Abstract:
Disposable electrosurgical probes for treating tissue, and surgical procedures that make use of such probes. Such a probe includes a working element, an elongate sheath secured to the working element, and a core member within the sheath. At least one active electrode and conductor are disposed in a first of a plurality of internal longitudinal channels within the core member. The electrode is adapted to extend from a distal end of the sheath and configured to perform cutting, coagulation, or ablation of tissue with radio frequency current. The probe further includes a fluid passage defined by at least a second of the internal longitudinal channels within the core member. At least the working element, the sheath, and the core member are formed of a disposable material.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 62/000,262, filed May 19, 2014, the contents of which are incorporated herein by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    The present invention relates to electrosurgical probes for treating damaged, diseased or enlarged tissue, and to surgical procedures that make use of such probes. 
         [0003]    Electrosurgical effects can be accomplished by applying a highly damped radio frequency (RF) current to tissue through an electrode in the form of an active (+) electrode (tip) of an electrosurgical (electrocautery) probe, from which the RF current flows to a ground (−) electrode. RF electrosurgical probes (RF probes), such as those commonly used in urological and hysteroscopic procedures, are said to be monopolar or bipolar or said to have a monopolar or bipolar operating mode, depending on their electrode configuration. RF probes operating in a monopolar mode utilize a single (active) electrode (tip) and rely on external grounding of a patient (e.g., a ground electrode in the form of a patient plate) to cause current flow from the active electrode to tissue of the patient. RF probes operating in a bipolar mode have two electrodes, typically designated as active and return electrodes, and current flow is localized between these electrodes. As it passes through tissue from the active electrode to the ground or return electrode, the RF current resects (cuts), coagulates and/or ablates (desiccates) the tissue, depending on the type of probe and the RF power and wave length combinations used. RF electrosurgical probes are typically placed through a resectoscope (used in urological procedures), hysteroscope (used in gynecological procedures) or other device, which is often equipped with a telescope so that the active electrode of the probe is in direct view of the surgeon at all times. Irrigating solutions are commonly used as a distention medium and a coolant for the active electrodes of RF probes during electrosurgical procedures. 
         [0004]    Resectoscopes and hysteroscopes (hereinafter referred to as electrosurgical probes) have been used for decades to diagnose and treat medical conditions in the human bladder and the uterus, respectively. Electrosurgical resection refers to procedures by which damaged, diseased or enlarged tissue is removed with an electrosurgical probe. A nonlimiting example is transurethral resection of the prostate (TURP), in which prostate tissue is removed by means of an active electrode (for example, a cutting loop) passed through the urethra by means of a resectoscope. This procedure has served as the historical treatment of benign prostate hypertrophy (BPH)), commonly known as “enlarged prostate,” and prostatitus. Bladder tumors and cysts in men and women are also treated by electrosurgical resection. Electrosurgical ablation refers to procedures by which an electrosurgical probe is used to ablate (dessicate) tissue, which eventually sloughs off instead of being immediately removed on contact with the electrode. A nonlimiting example of an electrosurgical ablation procedure is endometrial ablation to treat endometriosis in women, in which tissue is removed by means of roller that serves as the active electrode. Another example is transurethral ablation of the prostate (TUAP), in which prostate tissue is ablated by means of an electrocautery probe passed over a stylet/obturator or guide wire, through the prostatic urethra. 
