Abstract:
A device for surgically repairing and reinforcing a hernia includes a hernia prosthesis having a substantially planar base portion and an overlay portion, each formed from a biocompatible material. The overlay portion is peripherally attached to the base portion to define a pocket to receive a surgical instrument or a surgeon&#39;s finger for placing the prosthesis within the human body. The pocket may be formed with releasable stitching to enable it to be flattened or removed after placement and may contain a resilient member that urges the prosthesis into a flat configuration.

Description:
FIELD OF THE INVENTION  
         [0001]    The present invention relates to a hernia repair prosthesis, and more particularly to a substantially planar surgical mesh prosthesis for bridging a hernia.  
         BACKGROUND OF THE INVENTION  
         [0002]    Surgically implantable mesh patches for the repair of inguinal and other abdominal wall hernias are commonly used and provide tension free repairs by bridging the hernia defect. Patches of this type constitute a structural support which decreases recurrence rates and because they do not require the displacement of tissues to cover the hernia, decrease postoperative discomfort. Frequently, prostheses of this type are sutured in place, i.e., proximate to the periphery of the patch. An alternative to suturing the prosthesis is to insert it into the properitoneal space. U.S. Pat. No. 5,916,225 to Kugel discloses a hernia prosthesis having a resilient ring made of synthetic material, such as nylon, polypropylene or polyester enclosed within a pocket formed by opposing planar segments of surgical mesh that are attached together to encapsulate the ring. A slit is provided in one of the planar segments to permit the surgeon to insert a finger therein in order to push the prosthesis through an incision in the abdominal wall into the properitoneal space and across the hernia. The resilient ring urges the pocket into a deployed planar configuration, i.e., to straighten the wrinkling and folding of the pocket that occurs in the course of its placement. The disadvantages associated with the device disclosed in U.S. Pat. No. 5,916,225 are that each layer of mesh is stiff and dense, such that the combination of two layers and the resilient ring constitutes a rigid, high mass prosthesis which tends to cause discomfort and resists conformance to the patient&#39;s anatomy.  
           [0003]    It is therefore an object of the present invention to provide a hernia repair prosthesis for use in a surgical hernia repair as generally described in U.S. Pat. No. 5,916,225 but that has lower mass, and greater flexibility.  
         SUMMARY OF THE INVENTION  
         [0004]    The problems and disadvantages associated with conventional hernia prostheses and their associated methods of use are overcome by the present invention which includes a hernia prosthesis having a substantially planar base portion and overlay portion, each formed from a biocompatible material. The overlay portion is attached to the base portion in substantially parallel juxtaposition thereto and along an attachment junction that defines an open ended pocket therebetween. The open-ended pocket receives an elongated object such as a surgical instrument or a surgeon&#39;s finger for placing the prosthesis within the human body. The pocket captures an end of the elongated object when it is urged in a first direction to induce the displacement of the prosthesis in the first direction and slidably releases the elongated object when it is moved in the opposite direction. 
       
    
    
     BRIEF DESCRIPTION OF THE FIGURES  
       [0005]    For a better understanding of the present invention, reference is made to the following detailed description of several exemplary embodiments considered in conjunction with the accompanying drawings, in which:  
         [0006]    [0006]FIG. 1 is a plan view of a hernia prosthesis in accordance with a first exemplary embodiment of the present invention.  
         [0007]    [0007]FIG. 2 is a diagrammatic, perspective view of the prosthesis of FIG. 1 in a partially assembled state;  
         [0008]    [0008]FIG. 3 is a diagrammatic, perspective view of a prosthesis in accordance with a second exemplary embodiment of the present invention;  
         [0009]    [0009]FIG. 4 is a is plan view of a hernia prosthesis in accordance with a third exemplary embodiment of the present invention;  
         [0010]    [0010]FIG. 5 is a is a perspective view of the prosthesis of FIG. 4, at an intermediate stage of folding;  
         [0011]    [0011]FIG. 6 is a plan view of a hernia prosthesis in accordance with a fourth exemplary embodiment of the present invention;  
         [0012]    [0012]FIG. 7 is a plan view of a elastic stretcher element used in the prosthesis of FIG. 6.  
