Abstract:
A surgical retractor liner and integral drape suitable for inserting in an incision and adjusting in place to prevent cross-contamination during surgery between the incised cavity and the surrounding skin of the patient. In one embodiment, a flexible elastic liner impervious to microorganisms has resilient inner and outer rings at opposite ends for holding the liner firmly in the incision. The outer ring is rolled down over itself drawing the liner taut and contiguous in the incision. In another embodiment, a skirt is sealingly joined at the outer ring and tapers outwardly and sealingly joins to a drape around a central aperture therein. The inner ring is inserted and expanded against the inner edge of the incision, and the outer ring is rolled down over the liner and skirt to draw the liner taut in the incision and to retract the sides of the incision while positively anchoring the drape in place around the area of the incision. In another embodiment, a lengthwise incrementally and automatically adjustable wound protector and retractor is provided.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
     This application is a division of co-pending application Ser. No. 09/463,252 filed on Jan. 21, 2000, which, in turn, is a 371 of PCT/US97/12800 which was filed on Jul. 21, 1997. 
    
    
     FIELD OF THE INVENTION 
     The present invention relates generally to improvements in surgical devices, and more particularly to an improved adjustable retractor, and a retractor with a liner and integral drape therefor for preventing contamination of incised cavity walls of various thicknesses during surgery. 
     BACKGROUND OF THE INVENTION 
     The sides of an open incision, as well as matter such as body parts and fluids passing through the incision during surgery, are inherently susceptible to cross-contamination by infectious microorganisms or like matter. Therefore, extreme care is required to insure that any exposed fluids or tissues are completely isolated from each other. 
     Various designs have been proposed and utilized to prevent transmission of indigenous and exogenous contaminants to healthy viscera from infectious tissues or fluids. U.S. Pat. No. 5,524,644 by Berwyn M. Crook, filed Jun. 9, 1995, describes an incision liner and retractor device which can be installed in an incision, incrementally adjusted in place to form-fit a wide range of cavity wall thicknesses, and retract the sides of the incision apart for better access to the abdominal cavity. It employs a flexible impermeable liner of pliable plastic material with opposite ends terminating at inner and outer resilient O-rings. The inner O-ring is inserted in the cavity by squeezing it through the incision and allowing it to expand around the inner edge of the incision. The outer O-ring is then rolled down over the portion of the liner extending out of the incision until it is tight against the outer rim of the incision and the remaining portion is drawn taut and contiguous with the incision sides. The outer O-ring is generally oblong in cross-section to provide a positive gripping surface for the fingers to roll the outer O-ring more easily, especially when the liner or the surgeon&#39;s gloves are slippery. 
     In many instances, a surgical drape may be first placed over the patient&#39;s body before the incision liner and retractor device is installed. This combination further reduces the risk of cross-contamination between the open cavity and the skin around the incision, especially if an organ is brought outside the abdominal cavity to perform surgery on it. However, since the liner and drape are not integrally connected, there is no assurance that the drape may not slide from beneath the outer O-ring and leave the patient&#39;s skin exposed in a most vulnerable region immediately adjacent to the incision. 
     Some prior art surgical protectors address this problem to a limited degree. For instance, U.S. Pat. No. 3,397,692 to Creager, Jr. et al. discloses an incised surgical device in which a resilient ring cemented around the rim of a central aperture in a drape is squeezed together and expanded in the cavity to grip the incised edge of the peritoneum. The drape is bunched together where it passes through the incision and then spreads out over the body surface in radially diminishing wrinkles. U.S. Pat. No. 4,188,945 to Wenander similarly provides a surgical cloth with a semi-rigid thread hemmed in around a central aperture. A portion of the cloth around the aperture is gathered together and inserted in an incision, and then enlarged under the incision edge by increasing the length of thread around the aperture. Like the surgical device of Creager, Jr. et al., a wrinkled surface is created in the incision and around the operating site. Consequently, neither device provides a relatively smooth surface in the incision and around the wound where extracted viscera may be placed nor positive retraction of the sides of the incision. In addition, there is no means for preventing external portions of the drape from slipping in and out of the incision with movement of the surgeon&#39;s hand. 
     OBJECTS OF THE INVENTION 
     Accordingly, it is an object of the present invention to provide an improved surgical retractor liner and integral drape which prevent exposure to cross-contamination by infectious fluids and solids between an incised cavity and the skin around the incision. 
