Microwave tissue dissection and coagulation

0001background 1. Technical field The present disclosure relates to systems and methods for providing energy to biological tissue, more specifically to electrosurgical instruments adapted to coagulate target tissue at the same time as an anatomical procedure.

00022. Background of related technology Energy-based tissue therapy is well known in the art. Various types of energy (eg, electricity, ultrasound, microwaves, cryogenics, heat, lasers, etc.) are applied to the tissue to achieve the desired result. Electrosurgery involves the application of high radio frequency currents to the surgical site where the tissue is cut, cauterized, coagulated, or sealed. In tissue ablation electrosurgery, radio frequency energy can be delivered to the target tissue by antenna or probe.

0003There are several types of microwave antenna assemblies used, such as unipolar, bipolar, and helical, which can be used in tissue ablation applications. In unipolar and bipolar antenna assemblies, microwave energy generally radiates vertically off the axis of the conductor. Unipolar antenna assemblies typically include a single, extended conductor. A typical bipolar antenna assembly contains two elongated conductors, which are linearly aligned and positioned end-to-end with respect to the electrical insulators placed between them. The spiral antenna assembly includes a spiral conductor connected to a ground plane. The spiral antenna assembly has a normal mode (broadside) in which the field radiated by the spiral is maximum in the plane perpendicular to the spiral axis, and an axis mode (endfire) in which the maximum radiation is along the spiral axis. It can operate in several modes, including. Depending on the physical properties of the spiral antenna element, such as the diameter of the spiral, the spiral distance or distance between the spiral rings, and the position of the spiral associated with the probe assembly on which it is mounted, the spiral antenna assembly The entrainment can be determined at least partially.

0004A typical microwave antenna is made of a dielectric material such that it extends along the vertical axis of the probe and is surrounded by a dielectric material, and the outer conductor also extends along the axis of the probe. It has a long, thin inner conductor that is further surrounded by an outer conductor that surrounds it. In another variant of the probe that provides effective energy emission or heating, some or more of the outer conductors can be selectively removed. This type of structure is typically referred to as a "leakage waveguide" or "leakage coaxial" antenna. Another variant in the microwave probe involves having a tip formed in a uniform spiral pattern, such as a spiral, which provides the necessary configuration for effective radiation. This variant can be used to direct energy in a particular direction, eg, in a direction perpendicular to the axis, in the forward direction (ie, towards the distal end of the antenna), or a combination thereof. In the case of tissue ablation, a high radio frequency current in the range of about 300 MHz to about 10 GHz is applied to the target tissue site to create a cauterized volume, which may have a particular size and shape. Cauterization volume correlates with antenna design, antenna tuning, antenna impedance, and tissue impedance.

0005Certain surgical procedures require the use of cutting instruments, such as scalpels or scissors, to remove tumors and / or other necrotic lesions, which forces one or more blood vessels to be cut. May cause unwanted bleeding. Such bleeding, in turn, obscures the surgeon's view of the surgical site, and the surgeon may generally need to be more concerned about controlling the bleeding rather than the primary surgical purpose. This, in turn, can lead to increased surgical time and suboptimal surgical prognosis.

0006Overview The present disclosure is directed to surgical instruments that utilize microwave energy for simultaneous tissue coagulation and dissection. In one embodiment, the instrument is a handheld surgical instrument with a curved and extended mandrel. The distal end of the mandrel comprises a directional microwave radiation assembly with a blade adapted to dissect tissue. The proximal end of the mandrel may include a handle and one or more actuators, such as a push button adapted to initiate the delivery of coagulation energy. Cauterization energy is provided to the microwave aperture by a coaxial supply line located within the mandrel.

