Patent Publication Number: US-9414817-B2

Title: Surgical tissue retrieval instrument and method of use of a surgical tissue retrieval instrument

Description:
PRIORITY 
     This utility application is a continuation of and claims the benefit of U.S. Utility application Ser. No. 13/309,854, filed on Dec. 2, 2011, currently patented as U.S. Pat. No. 8,870,894 issued on Oct. 28, 2014, which in turn is a continuation of and claims the benefit of U.S. Utility application Ser. No. 12/079,172, filed on Mar. 24, 2008, currently patented as U.S. Pat. No. 8,075,567 issued on Dec. 13, 2011, which in turn claims priority benefit to U.S. Provisional Application No. 60/919,386 filed Mar. 22, 2007. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     This invention relates to the field of surgical instruments for retrieving internal body tissue and, more particularly, to a surgical instrument used in endoscopic surgery for retrieving internal body tissue with an endoscopic pouch. 
     2. Background of the Invention 
     Tissue retrieval devices have been developed for use in endoscopic surgery to remove tissue from a patient&#39;s body. Typically these devices comprise a specimen-collecting pouch placed at the distal end of a pusher rod. The pusher rod is inserted into the patient&#39;s body via a tiny insertion and the pouch is deployed once it is near the surgical site. Gaining close proximity to the tissue to be removed, placing the tissue in the pouch, closing the pouch, and removing the now-filled pouch from the body are the main steps to be performed with the device. 
     Pouches used with tissue retrieval devices often employ a means for closing the pouch to prevent spillage of tissue or fluids into the patient&#39;s body. Typical closure means include a drawstring or a wire loop. 
     In many state of the art devices, the mouth of the pouch does not allow for easy collection of the sample and/or removal of the pouch from the patient&#39;s body. This is because of problems associated with the slipknot often used to initially close the pouch. For example, in some prior art devices, once the pouch is closed it cannot be reopened until the pouch is removed from the patient. 
     A surgical retrieval device with a drawstring for closing the pouch is disclosed by Clayman et al., U.S. Pat. No. 5,037,379. The drawstring is used to close the bag closed and pull the bag from the body cavity through a tube. 
     Kindberg et al., U.S. Pat. No. 5,143,082, discloses a surgical device for enclosing a body organ or tissue and which includes a strand extending through a tube and formed into a noose about the open end of a surgical bag. 
     Wetter et al., U.S. Pat. No. 5,190,555, discloses another endoscopic tissue retrieval device that includes a drawstring used for closing and opening a funnel-shaped bag. 
     U.S. Pat. Nos. 5,465,731 and 5,647,372 disclose yet another endoscopic tissue retrieval comprising a pouch supported by a closed metal loop. The bag is ripped away from the metal loop during the drawstring closure along a perforated line circumscribing the mouth of the pouch. 
     The aforementioned patents and device are not admitted to be prior art by their mention in this Background section. 
     Many state-of-the-art pouches fail during their removal from the patient. This is because a great deal of force is applied to a filled bag as a surgeon attempts to pull it through the typically tiny laparoscopic surgical incision made in the skin and muscle layers of the patient. 
     Separately, bags often come into contact with sharp surgical instruments and rip as a result. 
     A need exists in the art for a reliable tissue retrieval device comprising a sturdy bag with a large mouth that is securely attached to its support but that can be released from the support without having to close the mouth of the bag. Such a device should also allow full access to the retrieval pouch prior to insertion into the patient so as afford in situ pre-treatment of the bag. Furthermore, the device should provide a means for preventing accidental deployment or closure of the pouch as well as accidental removal of the pouch from its support during collection of tissue. The device should also provide a means to scrape tissue from adjacent adhering structures for more efficient tissue extraction from the body. 
     SUMMARY OF THE INVENTION 
     An object of this invention is to provide a tissue retrieval device for use in endoscopic surgery that overcomes many of the disadvantages in the prior art. 
     Another object of the invention is to provide a surgical tissue retrieval device comprising a pouch which is securely but removably attached to a support. A feature of this invention is a means for facilitating repeated deployment, opening, and closing of the pouch while the pouch is still confined inside the patient. An advantage of this invention is that it allows quick release of the pouch from its support without having to lock or close the mouth of the pouch. Another advantage of this invention is that it allows a surgeon to serially collect samples while the device remains inside the body and to securely close and reopen the pouch. 
     Yet another object of the invention is to provide an endoscopic collection device that enables a surgeon to remove tissue and treat unremoved tissue. A feature of an embodiment of this invention is a pouch propped open by two elongated substrates of unequal length that are slidably received by the pouch, and held in position by the action of a controlling toggle. An advantage of this invention is that a portion of the mouth of the pouch remains taut while the pouch is open and can be used as a straight scraping edge. Another advantage of this invention is that it allows the pouch to be rotated or moved transversely while the pouch is either closed or opened. This allows a surgeon to retrieve tissue that tends to adhere to nearby anatomical structures such as organs, mesentery, and surrounding structures. Another advantage of this invention is that it allows a surgeon to retrieve tissue by providing a means for positioning the tissue-collecting portion of the device in regions located generally perpendicular to or lateral from the longitudinal axis of the device. 
