MXPA99008190A - Electrothermal device for sealing and joining or cutting tissue - Google Patents

Abstract

A device and method are provided for sealing and joining or cutting tissue, which is particularly suitable for laparoscopic and endoscopic surgery. The device makes use of the controlled application of a combination of heat and pressure to seal adjacent tissues, to join adjacent tissues, or to anastomose tissues, whereby tissue is heated for an optimal time and at an optimal temperature under optimal pressure to maximize tissue seal strength while minimizing collateral tissue damage. The device of the present invention is lightweight and therefore portable, and is particularly useful in field conditions where a source of external power may not be readily available.

Description

ELECTROTHERAL DEVICE FOR SEALING AND JOINING OR CUTTING TISSUE FIELD OF THE INVENTION The present invention relates in general to a device and method for sealing and joining or cutting tissue. The device of the present invention is intended especially for use during either conventional open surgery or endoscopic or laparoscopic surgery.

BACKGROUND OF THE INVENTION Hemostasis, or blood coagulation, can be obtained by activating a biological pathway that is naturally known as the coagulation cascade. The path can be activated by tissue injury. This injury can come from mechanical, chemical or thermal sources. This natural biological path results in the conversion of freely flowing blood into a blood clot. Several biological elements are involved in the coagulation cascade, including tissue proteins, mainly fibrin and thrombin. Cells such as platelets and red and white blood cells are also involved. During surgery, hemostasis can also be achieved by direct denaturing of the proteins found in the blood. The denaturation of the protein means that its characteristic three-dimensional structure is altered without actually disintegrating the protein. This direct denaturation is a purely physical-chemical process in which the denatured proteins unite with each other, forming an amorphous mass of protein, which is comparable to a clot that occurs naturally. - How does the denaturation of a protein cause it to stick with neighboring proteins? proteins generally have a complex three-dimensional structure. A protein is actually a chain of smaller molecules called peptides, these peptides can have side chains that contain a molecular group that can attract a molecular group in another side chain. The main protein chain is cycled and folded on itself in a complex manner which results in the characteristic three-dimensional structure of the protein. This cycling and bending occurs due to an intramolecular attraction between the side chains of the peptides. This attraction between the side chains is usually the "hydrogen bond" or the electrostatic type. The attraction that holds the peptides together along the main chain is a covalent bond. When a protein is denatured, it loses its normal three-dimensional structure. As a result of this splitting of the protein molecule, the side chains in the peptides, instead of < being "in" to bend the protein chain are now able to bind to the side chains of proteins that are neighboring. This intermolecular bond results in the formation of a denatured protein lump. This process does not depend on the activation of the biological cascades of the natural coagulation mechanism, but is a purely physical-chemical process. For hemostasis, the tissue proteins that must be denatured are mainly those of blood such as hemoglobin and albumin but also include structural proteins such as those found in the wall of blood vessels or in other anatomical structures. One of the best ways to denature a protein is to heat it to a high enough temperature, to cause the intramolecular hydrogen bonds to break down, but not be so high to break the much stronger covalent peptide-peptide bonds throughout. the main chain. A common example of this process is the heating of an egg white until it turns white. This white color means that the original clear protein has been denatured. ' The heating that is administered to the proteins of the tissue can begin as electrical energy, as light energy, as radio energy or as mechanical energy (vibratory or friction). As for the tissue, it does not matter whether dual is the original source of energy, as long as it becomes heat in some way. For example, if the energy source is a laser, then the light energy is absorbed by molecules in the tissue whose absorption spectrum matches the wavelength of the laser light that is being used. As soon as the light energy is absorbed, heat is produced, and the physical-chemical process of the denaturation of the protein is achieved. Any kind of light energy will have this effect, if its wavelength is such that it can be absorbed by the tissue. This general process is known as photocoagulation. The advantage of using a laser is that, since its output is monochromatic, certain tissue elements that have the correct absorption spectrum can be selectively heated, while leaving the other tissue elements for which the laser light is left. It is not absorbed. This principle is commonly used in ophthalmology. Another advantage of using a laser is that its ray coherent and collinear? you can focus very precisely on very small objectives. If spatial precision or selective photocoagulation of only certain tissue elements is not important, then it is perfectly possible to coagulate tissue using a very bright but otherwise ordinary light. If the energy source is electrical currents flowing through the tissue, the process is called "electrosurgery". What happens here is that the current flowing through the fabric heats the fabric because the fabric has resistance to the flow of electricity ("ohmic heating"). In the case of ultrasonic coagulation, the rapid vibration of the ultrasonic element induces the heating essentially in the same way as the production of fire by rubbing sticks together (although the speed of the vibration is much higher and the process is more controllable). Since it is heat that denatures and coagulates proteins, why take the trouble to start with a laser or an electrosurgery unit? Why not use a very simple source of heat, such as a resistance wire or, even simpler, a piece of hot metal? In ancient times, "cauterize" via a hot piece of iron was used to staunch wounds with hemorrhage. The problem with "this approach is not" ficacy, it is the control and containment of the amount and degree of tissue that is cauterized or injured. In fact, the development of "electrocautery" in the late 1920s by