Abstract:
An intra-corporeal surgical retractor for holding tissues and organs in place is provided, including a sealed container, made from a flexible material, having an interior containing a granular substance and a fluid. At least one tube may be provided with one end attached to the container in communication with the interior of the container and the other end connected to a suction mechanism. When the fluid is evacuated from the container, the container constricts around the granular substance and becomes relatively rigid. An absorbent sleeve or layer may be provided surrounding the container. The granular substance may be provided as loose fill or as a layer over at least a portion of the inner wall. Alternatively, the inner walls of the container may be provided with a very rough surface. Further, the outer surface of the bottom of the pouch is enhanced frictionally.

Description:
RELATED APPLICATIONS 
     This application claims domestic priority from U.S. Provisional Patent Application No. 60/377,682, filed on May 4, 2002 and is a continuation-in-part of U.S. Non-Provisional patent application Ser. No. 10/167,350, filed on Jun. 11, 2002 and incorporates all of the teachings therein here by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The invention relates to surgical devices, and more specifically to surgical retractors for displacing organs and tissues and maintaining them in a specific position in a surgical environment. 
     2. Description of the Related Art 
     During surgery, a physician will typically work on a small area or portion of a patient and will need to push the organs and tissues that are not being treated away from the area in question. Alternatively, a physician may need to treat the underside of an organ (or another inconvenient or difficult to reach surface or section) and will need to prop it up for an extended period of time. Surgeons employ several different means of maneuvering organs and other body parts away from a surgical site and keeping them out of their way. 
     One common method uses common gauze or sponges. The surgeon essentially props up a neighboring organ with a wad of gauze or a sponge to keep the organ out of her field. This method has several drawbacks. First, surgical sponges and gauze are extremely flexible and pliant and do not offer much resistance. As a result, the organ or tissue has a tendency to flop over or push the sponge or gauze out of the way. Additionally, sponges and gauze are difficult to position or mold properly in the first place. Also, as their name suggests, sponges are extremely absorbent. Since the field is filled with bodily fluids, the sponges are constantly absorbing those fluids, which has a deleterious effect on the sponges&#39; rigidity and ability to keep back the organ or tissue. 
     U.S. Pat. Nos. 6,254,534 to Butler et al., 6,142,936 to Beane et al., and 5,159,921 to Hoover describe tubular-shaped retractors which laterally pull apart a wound opening for access into the field. These patents are silent as to the shifting of organs or blood vessels within the field, i.e., they do not teach or suggest an intra-corporeal retractor at all. U.S. Pat. No. 6,090,041 to Clark et al. describes a vacuum-actuated retractor for retracting body tissue during surgical procedures. One end of the retractor is adapted to seal with a body tissue such that a suction force is applied to the body tissue when the device is activated. A detriment to Clark&#39;s device is that the device cannot be molded to fit a specific irregular space or retain a variety of different structures as it is non-malleable. There is also a potential risk of injuring the tissue by application of the vacuum suction. 
     U.S. Pat. No. 5,460,621 to Gertzman et al. describes a composite tissue displacement sponge having multiple layers of rigid, compressed, absorbent poly vinyl acetate material. The sponge may be compressed into a rigid and dry form which allows the sponge to conform to a precise space of the cavity or site required for organ displacement or protection. The sponge may be hydrated to expand it. This device works suitably as a sponge, however it fails as a retractor that does not react at all with the organs or tissues it retains, because it is constantly absorbing fluid. 
     U.S. Pat. No. 4,889,107 to Kaufman describes a surgical retractor having a non-absorbent barrier member surrounding a malleable but shape-retaining core. 
     All of the above references teach devices which cannot be used with minimally invasive surgical procedures (e.g., laparoscopy, retroperitoneoscopy, thoroscopy) and are limited in their ability to be molded into a specific shape. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to provide a surgical retractor or tissue displacement device which can be used readily in a variety of surgical applications. 
     It is another object of the invention to provide a surgical retractor or tissue displacement device which is completely non-reactive to the organs or tissues it is retaining or displacing. 
     It is another object of the invention to provide a surgical retractor or tissue displacement device which can be used in both minimally invasive and conventional surgical situations. 
     The above and other objects are fulfilled by the invention. 
     One embodiment of the invention is a tissue displacement surgical retractor, which includes a sealed container, made from a flexible material, having an interior containing a granular substance and a fluid (e.g., a gas). At least one tube is provided with one end attached to the container in communication with the interior of the container and the other end connected to a suction mechanism. The surgical retractor is placed on a body site. Since the sealed container is a flexible material the retractor can easily conform to the body site and readily form a bottom surface which sits on the body site. When the fluid is evacuated from the container, the container constricts around the granular substance and becomes relatively rigid. The device is first molded around the tissue or organ with the tissue or organ in the desired position. The fluid (e.g., air) is evacuated, and the device retains its shape. The granular substance comprises sufficient ballast or weight so that it remains in place where positioned at the body site to perform the retraction functions. As a result, the organ or tissue is retained in place. An absorbent sleeve or layer may be provided surrounding the container. 
