Abstract:
In accordance with the present invention there is provided a surgical instrument for the removal of biological material through an opening within a patient, wherein biological material being larger than the opening within the patient. The surgical instrument includes a specimen retrieval bag having at least one wall. The specimen retrieval bag has an open end, a closed end and a longitudinal axis extending therebetween, wherein the open end is for receiving biological materials therein. The instrument further includes at least one material transfer member attached to the wall adjacent to the open end. The material transfer member extends radially from the wall and is in fluid communication with the bag. Wherein when the open end of the bag is removed from the patient through the opening and the material transfer member is at least partially removed therethrough, a portion of the biological material moves from a portion of the bag within the patient to a portion of the material transfer member outside of the patient to reduce the size of the biological material within the patient.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates, in general, to surgical instruments for retrieving tissue and, more particularly, to endoscopic surgical instruments such as pouches or specimen retrieval bags for the removal of tissue through a small incision.  
         BACKGROUND OF THE INVENTION  
         [0002]    Endoscopic surgery is a procedure wherein surgery is performed through a series of small openings or incisions in a patient. This type of surgery reduces or eliminates the need for large incisions and has changed some of the major open surgical procedures such as gall bladder removal to simple outpatient surgery. Consequently, the patient&#39;s recovery time has changed from weeks to days. These types of surgeries are used for repairing defects or for the removal of diseased tissue or organs from areas of the body such as the abdominal cavity.  
           [0003]    Of interest is the removal or excision of biological material or tissue from the body through a small incision or small natural orifice. Tissue can have many types or forms but fall into three general categories: firm tissue such as muscle and solid tumors, soft tissues such as liver, and fluid filled tissues such as a cyst, a gall bladder, a spleen, or an inflamed appendix. Some tissue can be a mix of multiple categories. For example, an inflamed gall bladder can be a mix of hardened gallstones, fluids such as bile and pus, and an outer covering of firm tissue.  
           [0004]    One challenge that exists with minimally invasive surgery is the removal of excised tissue through an opening in the body. A time-honored solution is the manual cutting of the large tissue mass into small pieces that can fit through the incision. However, with this process, fragments of tissue can be dropped and fluids can be spilled into the body cavity. This is serious if the excised tissue is cancerous or infected as this can lead to the seeding and re-spreading of cancer or the spreading of inflammation to healthy tissue.  
           [0005]    In answer to the above challenges, surgical pouches or specimen retrieval bags were developed. The specimen retrieval bags are placed endoscopically into an inner cavity of the body, the bags are opened, and the diseased tissue is placed within. The specimen retrieval bags are closed to surround and contain the tissue and fluids within. Thus, the closed specimen retrieval bag prevents the migration of tissue and fluids from the bag into the inner cavity of the body. Once the diseased tissue is placed into the open specimen retrieval bag, the bag is closed and pulled from the inner cavity through an incision or trocar. Drawstrings are typically used to close the specimen retrieval bag in the body and to draw the bag out of the opening in the body. Surgical instruments of this type are described in U.S. Pat. Nos. 5,465,731 by Bell et al. and 5,465,732 by Tovey et al. which are incorporated herein by reference.  
           [0006]    Morcellation instruments were also developed that can be used in conjunction with the specimen retrieval bags to chop or dissect large tissue masses within the specimen retrieval bags. When using a morcellation instrument, tissue is placed into the open specimen retrieval bag and the bag opening is partially drawn out of the body, leaving the tissue within the body cavity. Next, the bag is opened and the morcellator is inserted into the bag and into the portion of the bag still within the body cavity to morcellate the tissue. Suction can be used to remove morcellated tissue. A RF morcellation instrument and method of use are described in U.S. Pat. No. 5,957,884 by Michael D. Hooven and a description of morcellation is found in U.S. Pat. Nos. 5,465,731 by Bell et al. and U.S. Pat. No. 5,465,732 by Tovey et al.  
           [0007]    Whereas this method of removing tissue from the body does work, it was awkward for the surgeon to hold the bag open while morcellating and suctioning to remove pieces of tissue. If care is not exercised, the bag can be punctured or the spillage of fluids or and tissue can occur. Additionally, costly, sophisticated specimen retrieval bags are required that are resistant to cutting from the mechanical morcellator blades or RF energy.  
