Abstract:
Surgical methods providing access to delicate tissue, such as brain tissue or breast tissue, through a transcutaneous incision. A method may include making an incision adjacent a region containing delicate tissue, and providing a surgical assembly having: a retractor having a hollow sleeve extending from a proximal end to a distal end, and an introducer having a proximal end installed within the hollow sleeve and a distal end extending beyond the distal retractor end. The surgical assembly is advanced into the region containing delicate tissue, and the distal introducer end gently displaces the delicate tissue as the surgical assembly is advanced to thereby avoid damage to the delicate tissue. The introducer is removed from the retractor to leave the distal retractor end at a surgical site located in the physical region containing delicate tissue. One or more surgical instruments are then used through the hollow sleeve.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a continuation of U.S. patent application Ser. No. 11/155,175 filed Jun. 17, 2005 now abandoned, which application is incorporated herein by reference in its entirety. 
    
    
     FIELD OF INVENTION 
     This disclosure relates to surgical access instruments for use with delicate tissues and methods of use. 
     BACKGROUND 
     Traditional surgical brain retractors are thin, firm or malleable bands of steel or other metal alloys, with abrupt or well-defined edges and have limited surface areas. The common structural form of the standard retractors is a simple strip of metal consisting of a metal strip which can be bent by hand and the surface of which typically is used to pull apart or spread delicate tissue. The strip typically is clearly outlined on the brain after a few minutes, and particularly noticeable are the pressure marks from the lateral spatula edges which indicate a high local compression stress. These traditional retractors can be introduced into the tissue of the brain or along brain surfaces, and then pulled with force to either separate or elevate the brain tissue during surgery. This method allows the target area to be illuminated and visualized in order to perform the surgical procedure. However, brain tissue is quite soft and delicate, particularly after trauma, loss of blood supply, or in the presence of brain edema. The brain tissue is a gel-like substance that can be easily damaged, and a complication known as “retraction injury” can occur, sometimes resulting in compromised brain function. The brain tissues can be torn by the relatively sharp edges of these retractors, and/or the retracted brain can lose blood supply when the local pressure beneath the retractor is greater than venous pressure. The result can be ischemic changes in the underlying brain and/or the more serious complication of venous brain infarction. 
     The combination factors including the softness of the brain tissue, and the effects of sharp, blunt edges and limited surface area of traditional metal band retractor also results in limited visualization of the surgical target area. The brain tends to extend beyond or “droop” around the edges of the retractor, limiting the area necessary for lighting and reducing overall visibility. 
     Furthermore, the amount of local pressure exerted by the retractor on the brain tissue must be limited to avoid injury, which may impede the surgeon&#39;s ability to safely gain enough visualization area. Oftentimes, the surgeon will resort to the strategy of exposing far more of the brain tissue than is necessary or desirable to open the area around the brain widely enough so as to limit the amount of local retraction pressure. This method is undesirable, as compared to a less invasive approach, for both the patient and surgeon. 
     It would be advantageous to provide a surgical instrument assembly that safely addresses the shortcomings of the presently-known instruments. 
     EXEMPLARY OBJECTS OF THE INVENTION 
     Exemplary objects and design principles of the surgical access instrument assemblies of this invention are as follows:
         (1) to maximize surface area of the retractor, so as to distribute pressure evenly and minimize effective local retraction pressure or specific high pressure points;   (2) to enable integration with stereotactic neuro-navigation computer guidance system;   (3) to reduce the need to “pull” on a brain retractor, to obviate the possibility of accidental over-retraction and thereby avoid brain damage;   (4) to allow for binocular vision with the utilization of elliptical architecture;   (5) to allow for maximal lighting access clearance and target tissue visualization;   (6) to allow for minimization of brain disruption by limiting the corticotomy via use of a small elliptical window for the transcortical introducer;   (7) to allow for minimization of brain disruption with the utilization of tapered forward edges;   (8) to enable stable retraction fixation to avoid accidental retractor displacement;   (9) to provide retractors which are of lightweight materials to allow for ease of manipulation; and/or,   (10) to provide transparent retractors to allow for direct visualization of underlying brain tissue.       

     Other objects also may become apparent from the following description of the present invention. 