0007The microwave aperture may have a hemispherical shape, an elongated cup shape, a bivalve shell shape, a cylindrical shape, a rounded cylindrical shape, a radial shape, and / or various combinations thereof. The opening includes a metal shield in addition to the bottom surface, which remains unshielded to allow targeted delivery of microwave solidification energy to the tissue. The use of the blade allows the surgeon to perform the dissection with the blade while simultaneously coagulating the tissue so as to control or eliminate bleeding at the surgical site with the simultaneous application of coagulation energy. Used in this way, a surgical instrument according to one embodiment of the present disclosure can allow a physician to simultaneously and rapidly coagulate and dissect a highly perfused solid organ, such as the liver. In turn, surgery time can be reduced, risk factors can be reduced, recovery time can be shortened, and patient prognosis can be improved.

0008In one embodiment, the surgical instrument comprises a handle and a mandrel extending distally from the handle. The mandrel is located coaxially within the hypotube, a lumen coaxially located within the hypotube and extending beyond its distal end, and an inner conductor and the inner conductor. A coaxial supply line having an outer conductor coaxially arranged around the inner conductor, and a coolant tube coaxially arranged between the lumen and the coaxial supply line so as to form an inflow and outflow conduits. And, including. The instrument further includes an anatomical head assembly connected to the distal end of the mandrel. The anatomical head assembly comprises a dielectric nucleus having a substantially planar radiating surface and at least one non-radiating surface and a reflective coating disposed on the at least one non-radiating surface of the dielectric nuclei. And a blade extending from the radiating surface.

0009The present disclosure also covers surgical anatomy and coagulation systems. In one embodiment, the surgical dissection and coagulation system comprises a microwave coagulation energy source and a surgical instrument as described above adapted to be operably connected to the microwave coagulation energy source. To be equipped. The disclosed surgical anatomy and coagulation systems may include a coolant source, where the surgical instrument is adapted to operably connect to the coolant source.

0010Also disclosed are methods for simultaneous dissection and coagulation. The method comprises locating the anatomical head of the surgical instrument throughout the tissue, where the anatomical head is from a tissue contact surface configured to apply coagulation energy to the tissue and from the tissue contact surface. Includes protruding blades. The tissue contact surface is contacted with the target tissue to initiate the incision, coagulation energy is applied to the target tissue, and the dissecting head is pulled across the target tissue to continue the incision.

0011Brief description of drawings The above and other aspects, features, and advantages of the present disclosure will become more apparent in combination with the accompanying drawings in the light of the detailed description below.

0012<figref num="1">A chart of an embodiment of a coagulation and anatomical system according to an embodiment of the present disclosure is shown.</figref><figref num="2">A side view of an embodiment of an anatomical head according to an embodiment of the present disclosure is shown.</figref><figref num="3">The bottom view of one embodiment of the anatomical head according to one embodiment of the present disclosure is shown.</figref><figref num="4">A cut-out view of a side surface of an embodiment of an anatomical head according to an embodiment of the present disclosure is shown.</figref><figref num="5">A cut-out view of a side surface of an embodiment of a handle assembly according to an embodiment of the present disclosure is shown.</figref><figref num="6A">The coagulation and anatomical procedures performed to utilize the coagulation and anatomical system according to one embodiment of the present disclosure are shown.</figref><figref num="6B">The coagulation and anatomical procedures performed to utilize the coagulation and anatomical system according to one embodiment of the present disclosure are shown.</figref><figref num="6C">The coagulation and anatomical procedures performed to utilize the coagulation and anatomical system according to one embodiment of the present disclosure are shown.</figref>

0013Detailed description Specific embodiments of the present disclosure are described below with reference to the accompanying drawings, but the disclosed embodiments are merely examples of the present disclosure and can be embodied in various forms. Well-known functions or structures and repetitive matters are not described in detail to avoid obscuring the present disclosure with unnecessary or redundant details. Accordingly, the specific structural and functional details disclosed herein are not to be construed as limiting, but merely as the basis of the claims and facts to those skilled in the art. Above, it is to be construed as a representative basis for teaching the various uses of the present disclosure in any appropriately detailed structure. In the present description, as well as in the drawings, similarly referenced numbers represent elements that can perform the same, similar, or equivalent functions.

