Abstract:
The present invention is a device, system and method for surgical soft tissue lesion excision. The device is designed to be placed into a soft tissue lesion preferably under radiologic guidance and deployed. Once deployed, the shape memory wires of the soft tissue encompassing element form a wire cage surrounding the lesion which acts as an excision guide, encompassing and protecting the lesion during surgical excision of the lesion.

Description:
[0001]    This application claims the benefit of U.S. Provisional Application No. 61/869,825, filed Aug. 26, 2013, entitled SOFT TISSUE LESION EXCISION GUIDE, the disclosure of which is herein incorporated by reference. 
     
    
     BACKGROUND OF THE INVENTION 
       [0002]    1. Field of the Invention 
         [0003]    The present invention relates generally to a device, system and method for performing surgical soft tissue lesion excision, more specifically, to a device, system and method for surgical soft tissue lesion excision performed after radiologic localization of the tissue lesion to be excised. 
         [0004]    2. Description of the Related Art 
         [0005]    In current practice, a patient with a radiologically identified lesion, for example, a breast lesion, which cannot be palpated by a physician, and thus cannot be surgically removed without some sort of guide or marker, is marked by placement of a radiologically guided wire which is placed into the tissue of the radiologically identified lesion. Subsequently, a surgeon during an operation, makes an incision and follows the guide wire down to the lesion, then excises the lesion. There are a number of inherent problems with this procedure as currently practiced. The first is that the currently available guide wires are easily dislodged from the lesion during manipulation during the operation. Second, the guide wire, as currently used, marks only the approximate center of the lesion. As the lesion is surrounded by tissue, and often not palpable by the surgeon&#39;s fingers, thus, the lesion can be inadvertently cut into, incompletely removed, or missed altogether. There is substantial need in the field for a radiologically guided marker which also surrounds and encompasses the lesion to be excised, preventing dislodging, cutting into the lesion, incompletely removing the lesion, or missing the lesion altogether. 
       SUMMARY OF THE INVENTION 
       [0006]    In preferred embodiments, the present invention comprises a radiologically placed soft tissue lesion excision device and system used to mark, encompass, and provide tactile feedback to the surgeon during the surgical removal of a soft tissue lesion. 
         [0007]    In some embodiments, the device and system comprise a soft tissue encompassing element, an insertion element, a deployment element and a removal element. The soft tissue encompassing element comprises three or more shape memory wires, preferably formed from nitinol, or any other shape memory material. Each wire being formed such that it has a straight proximal section and a curved distal section, the curved distal section being pre bent in a generally curvilinear configuration and having the ability to be straightened fully, and then return to its original curvilinear configuration. The three or more shape memory wires are formed into a fixed arrangement such that the straight portions of the wires are generally parallel to and fixed to one another at a proximal end, forming a central axis, and the planes described by the curvilinear portions of the wires each being generally parallel to one another, perpendicular to the central axis, and spaced radially equidistant from one another. 
         [0008]    For example, in a device comprising three wires, the curved portion of each wire would describe a vertical plane generally perpendicular to the central axis formed by the fixed straight portion of the wire. The planes described by the curved portions of the three wires would each be generally parallel to one another and spaced approximately one hundred and twenty degrees from one another. If four wires are used the planes described by the curved portions of the four wires would each be approximately ninety degrees from one another. The central straight portions of the wires being fixed to one another, or to a fixation element, such that the wires maintain their planar orientation rigidly. In a preferred embodiment, an extension wire is fixed to the proximal end of the three or more shape memory wires, or to the fixation element and is configured to extend outward through the skin of a patient and functional to act as a guide for the surgeon to locate the distal end of the encompassing element during an operation. In another embodiment, the extension wire is absent and the three or more shape memory wires are of a length that they can extend out from the lesion past the skin of a patient and act as a guide for the surgeon to locate the distal end of the encompassing element during an operation. 
         [0009]    An insertion element comprises a hollow tube with an inner diameter large enough to admit the soft tissue encompassing element within said inner diameter, and sharp or beveled at one end to allow it to penetrate the tissue through which it is to be inserted. In another embodiment there is an infusion port connected to the inner channel of the hollow tube which may be used to administer a local anesthetic agent prior to deployment of the encompassing element. In another embodiment there are perforations in the distal end of the hollow tube functional to allow the infused liquid into the tissue lateral to the soft tissue lesion. 
