Abstract:
A surgical retractor system comprises a support frame and at least one retractor blade. The support frame has a generally horizontally oriented support member comprising a plurality of holes. The surgical retractor has at least one retractor blade which is mateable at a selected position on the support frame. At least one retractor blade of the surgical retractor system has an open access window which provides greater visual and physical access to the surgical field.

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     Not applicable. 
     STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH 
     Not applicable. 
     FIELD OF THE INVENTION 
     The present invention relates to medical devices, in particular to a surgical retractor blade and system. 
     BACKGROUND OF THE INVENTION 
     Even with the advent of minimally invasive surgical techniques, many surgical procedures still require an exposed surgical field for the surgeon to successfully perform. Often, the greater the visibility and access a surgeon has to a surgical site, the greater the probability that a successful outcome will result. Once entry is made into a patient, soft tissue is dissected away further exposing the field. However, the exposed field must be maintained using instruments that do not obstruct either visual or physical access. 
     Surgical retractors are used to maintain exposure and access to a surgical field. There are a variety of retractors, and different surgical protocols require different styles of retractors. For example, in lumbar surgery the retractor needs to be strong enough to overcome the force exerted by the large muscle mass that has been dissected away from the field of exposure, while maintaining a visual field and access by the surgeon. Additionally, retractors are required to partition other soft-tissue components of the surgical field. This need has lead to retractor systems having solid blades connected to a firm blade-holding retractor frame. U.S. Pat. No. 5,520,608 discloses a curved, solid retractor blade useful for orthopaedic surgery. 
     During surgery, it is advantageous to have retractor blades that are removably attachable to a support frame. U.S. Pat. No. 4,421,108 is an example of a quick-release ratcheting holder for a surgical retractor. Other mechanisms for holding a retractor blade in position are disclosed in U.S. Pat. Nos. 4,424,724; 4,467,791; 5,375,481; 5,616,117; and 5,893,831. 
     Accordingly, there exists a need for greater flexibility in a surgical retractor system while improving both visual and physical access by the surgeon to the surgical field. 
     SUMMARY OF THE INVENTION 
     The present invention provides a surgical retractor blade and system useful for surgical procedures, including orthopaedic and spinal surgery. In one embodiment, the surgical retractor blade of the invention is used with a support frame that includes a horizontally oriented support member having a plurality of mounting holes. This surgical retractor system further includes at least one retractor blade which is mateable at a selected position on the support frame. The retractor blade includes an open access window that facilitates both visual and physical access to the surgical wound. 
     The retractor blade of the present invention has a substantially elongated, horizontally oriented mounting portion with a longitudinally extending slot formed therein. The retractor blade also comprises a tissue-retracting portion which is integral with and distal to the mounting portion. The tissue-retracting portion has a first section which is coplanar with the mounting portion, and a second section which is angularly oriented with respect to the first section. The open access window is substantially centrally formed, and it is present in both the first and second sections of the tissue-retracting portion of the retractor. The second section of the tissue-retracting position of the blade is preferably angularly oriented with respect to the first section. The angle of orientation is in the range of about 45° to 135°. 
     The retractor blade also comprises a fastening mechanism that effectively enables it to mate to the support frame in a desired position. In one embodiment, a mounting screw is used to mate the retractor blade to the support frame. Other fastening mechanisms, such as clamping devices, can also be used to fasten the retractor blade to the support frame. 
     The foregoing and other features and advantages of the present invention will be more fully understood from the following detailed description along with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a perspective view of a surgical retractor system of the present invention in use during a surgical procedure; 
     FIG. 2A is a perspective view of the surgical retractor system of FIG. 1; 
     FIG. 2B is an exploded, disassembled view of the system shown in FIG. 2A; 
     FIG. 3A is a perspective view of a surgical retractor system according to another embodiment of the invention; 
     FIG. 3B is an exploded, disassembled view of the system shown in FIG. 3A; 
     FIG. 4 is a plan view of a portion of the retractor system according to one embodiment of the invention; 
     FIG. 5 is a plan view of a portion of the retractor system according to another embodiment of the invention; 
     FIG. 6A is a side elevational view of a retractor blade useful with the present invention; 
     FIG. 6B is a plan view of the retractor blade of FIG. 6A; 
     FIG. 6C is a sectional view of the retractor blade of FIG. 6B at lines  6 C— 6 C; and 
     FIG. 7 is a perspective view of a retractor blade according to the present invention, together with a surgical tool. 
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Referring now to FIG. 1, there is shown a surgical retractor system  10  of the present invention. The retractor system  10  is attached to an operating table (not shown) in a manner well known to those having ordinary skill in the art. The retractor system  10  includes a frame  12 , which is preferably suspended above the patient  14 , common retractor blades  16 , and retractor blades  18  having an access window  19 . The system  10  may also include a supporting arm  20  which may be connected to a support post (not shown) or similar elements to affix and support the retractor system in a desired position. 
