Abstract:
Disclosed herein is a surgical instrument having a cylindrical tube affixed thereto. A guidewire can be threaded through the cylindrical tube to allow for advancement of the surgical instrument to a surgical site.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    The present application claims priority to U.S. Provisional Application Nos. 61/864,070, filed Aug. 9, 2013 and 61/952,386, filed Mar. 13, 2014, the entire contents of which are incorporated by reference in their entirety. 
     
    
     FIELD OF THE INVENTION 
       [0002]    The invention is directed to a surgical instrument having a cylindrical tube for accommodating a guidewire therein. 
       BACKGROUND OF THE INVENTION 
       [0003]    Surgical instruments, such as scalpels, are used to make an incision in the skin, enabling insertion of devices whose purpose is to deliver various substances to the body. In order to minimize the size of the incision, a guidewire is inserted into the body cavity and instruments can be reliably advanced over the guidewire and into the body cavity for proper placement. This method is known as the “Seldinger Technique.” In many circumstances, the guidewire incision needs to be widened in order to accommodate larger medical devices such as a trocar or catheter. The enlargement is typically done by hand which may lead to an imprecise or larger than needed cut. Therefore, a need clearly exists for a surgical instrument capable of using the guidewire to aid a surgical device, such as a scalpel, in making a more precise incision 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0004]      FIGS. 1 and 2  are perspective views of the surgical instrument. 
           [0005]      FIG. 3  is a side view of the surgical instrument of  FIGS. 1 and 2 . 
           [0006]      FIG. 4  is an enlarged rear ¾ view to illustrate one possible locking mechanism for the sliding cover 
           [0007]      FIG. 5  is a side view of the surgical instrument after the blade of the surgical instrument has been exposed. 
           [0008]      FIG. 6  is a cutaway view of the blade of the surgical instrument. 
           [0009]      FIG. 7  is a side view of the blade of the surgical instrument. 
           [0010]      FIG. 8  shows the device with the guide wire inserted as it will be during the procedure. 
           [0011]      FIG. 9  is a perspective view of a first half of the surgical instrument in an unassembled state. 
           [0012]      FIGS. 10 and 11  are perspective views of a second half of the surgical instrument in an unassembled state. 
           [0013]      FIG. 12  is a view of an alternate embodiment of the surgical instrument. 
           [0014]      FIGS. 13-15  are views of another alternate embodiment of the surgical instrument in which the handle is detachable. 
           [0015]      FIGS. 16-18  are views of an alternate embodiment of the invention where the cylindrical tube is detachable/replaceable. 
           [0016]      FIGS. 19-23  are views of another alternate embodiment of the invention wherein the cylindrical tube is an over molded metal tube. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0017]    With reference to  FIGS. 1-3 , depicted is surgical instrument  100  having proximal end  102  and distal end  104 . Surgical instrument  100  generally comprises body  106  and cover  108 . The distal end  104  of surgical instrument  100  is formed as a handle to allow a user to grip and operate the surgical instrument. In a preferred embodiment, body  106  and cover  108  are formed from a surgical grade plastic material. However, any suitable material, such as stainless steel or other plastic/metal, may also be used. 
         [0018]    Body  106  comprises grooves  110  and raised stop  112 . Detents formed on cover  108  (not shown) interlock with grooves  110  to allow cover  108  to slide over body  106  from a closed position ( FIG. 3 ) to an open position ( FIG. 4 ). Raised stop  112  prevents cover  108  from being moved to an open position without intervention by a user. 
         [0019]    Body  106  further comprises a cylindrical tube  114  attached to a top surface of body  106 . Preferably, cylindrical tube  114  is formed integral to body  106  and extends substantially the entire length of body  106 . This allows a guidewire to extend behind the operator of surgical instrument  100  so it minimizes interference with a user. The proximal end of cylindrical tube  114  is preferably beveled ( FIG. 5 ). The advantage of the bevel is that it results in a sharp tipped channel for cylindrical tube  114 , allowing the channel to pass through the skin and soft tissue as the clinician makes a dermototomy incision. 
         [0020]    The diameter of cylindrical tube  114  is great enough such that a guidewire may easily be passed therethrough. Only the first several millimeters of the cylindrical tube  114  channel need to be precisely fit the guidewire diameter to ensure that blade  500  is located close to the guidewire. The remaining portion of cylindrical tube  114  may have a wider diameter to minimize friction with the guidewire during advancement of surgical instrument  100 . 
         [0021]    Cover  108  is sized such that it surrounds body  106  as shown in  FIG. 1-3 . Cover  108  comprises channel  402  which is formed so to easily accommodate and slide over raised stop  112  and cylindrical tube  114 . Sidewalls  404  extend downward from channel  402 . Each sidewall  404  has a detent (not shown) that interlocks with grooves  110 . In order to move cover  108  from a closed position ( FIG. 3 ) to an open position ( FIG. 5 ), a user presses button  406  (see  FIG. 4 ). This causes tangs  408  to open outward, away from body  106 . This forms a channel  410  which allows cover  108  to advance without being hindered by raised stop  112 . 
         [0022]    Once tangs  408  advance past the end of raised stop  112 , tangs  108  return to their initial closed configuration. Now, the surgical device  100  is in an open position as shown in  FIG. 5  and cover  108  is locked in this new open position. The length of channels  110  determines how securely that cover  108  is locked in both the open and closed positions of surgical device  100 . Preferably, grooves  110  and raised stop  112  are the same length and begin/end at the same location on body  106 . 