           [0008]    U.S. Pat. No. 5,681,324 by Kammerer et al. teaches that a square bottomed pouch (or specimen retrieval bag) enables the tissue specimen to lie across the bottom of the pouch and to impede the removal of the tissue through a trocar site (or incision). More importantly, Kammerer et al. also teaches that a tapered-bottomed pouch solves the square-bottomed pouch problem by aligning the tissue and makes it possible to remove tissue from the body cavity without enlarging the incision. Additionally, the tapered pouch shape reduces the amount of trapped air and reduces the ballooning effect when the pouch is closed and reduces the stress exerted on the pouch and abdominal wall tissue (caused by pulling the pouch through the trocar site or incision). Whereas the tapered pouch did indeed facilitate the removal of tissue, there is room for additional solutions to this problem, particularly when fluids are present within the specimen retrieval bag or within the tissue placed therein.  
           [0009]    What is needed is a specimen retrieval bag that offers all of the advantages listed above by providing a pouch or specimen retrieval bag that is easy to remove from the body. Additionally, it would be advantageous to provide an improved specimen retrieval bag that makes it easier for a surgeon to remove a specimen retrieval bag that contains fluids or materials such as chunked or morcellated tissue that that flow under pressure. Presently, there are no known specimen retrieval bags that can provide the surgeon with the improvements and benefits described above.  
         SUMMARY OF THE INVENTION  
         [0010]    In accordance with the present invention there is provided a surgical instrument for the removal of biological material through an opening within a patient, wherein biological material being larger than the opening within the patient. The surgical instrument includes a specimen retrieval bag having at least one wall. The specimen retrieval bag has an open end, a closed end and a longitudinal axis extending therebetween, wherein the open end is for receiving biological materials therein. The instrument further includes at least one material transfer member attached to the wall adjacent to the open end. The material transfer member extends radially from the wall and is in fluid communication with the bag. Wherein when the open end of the bag is removed from the patient through the opening and the material transfer member is at least partially removed therethrough, a portion of the biological material moves from a portion of the bag within the patient to a portion of the material transfer member outside of the patient to reduce the size of the biological material within the patient. 
       
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS  
       [0011]    The novel features of the invention are set forth with particularity in the appended claims. The invention itself, however, both as to organization and methods of operation, together with further objects and advantages thereof, may best be understood by reference to the following description, taken in conjunction with the accompanying drawings in which:  
         [0012]    [0012]FIG. 1 illustrates an isometric view of a cross section of the abdominal wall and an improved specimen retrieval bag mounted on a specimen retrieval bag instrument, the improved specimen retrieval bag receiving a gall bladder from a surgical grasping instrument within the abdominal cavity;  
         [0013]    [0013]FIG. 2 illustrates an enlarged isometric view of a distal end of the improved specimen retrieval bag instrument of FIG. 1 prior to the receipt of the gall bladder, wherein a novel blister feature extends from a wall of an improved specimen retrieval bag;  
         [0014]    [0014]FIG. 3 is a top view of the improved specimen retrieval bag of FIG. 2, wherein the blister features extend outwardly from the walls of the improved specimen retrieval bag;  
         [0015]    [0015]FIG. 4 is an is an enlarged isometric view of a prior art specimen retrieval bag wherein the prior art specimen retrieval bag is open and a gall bladder and fluid are placed therein;  
         [0016]    [0016]FIG. 5 illustrates a cross-sectional view wherein the opening of the prior art specimen retrieval bag of FIG. 4 is being pulled through an incision within the abdominal wall and the gall bladder and fluid are ballooning the prior art specimen retrieval bag within an abdominal cavity;  
         [0017]    [0017]FIG. 6 a cross-sectional view of the abdominal wall and the prior art specimen retrieval bag of FIG. 5, wherein the prior art specimen retrieval bag is being pulled through an incision and the forces exerted upon the prior art bag are shown;  
         [0018]    [0018]FIG. 7 a cross-sectional view of the abdominal wall and the improved specimen retrieval bag of FIG. 2, wherein the improved specimen retrieval bag is being pulled through an incision with a gall bladder and fluid within, and the forces exerted upon the improved specimen retrieval bag are shown;  
         [0019]    [0019]FIG. 8 is a cross sectional view of the of the abdominal wall and the improved specimen retrieval bag of FIG. 7, wherein the improved specimen retrieval bag is being pulled through an incision, and fluids are flowing from a lower portion of the specimen retrieval bag into an upper portion of the blisters of the improved specimen retrieval bag to reduce the size of the lower portion;  
         [0020]    [0020]FIG. 9 is a cross sectional view of the of the abdominal wall wherein a first alternate embodiment of the improved specimen retrieval bag of FIG. 5 is shown;  
         [0021]    [0021]FIG. 10 is a cross sectional view of the of the abdominal wall wherein a second alternate embodiment of the improved specimen retrieval bag of FIG. 5 is shown; 
     
    
     DETAILED DESCRIPTION OF THE INVENTION  
       [0022]    The present invention relates, in general, to surgical instruments for retrieving excised tissue from a patient and, more particularly, to endoscopic surgical instruments such as pouches or specimen retrieval bags for the removal of tissue through a small incision.  