         [0010]    A deployment element comprises a second hollow tube, with an outer diameter small enough to fit inside the inner diameter of the insertion element and with an inner diameter both large enough to admit the extension wire of the encompassing element and small enough to prevent the three or more shape memory wires from passing through it. At a proximal end is a flattened portion functional to be pressed upon by a physician&#39;s finger. 
         [0011]    A removal element comprises a hollow tube with an inner diameter large enough to admit the soft tissue encompassing element within said inner diameter, and with a conical bevel at one end configured to guide the curvilinear portions of the encompassing element into the inner diameter of the removal element allowing the encompassing element to be removed from the soft tissue lesion it has been inserted into following surgical excision of the lesion. 
         [0012]    In a first stored configuration, the encompassing element is inserted into the inner diameter of the insertion element with the curvilinear portions of the shape memory wires having a generally straight configuration. The deployment element is inserted into the proximal end of the inner diameter of the insertion element such that the extension wire resides inside the inner diameter of the deployment element and the distal tip of the deployment element abuts the proximal ends of the three or more shape memory wires. In this configuration, the apparatus may be placed through the skin of a patient and into the approximate center of the soft tissue lesion, preferably via radiologic guidance. Once located into the approximate center of the lesion, the deployment element is pushed into the insertion element, deploying the encompassing element outward through the sharpened tip of the insertion element. As the encompassing element is deployed, the tips of the curvilinear portions of the shape memory wires penetrate the tissue and while traveling through the tissue, resume their curvilinear configuration surrounding and encompassing the soft tissue lesion. Once fully deployed, the insertion element and deployment element are withdrawn from the tissue, leaving the encompassing element in place around the tissue and the extension wire exiting from and extending outwardly past the surface of the skin. The patient would then be taken to an operating room and a surgeon would make an incision in the skin, then follow the extension wire down to the encompassing element surrounding the lesion. The surgeon would then excise the lesion encompassed within the encompassing element by cutting along the outer diameter formed by the shape memory wires in their curvilinear configuration surrounding the lesion. Once the lesion has been excised, the removal element is slid down the proximal portion of the encompassing element and the encompassing element pulled into the inner diameter of the removal element, removing the encompassing element from the soft tissue lesion allowing for pathological analysis of the lesion. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0013]    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, and in which: 
           [0014]      FIG. 1  is an exploded perspective view of an embodiment showing one example of a soft tissue lesion excision device according to the present invention; 
           [0015]      FIG. 2  is a side view of an example of a single shape memory wire of the soft tissue lesion excision device in its deployed curvilinear conformation; 
           [0016]      FIG. 3  is a perspective view of an example of a single shape memory wire of the soft tissue lesion excision device; 
           [0017]      FIG. 4  is a side view of an example of a soft tissue encompassing element comprising three or more shape memory wires and an extension wire; 
           [0018]      FIG. 5  is a perspective view of an example of the soft tissue encompassing element; 
           [0019]      FIG. 6  is an end on view of an example of the soft tissue encompassing element; 
           [0020]      FIG. 7  is a top perspective view of an example of the soft tissue encompassing element; 
           [0021]      FIG. 8  is a perspective view of an example of an insertion element of the soft tissue biopsy marking and encompassing device; 
           [0022]      FIG. 9  is a side view of an example of a deployment element of the soft tissue biopsy marking and encompassing device; 
           [0023]      FIG. 10  is a perspective view of an example of the deployment element; 
           [0024]      FIG. 11  is a perspective view of an example of the removal element; 
           [0025]      FIG. 12  is a cutaway view of the distal end of an example of the removal element; 
           [0026]      FIG. 13A  is a side view of an example of a soft tissue biopsy marking and encompassing device in its first loaded position; 
           [0027]      FIG. 13B  is a side view of an example of a soft tissue biopsy marking and encompassing device in its second partially deployed position; and 
           [0028]      FIG. 13C  is a side view of an example of a soft tissue biopsy marking and encompassing device in its third fully deployed position. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0029]    The following description is provided to enable any person skilled in the art to make and use the invention and sets forth the best modes contemplated by the inventor for carrying out the invention. Various modifications, however, will remain readily apparent to those skilled in the art. Any and all such modifications, equivalents and alternatives are intended to fall within the spirit and scope of the present invention. In describing the orientation of the device, the term proximal will refer to that end of the described part closest to the portion. 