     The granular substance is preferably substantially incompressible; it may be provided as loose fill or as a layer over at least a portion of the inner wall. If provided as loose fill, the granular substance is preferably a biologically compatible material safely absorbable by the human body. The first end of the tube preferably includes a filter to prevent the granular substance from being evacuated along with the fluid. If provided in a layer over at least a portion of the inner wall, the granular substance prevents the slippage of one wall of the container against the other, and the device retains its shape. 
     In one embodiment, the sealed container includes at least one interior separating wall dividing the interior of the sealed container into at least two compartments. A plurality of tubes may be provided each in communication with a respective compartment. Alternatively, a single tube is provided in communication with one of the compartments and the interior separating walls are fluid permeable, so that the fluid may be evacuated from all of the compartments via the one tube. 
     Another embodiment of the invention is an intra-corporeal surgical retractor having a sealed container is made from a flexible material being conformable to substantially any desired shape. The container has interior walls having a sufficiently high coefficient of friction so that the interior walls cannot substantially slide against one another when in contact. The specific coefficient of friction may vary depending on the size and configuration of the retractor, however it is readily determinable by one of skill in the art. The container also contains a fluid. At least one tube is provided, one end of which is attached to the container in communication with the interior of the container, the other end of which is connected to a suction mechanism. When the fluid is evacuated from the container, the interior walls of the container compact together and the container becomes relatively rigid and retains its shape and remains in place due to friction and its ballast or weight. 
     The invention also includes methods of displacing intra-corporeal tissue. First, a sealed container having a granular substance and a fluid therein is provided. Next, the sealed container is conformed around the tissue to be displaced or the item to be packed. Finally, the fluid from the sealed container is evacuated, thereby leaving the sealed container in a rigid configuration, either displacing the tissue or organ or retaining the packed item. As before, the granular substance may either be loose fill or provided in a layer on at least a portion of interior walls of the sealed container. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic view of a generic embodiment of a device according to the invention. 
         FIG. 2  is a partial sectional view of a first embodiment of a device according to the invention. 
         FIG. 3  is a partial sectional view of a second embodiment of a device according to the invention. 
         FIG. 4  is a schematic view of a third embodiment of a device according to the invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     Description will now be given with reference to the attached  FIGS. 1-4 . It should be noted that these figures are merely exemplary in nature and in no way serve to limit the scope of the invention. 
       FIG. 1  illustrates the general concept of the inventive surgical retractor  5 . Bag or pouch  10  is made from an inert, non-toxic, pliable plastic or polymer and is at least partially filled with a granular substance  12 . The granular substance can be any convenient substance having a consistency similar to that of salt, sugar, sand, or the like. Although pouch  10  will be sealed and impervious to granular substance  12 , because pouch  10  might be punctured or torn accidentally (especially during surgery), using a biologically compatible material for granular substance  12  is desirable. Such granular materials may include granular sugar, polyglycolic acid, poliglecaprone 25, granular polydioxanone, or any other material safely absorbable by the human body. In any event, pouch  10  should not be completely filled with granular substance  12 ; an airspace  14  should be left in the interior of pouch  10 . The amount of granular substance  12  used will depend on the specific use. Greater amounts of granular filling provide firmer retraction. Also, the heavier or denser the material to be used is, the more “ballast” it provides, and thus the more positionally stable the device is. Thus, since the pouch  10  is flexible and is filled with granular filling  12  having ballast or weight, the pouch when placed on a body site in the conventional manner conforms to the shape needed and sits on the body site due to its ballast or weight. If the body site is flat, the bottom of the pouch will also be flat as it sits on the body site, and if the body site is irregular, the pouch will sit thereon and conform to the irregular shape before it is rendered stiff. Thus, the pouch independently stays in place due to its own weight at the body site. 
     Attached at one or more points to pouch  10  and communicating with the interior of pouch  10  is a port or connector  16 . Tubing  18  is attached at one end to connector  16 . A filter is preferably provided in connector  16  so as to prevent the egress of granular substance  12  from pouch  10  via connector  16 . The other end of tubing  18  is connected to a suction means  30 . A one-way valve  20  having a release mechanism  22  is disposed along tubing  18 . When suction means  30  is activated, it withdraws the air from pouch  10 . Since the walls of pouch  10  are pliant, the walls constrict around granular substance  12 . Because the valve  20  is one-way, air will be withdrawn from pouch  10  and not be allowed to return until and unless release  22  is depressed. 
     Suction means  30  may be of several designs, including a hand pump, an electric pump, or a central vacuum line in a building. Depending on which suction means is used, tubing  18  may be permanently connected or selectively connectable to the suction means. If the suction means  30  is a hand pump, tubing  18  may be permanently connected to the hand pump, which may take the form of a syringe, for example. By contrast, if the suction means is a central vacuum line, tubing  18  would be selectively connectable to the central vacuum line and not permanently attached. Alternatively, valve  20  can be provided in direct communication with pouch  10  and adaptable to be connected directly to suction means  30 , thereby eliminating the need for tubing  18 . 
