Abstract:
A surgical instrument guide for facilitating treatment of a target tissue is provided. The surgical instrument guide may be placed between two groups of tissue such that a first group of tissue is cut and a second group of tissue is protected from being cut. The surgical instrument guide may lift tissue and slide tissue along a surface so that a target tissue may be cut to a desired depth more easily during a surgical procedure. The surgical instrument guide may be releasably attachable to a surgical instrument or integrally formed therewith.

Description:
RELATED APPLICATIONS 
       [0001]    The present application claims the benefit of U.S. Provisional Application Ser. No. 61/486,623, filed May 16, 2011, which is incorporated herein in its entirety. 
     
    
     THE FIELD OF THE INVENTION 
       [0002]    The present invention relates to surgical instrument guides. More specifically, the present invention relates to guides for use with surgical instruments to facilitate cutting of certain tissue while protecting other tissues from being cut. 
       BACKGROUND 
       [0003]    In surgery, a surgeon cuts into tissue at defined locations to access underlying structures or to perform some desirable restructuring of the tissue being cut. Damage to tissues outside of the defined location is usually undesirable. In some cases, a surgeon may wish to prevent damage to tissues underneath a tissue to be cut. Thus, a surgeon may need to carefully examine the depth of the cut while monitoring the length of cut and other variables—such as heat transfer to surrounding tissue, blood loss in the tissue, etc. This monitoring of multiple variables may cause the surgeon to take a slower approach to cutting through tissue or may cause a momentary distraction which results in tissue damage beyond that desired by the surgeon. 
         [0004]    In some cases, a surgeon may use multiple tools to separate a tissue to be cut and other tissue(s) he or she wishes to avoid cutting. The use of multiple tools may demand the surgeon&#39;s otherwise free hand or require the surgeon to switch back and forth between instruments. In fact, in electrosurgical applications, a surgeon may use an instrument to separate or retract tissue with one hand, use the other hand to operate a cutting instrument and control the power output with a foot pedal to avoid having to let go of either the cutting instrument or the separating/retracting instrument. Thus, a surgeon may have to concentrate on simultaneously using at least three of his or her appendages during an operation. 
         [0005]    Thus, there is a need for an improved device and method for reducing the number of variables that require the surgeon&#39;s attention such that the speed of surgery may be increased and/or the risk to the patient may be decreased. Additionally, it is desirable that the improved device and method reduce collateral tissue damage outside of a defined surgical location. 
       SUMMARY OF THE INVENTION 
       [0006]    It is an object of the present invention to provide an improved to surgical instrument guide. 
         [0007]    According to one aspect of the invention, a surgical instrument guide may be placed between two groups of tissue such that a first group of tissue is cut and a second group of tissue is protected from being cut. 
         [0008]    According to another aspect of the invention, a surgical instrument guide may lift tissue and slide tissue along a surface such that the tissue stretches and a straight cut may be made more easily during a surgical procedure. As the cutting blade or surgical element may be recessed within the guide, the guide may lift and direct a cut such that cutting does not release an adjacent portion of tissue that may be cut. 
         [0009]    According to another aspect of the invention, the surgical instrument guide may be attached to existing surgical instruments either permanently, or may be attached and removed whenever desired. 
         [0010]    These and other aspects of the present invention are realized in a surgical instrument guide as shown and described in the following figures and related description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0011]    Various embodiments of the present invention are shown and described in reference to the numbered drawings wherein: 
           [0012]      FIG. 1  shows a perspective view of the working end of a surgical tool with a surgical instrument guide attached thereto; 
           [0013]      FIG. 2  shows a perspective view of the surgical tool of  FIG. 1  cutting through tissue with the surgical instrument guide attached; 
           [0014]      FIG. 2A  shows a side view of the surgical tool of  FIG. 1  and the surgical instrument guide cutting through a top layer of tissue while preventing the cutting of a lower layer of tissue. 
           [0015]      FIG. 3  shows a perspective view of a surgical instrument guide according to principles of the present invention; 
           [0016]      FIG. 4  shows a front view of a surgical instrument guide; 
           [0017]      FIG. 5  shows a rear view of a surgical instrument guide; 
           [0018]      FIG. 6  shows a side view of a surgical instrument guide; 
           [0019]      FIG. 7  shows a top view of a surgical instrument guide; 
           [0020]      FIG. 8  shows a bottom view of a surgical instrument guide; 
           [0021]      FIG. 9  shows a perspective view of a surgical instrument having an integral surgical instrument guide; 
           [0022]      FIG. 10  shows a perspective view of a snap-on surgical instrument guide; 
           [0023]      FIG. 10A  shows a fragmented, perspective view of a surgical instrument and a surgical instrument guide according to principles of the present invention; 
           [0024]      FIG. 11  shows a side view of an upward ramp surgical instrument guide generally positioned perpendicular to the surgical instrument; 
           [0025]      FIG. 12  shows a side view of a downward ramp surgical instrument guide generally positioned perpendicular to the surgical instrument; and 
           [0026]      FIG. 13  shows an inline ramp surgical instrument guide. 