       Present Invention Instrument  
       [0023]    In FIG. 1, the present invention is an improved specimen retrieval bag  25  shown removably attached to a distal end  41  of a deployment instrument  40 . The deployment instrument  40  is shown inserted into an abdominal cavity  45  of a patient through a first incision  47  within a patient&#39;s abdominal wall  46 . A trocar  55  is inserted into a second incision  48  within the abdominal wall  46  and has a grasping instrument  60  inserted within a cannula  56  (not shown) of the trocar  55 . Alternately, if desired, the improved specimen retrieval bag  25  can be drawn into the cannula  56  of the trocar  55  (not shown). Grasping instrument  60  is shown gripping a gall bladder  70  over an opening  26  of the improved specimen retrieval bag  25  just prior to placement of the gall bladder  70  therein.  
         [0024]    [0024]FIGS. 2 and 3 are enlarged views of the improved specimen retrieval bag  25  of the present invention releasably attached to a distal end  41  of the deployment instrument  40 . Improved specimen retrieval bag  25  has two opposing walls  27   a  and  27   b  that when joined form a single wall, hereafter referred to as wall  27 . The wall  27  is formed from at least one layer of a resilient or flexible material, and has an opening  26  shown in the open position, and a bottom  31 . A material transfer member or blister  28  extends outwardly from each wall  27  generally perpendicular to the opening  26  of the improved specimen retrieval bag  25 . In FIG. 2 the far side blister  28  is removed for clarity. Channels  29  are located in the improved specimen retrieval bag  25 , one along each side of the opening  26 . Each channel  29  slidably receives one of a pair of flexible arms  42  extending from the distal end  41  of the deployment instrument  40 . When the surgeon desires to detach the improved specimen retrieval bag  25  from the deployment instrument  40 , the pair of flexible arms  42  withdraw into the deployment instrument  40  to release the improved specimen retrieval bag  25 . A drawstring  30  is threaded through each of the channels  29  and extends into the deployment instrument  40 .  
         [0025]    Improved specimen retrieval bag  25  of the present invention is formed from a pair of opposed walls  27  that are made of at least one layer of elastomeric or polymeric material. The walls  27  are tapered to facilitate removal of the improved specimen retrieval bag  25  from the first incision  47 . Walls  27  are constructed from at least one layer of an elastomeric or polymeric material such as Polyurethane, Polyethylene, Polypropylene, Silicone, Vinyl, or Teflon. Multiple layer construction of the walls  27  are common and can incorporate flexible metal meshes, thermoformed plastic meshes, fabrics, or Kevlar for reinforcement. As shown, walls  27  are formed from flat sheets of Polyurethane and are cut into a desired shape with sides  37  tapered as shown. Blister  28  is formed into a wall  27  by the application of heat, pressure, impact, ultrasonic energy or any combination thereof. Blisters  28  are formed in the wall  27  such that when the walls  27  are loaded in tension such as in the vertical direction at the opening  26  and bottom  31 , the stresses travel within in the flat portions of the walls  27  and around the blisters  28 . This is somewhat analogous to the manner in which stresses travel around a hole in a part when the part is in tension. The opposed walls  27  are orientated with the blisters  28  extending outwardly as shown, and the walls  27  are sides  37  are glued, heated, or ultrasonically welded together along the sides  37  and bottom  31 . Alternately, the Improved specimen retrieval bag  25  can be molded or dip formed into a desired configuration.  