     With further reference to FIGS. 1 through 2B and  4 , the retractor system  10  of the present invention further includes one or more fixation elements  22 , such as thumb screws, that are effective to secure retractor blades  16 ,  18  to the frame  12  in a desired position so that tissue can be retracted. In one embodiment, the support frame  12  is a four-sided, substantially rectangular object having a central opening  21 . Each side  12   a ,  12   b ,  12   c ,  12   d  of frame  12  includes one or more mounting holes  24 , which preferably are internally threaded. The holes  24  are adapted to threadably mate with a threaded shaft  26  of fixation elements  22 . Although shown as being substantially square or rectangular, it is understood that opposing sides  12   a ,  12   b ,  12   c ,  12   d  that form frame  12  need not be parallel. Thus, the frame may be in the form of a circle or an oval, or it may be substantially O-shaped or D-shaped. 
     In one embodiment, the mounting holes  24  formed in sides  12   b  and  12   d  are aligned so as to be parallel to the direction in which the sides  12   b  and  12   d  extend, enabling retractor blades  16  to be positioned at various locations along the length of sides  12   b ,  12   d  (in the x direction, as shown in FIG.  2 B). As shown best in FIG. 2B, sides  12   a  and  12   c  each include flanges  28  that extend perpendicular to sides  12   a ,  12   c , on either side of sides  12   a ,  12   c . In this embodiment mounting holes  24  are disposed in flanges  28  such that the holes extend in a direction substantially parallel to the holes formed in sides  12   b ,  12   d . The presence of the flange structure enables retractor blades  18  to be mounted securely on the frame  12  and to be positioned at various locations in the x direction (FIG.  2 B). Optionally, additional mounting holes  24   a  may be present on sides  12   a ,  12   c , extending in a direction parallel to that in which sides  12   a ,  12   c  are oriented. The presence of mounting holes  24   a  allows the blades  16 ,  18  to be located in various positions in the y direction. One of ordinary skill in the art will readily appreciate that the common retractor blades  16  and retractor blades  18  each may be mounted on sides  12   a ,  12   b ,  12   c , or  12   d.    
     The dimensions of frame  12  may vary as required by different surgical applications. The number and size of mounting holes  24  may vary as well. In one embodiment, the sides  12   a - 12   d  have a length and a range of about 100 to 500 mm. In one embodiment, the frame  12  may be square or rectangular, and the dimensions of central opening  21  are in the range of about 80 by 150 mm to about 300 by 450 mm. Flanges  28  preferably extend a distance L f  of about 20 to 60 mm. The number of mounting holes  24  present in the sides and in the flanges  28  may vary as well. Generally, about 5-10 holes  24  and  24   a  are present in each of the sides while about 3-6 holes  24  are formed in the flanges  28 . In one embodiment mounting holes may be placed entirely around the frame. 
     FIGS. 3A,  3 B, and  5  illustrate an alternative embodiment in which frame  12 ′ is a three-sided member, which can be characterized as being substantially C-shaped. As illustrated, frame  12 ′ has a long side  12   a ′ and opposed shorter sides  12   b ′ and  12   c ′. The long side  12   a ′ preferably includes a number of mounting holes  24 ′ that are oriented in a direction parallel to the side  12   a ′. The shorter sides  12   b ′,  12   c  ′ each include flanges  28 ′ that extend in a direction parallel to side  12   a ′. The flanges  28 ′ preferably include a number of holes  24 ′ that are oriented in a direction parallel to the holes formed in side  12   a′.    
     One of ordinary skill in the art will appreciate that the dimensions of frame  12 ′ may vary as well. The length of side  12   a ′ is in the range of about 150 to 500 mm while the length of sides  12   b ′,  12   c ′ is in the range of about 100 to 300 mm. The length L f  of flanges  28 ′ may be similar to that of flanges  28 . In addition, one of ordinary skill in the art will appreciate that flanges  28 ′ may include the same as or a different number of holes as are present in flanges  28 . 
     The common retractor blades  16  may be of a type that includes a mounting section  41  and a tissue-retracting section  43 . The mounting section is substantially horizontally oriented and the tissue-retracting section  32  is angularly oriented with respect to the mounting section. The tissue-retracting section  32  may be oriented at an angle of about 45° to 135° with respect to the mounting section, and preferably at an angle of about 90°. The mounting section  30  further includes a slot  34  having screw nesting positions  36  as will be described below with respect to retractor blade  18 . As described above, the orientation of the holes on sides  12   b  and  12   d  (assuming one opts to mount blades  16  on sides  12   b  and  12   d ) allows blades  16  to be mounted in various locations in the x direction. The position of blades  16  in the y direction can be controlled by the positioning of the screw nesting positions  36  of slot  34  with respect to fastening element  22 . 
     The fixation elements  22  are used to secure the mounting portion  18  of a blade  16 ,  18  to the frame  12 . For purposes of illustration, the fixation elements  22  are shown as thumb screws, having a head  27  and a shaft  26 . Preferably, the shaft  26  has external threads  29 , enabling the fixation element to mate with internal threads  31  formed in mounting holes  24 ,  24   a . One of ordinary skill in the art will understand that the shaft  26  of the fixation element must be appropriately sized to fit within the mounting holes  24 . 