       
    
    
       [0027]    It will be appreciated that the drawings are illustrative and not limiting of the scope of the invention which is defined by the appended claims. The embodiments shown accomplish various aspects and objects of the invention. It is appreciated that it is not possible to clearly show each element and aspect of the invention in a single figure, and as such, multiple figures are presented to separately illustrate the various details of the invention in greater clarity. Similarly, not every embodiment need accomplish all advantages of the present invention. 
       DETAILED DESCRIPTION 
       [0028]    The invention and accompanying drawings will now be discussed in reference to the numerals provided therein so as to enable one skilled in the art to practice the present invention. The drawings and descriptions are exemplary of various aspects of the invention and are not intended to narrow the scope of the appended claims. 
         [0029]    Turning now to  FIG. 1 , there is shown a perspective view of the working end of a surgical instrument  10  engaged with a surgical instrument guide  20  according to principles of the present invention. The working end of the surgical instrument  10  may engage the surgical instrument guide  20  to aid in surgery. The surgical instrument guide  20  may aid the surgeon in treating a target tissue while substantially preventing undesired damage in other tissue adjacent the target tissue. For example, the surgical instrument guide  20  may facilitate cutting of the target tissue while substantially preventing cutting of tissue adjacent the target tissue. It will be appreciated that the term “tissue” as used herein may refer to a single tissue type, a single tissue layer, multiple tissue types, multiple tissue layers, and/or other material on which a surgical instrument may be used. 
         [0030]    In accordance with one aspect of the invention, a surgical instrument guide may cause a target tissue to be spaced apart from a tissue adjacent the target tissue prior to and/or during treatment of the target tissue by a surgical instrument. For example, the surgical instrument guide  20  may lift up and direct a target tissue toward an active element  50  of the surgical instrument  10 . By lifting and directing the target tissue, a degree of separation and/or barrier may be made between the target tissue being cut and other tissue thus substantially preventing damage to the other tissue by the active element  50 . The active element  50  may use thermal energy to treat tissue. For example, the active element  50  may include a ferromagnetic coated conductor to treat tissue such as thermally adjustable ferromagnetic conductors disclosed in U.S. Publication Nos. 2010-0268207, 2010-0268214, 2010-0268208, 2010-0268209, 2010-0268215, 2010-0268205, 2010-0268210, 2010-0268212, 2010-0268213, 2010-0268211, 2010-0268216, 2010-0268206, all of which are expressly incorporated herein by reference. 
         [0031]    The guide  20  may engage the surgical instrument  10  such that a sufficient transfer of thermal energy from the active element  50  to the guide  20  in order to heat the guide is substantially prevented. Under these circumstances, the likelihood of thermal damage to any tissue contacted by the guide  20  is decreased or even eliminated. Thus, the guide  20  may aid a user to direct the active element  50  of the surgical tool to only specific tissue. 
         [0032]    The working end of the surgical tool  10  may include a body  30 , a tip  40  and an active element  50 . The active element  50  may be a conventional cutting blade or an electrosurgical cutting element. The surgical instrument guide  20  may include a coupling member, such as a collar  60 , an arm  70  which extends away from the surgical instrument  10  and a tissue shield  80  formed as a foot or other extension for protecting tissue other than the target tissue from being cut, etc. The surgical instrument guide  20  may be attached to the surgical instrument  10  by connecting the coupling member  60  to the body  30 , for example, by slidably engaging the coupling member  60  with the body  30 . The arm  70  may extend past the tip  40  such that tissue shield  80  is positioned a short distance beyond the active element  50 . The tissue shield  80  has a top surface  100  and a bottom surface, and may include a channel, groove or depression  90  that allows the active element  50  to extend beyond the top surface  100  (but preferably not below the bottom surface) of the tissue shield  80  without contacting the tissue shield  80 . Thus, the active element  50  may be said to intersect a plane extending along the top surface  100  of the tissue shield  80 . According to one aspect of the invention, the guide  20  is connected to the surgical instrument  10  such that the active element  50  extends into the channel  90 . Thus, the active element  50  may engage tissue that is positioned across the top surface  100  of the tissue shield  80  (e.g. the target tissue) and cut completely through the target tissue while the tissue shield  80  prevents the active element  50  from contacting tissue(s) along the bottom surface of the tissue shield  80 . 