     SUMMARY OF THE INVENTION 
     In keeping with these objects and others which may become apparent, the present invention is directed toward an access assembly for surgical instruments. Non-limiting, exemplary embodiments of the access assembly are described in this Summary of the Invention and elsewhere herein. The access assembly for surgical instruments includes two principal components. One component is an internal instrument access assembly and the other is an external instrument access assembly. The internal instrument access assembly is designed to enter the brain to gain access to deeper internal brain structures. The external instrument access assembly is designed to separate or elevate the surfaces of the brain to gain access to external structures along, around or beneath the brain. Both will be produced in varying sizes according to the needs of individual operations. The materials for these retractors will be composed of transparent biocompatible lightweight plastic. Each of the instrument assemblies includes two separate parts: a retractor that also functions as a working channel, and a compatible introducer. 
     The internal instrument assembly is a wedge retractor introducer, which preferably includes a hollow wedge formed by all or part of a closed curve in cross section, such as an elliptical rounded wedge or an arch shaped wedge. It includes a hollow brain access working channel that can be fixed in space to a standard neurosurgical fixation cable device. First, a protruding introducer element, having a length greater than the length of the hollow working channel, is introduced into the working channel. Its distal smooth and relatively soft tapered end works to spread apart the brain hemispheres or other portions of delicate brain tissue. When the working channel is introduced, the introducer is removed, leaving the hollow working channel for the surgeon to access to the target tissues. Variations will include length (Z axis), and width and height (X and Y axes) of the elliptical working channel and introducer. 
     A fixation portion is designed to be attached to a standard neurosurgical armature fixation device. 
     The external surgical access instrument assembly is characterized by an arched hemi-elliptical architecture, wider along the base (X axis) than tall (Y axis). It is smooth, tapered at the leading edge, has a handle fixation portion that is o the same design as that of the internal instrument assembly, and is designed to be attached to a standard neurosurgical armature fixation device. Variations will be in length (Z axis) as well in X and Y axes. 
     Therefore, the present invention encompasses one or more surgical instrument assemblies to provide access to delicate tissue at the end of the working channel, such as brain tissue or breast tissue, through a transcutaneous incision, for a variety of reasons, such as to access a surgical site; to provide access to insert an inflatable prosthesis; or to provide access for providing an external buttress channel for supporting tissue thereon. The surgical instrument assembly includes an interleaved combination of an open sleeve hollow retractor and a tapered tipped wedge introducer. The wedge introducer is introduced into an area adjacent to the hollow sleeve. The distal tip of the wedge introducer extends beyond a distal end of the hollow retractor, forward of a distal end of said hollow retractor, so that the wedge introducer traverses the delicate tissue ahead of the distal end of the hollow retractor, guiding the hollow retractor into place in the delicate tissue. 
     When used in conjunction with working surgical instruments, the distal end of the introducer has a small opening, preferably elliptically oval, to allow for removal of small portions of tissue, to allow for caurterization and to allow for suction of tissue or fluids from a surgical site. 
     The hollow retractor may have a diameter which is a closed curve, such as an elliptical oval. In such case, a tapered tipped wedge introducer is inserted into the inside of the closed curved hollow retractor. In an alternate embodiment, the tapered tipped wedge introducer may have a diameter which is an arc, wherein the arc is a portion of a closed curve, and further wherein the tapered tipped wedge is an arch insertable into the closed curved hollow retractor. 
     When used as an external working channel, the distal end of the working channel is bell shaped, to allow for increase for increased surface area exposure. 
     The hollow retractor may alternatively also be an arc of a portion of a closed curve, also forming an arch shape. In such case, the tapered curved tipped wedge introducer may also be an arc of a portion of a closed curve, also forming an arch shape. 
     In the case where the hollow retractor and/or the tapered tipped wedge introducer has a diameter of at least one arc of a curve, they preferably can have a decreasing curved cross sectional diameter. 
     Moreover, in such case where the hollow retractor is arch shaped, as opposed to being a closed curved shape, such as being an-elliptical oval in cross section, the wedge introducer is placed adjacent to the concave inner portion of the hollow retractor. 
     If the hollow retractor is a closed curve, that is, having an elliptical oval cross section, preferably of decreasing diameter towards it distal, tissue contact edge, then the combination of the hollow retractor and wedge introducer are used to either spread apart adjacent delicate tissues, such as the left and right hemispheres of the brain, or to traverse the delicate tissue, such as brain tissue, to provide internal access to a surgical site within the delicate tissue. 