         [0023]    When surgical device  100  is in an open position, blade  500  is exposed. Blade  500  is depicted in  FIGS. 5-7 . As shown, blade  500  comprises cutting edge  502 , opening  504 , and raised edge  506 . Opening  504  is sized such that it locks onto a corresponding button  508  on body  106 . This allows blade  500  to be securely attached to body  106 . Raised edge  506  allows the tip of cutting edge  502  to extend close to the end of cylindrical tube  112 , thus facilitating the centering of the guidewire with blade  500 . Further, raised edge  506  allows a guidewire passed through cylindrical tube  114  to rest flush against the non-cutting edge of blade  500 , eliminating any gaps between the guidewire wire and blade  500 . Blade  500  may be made from any suitable material that is able to retain a sharp, surgical edge such as stainless steel, ceramic, etc. 
         [0024]    Referring again to  FIGS. 4 , cover  108  additionally comprises cutout portion  412  which provides a user access to cylindrical tube  114  to thread the guidewire even when the surgical instrument  100  is in a closed position to minimize the risk of operator injury. The portion of cover  108  which extends in the proximal direction past cylindrical tube  114  serves to protect a user from blade  500  while still allowing easy access to cylindrical tube  114 . 
         [0025]    To use surgical instrument  100 , a guidewire  802  is first threaded through cylindrical tube  114  as shown in  FIG. 8 . Next, the surgical instrument is opened as described with reference to  FIGS. 3-5  to expose blade  500 . The surgical instrument  100  can then be advanced over guidewire  802  to a skin surface in order to make an incision. Because surgical instrument  100  is relatively thin and has no side protrusions extending from it, surgical instrument  100  can easily be advanced through an incision without causing much trauma to adjacent tissue. 
         [0026]      FIG. 12  depicts an alternate embodiment of surgical device  100  having a different mechanism for opening and closing cover  108 . In this embodiment, cover  108  comprises button  1202 , flexible member  1204 , ledge  1206 , and hump  1208 . Preferably, ledge  1206  is u-shaped and extends around both sides of surgical device  100  and is connected to button  1202 . Hump  1208  is preferably a semi-circular ridge extending along a top edge of surgical device  100 . Flexible member  1204  is preferably constructed from a flexible, resilient material (e.g., a plastic) which can survive multiple bends. 
         [0027]    Pressing button  1202  causes flexible member  1204  to flex toward cover  108 , which in turn raises ledge  1206  over hump  1208 . Cover  108  can then be slid to position  1210  (at an end of hump  1208 ). Here, flexible member  1204  returns to its initial unflexed position, thereby preventing further movement of cover  108 . 
         [0028]      FIGS. 13-15  depict another alternate embodiment of surgical device  100  in which the proximal end  104  can be separated from distal end  104 . In this embodiment, distal end  104  comprises detent member  1402  which extends from protrusion  1404 . Preferable, detent member  1402  has a width greater than that of protrusion  1404  and is made of stainless steel or hard plastic. Distal end  102  comprises cutout portion  1406  which is sized to accommodate detent member  1402 . When proximal end  104  is attached to distal end  104 , detent member  1402  locks into cutout portion  1406 , thus firmly locking both ends together. By using this configuration, distal end  104  can be used repeatedly while proximal end  102  can be disposed after use. It should be obvious that the shape of detent member  1402  can be modified to fit onto any variety of existing detachable scalpel handles. 
       Device Manufacture 
       [0029]    Due to the manufacturing difficulties in molding a long narrow slot like cylindrical tube  114 , it is preferable to manufacture body  106  in two halves which can later be joined using sonic welding, adhesive, or any other known methods to secure the two halves. Examples of the two halves that may be joined to form body  106  are depicted in  FIGS. 9-11 . 
         [0030]    Another possible method of overcoming these manufacturing difficulties is to manufacture the handle without the channel but with provisions to accommodate a separately manufactured tube to be added. For example, as depicted in  FIGS. 16-18 , surgical device  100  can be manufacture without cylindrical tube  114  ( FIG. 16 ). Cylindrical tube  114  can be manufactured in a separate process and added to surgical device  100  by inserting cylindrical tube  114  into retaining channel  1602  ( FIGS. 17 and 18 ). Other connection techniques, such as a snap fit connection, can also be utilized. 
         [0031]    In some embodiments, it may be desirable to permanently connect cylindrical tube  114  to surgical device  100 . For example, as shown in  FIG. 19 , cylindrical tube  114  may run the entire length of surgical device  100 . To accomplish this configuration, cylindrical tube  114 , which is preferably stainless steel in this embodiment, is placed in a mold for body  106 . Cylindrical tube  114  is then over molded so that it is encased in body  106  (i.e., cylindrical tube  114  is inserted into the mold and then plastic is injected around it). As shown in  FIG. 20 , the cylindrical tube  114  extends to the back of body  106 . Further, as shown in  FIG. 21 , the front of cylindrical tube  114  protrudes over blade  500 . A guidewire  802  can be inserted through cylindrical tube  114  as shown in  FIGS. 22 and 23  and surgical device  100  can be used as previously described. 
         [0032]    This embodiment of surgical device  100  is similar to that depicted in  FIGS. 1-8 . However, in this embodiment, cylindrical tube  114  is a metal tube that has been integrated into body  106  instead of a molded channel. However, the change in manufacturing does not affect the use of surgical device  100 .