     A further object of the present invention is to provide a tissue retrieval tool for use in laparoscopic procedures. A feature of the device is a means for reversibly deploying the tissue removal bag and reversibly opening and closing the bag both inside and outside the body. An advantage of the invention is that a deployed bag outside the body allows medical personnel to manipulate the bag and to pretreat the bag prior to inserting the bag into its delivery sleeve in preparation for entry into the patient. Another advantage of the invention is that it allows a bag, once deployed inside the body to be repeatedly closed and reopened inside the body, thereby enabling a surgeon to collect tissue while preventing any spillage thereof during varying, protracted harvesting procedures conducted inside the body. 
     In brief, this invention provides a surgical device for retrieving internal body tissue during laparoscopic and other surgical procedures, the device comprising a sleeve having a proximal end and a distal end, said distal end adapted for insertion in a cannula, a rod in slidable and rotatable communication with said sleeve, said rod having a distal end supporting a toggle and laterally biased jaws and a proximal end comprising a handle to manipulate the rod, and a pouch in slidable communication with the jaws and toggle, wherein the toggle facilitates simultaneous detachment of the pouch from the jaws and the rod. 
     The invention also provides a device for removing tissue from a patient&#39;s body, the device comprising: a sleeve having a proximal end and a distal end, said distal end adapted for insertion in a cannula; a pusher rod in slidable communication with said sleeve, the rod having a distal end terminating in laterally biased jaws and a proximal end terminating in a handle; a toggle pivotally mounted to the rod intermediate the proximal end and the distal end, such that the toggle swings from a first spring loaded position to a second resting position; and a pouch in slidable communication with the jaws and toggle; wherein the toggle allows disengagement of the pouch from the jaws when in the second resting position. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWING 
       The foregoing and other objects, aspects, and advantages of this invention will be better understood from the following detailed description of the preferred embodiments of the invention with reference to the drawing, in which: 
         FIG. 1  is an overall perspective view of an exemplary embodiment of a surgical device for retrieving internal body tissue, in accordance with features of the present invention; 
         FIG. 1 a    is a cross-sectional view of  FIG. 1  along line 1a-1a; 
         FIG. 2 a    is a profile exploded view of an exemplary embodiment of a surgical device for retrieving internal body tissue, in accordance with features of the present invention; 
         FIG. 2 b    is a perspective exploded view of an exemplary embodiment of a surgical device for retrieving internal body tissue, in accordance with features of the present invention; 
         FIG. 2 c    is a plan exploded view of pouch supports of an exemplary embodiment of a surgical device for retrieving internal body tissue, in accordance with features of the present invention; 
         FIG. 2 d    is a profile view of  FIG. 2 c    taken along line 2d-2d. 
         FIG. 2 e    is a detail view of a pouch support for a surgical device for retrieving internal body tissue, in accordance with features of the present invention; 
         FIG. 3  is a schematic plan view of a pouch opening for a surgical device for retrieving internal body tissue, in accordance with features of the present invention; 
         FIG. 4 a    is a detailed profile view of a toggle mechanism for a surgical device for retrieving internal body tissue, in accordance with features of the present invention; 
         FIG. 4 b    is a detailed plan view of a toggle mechanism for a surgical device for retrieving internal body tissue, in accordance with features of the present invention; 
         FIG. 4 c    is a profile view of an alternative embodiment of a toggle mechanism for a surgical device for retrieving internal body tissue, in accordance with features of the present invention; 
         FIG. 4 d    is a view of  FIG. 4 c    taken along line 4d-4d; 
         FIG. 4 e    is a profile view of an alternative embodiment of a toggle mechanism for a surgical device for retrieving internal body tissue, with said mechanism engaged in the hem of the device&#39;s pouch, in accordance with features of the present invention; 
         FIG. 4 f    is a view of the toggle mechanism for a surgical device for retrieving internal body tissue depicted in  FIG. 4 e    with said toggle about to be disengaged from the hem of the device&#39;s pouch, in accordance with features of the present invention; 
         FIG. 4 g    is a view of the toggle mechanism for a surgical device for retrieving internal body tissue depicted in  FIG. 4 e    with said toggle disengaged from the hem of the device&#39;s pouch, in accordance with features of the present invention; 
         FIG. 4 h    is a detail view of an alternative embodiment of a toggle mechanism for a surgical device for retrieving internal body tissue depicted in  FIG. 4 e   , in accordance with features of the present invention; 
         FIG. 4 i    is a detail view of a toggle mechanism and retrieval pouch for a surgical device for retrieving internal body tissue, in accordance with features of the present invention; 
         FIG. 4 j    is a detail view of an alternative embodiment of a toggle mechanism and retrieval pouch for a surgical device for retrieving internal body tissue, in accordance with features of the present invention; 
         FIG. 5 a    is a detailed view of an alternative embodiment of a toggle mechanism for a surgical device for retrieving internal body tissue, with said toggle fully contained in an introducer tube, in accordance with features of the present invention; 
         FIG. 5 b    is a detailed view of the toggle depicted in  FIG. 5 a    with said toggle partially contained in an introducer tube, in accordance with features of the present invention; 
         FIG. 5 c    is a detailed view of the toggle depicted in  FIG. 5 a    after said toggle has exited an introducer tube, in accordance with features of the present invention; 
         FIGS. 6 a -6 d    is a sequence of detailed views of the relative orientation of a pouch and a toggle post for a surgical device for retrieving internal body tissue, in accordance with features of the present invention; 
         FIGS. 7 a  and 7 b    are, respectively, schematic front and back views of a handle assembly for a surgical device for retrieving internal body tissue, in accordance with features of the present invention; 
         FIG. 7 c    is a detailed view of the orientation of the handle assembly depicted in  FIGS. 7 a  and 7 b    when the surgical device for retrieving internal body tissue is inserted in a patient, in accordance with features of the present invention; 
         FIGS. 8 a -8 f    is a sequence of views illustrating the operation of a surgical device for retrieving internal body tissue; in accordance with features of the present invention; 
         FIG. 8 e     1  is a detailed view of the fork, pusher rod, and handle assembly comprised in the surgical device for retrieving internal body after this assembly is removed from a patient, in accordance with features of the present invention; and 
         FIG. 8 e     2  is a detailed view of the relative handle and the handle housing orientation depicted in  FIG. 8 e    for the surgical device for retrieving internal body when this device is removed from a patient, in accordance with features of the present invention. 
