386, thereby minimizing any additional size increase so that the device can fit within a 5 mm cannula. The active electrode 370 is electrically coupled to the RF generator 140 via a cable or wire extending along the cutter 114 (not shown) and the connector 320. The active electrode 370 and the associated cable are preferably electrically insulated from the outer sleeve 310, thereby allowing the outer sleeve 310 to act as a return electrode 360. The active electrode 370 is electrically isolated from the outer sleeve 310 / return electrode 360 ​​via the electrically insulating spacer 380. Since the active electrode 370 is intended to selectively ablate tissue and thus form plasma thereon, the spacer 380 is preferably an electrically insulating material that is also resistant to degradation by plasma or is plasma-resistant. The material may include ceramic or glass materials, such as aluminum oxide, zirconium oxide, etc.

[0066] The active electrode 370 should preferably be made of a material resistant to plasma degradation, such as tungsten, titanium, platinum, molybdenum, aluminum, gold, and copper. More specifically, the active electrode 370 can be a different material than the inner and outer sleeve materials. While stainless steel is preferred for a mechanical cutting edge, it tends to be less resistant to plasma degradation and is therefore not a preferred material for the ablation electrode 370. However, tungsten is a more brittle metal than stainless steel and is therefore less preferred as a cutting edge due to the potential for particle formation during mechanical ablation. Furthermore, the inventors have discovered that the distance between the edge or perimeter of the active electrode 370 and the cutting edge 325 should be at or above a predetermined distance. This predetermined distance is configured to inhibit unintentional plasma formation on the cutting edge 325. If the distance is closer than this, not only could plasma formation along the cutting edge 325 inadvertently result in tissue treatment on tissue other than the target tissue, but such plasma could also blunt or degrade the cutting edge 325, potentially frustrating mechanical ablation. The minimum distance between the peripheral edge of the active electrode 370 and the cutting edge 325 should be at least 2 mm measured along the outer surface of the device.

[0067] To minimize any additional diameter of the distal end 300 due to the electrosurgical components, the spacer 380 is a thin component that circumferentially engages the outer surface of the sleeve 310. The inner surface of the spacer 380 is contoured to mate with the outer surface of the sleeve 310 and can be attached using, for example, an adhesive. The spacer 370 is preferably formed of a high strength ceramic that provides structural integrity to the outer sleeve 310 and can increase the stiffness of the outer sleeve. The spacer 380 can be secured using an adhesive, and therefore a larger mating surface area for bonding is preferred for a higher level of retention between the two components. Figures 3A-3D , spacer 380 can extend proximally along outer sleeve 310 to at least sheath 305. While this proximal extension can improve the fixation of spacer 380, it also isolates the proximal side of return electrode 360. This can result in a more passive proximal side of the active electrode, less likely to form plasma. Therefore, distal end 300 can include a clamp or collar 390 annularly disposed around spacer 380. Clamp 390 can be conductive and in electrical communication with outer sleeve 310, thus forming a portion of return electrode 360. Clamp 390 can be welded 392 to outer sleeve 310. This thereby restores the desired proximity of the proximal side of return electrode 360 ​​adjacent to active electrode 370. Clamp 390 can also enhance the fixation between sleeve 310 and spacer 380. Spacer 370 can include an annular recess configured to receive clamp 390 therein while minimally increasing the outer diameter of distal end 300.

[0068] like Figure 3D As best shown in FIG, the inner sleeve 350 can define an elongated fluid aspiration conduit 312 along the inner sleeve that is in fluid communication with the aspiration tube 210 such that tissue debris formed during mechanical resection can be removed along the conduit 312 through the windows 320, 355. Figure 3D) forms a second inlet 371 into the conduit 312. The electrode 370, ceramic spacer 380, and outer sleeve 310 each define a suction orifice that can define a 360-degree defined orifice. The second inlet 371 defined by these orifices can be spaced apart from the outer sleeve cutting window 320, with the holes aligned to draw suction through the interior of the shaft and thereby through the conduit 312. The multiple orifices can be aligned along an axis transverse to the longitudinal axis of the elongated shaft. During electrosurgery, the inner sleeve 350 can be fixed and aligned to at least partially face the second inlet 371. An example of this is disclosed in more detail in International Patent Application No. PCT2020 / 019479, entitled “COMBINATION ELECTROSURGICAL AND MECHANICAL RESECTION DEVICE,” filed on February 24, 2020, which is commonly owned by the present applicant and incorporated herein by reference. The second inlet is configured to aspirate fluid passing through the active electrode 370 during use and remove fluid, debris, and plasma byproducts passing over the active electrode surface. Control of the value associated with the aspiration flow rate can also adjust the electrosurgical tissue effect, which is also disclosed in International Patent Application No. PCT2020 / 019479, entitled "COMBINATION ELECTROSURGICAL AND MECHANICAL RESECTION DEVICE," filed on February 24, 2020, which is commonly owned by the present applicant and incorporated herein by reference.

