referring now to the drawings , and specifically to fig1 - 4 , the pubovaginal sling device 20 of the present invention can be made of any of number of biologically compatible materials and provided to surgeons in various dimensions for surgical implantation in human subjects 60 . in preferred embodiments , the width and length of the sling 20 may be varied in preparation for a surgical procedure by removing a portion or portions of uniformly sized sling devices 20 provided commercially by a manufacturer of the sling device 20 . the preferred sling 20 is used to provide urethral and pelvic support to female urogenital organs , preferably the urethra and / or bladder neck in an attempt to restore urinary continence in incontinent women . the device 20 works in a manner similar to that of other sling devices known in the art . however , the present device 20 provides a loop support 40 around the urethra 62 , preferably the mid - urethra and / or bladder neck , which is not provided by other sling devices . in preferred embodiments , made from processed animal tissues , the present sling device 20 provides superior strength and flexibility , such that superior is postoperative results can be anticipated . the pubovaginal sling 20 of the present invention includes a center portion 22 and first and second side portions 24 and 26 , respectively . the center portion includes a slot 28 through which the first side portion or looping limb 24 may pass to form a loop 40 in the elongated sling device or strip 20 . in preferred embodiments of the present device made of processed animal tissues , and the respective side portions may include an additional piece or pieces of processed animal tissue which are joined to other portions of the elongated strip by any of a number of well known attachment methods , preferably by securing the attached piece or pieces to the other portions of the elongated strip 20 using sutures 29 as shown in fig3 . by joining separate pieces of processed animal tissue in this way , it is possible to obtain a longer strip than might otherwise be available when made from any particular material from which the strip may be made . where the length of available materials is not as limited as it may be in certain cases when utilizing processed animal tissues , the preferred sling device 20 will not have the multiple pieces or sutures joining multiple pieces together . in this particular case , therefore , the embodiment of the sling 20 shown in fig3 is illustrative only , and is not meant to limit the present invention to sling devices having multiple pieces joined together , as opposed to a single elongated strip as illustrated in fig1 and 3 . in many preferred embodiments the sling device 20 will be a single piece of material . in circumstances where sufficiently elongated processed animal tissues are available , preferred sling devices of the present invention made of such materials will be without separate pieces or suture lines . referring now especially to fig3 in preferred embodiments , the center portion 22 has a length a 1 , and a width b . in such embodiments the sling device 20 will have a length c and a variable thickness d . the center portion 22 will preferably have a main section 31 having a length a 1c and shoulder sections 32a and 32b , having lengths a 1a and a 1b , interconnecting the main section 31 to the side portions 24 and 26 on either side of the main section 31 , respectively . the slot 28 has a length e which is greater than the width f of the looping limb 24 , such that the looping limb 24 can pass easily through slot 28 to form a loop support 40 which can encircle a urethra 62 of a subject and enable the attending surgeon to lift or elevate the urethra 62 , and preferably the bladder neck 64 as well , by placing appropriate tension on the sling 20 when it is implanted within the subject . the respective shoulders 32a and 32b preferably have a variable width which increases as the shoulders 32a and 32b extend from the respective side portions 24 and 26 toward the main section 31 . the length of the respective side portions 24 and 26 are denoted by dimension lines a 2 and a 3 respectively . as is evident from reviewing the sling 20 illustrated in fig3 the width f of the looping limb 24 is less than the length e of the slot 28 , which is , in turn , less than the greatest width b of the center portion 22 . it will be appreciated that it is unnecessary for the various dimensions of the sling 20 and its various sections or parts to be constant and that these dimensions may vary even in a single embodiment . it will also be appreciated , that the length c of the sling 20 will be greater than the greatest width b of the sling 20 , and the greatest width b of the sling 20 will be greater than the greatest thickness d of the sling 20 . in preferred embodiments , the respective shoulders 32a and 32b will have a variable width which increases as the measurement is made moving from the end proximate the respective side portion 24 or 26 to the main section 31 , or from a width the same or similar to the width f of the side portion 24 or 26 to the width b of the main section 31 . referring now also to fig5 and 6 , the preferred sling device 20 is preferably used to provide an anchored urethral loop 40 around the urethra 62 and / or bladder neck 64 of the subject . the suggested surgical procedure is intended to provide correction in the form of support for the urethra 62 and bladder neck 64 by elevation and repositioning of the urethra 62 and bladder neck 64 as shown in fig6 . the position of the urethra 62 prior to the procedure is illustrated in fig5 . in fig6 it will be noted that the urethra 62 is lifted or elevated and is curved upward somewhat more than depicted in fig5 prior to descending further away from the bladder 66 and bladder neck 64 . preferred embodiments of the pubovaginal sling device 20 of the present invention will have the following dimensions : ( 1 ) length : c = 530 mm ; a 1 = 70 mm ; a 2 = 230 mm ; a 3 = 230 mm ; a 1c = 30 ; a 1b = 25 mm ; a 1a = 15 mm ; and e = 15 mm ( length of the slot 28 ); ( 2 ) width : f = 10 mm ; b = 25 mm ; and ( 3 ) thickness : d = 10 mm . the thickness may be from about 0 . 