         [0030]      FIG. 1  is an exploded perspective view of a soft tissue mass excision guide system  10  including an encompassing device (sometimes referred to as a “soft tissue biopsy marking and encompassing device” or the “apparatus” or the “device”) according to an embodiment of the present invention. In preferred embodiments, the apparatus  10  includes a soft tissue marking and encompassing element (encompassing element)  20  comprising three or more shape memory wires  21  constructed preferably of nitinol, or other similar shape memory material, including elastic or super elastic shape memory material. The term “wire” herein refers to the shape memory material used to form the encompassing elements, regardless of whether they are formed of metal wires, or of non-metal material, such as an elastic polymer. The shape memory wires  21  each having a proximal straight portion  211  and a distal curvilinear portion  212  (detailed in  FIG. 2 ), the curvilinear portion functional to transition between a first straight stored configuration depicted in  FIG. 3  and a second curvilinear deployed configuration depicted in  FIG. 2 . The proximal straight portions  211  of the three or more shape memory wires  21  being aligned in parallel with one another along a central axis, arranged in a radial pattern around said central axis and fixed to one another such that the curvilinear portions  212  are oriented substantially perpendicular to said central axis and generally equidistant from one another as depicted in  FIG. 6 , functional to encompass a soft tissue mass and provide a dissection guide for a surgeon surgically removing said soft tissue mass from the body of a patient. Fixed to the proximal end of the three or more shape memory wires  21  is an extension wire  22  functional to extend outward through the skin of the patient after placement and to provide a directional guide for a surgeon to accurately locate the soft tissue mass encompassed by the soft tissue marking and encompassing element  20 . Fixation of the three or more shape memory wires  21  to one another and to the extension wire  22  can be accomplished by various techniques, including but not limited to welding, soldering, encasement in an epoxy resin, or molded to one another using plastic or metal molding. The three or more shape memory wires  21  may have any of a number of cross sectional shapes including round, squared, triangular or pie shaped such that the three or more shape memory wires are rigidly fixed in their planar orientation in the formation of the soft tissue encompassing element  20 . 
         [0031]    An insertion element  30  comprises a hollow tube having an outer wall  31  and an inner channel  32 . The insertion element is preferably sharpened at one end  33  with the diameter of the inner channel  32  being large enough to admit the full diameter of the soft tissue encompassing element  20 . 
         [0032]    As illustrated in  FIG. 11 , a removal element  50  comprises a hollow tube having an outer wall  51  and an inner channel  52  with the diameter of the inner channel  52  being large enough to admit the full diameter of the soft tissue encompassing element  20 . The inner channel is preferably flared at a distal end  53  forming a conical shape functional to guide the distal curvilinear portions of the shape memory wires  212  into the inner channel  52  of the removal element. 
         [0033]    In preferred embodiments, a deployment element  40  comprises a second hollow tube, having an outer wall  41  and an inner channel  42  and a widened plunger  43  on its proximal end. The deployment element being formed such that the diameter of the outer wall  41  is smaller than the inner diameter of the channel  32  of the insertion element  30  and functional to slide easily inside the inner channel  32  of the insertion element  30 . The inner channel of the deployment element  42  is formed such that it is larger than the diameter of the extension wire  22  but smaller than the diameter of the shelf  23  formed by the combination of the proximal ends of the three or more shape memory wires  21  allowing the distal end of the deployment element to abut said shelf  23  of the shape memory wires  22  and functional to slide the marking and encompassing element distally into the tissue when pressure is applied to the plunger  43 . 
         [0034]      FIG. 2  is a side view of an example of a shape memory wire  21  in its second curvilinear deployed configuration detailing the proximal straight portion  211  and a distal curvilinear portion  212 . 
         [0035]      FIG. 3  is a perspective view of an example of a shape memory wire  21  showing the distal curvilinear portion in its first straight configuration. 
         [0036]      FIG. 4  is a side view of an example of a soft tissue encompassing element  20  in its deployed configuration, the three or more shape memory wires  21  in their second curvilinear configuration, the extension wire  22  extending from the proximal end of the three or more fixed shape memory wires  21 . 
         [0037]      FIG. 5  is a perspective view of an example of a soft tissue encompassing element  20  in its deployed configuration, the proximal straight portions  211  of the three or more shape memory wires  21  being aligned in parallel with one another along an axis, arranged in a radial pattern around said axis and fixed to one another or optionally to an extension wire  22 . 