     Another object of the invention is to provide a surgical retractor liner and integral drape assembly which interfaces smoothly and contiguously with the sides of an incision and with the skin around the incision. 
     Still another object of the invention is to provide a retractor liner with integral drape which can be easily installed and adjusted in place to fit a wide range of cavity wall thicknesses. 
     A further object is to provide a retractor liner which will positively insulate an incision from exposure to indigenous and exogenous contaminants and positively retract the sides of the incision for a wider opening to the cavity. 
     A further object of the present invention to provide a relatively low cost surgical retractor liner of simplified design which can be easily installed in a wound and adjusted in place to form fit a wide range of cavity wall thicknesses for protection against harmful contaminants. 
     SUMMARY OF THE INVENTION 
     These and other objects and aspects of the invention are accomplished in one embodiment by a surgical retractor liner and integral drape which can be inserted in an incision and incrementally adjusted tightly in place in the cavity wall and on the surrounding skin to prevent cross-contamination with body fluids and solids during surgery. It includes a flexible plastic film retractor liner impervious to microorganisms with opposite ends terminating at inner and outer resilient O-rings. The inner O-ring is installed in the incision by squeezing opposite sides together, inserting it through the incision and allowing it to expand around the inner edge of the incision. The length of the retractor liner is selected to allow a portion to extend out of the incision for rolling down until it is tight against the outer edge of the incision and retracts the sides of the incision for widening the opening. A flexible plastic film skirt fixed at one end around the outer O-ring, and coaxial with the retractor liner, tapers outwardly toward the inner O-ring with the other end sealingly joining the rim of a centrally located aperture in a flexible drape. The extended length of the skirt is at least as long as the portion of the retractor liner fully extending out of the incision when the inner O-ring is expanded against the inner edge. This assures that the drape completely adheres to the surface around the incision and remains fixed in place by the retractor liner and by adhesive patches fixed to the drape. The size of the drape is sufficient to cover the area around the operating site and to prevent it from exposure to any contaminating fluids and tissue. 
     In another embodiment, the retractor liner comprises a flexible liner of thin substantially elastic material, separate from the drape, secured at opposite open ends around resilient inner and outer O-rings. 
     In both embodiments, the outer O-ring in cross-section is generally circular with opposed flat sides in planes generally transverse to the extended length of the liner for restoring the outer O-ring to its preformed configuration when turned about the circumferential axis of rotation of the ring. The flat sides also provide gripping surfaces for manually turning the outer O-ring with greater ease, especially when the liner or the surgeon&#39;s gloves are slippery. The retractor liner may be constructed in a single liner length with different circumferences for accommodating a wide range of incision sizes and cavity wall thicknesses. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The foregoing and other objects, features, and advantages of the invention will become more apparent from the following description of the preferred embodiments when taken in conjunction with the accompanying drawings wherein: 
     FIG. 1 represents a perspective top view of one embodiment of a surgical retractor liner and integral drape device according to the invention; 
     FIG. 2 is a side view partially in cross-section of a portion of the embodiment of FIG. 1; 
     FIG. 3 is an enlargement in cross section of an upper portion of the embodiment shown in FIGS. 1 and 2; 
     FIG. 4 is a view in radial cross section of an alternate embodiment of an O-ring for use in the upper portion of the assembly shown in FIG. 3; and 
     FIGS. 5A and 5B are schematic illustrations of the device in two stages of installation in an incision; 
     FIG. 6 is an isometric view of another embodiment of a retractor liner according to the invention, in a fully extended state and with portions cut away; 
     FIG. 7 is a view in longitudinal cross-section of an outer end of the retractor liner of FIG. 6; 
     FIGS. 8A and 8B is a schematic representation in longitudinal cross-section of the retractor liner of FIG. 6 partially installed in a surgical wound; and 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     Referring now to the drawings wherein like reference characters designate like or corresponding parts throughout the several views, there is shown in FIG. 1 a surgical retractor liner and integral drape device  10  comprising an incision retractor liner  12  of uniform circumference along its length coaxially extending through a skirt  14  and a central aperture  16   a  in a drape  16 . 