       Prior Art Instrument Description  
       [0026]    [0026]FIG. 4 illustrates a prior art retrieval bag  80 . Some of the elements are common to both the prior art bag  80  and the improved specimen retrieval bag  25  bag described previously. When like elements, or nearly identical elements exist, they will have the same element numbers, general descriptions, and generally the same functions. Likewise, generally similar patient anatomy or bag contents will have the same element numbers and descriptions.  
         [0027]    As shown in FIG. 4, prior art retrieval bag  80  contains contents  72 , an excised gall bladder  70  and fluid  71 . The excised gall bladder  70  has been placed into an opening  26  of the prior art retrieval bag  80  and fluid  71  has leaked from the gall bladder  70 . Fluid  71  from the gall bladder  70  excision consists of bile, blood, or pus, and any combination thereof. Prior art retrieval bag  80  is attachable (not shown) to the deployment instrument  40  (FIG. 1) in the manner previously described for the improved specimen retrieval bag  25 .  
         [0028]    Channels  29  are provided surrounding the opening  26  of the prior art retrieval bag  80  for the reception of the flexible arms  42  extending from the deployment instrument  40  (FIG. 1). Drawstring  30  is placed into the channels  29  for closing the opening  26  of prior art retrieval bag  80 . Prior art retrieval bag  80  is generally formed from a pair of opposed walls  27  that are made of at least one layer of the materials described above for the improved specimen retrieval bag  25 . Sides  37  and bottom  31  are welded, attached or glued together. The sides  37  are not tapered.  
       Prior Art Instrument—Method of Use and Force Analysis During Removal  
       [0029]    [0029]FIGS. 5 and 6 illustrate the method of pulling the prior art retrieval bag  80  containing contents  72  through an incision, and the forces involved in pulling the prior art retrieval bag  80  and the contents  72  through the incision. The description of the method of use of the prior art retrieval bag  80  is provided so that the reader can better understand novel advantages provided with the improved specimen retrieval bag  25  of the present invention which will be discussed in detail below.  
         [0030]    As shown in FIGS. 5 and 6, the prior art retrieval bag  80  is being withdrawn from the abdominal cavity  45  of a patient. Prior to the view of FIGS. 5 and 6, the following steps have occurred. First, the prior art retrieval bag  80  has been placed into the patient&#39;s abdominal cavity on a deployment instrument  40 , and a fluid filled gall bladder  70  is placed therein. The prior art retrieval bag  80  is then closed, released from the deployment instrument  40 , and the deployment instrument  40  is then removed from the first incision (not shown).  
         [0031]    Next, as shown in FIGS. 5 and 6, an upward tensile force F is applied to the drawstrings  30 . This force F is pulling the prior art retrieval bag  80  and contents  72  through the first incision  47  within abdominal wall  46 . As shown, the partially removed prior art retrieval bag  80  has an upper columnar shaped portion, henceforth referred to as column  32 , which is under tension from force F and extends from the first incision  47 . Prior art retrieval bag  80  also has a lower spherical shaped portion referred to as balloon  33  which assumes the spherical shape from the compression of the contents  72  therein. Balloon  33  is located within the abdominal cavity  45  just below the first incision  47 .  
         [0032]    [0032]FIG. 6 is a cross section of the prior art retrieval bag  80  of FIG. 5 showing the balance of physical forces therein as the prior art retrieval bag  80  and contents  72  (gall bladder  70  and fluid  71 ) are being pulled through the first incision  47 . Fluids  71  are present within the contents  72  and are indicated by dashed horizontal lines. The walls  27  of the prior art retrieval bag  80  are replaced with arrows to indicate tensions found within the walls  27  from the forces exerted thereon. The tension arrows will also be referred to as walls  27 . As shown in FIG. 6, the upwards motion of the prior art retrieval bag  80  brings the balloon  33  into contact with an inner side of the abdominal wall  46  at first incision  47  and biases the walls  27  of column  32  inwardly. This contact produces a downward and inward abdominal wall contact force F TISSUE  on the walls  27  of the balloon. The abdominal wall contact force F TISSUE  opposes the tension force F and places the walls  27  of the column  32  under tension as indicated by tension arrows T 2 .  
         [0033]    The upwardly motion of prior art retrieval bag  80  and the inwardly and downwardly abdominal wall contact force F TISSUE  squeezes the contents  72  within the balloon  33 . As the prior art retrieval bag  80  is pulled through the first incision  47 , the balloon  33  gets smaller and the walls  27  of the balloon  33  constrict the contents  72  of the balloon  33  inwardly. The constricting walls  27  of the balloon  33  are opposed by the incompressible contents  72  which exert radially outward pressure vectors P 1  on the walls  27  of balloon  33 , and the force F creates a tension T 1  within the walls  27  of the balloon  33 .  