0014In the drawings and in subsequent descriptions, the term "proximal" shall still refer to the end of the instrument closer to the user, while the term "distal" refers to the end farther from the user. Shall refer to. In addition, as used herein, terms that refer to orientation, such as "top," "bottom," "top," "bottom," "left," "right," "clockwise," " "Counterclockwise", and the like, are used for illustration purposes with reference to the figures and features shown therein. The embodiments according to the present disclosure can be carried out in any orientation without limitation.

0015Electromagnetic energy is generally classified into radio waves, microwaves, infrared rays, visible light, ultraviolet rays, X-rays, and gamma rays by increasing the energy or decreasing the wavelength. As used herein, "microwave" is generally 300 MHz (MHz) (3 x 10).⁸Frequency / sec) to 300 GHz (GHz) (3 x 10)¹¹Refers to electromagnetic waves in the frequency range (frequency / second). As used herein, "cauterization" generally refers to any ablation procedure, such as microwave ablation, radio frequency (RF) ablation, or excision assisted by microwave ablation. As used herein, "transmission line" generally refers to any transmission medium that can be used to propagate a signal from one point to another.

0016Various embodiments of the present disclosure provide a directional reflector assembly for treating tissue and an electrosurgical instrument operably associated with it, and a method of directing electromagnetic radiation to a target volume of tissue. The embodiments can be implemented using electromagnetic radiation at microwave frequencies or at other frequencies. An electrosurgical system having an aperture assembly that includes a directional reflector assembly and an energy applicator associated with operability is to operate between about 300 MHz and about 10 GHz with a directional radiation pattern according to various embodiments. It is composed.

0017Various embodiments of the currently disclosed electrosurgical instruments, their directional reflector assemblies, and electrosurgical systems, including the same, are in microwave ablation and in surgery assisted by microwave ablation. Suitable for use in precoagulating tissue for excision. The various methods described below target microwave ablation and destruction and / or excision of the target tissue, but in order for the target tissue to prevent, for example, the conduction of electrical impulses within the heart tissue. Methods for directing electromagnetic radiation can be used, along with other therapies that are destroyed, injured, or dissected. In addition, the teachings of the present disclosure may apply to bipolar, unipolar, helical, or other suitable types of microwave antennas.

0018FIG. 1 shows a microwave anatomy and coagulation system 10 according to an embodiment of the present disclosure. The dissection and solidification system 10 includes a cauterizing instrument 12 that is operably connected to the connector 21 by a coaxial cable 15, which further operably connects the instrument 12 to the generator assembly 20. The appliance 12 is operably connected to the coolant source 18, for example, saline or deionized water, by a coolant supply pipe 14 that is connected to the coolant source 18 by a fluid coupler 19. The coolant exits the appliance 12 via the coolant discharge pipe 13 which is connected to the coolant return container 16 by the fluid coupler 17. Fluid couplers 17 and 19 may include any suitable fluid coupler, including luer lock couplers without limitation. Coolant from coolant return 16 after cooling used coolant for subsequent reuse (eg, after cooling with heat exchangers, radiators, refrigerating equipment, Peltier modules, and the like) It can be recirculated to supply 18 or simply discarded after use. A fluid flow velocity can also be monitored by a flow velocity detector (not specified).

0019The generator assembly 20 can be a source of cauterizing energy, eg, microwave or RF energy in the range of about 915 MHz to about 25.0 GHz. In various embodiments, the generator 20 operates at 915MHz, 2450MHz, and / or 5800Mhz. Instrument 12 is adapted for use in various surgical procedures, specifically in anatomical and coagulation procedures. Instrument 12 includes a handle assembly 30 connected to the proximal end of the mandrel 40 and an anatomical head 50 connected to the distal end of the mandrel 40. The dissecting head 50 is configured to allow simultaneous tissue dissection and coagulation, as described in more detail below. Instrument 12 can be used in minimally invasive (eg, laparoscopic) or open surgical procedures.