     As best seen in FIG. 2, retractor liner  12  and skirt  14  have adjacent upper ends which wrap around an outer O-ring  18  and overlap at annular edges  12   a  and  14   a  (FIG. 3) and seal to each other and to the outer side skirt  14 . A lower end portion of retractor liner  12  wraps around an inner O-ring  20  and overlaps at an annular edge  12   b  and seals to the outer side of retractor liner  12 ; whereas a lower end of skirt  14  is sealed around the perimeter of aperture  16   a . Retractor liner  12  is essentially uniform in circumference along a central longitudinal axis defined by the extended length of the liner. Skirt  14  is coaxial with retractor liner  12  and tapers outwardly to aperture  16   a.    
     Outer O-ring  8  is generally oblate in cross-section with opposed upper and lower flat chordal sides  18   a  and lab substantially normal to the extended length of retractor liner  12 . Sides  18   a  and  18   b  are located equidistant from, and on opposite sides of, the centroid of the radial cross-section through O-ring  18 . The oblate shape provides an over-center snap action when O-ring  18  is rolled about itself onto retractor liner  12  and skirt  14  for incrementally shortening the upper ends and for resisting unrolling after being shortened. 
     Inner O-ring  20  is entirely circular in cross-section, but may have a similar cross-section as O-ring  18  for incrementally shortening the lower end of retractor liner  12 . 
     FIG. 4 illustrates in radial cross-section an alternate embodiment of an outer O-ring  18 . The upper and lower sides  18   a  and  18   b  taper outwardly from opposite sides of a plane normal to the extended length of liner  12  thereby allowing O-ring  18  to be turned with less resistance around its annular axis due to the lesser mass near the inner circumference O-ring  18 . This structure is particularly desirable for large diameter rings having relatively large diameter cross-sections. 
     The materials for making assembly  10  are selected to insure stability when installed. One preferred material for retractor liner  12 , skirt  14  and drape  16  is a substantially inelastic heat-sealable 3-mil polyolefin plastic film, such as Saranex™ film 2050 by The Dow Chemical Company. Another preferred material for liner  12  and skirt  14  is a substantially elastic heat-sealable 2-mil polyurethane film, such as Dureflex® PT6100S by Deerfield Urethane, Inc. 
     The polyurethane material has been found to provide certain advantages not available with the Saranex™ polyolefin material. For instance, the elastic polyurethane material takes up any lengthwise adjustment which cannot be fully accommodated by the incremental adjustments made by rolling the O-ring  18 ′. In addition, the elastic polyurethane provides a better retraction function along the edges of the incised wound. This is believed due, at least in part, to the better wound edge margin gripping action resulting from the axial take-up of the elastic polyurethane. 
     The difference between the non-elastic polyolefin material and the elastic polyurethane may be seen from a test wherein five 1″×3″ specimens of each of these materials were stretch tested at room temperature (+75° F.) and permanent deformation (deflection) calculated from its load vs. displacement curve. The average deflection of the polyolefin film was approximately 0.354 inch/inch, while the polyurethane specimen deflection averaged approximately 0.167 inch/inch. 
     O-rings  18  and  20  are preferably preformed of an elastomeric medical-grade polyurethane of sufficient hardness to retain the rings expanded in place around the inner and outer rims of the incision. The O-ring material must be compliant enough to allow the fingers to turn the outer O-ring  18  over 180° around its annular axis from the preformed configuration. They may be color-coded with different colors, such as white and blue, for easier recognition of the correct O-ring to be inserted in an incision. 
     Drape  16  may be adhered directly to the skin of the patient or to an underlying drape by an adhesive spread over the underside of the drape, or by adhesive patches  22  at selected locations on the underside of the drape. The size of drape  16  is selected to provide effective protection from exposure to infectious fluids and tissue in the vicinity of the incision. 
     The length of a fully extended retractor liner  12  is typically around 150 mm to accommodate most wall thicknesses at the incision. An assortment of liner and O-ring diameters are provided to accommodate different lengths of incisions, and the personal preference of the surgeon. U.S. Pat. No. 5,524,644, supra, discloses a table of liner and O-ring diameters available for different incision lengths, and its disclosure is incorporated by reference herein. The urethane O-rings are typically in the range of 50-90 Shore A durometers. 
     The diameter of an upper length of skirt  14 , in a relaxed state before stretching around O-ring  18  and sealing it at edge  14   a , corresponds substantially to the diameter of retractor liner  12 . The remaining lower portion tapers outwardly to the diameter of aperture  16   a  which is slightly larger than the diameter of retractor liner  12  to allow clearance for retractor liner  12  to be stretched into contact with the outer rim of the incision. The length of skirt  14  must not be shorter than retractor liner  12  by an amount greater than the thickness of the wall at the incision. If the difference were greater, the drape will not adhere completely to the skin immediately adjacent to the incision. Of course, if the difference is less than the wall thickness, the lower end of skirt  14  will merely bunch up around the uninserted portion of retractor liner  12  and roll onto O-ring  18  but still provide a satisfactory seal. Typically, the thickness of abdominal walls ranges between 25 mm and 75 mm. Therefore, for an overall liner length of 150 mm, an effective skirt length should not be shorter by more than 25 mm, namely an overall length of 135 mm. 