         [0005]    In addition to its electrode, an electrosurgical probe typically includes a working element equipped with a power cord for connection to an RF electrosurgical current generator, and a sheath that extends from the working element and through which one or more conductors are routed to deliver RF current to the electrode protruding from a distal end of the sheath. The probe is also typically equipped with a telescope and/or light source disposed in one or more internal channels within the sheath to allow direct vision during placement and use of the probe. The electrode and its conductor(s) may be capable of reciprocal movement within the sheath through the operation of an actuation lever of the working element. The sheath may also define an internal flow channel to enable an irrigation fluid to be delivered for immersion cooling of the electrode. The RF generator, light source, and telescope are capital equipment and available in a typical surgical suite. While electrosurgical probe electrodes are disposable and therefore do not require sterilization after use, the remaining components of a electrosurgical probe, including the working element, sheath and telescope, are typically formed of stainless steels or another durable metallic material and durable heat-resistant plastics that enable these components to be reused following re-sterilization, for example, using an autoclave and/or ethylene oxide gas. As such, electrosurgical probes typically have high initial purchase costs. The distal end of the sheath is often equipped with a plastic tip that becomes damaged over time, in some cases after a single use, as a result of the high RF current levels, necessitating that the sheath undergo an expensive and time-consuming repair. Also due to the RF currents, metal components of an electrosurgical probe require electrical insulation to protect the surgeon from receiving shocks and burns during use of the probe. Even so, surgeons are commonly required to wear two pairs of latex gloves as a safety precaution. 
         [0006]    Sterilization can be a complicated process, particularly in view of the internal channels within the sheath that accommodate a light source, telescope, and/or cooling flow stopcocks and channels. Furthermore, components of reusable electrosurgical probes are conventionally individually reprocessed, sterilized, and packaged, and then kept in drawers, cabinets, and carts accessible to the surgical team. If any of the components are unavailable or the wrong size, the procedure cannot go forward. Generally, hospitals have additional electrosurgical probes on hand in case one fails during surgery. However, at times when case loads are high, a physician may be forced to either wait for another unit to be sterilized or cancel the surgery. 
         [0007]    Since the late 1980&#39;s, the use of disposable (sterile, one-time use) surgical instruments and devices has dramatically increased in the United States. This trend of cycling from reusable to disposable surgical instruments and devices is taking place now in countries around the world as their economies grow, as is the awareness of the risks and costs associated with hospital-acquired infections, especially those in the operating room. This trend is driven by numerous factors, such as sterility assurance, quality/performance, reducing cross contamination, and cost factors (cost control, convenience, and patient charges). 
       BRIEF DESCRIPTION OF THE INVENTION 
       [0008]    The present invention provides electrosurgical probes for treating damaged, diseased or enlarged tissue, and to surgical procedures that make use of such probes. 
         [0009]    According to one aspect of the invention, a disposable electrosurgical probe includes a working element, an elongate sheath secured to the working element, and a core member within the sheath. The core member has a plurality of internal longitudinal channels, and at least one active electrode and conductor are disposed in a first of the internal longitudinal channels. The conductor is adapted to carry a radio frequency current to and from the electrode, and the electrode is reciprocable within the sheath, adapted to extend from a distal end of the sheath, and configured to perform cutting, coagulation, or ablation of tissue when the radio frequency current flows to the electrode. The disposable electrosurgical probe further includes means associated within the working element for reciprocating the electrode relative to the sheath, and a fluid passage defined by at least a second of the internal longitudinal channels of the core member. At least the working element, the sheath, and the core member are formed of a disposable material. 
         [0010]    According to another aspect of the invention, a method of using the disposable electrosurgical probe to perform a medical procedure includes placing the electrode of the disposable electrosurgical probe within a patient, performing an electrosurgical procedure on the patient using the disposable electrosurgical probe, and disposing of the working element, the sheath, and the core member after performing the procedure. 
         [0011]    A technical effect of the invention is that the disposable electrosurgical probe can be offered as a kit, in which the working element, sheath, core member, and one or more electrodes are all disposable components of the kit. 
         [0012]    Other aspects and advantages of this invention will be better appreciated from the following detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]      FIG. 1  is a side view representing an electrosurgical probe in accordance with a nonlimiting embodiment of this invention. 
           [0014]      FIG. 2  represents an electrode protruding from a distal end of a sheath of the electrosurgical probe of  FIG. 1  as a result of operating a handle of the working element. 
           [0015]      FIG. 3  represents a partial cutaway view of the distal end of the sheath of  FIG. 2 , showing the electrode protruding therefrom and revealing an electrode connection and irrigation tube within the sheath. 
           [0016]      FIG. 4  is a perspective view of the probe of  FIG. 1 , showing a partial cutaway of the distal end of the sheath. 