     If the hollow retractor is arch-shaped, that is, having a diameter which is an arc, namely, a portion of a closed curve, then the combination of the hollow retractor and the wedge introducer are used to provide access to a delicate tissue, where the delicate tissue is supported upon the convex outer surface of the hollow retractor, forming a support buttress, after removal of the arch-shaped wedge introducer. 
     Additionally, if the hollow retractor is also arch-shaped, that is, having a diameter which is an arc, namely, a portion of a closed curve, then additionally the combination of the hollow retractor and the wedge introducer is used to provide access to a delicate tissue, where an inflatable member, such as a breast prosthesis, is inserted into the delicate breast tissue and inflated, after removal of the arch-shaped wedge introducer from the hollow arched retractor. 
     The tipped wedge introducer has an exterior surface corresponding to an interior surface of the hollow sleeve and the closed end tipped wedge introducer may have a diameter with an arc of a decreasing curved cross section approximating the arc of the curved cross section of the open sleeve of the retractor. 
     Preferably, the hollow retractor includes a handle or a tab that is attachable to a clamp. 
     Optionally, the hollow retractor and the tapered tipped wedge introducer include a lock temporarily locking said tapered tipped wedge introducer adjacent to the hollow retractor. 
     When the hollow retractor is elliptically oval in cross section, the closed plane curve is generated by a point moving in such a way that the sums of its distances from two fixed points is a constant, or the closed plane curve is a plane section of a circular cone that is a not perpendicular to an axis of the cone, thereby forming a planar elliptical oval slice through the cone. 
     Moreover, the hollow retractor may be flared at a proximal end. Additionally, where a base of a handle is attached, the handle may merge in a cascading shape, interrupting the continuous curve of the proximal end of the hollow retractor. Such a cascading dip in structure allows for easier finger access into the working channel of the hollow retractor. 
     Additionally, the hollow retractor may have a changing cross section, where the cross sectional diameter of the elliptical oval is wider or narrower at selected regions of the working channel of the hollow retractor. 
    
    
     
       DESCRIPTION OF THE DRAWINGS 
       The present invention can best be understood in connection with the accompanying drawings. It is noted that the invention is not limited to the precise embodiments shown in drawings, in which: 
         FIG. 1  is a view of a patient with a retractor assembly and a buttress channel positioned adjacent to a top of the head and lower skull. 
         FIG. 2  is a perspective of retractor assembly of  FIG. 1 . 
         FIG. 3  shows exploded components of  FIG. 2 . 
         FIG. 4  is a top plan view of an introducer. 
         FIG. 5  is a proximal end view of an introducer. 
         FIG. 6  is a side sectional elevational view thereof. 
         FIG. 7  is a top plan sectional view thereof. 
         FIG. 8  is a sectional detail of a locking tab, taken from  FIG. 7 . 
         FIG. 9  is a top plan view thereof. 
         FIG. 10  is a proximal end view of the retractor. 
         FIG. 11  is a side sectional elevation thereof. 
         FIG. 12  is a top plan sectional view thereof. 
         FIG. 13  is a sectional detail view of the groove, taken from  FIG. 12 . 
         FIG. 14  is a sectional detail of locking tab and groove, taken at  14 - 14  of  FIG. 2 . 
         FIG. 15  is a proximal end view of the assembly, taken at arrow  15  in  FIG. 2 . 
         FIG. 16  is a view of the instrument assembly being inserted into the top of a skull. 
         FIG. 17  is a view of the instrument assembly spreading the brain lobes apart. 
         FIG. 18  is a view of the instrument assembly installed, taken at arrows  18 - 18  of  FIG. 17 , with an ear of introducer flexed. 
         FIG. 19  is a view of the instrument assembly with the introducer removed. 
         FIG. 20  is a view of surgical instruments within the retractor channel. 
         FIG. 21  is a diagrammatic sectional view of an embodiment which is installed transversely into tissue. 
         FIG. 22  is a view of the external instrument assembly system adjacent to the lower skull. 
         FIG. 23  is a view of the instrument assembly components of  FIG. 22  exploded. 
         FIG. 24  is a perspective view of the instrument assembly system installed in the lower skull. 
         FIG. 25  is a diagrammatic side section of installed instrument assembly, with the introducer removed. 
         FIG. 26  is a diagrammatic view of the instruments working on an external tumor. 
         FIG. 27  is a diagrammatic view of an alternative embodiment, installed through forehead. 