physics professor William T. Bovie was spurred by the desire (pioneering neurosurgeon Dr. Harvey Cushing) to make a more controllable and refined medium to produce heat in tissues that possibly using a large piece of metal. Electrocautery uses very high frequency alternating current, since it has been found that these high frequencies do not cause tetanic ("galvanic") stimulation of muscle tissue, which occurs when direct current or a low frequency current is used. To avoid muscle stimulation, it is necessary to use alternating currents with very high frequencies, of approximately several hundred thousand cycles per second. This high frequency falls within the range of the modulated amplitude radio band, this is the reason why many electrical devices such as monitors used in the OR will register interference when electrocautery is activated. There are many potential problems that arise from the use of these high frequencies, which include the difficulty of controlling transient currents that can harm patients and interfere with pacemakers and computer equipment. Electrocautery has been refined over the last 50 years, but it still represents a way of rodeo to get the tissue to heat up. Numerous coagulating devices are known, seal, join, or cut tissue. For example, there are electrosurgical devices, both monopolar and bipolar, that use high frequency electrical current that passes through the tissue to be coagulated. The current that passes through the tissue causes the tissue to heat up, resulting in the coagulation of tissue proteins. In the monopolar variety of these devices, the current leaves the electrode and after passing through the tissue, it returns to the generator by means of a "ground plate" which is attached or connected to a distant part of the patient's body. In a bipolar version of this electrosurgical device, the electric current passes between two electrodes with the tissue placed or held between two electrodes as in the "Kleppinger bipolar forceps" used for the occlusion of the fallopian tubes. There are many examples of these monopolar and bipolar devices commercially available today in companies that include Valley Lab, Cabot, Meditron, Wolf, Storz and others all over the world. A new development in this area is the "Tripolar" device marketed by Cabot and Circon-ACMI which incorporates a mechanical cutting element in addition to the monopolar coagulation electrodes. With respect to the known ultrasonic devices, a very high frequency (ultrasonic) vibratory element or rod is held in contact with the tissue. These rapid vibrations cause the proteins in the tissue to coagulate. The ultrasonic device also employs a means to grasp the tissue while the proteins are being coagulated. Olympus sells a heating probe device which uses an electric heating wire contained in a flexible catheter-type probe that is used to be passed through a flexible endoscope. It is used to coagulate small vessels with hemorrhage found inside the gastrointestinal tract or vessels with hemprhagia found in peptic ulcers or other gastrointestinal classes. In this device, no electric current passes through the tissues, as is the case with monopolar or bipolar cauterization. This device would certainly not be suitable for use in laparoscopic surgery or in open surgery in which large amounts of tissue should only coagulate but also be divided. There are several known patents: Pignolet, U.S. Patent No. 702,472, discloses a jaw-tissue forceps with jaws wherein one has a resistance to heat the jaw, and a battery to energize the heater. The coagulated tissue caused by heat and pressure subsequently divides along the edges of the jaws after they open.; Downes, U.S. Patent No. 728,883, teaches an electrothermal instrument having opposing members of jaws and handle members to activate the jaws. The resistance member is installed on the jaw member which is closed to have direct contact by a plate. This device coagulates the tissue by heat, not by electric current, applied to the tissue; Naylor, U.S. Patent No. 3,613,682, discloses a disposable battery-powered cauterization device, - Hiltebrandt et al., US Pat. No. 4,031,898, refers to a coagulator with jaw members, one of the which contains a resistance coil. This device has a timing mechanism to control the heating element. The heating element is used directly as a temperature sensor; Harris, U.S. Patent No. 4,196,734, shows a device that can perform both electrosurgery and cauterization. A thermistor temperature sensor element monitors a heating cycle and regulates the current and by this the temperature; Staub, U.S. Patent No. 4,359,052, relates to a cauterization device with removable cauterization heating tip, energized with batteries; Huffman, United States Patent of North American number 5,276,306, discloses a portable heating device that is gripped as a gun having a firing mechanism for the battery, - Anderson, U.S. Patent No. 5,336,221, shows an optical thermal clamping device for welding or melting tissue , and that employs a cutting knife to separate the melted tissue; Stern et al., U.S. Patent No. 5,443,463, discloses clamping jaw members bifurcating by a cutting blade, having plural electrodes and temperature sensors, and can function as monopolar or bipolar; and Rydell, et al., U.S. Patent No. 5,445,638, refers to a bipolar coagulation and cutting instrument. Although each of the aforementioned references is relevant to the invention herein, neither shows nor suggests the entirety of the invention taught and claimed herein. OBJECTS OF THE INVENTION It is an object of the present invention to provide a device for sealing and cutting tissue. It is also an object of the present invention to provide a device for sealing and joining tissue. It is another object of the present invention to provide a portable device that does not require an external power source. It is another object of the present invention to provide a device that can be constructed to conform to the requirements of laparoscopic and endoscopic surgery, i.e., that it be long and very thin, in the range of a few millimeters in diameter or even narrower. It is still another object of the present invention to provide a method for performing surgical procedures using the device of the present invention. It is still another object of the invention to provide a method and apparatus for optimal heating and optimum pressure to optimize the sealing strength of the fabric and to minimize collateral damage to the fabric. These and other objects of the invention will be apparent to those skilled in the art from the following more detailed description of the invention.