[0069] The distal end 300 may include means for regulating the temperature of the device, specifically, the outer surfaces of the device, such as the outer surfaces of the MDU 112. As fluid is drawn through the second inlet, while electrosurgical energy is supplied to the active electrode 370, the fluid temperature may be elevated. This elevated temperature may increase the temperature along the device's surfaces, including the device's handle and fluid lines. The surface area of ​​each of these components must be maintained below the touch temperature specified in the IEC 60601-1 standard. Because the MDU 112 is typically reusable, it may be formed from a metallic material, such as aluminum, which is generally more thermally conductive than, for example, disposable electrosurgical devices formed primarily of polymers. One embodiment may include a temperature sensor along the blade 114 that can communicate with the RF generator upon detecting a predetermined temperature increase. This may trigger and indicate a warning to the user or a change in RF energy output. The temperature sensor may be similar to those disclosed in at least the following US Patents: 8,355,799; 8,696,659; 9,452,008; or 10,420,601, commonly owned by the present applicant and incorporated herein by reference.

[0070] In some embodiments, to mitigate elevated temperatures, a cooler fluid can be directed through the device. This can regulate the temperature of the aspirated fluid passing through the device lumen 312 and then through the MDU 112. The distal end 300 can include a bypass aspiration pathway 363 completely spaced apart from the active electrode 370 to direct cooler fluid into and along the lumen 312. Path 363 can extend through openings in both the outer and inner sleeves (310, 350) and provide a route for aspirating a portion of fluid from within the joint cavity into the fluid aspiration conduit 312. This portion of the fluid can be relatively cooler than the fluid aspirated through the inlet 371, and thus relatively cooler than the fluid aspirated through the active electrode orifice 372. To some extent, depending on at least the power setting of the RF generator 140 and the fluid aspiration rate, the aspirated fluid and byproducts passing through the second inlet 371 can have an elevated temperature due to passage over the active electrode 370. Over time, this increased temperature can increase the external surface temperature of the MDU 112 and the tubing 210. The secondary path 363 can mix the cooler fluid with these increased temperatures and help cool the fluid, thereby reducing the increase in external surface temperature. Figure 3B 、 3C As shown in FIG3D , the bypass path 363 can be spaced proximally from the active electrode 370. The bypass path 363 can be disposed on a circumferential side opposite the active electrode 360. Being spaced apart from the active electrode 370 preferably draws fluid whose temperature is less affected by the energy of the active electrode into the fluid aspiration conduit 312. The bypass inlet 363 is defined by the overlapping holes in the inner sleeve 350 and the holes through the outer sleeve 310. Each hole can define a 360-degree defined hole or orifice.

[0071] return Figure 3A, shown in another optional bypass inlet 353 (in addition to or in lieu of bypass inlet 363), is defined by the relative position between the two windows (320, 355). This path 353 is adjustable, and if the temperature of the MDU increases, the inner sleeve 350 can be rotated to a position to adjust the orifice inlet size. For example, a temperature sensor positioned along the device 110 can sense a value indicative of an increased temperature, which temperature sensor communicates with the MDU 112. The MDU 112 can then rotate the inner sleeve 350 to a position that forms the bypass inlet 353. When the temperature sensor senses that the value indicative of the temperature has decreased to a predetermined value, the communication between the sensor and the MDU 112 can be configured to return the inner sleeve 350 to a fully closed configuration. When the temperature sensor senses that the value indicative of the temperature has increased to or remains at an increased value, the communication between the sensor and the MDU 112 can be configured to increase the inlet size by moving the inner sleeve 350 to a different position. In an alternative embodiment not shown, the bypass path can include multiple paths spaced apart from the active electrode 360. Alternatively, the bypass path may include at least one aperture (not shown) passing solely through the inner sleeve 350 , axially opposite the inner sleeve window 355 and thereby axially opposite the active electrode 370 .