     
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
     The present invention provides a surgical tissue retrieval device for use in endoscopic surgery which overcomes disadvantages in the prior art. The device comprises a collapsible pouch defining a mouth, the mouth defined by a periphery which removably receives a plurality of elongated support jaws; and a toggle mechanism serving as a means for controlling the deployment, opening, and closing of the support jaws, and, therefore, the opening and closing of the mouth of the pouch. 
     The present invention also provides a device for removing tissue from a patient&#39;s body comprising a sleeve having a proximal end and a distal end, with said distal end adapted for insertion into a cannula; a rod in slidable and rotatable communication with said sleeve, the rod having a distal end terminating in a plurality of laterally biased jaws. A toggle is also positioned on the rod intermediate the jaws and proximal the end. A pouch is in slidable communication with the jaws and the toggle, wherein the toggle facilitates loading of the pouch during collection of tissue and detachment of the pouch from the jaws when this collection is terminated. 
       FIG. 1  is an overall perspective view of an exemplary embodiment of the invented device  10 . The device facilitates retrieval of internal body tissue through a sleeve (i.e. an ‘introducer’)  35  inserted into the body wall of a patient through a cannula (not shown). The surgical device further comprises an elongated substrate  30  such as pusher rod. The rod  30  is terminated by a plurality  40  of elongated jaws  41 ,  42  which when fully deployed in a spring biased position and viewed together resembles a circle. The pusher rod  30  is slidably received by the introducer  35 . A proximal end of the rod terminates into a handle assembly comprising a handle  71  in slidable communication with a handle housing  72  containing a gasket  81  positioned through which the pusher rod  30  is slid through. The gasket is in frictional contact with both the rod and an inside surface of the introducer tube so as to prevent fluid communication (e.g. gas leakage) from the distal end to the proximal end of the sleeve  35 . The top face  76  of the handle  71  comprises a protrusion  75  adapted to rest within a slot  83  on the top face  80  of the housing  72 . (See detailed discussion infra of the handle assembly and its operation as related to  FIGS. 7 and 8 .) 
     In one embodiment, two elongated jaws are provided, with one jaw longer than the other such that the heretofore mentioned circular shape terminates in a cord line CL, so designated in  FIG. 1 . (Jaws of equal length can also be used.) These elongated jaws  41 ,  42  resemble a hanger or fork which slidably receives a collar (defining a mouth) of a collapsible pouch  20 , such that the pouch, when so engaged, depends from the distal end of the pusher rod  30 . The elongated jaws  41 ,  42  are spring biased such that when deployed (i.e. slid clear of the confines of the introducer  35 ), the jaws extend laterally (i.e., perpendicularly away from the longitudinal axis a of the device) to prop open the mouth of the pouch. 
     The cord line CL of the pouch serves as a straight edge, held taught by the biasing configuration of the deployed jaws, so as to provide a scraping function to the distal end of the device along that edge. 
     As can be seen in  FIG. 2 c   , the device provides a means for repeatedly opening and closing the mouth of the pouch. Specifically, when the rod  30  is pulled toward the proximal end, the roots  44  of the jaws contact the distal end  31  of the introducer tube  35  so as to cause the jaws to converge, thereby closing the pouch. When the rod is pushed towards its distal end, the jaws bias laterally as described supra, allowing the mouth to prop up again. 
     Deployment and manipulation of the pouch  20  is also controlled by a toggle mechanism  50 . The toggle mechanism  50  also serves as a means for decoupling the elongated jaws  41 ,  42  from the pouch  20 . As noted supra, while engaged in the pouch, the jaws allow repeated partial opening and closing of the device so that a surgeon can collect a specimen at one site, partially close the jaws, move the pouch to another site, reopen the pouch, collect another specimen, and repeat these steps until all the required specimens are collected. 