     A typical installation of the retractor liner and integral drape assembly  10  is illustrated in two stages in FIGS. 5A and 5B. In FIG. 5 a , retractor liner  12  is inserted into an incision in the abdominal wall A with the inner O-ring  20  expanded against the inner rim of the incision and drape  16  adhered to the skin, or to an underlying drape not shown. In this installation skirt  14  is shorter than retractor liner  12  by a difference slightly less than the thickness of the abdomen wall, thereby causing skirt  14  to bunch up around fully extended retractor liner  12 . In FIG. 5B, the upper end of the assembly containing O-ring  18  is rolled down over the outside of skirt  14 , abuts the top of drape  16  with skirt  14  drawn taut against the incision, and retracts the sides of the incision to widen the opening. Drape  16  is thusly positively anchored against slipping out from under the rolled down portions of liner  12  and skirt  14 . 
     Referring now to FIG. 6, an adjustable retractor device  110  includes a thin relatively elastic liner  112 , uniform circumference along its length and impervious to solids and fluids containing bacteria and other harmful contaminants. 
     As best seen in FIG. 7, the upper end portion  112   a  of the liner  112  wraps around outer O-ring  118  and terminates in an annular edge portion  112   c  sealed around the outer side of liner  112 . At least one O-ring, such as the O-ring  118 , is generally oblate in cross-section having opposed flat chordal side surfaces  118   a  and  118   b  which are transverse, i.e. substantially normal, to the liner central longitudinal axis defined by the extended length of liner  112 , as shown in FIGS. 6-8 b . As shown, the chordal surfaces  118   a  and  118   b  are located equidistant from, and on opposite sides of, the centroid of the cross-section. The surfaces  118   a  and  118   b  provide surface means for purposes to be described. 
     Inner O-ring  120  is secured to lower end portion  112   b  in the same manner as O-ring  118 , except the configuration in cross section is entirely circular. If desired, both O-rings may have the same cross-sectional shape as O-ring  118  to provide reversibility to the retractor liner device  110 . 
     The oblate shape of the O-ring  118  provides stability in a plane perpendicular to the longitudinal axis of the liner  112  and provides an over center snap action when rolled about itself and the liner, thereby providing incremental shortening in predetermined increments and resistance to lengthening after shortening. 
     The materials and dimensions of adjustable surgical device  10  are selected to ensure stability when installed. A preferred elastic material suitable for liner  112  is a 2-mil polyurethane film, such as Dureflex® PT61005 supra. It is produced in seamless tubular form or by a flat sheet in a cylindrical form with the meeting margins along the side overlapped and sealed. A nominal liner length suitable for minimally invasive surgery is typically around 150 mm. Liner diameters will vary according to wound length as will be discussed. 
     Outer and inner O-rings  118  and  120  are preferably preformed of an elastomeric medical grade material of sufficient hardness to retain O-rings  118  and  120  expanded in place around the inner and outer edges of the wound. Like O-ring  18 , the material must be compliant enough to allow O-ring  118  to be turned by the fingers over 180 degrees around its annular axis from the preformed configuration. Urethane is therefore the preferred elastomeric material. When the O-rings are of different configurations, the O-rings are preferably color-coded with different colors, such as white and blue, for aiding in recognizing the correct end of the protector to be inserted in the wound. 
     The inside circumferences of O-rings  118  and  120  generally correspond to the outside circumference of liner  112 . By way of example, a urethane O-ring  118  for use with a liner 110 mm (4.33 inches) in diameter has a diameter across the transverse cross section of about 7.94 mm ({fraction (5/16)} inch) with a distance between parallel flat sides  118   a  and  118   b  of approximately 6.10 mm (0.240 inch). O-ring  120  has a diameter of its circular cross-section of about 7.94 mm ({fraction (5/16)} inch). Of course, the sizes of the O-rings and liners will vary according to wound size and wound wall thickness, and the personal preference of the surgeon will affect the choice of size for a particular surgical procedure. 
     The following table sets forth a preferred relation between incision length and liner and O-ring and liner diameters. It also sets forth the preferred cross-sectional diameters for each O-ring, it being understood that O-ring  18  has opposed flats and is, therefore, oblate and not circular in cross-section. 
     