COMPENDIUM OF THE INVENTION According to the invention, there are three parameters that are controlled independently - the temperature at which the fabric is heated, the pressure applied, and the time during which the temperature and pressure are maintained. The total heat applied to the tissue is a function of temperature and time. A key feature is the combined (simultaneous, partially simultaneous, or sequential) application of pressure and heat to the tissue that is being coagulated for a specific amount of time, which induces the denatured proteins to stick together, which at it helps to achieve hemostasis with less heat energy than would be required without pressure. Also, the total energy applied is minimized by means of the configuration and materials of the parts of the device that keep the tissue in opposition during the application of heat and pressure. Using less heat energy means less collateral damage. further, results that are at least as good as could be achieved with electrosurgical and ultrasonic tissue coagulation units, but with a much smaller, lighter energy source, such as a battery, can be achieved. Also, a method of heating the tissue is very simple and direct. Since the basic heating element is so simple, improved results can be achieved at a fraction of the cost of the closest tissue heating means. In accordance with one aspect of the present invention there is provided a device and method for sealing, or coagulating, and cutting tissue during surgery. The device incorporates means to controllably heat the tissue while simultaneously applying a defined and controllable amount of pressure to the tissue being heated. Due to the combined application of heat and pressure, the tissue proteins will coagulate and the blood vessels within the tissue will be sealed, achieving hemostasis. Optimal sealing or tissue coagulation means producing a strong and durable seal or coagulation or anastomosis with a minimal amount of collateral tissue damage. In the device of the invention optimization is achieved by a combination of the physical configuration of the part of the device that holds the tissue during the coagulation process and regulation of time, temperature and pressure. As part of the control, the heat can be applied in impulses instead of a continuous way. The application of pulse heat allows the tissue that is adjacent to the coagulation time area to recover from the heating process and to remain viable. Also, the application of the pressure can be variable in intensity and can also be applied in a pulsed or discontinuous manner. It is an aspect of the present invention to provide a method and device for the surgical treatment of biological tissue, wherein thermal energy and pressure are applied simultaneously, substantially simultaneously, consecutively, or alternatively, for a time such that the proteins of the tissue are denaturated. and that the tissue adheres either to itself or to other tissues, with the purpose of coagulating hemorrhages, sealing tissue, joining tissue and cutting tissue. The minimum amount of heat or thermal energy necessary to carry out these goals is spent, so that thermal damage to the tissue adjacent to the treated site is minimized. The device may also incorporate means for cutting, or separating, the tissue after the tissue has been coagulated, "cutting" includes tissue dissection or division, tissue disruption or separation, flat development, or definition or mobilization of the structures of the tissue. tissue in combination with coagulation or hemostasis or sealing of blood vessels or other tissue structures such as lymphatics or tissue junctions. The cut can be carried out by means of a knife which is passed through the coagulated tissue while the tissue is being held in the jaws of the device. The cut can also be achieved thermally by using amounts of heat greater than the amount required to coagulate the tissues. Alternatively, the cut can be achieved by other mechanical, ultrasonic, or electronic means, including, but not limited to, shear action, laser energy, and radiofrequency, or a combination of two or more of the foregoing. In the case of using thermal energy to achieve tissue cutting, the device and method will use the minimum amount required to divide tissue with the least amount of undesirable tissue necrosis.The heating element can be a resistance wire through The electric current is applied through the wire either as a direct current or as a series of pulses of defined duration and frequency, unlike conventional electrosurgical devices., the electrical current of the devices of the invention does not pass through the tissue, which can cause problems - due to transient electric currents. The electrical elements are electrically isolated from the tissue at the same time as they are in good thermal contact. In a simple device mode, the total amount of direct current and therefore the total heat energy applied to the tissue, is limited in duration by a simple timing circuit or even by direct visual inspection or other sensory inspection of the treated tissue . In a more sophisticated mode, the configuration and duration of the pulse train is under the control of a simple microcontroller, such as an integrated microprocessor. With the control of the microprocessor, a thermistor heat sensor is incorporated into the part of the device that grabs the tissue being coagulated. The microprocessor takes temperature readings from the thermistor and adjusts the configuration and duration of the pulse train to achieve the optimum temperature that "cauterizes or seals the tissue while minimizing unwanted collateral thermal damage." The actual value of the optimum temperature can be verified experimentally for this particular device, the temperature of the sealing treatment according to the invention is preferably maintained in the range required to denature tissue proteins (approximately 45 ° C to below 100 ° C) while avoiding excessive tissue necrosis. Maintaining the temperature in the range required to achieve denaturing of the protein without excessive tissue necrosis means that the total heat energy expended in the treatment has to be less than if the temperature did not stay in this range. heat spent in the treatment is related to the degree of heat (l at temperature) and the length of time during which the heat is applied. The combined application of pressure with heat reduces the amount of heat or the degree of temperature that would be required to make the denatured proteins actually stick together. This combined application of pressure also increases the strength with which the denatured proteins actually stick together, for a given amount of heat energy at a given temperature. The amount of applied pressure is regulated by springs or other elastic elements, or mechanically functional equivalents, which can result in the fabric being held with a predetermined amount of force per unit area, despite variations in size or thickness of the tissue that is being sealed or coagulating. The pressure can also be regulated by mechanical elements or separators or by the geometry of the elements that produce pressure. As with the temperature value, the exact values for the pressure to be applied can be verified for this device with proper measurement calibration. The controlled application of a combination of heat and pressure that is sufficient but not excessive to produce a durable coagulation or seal has the result that only a relatively small amount of heat energy is needed. That only a relatively small amount of heat is needed means