0020FIG. 2-4 further illustrates the details of one embodiment of the mandrel 40 and the dissected head 50 according to the present disclosure. The mandrel 40 includes an external hypotube 60 formed from a heat resistant material that is substantially rigid. In some embodiments, the hypotube 60 can be made of stainless steel. In the illustrated embodiment, the mandrel 40 has a generally curved contour that positions the handle 30 and the anatomical head 50 in an ergonomically favorable orientation that facilitates their use in the surgical procedure. The mounting flange 73 is connected to the distal end of the hypotube 60 and is adapted to connect the hypotube 60 to the dissecting head 50. In some embodiments, the flange 73 is secured to the dissecting head 50 by a fastener 66, which can be a screw-in fastener (eg, a screw). The flange 73 can be fixed to the hypotube or the flange 73 and the hypotube 60 can be integrally formed by any suitable method including brazing, welding, screw fastening without limitation. In another envisioned embodiment, the hypotube 60 can be connected to the dissecting head 50 by any suitable method, including adhesive, overmolding, or integral formation.

0021The mandrel 40 is adapted to deliver electrosurgical energy and coolant to the dissecting head 50 and remove the coolant from the dissecting head 50, with several concentrically arranged elements within it. Including. As described in detail below, electrosurgical (eg, microwave) energy is delivered by coaxial supply line 55 and coolant is removed via the fluid outflow conduit 75.

0022The lumen 71 is located within the hypotube 60 and extends beyond the distal end of the hypotube 60 to the dielectric region 67 of the dissecting head 50. The lumen 71 can be formed from a thermosetting polymer such as polyimide without limitation. The mandrel 40 includes a coaxial supply line 55 arranged along its vertical axis. The coaxial supply line 55 includes an inner conductor 78 coaxially arranged within an outer conductor having an insulator 64 arranged between them. The coolant pipe 70 is concentrically arranged between the lumen 71 and the supply line 55 and divides the volume between them into a fluid inflow conduit 74 and a fluid outflow conduit 75. At their respective distal ends, the inflow and outflow conduits 75 fluidly communicate with the cooling chamber 76 defined within the distal region of lumen 71 within the anatomical head 50. During use, the coolant circulates distally through the inflow conduit 74, flows into the coolant chamber 76, and drains proximally through the outflow conduit 75.

0023The balun dielectric 63 is concentrically arranged around the supply line 55. In one embodiment, the balun dielectric 63 is located within the lumen 71 at or near the distal end of the hypotube 60 and the proximal end of the dissecting head 50. Any suitable heat resistant material with low electrical conductivity, eg, without limitation, polytetrafluoroethylene (EI in Wilmington, Delaware, USA) The balun dielectric 63 can be formed from PTFE or (also known as Teflon®) manufactured by du Pont de Nemours and Co. The balun outer conductor 61 is concentrically arranged around the balun dielectric 63. In some embodiments, the distal portion 56 of the balun dielectric 63 extends distally beyond the distal end of the balun outer conductor 61. The balun outer conductor 61 can be formed from any suitable electrically conductive material, such as rolled copper foil, copper tubing, and the like. In some embodiments, Polyflon, Norwalk, Connecticut, United States The balun outer conductor 61 can be formed from Polyflon electroplated PTFE, which is distributed by the Company. The balun dielectric 63 and the balun outer conductor 61 form a quarter wavelength short-circuit balun, below the tissue contact radiation surface 77 of the dissecting head 50 and / or within the reflective outer layer 69 of the dissecting head 50. Arranged to contain the radiated microwave energy to the region. Near the distal end of the coaxial feed line 55, the inner conductor 78 and the insulator 64 extend beyond the outer conductor 62. The inner conductor 78 extends beyond the distal end of the insulator 64 and is operably coupled to the distal radiating portion 65. The exposed portion 57 of the insulator 64, located close to the proximal of the distal radiating portion 65, serves as a supply point and / or a supply gap to it.