[0072] The flow associated with the bypass inlets 363, 371 can also regulate the tissue effects and energy within any plasma formed at the active electrode 370. The combined device can be fluidly coupled to a wall draw, which can have a high draw flow rate, which can be too strong a flow to stably form a plasma at the active electrode 370. Excessively high flow rates can extinguish or destabilize any plasma formed at the active electrode 370. Therefore, the bypass inlets 363, 371 can balance or adjust the fluid flow rate through the electrode orifice 372 and thereby maintain a more stable plasma at the active electrode 370. For example, the RF generator can sense a value indicative of plasma stability, as disclosed in at least the following U.S. Patents: 8,192,424 and 10,448,988, commonly owned by the present applicant and incorporated herein by reference. The RF generator may communicate with the MDU 112 so that upon sensing a value associated with off-target plasma stability, the inner sleeve 350 may be moved to a position that forms the bypass inlet 371 and regulates fluid flow through the orifice 372 and, therefore, the plasma stability.

[0073] Now go to Figure 4A and 4B, shows a view of another embodiment of a distal end 400, with the inner sleeve removed for clarity. Similar elements are given the same reference numerals as distal end 300. Distal end 400 may include an outer sleeve 310 carrying an insulating spacer 480, which carries an active electrode 470. To maintain a minimum outer diameter for the device distal end 400, a thin spacer 480 is wrapped circumferentially around a portion of the outer sleeve's outer surface. As disclosed herein, spacer 480 is configured to electrically isolate active electrode 470 from outer sleeve 310, which is electrically connected as a return electrode. Spacer 470 wraps around the outer sleeve's outer surface for a limited distance to define an outermost boundary along and around outer sleeve 310. This boundary exposes a sufficient surface portion of outer sleeve 310 surrounding active electrode 470. The exposed surface portion defines the surface area of ​​return electrode 360. To maintain a minimal cross-sectional profile, spacer 480 is a thin component. Spacer 480 may be approximately 0.010 inches thick. The inner surface of the spacer 480 can mate with the outer surface of the sleeve 310 and be adhesively coupled to the outer sleeve 310. As previously disclosed herein, when it comes to having a strong bond between the sleeve 310 and the spacer 480, a large contact area with both is preferred. Therefore, the spacer 480 preferably extends circumferentially around the sleeve 310 and extends substantially proximally along the sleeve 310 from the active electrode 470. In other words, the spacer 470 can extend further around and along the sleeve 310 beyond the minimum required for electrical isolation between the sleeve 310 and the active electrode 470 to increase the fixation between the sleeve and the spacer 480.

[0074] However, due to this fixed bias, electrosurgical tissue effects may be impaired. The total surface area of ​​the return electrode 360 ​​decreases. As the total surface area of ​​the return electrode 360 ​​begins to approach that of the active electrode 470, tissue effects, including plasma, may inadvertently ignite the return electrode 360. The distance between the active and return electrodes may also be uneven around the perimeter of the active electrode 470. When the active electrode 470 is unevenly spaced from the return electrode 360 ​​at one end compared to the other, the tissue effect may only treat tissue along certain sides of the active electrode 470. The closer the active and return electrodes are, the higher the current density. High current density makes it easier for plasma to form on the active electrode. However, if the spacing between the active and return electrodes is greater in some peripheral portions of the active electrode 470 than in other portions, the current density in these areas is lower, and plasma is less likely to form around these portions. In some cases, plasma may only form along certain portions, which may damage the electrode or cause overly aggressive tissue effects. If the total distance between the return electrode and the active electrode periphery is too far, igniting the plasma becomes inconsistent or requires a higher voltage input to achieve. Therefore, a balance between a spacer 480 for a stronger bond with the sleeve 310 and a reliable uniform electrosurgical tissue effect is preferred.

[0075] Like clamp 390, distal end 400 includes a collar 490 wrapped around the outer surface of septum 480 at its proximal end. Collar 490 can extend 360 degrees around the cross-section of distal end 400. This not only provides additional fixation of the proximal portion of septum 380, but also serves as a return electrode 360. This collar 490 enhances the fixation between sleeve 310 and septum 480, avoiding interference with the internal rotating sleeve 350. Collar 490 can enhance the attachment of septum 480 to the outer sleeve, allowing it to withstand clinically relevant loads during surgery without compromising the integrity of any portion of the device. Collar 490 can extend around distal end 400 and be welded to outer sleeve 310 to secure it in place and establish consistent electrical communication with the outer sleeve 310. Collar 490 provides mechanical retention of septum 480. Thus, septum 480 is circumferentially sandwiched between outer sleeve 310 and collar 490. The spacer 480 may include an outer annular recess configured to nest at least a portion of the collar 490. The collar 490 may be proximally spaced from the window 320 and the active electrode 470. The collar 490 may have a thickness between 0.0020 and 0.0040 inches.