           [0017]      FIG. 5  represents a detailed view of the distal end of the sheath of  FIG. 4 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0018]      FIGS. 1 through 5  depict an electrosurgical probe  10  in accordance with a nonlimiting embodiment of the present invention. The drawings depict the probe  10  as a resectoscope, though other electrosurgical probes capable of use in a wide variety of procedures are also within the scope of the invention. The probe  10  is represented as including a sheath  12  through which conductors can be routed to one or more electrodes disposed at a distal end  14  of the sheath  12 . The conductors carry a current, preferably an RF current, generated by an electrosurgical generator (not shown) that is connected to the probe  10  via a power cord  16  extending from a working element  18  of the probe  10 . The probe  10  can be a monopolar or bipolar RF electrosurgical probe.  FIGS. 1 through 5  depict a single electrode  20  configured as a cutting loop (wire), though other electrode configurations are possible and within the scope of this invention, for example, such well-known types as ball tip, disk, roller tip, barrel, cone, point, knife, flat band, coagulating, and punctate electrodes. As a cutting loop, the electrode  20  is represented as electrically connected to one or more insulated conductors  21  to define an active (+) pole of the RF circuit. 
         [0019]    The electrode  20  and its conductors  21  are preferably capable of reciprocal movement within the sheath  12 , as evidenced by the retracted and extended positions of the electrode  20  depicted in  FIGS. 1 and 2 , respectively. Movement of the electrode  20  and conductors  21  relative to the sheath  12  can be effected through the operation of an actuation lever  22  of the working element  18 . The electrode  20  and its conductors  21  are disposed in an internal longitudinal channel  26  defined within a core member  24  that is coaxially disposed within an internal passage  25  defined by the sheath  12 , such that the core member  24  is completely surrounded by the sheath  12 . The electrode  20  and its conductors  21  may be reciprocably disposed in the internal channel  26 , or the core member  24  may be reciprocably disposed within the passage  25  of the sheath  12 . As evident from  FIGS. 4 and 5 , the core member  24  has a circular-shaped outer circumference defined by a tubular outer wall  28  of the member  24 , and an internal web  30  that defines the internal channel  26  as well as a second internal longitudinal channel  32  in which a telescope  34  is represented as being received to allow direct vision during placement and use of the probe  10 . The internal channels  26  and  32  preferably have circular cross-sections and the core member  24  is represented as having a plane of symmetry through the channels  26  and  32 , with the result that the channels  26  and  32  are between two internal longitudinal channels  36  (one of which is visible in  FIGS. 4 and 5 ) that are defined by the remainder of the circular interior cross-section of the core member  24  surrounded by the outer wall  28 . As a result of the circular cross-sectional shapes of the outer wall  28  and channels  26  and  32  and the symmetrical shape of the core member  24 , the channels  36  are substantially identical mirror-images of each other and have fan-shaped cross-sections. Either or both of the channels  36  can serve as an irrigation tube that enables an irrigation fluid to be delivered to the electrode  20 , for example, to perform immersion cooling of the electrode  20 . Alternatively, a separate tube could be located within either or both channels  36  through which an irrigation fluid could flow through the sheath  12 . In either case, at least one of the channels  36  is adapted to be fluidically coupled to a fluid source, for example, via one or more irrigation ports  38  located on the working element  18 . As a result of the channels  36  being disposed on opposite sides of the channel  26  containing the electrode  20 , the channels  36  are able to direct irrigation fluid to opposite sides of the electrode  20 , thereby enveloping the electrode  20  and promoting the desired effect of the irrigation fluid in close proximity to the electrode  20 . 