     The retractor blades  18  of the present invention include features that allow tissue to be effectively retracted while increasing the surgeon&#39;s visual and physical access to the surgical site. With reference to FIGS. 6A-7, the blades  18  have a mounting portion  38  which, for reference purposes, is substantially horizontally oriented, and an adjacent tissue-retracting portion  40 . The mounting portion  38  includes an elongate slot  34 . In one embodiment, the elongate slot  34  has a scalloped perimeter that defines multiple screw seating positions  36 . That is, as is best shown in FIGS. 6B and 6C, the slot  34  includes multiple adjacent screw seating positions  36   a ,  36   b ,  36   c . 
     The tissue-retracting portion  40  of blade  18  includes a first section  42  that is coplanar with the mounting portion  38  and a second section  44  that is angularly oriented with respect to the first section. An open access window  19  is formed in both the first and second sections  42 ,  44  of the tissue-retracting portion  40 . Preferably, the access window  19  is substantially centrally positioned within the first and second sections  42 ,  44 . In one embodiment at least a portion of either or both of the mounting or tissue-retracting portions  38 ,  40  is malleable to enable a surgeon to optimize the shape of the blade for the best performance in tissue retraction. Selective malleability can be achieved by material choice and/or by utilizing a thinner material in a region or regions (“bend zone”) where malleability is desired. 
     As noted above, the second section  44  of the tissue-retracting portion  40  of plate  18  is angularly oriented with respect to the first section  42 . The angle of orientation may be in the range of about 45° to 135°, and preferably this angle is about 90°. In an embodiment in which the blade is malleable, the angular orientation may be selectively altered by a surgeon. 
     The access window  19  spans both the first and second sections  42 ,  44  of the tissue-retracting portion  40  and thus is three dimensional, as shown in FIG.  7 . The access window  19  can be characterized as being substantially rectangular in shape, having both a generally horizontal (formed in the first section  42 ) and a generally vertical portion (formed in the second section  44 ). 
     One of ordinary skill in the art will appreciate that the dimensions of the retractor blade  18  may vary upon the desired surgical applications. Referring to FIGS. 6A-6C, the length of a horizontally extending portion L H  of the blade  18  is in the range of about 40 to 300 mm while the length of a vertically extending section L v  is in the range of about 15 to 100 mm. The length of the tissue retracting portion is in the range of about 20 to 200 mm. The width of the blade at a widest section (W 2 ) may be in the range of about 30 to 200 mm. As illustrated, one segment of the mounting portion  38  of the blade  18  may be slightly narrower than the width W 2 . This width dimension (W 1 ) is in the range of about 10 to 100 mm and extends over a majority of the mounting portion  38  of the blade. The length of the narrower segment of the mounting portion, defined by L H1  in FIG. 6A, is in the range of about 20 to 250 mm. 
     As noted above, the slot  34  is elongate and generally has a length (L s ) in the range of about 20 to 200 mm. The width of the slot (W s ) is preferably in the range of about 3 to 10 mm. 
     The access window  19  preferably has a width (W w ) in the range of about 5 to 90 mm. The length of the access window in the first section  42  of the tissue retraction portion  40  (L w1 ) is in the range of about 15 to 195 mm while the length (L w2 ) of the access window in the second section  44  of the tissue retraction portion  40  is in the range of about 40 to 300 mm. The length (L v ) of the second section  44  of the tissue-retracting portion  40  is about 20 to 250 mm. 
     FIG. 7 schematically illustrates an advantage of the retractor blade  18  of the present invention. While the blade  18  is effective, in concert with other blades, to retract tissue, visual and physical access by the surgeon is enhanced as a result of the access window  19 . That is, a surgical tool  46  is able to be passed through the access window to a desired location, or to further retract or otherwise manipulate tissue that is adjacent to the access window. 
     One of ordinary skill in the art will appreciate that the components of the retractor system of the present invention can be made from one or more biocompatible metals or metal alloys, or polymeric materials. An exemplary metal is titanium, while exemplary alloys include, but are not limited to, stainless steel (e.g., 316 LVM stainless steel), a titanium-vanadium-aluminum alloy (e.g., an alloy having about 90% by weight titanium, about 6% by weight aluminum, and about 4% by weight vanadium), a cobalt-chromium alloy, a cobalt-chromium-molybdenum alloy and a cobalt-nickel-chromium-molybdenum alloy. Biocompatible polymeric materials are also included within the instant invention. Examples of such polymers include nylons, polyetherether ketones (PEEK), polyetheraryl ketones (PEAK), and polysulfones. 
     One of ordinary skill in the art will appreciate further features and advantages of the invention based on the above-described embodiments. Accordingly, the invention is not limited by what has been particularly shown and described, except as indicated by the appended claims. Although dimensions are provided, it is understood that these dimensions may vary and are provided for purposes of exemplification. All patents and publications cited herein are expressly incorporated by reference in their entirety.