         [0034]    The constricting walls  27  force fluids  71  to flow from balloon  33  into the column  32 . The opening  26  of the prior art retrieval bag  80  is not fully sealed and air leaks from the opening  26  enabling the fluids  71  to rise within the column  32 . The weight of the column of fluids  71  push outwardly with a force P 2  on the walls  27  of the column  32  and try to bulge the walls  27  above the abdominal wall  46  outwardly. However, the reader is advised to note that the tension forces T 2  within the walls  27  of the column  32  are higher than the fluid force P 2  and the walls remain in the columnar shape of column  32 . Thus, tension forces T 2  control the volume within the column  32 . Fluid  71  can rise into the limited volume defined within the column  32  of the prior art retrieval bag  80  until all of the air flows out of gaps within the opening  26 , and the fluid  71  reaches the opening  26 . At this point, if the balloon  33  is small enough, the balloon  33  slips through the first incision  47  and the prior art retrieval bag  80  is extracted.  
         [0035]    If the balloon  33  is too large to fit through the incision and the column  32  is filled with fluid  71 , continuing to draw the prior art retrieval bag  80  out of the first incision  47  can force fluid  71  out of the opening  26  when it is closed. This spillage of fluids  71  complicates the surgery and can require the use of a suction instrument to remove the fluids  71  seeping from the opening  26 . In some cases it is necessary to re-open the opening  26  and to use suction or forceps to extract some of the contents  72  therefrom. In some cases, it can be necessary to increase the length of the first incision  47  to remove the prior art retrieval bag  80 , or to use scissors or a morcellator on the contents  72  to facilitate removal of the prior art retrieval bag  80 .  
       Improved Instrument—Method of Use and Force Analysis During Removal  
       [0036]    [0036]FIGS. 7 and 8 are cross-sections of the improved specimen retrieval bag  25  of the present invention being pulled or removed from the first incision  47 . These FIGS. illustrate the method of use of the present invention and the balance of forces between the improved specimen retrieval bag  25 , the abdominal wall and the contents  72  therein. The reader is advised to review the above sections describing prior art specimen retrieval bag  80  for comparisons.  
         [0037]    Prior to the view of FIGS. 7 and 8, the improved specimen retrieval bag  25  on the deployment instrument  40  was placed into the abdominal cavity  45  (FIG. 1) and a gall bladder  70  was placed therein. The improved specimen retrieval bag  25  was closed, and then released from the deployment instrument  40 . Finally, the deployment instrument  40  was removed from the first incision  47 .  
         [0038]    Next, an upward tensile force F is applied to draw the improved specimen retrieval bag  25  and contents  72  consisting of gall bladder  70  and fluid  71  through the first incision  47  and out of the patient. FIG. 7 shows a cross section of the improved specimen retrieval bag  25  (taken across the blisters  28 ) as it is being partially drawn upwards through the first incision  47  by tensile force F.  
         [0039]    The cross section of FIG. 7 is taken across the blisters  28  of the improved specimen retrieval bag  25  and shows the forces involved therein. As described previously, the walls  27  and the blisters  28  are designed such that when the walls  27  are placed under tension (from the force F), the tensile forces travel within the walls  27  and around the blisters  28 . Thus, the upper force F exerts tension on the walls  27  and not on the blisters  28 . In FIG. 7 walls  27  are outlined by the tension arrows T 3  and T 4 . The blisters  28  are not under tension from the force F.  
         [0040]    The contents  72  of the improved specimen retrieval bag  25  are being compressed or constricted within the balloon  33  and exert an outwards force P 3  on the portion of the walls  27  and blister  28  of the balloon  33 . In FIG. 7, the contents  72  consist of gall bladder  70  and fluid  71 . The upwards motion of the improved specimen retrieval bag  25  constricts the contents  70  of the balloon  33  and forces the fluid  71  to rise into the portion of the improved specimen retrieval bag  25  extending above the incision  47 . The constriction compresses the contents  72  within the balloon  33  and the contents  72  exert a radially outwards force P 3  on the portion of the walls  27  and blister  28  of the balloon  33 . This outward pressure has tensioned the walls  27  of the balloon  33  as indicated by the tension arrows T 3 , and has expanded blisters  28  outwardly from the balloon  33 .  