0024As shown in FIGS. 2, 3, and 4, the dissecting head 50 has a solid dielectric region having a reflective outer layer 69 located on its upper portion, eg, its apex and all sides. Includes 67. Dielectric region 67 includes a bottom radiating surface 77 that is generally flat and exposed. Unlimited pottery materials, PTFE, Teflon®, or Ultem amorphous thermoplastic polyetherimide (PEI) resin distributed by SABIC Innovative Plastics in Pittsfield, Massachusetts, United States. The dielectric region 67 can be formed from any suitable dielectric material having low loss dielectric loading properties, including sufficient mechanical and biocompatible properties to withstand the conditions associated with the surgical procedure. Without limitation, the reflective outer layer 69 can be formed from any suitable material capable of reflecting microwave energy, such as copper plated, copper foil, or PTFE electroplated with Polyflon . ..

0025As shown, the anatomical head 50 has an approximately wedge-like shape, but the anatomical head is unlimited, approximately hemispherical, generally elongated hemispherical, approximately bivalve, approximately truncated, approximately cylindrical. It is envisioned that it may have any suitable shape and portion that facilitates dissection and coagulation, including shape, approximately semi-cylindrical, approximately conical, approximately disk, and approximately truncated cone shapes.

0026The dissecting head 50 also includes a blade 68 extending downward from the bottom radial surface 77 and oriented substantially aligned with the vertical axis of the instrument 12. As shown, the blade 68 has a cutting edge 68a configured to cut tissue as the instrument 12 is pulled proximally, but the blade 68 and / or the cutting edge 68a in the other direction. It is envisioned that the instrument 12 can be arranged distally, laterally (left or right), or to cut tissue when pulled at any angle between them. To. In some embodiments, the blade 68 is movable. For example, and without limitation, the blade 68 may be rotatable around its vertical axis and / or the blade 68 may be retractable.

0027The dissecting head 50 is, without limitation, heat-resistant and biocompatible, such as polytetrafluoroethylene, polyethylene terephthalate, and parylene coatings, and tissues and other living organisms from which it adheres to the dissecting head 50. A lubricating coating (not specified) may be included on multiple portions of the reflective outer layer 69 and / or low-emission surface 77, which can be formed from any suitable lubricating material that reduces the potential of the material. ..

0028Looking now at FIG. 5, the handle assembly 30 has any suitable mounting method, such as welding (laser, sonic, chemical, etc.), adhesives, mechanical fasteners, clips, screw-in fasteners. , And a housing 80 that can be assembled from a two-piece (left and right half) double shell assembly, joined along a common edge by the same. The proximal end of the mandrel 40 and its associated internal components connect the mandrel 40 to the housing 80 and the mandrel 40 and dissecting head to the generator 20, coolant supply 18, and coolant return 16. It extends to the distal end 91 of the housing 80 to facilitate electrical and fluid connection of the portion 50.

0029The coolant multi-tube 81 is arranged in the housing 80, and the coolant multi-tube 81 has an inflow plenum 96 that fluidly communicates with the inflow conduit 74 and an outflow plenum that fluidly communicates with the outflow conduit 75. Has 97 and. The inflow port 98 is in fluid communication with the inflow plenum 96 to facilitate circulation of the coolant from the cooling source 18 through the appliance 12. Similarly, the outlet 99 fluidly communicates with the outflow plenum 97 to facilitate the discharge of coolant from the appliance 12. The proximal end of lumen 70 may include a photophore 82 to enhance the flow of coolant to the inflow conduit 74.

0030The housing 80 includes a 90 ° coaxial coupler assembly 100 configured to operably receive the coaxial cable 15 and electrically connect to the coaxial supply line 55. The coupler assembly 100 includes an outer conductor shift 94 configured to engage the outer conductor 84 of the coaxial cable 15 and an inner conductor shift 95 configured to engage the inner conductor 85 of the coaxial cable 15. ,including. The internal conductor shift 95 may include a female receiver 86 sized to receive the internal conductor 85 of the coaxial cable 15. The insulating regions 87 and 92 provide electrical separation between the outer conductor dislocations 94 and the inner conductor dislocations 95 and can be formed from voids or solid dielectric materials such as pottery or polymeric materials. When the insulating regions 87 and 92 are formed from a solid dielectric material, the insulating regions 87 and 92 can provide physical support for the outer conductor dislocations 94 and the inner conductor dislocations 95.