         [0013]    [0013]FIG. 8 is a perspective view of a prostheses in accordance with a fifth exemplary embodiment of the present invention;  
         [0014]    [0014]FIG. 9 is a diagrammatic view of the disassembling of the prosthesis of FIG. 8; and  
         [0015]    [0015]FIG. 10 is a perspective view of the prosthesis of FIG. 8 with the stitching unloosened to illustrate a releasable stitching arrangement. 
     
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS  
       [0016]    [0016]FIGS. 1 and 2 show a prosthesis  10  in accordance with the present invention having a generally planar base portion  12  and an overlay portion  14 , folded thereover to form a pocket  15 . The pocket  15  is dimensioned to receive the finger of a surgeon, as shall be explained below. The prosthesis  10  may be formed from any biologically compatible, flexible, porous medical textile, such as those commonly used for reinforcing and occluding tissue defects. Knitted polypropylene monofilament mesh fabrics such as those available from Ethicon, Inc. under the Prolene, Vicryl and Panacryl trademarks may be utilized to fabricate the prosthesis  10 . Other suitable mesh materials are available under the Marlex, Dacron, Teflon, Merselene and Polysorb (produced by United States Surgical Corporation) trademarks. Tissue regeneration may be induced through the use of absorbable materials in fabricating the prosthesis  10 . It is preferred that the mesh used to form the prosthesis  10  be simultaneously flexible and have a low mass with a high porosity/open area ratio. These objectives are met by a material described in a copending application entitled KNITTED SURGICAL MESH, application Ser. No. 09/723,854 filed Nov. 28, 2000 and owned by the assignee of the present application, such application being incorporated herein by reference. The foregoing material is commercially available from Ethicon, Inc. under the trademark PROLENE*SOFT.  
         [0017]    The prosthesis  10  preferably has visible alternating stripes  16 ,  18  or other indicia to aid in identifying the orientation of the prosthesis  10  when it is being placed in the body of the patient. While a circular prosthesis  10  may be used in certain circumstances, in other situations an oblong or oval shape, having a greater extent in one dimension is preferred. Accordingly, the stripes  16 ,  18  may be used to orient an elongated prosthesis  10  at the surgical site, e.g., by presenting a readily appreciable indicia of orientation. The stripes  16 ,  18  may be provided by utilizing a pattern of different color fibers in the textile from which the prosthesis  10  is made. Alternatively, stripes or other indicia may be printed on or otherwise applied to the prosthesis  10 .  
         [0018]    The overlay portion  14  has a complementary shape to that of the base  12 , such that when the overlay portion  14  is folded along fold line  20 , the respective outer peripheral edges  24 ,  26  align and may be bonded by adhesives, plastic welding, interweaving or by being stitched together by thread  22 . The stitching of the thread  22  may be interlocking to prevent the removal of the thread  22  or the thread may be removable by pulling on a free end thereof to unravel removable stitching, as further described below. The use of removable stitching permits the thread  22  to be removed after placement of the prosthesis at the hernia repair site and the subsequent unfolding and flattening of the overlay portion  14  to a position substantially co-planar with the base  12 . In this manner, the thickness and rigidity of the prosthesis  10  can be reduced and the extent thereof can be increased by the unfolding, i.e., by the length of the overlay portion  14 . The extent of overlap of the overlay portion  14 , relative to the base  12 , when in the folded configuration, is illustrated in FIG. 2 by dotted line  28 .  
         [0019]    [0019]FIG. 3 shows a prosthesis  110  in accordance with an alternative embodiment of the present invention, in which the overlay portion  114  has a generally U-shaped configuration, with a central scallop  130 . Elements illustrated in the alternative embodiments shown in FIGS.  3 - 10  which correspond to elements described above with respect to FIGS. 1 and 2 have been designated by corresponding reference numerals increased by 100, 200, 300 and 400, respectively. The position of the overlay portion  114  on the base  112  when folded along fold line  120  is illustrated by dotted profile line  128 . The scallop  130  reduces the mass and rigidity of the overlay portion  114  while preserving a structure that will capture an inserted finger when urged in the forward and sideways directions to allow positioning of the prosthesis  110 . In addition, the scallop increases the degree of freedom of the inserted finger. For example, while a straight-edged overlay portion  14  like that shown in FIG. 1 (see line  28 ) may restrain the inserted finger from bending at the first and/or second joint, the U-shaped overlay portion  130  would permit bending of the finger at these joints.  