[0076] Regarding electrosurgical tissue effects, similar to clamp 390, collar 490 can be electrically conductive and can be in electrical communication with outer sleeve 310, thereby contributing to the effective surface area of ​​return electrode 360. Collar 490 can effectively move the perimeter of return electrode 360 ​​closer to the proximal end of active electrode 470, thereby forming a resulting return electrode perimeter that is more uniform around active electrode 470. In other words, due to the addition of collar 490, the spacing between active electrode 470 and return electrode 360 ​​is made more uniform around more sides of active electrode 470. Collar 490 wraps tightly around spacer 480 and outer sleeve 310 and can include weld 480 to securely secure collar 490 to outer sleeve 310. An exemplary location for weld 480 is shown. Another example can include a circumferential laser weld around the mating portions of sleeve 310 and collar 490. Electrical communication between the outer sleeve portion of the return electrode 360 ​​and the collar 490 may be achieved through weld 480 and surface contact.

[0077] Figures 5A-5G Another distal end embodiment 500 similar to the previously disclosed embodiment is shown. Similar elements are given the same reference numerals as the distal ends 300 and 400. The distal end 500 includes an outer sleeve 510 in which an inner sleeve 350 is coaxially disposed. The inner sleeve 350 can be rotated relative to the outer sleeve 510 to mechanically excise tissue via a laterally disposed window. The outer sleeve 510 is at least partially covered by an insulating spacer 580, and the spacer 580 carries a source electrode 570. The return electrode 360 ​​can include a plurality of components or bodies having exposed conductive surfaces and electrically connected to each other. These components can include the exposed conductive surfaces of the inner sleeve 350, the exposed conductive surfaces of the outer sleeve 510, and the externally exposed conductive surfaces of the retaining fixture 590.

[0078] Figure 5B, with the inner sleeve 350 removed to simplify the drawing. The outer sleeve 510 defines an elongated sleeve having a cutting window 520 on a first circumferential side of the distal end 500. The outer sleeve 510 extends proximally and can be fixedly coupled to a hub configured to operably couple with a handle end, which may include the MDU 112. The outer sleeve 510 includes a suction orifice 512 extending through the thickness of the outer sleeve wall on a second circumferential side, opposite the window 520. The orifice 512 can communicate with a corresponding orifice through the active electrode 570 to aspirate fluid and debris therethrough while treating tissue. The distal end of the outer sleeve 510 can define a reduced outer diameter portion 514 formed by reducing the thickness of the sleeve wall. This portion 514 defines a circumferential surface that engages the inner surface of the insulating spacer 580. The reduced diameter of the reduced outer diameter portion acts as a recess and maintains the smaller overall profile of the distal end 500. The outer sleeve 510 extends until around a distal end 516 that curves toward the longitudinal axis of the sleeve 510 , the curve extending until and including an angled cut edge 525 of the window 520 .

[0079] The spacer 580 is sized to mate with at least the reduced diameter portion 514 of the outer sleeve 510 and covers the circumferential side of the sleeve 510 opposite the window 520. The spacer 580 extends over the distal tip 516 of the sleeve and is fixedly coupled thereto. The spacer 580 may define a single body and may have a contoured inner surface that is contoured to match and directly engage the outer surface of the sleeve 510 for mating surface-to-surface contact therebetween. The inner surface of the spacer 580 may be adhesively coupled to the outer sleeve 510. The spacer extends around the distal tip 516 to space the active electrode 570 from the sleeve 510, and thereby from the return electrode 360, to reduce inadvertent plasma formation on the sleeve 510. Thus, the spacer 580 defines a distal-facing surface at the distal-most end of the distal end 500. The fixation of the spacer 580 to the sleeve 510 around the distal tip 516 can be particularly relevant during use because the very distal tip can be used to elevate and dissect tissue, placing an elevating load on the active electrode 570 and the spacer 580. Wrapping the spacer 580 around the distal tip 516 improves the fixation of the spacer 580 to the sleeve 510. The spacer 580 can extend around the sleeve 510 up to the beveled cutting edge boundary 525 of the sleeve window 520. The spacer 580 can surround at least the top circumferential half of the sleeve 510. As shown in FIG. Figure 5C and Figure 5D, the spacer 580 can cover at least half of the circumference of the sleeve 510 at the distal end 500. Wrapping the spacer 580 around the sleeve 510 not only increases the surface area available for bonding between the sleeve 510 and the spacer 580, but also creates a more equal spacing between the proximal and distal edges of the active electrode 570 and the return electrode 360. The spacings G1 and G2 are substantially equal to each other, as shown in FIG. Figure 5D Additionally, the inventors have discovered that, in use, the primary force on the distal end of the device comes from the distal-most end (F) in the proximal direction to lift the spacer 580 and / or active electrode 570 upward and thereby to separate the active electrode 570 and / or spacer 580 from the sleeve 510. The spacer 580 preferably extends over and is bonded to the distal-facing surface of the sleeve 510.