that relatively small electric batteries can be used as the energy source to produce the heat. A device of the invention therefore may lack bulky and heavy external power generators such as those required with conventional electrosurgery, lasers or other devices for coagulating tissue. Because small batteries can be used to energize the device, the device can be made quite compact and lightweight, as well as portable * and / or disposable. The use of batteries or other low voltage direct current sources makes it easy to avoid the risks and inconveniences caused by electrical interference and transient currents, which are presented in conventional high frequency electrosurgical devices. The risks to the eyes by laser are also avoided by this. Since the heating elements and the pressure producing elements of the device can be inherently simple and inexpensive to be manufactured, the part of the device that comes into contact with the fabric can be made disposable, if desired, while that the most expensive portions of the device can be made reusable. If the device incorporates a simple timer, instead of the microprocessor-thermistor controller, the entire device including the batteries can be made very cheap and disposable. Different embodiments of this device employing the same general principle of controlled application of a combination of heat and pressure can be used to join or "weld" adjacent tissues to produce a tissue joint or an anastomosis for tubular tissues. Tissue binding is essentially a special case of the controlled coagulation of tissue proteins that achieve hemostasis. It is another aspect of the present invention that these effects will be spatially confined by the physical configuration and the materials employed in the construction of the device. The configurations and materials of construction are such that Jl) the tissue is kept in apposition with sufficient pressure to effect a strong binding of the denatured proteins but not enough pressure to cause tissue necrosis, (2) the heat is concentrated on the tissue which is being treated by means of the material of the jaws that support the tissue being treated, this material being a thermal insulator which prevents the heat from being spent heating adjacent tissues. This material can also employ a reflective or cover layer to again reflect heat energy to the treated tissue, which would otherwise be lost by thermal radiation. This material - may also have a geometry or be in a form such that it focuses thermal energy on the treated tissue away from the tissue it does not intend to treat. For example, the jaws of the device may have a "concave or parabolic inner surface for focusing thermal energy." It is another aspect of the present invention that these effects will be spatially confined according to the class, amount, and duration and temporal distribution. of the application of energy. The energy could originate as heat, light, sound or electricity, chemistry, or other forms of energy, as this energy is converted into heat to denature the proteins of the tissue. In a preferred embodiment, the energy would be delivered from a low cost, simple thermal heating element, which could be energized by a battery contained in the same device. The energy could be administered in a continuous manner, or in a driven or intermittent mode, at variable or constant intensity. Energized or intermittent administration of energy can produce a spatial confinement of the energy distribution. Feedback (including optical, thermal, spectroscopic, among others) and a microprocessor could be used to control the thermal effect. In the case of tissue coagulation, sealing or bonding, the temperatures produced by the energy source would be in the range of from about 45 ° C to about 100 ° C for a sufficiently long duration to produce the denaturation of the proteins in the tissue treaty. The source of heat or energy administration can be a simple wire that is electrically resistant, straight or curved, a grid or pattern of wires, or a thin film or coating of electrically resistant material. One or more energy elements can be used. They may target some or all of the tissue treated by the pressure elements. The energy management source can be integrated or separated from the pressure elements. Cutting elements can be incorporated into the energy elements. The energy or heat source can be moved or fixed. The energy can be administered in a similar or dissimilar plane compared to the direction of the application of pressure. The source of energy or heat can be constructed so that its shape and size can be varied to conform to different anatomical situations, shapes and thickness of tissue. For example, an inflatable balloon coated with an electrically resistant material could be used as the source of heat. Another example would be that the heat source could have a type of extendable fan configuration which could be enlarged ("extended fan") to cover a larger area or a smaller area as needed. Another example would be a flexible sheet-like configuration that could be wrapped around the tissue to be treated. It is another aspect of the present invention that these effects would be spatially confined according to the kind, amount, and duration or temporal distribution of the pressure administration acting together with the source of energy or heat. The administration of pressure will usually be from a minimum of two elements of the apparatus but in some cases it can be from a simple stop or by pressing a simple element against the tissue, as in the example of the circular cutting wheel or a biopsy device central. Any combination of geometric arrangement can be produced between the power source and the pressure source, including energy source - pressure and separate sources of energy and pressure. A constant requirement is that the energy element delivers energy to at least some of the tissue that is under pressure by the pressure element. The pressure element can also be variable in shape, being able to adjust its shape before or during the application of energy or pressure to adapt to different anatomical situations, shapes or thicknesses of tissue. The "cutting elements or other elements for shaping or forming the fabric can be incorporated with the pressing element, For example, the pressing element can be composed of a flat side with a sharp upward angle center to produce a combination of cutting effect on the center with compression along the sides The applied pressure can be constant or variable in time, and the relationship of the pressure elements with the fabric can be constant or variable during the application of the pressure and The movement of the pressure elements conveniently configured to carry out the cutting, before, during or after the application of the energy or pressure can be used.The variable application can also be controlled by feedback of pressure transducers or Transient sensors that act with a microprocessor It is an aspect of the invention that a complete cutting element can be used. separate you apart from the separate elements of energy and pressure. It is also an aspect of the invention that mechanical tissue fastening devices that include sutures, staples, locks, bands, screws, plates or tacks could be incorporated into the device. In this case the thermal energy and the pressure would be used to provide mainly the coagulation and the sealing and the mechanical elements would provide additional strength to the union of the tissue or anastomosis. The invention can be used in either open, laparoscopic, endoscopic surgery or any form