         [0020]    [0020]FIGS. 4 and 5 illustrate an alternative prosthesis  210  that is formed from a substantially rectangular piece of surgical mesh. As before, the overlay portion  214  is folded at line  220  over the base  212 . In order to form a generally pointed configuration where the prosthesis is narrower at the fold  220  than at the free end  213  of the overlay  214 , folds  232 ,  234  each having at least two panels  236 ,  238 , extend inwardly between overlay portion  214  and the base  212 . The pointed shape of the folded prosthesis  210  aids in introducing it through the patient&#39;s tissues to the hernia site. As in the previous embodiments, the overlay portion  214  may be either fixedly or removably bonded to the base  212 . Because the shape of the prosthesis  210  is realized by folding, if the bonding is removable, the prosthesis  210  may be unfolded to a generally rectangular planar shape, thereby minimizing rigidity and maximizing surface area.  
         [0021]    [0021]FIGS. 6 and 7 show an alternative embodiment of the present invention having a prosthesis  310  such as that disclosed above in reference to FIGS.  1 - 5  but with a resilient spreader element  340  inserted between overlay portion  314  and base portion  312 . The resilient member  340  may be a simple U-shaped spring made from stainless steel, super elastic steel, such as, NiTi NOL, or plastic, such as, nylon. The resilient member  340  is deformable to allow the prosthesis  310  to be placed proximate to the hernia. Once in position, the resilient member  340  urges the prosthesis  310  into a generally planar configuration extending over the hernia defect. The resilient member  340  shown in FIGS. 6 and 7 has a central loop  342  to increase its flexibility and to provide a means for grasping the resilient member  340 , i.e., the loop  342  can receive the finger of a surgeon inserted therein. The resilient member  340  may also be provided with end loops  348 ,  350  through which the resilient member  340  may be attached to the prosthesis  310  by stitching, i.e., in those circumstances when the surgeon would prefer the resilient member  340  to remain in the prosthesis  310  at the end of the procedure. Alternatively, the resilient member  340  may be removable, either being tucked between the overlay portion  314  and the base portion  312  or held to the prosthesis  310  by removable stitching. When the prosthesis  310  has been placed and the resilient member  340  has accomplished its purpose of spreading the prosthesis over the hernia site, then the resilient member  340  may be removed to decrease the mass and rigidity of the prosthesis  310  and any associated discomfort. During removal, the end loops  348 ,  350  prevent the ends of the arms  344 ,  346  of the resilient member  340  from piercing or snagging on the adjacent tissues. As shown in FIG. 6, the end loops  348 ,  350  may extend beyond the overlay  314 . In this manner, the resilient member  340  exerts its flattening effect over a larger surface area of the prosthesis  310 , i.e., beyond overlay flap  314 .  
         [0022]    FIGS.  8 - 10  show a prosthesis  410  in accordance with the present invention and having an overall configuration similar to that of the forgoing embodiments depicted in FIGS.  1 - 7 , but having a separate overlay portion  414  that is entirely detachable from the base portion  412 . More particularly, the overlay  414  is a separate piece of surgical mesh that is held to the base  412  by thread  422  that stitches the overlay  414  to the base  412  in a releasable manner. FIG. 9 illustrates that when the thread  422  is pulled to release the stitching holding the overlay  414  to the base  412 , the thread  422 , upon further pulling, may be used to remove the overlay from its position relative to the base  412 . During the placement of the prosthesis  410 , the surgeon&#39;s finger F may be held over the base  412  to retain it in a selected position whereupon the thread  422  may be pulled releasing and removing the overlay portion  414  from the base portion  412 . In this manner, the overlay portion  414  may be utilized in the process of placing the prosthesis  410  into position, i.e., by forming a gripping pocket and then detached to decrease the rigidity and mass of the prosthesis  410  to a single layer of mesh. i.e., the base portion  412 .  
