Abstract:
A device and method for retrieving specimens from a body cavity during minimally invasive surgery uses a specimen pouch that is deployable from an introducer inserted into the body cavity through a predefined passage such as a cannula. The specimen pouch includes a resilient band that causes the specimen pouch to open automatically and remain open after removal from the introducer. Once removed from the introducer, the specimen pouch is free-standing with no attachment to the introducer or to an externally operated closure mechanism. Closure and removal are accomplished using a conventional forceps or other instrument to grasp a portion of the band and withdraw the band and the opening of the pouch into the introducer. The pouch is configured so that withdrawal of the band into the introducer causes the material around the opening of the pouch to gather and seal the opening.

Description:
BACKGROUND OF THE INVENTION 
     The present invention relates broadly to surgical instruments and more particularly to methods and a device for collecting and removing specimens from a body cavity during surgery. 
     During surgery, there is often a need for the collection and removal of tissue specimens, such as organs or other material from a body cavity of the patient. These materials must generally be isolated to prevent contamination of the body cavity during removal. In minimally invasive surgery where access to the body cavity is restricted to vary small incisions, isolation and removal of specimens can be difficult. This is particularly so because such surgery often involves insufflation of the body cavity requiring that the access incisions be sealed against leakage. 
     The problem of specimen retrieval during minimally invasive surgery has typically been addressed by the introduction of a closable, flaccid bag or pouch into the body cavity. This pouch is typically deployed through a cannula and includes an arrangement for remotely closing the bag once a specimen has been deposited therein. Once closed, the pouch may be withdrawn through the cannula. 
     Several problems have been presented by previous specimen pouch designs, particularly with respect to their closure mechanisms. Because a specimen pouch must be closed prior to removal from the body cavity, its closure mechanism must be, in part, external to the patient&#39;s body. The mechanism often takes the form of a tether, drawstring or other flexible member that is threaded around the bag opening and through the cannula. Closure is typically accomplished by retraction of this member which results in the cinching of the pouch. With most such designs, the pouch must remain attached to this mechanism or to the cannula used to introduce the pouch. In either case, the introducer cannula must remain in place, typically with a portion of the closure mechanism disposed therein. This not only prevents the cannula from being used for other instruments, it restricts the movement of the pouch within the body cavity. 
     Another problem results from the manner in which the closure mechanism draws the pouch closed. Closure is usually accomplished using a form of cinch or noose wherein a drawstring or belt is drawn through a sleeve disposed around the opening of the pouch. This method often results in irregular bunching of the material around the pouch access opening which, in turn, can result in incomplete closure and an unacceptable risk of contamination. Further, nooses and other mechanisms used for closure require the drawing of a single strand or belt through essentially the complete circumference of a sleeve surrounding the bag opening. In addition to compounding the bunching problem, this results in an increase in the force required to draw the strand or belt through the sleeve as the bag nears complete closure. 
     Other specimen bag designs have attempted to solve the closure problem by using collapsible spring members or other relatively complex mechanisms that may require the use of specialized instruments to assist in closure. 
     There is accordingly a need for a specimen retrieval device that provides secure isolation of collected specimens using a low complexity, remotely manipulated closure mechanism that is separable from the collection device. 
     SUMMARY OF THE INVENTION 
     It is accordingly an object of the present invention to provide an improved specimen retrieval device for use in minimally invasive surgery. 
     It is a further object of the present invention to provide an improved specimen retrieval device that includes a specimen pouch stored in an introducer and insertable into a body cavity through a cannula. 
     It is also an object of the present invention to provide a specimen pouch that is initially stored in a storage configuration and automatically opens to deployed configuration when removed from storage. 
     It is yet another object of the present invention to provide a specimen pouch that, once deployed, is separate and independent from the other elements of the invention used to facilitate insertion, closure and retrieval of the pouch. 
     Another object of the present invention is to provide a specimen pouch having a closure mechanism that is operable using conventional surgical instruments. 
     It is also an object of the present invention to provide a specimen pouch closure mechanism that securely closes the pouch while reducing the risk of leakage due to bunching of the material surrounding the bag opening. 
     It is a further object of the present invention to provide a method for collecting and removing specimens from a body cavity using a specimen retrieval device according to the present invention. 