         FIG. 28  is a diagrammatic view of the instrument assembly installed into breast tissue. 
         FIG. 29  is a perspective exploded view of a surgical kit. 
     
    
    
     DETAILED DESCRIPTION 
     This disclosure relates to a surgical instrument assembly and system for use with delicate tissues and methods of using the instrument assembly. The instruments are designed for use during surgery on delicate tissues, such as brain and breast tissues, although they may be used in any medical context. The instrument assembly includes several portions, such as, an introducer portion, a tissue access channel retractor portion (“channel portion”) having at least one handle portion, and a stylette portion. These instrument portions are formed to maximize the surface area of the retractor, which distributes pressure approximately equally though out the surrounding tissues and minimizes effective localized retraction pressure on the tissues in contact or immediately surrounding the instrument. 
     In one embodiment, the surgical instrument assembly can be a retractor in the form of an arch or arc shape, into which an arch or arc shaped wedge introducer may be inserted for surgical access to the external portions or surfaces of the brain. 
     In another embodiment, the surgical instrument assembly can be a retractor in the form of a wedge with a tapered elliptical cross sectional shape, into which a tapered elliptical cross sectional introducer may be inserted for surgical access to the external portions or surfaces of the brain. 
     Alternatively, the external retractor and wedge introducer may be used to insert medical/cosmetic devices into or under delicate tissues. 
     The surgical instrument assembly system may also employ the external retractor as an external brain support buttress channel portion to lift the brain mass upward with respect to the cranium to provide stability and prevent the gelatinous brain materials from shifting during surgery. In the capacity of a brain support buttress channel portion (“buttress portion”) also provides improved visualization and improved access to the surgical area by lifting the brain matter upward in the cranium. 
     The formation of the instrument assembly also eliminates the need to “pull” a retractor against tissue portion to clearly visualize the surgical area by initially providing a sufficient work area via the channel retractor. The use of the tissue access channel retractor portion of the instrument assembly eliminates or greatly lowers the possibility of accidental over-retraction. By avoiding excess retraction, dainage to the surrounding tissues is also avoided, including possible brain damage. 
     While other closed curve configurations may be used, the preferably elliptical or arch shaped architecture formation of the instrument assembly portions is such that medical staff is afforded binocular vision, rather than the monocular vision typically found in similar devices. This elliptical architecture also provides far greater clearance for lighting access to illuminate the target surgical area and allows full visualization of that area. The forward edge of the channel retractor is preferably tapered to gently separate tissue to obtain a surgical area and minimizes disruption of the tissue. 
     The surgical instrument assembly system may also be useful as an inserter instrument for breast implants. 
     The dimensions of the surgical instrument assembly may vary and be modified according to an intended use. Generally, the surgical work space formed by the introducer portion  40  can have diameters of in the range of approximately 10 millimeters (“mm”) to approximately 100 mm, and more typically in the range of approximately 25 mm to approximately 75 mm in its closed configuration. The open configuration of the introducer portion  40  may extend the diameter of the distal end  42  of the introducer portion  40  several millimeters, and may generally be determined by amount of extension desired by the surgical team during use as it is introduced into the lumen  22  of the retractor  20 , and may include a flexible band portion to enhance its flexibility. The open configuration may also be determined by the overall desired circumference and diameter of the surgical instrument assembly for a particular use and may be manufactured in a variety of useful sizes to be available as is practical. The Surgical instrument assembly may be formed of any biocompatible material which will provide sufficient stability and strength necessary to provide a surgical work area. The biocompatible material may be disposable or sterilize-able for repeated use. In one embodiment, the surgical instrument assembly may be formed of a lightweight plastic material for ease of manipulation and/or the material may be transparent to allow direct visualization of underlying brain tissue thorough the instrument assembly portions. 
     The surgical instrument assembly system also enables integration with stereotactic neuro-navigation computer guidance systems to enhance visualization of the surgical area of the brain. 
       FIG. 1  illustrates in diagrammatic fashion the surgical instrument assembly system  10  adjacent a surgical aperture in the cranium of an intubated patient. An external retractor system  100  is also spaced from the lower skull, and will be described later in the specification. 
       FIG. 2  is an enlarged perspective view of the surgical instrument assembly system  10  as shown in  FIG. 1 . The instrument assembly system  10  is comprised of two components, a retractor  20 , and an introducer  40 . 