       FIGS. 2 a  and 2 b    are exploded views of a preferred embodiment of the surgical device  10  for retrieving internal body tissue. The introducer tube  35  is used to insert a pusher rod  30  into a patient via a cannula. The pusher rod  30  is terminated by the two jaws (i.e. elongated spring-biased substrates) such that when fully deployed outside of the introducer, the jaws resemble two curved forks shaped as a partial circle. The collapsible pouch  20  is supported by equal length jaws  41 ,  42 , so as to hang downwardly by the force of gravity. 
     The opening or mouth  25  of the pouch  20  is propped open by the laterally extended elongated jaws  41 ,  42 . Specifically, the jaws are removably received by a collar or hem  27  defining the mouth  25  of the pouch  20 . A perspective view of the pouch and jaws is found in  FIG. 2 b   . The collar defines a channel  23  that circumscribes the mouth  25  of the pouch  20 , with each end of the channel terminating with openings  29  positioned side by side and at a proximal region of the collar. The openings  29  provide a means for the elongated jaws to access the channel  23  and to slidably communicate with the pouch so as to define the shape of the mouth  25  of the pouch  20 . 
     Intermediate the channel openings is a region of the pouch defining an aperture  28  adapted to removably receive the distal end  67  of the toggle  50 . 
     Jaws Detail 
     The elongated jaws  41 ,  42  are formed of reversibly deformable material and, in their unconstrained state (i.e. their fully deployed uncompressed state), they form a loop  43 , or a portion thereof, and such that the mouth  25  of the pouch  20  assumes the shape of the loop  43 , with a gap  143  between the jaws. In an alternative embodiment, one elongated jaw forming substrate may be straight and the other one curved. The jaws may be of equal length (See  FIG. 2 b   ) or one may be longer than the other (See  FIG. 2 c   ). Each of the jaws can be chosen of variable lengths to shape the mouth  25  into the desired shape. For example, they can be compressed (i.e. reversibly deformed) to form two parallel linear members slidably received (with the jaws in their compressed state, i.e. in an undeployed configuration) by the distal end  31  of the introducer  35  for later deployment of the mouth  25  of the pouch  20  inside the patient. This is particularly advantageous as the invented device is delivered to the surgeon with the bag engaged by the pincers and deployed from the introducer tube. This allows the surgeon or the surgical suite personnel to pre-treat the bag prior to loading it into the distal end of the introducer tube. 
     Pincers of uneven length provide an appreciable amount of flexibility to left-handed or right-handed surgeons, allowing them to select the pincer configuration most convenient to them depending on the area where they are operating and special precautions that must be taken to avoid impacting neighboring organs. 
       FIG. 2 c    is a top view of the fork, toggle, and pusher rod assembly and  FIG. 2 d    is a profile view of the fork, toggle, and pusher rod assembly taken along line 2d-2d of  FIG. 2   c.    
     Preferably, each of the elongated jaws  41 ,  42 , have an oblong cross section  47 , with the longer dimension of the cross section perpendicular to the plane p (phantom triangle depicted in dotted lines), as depicted in  FIG. 2 e   . This feature limits bending of the jaws orthogonally to said plane when the jaws encounter resistance as the pouch collects a sample or when the filled pouch is weighed down by the tissue contained therein. The jaws have preformed curvatures which force the jaws  41 ,  42  into an expanded (i.e. relaxed) loop shape  43  when the jaws are extended or deployed from the distal end of the introducer  35 . The jaws are flexible enough to be deformed into parallel rectilinear members that can be slid through the introducer  35   
     A rigid but light material such as Nickel Titanium alloy such as nitinol, a super-elastic alloy manufactured from nickel and titanium is especially suited for fabrication of the jaws. Other suitable materials are stainless steel and formed plastic. The jaws are manufactured from the selected material by forming the material in the required shape and heat-treating the material to fix that shape without further deformation. 
     As depicted in  FIG. 2 b   , an embodiment of this invention features two jaws  41 ,  42  of unequal length, where, for example, a first jaw  41  is longer than a second jaw  42 . It is envisioned that different combinations of jaws would be made available so that a surgeon may choose the combination best suited for the operation to be performed. With jaws of unequal length, the shape of any one jaw can be manipulated to increase the collection ability of the pouch by increasing the arc available from that pincer. This arrangement allows the surgeon to exert a force along a line nearly parallel to the introducer  35 . The surgeon may attempt tissue removal at several sites along a line extending parallel to the pusher rod axis a. It can be appreciated that this aspect of the invention would facilitate scraping or avulsing of tissue adhering to a surrounding region. 
     Pouch Detail 
     This invention incorporates a pouch  20  bordered by a mouth  25  as depicted in  FIG. 3 . In general, Nylon or other plastics are suitable materials for fabrication of the pouch. In one embodiment, a two-layer configuration is used, one layer being a polyurethane laminate and the other rip-stop nylon. 
     A toggle  50 , the function of which is described infra, is admitted through the aperture  28  described supra formed in a region of the collar of the pouch such that when the pouch is attached to the jaws the aperture is positioned in close spatial relationship to the distal end of the sleeve  35 . The pouch further comprises a means for receiving a drawstring  89  such that the drawstring receiving means also serve as the jaw receiving means of the pouch, such means being the channel  23  formed by the collar  27 . The drawstring traverses the channel  23  such that the ends of the string  89  protrude from the proximal end of the sleeve  35  so as to provide the surgeon a means for providing tension to the drawstring. This string facilitates closing of the mouth of the pouch after the jaws are retracted from the channel  23  formed in the hem  27  of the pouch, and prior to the tissue sample being retrieved from the surgical site. 