     To those ends, a specimen retrieval device according to the present invention for use within a body cavity during surgery includes an introducer having a proximal end and a distal end and defining a lumen therethrough. The introducer is configured and dimensioned for at least partial introduction into the body cavity through a predefined passageway. The specimen retrieval device further includes a pouch having an access opening defined therein. This pouch is collapsible for storage within the lumen and expandable upon removal from the lumen. The pouch has a first sleeve formed along a first portion of the pouch adjacent the opening and a second sleeve formed along a second portion of the pouch adjacent the opening. These sleeves are configured to define spacings between the sleeves. The specimen retrieval device also includes a resilient band having a first band portion slidably disposed within the first sleeve and a second band portion slidably disposed within the second sleeve. The band is configured to be collapsible for storage within the lumen along with the pouch. The band is also configured to bias the pouch in an open configuration when the pouch is removed from the lumen. 
     The band of a specimen retrieval device according to the present invention preferably includes at least one grasping tab projecting radially outward from the band. The at least one grasping tab is disposed in one of the spacings and forms a grasping surface for acquisition of the band by a surgical instrument. The band preferably includes first and second grasping tabs disposed in a space relationship along the band and dividing the band into first and second segments intermediate the grasping tabs. The first segment includes the first band portion and the second segment includes the second band portion. 
     A specimen retrieval device according to the present invention preferably further includes an arrangement for sealing a surgical instrument inserted into the lumen for interaction with the pouch. The arrangement for sealing is preferably attached to the proximal end of the introducer and preferably includes a septum valve. 
     A method for retrieval of specimens from a body cavity through a predefined passage according to the present invention includes providing a specimen retrieval device. The specimen retrieval device includes an introducer having a proximal end and a distal end and a specimen pouch defining an access opening. The specimen pouch has a first sleeve formed along a first portion of the pouch adjacent the opening and a second sleeve formed along a second portion of the pouch adjacent the opening. The specimen pouch also has a resilient band having a first band portion slidably disposed within the first sleeve and a second band portion slidably disposed within the second sleeve. The band is configured to bias the specimen pouch in an open configuration and includes at least one grasping tab. The specimen pouch is provided in a collapsed configuration and is removably disposed within the introducer adjacent the distal end. 
     The method for retrieval of specimens further includes the step of inserting the introducer into the predefined passage so that the distal end of the introducer extends through the cannula into the body cavity. The method further includes removing the specimen pouch from the introducer within the body cavity and placing material in the specimen pouch for removal from the body cavity. Also included in the method are the steps of acquiring the band using a surgical instrument, withdrawing the band into the introducer through the distal end, thereby gathering the sleeves and closing the opening of the pouch, and withdrawing the introducer and the specimen pouch through the predefined passage. 
     In the method for retrieval of specimens according to the present invention, the step of removing the specimen pouch from the introducer preferably includes the step of inserting an instrument into the proximal end of the introducer. The step of removing the specimen pouch also further includes the step of pushing the specimen pouch out of the distal end of the introducer thereby releasing the band to open the specimen pouch and allowing the specimen pouch to assume a deployed configuration within the body cavity. 
     In a preferred embodiment of the method for retrieval of specimens according to the present invention, the specimen pouch is disposed within the introducer so that one of the at least one grasping tab is disposed adjacent the distal end. In this embodiment, the step of removing the specimen pouch from the introducer preferably includes the steps of inserting a grasping element of a grasping instrument through a second predefined passage into the body cavity, acquiring one of the at least one grasping tab of the band using the grasping element, and pulling the specimen pouch out of the distal end of the introducer using the grasping instrument. This releases the band to open the specimen pouch and allows the specimen pouch to assume a deployed configuration within the body cavity. The step of removing the specimen pouch also further includes the step of releasing the at least one grasping tab. 
     The step of acquiring the band using a surgical instrument preferably includes the steps of inserting a grasping element of the surgical instrument through the introducer into the body cavity and acquiring one of the at least one grasping tab of the band using the grasping element. The step of withdrawing the band into the introducer preferably includes withdrawing the grasping element into the distal end of the introducer so that the first and second segments of the band make contact with the distal end of the introducer. The step of withdrawing preferably further includes further withdrawing the grasping element toward the proximal end of the introducer, thereby forcing the first and second segments to deform and be pulled into the distal end of the introducer. This causes the distal end of the introducer to make contact with the first and second sleeves, thereby causing the first and second sleeves to slide along the first and second segments away from the one of the at least one grasping tab. This in turn causes the opening of the specimen pouch to close. The step of withdrawing the band also preferably includes still further withdrawing the grasping element toward the proximal end of the introducer, thereby drawing the sleeves into the introducer. 