       FIG. 3  illustrates the relationship of introducer  40  to retractor  20 , prior to assembly. It is desirable that the introducer is easily fixed to and removable from the retractor both prior to and during the surgical procedure. 
     As also shown in  FIG. 3 , the surgical instrument assembly system may be formed by any method, including injection molding, as a single piece, or may be formed of two or more pieces which are permanently fixedly attached to each other. The distal end  42  of the introducer portion  40  is preferably a solid, rounded cone shape which may or may not include an opening  52  to the surrounding tissues as opposed to a cannula structure which always provides a distal opening. The distal end  42  preferably includes a gently increasing circumference  54 , which increases and expands towards the proximal end  56  of the introducer portion  40 . The introducer portion  40  has a main body  50 , and may be divided into two approximate handle halves  46 , having V-shaped cutouts  48  between the handle halves. The halves of the proximal end  56  are an integral unit, the term “halves” is used as a descriptor only and does not describe separable parts, as opposed to two disassemblable halves. The proximal end  56  may include at least one handle portion  46  which extends outwardly at an angle of approximately 90 degrees. A handle portion  46  may be useful to allow a medical team member to physically insert, manipulate or hold the handle portion  46 , or a conventional surgical fixation cable may be attached to the handle portion  46 . At least one of the handle portions  46  include at least one indentation or groove tab  44  to accept or snap into an additional portion of the surgical instrument assembly  10 . 
       FIGS. 4-8  show a variety of views of the retractor portion  20  of this disclosure, including retractor  20  having a hollow working channel  22  and handle  28 . The retractor  20  is generally formed to dimensions and shapes to coincide with the introducer portion  40  that may be slideably inserted into the brain access work channel  22  of the retractor portion  20 . The retractor portion  20  is generally shorter in length than the introducer portion  40  to allow the distal end  42  of the introducer portion  40  to interact with the surrounding tissues. As best seen in  FIGS. 6 and 7 , the retractor portion  20  is formed as a hollow elliptical rounded wedge  21  having a tapered distal leading edge  24 . The proximal edge of the retractor  20  includes a slightly rounded lip  26  and a handle portion  28 . At least one hole  30  is formed in wedge  21 , just distal of lip  26 . Hole  30  will positively align with tab  44  of introducer  40  to prevent or inhibit unnecessary movement or slipping of the instrument assembly components best seen in sectional view  FIG. 15 . The handle portion  28  allows the retractor portion  20  to be fixed in space with the use of a standard or conventional neurosurgical fixation cable device or clamp  58 . 
       FIG. 9  illustrates a side view of a retractor  20 , having a proximal lip  26  of the surgical instrument assembly and optionally having a handle portion  28  perpendicular to the proximal lip  26 ; and the hollow elliptical rounded wedge  21  portion of the retractor  20  extends to the rounded distal end  24 .  FIG. 10  is a frontal view of the retractor  20 , showing the lumen  22  and the handle portion  28 .  FIG. 11  is a cross-sectional view of the retractor  20  of the rounded shape of the retractor  20  to avoid damage to brain tissues.  FIG. 12  is a top plan view of the retractor  20 , emphasizing the groove like cut-out hole  30  which can allow the introducer  40  to integrally fit and temporarily lock/snap into hole  30 , thereby causing both the retractor  20  and introducer  40  to function as one, while desired by the medical team.  FIG. 13  is an enlarged view of the grooved hole  30 .  FIG. 14  is a cross-sectional view of the tab  44  of the introducer  40  while it is engaged within the grooved hole  30  of the retractor  20 . 
     Shown in  FIG. 15  is a proximal end view of assembled instrument where the handle portions  46  overlying lip  26  of retractor  20 , and V-shaped cutouts  48  residing in lumen  22 . Handle  28  of retractor  20  is molded integral with lip  26 , providing both rigidity and strength.  FIG. 15  also shows that where a base of handle  28  is attached to retractor  20 , handle  28  may optionally merge in a cascading shaped dip  28   a , interrupting the continuous curve of the proximal end of hollow retractor  20 . Such a cascading dip  28   a  allows for easier finger access into the working channel of hollow retractor  20 . 