1 to about 2 . 0 mm or more ; preferably about 0 . 1 to about 1 . 0 mm ; and may in some cases vary somewhat , especially in material from animal sources . it will be appreciated that the dimensions of the sling 20 will vary , however , and in many cases , vary proportionately . the length of the urethra 62 in women is believed to vary from about 10 mm to about 50 mm , preferably about 15 mm to about 40 mm . for some subjects a sling 20 having a small width b of 15 mm may be desirable . such slings 20 will be made proportionally smaller in all of the width and length dimensions set forth herein above , but the thickness d will not be varied substantially , if at all . similarly , if the width b is set at 20 mm , the other length and width dimensions will be sized up or down proportionately . the width b can be from about 5 mm to about 40 mm , preferably about 10 mm to about 30 mm , more preferably about 15 mm to about 25 mm . obviously , any of these dimensions can vary as desired at the time of manufacture or use . the surgical procedure is generally initiated by applying some form of anesthesia to the female patient 60 . although local anesthesia is preferred , the operation can be conducted under general anesthesia . a foley urethra catheter is generally inserted preoperatively into the bladder 66 of the subject through the urethra 62 . the procedure is initiated by making two horizontal incisions ; a horizontal abdominal incision just above the pubis 68 , and a vaginal incision , in the vaginal orifice , on the upper surface of the vaginal wall approximately 0 . 5 to about 1 cm below the external urethral meatus . blunt dissection of the pubourethral ligaments , the urethra 62 and the bladder neck 64 from the anterior vaginal wall and surrounding tissues will then proceed . the horizontal incision is made just above the pubis 68 across the midline and dissected down to the abdominal rectus sheath 70 , preferably insuring that all of the subcutaneous fat is removed from the sheath 70 . left lateral blunt dissection then proceeds from the vaginal incision up through the retro pubic space , through the abdominal rectus sheath 70 into the supra pubic incision , followed by right lateral blunt dissection from the vaginal incision up through the retro pubic space through the abdominal rectus sheath 70 into the supra pubic incision . the second side portion or left limb 26 of the preformed sling device 20 is then fed through the vaginal incision , the recto pubic tunnel created by the left lateral blunt dissection , and through the abdominal rectus sheath 70 to the supra pubic incision . the right limb or looping limb 24 is then fed through the vaginal incision , around the dissected urethra 62 , through the slot 28 in the center portion 22 of the sling 20 , up through the retro pubic tunnel created by the right lateral blunt dissection , through the rectus sheath 70 and through the supra pubic incision . care is then taken to properly size the loop support 40 created when the looping limb 24 is passed through the slot 28 , and sutures 38 are then placed through the overlapping segments of the sling 20 on the opposite lateral sides of the loop support 40 to ensure that the loop support 40 does not diminish in cross - sectional diameter during its residence within the body 60 . the respective side portions or limbs 24 and 26 are overlapped supra over the abdominal rectus sheath 70 ; tension is placed upon the left and right limbs 26 and 24 by bringing them together over the sheath 70 until the urethra 62 is raised or elevated to the desired position providing appropriate support to the urethra 62 , and an appropriate amount of tension is placed upon the urethra 62 so that it will remain in the desired position . the respective limbs 26 and 24 are then clamped in place , preferably with a blunt tissue forceps or the like , and fixated using any of a number of means which are well known in the surgical arts , preferably a &# 34 ; running mattress &# 34 ; suture or such other fixation mechanism as may be desired . the vaginal and abdominal incisions are subsequently closed in a conventional manner . the schematic illustration provided in fig1 diagrammatically depicts the sling support device 20 in place following implantation , encircling the urethra , and passing behind the pubic bone 68 to the rectus abdominis fixation or suture 36 above the pubic bone 68 supra the abdominal rectus sheath 70 . the urethra / bladder neck loop 40 preferably has sutures 38 fixating the loop 40 on either lateral side as shown in fig4 . in the embodiment shown in fig3 the sling device 70 includes a length of a non - absorbable suture material 25 in each of the ends 27a and 27b of the respective right and left side portions or limbs 24 and 26 . in preferred embodiments , the suture material 25 will be engaged with suture needles 29 which can be fed through the vaginal incision , and ultimately up to the supra abdominal incision . the respective limbs or side portions 26 and 24 can then be drawn up through the abdominal incision and subsequently fixed together . alternatively , a blunt forceps may be used to reach through the abdominal incision to grasp the suture material 25 , and preferably , the suture needle 29 , to draw the suture material 25 and the respective limb or side portion 24 or 26 up from the vaginal incision . when the suture material 25 is present , the left limb 26 is drawn up through the abdominal incision first . the suture material 25 engaged with the right limb or looping limb 24 is then fed around the urethra 62 and through the slot 28 , and the right limb 24 is subsequently drawn around the urethra 