       FIG. 1 a    is a cross-sectional view of  FIG. 1  along the line 1a-1a. It depicts the pusher rod  30  and two ends of the drawstring  89  as they are received in the introducer tube  35 . In an alternative embodiment, one end of the string  89  is attached to the pouch hem at the orifice  28  and the other end of the string is threaded through the channel  23  so as to exit from the collar through the orifice  28  and be threaded through the introducer tube  35 . In both embodiments, the open end of the drawstring  89  are received by the handle housing  72  (see  FIG. 1 ). 
     In an exemplary embodiment, the fabric comprising the pouch is a rip-stop nylon cross-stitched polyamide  66  material with a polyurethane laminate, with thickness between 0.0035 and 0.0045 inches. This material has substantially higher puncture strength than other commonly used tissue pouch materials. For example, when a 5 mm diameter full radius rounded probe was used to simulate a 5 mm laparoscopic instrument, the puncture strength of the material was measured using a Chatilon 50 pound test device. A force in excess of 26 pounds was required to puncture the material. 
     The hem  27  of the pouch is radio-frequency welded to form the channel  23  which receives the jaws  41  and  42  so that the pouch depends from the jaws forming a continuous, homogeneous, perforation-free substrate with a stitch-free seam. This arrangement provides a tear-resistant construction that prevents the pouch from being accidentally ripped away from the jaws. The side  21  and bottom  22  of the pouch are also radio-frequency welded thus providing a totally impermeable pouch. 
     As shown in  FIG. 8 a   , the invented device is delivered with the bag somewhat extended out of the introducer tube. The surgeon or the surgical suite personnel can pre-treat the bag with antibiotic, or saline solution, or some sort of solution that would optimize use of the bag in the body. For example, treating the bag with sterile saline solution dulls the surface of the bag making it less shiny so as to reduce glare by surgical lights also inserted within the body. Aside from the saline pretreatment, the bag can also be swabbed with antibiotic, or some sort of a marker that fluoresces when it contacts cancerous materials (or one may use fluorescent DNA tags where the DNA is complementary to whatever protein coat is associated with the target cancer tissue). 
     The fabric of the pouch can be selected to hang downwardly from the jaws, per the effect of gravity, as noted supra. Alternatively, the pouch comprises a stiffer material so as to retain its shape, volume and depth, no matter how it is positioned relative to gravity. 
     Toggle Structure and Function. 
     Another feature of the invention is a toggle and handle arrangement where the pusher rod handle must be in a predetermined alignment with the proximal end of the introducer handle in order to allow full protrusion, and therefore release, of the toggle from the introducer tube. This toggle/handle arrangement prevents accidental separation of the pouch from the jaws  41 ,  42 . This full protrusion/handle arrangement also provides a movement of the toggle that is also controlled by a locking means for preventing rotation of the bag relative to the introducer tube. (See discussion infra related to  FIGS. 7 and 8 .) 
     Toggle mechanisms are depicted in  FIGS. 4 a  through 4 i   . One embodiment of the toggle means is depicted in  FIGS. 4 a  and 4 b   . It comprises a two-position post  50  that rotates about a pivot  51 , such that the toggle post  50  swings through the arc “S” in the plane of the Figure, a plane orthogonal to the plane defined by the elongated substrates  41 ,  42  forming the hanger or jaws. The pivot  51  is situated intermediate the distal and proximal ends of the rod and in rotatable communication with the rod.  FIG. 4 i    is a detail view of the toggle mechanism depicted in  FIG. 4 a    with the toggle  50  entering the channel  23  through the aperture  28  and the jaws  41 ,  42  entering the channel  23  through the apertures  29 . 
       FIGS. 4 c  and 4 d    are profile and top views of an alternative embodiment for the toggle  50 . As shown in  FIG. 4 d   , the toggle has a U-shape with the open end of the U pivoting around the pivot point  51 .  FIG. 4 h    is a detail view of the toggle mechanism depicted in  FIG. 4 c   , in an alternative configuration to that depicted in  FIG. 4 i   , with the toggle  50  and the jaws  41 ,  42  entering the channel  23  through the same aperture  28 . 
       FIGS. 4 e , 4 f , and 4 g    depict yet another alternative embodiment for the toggle mechanism. The toggle mechanism is provided by a bendable metal or plastic curved member  49  that is either removably attached to or integrally molded to the distal end  31  of the pusher rod  30  (the member  49  may be in the shape of a loop or a tongue or may comprise one or more antennae). In  FIG. 4 e    the member is depicted in a bent configuration after it has been threaded through the toggle-receiving aperture  28 : in this configuration the toggle is bent half-a-circle and made to lie parallel to the pusher rod  30  as it is received in the introducer tube  35 , with the tip  63  of the member pointing toward to the handle of the introducer.  FIG. 4 f    depicts the situation when the pusher rod  30  has been pushed in the direction marked by the arrow I and the pouch is deployed so that the member  49  is in position  49   b  as it is about to disengage from the hem of the pouch.  FIG. 4 g    depicts the situation when the rod is pulled back in the direction marked by the arrow J and the member  49  is in its relaxed position  49   a  and disengaged from the hem of the pouch. As noted supra, the toggle and jaws are both mounted in the rod such that the surgeon pulls the pusher rod and jaws into the introducer tube, the toggle slides completely out of the bag aperture  28  ( FIG. 4 g   ). Continued pulling of the rod causes the jaws  41 ,  42  to pull out of the channel  23  and through the introducer tube at the same time as the rod. In  FIG. 4 h    the member  49  is depicted in a bent configuration so as to lie parallel and proximal to the jaws  41 ,  42  and constrained to be engaged in the aperture  28  in the channel  23  in the hem of the pouch. This embodiment has the advantage of comprising no external spring and no detachable parts. 