     In operation, the invention works as follows. A surgeon operating on a patient wishes to retract or retain certain tissues or organs while working on others. The surgeon places pouch  10  in the desired body site location and molds it manually to a convenient configuration. When pouch  10  is properly configured, the surgeon or his assistant activates the suction means to withdraw the air from pouch  10 . The walls of pouch  10  constrict around granular substance  12 , and pouch  10  is rigidly fixed into a configuration; the granular substance is not able to shift or move around within pouch  10 . The pouch conforms to the body site and stays in place because of its ballast as described above. Device  5  can thus successfully keep tissues or organs out of the surgeon&#39;s way while operating. When it is desired to unfix or relax the configuration of pouch  10 , the surgeon or his assistant activates valve release  22 , and air is allowed to return to pouch  10 , and pouch  10  is no longer rigid. 
     Because device  5  has a non-rigid state, it is well-suited for use in minimally invasive surgery such as laparoscopy. The device can be inserted through a small incision and, once inside the patient, it can be manipulated through the use of tools known in the laparoscopic field. 
       FIG. 2  depicts a partial sectional view of a first embodiment of the pouch of the invention. Device  105  includes a plastic or polymer pouch  110  having loose granular fill  112  disposed therein. Space  114  is also provided as explained above. The minimum amount of space required in pouch  110  is only enough to allow the granular material  112  to shift and be malleable. Additional space could be provided. 
       FIG. 3  depicts a partial sectional view of a second embodiment of the invention. Device  205  includes a plastic or polymer pouch  210  as before. However, instead of containing loose granular fill, pouch  210  is provided with a rough or coarse granular surface inner coating  212 . Interior  214  of pouch  210  is substantially empty. When the air is evacuated from the pouch, the interior walls  211  of the pouch come into contact with one another, as indicated by arrows A in  FIG. 3 . The extremely high coefficient of friction between mating inner coating surfaces prevents the pouch  210  from moving or deforming substantially, and pouch  210  becomes rigid. It is also contemplated to provide simply an extremely rough surface that is not necessarily made from a layer of granular material being applied to the interior walls  211  of the pouch  205 . 
       FIG. 4  depicts a partial schematic view of a third embodiment of the invention. Like the first embodiment, pouch  310  contains loose granular material  12 . However, the interior of pouch  310  is compartmentalized by the provision of interior separating walls  313 . Walls  313  insure that granular material  12  remains evenly distributed throughout the interior of pouch  310 . As shown in  FIG. 4 , a single port  16  is provided. In such an embodiment, walls  313  are preferably air permeable so that the air from all of the compartments  314  can be evacuated via a single port. However, it is also contemplated that walls  313  may be air impermeable; in such an embodiment, each compartment would require its own port for the evacuation of its air. Multiple ports could be connected to multiple tubes  18 , which could be either separately controllable via individual valves or all connected to a single valve. 
     As an additional feature, as shown in  FIG. 2 , for example, an absorbent sleeve  115  may be provided around the exterior of the pouch to act as a sponge. The sleeve may be integral with the pouch or it may be removable. The provision of this outer absorbent sleeve provides additional cushioning for the supported tissues and provides increased friction to minimize any potential drift of the device within the patient. The sleeve  115  is shown as surrounding pouch  110 , however it may be provided with any of the embodiments described above or any other versions of the invention. 
     The invention is not limited to the above description. For example, the air inside pouch  10  which is withdrawn to fix the device in a specific configuration may be replaced by another gas or a liquid. In such an embodiment, the suction means may also have a pumping function to replace the specific gas to the interior of pouch  10  when it is desired to relax the configuration of the pouch. Also, the invention has been described as suitable for keeping organs and tissues out of the way of the surgeon operating on other tissues or organs, however the invention is also useful for positioning the tissue or organ that is being treated. The device is contemplated as being available in a variety of sizes and shapes (e.g., spherical, toroidal, fenestrated, oblong, irregular, etc.) for a variety of surgical applications. 
     It is further understood that the retractor stays in place because body sites themselves are not perfect surfaces and the lodging of the retractor in between body parts or on body surfaces may involve wedging into a space or frictional holding because of the nature of the surfaces and tissue. Having the retractor contain sufficient ballast or weight further ensures positional stability. 
     An additional embodiment is now described. In order to enhance the frictional holding of the retractor on a body surface, the outer surface of the pouch is roughened or comprises an enhanced frictional surface, such as corrugation. The enhanced frictional surface may be primarily on the outer surface at the bottom of the pouch. 
     The invention is not limited to the above description but rather is defined by the claims appearing hereinbelow. Modifications to the above description that include that which is known in the art are well within the scope of the contemplated invention.