       
         
               
               
               
             
               
               
               
             
           
               
                   
               
               
                   
                   
                 O-Ring 
               
               
                 Incision 
                 Liner Diameter 
                 Cross Sectional 
               
               
                 Length (mm) 
                 (mm) 
                 Diameter (mm) 
               
               
                   
               
             
             
               
                   
               
             
          
           
               
                 10 
                 30 
                 5.15 
               
               
                 20 
                 30 
                 5.15 
               
               
                 30 
                 60 
                 7.13 
               
               
                 40 
                 60 
                 7.13 
               
               
                 50 
                 80 
                 7.52 
               
               
                 60 
                 80 
                 7.52 
               
               
                 70 
                 110 
                 7.92 
               
               
                 80 
                 110 
                 7.92 
               
               
                 90 
                 110 
                 7.94 
               
               
                 100 
                 130 
                 9.53 
               
               
                 110 
                 130 
                 9.53 
               
               
                 120 
                 150 
                 11.11 
               
               
                 130 
                 150 
                 11.11 
               
               
                 140 
                 170 
                 12.70 
               
               
                 150 
                 170 
                 12.70 
               
               
                 160 
                 190 
                 14.29 
               
               
                 170 
                 190 
                 14.29 
               
               
                 180 
                 210 
                 15.88 
               
               
                 190 
                 210 
                 15.88 
               
               
                 200 
                 230 
                 15.88 
               
               
                   
               
             
          
         
       
     
     The durometers of the O-rings set forth in the above table should be in a range of 50 to 90 Shore A. The preferred material is urethane, but silicone could be used with some loss of stability after installation and adjustment. The best stability is achieved by using a material having a high modulus of elasticity with a ring, as manufactured; having a minimum of residual stresses and strains. The size of the flats affects both gripability for adjustment and stability after adjustment, since the larger the size of flats for a given O-ring cross-sectional diameter, the less stability that exists. By way of example, a preferred flat width for an O-ring having a cross-sectional diameter of 7.94 mm ({fraction (5/16)} inch) is 6.10 mm (0.240 inches). It is expected that with increasing diameters each flat width should increase proportionately based on a formula: W=xD where W is the width of the flat; D is the diametrical cross-section of the O-ring; and x is a constant equal to 0.85 for a urethane ring having a hardness within the ranges stated. 
     In using the adjustable surgical device in a minimally invasive abdominal surgical procedure, the abdomen is routinely prepared with antiseptics and dried; the site for the incision is traced on the abdomen and covered with a surgical drape; and a muscle-split is made at the site through the peritoneum. As illustrated in FIGS. 8A and 8B, retractor and liner  110  is placed in wound W 1  by squeezing inner O-ring  120  into a tight oblong shape and inserting it lengthwise through the incision and letting it expand inside the peritoneum around the inner edge of the wound. Outer end portion  112   a  is gripped by the thumb and fingers at flat sides  118   a  and  118   b  of outer ring  18  (FIG. 7) and turned outwardly, in opposite directions shown by arrows A, rolling liner  112  on the O-ring until it abuts the outer edge of the wound W 1  as shown in FIG.  8 B. However, as a result of the elasticity of the liner material, any lengthwise adjustment not accommodated by the incremental. adjustments causes the part of liner  112  in the wound between O-rings  118  and  120  to be thereby drawn into contiguous contact with the edge margins of wound W 1  and hence with the wound walls to provide a self-retaining protective barrier during surgery which is impervious to contaminating solids and fluids. If desired, the protector  10  can also be pre-adjusted prior to insertion, or partially pre-adjusted. 
     Some of the many advantages and novel features of the invention should now be readilapparent. For example, the invention provides an improved liner and drape device which prevents exposure between an incised cavity and the skin around the incision to cross-contamination by infectious fluids and tissue. The assembly is positively anchored in place around the operating site by the installed liner, smoothly interfaces against the sides of the incision and the surrounding skin, and retracts the sides of the incision for a wider opening. It can be easily installed in an incision and adjusted in place to fit a wide range of cavity wall thicknesses as well as provide positive insulation of an incision and surrounding skin from indigenous and exogenous contaminants. 
     A relatively simple and inexpensive surgical retractor liner is provided for protecting wounds from exposure to contamination. It can be quickly and easily installed in a wound and adjusted in place to form-fit a wide range of cavity wall thicknesses, and it stays in place after insertion. A fewer number of combinations of sizes of protectors are needed to accommodate a variety of incision sizes and cavity wall thicknesses. 
     Of course, it will be understood that various changes in the details, materials, steps and arrangement of parts, which have been herein described and illustrated in order to explain the nature of the invention, may be made by those skilled in the art within the principle and scope of the invention as expressed in the appended claims.