[0080] The spacer 580 includes a plurality of recesses for nesting and securing the active electrode 570 and the clamp 590. The retaining clamp 590 can surround the spacer 580 and be located within a notch or recess 582 formed on the outer surface of the spacer 580. The clamp 590 can be a stainless steel stamped and formed clamp that fits around the spacer 580. The recess 582 can mirror the profile of the clamp 590 and can help form a smoother and more continuous outer surface of the distal end 500, thereby eliminating or reducing notch points along the distal end 500. The clamp 590 can be welded to the outer sleeve 510 to retain the clamp 580 and electrically couple the clamp to the outer sleeve. As explained herein, the clamp 590 provides a supplemental fixation between the spacer 580 and the sleeve 510. The clamp 590 can define a body portion 591 and free ends 592a, 592b. The free ends 592a, 592b can be shaped relative to the body portion 591 and can move radially inward. The radial micromotion preferably follows the contour of the spacer 580 and the transition from the spacer 580 to the sleeve 510. The free ends 592a, 592b are preferably fixedly coupled to the outer sleeve 510. The body 591 can define a distally extending tab 593 configured to create a more uniform spacing between the active electrode 570 and the return electrode 360. The tab 593 can extend distally toward the active electrode 570 on the same circumferential side of the sleeve 510 as the active electrode 570. The tab 593 can define a circumferential width equal to the circumferential width of the corresponding active electrode. Without the tab 593, the spacing between the proximal portions of the active electrode 570 and the return electrode 360 ​​can be significantly non-uniform around the active electrode 570, biased toward the distal end of the active electrode 570. As previously explained, this can bias plasma formation and tissue effects strongly toward the distal tip of the active electrode 570 and hinder uniform and controlled electrosurgical tissue effects. The tab 593 has a lateral or circumferential extension and can define a distal-most edge that surrounds or approaches the proximal edge of the active electrode 570. The addition of the clamp 590 also increases the total exposed surface area of ​​the return electrode 360 ​​that can contact the conductive fluid, mitigating any unintended tissue effects at the return electrode 360. For example, the clamp 590 can increase the effective return electrode 360 ​​surface area by up to 50% and define an active electrode 570 to return surface area ratio closer to 1:7.

[0081] The spacer 580 includes a fluid suction orifice 586 that is in fluid communication with and overlaps the corresponding orifice 512 through the sleeve 510 and the active electrode orifice 572. All three orifices communicate to remove tissue debris and fluid from the target site along a device that can be coupled to, for example, a vacuum source. The spacer orifice 586 can define a boss orifice (e.g., Figure 5F). A boss may extend through the sleeve aperture 512 to increase the insulating spacing between the active and return electrodes, thereby inhibiting plasma from being ignited through the apertures (512, 572, 586) to the inner or outer sleeve.

[0082] The spacer 580 also nests and holds the active electrode 570 in at least two discrete positions. The two positions can be separated axially by a spacer circumferential surface 588. The first holding position includes an axial tunnel 587 that accommodates and covers the active electrode leg 577. The axial tunnel 587 can be slidably engaged with the leg 577 to hold the proximal end of the active electrode 570. An adhesive can be inserted into and along the tunnel 587 to improve retention and limit fluid ingress along the tunnel. The proximal end of the leg 577 can be electrically coupled to a wire extending along the device (not shown).

[0083] Extending distally from tunnel 587 is a circumferential surface 588 configured to support the circumferential portion 571 of active electrode 570. Active electrode 570 is a single body having circumferential portion 571 and second electrode portion 578. Circumferential portion 571 can define a first treatment surface 571a of active electrode 860, disposed on the circumferential side of distal end 500 opposite window 520. First treatment surface 571a can conform to the outer contour of distal end 500. First treatment surface 571a can taper to a narrower distal end for more delicate dissections. The proximal edge 573 of treatment surface 571a is preferably axially spaced from the corresponding distal edge 584 of spacer 580. This axial spacing provides relief when active electrode 580 flexes during use. Without this spacing, proximal edge 583 could place damaging stresses on spacer edge 584.