of minimally invasive surgery. Surgical devices based on this invention could be long and thin, suitable for laparoscopic or minimally invasive approaches. The parameters of temperature, time, pressure, as well as any adjustable physical configuration or geometry of the device could vary depending on the type, size and thickness of the fabric being treated. These parameters can be determined experimentally before the actual treatment and incorporated into the device by means of a table of "consultation" in a microprocessor or by means of simple markings and calibrations of adjustable knobs, disks, etc. of the device. For the purpose of thermally joining or anastomosing two hollow tubular structures, ie, small blood vessels or vas deferens, a preferred embodiment would incorporate two cylindrical or circular elements. These cylindrical elements would be designed to fit one within the "otherd. , acting as a template or temporary vascular implant that would hold the two tubular structures together while the heat is applied. The tubular structures would be maintained in this manner to provide either a certain amount of overlap or end-to-end contact. As in the previous modalities, the amount of coadaptive pressure that is being applied would be optimized according to the type and thickness of the tissue. The heat would be provided by a heating element or elements incorporated in the cylindrical stencils or vascular implants and positioned to apply the heat to the parts of the two tubular structures that are in overlap or in end-to-end contact. As discussed above, the amounts of heat and pressure applied are the minimum required to produce a safe anastomosis with the least amount of collateral damage. Another modality of this device would employ a circular mechanical cutting element, convenient for obtaining "core" biopsies of solid organs such as the liver or a kidney. This circular, cylinder-shaped mechanical cutting element with sharp edges at one end would incorporate an electrically resistant element on the outside of the cylinder. This electrically resistant element could be in the form of a thin film of strength material. As the tissue was mechanically cut by rotating or pushing the cylindrical cutter into tissue, the cutter would create hemostasis along the track by the heating element outside the cutter. The cylindrical cutter would be constructed of a material, or would incorporate a layer of a material, so that the tissue core sample would be removed insulated from the thermal effects of the heating element on the outside of the core. This design would allow the removal of tissue samples that are not distorted by heat changes and would also allow for safe haemostasis along the biopsy tract. In this device the lateral pressure exerted by the cylinder wall in the track's tissues can not be explicitly controlled; however, there is a pressure, and this pressure is part of the achievement of hemostasis. In another embodiment of the invention, a circular cutting wheel would be mechanically rotated to cut tissue, such as skin. This circular cutting wheel would incorporate along its clamping ring, a thin electrically resistant film. This electrically resistant element would provide hemostasis as the rotating mechanical flywheel cuts the tissue. In yet another embodiment of the invention, an inflatable elastic balloon could be used to apply heat and pressure to the fabric. The outer surface of the balloon would be partially or completely covered with electrically flexible, optionally stretchable material that would be heated when an electric current was applied. Here, the pressure exerted on the tissue can be controlled by regulating the inflation pressure of the balloon. Another embodiment of this invention is an improvement in endoscopic "hot biopsy" forceps such as that used for colonoscopy. The standard "hot biopsy" forceps use conventional electrosurgical energy sources and unfortunately are associated with excessive cauterization of the tissue of the bowel wall that is outside the forceps jaws. Our modality of "hot biopsy" forceps would incorporate an electrically resistant element only in the interior aspect of the bite part ("tooth") of the forceps jaws. The rest of the forceps jaw "would be made of a material that would provide thermal insulation to the adjacent tissues, thus obtaining a biopsy specimen with good hemostasis and protected from inadvertently cauterizing the adjacent tissue outside the forceps, This could lead to a perforation, yet another embodiment of the invention would be a device type clamp, similar in physical appearance and mechanical function to the polypectomy traps used during colonoscopy, unlike conventional clamps, which use sources of monopolar electrosurgical energy, the clamp of this modality would use a wire or band specially configured with an electrically resistant material applied to the internal aspect of the wire or band for that portion of the wire or band that is used to make the actual loop that traps the tissue . This modality would tend to direct the thermal energy towards the substance of the tissue that is being grasped with the snare, as opposed to the conventional electrosurgical snares in which the electrical current can be specifed along the stem or through the base of a polyp and cause damage to the underlying bowel wall and even perforation. The device can be used in surgery and is particularly suitable for laparoscopic and endoscopic surgery. Because our method uses heat energy in the minimum amount and at the lowest temperature consistent with achieving denaturation and linking tissue proteins together, devices that work based on this method will be able to function more efficiently than surgical energy devices. conventional Therefore, these devices can be portable and even battery powered, which makes them ideal for portable or military applications. There is no device or method in the prior art that purposefully seeks to obtain surgical coagulation, sealing, joining or cutting by a combination of heat energy and pressure at a time, temperature and pressure which together are sufficient but not excessive to produce the denaturing of the proteine, and with a physical configuration and construction materials that promote the union of the tissues that are being treated while minimizing the losses of heat energy to the surrounding tissues beyond the treatment zone.

BRIEF DESCRIPTION OF THE DRAWINGS Reference is made to the following description taken in connection with the accompanying drawings, in which: Figure 1 is a schematic representation of one embodiment of the present invention; Figure IA is a cross section along the line II of the embodiment in Figure 1 with the jaw in the closed position, - Figure 2 is a top view, partly in cross section of the lower jaw of the embodiment of Figure 1 showing the heating and cutting elements; Figure 3 is a plan view of another embodiment of the invention; Figures 4 and 5 are "cross-sectional views of the embodiment of Figure 3; Figures 6 and 6A are a plan view and an enlarged partial view, respectively, of another embodiment of the invention; Figures 7 and 7A are a plan view of a partial cross-sectional view, respectively, of another embodiment of the invention, Figure 8 is a partially cross-sectional view of another embodiment of the invention, Figure 9 is a plan view of still another embodiment of the invention: Figure 10 is a top view, partly in cross section of the embodiment of Figure 9, and Figure 11 is a plan view of another embodiment of the invention for heating and cauterizing tissue.

