1. Field of the Invention
The present invention relates generally to devices for cutting a material or substance. More specifically, devices and methods for efficient severing or cutting of a material or substance, such as soft tissue, suitable for use in open surgical and/or minimally invasive procedures, such as percutaneous procedures in breast tissue, are disclosed.
2. Description of Related Art
Standard methods of severing of tissue may include using a scalpel, scissors, and radio frequency energy. Percutaneous procedures in soft tissue such as the breast, however, are difficult to perform using a standard scissors and scalpel as there is no exposed cavity or space as in open surgical procedures. There is continuous pressure or force of adjacent tissue on the cutting device which may affect or impede the operation of the cutting device. Furthermore, in a closed environment, radio frequency current, a common type of energy used to sever tissue, dissipates into the surrounding tissue decreasing the ability to achieve a current of sufficient high density at the cutting electrode to initiate a cut. To overcome this problem, high power settings are often required to initiate the cut which is often painful and increases thermal damage to the tissue.
In a closed environment, it may be difficult for deformable cutting mechanisms to achieve a desired configuration. Often during insertion of a percutaneous device into tissue, the cutting mechanism is housed within a probe or sheath to facilitate insertion. When the cutting mechanism is exposed for example, by advancement out of the probe or retraction of the sheath, the cutting mechanism is still surrounded by the soft tissue. The soft tissue may produce sufficient pressure on the cutting mechanism to prevent the cutting mechanism from attaining a desired shape or configuration. In particular, expandable cutting loops may not fully expand, thereby impeding efficiency of cutting.
A further disadvantage of percutaneous procedures is difficulty in stabilizing tissue during the procedure. Tissue stabilization facilitates cutting of soft tissue by preventing unexpected movement(s) especially as the soft tissue is separated from surrounding tissue. In one example, suction via a vacuum source can be used to hold and stabilize tissue within a trough while a rigid, fixed diameter, oscillating cutter advances over the trough. Only a small core of tissue is obtained with each cut. Multiple cuts are often required to obtain enough cores of tissue for diagnostic accuracy.
Accordingly, there is a need for more efficient severing or cutting of tissue that can be used during minimally invasive procedures such as percutaneous procedures in breast tissue.
Devices and methods for efficient severing or cutting of a material or substance, such as soft tissue, suitable for use in open surgical and/or minimally invasive procedures, such as percutaneous procedures in breast tissue, are disclosed. It should be appreciated that the present invention can be implemented in numerous ways, including as a process, an apparatus, a system, a device, and a method. Several inventive embodiments of the present invention are described below.
A tissue cutting device may generally include one or more deformable cutting assemblies. The cutting assembly may be of any predetermined preformed shape that is generally altered or deformed when in a storage configuration. When in a cutting configuration, the cutting assembly preferably generally returns to the predetermined preformed shape. The cutting assembly has a cross-section that may be rectangular, square, round or any other suitable shape. The cutting assembly may have one or more cutting edges. The cutting edge may be sharpened or have a set of cutting teeth disposed along at least a portion of the cutting edge. At least part of the cutting assembly may be operatively coupled to an energy source such as radio frequency, laser, ultrasonic, heating, cooling, fluid pressure and/or mechanical oscillation and/or rotation. At least part of the cutting assembly may be at least partially insulated.
The cutting assembly may be a cutting loop forming a partial or complete loop. The cutting loop may be circular, oval, square or any other suitable shape, regular or irregular. With multiple cutting loops, one cutting loop may be nested within another cutting loop. For example, a cutting assembly may be configured with a first cutting loop opposing a second cutting loop so that a first set of cutting teeth is aligned with and configured to cooperate with a second set of cutting teeth. One or more of the cutting loops may oscillate and/or rotate.
A tissue cutting device generally includes a probe defining a probe axis and the cutting assembly in a storage configuration or a cutting configuration. The cutting assembly may be at least partially retracted within the probe in the storage configuration and return to the cutting configuration when at least partially extended through one or more openings at or near a distal end of the probe. The probe may include a sheath or cover slidable between a proximal position in which the cutting assembly is at least partially in the cutting configuration and a distal position in which the sheath at least partially houses the cutting assembly in the storage configuration.