[0084] The spacer 580 also retains the active electrode 570 at a distal position axially separated from the proximal retaining position (legs 577). The distal end of the active electrode includes a second electrode portion 578 angularly offset from the first portion 571 and from the longitudinal axis of the distal end 500. The second electrode portion 578 can define a distally-facing treatment surface 579 extending across the distal-most end of the distal end 500. The second electrode portion 578 has a radial extent. The surface 579 can further include a sloped portion 579a configured to deflect a force (F) that could separate or peel the active electrode 570 from the spacer 580 during treatment. The slope 579a defines a distally-facing concave surface. The slope 579a can taper as it extends toward the longitudinal axis to extend proximally. The treatment surface 579 generally enhances the performance of the tip of the active electrode 570. It extends the functional base of the distal tip of the active electrode 570.

[0085] The second electrode portion 578 extends from the distal end of the first treatment portion 571 and can define a hook shape. The second electrode portion 578 can engage a mating surface of a spacer recess 581. The spacer recess 581 can extend from the distal-most surface of the spacer 580. The second electrode portion 578 can have an extension with at least one lateral flange 595 or protrusion disposed at the end of the extension. Figure 5E Shown is a pair of opposing lateral flanges 595a, 595b defining a triangular shape. A mating recess 581 in the spacer 580 can receive and retain the opposing lateral flanges 595a, 595b. The second electrode portion 578 defines a second discrete retaining portion. The notch or recess 581 can define opposing grooves to receive the opposing lateral flanges 595a, 595b. As previously explained, when loaded (F) at the distal end, the electrode 570 may tend to rotate about the electrode neck 577. If significant rotation is allowed, permanent displacement of the electrode 570 or fatigue failure of the neck may result. This second retaining position at the distal end of the electrode 570 helps mitigate this failure mode.

[0086] The flange and the mating groove are configured to engage one another and secure the electrode distal end to the spacer. Figure 6 and Figure 7 Other exemplary embodiments are shown having alternative flange and groove shapes. Figure 6 A distal view of the distal end 600 is shown, wherein the active electrode 670 includes a second electrode portion 670 defining the distal-most end of the distal end 600. The second electrode portion 670 includes "T"-shaped dual lateral flanges 695a, 695b. The spacer 680 includes mating grooves 685a, 685b configured to engage the dual lateral flanges 695a, 695b and secure the distal end of the electrode 670 to the spacer 680. Figure 7 A distal view of an exemplary embodiment distal tip 700 is shown, wherein the active electrode 770 includes a second electrode portion 775 at the distal-most end of the distal tip 700. The second electrode portion 775 includes curved dual lateral flanges 795a, 795b.

[0087] Figure 8A and 8B , which, for ease of understanding only, shows a distal end 800 having an active electrode 870 and a spacer 860. The active electrode 870 includes dual lateral rails 875a, 875b along the lateral edges of the active electrode 870 that operably engage dual lateral slots along the spacer 860. While this embodiment provides a longer engagement length, it may be necessary to increase the cross-sectional area of ​​the distal end 800, thereby creating a larger profile end compared to the distal end 500 having a distal retaining hook-shaped end.

[0088] exist Figure 9A and 9B Another exemplary embodiment of the distal end 900 is shown in FIG. Like components are given like reference numerals. In this embodiment, a collar 990 can function in a manner similar to at least the clamp 390, 590, or collar 490 and can surround the spacer 980. The collar 990 can include two axially extending tabs 995a, 995b. Each tab 995a, 995b can extend along a lateral side relative to the active electrode 570 to surround a larger perimeter of the active electrode 570. The spacer 980 can include a corresponding notch or recess (not shown) for receiving the collar 990 therein. The recess can match the shape of the collar 990 and can help form a smoother and more continuous outer surface, thereby eliminating or reducing notches along the collar 990. The collar 990 can be similar in material and construction to the clamp 390 or 590 or collar 490. The collar 990 can be welded to the outer sleeve 910 to retain the collar 990 and electrically couple it to the outer sleeve. Spacer 980 can be adhesively coupled to outer sleeve 510, with collar 990 providing supplemental fixation between spacer 980 and sleeve 910. Two distally extending tabs 995a, 995b are configured to improve the spacing between active electrode 570 and return electrode. As explained herein, this can improve electrosurgical tissue effects, as previously explained. The addition of collar 990 also increases the overall surface area of ​​the return electrode, making it larger than that of clamp 590. For example, collar 990 can increase the surface area by up to 100% and maintain an active electrode 570 to return surface area ratio closer to 1:10.