     As shown in  FIG. 6 a   , when the device is assembled, a distal end  67  of the post  50  is inserted in the aperture  28  (optionally defined by a grommet) at the same time as the jaws  41 ,  42  are inserted in the channel  23  defined by the hem  27 . This is designated the toggle “open” position (Depicted as “O” in  FIG. 4 a   ). The handle  71  of the pusher rod  30  is designed so that when it completely nests within the handle saddle  83  of the introducer  35 , in a male/female configuration, the distal end of the rod emerges from the distal end of the introducer  35  to a distally biased position so as to allow the toggle free range of motion along a 180 degree arc such that the free end of the toggle extends away from the handle  71  and toward the pouch  20  (see discussion infra related to  FIGS. 7 c  and 8 a  through 8 d   ). In one embodiment of the invention, the toggle post  50  will not exit from the introducer tube until the handle  71  and the handle housing  72  are aligned in a complementary configuration depicted in  FIG. 7 a   , the handle being provided with markings to serve as a visual cue to the surgeon that the device is now configured to detach the pouch from the pusher rod assembly (see discussion infra related to  FIGS. 7 c  and 8 e   ). When the handle and the handle housing are so positioned, the two interlock and the toggle  50  will exit from the distal end of the introducer and from the slit  28  and bias to a position intermediate the closed “C” and open “O” positions coming to rest against the distal end  31  of the pusher rod  30 . 
     Toggle length is chosen to ensure that it cannot rotate through the aforementioned arc unless the pusher rod  30  it is fully extended (distally) from the introducer tube  35 . While still constrained by the interior surfaces of the introducer tube, the toggle remains in an undeployed position and in frictional engagement with the interior surface of the introducer tube. This constraint serves as a means to prevent the jaw-forming elongated substrates  41 ,  42  from accidentally being retracted from the pouch hem, retreating into the introducer, and causing a premature detachment of the pouch from the pusher rod. 
     When the surgeon is ready to remove the pouch from the body (for example, after the pouch is loaded with tissue), the pusher rod  30  is fully extended distally so as to extend through the introducer tube and therefore clear the toggle from the confines of the interior surface of the introducer tube  35 . At that point, the spring bias toggle flips to an intermediate retaining configuration, between positions “O” and “C” by still remaining protruding through the eyelet  28  formed on the proximal side of the pouch collar. A definitive tug away from the body cavity by the surgeon on the handle of the pusher rod causes the toggle post to engage the distal lip of the distal end of the introducer tube, thereby forcing the toggle to pivot about the pusher rod and toward the pouch such that the toggle end extends in a direction (designated as position “O”) away from the surgeon. 
     This configuration, with the toggle pointing away from the surgeon, enables the toggle to slide out of (or otherwise disengage from) the eyelet  28  as the pusher rod  30  is pulled in a proximal direction to retract further yet out of the introducer. Concomitantly, the hanger  40  comprised of the jaws  41 ,  42 , (heretofore described as attached to the distal end of the pusher rod  30 ), are pulled out of the channel  23  and retreat with the toggle post into the introducer. These actions leave the pouch  20  behind. 
     Once the pouch hanger  40  and pusher rod  30  are fully extracted from the introducer tube  35 , the surgeon closes the pouch by pulling on ends of the drawstring  89 . As noted supra, inasmuch as the drawstring resides in the channel  23  defined by the pouch hem, i.e., the same channel in which the jaws are positioned. Pulling on the drawstring protruding from the proximal positioned end  39  of the introducer tube  35  serves to constrict and ultimately close the pouch opening to assure containment of the tissue residing in the pouch during extrication of the pouch from the body. Further pulling of the pouch drawstring draws the closed pouch into the distal end of the cannula. 
     The spring-biased action of the toggle (from position “O” to position “C”) disclosed above may be achieved by a helical spring  53  affixed to the pivot  51  and the post  50  (See  FIGS. 2 a  through 2 d   ) so as to cause the post  50  to spring back towards the introducer end  39  (i.e. towards the surgeon) once the post is released from the pouch hem  27 . In still another embodiment, a torsion spring  52  may be affixed to the pivot  51  and the post  50  (See  FIG. 4 b   ) so as to cause the post  50  to spring back towards the introducer distal end  36 . In another alternative embodiment of the toggle mechanism the toggle  50  constitutes a blunt end of a torsion spring  52  attached to the pusher rod  30 . 