In one embodiment, when the cutting assembly returns to the cutting configuration, the cutting assembly can be initially in general alignment with the probe axis and configured to pivot relative to the probe axis about a cutting assembly pivot.
A coagulator may be incorporated into the cutting assembly to facilitate control of bleeding. For example, the coagulator may be disposed on an outer surface of each cutting blade. The coagulator can be coupled to an energy source such as a radio frequency energy, laser, cold, ultrasonic heating, and/or electrical resistive heating source.
A tissue fixator may be incorporated into the tissue cutting device. The tissue fixator may stabilize a region of tissue as it is being cut to facilitate the cutting procedure. The region of tissue may be tissue to be severed and/or tissue adjacent and/or near the tissue to be severed. The tissue fixator may grasp, penetrate or adhere to the region of tissue. For example, as a penetrator, the tissue fixator may be one or more wires that embed into the tissue to be severed. The tissue cutting device may include a base that houses the tissue fixator. The cutting assembly may be movable relative to the base and/or tissue fixator.
A specimen retriever may be incorporated into the cutting assembly and/or the probe. For example, the specimen retriever may be a deformable material that is at least partially attached to the cutting assembly and at least partially encompasses the specimen as the tissue is cut.
An internal retractor may be incorporated into the tissue cutting device. For example, the internal retractor may be disposed around the cutting assembly. When the cutting assembly is exposed to the tissue, for example, by retraction of the sheath and/or by advancement out the distal end of the probe, the cutting assembly may not substantially or fully reconfigure to the desired preformed shape due to pressure from the surrounding soft tissue. The internal retractor may push or retract the soft tissue away from the cutting assembly, facilitating the reconfiguration of the cutting assembly to the desired preformed shape. Where the device is energized using radio frequency, the internal retractor may push or retract the soft tissue away from a cutting electrode to minimize or block the dissipation of current into the soft tissue, thereby facilitating the attainment of sufficient current density on the cutting electrode to initiate the cutting process.
A method for cutting tissue generally includes positioning a distal region of a probe of a tissue cutting device adjacent to or into a region of tissue to be severed, the probe defining a probe axis, generally returning a cutting assembly to a cutting configuration from a storage configuration, activating a specimen fixator and activating the cutting assembly and specimen retriever such that the tissue cutting device severs and collects tissue. Optionally, an internal retractor may be activated prior to activating the cutting assembly.
These and other features and advantages of the present invention will be presented in more detail in the following detailed description and the accompanying figures which illustrate by way of example principles of the invention.
The present invention will be readily understood by the following detailed description in conjunction with the accompanying drawings, wherein like reference numerals designate like structural elements.
FIGS. 4A-F are partial perspective sectional views of a method for fixating, severing and removing a tissue specimen from a breast using an embodiment of the tissue cutting device.
Devices and methods for efficient severing or cutting of a material or substance, such as soft tissue, suitable for use in open surgical and/or minimally invasive procedures, such as percutaneous procedures in breast tissue, are disclosed. The following description is presented to enable any person skilled in the art to make and use the invention. Descriptions of specific embodiments and applications are provided only as examples and various modifications will be readily apparent to those skilled in the art. The general principles defined herein may be applied to other embodiments and applications without departing from the spirit and scope of the invention. Thus, the present invention is to be accorded the widest scope encompassing numerous alternatives, modifications and equivalents consistent with the principles and features disclosed herein. For purpose of clarity, details relating to technical material that is known in the technical fields related to the invention have not been described in detail so as not to unnecessarily obscure the present invention.
The base 300 may be positioned on at least one side of the inner probe 240. The base 300 has a length that generally aligns with the probe axis 224. A distal end of the base 300 may include a base tip 320. The base tip 320 may optionally be sharpened to facilitate insertion into tissue. The base tip 320 may be operatively connected to an external energy source (not shown) such as radio frequency, laser, cooling, heating, ultrasonic, fluid (e.g., liquid and/or gas) pressure to facilitate insertion and positioning in soft tissue. The inner probe 240 is slidable along the length of the base 300, e.g., along the probe axis 224.