       FIGS. 16-20  illustrate diagrammatically the method if installing surgical instrument assembly  10  into the aperture  12  in cranium  14 . As seen in  FIG. 16 , instrument assembly  10  is inserted into aperture  12 . Distal end  42  of introducer  40  is abutting brain tissue  60 . As instrument assembly  10  is introduced, distal end  42  of introducer  40  begins to spread tissue or lobes  62  and  64  of brain  60 , as shown in  FIG. 17 .  FIG. 18  is an elevational view of the installed surgical instrument assembly  10 , taken along arrows  18 - 18  of  FIG. 17 . Upon installation, handles  46  of introducer  40  may be flexed inward, thereby releasing the hole  30  of retractor  20  from the tab  44  of introducer  40 .  FIG. 19  illustrates introducer  40  during removal from lumen  22  of retractor  20 .  FIG. 20  shows surgical instruments  70  within lumen  22  of retractor  20 , examining brain tissue  60 . 
       FIG. 21  is a diagrammatic perspective view of an embodiment of the surgical instrument assembly  10 , adjacent an aperture  12  located at the temple region of a patient&#39;s cranium  14 . In this embodiment, the overall length of surgical instrument assembly  10  is sufficient to transversely penetrate the cranium and brain tissue  60 . Surgical instrument assembly  10  is shown installed in  FIG. 22 . 
       FIG. 23  is a perspective view of the external retracting buttress channel  100 . External buttress channel instrument assembly  100  is comprised of buttress channel component  200 , and wedge introducer component  400 . External buttress channel component  200  has a generally arched, hemi-elliptical architecture, where it is wider along the base than it is tall or high. The buttress channel component  200  includes a smooth, tapered leading edge  202 . A handle fixation member  204  is approximately perpendicular to the rounded lip  206  of the proximal end  208 . The handle member  204  may be employed as an attachment point to a standard neurosurgical armature fixation device. The external buttress channel component  200  may be used to lift, support or manipulate the brain within the skull cavity to provide additional or improved vision of the surgical area, as seen in  FIG. 24 . 
     Also seen in  FIG. 23  is the external wedge introducer portion  400  for the external buttress channel component  200 . Buttress channel  200  is designed to gain access to external structures along, around or beneath the brain by elevating the surfaces of the brain to allow access to surgical locations on or near the surface of the brain tissues. In operation, prior to insertion, introducer portion  400  is attached to buttress channel  200  such that sloping distal end  402  protrudes from the distal open end  210  of buttress channel  200 . This pushes away brain tissue at the outer brain surface  66  gently during insertion. After insertion, introducer portion  400  is withdrawn to leave a working channel of decreasing hemi-oval cross section from proximal end  208  to distal end  210 . Radial surface of buttress channel  200  supports the outer surface  66  of the brain tissue  60 , best seen in  FIG. 24 . Note that surface of wedge introducer  400  conforms to the inside of buttress channel surface; proximal end  208  and handle member  204  conform to proximal end  406  and fixation member  408  of introducer  400  respectively. Fixation member  204  of buttress channel  200  is designed to be attached to a standard neurosurgical armature fixation device. 
       FIGS. 25 and 26  are diagrammatic view of the instruments working on an external tumor, where the further surgical instruments  70  are inserting into the operating space formed by the instrument assembly system to allow the surgical team to work on the tissues as necessary. 
       FIG. 27  is a diagrammatic view of an embodiment, which may be installed through the forehead as necessary for surgical procedures.  FIG. 28  is a diagrammatic view of the instrument assembly installed into breast tissue  68 , where it may be used for insertion of implants  72  and the like. 
       FIG. 28  shows use of an arched buttress channel  200  and wedge introducer component  400  which may be used, for example, for access to brain tissue or for inserting an inflatable prosthesis into breast tissue. 
       FIG. 29  is a perspective exploded view of a surgical kit. The Kit  600  includes an injection-molded or vacuum-formed housing  602 , providing cavities  604  to receive components of the surgical instrument assembly system  10  and the external retracting buttress channel system  100 . A stylette  80  may also be included. Upon placement of all desired components within the housing  602 , the sterile kit will be sealed with a Tyvek sheet  606 . Upon removal of sheet  606  by the surgeon, the sterile components of kit  600  can be utilized and employed as required in a surgical operation. 
     In the foregoing description, certain terms and visual depictions are used to illustrate the preferred embodiment. However, no unnecessary limitations are to be construed by the terms used or illustrations depicted, beyond what is shown in the prior art, since the terms and illustrations are exemplary only, and are not meant to limit the scope of the present invention. 
     It is further known that other modifications may be made to the present invention, without departing the scope of the invention, as noted in the appended Claims.