         [0033]    A chamfer, incline or wedge, etc.  110  may be used to engage a target tissue and aid in lifting the target tissue away from other tissue(s) prior to treating the target tissue using the active element  50 . As the wedge  110  slides along the tissue, it lifts the target tissue away from lower tissues and stretches it slightly over and across the top surface  100  of the tissue shield  80  and channel  90 . This facilitates cutting the tissue cleanly. Tissue that is not pulled to the top of the tissue shield  80  may be pushed under the tissue shield  80 . Thus, the tissue shield  80  may act as a barrier to prevent damage to any tissue under the tissue shield  80  caused by the active element  50 . 
         [0034]    It should be recognized that while the tools may be discussed in a surgical sense, such as surgical instrument  10 , the system may have applicability in other areas, such as the cutting of meat or other membranes. For ease of understanding, however, the system may be described in a surgical context. 
         [0035]    Turning now to  FIG. 2 , a perspective view of a surgical instrument  10  with guide  20  cutting through tissue  120  is shown. When the surgical instrument  10  is moved in a forward direction, the wedge  110  ( FIG. 1 ) of the tissue shield  80  lifts the tissue  120  up and away from structures beneath the tissue  120  and slides along the tissue  120  as the active element  50  is advanced. As the active element  50  may cut the tissue  120 , the cut portions of the tissue slide by the arm  70  which may be beveled or otherwise contoured depending on the application. Thus, the guide  20  may ensure that the cut along tissue  120  is made at a desired depth allowing the user to focus on the direction of the cut. Therefore, the tissue guide  20  may allow the user to perform a quicker cut with less risk of unintended damage. 
         [0036]    Turning now to  FIG. 2A , there is shown a side view of a the working end of a surgical instrument  10  as shown in  FIGS. 1 and 2  as the guide  10  is moved through a first layer of tissue  124  above a second layer of tissue  128 . Those skilled in the art will appreciate that there are numerous situations in which a surgeon desires to cut one layer of tissue and not another. For example, the spinal cord is wrapped in a membrane called the Dura Mater. A surgeon may need to access the spinal cord, but does not desire to cut into the spinal cord. To open the Dura Mater, the physician need only make a very small incision in the membrane and then slide the tissue shield  80  through the incision so that the tissue shield is disposed between the spinal cord and the Dura Mater. Once this is accomplished, the surgeon can cut along the Dura Mater without fear that he or she is also cutting into the spinal cord. There are numerous similar structures in the body where it is desirable for one layer of tissue to be cut without cutting an adjacent layer of tissue. The guide  20  both protects the underlying tissue  128  and lifts and helps separate the upper tissue  124  during cutting, thereby simplifying the procedure for the surgeon. 
         [0037]    Turning now to  FIGS. 3 to 8  generally, different perspectives of a surgical tool guide  20  are shown.  FIG. 3  shows a perspective view of the surgical guide  20 . It will be appreciated that the guide  20  may be independent from the surgical instrument  10  with which the guide  20  is used. The guide  20  may be snap fit, have a threaded engagement or otherwise attach to the surgical instrument  10 . Thus, in some embodiments, the guide  20  may be used only when desired and then removed so as to not interfere with the surgeon&#39;s use of the surgical instrument  10  during the remainder of the procedure. 
         [0038]    As shown in  FIG. 3 , the lower portion of tissue shield  80  of the guide is disposed generally perpendicular to the arm  70 . It will be appreciated that a variety of angles may be desirable for use in different medical procedures and the view in  FIG. 3  should be deemed to be only exemplary of the principles of the present invention. 
         [0039]      FIG. 4  shows a front view of a surgical tool guide shown in  FIGS. 1-3 .  FIG. 4  provides a clearer view of the groove or channel  90  into which the cutting or active element (not shown) may extend so as to clearly cut through tissue passing up the incline or wedge  110  and over the top surface  100  of the tissue shield  80 . 
         [0040]      FIG. 5  shows a rear view of a surgical instrument guide  20 . While the arm  70  is shown as being fairly broad, it will be appreciated that the arm  70  can be thin and may be tapered or have a beveled edge to facilitate spreading apart of target tissue or tissues which are cut. 
         [0041]      FIG. 6  shows a side view of the surgical instrument guide.  FIG. 6  provides a better view of the incline or wedge  110  at the front of the tissue shield  80  that helps lift the target tissue over the channel  90  to facilitate cutting of the target tissue. 
         [0042]      FIGS. 7 and 8  show a top view and bottom view, respectively, of the surgical instrument guide  20  shown in  FIGS. 1-6 . The top view looks through an opening in the coupling member  60  through which a portion of a surgical instrument may extend, such as the working end of a scalpel or electrosurgical element. The coupling member  60  may include a variety of attachment mechanisms for holding the guide  20  in place, such as depressions or projections which interact with the tool, a snap fit, etc.  FIG. 7  also shows a top view of portions of the tissue shield  80 , including the depression or channel  90  and the incline or wedge  110  which lifts the target tissue onto the top surface  100  of the tissue shield  80  for cutting. 