DETAILED DESCRIPTION OF THE INVENTION The invention may perhaps be better appreciated from the drawings. Figure 1 presents a schematic representation of the device of the invention showing an upper jaw 10, a lower jaw 12, an elongated shaft 14 attached to a handle 18, having a lever 20 for opening and closing the jaws. The upper jaw 10 is attached to the articulation 11 with the spring support member 13, and the spring 15 is attached to both the upper jaw 10 and the spring support member 13 to deflect the upper jaw 10. The lever 20 operatively connects through the rod 21 to one or both of the upper jaw 10 and the lower jaw 12. The end of the arrow 14 closest to the handle 18 is provided with (1) a pusher 16 that is operatively connected through the member 17 and the connector 23 to a blade of cutting blade 19 housed in the lower jaw 12 and (2) a trigger 22 to activate the pusher 16 which in turn activates the cutting blade 19. The lower end of the handle 18 is provided with a rechargeable battery pack 24, which is operatively connected to the activator of the heating element 27 and to the heating wire element 26 in the lower jaw 12. In Figure IA, the tissue segment 25 is gripped between the jaws 10, 12, where it can be cut by the sheet 19. Figure 2 represents a top view of the lower jaw 12 showing the relative locations of the wire element heating 26 and a slit 28 for the cutting blade 19, inside the jaw 12. The heating wire element 26 is in a slit of a depth such that the wire substantially runs with the super of the jaw 12. Preferably the distal portion 29 of the heating wire element 26 is below or outside the plane of the heating wire element 26 so that only two parallel areas of the fabric will be sealed. The heating wire element 26, which preferably is composed of nichrome or another electrically resistant suitable metal or alloy, or an electrically resistant thin film or coating will preferably have a non-stick coating that is thermally conductive, convenient, electrically conductive. Examples would include polytetrafluoroethylene (PTFE), for example, TEFLON® or other non-stick coatings used for cooking. Moreover, one or both of the facing surfaces of the upper jaw 10 and the lower jaw 12 can optionally be corrugated, irregular, or fluted. _ Both the upper and lower jaw are composed of a material, such as ceramic, that is thermally insulating or thermally reflective. In this way, the heat generated by the heating element is confined to the space between the jaws, and is not allowed to spread or radiate to other fabrics that may be in contact with the outside of the jaws. This is beneficial in two ways: first, the heat generated by the 'heating element' is used efficiently to perform the sealing or the desired coagulation and second, the surrounding tissues are protected from inadvertent thermal damage. As will be appreciated by a person skilled in the art, the heating, pressure, and / or cutting functions could be synchronized mechanically, electromechanically, or electronically to obtain optimum results in accordance with the invention. Also, the device shown in Figures 1, ÍA and 2 optionally may not have a cutting element. This device would be used for situations where only heating and pressure would be necessary to join the tissue or to heat and cauterize tissue from another triode to produce coagulation.

In the embodiment of the invention shown in Figures 3 and 4, a cylindrical member 30 is concentrically positioned around a rod 32, the distal portion of which forms an anvil 23. The distal surface of the cylindrical member 30 comprises a heating element. circular 34 and a circular cutting element 35 positioned concentrically inside the heating element 34. The anvil 33 is configured so that when the rod 32 moves proximally, the proximal circular edge 36 of the anvil 33 cooperates with the heating element 34 for coagulate or seal the tissue. The use of the embodiment of Figures 3 and 4 can be seen in Figure 5, where, for example, two sections of intestine 38, 39 are placed to join together. Initially one end of each of the sections 38, 39 loosely connects with the ligatures 40, 41 around the rod 32. Then, the rod 32 moves distally to cause the circular edge 36 of the anvil 33 to force the portions of intestines 38, 39 in contact with the heating element 34. The intestine sections 38, 39 are joined to each other, and the excess tissue is cut by the cutting element 35. The rod 32 is pulled further in the proximal direction to removing the excess tissue, the cylindrical member 30, and the anvil 33. Further, the device shown in Figures 3 to 5 to produce circular anastomosis based on heat and pressure could additionally incorporate mechanical fastening elements such as staples. This device is shown in Figures 6 and 6A, wherein a circular stapler device 42 comprises a main arrow 43, - a handle 44, a staple housing 45, and an anvil 46. The anvil 46 is fixedly attached to the distal end of the date of the anvil 47 which slides movably within the housing of the staples 45, the main arrow 43, and the handle 44. The distal surface 48 of the staple housing 45 has slots 49 for staples (not shown) ) and an electrically resistant coating or member 50. An inner circular member 51 with a cutting edge 52 fits circumferentially around the arrow of the anvil 47, as can be seen more clearly in Figure 6A. Optionally, slots 49 and cover 50 could be coextensive. The handle 44 comprises means for operating the anvil 46 and the heating element 49 and for firing the staples. As will be appreciated by those skilled in the art, a lever or staple trigger member 53 may be operatively connected to a cylindrical thrust member within the staple housing 45 that causes the staples to be ejected from the slots 49. - The operation of the circular stapler device would be similar to that of the device shown in Figure 3, with the exception that staples would be fired on the tissue to be joined. Preferably the staples would fire after sealing and at the same time cutting. The staples would act together with the thermal energy to increase the strength of the tissue seal, bond or ligament at the same time that the thermal energy would increase the hemostatic capacity of the staples. Staples or other mechanical tissue fasteners could be used in conjunction with thermal energy sealing in configurations other than circular, such as linear or angular. Figure 7 depicts an embodiment of the invention that is essentially a tissue core removal device. The tissue core removal device 56 comprises a cylindrical member 58 having a proximally extending handle fixedly attached 60. The cylindrical member 58 comprises a sharp cutting edge 62 and a heating element 64 - accommodated on the surface outer 66 of the cylindrical member 58. Consistent with the above description, a tissue sample is obtained by inserting the removal device 56 into an organ, the device 56 being rotated as it moves forward. The rotation could be either clockwise or counterclockwise, but preferably alternating directions, with sufficient pressure to cause edge 62 to cut. The heating element 64 will cauterize or seal the tissue adjacent to the tissue sample to be removed, and when a tissue sample of sufficient depth is placed inside the cylinder 58, the device 56 will be removed. As is conventionally done, the removal device 56 would preferably contain means for removing a tissue sample, such as an internal piston 59 having a proximally extending trigger 60 to force the sample to be expelled from the distal end of the device. removal 56. As would be appreciated by those skilled in the art, a tissue core removal device could optionally have additional cutting means at its distal end to assist in the separation of the nuclear tissue sample from the tissue mass. In Figure 8 the distal portion 