         [0041]    As the improved specimen retrieval bag  25  is advanced upwardly by force F, fluid  71  moves upwardly from the constricted balloon  33  and into the column  32 , expanding the non-tensioned portions NT of the blisters  28  outwardly outside of the incision  47 .This movement of fluids  71  into the non-tensioned portions NT of the blisters  38  reduces the size of the contents of the balloon  33 , enabling the improved specimen retrieval bag  25  to be pulled farther out of the first incision  47 . As more of the improved specimen retrieval bag  25  moves out of the body, more the non-tensioned portions NT of the blisters  38  emerge from the first incision  47  and more fluids  71  can move upwardly from the balloon  33  into the non-tensioned portions NT of the blisters  28 . This fluid transfer process continues until the improved specimen retrieval bag  25  and contents  72  are easily extracted from the patient.  
         [0042]    [0042]FIG. 8 is a cross-section of the improved specimen retrieval bag  25  across vertical axis B-B and the blisters  28  showing an embodiment of the method steps of using the present invention to remove a fluid filled organ such as a gall bladder  70 . Gall bladder  70  is first placed into the improved specimen retrieval bag  25  and a cut  74  is placed into the gall bladder  70  to release the fluids  71  within. Next, the improved specimen retrieval bag  25  is closed, and the improved specimen retrieval bag  25  is pulled out of the first incision  47 . As shown, pulling the improved specimen retrieval bag  25  through the first incision  47  compresses the gall bladder  70 , squeezing fluids  71  from the cut  74 . The flow of fluids  71  from the gall bladder  70  reduces the size of the organ and makes it easier to draw the organ through the first incision  47 . As described above, the fluids  71  flow easily from the cut  74  within the squeezed gall bladder  70 , into the column  32  and into the non-tensioned portions NT of the blisters  28 . This flow of fluids  71  into the non-tensioned portions NT of the blisters  28  reduces the size of the balloon  33 , and facilitates the removal of the improved specimen retrieval bag  25  from the patient.  
         [0043]    [0043]FIGS. 9 and 10 illustrate alternate embodiments of the improved specimen retrieval bag  25 . FIG. 9 shows an alternate embodiment of improved specimen retrieval bag  25  bag without blisters  28  but having an expandable element located adjacent to the opening  26 . As shown, the expandable element is a bellows  34  that easily expands outwardly when pressurized. As the bellows  34  expands outwardly, fluids flow from the balloon  33 , into the column  32  and into the bellows  34 . Alternately, placing an elastomeric panel placed within the walls  27  of the improved specimen retrieval bag  25  will also meet the intent of the alternate embodiment.  
         [0044]    [0044]FIG. 10 shows yet another alternate embodiment of the improved specimen retrieval bag  25  having an alternate embodiment of the transfer portion for the transport of fluids out of the patient. This alternate transfer portion has a hollow fluid passage  35  for the transfer of fluid from the balloon  33  into a receptacle  36  located outside of the abdominal wall  46 . Hollow fluid passage  35  has a first end and a second end. Pulling the balloon  33  through the first incision  47  moves fluids  71  through the hollow fluid passage  35  and into the receptacle  36 .  
         [0045]    Whereas the above descriptions describe a fluid  71  as a substance such as blood, bile, pus, or other bodily liquid, it is conceivable that other materials may be considered as liquids or fluids in certain situations. For example, morcellated tissue is of a paste-like consistency and can be made to flow (like a fluid) within a confined container with pressure. Additionally, pieces of other solid or semi-solid materials (such as tissue or dry substances) can be made to move in a more fluid-like manner when combined with a fluid  71 , which acts as a lubricant. Thus, the addition of a fluid  71  such as saline, water, (or any one of a number of other liquids) to the improved specimen retrieval bag  25  can aid in the movement of tissue within the bag. Thus the fluids  71  described above can encompass a much wider range of materials than those listed above, including morcellated tissue, and in some cases, larger pieces of tissue.  
         [0046]    While preferred embodiments of the present invention have been shown and described herein, it will be obvious to those skilled in the art that such embodiments are provided by way of example only. Numerous variations, changes, and substitutions will now occur to those skilled in the art without departing from the invention. Accordingly, it is intended that the invention be limited only by the spirit and scope of the appended claims.