[0089] Figures 10A-10E Another exemplary embodiment of a combined tissue resection probe distal end 1000 is shown, which is configured to function in a similar manner to the previously disclosed embodiments and therefore includes similar components. For ease of understanding, Figure 10AOnly the spacer and active electrode are shown. Distal end 1000 includes an active electrode 1050 coupled to spacer 1060 in a manner similar to electrode 570 and spacer 580. Active electrode 1050 includes a first treatment portion 1052 defining the outer circumferential surface of distal end 1000. This first treatment surface may taper as it extends distally to the more delicate distal end, allowing for finer tissue dissection. Active electrode first treatment portion 1052 may include a through-going suction orifice 1055 that is in fluid communication with a suction conduit extending along the probe shaft, similar to the previous embodiment. Active electrode 1050 also includes a distal hook 1056 extending toward the longitudinal axis of distal end 1000 of the device. Distal hook 1056 has a distal-facing surface 1057 that allows for electrosurgical treatment of tissue at the extreme distal end of the probe. Distal-facing surface 1057 may have a lateral extent that is more square than distal-facing surface 578 of the hook. This can increase the structural integrity of the distal hook 1056. The distal hook 1056 is configured to secure the active electrode 1050 with the spacer 1080 at the distal-most end.

[0090] Figure 10B An exploded view of the components of the distal end 1000 is shown, including the inner sleeve 310, the outer sleeve 1010 which may define a portion of the return electrode 360, the insulating spacer 1060, the clamp 1090 which may also define a portion of the return electrode 360, and the active electrode 1050. Embodiment 1000 is similar to embodiment 500 in most respects except where otherwise noted. For example, in embodiment 1000, the distal hook 1056 engages the spacer 1060 with the proximally extending flange 1059 at the distal end. The spacer 1060 has corresponding cavities 1062 and recesses 1064 for receiving and engaging the hook 1056, as shown in FIG. Figure 10E As shown in more detail in .

[0091] like Figure 10E, showing a proximally extending flange or protrusion 1059. Spacer 1060 includes a contoured cavity 1062 extending up to and including the distal-most surface of spacer 1060. Cavity 1062 is configured to engage distal hook 1056 therein and engage protrusion 1059. Distal hook 1056 is at least partially recessed within cavity 1062 to secure active electrode 1050 while allowing surface 1057 to approach tissue at the distal tip of the probe. Cavity 1062 includes a notch 1064 extending further proximally into the cavity and configured to receive protrusion 1059. Notch 1064 is configured to receive and engage protrusion 1059 to secure the distal end of active electrode 1050 during use of the probe and mechanically resist separation of active electrode 1050 from spacer 1060. Notch 1064 and cavity 1062 are also configured to limit the axial position of active electrode portion 1052. The recess 1064 and cavity 1062 cooperate with the active electrode 1050 to space the proximal edge 1053 of the active electrode treatment portion 1052 from the spacer distal edge 1066 by a predetermined axial distance. During assembly, the active electrode 1050 can be slid proximally along the spacer 1060 to lie flat against the spacer. The active electrode 1050 is slid upward until the protrusion 1059 is disposed within the cavity 1062 and engages the proximal surface of the recess 1064. The active electrode 1050 can then be secured in place, for example, via an adhesive. This position defines an axial spacing between the edges 1066 and 1053 that is configured to prevent stress from being transferred to the spacer 1060 via bending and flexing of the active electrode during use. During device use, normal conditions can bend and flex the distal end 1000. Figure 10C The top side of the distal end 1000 is shown, showing a tapered active electrode portion 1052 including a squared-off distal-facing surface 1057a.

[0092] Those skilled in the art will recognize that the present disclosure may be implemented in other specific forms without departing from its spirit or essential characteristics. The foregoing examples are therefore to be considered in all respects as illustrative, rather than limiting, the disclosure described herein. The scope of the present disclosure is therefore indicated by the appended claims rather than by the foregoing description, and therefore all changes within the meaning and scope of equivalents of the claims are intended to be included therein.