The sheath 350 can also be slidable along the length of the inner probe 240, e.g., along the probe axis 224, and the length of the base 300. As shown in
As shown in
Upon application of one or more external stresses, for example, by sliding the sheath 350 around the cutting assembly 400, the elastic and/or superelastic property of the cutting assembly 400 allows the cutting assembly 400 to configure to a storage configuration 424a, generally without the development of a permanent deformity as long as the resulting strains do not exceed the recoverable strain limits of the material of the cutting assembly 400. When the external stress(es) is removed, the cutting assembly 400 preferably returns generally to the cutting configuration 424b. For example, as shown in
In another alternative embodiment (not shown), the cutting assembly 400 may be advanced and/or retracted through one or more openings at or near a distal end of the probe 200. When retracted, the cutting assembly 400 may be housed within the confines of the probe 200 and is in the storage configuration 424a. When advanced through the one or more openings at or near the distal end of the probe 200, the cutting assembly 400 generally returns to the cutting configuration 424b.
The cross-sectional area (not shown) of the cutting assembly 400 may define at least part of a circle, oval, diamond, triangle, rectangle, square, any other polygon and/or any suitable combination of various shapes. The cutting assembly 400 may be energized using radio frequency, laser, ultrasound, heat, cold, oscillation, vibration, rotation, fluid pressure. The cutting assembly 400 may be operatively coupled to an external energy source (not shown). Alternatively, the energy source may be housed within the handle 500. When the cutting assembly 400 is energized by radio frequency energy, the cutting assembly 400 may be configured as a monopolar or a bipolar electrode. Activating or energizing the cutting assembly 400 may be controlled by a cutting controller (not shown) which may be located, for example, on the handle 500 or as a foot control.
The cutting assembly 400 may include one or more additional material(s) (not shown). The additional material(s) may be configured as one or more layers, portions, or segments that are continuous or non-continuous, symmetric or non-symmetric, on the surface and/or within the cutting assembly 400. The additional material(s) may provide properties such as electrical insulation, heat insulation, varying conductivity (e.g., heat and/or electrical), strength, lubricity, and/or sensors (e.g., temperature). The additional material(s) may include ceramics, polymers, plastics, metals, metal alloys, glass, diamonds, diamond-like carbon, diamond-like non-composite coating (metal-doped or nonmetal-doped) and/or various other suitable substances. One or more liquid materials may also be incorporated into the cutting assembly 400 to provide, for example, lubricity and/or heat insulation. Such materials may include, for example, silicone and perfluorinated fluids. Preferably, when radio frequency energy is used as the external energy source, the cutting assembly 400 is at least partially covered with one or more insulating materials to concentrate the cutting current on one or more edges. The insulating material is preferably of sufficient dielectric strength to prevent or reduce dissipation of the cutting current into the tissue and to concentrate the cutting current at one or more edges. Each of the one or more insulating materials is also preferably able to withstand high temperatures potentially generated by the radio frequency energy. The cutting assembly 400 may be formed using techniques and methods known in the art and may include machining, lasering, stamping, and/or chemical etching.
Referring again to
When in the cutting configuration 424b, the cutting loop 420 (not shown) preferably has a diameter of approximately 1 to 3 cm but alternatively may be less than 1 cm or greater than 3 cm. When in the cutting configuration 424b, the cutting loop 420 may have a fixed or variable diameter.