     By the above, the present invention provides an effective device and method for the collection and removal of tissue or other material during surgery. The device offers a simple solution to the problem of leakage due to bunching of material around the bag opening. Further the specimen pouch of the present invention is not tied to its introducer or external closure mechanism in any way while in use for specimen collection. The pouch uses a simple closure mechanism that is easy to use and requires no specialized grasping instruments. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     FIG. 1 is a side cutaway diagrammatic view of a specimen retrieval device according to a preferred embodiment of the present invention; 
     FIG. 2 is a side cutaway diagrammatic view of a deployed pouch assembly of the specimen retrieval device illustrated in FIG. 1; 
     FIG. 3 is a diagrammatic top view of the pouch assembly illustrated in FIG. 2; 
     FIG. 4 is a cross-sectional diagrammatic view of the specimen retrieval device taken at  4 — 4  of FIG. 1; 
     FIG. 5 is a cutaway perspective view of the specimen retrieval device illustrated in FIG. 1; 
     FIG. 6 is a cutaway perspective view of the specimen retrieval device illustrated in FIG. 1 in a deployed configuration; 
     FIG. 7 is a cutaway perspective view of the specimen retrieval device illustrated in FIG. 1 illustrating withdrawal by a grasping instrument; 
     FIG. 8 is a cutaway perspective view of the specimen retrieval device illustrated in FIG. 1 illustrating withdrawal by a grasping instrument; 
     FIG. 9 is a cutaway side view of the specimen retrieval device illustrated in FIG. 1 illustrating withdrawal by a grasping instrument; and 
     FIG. 10 is a cutaway side view of the specimen retrieval device illustrated in FIG. 1 in a retrieval configuration. 
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT 
     Turning now to the drawings and more particularly to FIG. 1, a specimen retrieval device according to the preferred embodiment of the present invention is illustrated generally at  10  and includes a pouch assembly  20 , an introducer  40  and a valve assembly  50 . The specimen retrieval device  10  is intended for use as a repository for material to be removed from a body cavity during minimally invasive surgery. The pouch assembly  20  is initially stored in the introducer  40 , which may be partially inserted into the body cavity through a cannula (not shown). The pouch assembly is then removed from the introducer  40  within the body cavity. 
     The pouch assembly  20  includes a pouch  22  and a band  30  that are collapsible for storage within the introducer  40  and that automatically deploy upon removal from the introducer  40 . The deployed pouch assembly  20  is then available for use by the surgeon. The pouch assembly  20  requires no tether or other connection to the introducer  40  or any other instruments disposed within or without the body cavity. For removal, the pouch assembly  20  may be closed and secured to the introducer or other cannula using any suitable grasping instrument as will be described in detail hereafter. The introducer  40  or cannula may then be withdrawn along with the secured pouch assembly  20 . 
     Turning now to FIGS. 2 and 3, the pouch assembly  20  includes a pouch  22  and a band  30 . The pouch  22  is formed from two pliant, generally planar walls  23 , which are preferably formed of a thin, urethane film. These walls  23  are substantially rectangular and are joined along three edges  14 ,  16 ,  18  to form an envelope with an opening  25  surrounded by the remaining free edges  28 . It will be understood by those having ordinary skill in the art that other envelope shapes may be used such as tapered or hourglass shapes without departing from the spirit of the present invention. The pouch  22  may alternatively be configured as a three dimensional shape such as a cone or prism. It will also be understood that the joined edges  14 ,  16 ,  18  of the walls  23  may be welded, fused or bonded in any suitable fashion. 