Claims

1. A tissue removal probe for mechanically removing tissue and electrosurgically treating tissue, comprising: an electrically conductive tubular distal end having a cutting window on a first circumferential side; an electrically insulating spacer wrapped around a second circumferential side of the tubular distal end; an active electrode secured to the electrically insulating spacer, the active electrode defining two portions angularly offset from one another, the two portions comprising a first portion extending circumferentially and axially along the tubular distal end, a second portion extending from the distal end of the first portion and spanning the tubular distal end, the second portion having at least one flange configured to engage a notch in the electrically insulating spacer to resist separation of the active electrode from the electrically insulating spacer, the second portion extending up to and around a distal-most surface of the tissue resection probe and defining the distal-most surface of the tissue resection probe. 2 . The tissue resection probe of claim 1 , wherein the second portion extends perpendicular to the longitudinal axis. 3 . The tissue resection probe of claim 1 , wherein the first portion is axially tapered and configured to finely dissect tissue at a distal end of the first portion.

4. The tissue resection probe of claim 1, wherein the at least one flange extends proximally into the electrically insulating spacer.

5. The tissue resection probe of claim 1, wherein the at least one flange comprises dual lateral flanges.

6. The tissue resection probe of claim 1, wherein the second portion defines a distally facing concave surface configured to deflect external forces on the active electrode during use.

7. The tissue resection probe of claim 1, wherein the insulating spacer extends around the tubular distal end to a cutting edge of the cutting window.

8. The tissue resection probe of claim 1, wherein the insulating spacer extends over the distally facing end surface of the tubular distal end to cover the distally facing end surface, thereby defining at least a portion of the distal-most end of the tissue resection probe.

9. The tissue resection probe of claim 1 , wherein the active electrode includes a neck extending proximally from the active electrode first portion, the neck being configured to extend along a tunnel through the insulating spacer and thereby maintain the active electrode in a second position proximally separated from the second portion.

10. The tissue resection probe of claim 1, further comprising a retaining clamp extending around an outer surface of an insulating spacer, and wherein both the insulating spacer and the retaining clamp are electrically and mechanically coupled to the tubular distal end.

11. The tissue resection probe of claim 10, wherein the tubular distal end and the retaining clamp both define an outer surface of the tissue resection probe.

12. The tissue resection probe of claim 11 , wherein the retaining fixture includes a distally extending tab disposed adjacent the active electrode, the tab being configured to arrange the proximal end of the active electrode and the retaining fixture according to a target spacing and thereby improve electrosurgical tissue effect.

13. The tissue resection probe of claim 10, wherein the retaining fixture comprises dual lateral radial fine motion ends.

14. The tissue resection probe of claim 1 , wherein the at least one flange is configured to engage the notch and simultaneously axially position the active electrode to maintain an axial gap between the insulating spacer and the proximal end of the active electrode, the axial gap being configured to relieve stress concentration along the tubular distal end during use.

15. A tissue removal probe for mechanically removing tissue and electrosurgically treating tissue, comprising: a tubular distal end defining a return electrode, the return electrode comprising: an orifice having a cutting edge, the orifice disposed on a first circumferential side of the tubular distal end; an insulating spacer wrapped around a second circumferential side of the tubular distal end opposite the orifice; an active electrode carried by the insulating spacer, the active electrode having a first portion extending axially and circumferentially along the tubular distal end, and a retaining hook extending from and angularly offset relative to the distal end of the first portion, and wherein the retaining hook is configured to secure the active electrode to the insulating spacer to resist separation of the active electrode from the insulating spacer, the retaining hook defining a distal-most surface extending up to and around the distal-most surface of the tissue resection probe, and the distal-most surface of the tissue resection probe.

16. The tissue resection probe of claim 15, wherein the retaining hook comprises a first protrusion and a flange protrusion, the first protrusion extending toward the longitudinal axis of the tissue resection probe, the flange protrusion extending from the first protrusion, the flange protrusion being configured to fit within a recess at the distal end of the insulating spacer.

17. The tissue resection probe of claim 16, wherein the flange protrusion extends along the longitudinal axis.

18. A tubular end effector combining electrosurgery and mechanical resection components, comprising: a metal component defining a cutting window on a first circumferential side of the tubular end effector, the metal component being configured as a return electrode; a ceramic spacer fixedly coupled to the metal component such that the ceramic spacer forms a second circumferential side of the tubular end effector opposite the first circumferential side, and wherein a distal end of the ceramic spacer includes a groove; an active electrode secured to the ceramic spacer, the active electrode positioned opposite the cutting window, wherein the active electrode includes a circumferential treatment surface and a retaining hook extending from and angularly offset relative to a distal end of the circumferential treatment surface, the retaining hook including at least one protrusion for operatively coupling within the recess and thereby retaining the active electrode with the tubular end effector, the retaining hook extending up to and around a distal-most surface of the tissue resection probe and defining a distal-most surface of the tubular end effector.

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