70 of an electrothermal biopsy needle comprises a circumferentially slidable outer sheath 72 accommodated around a slotted internal style 74 having a slot 76 for capturing a tissue sample 78. The outer sheath 72 has a cutting edge 73 separating the tissue sample 78 from the remainder of the tissue mass (not shown) and enclosing the sample 78 in the slot 76 when the outer sheath 72 is driven distally by the activator (not shown). The outer sheath 72 preferably has an electrically resistant film 75 covering its distal portion. The film 75 may have separate electrical contacts or connectors 77. In another embodiment of a biopsy needle where the stylet 74 has an internal cutting member (not shown), the stylet or the internal cutting member, or both, may have an electrically resistant coating or film. The aforementioned aspect of the invention could be incorporated into known biopsy devices. See, for example, U.S. Patent Nos. 4,600,014 and 5,595,185, both incorporated herein by reference with respect to their descriptions of biopsy devices. Figures 9 and 10 represent a circular cutting mode of the invention in which a disc 80 having a sharp outer edge 82 is joined at its center to a rod 84 which is rotatably secured to the forks 86 of the handle 88 The adjacent edge 82 is a circular heating element 90, which may be on one or both surfaces of the disk 80. Each heating element 90 is electrically connected to the fork 86, for example, through one or more brushes 91. Figure 11 depicts an embodiment of the invention wherein a heating and cauterization device 92 comprises a catheter 94 and an inflatable balloon 96 sealably attached to the distal end of the catheter 94. The catheter 94 comprises at least one lumen 98, the which is in fluid communication with the balloon 96 to inflate and deflate. The proximal end of the catheter 94 is in fluid communication with a regulated pressure source or inflation source (not shown) for inflating and deflating the balloon 96. The balloon 96 has an electrically resistant film coating 100, at least two portions separated from which are connected with wires 102 that "extend proximally along or within the catheter 94 to an energy source 104. The electrically resisting film 100 is intended to cover a substantial portion, if not all, of the outer surface of the balloon 96. In use, the device 92 with a deflated balloon 96 is manipulated inside. of the body of a patient, for example, intracorporeally or even percutaneously, to place the balloon 96 adjacent to a site to be cauterized. Then, the balloon 96 is inflated so that the electrically resistant film coating 100 contacts the area to be cauterized, after which the film coating 100 is energized with electrical power from the source 104. After If the heat and pressure produce the desired effect, the energy goes out and the balloon deflates to facilitate its removal. - - With respect to the embodiments of the invention shown in Figures 3 to 10, it should be noted that the respective heating elements are electrically heated to a suitable power supply. It is considered that in each case the power supply can be a "battery or a battery pack, which can be attached in a fixed or integral manner to the respective device." Optionally, the battery or the battery pack could be assembled or It is within the scope of the invention that other standard sources of electrical power, such as transformers, can also be used separately, such as on a fastening or belt element for use by the operator. heating such "as fuel, for example, butane, or chemical reactions. - • As mentioned above, one aspect of the invention relates to the optimization of (1) the application of thermal energy, ie, temperature and time, and (2) pressure, i.e. strength and duration, to achieve the maximum tissue sealing strength and the minimum damage to the collateral tissue. Those skilled in the art will appreciate that these useful parameters will vary greatly. However, in the practical application to a human tissue a voltage of about 0.5 volts to about 14 volts, preferably from about 1 volt to about 12 volts, 3 '9 will apply to the heating element having sufficient strength to generate thermal energy to heat tissue to a suitable temperature to cause protein denaturation. This temperature is in the range of about 45 ° C to about 100 ° C. The applied pressure would be sufficient to provide coadaptation but less than that which would crush or destroy the tissue itself. The strength of coagulations, seals, anastomoses, or tissue welds can be measured experimentally. For example, the force of a coagulation produced on one side of a lacerated blood vessel can be measured experimentally by first producing the coagulation and then applying measured amounts of hydrostatic pressure to the inside of the vessel until the coagulation burst and the bleeding starts again. . The strength of a tissue weld can be measured by first joining two pieces of tissue together and then placing the tissues together in a machine that attempts to pull the tissue apart with increasing amounts of force and measurements. The collateral thermal damage is also a measurable quantity because the amount of collateral thermal damage can be easily assessed visually or microscopically.With the use of this methodology, a table of parameters optimized for any type of tissue could be constructed. in various devices by means of selecting the voltage, current, and resistance of the heating elements and also the amount of pressure used to press the tissue during the coagulation / sealing / joining process, as well as the duration of the process time These parameters can simply be incorporated into the device (ie, a simple mechanical stopwatch, pre-set voltage and current, and pressure devices loaded with springs, or, we can incorporate more flexible and active controls based on the microprocessor regulation of the heating process, guided by a "consult" table in a memory read-only and using sophisticated mechanical force / pressure sensors and voltage meters). Also, for certain applications, it may be sufficient to have an experienced operator, visually or by other sensitive means, determine the duration of the application of energy and the amount of pressure required. The devices of the present invention can be constructed of any convenient material, such as would be familiar to one skilled in the art, for example, a constructed plastic such as reinforced glass fiber, polycarbonate, or machined or injection molded ceramic, or glasses at high temperature or epoxy, or mica. Alternatively, they may be constructed of steel of suitable alloys such as 318 stainless steel, or the like. The heating element can be a simple resistive wire or it can be a thin film or coating composed of metallic, metallic organic materials, or organic materials that can be conductive or semiconductor. Actual building materials will be a matter of choice depending on whether the device is to be used repetitively or disposably. Of course, in the latter situation it is contemplated that different parts of the device can be constructed of a metal alloy and / or plastic, in this situation the disposable plastic components can be pulled after each use and the components of metal alloys more expensive to reuse. If sophisticated and expensive control circuits are used, this part of the device could be made in a reusable manner. It is intended that the entire subject or object contained in the above description and shown in the accompanying drawings be construed as illustrative and not in a limiting sense. Also, it is understood that the following claims are intended to cover all the generic and specific characteristics of the invention described herein and all the statements of scope of the invention which, as a matter of language, could be said to fall between them.