     In another embodiment, the toggle mechanism is actuated without the use of an external spring. As shown in  FIG. 5 a   , the post  50  may be chosen to be of a diameter such that there is a frictional interaction between the pusher rod  30  assembly and the inside wall  37  of the introducer. Thus there is an outward, radially-directed pressure (i.e. a pressure applied in a direction perpendicular to and away from the longitudinal axis a of the introducer) on the introducer as the pusher rod and toggle are pushed through it. Elastic radial contraction of the introducer  35  when the toggle post  50  is released causes the toggle post to rotate proximally, (i.e., toward the proximal or surgeon end of the introducer (i.e. such that the post distal end  67  points away from the pouch hanger or fork  40  as indicated by the arrow T in  FIG. 5 b   ). 
     As the toggle post exits the introducer  35 , there is a configuration depicted in  FIG. 5 b    where the point  61 , nearest to the pivot  51 , has already exited from the introducer  35 , while the diametrically opposite point  62  is still in the introducer where it experiences an inward radial force F due to the compression of the introducer  35 . This unbalanced force F results in a clockwise torque about the pivot  51  and a consequent clockwise rotation of the post towards the end  36  of the introducer  35  as shown by the arrow T. This rotation is also facilitated by the drag on the device due to the surrounding body tissue, an effect that can be enhanced if the distal end  60  of the post  50  that exits from the hem  27  is cut at angle with respect to the length of the post. (See  FIG. 5 c   ). In this embodiment, the proximal end  60  of the toggle post  50  terminates in a plane that is at angle of roughly 45 degrees to the longitudinal axis a of the pusher rod  30  as the toggle comes to rest against the distal end  39  of the introducer. The toggle must be such that the distance between the pivot point  51  and the point  62  on the toggle distal end  67  is such that the toggle can reenter the introducer sleeve when the pusher rod is retracted. 
     Of course, one may combine two or more of the spring-back mechanisms suggested above. 
     In another alternative embodiment, the toggle is bent at a point  57  intermediate the pivot point  51  and the distal end  67  projecting above the plane defined by the pouch hanger or pincer fork  40  (in the opposite direction of the pouch  20 ) (See  FIG. 4 i   ). 
     The toggle may be manufactured from steel, from the same material as the pincers, or from any other suitable material. Also, the toggle may be manufactured as part of the of the pusher rod mechanism, comprising a bent loop within the introducer tube that acts as a toggle. 
       FIGS. 6 a  through 6 d    illustrate in further detail the function of the toggle mechanism.  FIG. 6 a    shows the toggle post  50  engaged with the pouch  20  wherein the distal end  67  is nested in the hem  27  through the aperture  28 . It must be appreciated that the hem/aperture/toggle orientation is obtained by means of tension provided by the toggle post  50 . As soon as the toggle post is withdrawn from the hem  27 , and especially when the pouch is filled with a tissue specimen, the slit  28  is displaced with respect to the toggle post  50  and the pusher rod  30  (See  FIG. 6 b   ).  FIG. 6 c    shows the toggle post at 90 degrees to the pusher rod  30 .  FIG. 6 d    shows the toggle post coming to rest against the introducer  35 . When the final tissue sample has been collected the pusher rod  30  is retracted into the introducer  35 , so that the above sequence is reversed from  FIGS. 6 d  to 6 c  to 6 b   . At this juncture, one cannot reinsert the toggle post  50  into the slit  28  of the hem  27  because the post and the slit are now misaligned. Further retraction of the pusher rod  30  toward the surgeon brings the toggle post  50  against, but not inside, the hem  27  so that the toggle post now detaches the pouch from the pouch hanger or fork  40 . 
     While the preceding discussion emphasized operation of the device with the toggle received in a channel  23  in the hem of the pouch through an orifice  28  when the device is first inserted in the patient, this is not necessary for effective operation of the device. The functions of the toggle can be equally well performed without the toggle having been inserted in the orifice  28  or with the toggle having been accidentally disengaged from the hem of the pouch before deployment of the device. 
     Handle Detail 
       FIGS. 7 a  and 7 b    are schematic front and back views of an exemplary embodiment of a handle assembly  70  that can be advantageously used with the invented device and  FIGS. 8 a  through 8 f    illustrate the use of this handle assembly. The handle assembly comprises a handle  71  that is rigidly attached to the pusher rod  30  and a housing  72  that is rigidly attached to the introducer tube  35 , so as to render the housing  72  in rotatable communication with the handle  71  through a bore  73  traversing the housing. The housing  72  also comprises a groove  79  adapted to receive a portion  78  of the handle  71  in a male-female configuration. The assembly  70  has a front face depicted in  FIG. 7 a    comprising a first surface  76  of the handle  71  defining a protrusion  75  aligned with the axis a of the pusher rod  30 . A first surface  80  of the housing  72  comprises a slot  83  or saddle adapted to slidably receive the protrusion  75 . The first surface  80  of the housing  72  further comprises a slit  74  adapted to frictionally receive the ends of the drawstring  89 . Also, the first surface  76  of the handle  71  comprises a marking  91 , such as the word “UP” to distinguish it from the back face of the handle depicted in  FIG. 7 b   . Stripes  121  on the first surface of the housing come into alignment with stripes  122  on the protrusion when the handle is fully inserted and this serves as a visual indicator to the surgeon that the handle is fully inserted indeed. 