The tissue fixator 460 facilitates in stabilizing a region of tissue during the cutting procedure. Preferably, the region of tissue is the tissue to be severed and/or is the tissue adjacent to or near the tissue to be severed. The tissue fixator 460 is preferably integrated in the tissue cutting device 100, e.g., by being at least part of and/or housed in the base 300, but may alternatively be separate from the tissue cutting device 100. When the tissue fixator 460 stabilizes the tissue to be severed, the tissue fixator 460 may also facilitate in extraction or removal of a specimen (i.e. a volume of tissue that has been severed) from the soft tissue. The tissue fixator 460 may penetrate or grasp the region of tissue and may be one or more hooks, clamps, needles and/or wires of a suitable shape. Alternatively, the tissue fixator 460 may adhere to the region of tissue and preferably attaches to the region of tissue that becomes a margin or edge of the tissue to be severed. The tissue fixator 460 may adhere to the region of tissue via a vacuum connected to an internal or external vacuum source, a biocompatible adhering substance coated or layered on the tissue fixator 460, and/or the tissue fixator 460 may be cooled to a sufficiently low temperature to attach or freeze adjacent tissue thereto. The tissue fixator 460 may be integrated with a specimen retriever 440 such that a combined tissue fixator and specimen retriever mechanism achieves both tissue fixation and specimen retrieval.
Referring again to
As shown in FIGS. 1A-D, the specimen retriever may be a deformable material or membrane that at least partially encompasses the specimen as the tissue is severed. The deformable material or membrane may be formed from a plastic, polymer, a metal, metal alloy or any deformable material, in any suitable composition, combination or variation. The polymer may be any single or combination of polyethylene, polypropylene, polyamide, polyimide, polyester, polyvinyl chloride, polyvinyl fluoride, and polytetrafluoroethylene. The specimen retriever 440 may be reinforced such as in regions or areas that may undergo more stress. Although not shown, the specimen retriever 440 may alternatively be an adherent, a penetrator or a grasper. As an adherent, the specimen retriever may comprise a cooled region of sufficient low temperature to freeze and adhere to the specimen, a region layered or coated with a biochemical adhering substance and a vacuum attached to a vacuum source. As a penetrator, the specimen retriever may be comprised of one or more wires, needles, hooks or the like.
Returning to FIGS. 1A-D, the specimen retriever 440 configured as a deformable material is shown attached in part to the cutting assembly 400 and also surrounds at least part of the base 300. As the cutting assembly 400 severs tissue, the specimen retriever 440 at least partially encompasses the severed tissue to facilitate retrieval of the specimen.
In an alternative embodiment as shown in the partial perspective view of
It is noted that, although not shown, various additional components may be incorporated in the tissue cutting device 100. For example, a coagulator may be incorporated into the cutting assembly 400 to facilitate control of bleeding. The coagulator may be disposed on an outer surface of each cutting blade. The coagulator may be coupled to an energy source such as a radio frequency energy, laser, cooling, ultrasonic heating, and/or electrical resistive heating source. The coagulator may be an inductive coil configured around at least a portion of at least one of the first and second cutting blades. An energy source may be coupled to the coagulator to deliver an electrical current through the inductive coil to cause at least part of the cutting assembly 400 surrounded by the inductive coil to increase in temperature through inductive heating. A temperature sensor may also be incorporated into the cutting assembly 400 to provide a feedback mechanism for controlling a temperature of at least one of the cutting blades and the coagulator.
As a further example of an additional component, a tissue marker may be included in the cutting assembly 400. The tissue marker may be one or more dyes provided on the cutting assembly 400 and/or the tissue fixator 460. The one or more dyes may mark the specimen, preferably as the tissue is severed, to enable identification of specific sides or margins of the specimen for later orientation, for example, superficial margin, deep margin, and/or lateral margin, in relation to the breast from which the specimen was removed. As yet another example, an imaging, tracking, and/or locating device may be incorporated into the tissue cutting device 100. For example, the imaging, tracking, and/or locating device may be a light operatively connected to an internal or external source. As yet a further example, the tissue cutting device 100 may include one or more channels for evacuation of fluids and/or material from the cutting area and/or for instillation of fluid(s) and/or other substance(s) into the cutting area. The one or more channels may be operatively connected to a vacuum source and/or to a source(s) for fluid and/or other substance(s).