0031As shown in FIG. 5, a pair of elastomer O-rings 89 provide a fluid seal between the coupler assembly 100 and the inflow plenum 96, and between the mandrel 40 and the outflow plenum 97. In some embodiments, the coupler assembly 100 and inflow plenum 96, and mandrel 40 and outflow plenum 97 are glued composite (eg, silicone or epoxy encapsulant), compression fittings, screwed fittings, or optional. Each can be sealed by other suitable forms of fluid sealing. The housing 80 also includes a plurality of mechanical fasteners 93a-93f configured to engage and secure the aforementioned components of the handle 30 within the housing 80.

00326A-C show a method of performing tissue dissection and coagulation utilizing a microwave dissection and coagulation system according to an embodiment of the present disclosure. The illustrated example can be performed as an open surgical procedure or using minimally invasive (eg, laparoscopic) techniques. As seen in FIG. 6A, the anatomical head 50 of instrument 12 is positioned throughout the target tissue "T" so that the blade 68 is adjacent to the starting point of the desired incision. It should be noted that the curved shape of the mandrel 40 allows the surgeon's hand (not explicitly stated) to be advantageously positioned well above the desired cut surface while gripping the handle 30. The tissue contact radiation surface 77 of the dissecting head 50 is then contacted with the tissue "T", thereby penetrating the tissue "T" with the blade 68 to initiate the incision.

0033Upon contacting the tissue contact radiation surface 77 of the dissecting head 50 with the tissue "T", the surgeon activates the generator 20 to initiate the delivery of coagulation energy to the tissue at the surgical site. The activation of the generator 20 can also allow the coolant to flow through the appliance 12 through the inflow and outflow structures described above. Simultaneously with the delivery of coagulation energy to the tissue, the surgeon creates an incision "I" by pulling the dissecting head 50 proximally across the tissue "T". When the incision is formed, the coagulation energy radiated from the dissecting head 50 coagulates the tissue "T" within the coagulation region, generally indicated by the reference letter "C".

0034In one embodiment of the disclosed method, dissection and coagulation is performed by moving the dissecting head at a rate of about 3.5 mm / sec, which is a coagulation area with a width of about 1 cm and a depth of about 1 cm. Can be provided.

0035The size of the coagulation region "C" (eg, width and / or depth), either individually or in combination, can be determined by one or more of the multiple treatment parameters. For example, and without limitation, the size of the coagulation region "C" can be determined by the shape of the dissecting head 50. Instruments can be provided to the surgeon in a variety of shapes and scales that will allow the surgeon to select the size of the desired coagulation region "C" according to the surgical purpose. Coagulation scale by the power level of the delivered coagulation energy, the frequency of the delivered coagulation energy, the modulation of the delivered coagulation energy, and / or the speed at which the surgeon moves the dissecting head to create an incision "I". Can also be determined.

0036When the desired incision "I" is created, the surgeon shuts down the generator and coolant flow and pulls the dissecting head 50 out of the surgical site as depicted in Figure 6C.

0037The embodiments described in this disclosure are intended to be exemplary rather than restrictive, and are not intended to represent all embodiments of the present disclosure. The steps of the methods provided herein can be performed in combination and / or in a procedure different from that presented herein, without departing from the scope and spirit of the present disclosure. I want you to understand. Further modifications of the embodiments and other features and functions disclosed above, or alternatives thereof, are specified in the claims, both literally and in legal equivalents. As such, many other different systems or applications can be made or optionally combined without departing from the spirit and scope of the present disclosure.