       FIG. 7 b    depicts the back face of the handle assembly, showing that the second surface  82  of the housing  72  comprises a marking  99  such as a semi-circular arrow  99  together with a directive such as “TO UNLOAD”. 
       FIG. 7 c    depicts the orientation of the handle assembly when the device is inserted in the patient. The surgeon inserts the device with the first surface  76  of the handle  71  coplanar to the second surface  82  of the housing  72  so that the protrusion  75  abuts the proximal edge  84  of the housing  72  and the pusher rod  30  is prevented from fully exiting the introducer tube  35 . 
     Operation of the Device 
       FIGS. 8 a  through 8 f    illustrate the operation of the device. In  FIGS. 8 a  through 8 d    the first surface  76  of the handle  71  is facing in the same direction as the second surface  82  of the housing  72  so that the protrusion  75  abuts the proximal edge  84  of the housing (See  FIG. 7 c   ). In  FIG. 8 a    the pouch  20  is shown extending from the distal end of the introducer tube  35 . This allows for pretreatment. In  FIG. 8 b    the pouch is shown being withdrawn into the introducer tube  35 . Throughout this sequence the arrow  95  indicates the direction in which the handle  71  is moved. In  FIG. 8 c    the device is introduced through a trocar port  93  connected to a patient. The surgeon places the pouch into position, pushes the handle towards the housing and the pouch deploys automatically when the handle  71  comes into contact with the housing  72  so that the protrusion  75  abuts the housing  72  (see  FIG. 7 c   ).  FIG. 8 d    depicts the surgeon placing a tissue sample  96  into the pouch. Then the surgeon rotates the housing 180 degrees as directed by the semi-circular arrow  99  while keeping the handle immobile in the “up” position. In  FIG. 8 e    the surgeon inserts the protrusion  75  into the slot  83  so as to cause the rod to extend to its distal-most position. (See  FIG. 8 e     2  showing the protrusion  75  fully received in the slot  83  with the stripes  121  on the housing brought into alignment with the stripes  122  on the protrusion.) Finally, the surgeon pulls the handle  72 , pusher rod  30 , and pouch hanger or fork assembly  40  from the pouch and the introducer tube  35  as shown in the detail  FIG. 8 e     1 . 
     In  FIG. 8 f    the mouth of the pouch is closed by pulling on the draw string and then the surgeon removes the introducer tube  35  and the trocar  93  outside the patient and brings the mouth of the pouch to outside the abdomen. The tissue is removed from the pouch and then the pouch is removed from inside the patient. 
     Outside the Patient (Proximal) Portion of the Device 
     The proximal end of the device is designed so as to aid the surgeon in ascertaining the position and functioning of the distal end of the device. In one embodiment, the plane defined by the fully deployed hanger  40  (comprised of the elongated substrates) is fixed in relation to the handle  71  orientation. This requires the elongated substrates  41 ,  42 , to be rigidly attached to the distal end of the pusher rod  30 , so as not to be in rotatable communication with the rod. As such, the handle  71 , pusher rod  30 , and hanger  40  move as a single unit when the rod is rotated, and/or slid in and out of the introducer tube  35 .  FIGS. 7 a  and 7 b    depict means to indicate to the surgeon the orientation of the pouch. 
     The introducer tube  35  comprises at its proximal end  39  a handle housing  72  adapted to receive a handle  71  in two different configurations. 
       FIG. 7 c    depicts the orientation of the handle assembly when the device is inserted in the patient. The surgeon inserts the device with the front face  76  of the handle  71  facing in the same direction as the back face  82  of the housing  72  so that the protrusion  75  abuts the proximal edge  84  of the housing  72 . 
     When the handle  71  is fully inserted in the housing  72  ( FIGS. 7 a  and 7 b   ) the pusher rod  30  and the introducer  35  are locked relative to each other, such that one is not rotating about or within the other. It is in this fully nested position that the toggle emerges from the distal end of the introducer tube, is released from the pouch  20 , and springs back to its “closed” or “C” position. Pulling of the pusher rod in a proximal direction (i.e., toward the surgeon or operator of the device) causes the toggle arm to engage with the distal lip or periphery of the introducer tube, thereby forcing the toggle to reset to a pouch-releasing configuration (position “O”) as proximally directed force on the pusher rod” is maintained. 
     The toggle also facilitates loading of the device by acting on the pouch and pulling it into the introducer tube. The device is loaded by the scrub nurse or assistant and delivered to the surgeon in a loaded condition with the pusher and toggle positioned in the bag aperture  28  and also in the introducer tube. The surgeon or an attendant now pulls on the handle of the introducer and pulls the pusher, the toggle, and the pouch into the introducer tube. The tight fit between the pusher handle and the introducer handle prevents accidental unloading of the toggle from the distal end of the introducer tube. The toggle not only facilitates deployment of the pouch but allows loading of the pouch into the introducer tube without using long tails to push the pouch or complicated structures to which the pouch is attached. 
     While the invention has been described in the foregoing with reference to details of the illustrated embodiment, these details are not intended to limit the scope of the invention as defined in the appended claims.