         [0038]      FIG. 6  is a distal end on view of an example of a soft tissue encompassing element  20  showing the curvilinear portions  212  the shape memory wires  21  oriented substantially perpendicular to the central axis, generally equidistant from one another and functional to encompass a soft tissue mass and provide a dissection guide for a surgeon surgically removing said soft tissue mass. 
         [0039]      FIG. 7  is a perspective proximal end on view of an example of a soft tissue encompassing element  20  detailing the shelf  23  formed by the proximal ends of the three or more shape memory wires  21  against which the distal end of the deployment element  40  abuts in order for the deployment element  40  to push the soft tissue encompassing element  20  out of the distal end of the insertion element  30  during deployment of the soft tissue encompassing element  20 . Fixation of the three or more shape memory wires  21  to one another and to the extension wire being accomplished by any number of various techniques, including but not limited to welding, soldering, encasement in an epoxy resin or molded to one another using plastic or metal molding. 
         [0040]      FIG. 8  is a perspective view of an example of the insertion element  30  as shown by example in  FIG. 1  detailing the outer wall  31 , the inner channel  32 , and the sharpened distal end  33 . 
         [0041]      FIG. 9  is a side view of an example of a deployment element  40  showing the outer wall  41  and plunger  43 . 
         [0042]      FIG. 10  is a perspective view of an example of a deployment element  40  detailing the outer wall  41 , inner channel  42  and plunger  43 . 
         [0043]      FIG. 11  is a perspective view of an example of a removal element  50 . 
         [0044]      FIG. 12  is a cutaway view of an example of a removal element  50  detailing the conical shape at the distal end  53  of the inner channel  52 . 
         [0045]      FIGS. 13  A-C illustrate one working example of the operation of the soft tissue biopsy marking and encompassing device  10 .  FIG. 13A  shows the soft tissue biopsy marking and encompassing device  10  is in a first stored configuration with the curvilinear portions  212  of the shape memory wires  21  in their first straight configuration and with the marking and encompassing element  20  inserted into the inner channel of the insertion element  30 . The deployment element  40  having been inserted through the opposite end of the insertion element  30  and having the extension wire  22  contained within its inner channel  32  such that the distal end of the deployment element  40  abuts the proximal end  23  of the three or more shape memory wires  21 . In this configuration, the apparatus  10  is inserted, preferably under radiologic guidance, through the overlying skin and soft tissue of a patient, and into the soft tissue lesion  60  to be excised. Once it is radiologically confirmed that the tip of the insertion element  30  lies at or near the center of the soft tissue lesion  60 , the plunger  43  is depressed moving the deployment element  40  distally against the ends of the shape memory wires at their shelf  23  and pushing the soft tissue encompassing element  20  outward through the sharpened tip of the insertion element  33 . As the encompassing element  20  is deployed, the tips of the curvilinear portions of the shape memory wires  212  penetrate the tissue and while traveling through the tissue, resume their second curvilinear configuration surrounding and encompassing the soft tissue lesion  60 . 
         [0046]    Once fully deployed, the insertion element  30  and deployment element  40  are withdrawn from the tissue, leaving the encompassing element  20  in place around the soft tissue lesion  60  and the extension wire  22  extending outwardly past the surface of and exiting from the skin of the patient. The patient would then be taken to an operating room and a surgeon would make an incision in the skin, then follow the extension wire  22  down to the encompassing element  20  surrounding the lesion  50 . The surgeon would then be able to safely excise the lesion encompassed within the encompassing element by cutting around the outer diameter formed by the shape memory wires  21  in their curvilinear configuration surrounding the lesion  60 . Following excision of the soft tissue lesion  60  the encompassing element  20  may be removed from the soft tissue lesion  60  by sliding the removal element  50  down over first the extension wire  22  then over the proximal straight portion of the encompassing element  211 . The encompassing element  20  is then drawn up into first the flared conical end  53  of the removal element  50  and then into the inner channel of the removal element  52 , the flared conical end functional to guide the curvilinear portions of the shape memory wires  212  into a more straightened configuration, facilitating the entry of the curvilinear portions of the shape memory wires  212  into the inner channel  52 . 
         [0047]    Those skilled in the art will appreciate that various adaptations and modifications of the just described preferred embodiments can be configured without departing from the scope and spirit of the invention. Therefore, it is to be understood that, within the scope of the appended claims, the invention may be practiced other than as specifically described herein.