     A sleeve  26  is formed from a generally rectangular portion of planar urethane material  27  attached to each free edge  28  of each wall  23 . This material  27  is preferably integrally formed with the wall  23 , but may also be welded, fused or bonded to the wall  23 . The sleeve  26  is formed by looping the material  27  over a portion  38  of the band  30 , which will be described in detail hereafter, and joining the material  27  to the wall  23  adjacent the previously free edge  28 , thereby slidably disposing the band portion  38  within the sleeve  26 . The ends  29  of sleeve  26  are formed so that they have a concave profile as shown in FIG.  2 . The concave portions form a space  24  between the two sleeves  26  for grasping of the band  30  or for grasping tabs connected to the band  30  to extend between the sleeves  26 . Alternatively, the sleeves  28  can be formed so that they do not extend along the entire length of the free wall edges  28 , thus leaving a gap where the two edges  28  come together. It should be noted that FIG. 2 illustrates only one side of the pouch  22  and therefore illustrates only one of the two walls  23  and one of the two sleeves  26 . It will be understood by those having ordinary skill in the art that the second wall  23  and the second sleeve  26  are mirror images of the illustrated wall  23  and sleeve  26 . 
     The band  30  is formed with first and second grasping tabs  32  and  34  attached to its outer circumference at diametrically opposed locations as shown in FIG.  3 . As described above and as shown in FIGS. 2 and 3, each sleeve  26  is formed so that a portion of the band  30  is slidably disposed within the sleeve  26  between the two grasping tabs  32 ,  34 . The concave configuration of the sleeve ends  29  provides a space  24  between the sleeves through which the grasping tabs  32 ,  34  extend. The band  30  and grasping tabs  32 ,  34  are preferably integrally formed of polypropylene. the material and dimensions for the band  30  are selected so that it is collapsible for storage within the introducer  40  along with the pouch  22  yet has sufficient resilience and stiffness so that the band  30  will cause the pouch  22  to open and remain open when the pouch assembly  20  is removed from the introducer  40 . The band is preferably ring-shaped for simplicity, but it will be understood by those skilled in the art that other band shapes are possible. As can be seen in FIG. 4, the cross section of the portions  38  of the band  30  disposed through the sleeves  44  in this preferred embodiment are substantially circular. For a desired deployed opening of approximately 2.5 inches in diameter, a polypropylene band  30  having an outside ring diameter of 2.5 inches and a circular cross-sectional diameter of 0.103 inches provides adequate resilience and stiffness. It will be understood by those having skill in the art that the present invention may include larger or smaller pouches  22  requiring correspondingly larger or smaller bands  30 . It will also be understood that other cross-sectional configurations are possible such as a rectangular cross-section, which results in a belt-like band  30 . 
     Returning to FIG. 1, the introducer  40  is formed as a thin-walled tube  46  preferably of a substantially transparent medical grade plastic. The introducer  40  has a proximal end  43  and a distal end  44  and defines a lumen  42  extending therebetween. The tube  46  is sized so that it may be inserted into a conventional cannula and will accommodate the pouch assembly  20  when in its storage configuration. 
     The valve assembly  50  is mounted to the proximal end of the introducer  40  and includes a housing  52  defining a passage  54  therethrough and an arrangement  56  for sealing around an instrument inserted into the introducer  40  through the passage  54 . The sealing arrangement  56  preferably includes a septum valve  58  or its equivalent. The septum valve  58  is formed as a generally pliant disc and has a central aperture  59 . The central aperture  59  has a diameter that is less than the diameter of the smallest surgical instrument that will be inserted through the valve assembly  50  into the introducer  40 . When an instrument is inserted through the valve assembly  50 , the aperture  59  stretches to allow passage of the instrument while maintaining a seal around the body of the instrument. The valve assembly  50  thus allows the sealed insertion of a grasping instrument into the introducer  40  for engagement with the pouch assembly  20  for deployment or retrieval of the pouch assembly  20  as will be described in more detail hereafter. 