The lesion 650 may be targeted using a medical targeting device (not shown). Preferably the medical targeting device is an imaging device such as a device for ultrasound imaging, magnetic resonance imaging, computerized tomography, positron emission tomography, nuclear and x-ray imaging. The imaging device may use analog and/or digital imaging technologies. The imaging device produces two-dimensional, three-dimensional and/or four-dimensional images. Preferably the imaging device images at least part of the lesion 650, the estimated volume of tissue 680 and at least a portion of the probe 200 of the tissue cutting device 100. The medical targeting device may be positioned adjacent to the skin surface 602, at a distance from the skin surface 602 and/or within the breast 600. When located in the breast 600, the medical targeting device may be attached to or incorporated in the tissue cutting device 100 or may be separate from the tissue cutting device 100. Preferably the medical targeting device is also used to guide the procedure using the tissue cutting device 100. Although not shown, one or more locators may also be positioned on the tissue cutting device 100, preferably at or near a distal end of the probe 200. The locators provide a different and/or enhanced method of identifying at least part of the probe 200 within the tissue, for example, using any suitable type of light emission. A locator sensor preferably located external to the skin may be utilized to detect and identify the position of the locator.
After the estimated volume of tissue 680 is determined, the breast 600 is prepared and local anesthetic may be administered using standard surgical technique. A skin incision 690 is made preferably using a surgical scalpel and preferably at a border of the nipple/areolar complex 604. As shown in
The process or method for fixating, severing and removing a tissue specimen from a breast 600 using the tissue cutting device 100 is now described in more detail with reference to
The cutting loop 420 may be activated to facilitate severing or cutting of the tissue and is pivoted or raised, e.g., to approximately 90° relative to the probe axis 224 as shown in
After the cutting loop 420 is raised, the base 300 may be stabilized manually or by a mechanism (not shown) located on the tissue cutting device 100. For example, a spring positioned between the base 300 and the handle 500 may be activated to apply sufficient pressure to the base 300 in a direction opposing direction 362 so as to prevent the base 300 from moving in the direction 362 as the inner probe 240 containing the cutting loop 420 and sheath 350 are retracted in the direction 362. With the base 300 stabilized and in a relatively fixed position relative to the breast 600, the inner probe 240 and sheath 350 are retracted toward and at least partially out of the skin incision 690 to move the cutting loop 420 in direction 362, thereby creating a generally circumferential separation of the specimen 682 from the breast 600. The inner probe 240 and sheath 350 are retracted until the cutting loop 420 is generally proximal to the estimated volume of tissue 680 relative to the skin incision 690 such that when the cutting loop 420 is lowered, the cutting loop 420 is proximal to the estimated volume of tissue 680 as shown in
At the initiation of the cut as the cutting loop 420 is raised, the specimen retriever 440 configured from a deformable material and at least partially attached to the cutting loop 420, is expanded. The specimen retriever 440 generally encompasses and at least partially isolates the specimen 682 from the surrounding tissue as the cutting loop 420 is retracted. The base 300 remains adjacent to the first margin of the specimen 682. In the method herein described, the specimen retriever 440 surrounds at least part of the base 300 in addition to the specimen 682. In an alternative (not shown), the specimen retriever 440 adheres or attaches to part of the specimen 682. The specimen retriever 440 may be may be cooled to a temperature sufficient to freeze and attach to part of the specimen 682, a biochemical adhering substance or a vacuum attached to a vacuum source. In a further alternative (not shown), the tissue fixator 460 and the specimen retriever 440 are integrated.
As shown in
While the exemplary embodiments of the present invention are described and illustrated herein, it will be appreciated that they are merely illustrative and that modifications can be made to these embodiments without departing from the spirit and scope of the invention. Thus, the scope of the invention is intended to be defined only in terms of the following claims as may be amended, with each claim being expressly incorporated into this Description of Specific Embodiments as an embodiment of the invention.
This application is related to co-pending U.S. patent application Ser. No. 10/815,912 (Attorney Docket No. MNOAP008), entitled “Tissue Cutting Devices and Methods” and filed on Mar. 31, 2004, the entirety of which is incorporated by reference herein.