         [0020]    Whereas the telescope  34 , RF generator, and other such components including light sources are capital equipment of the probe  10 , a preferred aspect of the invention is that the sheath  12 , working element  18 , electrode  20 , and core member  24  are intended to be disposable after a single use, and therefore do not require sterilization after use and are not required to be formed of a stainless steel or other durable metallic material that would enable these components to be sterilized and reused. For example, the sheath  12 , working element  18 , and core member  24  can be formed of polymeric materials, including but not limited to plastics of the types commonly used for disposable surgical components, for example, plastics manufactured in an FDA/ISO Certified Facility with FDA marketing clearance. As such, the term “disposable” is used and defined herein to mean an article that is not adapted to be cleaned, sterilized, and reused for a medical procedure performed on a patient. If the sheath  12 , working element  18 , and core member  24  are formed of electrically dielectric polymeric materials, the conductors  21  of the electrode  20  may be routed through the sheath  12  without requiring electrical insulation. Optionally, the distal end  14  of the sheath  12 , including that portion of the sheath  12  that protrudes over the opening of the sheath passage  25 , may be formed of or coated with a material that offers a greater degree of erosion and heat resistance to the high RF current levels, a notable but nonlimiting example of which is a phenol-formaldehyde resin such as Bakelite. Though also intended to be disposable, preferred materials for the electrode  20  include tungsten and stainless steels, though other materials could be used. 
         [0021]    To facilitate use of the probe  10 , the sheath  12 , working element  18 , electrode  20 , core member  24 , and telescope  34  of the probe  10  are preferably separable, allowing the electrode  20  to be removed from the core member  24 , allowing the core member  24  to be removed from the sheath  12 , and allowing the sheath  12 , core member  24  and telescope  34  to be separated from the working element  18 . The conductors  21  for the electrode  20  can be permanently fixed within the core member  24  or within the working element  18 , in which case the electrode  20  can preferably be electrically coupled and decoupled from the conductors  21  and/or the conductors  21  can preferably be electrically coupled and decoupled from the working element  18  with suitable quick-connect features. 
         [0022]    In view of the above, with the possible exception of the telescope  34 , all of the components of the probe  10  depicted in  FIGS. 1 through 5  are intended to be disposable. Due to being disposable, the electrosurgical probe  10  can reduce if not eliminate the handling, sterilization, packaging, and testing of and risk of damage to individual reusable components of probes that are currently used in electrosurgical procedures at surgery centers and hospitals. The risk of injury and/or contamination to the personnel involved with this process can be virtually eliminated with the disposable electrosurgical probe  10 . The electrosurgical probe  10  is not required to be re-sterilized after use, as is conventional with reusable electrosurgical probes, though it should be understood that each individual disposable electrosurgical probe  10  would be pre-sterilized prior to use to ensure safety. Maintenance, wear due to use, and cross-contamination are also avoided with the disposable electrosurgical probe  10 . Furthermore, it is foreseeable that the disposable electrosurgical probe  10  may be readily adapted or adaptable to particular brands of generators and telescopes. 
         [0023]    The electrosurgical probe  10  and its components shown in  FIGS. 1 through 5 , as well as other optional components and materials, can be packaged together to form what will be referred to as a “disposable electrosurgical kit” or simply a “kit.” The convenience and ability to access one kit with all the necessary components in a ready-to-use sterile package reduce the time and frustration that can be encountered when attempting to ensure that an electrosurgical probe and its components are available and ready to perform an electrosurgical procedure. Other major advantages include the ability to customize an individual kit, for example, to provide electrodes of various configurations within a single kit. In addition, the kit can offer different types of tubing connections to provide secure attachment to a scope, including but not limited to a stopcock, tubing with stopcock, and/or a luer connector. 
         [0024]    The disposable electrosurgical kit has the ability to save money, reduce procedure time, reduce the risk of hospital-acquired infections by patients, and reduce the risk of injury or infections to hospital personnel and physicians. The functionality of the disposable electrosurgical probe  10  and kit relative to conventional reusable electrosurgical probes is not affected by its disposable nature, as RF generators, light sources, and telescopes usable with the probe  10  can be the same as those commercially available and commonly used at surgery centers and hospitals. As such, physicians may maintain the power and optical equipment they are familiar with. 
         [0025]    While the invention has been described in terms of specific embodiments, it is apparent that other forms could be adopted by one skilled in the art. For example, the physical configuration of the disposable electrosurgical probe  10  could differ from that shown, a disposable telescope could be used, and materials and processes other than those noted could be used. Therefore, the scope of the invention is to be limited only by the following claims.