     As illustrated in FIGS. 2,  3 ,  4  and  9 , the pouch assembly  20  has three primary configurations including a storage configuration, a deployed configuration and a retrieval configuration. In the storage configuration, the band  30  is collapsed so that the sleeves  26  and the portions  38  of the band  30  disposed therethrough are brought into close proximity as shown in FIG.  4 . The pouch  22  is rolled or folded in a manner to facilitate deployment and is positioned beneath the collapsed band  30 , also as shown in FIG.  4 . The pouch assembly  20  is positioned within the lumen  42  adjacent the distal end  44  of the introducer  40  so that the second tab  34  extends out of the introducer  40 . The extension of the second tab  34  outside the lumen  42  of the introducer  40  facilitates the grasping of the second tab  34  for removal of the pouch assembly  20  during surgery as will be described in more detail hereafter. It will be appreciated that the transparent nature of the introducer  40  facilitates the loading of the pouch assembly  20  into the introducer  40  as well as inspection of the assembled retrieval device  10  to assure that the pouch assembly  20  is properly installed prior to use. 
     The deployed configuration is illustrated in FIGS. 2 and 3. In this configuration, the band  30  biases the opening  25  into a generally elliptical form approaching the circular shape that would be assumed by the  36  if unconstrained by the sleeves  26 . The pouch  22  is freely suspended from the band  30 . 
     In the retrieval configuration, illustrated in FIG. 10, the band  30  has been withdrawn into the introducer  40  so that its opposite sides are in close proximity as in the storage configuration. In this configuration, however, the sleeves  26  have been gathered against the second grasping tab  34 , thereby sealing the opening  25  of the pouch  22 , and have been retracted into the distal end  44  of the introducer  40 . The remainder of the pouch  22  and any specimens contained therein remain outside of the introducer  40 . 
     In operation, the specimen retrieval device  10  is used by first disposing the pouch assembly  20  in the lumen  42  of the introducer  40  with the pouch assembly  20  in its storage configuration. The distal end  44  of the introducer  40  is inserted through a cannula that has been previously inserted into an incision to permit communication with a body cavity. The introducer  40  is positioned so that its distal end  44  is outside the cannula within the body cavity. 
     Once the introducer  40  is in position, the pouch assembly  20  may be removed from the introducer  40  using one of two methods. In the first method, the pouch assembly  20  is pushed out of the introducer  40  using any blunt instrument that may be inserted through the valve assembly  50  and into the lumen  42  of the introducer  40  and that is long enough to reach the distal end  44  of the introducer  40 . The method is accomplished by simply inserting the blunt instrument (not shown) through the valve assembly  50  into the lumen  42  until it makes contact with the pouch assembly  20 . Once having made contact, the instrument is used to push the pouch assembly  20  out of the distal end  44  of the introducer  40 . 
     The second manner in which the pouch assembly  20  may be removed from the introducer  40  involves the use of a grasping instrument  60  inserted through a second cannula  64  as shown in FIG.  5 . The grasping element  62  of this instrument is inserted into the body cavity through the second cannula  64  to grasp the second tab  34  extending from the distal end  44  of the introducer  40 . Once the second tab  34  has been grasped, the grasping instrument is retracted toward the cannula  64 , thereby pulling the pouch assembly  20  out of the introducer  44 . It will be understood by those having ordinary skill in the art that the extension of the second tab  34  outside the lumen  42  eases the task of locating and grasping the tab  34 . However, it will also be understood that some grasping instruments could be used that would allow the second tab  34  to be grasped even if disposed entirely within the introducer  40 . With these instruments, the second tab  34  need only be adjacent the distal end of the introducer  40 . The transparent nature of the introducer  40  is of particular value when the tab  34  does not extend outside the introducer  40 . 
     Upon removal of the pouch assembly  20  by either method, the band  30  causes the pouch  22  to open as the band  30  or a portion thereof is removed from the introducer  40 . The resilience of the urethane film used to form the pouch  22  is sufficient to cause the pouch  22  to at least partially unroll or unfold. Biological or other material may then be deposited into the pouch  22 . If the pouch  22  has not entirely unrolled or unfolded, the deposition of material into the pouch  22  will cause it to fully deploy. 