         [0023]    [0023]FIG. 10 shows one exemplary method of implementing a removable stitching arrangement to releasably retain the overlay  414  in association with the base  412 . More particularly, the thread  422  is passed through a first hole H 1  in the overlay portion  414  and then through a corresponding hole H 2  in the base portion  412 . (While the overlay  414  and base  412  are shown spaced apart in FIG. 10, this is for the purpose of illustration only. In forming the prosthesis  410 , they would be juxtaposed.) An elongated release loop  452  is formed and the distal end  454  of the release loop  452  is then passed through hole H 3  and H 4 . The distal end  454  is then looped over the release loop  452  to form a gripper loop  456  and then reenters hole H 4  and then hole H 5 . The distal end  454  is then passed to hole H 7  to form an overlay retainer loop  458  (shown in dotted lines proximate hole H 7 ). This pattern is repeated multiple times until the terminal end  454  reaches the terminal hole Ht where it is tied off against the overlay portion  414 . When the proximal end  460  of the thread  422  is pulled, the release loop  452  is pulled through the gripper loops  456 , allowing them to be pulled through the even numbered holes H 4 , H 6 , etc. This allows the retainer loops  458  to be pulled from the odd numbered holes H 5 , H 7 , etc. After all the gripper and retainer loops  456 ,  458  are pulled out, the overlay  414  is pulled free of the base  412  by the thread  422 , as shown in FIG. 9.  
         [0024]    The prosthesis  10  may be used in the surgical repair of a hernia in accordance with the procedure described in U.S. Pat. No. 5,916,225 to Kugel, such patent being incorporated herein for its teaching relative to this procedure, which is also known in the art. Briefly, the repair of an inguinal hernia is made in accordance with this known procedure utilizing the present invention by inserting the prosthesis  10 ,  110 ,  210 ,  310  or  410  through a relatively small, oblique incision, e.g., 2 to 3 centimeters in length, made in the patient&#39;s abdomen above the internal ring location of the inguinal hernia. To prepare for insertion of the prosthesis, the surgeon performs a dissection through the oblique incision deep into the patient&#39;s pro-peritoneal space, using the muscle splitting technique. This dissection process results in a pocket in the pro-peritoneal space that can receive the prosthesis  10 . The prosthesis  10  (or  210 ,  310  or  410 ) of the present invention can be placed over the surgeon&#39;s finger or fingers, i.e., with the finger(s) in the pocket  15 . The prosthesis  10  is then inserted into the cavity previously surgically formed in the properitoneal space. If the prosthesis is inadvertently folded in the course of placement in the body, it can be unfolded by the surgeon&#39;s finger(s) or under the influence of the resilient member  340 . This unfolding operation is aided by the overlay portion  14  which provides a means for the surgeon to push the distal edge at fold line  20  forward, as well as to push against the sides (proximate to the peripheral edges  24 ,  26 ) of the prosthesis  10 . This allows the surgeon to position the prosthesis  10  to the best advantage for supporting the herniated tissue. In the event that a resilient member  340  is utilized, it may be removed after placement of the prosthesis  310 . Furthermore, if removable stitching is employed, (formed by thread  422 ), the overlay portion  414  may be unfolded (as in the embodiments of FIGS.  1 - 5 ) or removed (as in the embodiment of FIGS.  8 - 10 ). While the foregoing procedure of placing the prosthesis  10  utilizes the surgeon&#39;s finger(s) directly, one or more surgical instruments could be employed to position and flatten the prosthesis. For example, one or a pair of steel rods can be used in the same manner as the surgeon&#39;s finger(s). The pair of rods may be independent or conjoined at a pivot point, such that the spacing of the distal ends thereof may be controlled by the spacing of the proximal ends.  
         [0025]    It should be understood that the embodiments described herein are merely exemplary and that a person skilled in the art may make many variations and modifications without departing from the spirit and scope of the invention as defined in the appended claims. Accordingly, all such variations and modifications are intended to be included within the scope of the invention as defined in the appended claims. For example, while the embodiments described above utilize an overlay portion  14  that is smaller in surface area than the base portion  12  and therefore only partially covers the base portion  12 , the present invention could be carried out by a prosthesis that utilizes base and overlay portions that are of equal or substantially equal dimensions.