         [0043]      FIGS. 1-8  show various parts of the surgical tool guide  20 . For example, a surgical tool guide  20  according to principles of the present invention may include a coupling member  60  (such as a collar), an arm  70  and a tissue shield  80 . The tissue shield  80  may contain a channel or depression  90 , a top surface  100  and a wedge  110 . It will be appreciated that the embodiment shown in  FIGS. 1-8  is intended to be exemplary only, and are not intended to limit the scope of the principles of the present invention. 
         [0044]      FIGS. 9 and 10 , show different mechanisms of connecting the guide  20  to a surgical instrument  10 . The guide  20  may be attached or coupled to the surgical tool  10  in multiple ways. In  FIG. 9 , the guide  20  is integrally formed with the surgical instrument body  30  and thus remains with the surgical instrument throughout use. The arm  70 , integrally formed with the surgical tool body  30 , extends down to the tissue shield  80 . Thus, the entire device body, including the guide  20 , may be formed as one piece. 
         [0045]    In  FIG. 10 , the guide  20  includes a snap-on collar  130 . According to one aspect of the invention, the snap-on collar  130  may be held on by elastic force. According to another aspect of the invention, a collar joint  140  includes a protrusion  144  from a first collar section  150 A that slides into a channel  154  of a second collar section  150 B. The engagement between the protrusion  144  and the channel  154  may lock and thus become essentially permanent, or may be releasable. 
         [0046]    While the figures show a channel or depression  90 , it should be recognized that other configurations are possible. For example, the tissue shield  80  may be constructed without a channel  90  and the active element  50  may extend so as to be substantially adjacent the top surface  100  of the top surface  100  of the tissue shield  80 . According to another aspect of the invention, the active element  50  may extend into the tissue shield  80  as shown in  FIG. 10A . 
         [0047]    Turning now to  FIGS. 11 to 13 , variations of the tissue shield  80  of the guide  20  are discussed. More specifically, the tissue shield  80  and wedge  110  may be altered according to the surgical need. Thus, the angle at which the tissue shield  80  is disposed relative to a surgical instrument  10  may vary and the wedge  110  may be altered to match the desired use and/or positioning of the surgical instrument guide  20 . 
         [0048]    In  FIG. 11 , a side view of an alternate configuration of a surgical instrument guide  20   a  is shown. As shown, the surgical instrument  10   a  may be held at about a right angle relative to the target tissue to be cut. The guide  20   a  includes a tissue shield  80   a  which may extend at about a 90 degree angle relative to the surgical instrument  10   a  and/or arm  70   a  for spacing the tissue shield from the surgical instrument. The incline or wedge  110   a  may have an upper surface  100   a  with an upward slope. The upward slope causes the target tissue to be lifted along the upper surface  110   a  of the tissue shield  80   a  where it contacts the active element  50 . The active element  50  may extend into the tissue shield  80   a , rather than extending into a depression therein. 
         [0049]    Turning now to  FIG. 12 , a side view of surgical instrument  10   b  and surgical instrument guide  20   b . Rather than an upward incline similar to  110  and  110   a  in the figures discussed above, the guide  20   b  includes a downward incline along the tissue shield  80   b  when the surgical instrument  10   b  is held vertically. The downward incline  110   b  allows the tissue shield  80   b  to function as a hook. The leading edge  80   b ′ can be placed under a target tissue to be cut and the surgical instrument  10   b  drawn through the target tissue. The hook-like tissue shield  80   b  lifts the tissue to be cut into contact with the active element  50   b , to thereby assist in cutting the target tissue. It also helps prevent tissue(s), other than the target tissue, from contacting the active element  50   b.    
         [0050]    Turning now to  FIG. 13 , an inline ramp surgical instrument guide  20   c  is shown. As can be seen, the guide  20   c  may allow the surgical tool  10   c  to be held behind the desired direction of cutting, with the action of pushing the active element  50   c  along the desired direction of the cut. The wedge or incline  110   c  at the front of the tissue shield  80   c  is placed underneath the target tissue and pushed along the direction of the cut. The tissue shield  80   c  may extend substantially parallel or in-line with the surgical instrument  10   c  and/or from an arm  70 . The wedge  110   c  may have a surface  100   c  having an upward slope toward the active element  50   c . The upward slope causes the tissue to be lifted along the top surface  100   c  of the tissue shield  80   c  to the active element  50   c.    
         [0051]    There is thus disclosed a surgical instrument guide. The guide assists a surgeon in cutting through a first layer of tissue, a membrane, etc., while protecting tissue or other physiological structures below or adjacent the target material from being cut. Thus, it will be understood that the term tissue shield may also refer to protecting structures other than tissue. It will be appreciated that numerous changes may be made to the present invention without departing from the scope of the claims.