     Turning now to FIGS. 6 through 9, when the pouch assembly  20  is ready for removal, the grasping element  62  of a grasping instrument  60  is inserted through the valve assembly  50  and the introducer  40  into the body cavity. The grasping element  62  is then used to grasp the tab  32  as shown in FIG.  6 . The grasping element  62  is then withdrawn into the lumen  42  of the introducer  40  until the band  30  makes contact with the distal end  44  of the introducer  40  as illustrated in FIG.  7 . As shown in FIG. 8, the grasping element  62  is then further withdrawn into the lumen  42  thereby forcing a portion of the band  30  to deform from its elliptical shape and enter the lumen  42 . As the band  30  is further drawn into the lumen  42 , the distal end  44  of the introducer  40  makes contact with the ends of the sleeves  26  and causes them to draw back along the circumference of the band  30 . Importantly, the two sleeves  26  are drawn back independently in a symmetrical manner. This provides a smoother, more reliable gathering of the material surrounding the opening  25  of the pouch  22  than may be obtained using a single continuous sleeve or by withdrawing one side of a band having its other side fixed to the introducer. As the band  30  is yet further drawn into the lumen  42 , the band  30  is forced into its retrieval configuration and the sleeves  26  are gathered against the tab  34 . This effectively closes and seals the opening  25  of the pouch  22  as shown in FIG.  9 . The remainder of the band  30  and the gathered sleeves  26  are then drawn through the distal end  44  into the lumen  42 , thereby placing the device  10  in its retrieval configuration as shown in FIG.  10 . The introducer  40  and the pouch assembly  20  may then be withdrawn through the cannula. In its retrieval configuration, the pouch  22  is securely closed thus assuring that the specimens enclosed therein cannot escape or be contaminated. 
     In the method recited above, the introducer  40  may remain in place within the cannula throughout the surgery. However, because the pouch assembly is entirely independent once deployed, the introducer  40  may be removed, making the cannula available for other surgical use. For removal of the pouch assembly  20 , the introducer  40  may be reinserted into the cannula and the band  30  retracted into the introducer  40  as previously described. Alternatively, a grasping instrument may be inserted through any available cannula having a distal end of suitable configuration for causing the band  30  to deform to allow the end of the cannula to make contact with the sleeves  26  and gather them together at the second tab  34 . To facilitate this approach, a valve assembly similar to the illustrated valve assembly  50  would be attached to the cannula. The introducer  40  could then be inserted through the valve assembly into the cannula and removed from the cannula after deployment of the pouch assembly  20  without loss of body fluids or insufflation pressure. Using this approach, the specimen retrieval device does not require its own valve assembly  50 . 
     The specimen retrieval device  10  of the present invention provides significant advantages over previous devices in its reliability, simplicity and ease of use. Of particular importance is the ease with which the pouch  22  is closed without the use of a tether. The band  30  is configured to deform in such a way as it is withdrawn into the introducer  40  that its opposing side portions  38  are close together and essentially parallel to the common axis of symmetry of the band  30  and the pouch  22  at the entrance to the lumen  42 . This reduces the resistance to withdrawal of the band  30  through the sleeves  26 . The round cross-section of the band  30  further reduces this resistance by reducing the sliding friction of the sleeves  26  over the band  30 . The sleeves  26  are configured to be withdrawn in parallel along the axis of symmetry through the band  30 . Simultaneously gathering the sleeves  26  on both sides in this manner results in regular, controlled gathering of the material surrounding the opening  25  and assures secure closure of the pouch  22 . 
     Although a tether is not required for closure of the pouch  22 , a retrieval tether (not shown) may be attached to the band  30  and threaded through the introducer  40  to ensure that the location of the pouch assembly  20  within the body cavity may be ascertained or controlled. A retrieval tether could also be used to assist in the process of removal by allowing the surgeon to pull the pouch assembly  20  into a position that facilitates the grasping of the band  30 . 
     By the above, the present invention is shown to provide a low complexity, easily used device for secure removal of tissue or other specimens during surgery. 
     It will therefore be readily understood by those persons skilled in the art that the present invention is susceptible of a broad utility and application. Many embodiments and adaptations of the present invention other than those herein described, as well as many variations, modifications and equivalent arrangements, will be apparent from or reasonably suggested by the present invention and the foregoing description thereof, without departing from the substance or scope of the present invention. Accordingly, while the present invention has been described herein in detail in relation to its preferred embodiment, it is to be understood that this disclosure is only illustrative and exemplary of the present invention and is made merely for purposes of providing a full and enabling disclosure of the invention. The foregoing disclosure is not intended or to be construed to limit the present invention or otherwise to exclude any such other embodiments, adaptations, variations, modifications and equivalent arrangements, the present invention being limited only by the claims appended hereto and the equivalents thereof.