Claims (25)

1. CLAIMS 1. A device for sealing and cutting tissue which comprises: an elongated member having a distal and proximal end, the proximal end thereof being joined to a handpiece, two upper and lower jaw members positioned opposite each other having each one end proximal and distal and each having a work surface, the jaw members positioned at the distal end of the elongate member and rotatably joined together; a cutting element positioned on or adjacent to the work surface of the jaw member; and _ a heating element located on or on the working surface of at least one jaw member. The device of claim 1, wherein the cutting element comprises a blade and the blade is operatively connected to a cutting blade activator. The device of claim 1, wherein the device also comprises a battery pack attached to the handle and electrically connected to the heating element. 4. The device of claim 1, wherein the heating element is an electrically resistant wire 5. The device of claim 1, wherein an activator of the heating element is operatively connected to the heating element. of claim 1, which also comprises an activator of the jaw member operably connected to "at least one jaw member. The device of claim 1 which is disposable. 8. A method for cutting woven which comprises the steps of: (a) placing tissue within the open jaws of the device of claim 1; (b) closing the jaws to hold the tissue in place, - (c) activating the heating element to cause portions of the tissue to denature and seal or join together; and (d) activating the cutting means for cutting the tissue between the sealed areas of the tissue. The method of claim 8, wherein in steps (b) and (c) the fabric is heated for an optimal time and at an optimum temperature under optimum pressure to maximize the strength of the tissue seal while minimizing damage to the fabric. collateral tissue. A device for joining tissue, which comprises: a fastener for securing the first and second sections of tissue adjacent to each other; a heating element in a fastener for heating tissue, and a pressure element associated with the fastener for generating pressure, wherein the sections of the fabric are heated for an optimal time and at an optimum temperature under optimum pressure to maximize the strength of the seal or tissue union while minimizing damage to collateral tissue. 11. A method for joining tissue, which comprises: placing two sections of tissue each having an area to be joined together, to cause these areas to be adjacent to each other, and applying optimal thermal energy and optimum pressure to cause that the tissue areas are joined together so that the strength of the joint or seal is maximized and damage to the collateral tissue is minimized. A device for joining tubular sections of tissue, which comprises: a rod member having proximal and distal ends, the distal end comprising a substantially hollow hemispherical section, wherein the hollow section faces proximally and has a circular edge, and a first cylindrical member concentrically surrounding the rod member and having proximal and distal ends, the distal end comprising an internal circular cutting edge, and a second cylindrical member concentrically surrounding the first cylindrical member and having proximal and distal ends , the distal end comprising a circular heating element, wherein the rod member is movable within the cylindrical member and the circular edge of the hemispherical section cooperates with the heating element. 13. The device of claim 12, wherein the circular heating element is electrically connected to a power source. A method for tissue anastomosis comprising the steps of: ~ (a) placing the distal end of a first section of tubular tissue having proximal and distal ends around the rod of the device of claim 12, (b) placing the proximal end of a second section of tubular tissue having proximal and distal ends around the distal rod with the distal end of the first section of the tubular tissue, (c) causing the substantially hemispherical section to move proximally to make the hemispherical section press the distal portion of the first section of tubular tissue and the proximal portion of the second section of tubular tissue against the heating element, (d) heat the tissue sections of step (c) to cause tissue sections to come together each other, and (e) causing the inner circular edge to move distally to separate the unnecessary tissue. 15. A method of claim 14, wherein the fabric is heated for an optimal time and at an optimum temperature under optimum pressure to maximize the sealing force of the tissue while minimizing damage to the collateral tissue. 16. A tissue core sample retriever comprising: "a cylindrical member having proximal and distal ends, the distal end comprising a cutting edge, and a handle fixedly attached to the proximal end of the cylindrical member, wherein the cylindrical member has an outer surface containing a heating element electrically connected to an energy source 17. A tissue cutter comprising: a "circular disk having a sharp outer edge and two outer surfaces, one or both of the External surfaces have a circular heating element positioned adjacent the sharp outer edge, a handle rotatably attached to the center of the disk, and a source of energy electrically connected to each heating element. 18. A device for sealing tissue which comprises: (a) an elongate member having distal and proximal ends, the proximal end of which is attached to a handle; (b) two opposing upper and lower jaw members each having proximal and distal ends, and each having a work surface, the jaw members positioned at the distal end of the elongate member and rotatably joined together in their respective proximal ends; and (c) a heating element located on or on the work surface of at least one jaw member. 19. The device of claim 18, wherein the device also comprises a battery pack attached to the handle and electrically connected to the heating element. The device of claim 18, wherein the activator of the heating element is operatively connected to the heating element. The device of claim 18, wherein the jaw member is fixedly attached to the elongated member. 22. The device of claim 18, further comprising an activator of the jaw member operably connected with at least one jaw member. 23. The device of claim 18, which is disposable. 24. In a device for joining sections of tissue wherein the tissue sections are placed adjacent to each other and staples are fired together in the tissue sections to cause them to be joined together, the improvement in which the device also comprises a heating element and a pressure element for heating the tissue sections for an optimal time and at an optimum temperature under optimum pressure to maximize the tissue seal strength while minimizing damage to the collateral tissue. 25. In a device for joining tissue sections where tissue sections are placed adjacent to each other, staples are fired into the tissue section to cause them to join together, and unnecessary tissue is removed, improvement in wherein the device also comprises a heating element and a pressure element for heating the tissue sections for an optimal time and at an optimum temperature under optimum pressure to maximize the strength of the tissue seal while minimizing damage to the collateral tissue.