62 and through the slot 28 . a blunt forceps may then be used to draw the suture material 25 and the looping limb 24 up through the abdominal incision . sutures 38 to secure the urethral / bladder neck loop 40 may then be secured and the rectus abdominis fixation 36 may be created as previously described , after appropriate tension is placed upon the urethra 62 . in preferred embodiments , the non - absorbable suture material used for suture material 25 , sutures 38 and the preferred running mattress sutures or the like in the rectus abdominis fixation 36 will be a non - absorbable suture material which is well known in the art such as polyester , preferably dacron ® polyester , expanded polytetrafluoroethylene ( eptfe ), preferably gore - tex ®, polypropylene , braided silk , or the like . as stated above , the material used to manufacture the slings 20 of the present inventions include synthetic polymers , processed animal tissues , combination thereof , and the like . the synthetic polymers include polymers such as polytetrafluoroethylene ( ptfe ), preferably teflon ®; expanded polytetrafluoroethylene ( eptfe ), preferably gore - tex ®, polyesters or polyethylene terephthalates , preferably dacron ® polyester , silicone elastomers , and the like . processed animal tissues of the present invention include processed porcine , bovine , ovine , and equine tissues , human tissues and the like . human tissue is preferably obtained from human cadavers when used at all . these tissues are preferably selected from the group consisting of tendons , ligaments and serous membranes or fibro serous tissues , including smooth fibrous connective tissues . preferred fibro serous tissues include dura mater , pericardium , peritoneum , tunica vaginalis and dermas . processed animal tissues are preferably chemically cross - linked animal tissues prepared by any of a number of methods which are well known in the art . some of these methods are disclosed in the following documents which are hereby incorporated herein by reference : u . s . pat . no . 4 , 456 , 589 to holman et al . ; r . c . peterson et al ., dynamic internal compliance measurements of fresh and fixed arteries , asaio transactions , 1990 , p . m766 - m769 ; y . murayama et al ., reduction of antigenicity and immunogenicity of xenograpfts by a new cross - linking reagent , asaio trans ., 1988 , p . 546 - 549 ; t . okoshi et al ., long - term results of a new anti - thrombogenic cardiac wall substitute , asaio trans ., 1989 , p . 391 ; y . tomizawa et al ., development of a small - caliber vascular graft with antithromogenicity induced by extreme hydrophilicity , asaio trans ., 1988 , p . 644 ; e . imamura et al ., epoxy compounds as a new cross - linking agent for porcine aortic leaflets : subcutaneous implant studies in rats , j . card . surg . 1989 , p . 50 ; and y . noishiki et al ., development of a small caliber vascular graft by a new cross - linking method incorporating slow heparin release collagen and natural tissue compliance ; asaio trans ., 1986 , p . 114 . preferred tissue cross - linking agents include glutaraldehyde , glutaraldehyde starch , dialdehyde , dialdehyde starch , and the like , and epoxy or polyexpoxy compounds ( pc ) such as for example polyethelene glycol , diglycidyl ether , glycerol polyglycidyl ether , polyglycerol polyglycidyl ether , sorbitol polyglycidyl ether , and the like . radiation may also be used to cross - link tissues from these animal sources . animal tissues used are preferably carefully selected from tissues available from government regulated slaughter houses where animals are known to be free of transmittable agents such as bovine spongiform encephalopathies ( bse ) and the like . prior to treatment with chemical cross - linking agents , these tissues are preferably dehydrated with a dehydrating fluid , such as ethyl alcohol or the like , to allow for improved penetration of the chemical cross - linking agent or &# 34 ; tanning agent &# 34 ; which cross - links collagen in the tissues to both make the tissue stronger and reduce the antigenicity of the tissue . other agents such as pepsin can also be used to further reduce antigenicity . the cross - linking of the tissues used in the present invention is preferably accomplished using one or more of the following treatment agents : glutaraldehyde , dialdehyde , glutaraldehyde starch , dialdehyde starch , an epoxy compound or ionizing radiation . certain processes ( such as heat , radiation or ph change ) or agents such as halogens , enzymes , organic solvents , detergents , sodium hydroxide , hydrochloric acid , sodium hypochlorite or hydrogen peroxide ) may be used to inactivate viruses with and without protein coats or to destroy bse agent infectivity during the manufacturing process . the tissue may also be treated with a highly volatile chemical such as for example propylene oxide , to assist with the sterilization of the tissue . sterilization may be accomplished using one or more of the following treatments : glutaraldehyde , alcohol , propylene oxide or irradiation sterilization . the treatment of the tissue , with a combination of these materials and processes , can both cross - link the tissue and render the tissue sterile for implantation . combinations of synthetic polymers and processed animal tissues can also be used in slings 20 of the present invention . these combinations may include spliced strips 20 having a combination of parts , including parts made of synthetic polymers and of processed animal tissues . such combinations also include materials which include both synthetic polymers and animal cells which are treated so as to cross - link the collagen or other commonly antigenic fibers in the animal cells . for example , materials can be used which are like the collagen coated ultrafine polyester mesh ( cufp ) of the type disclosed by t . okoski et al ., asaio trans ., 1989 , p . 391 ; the contents of which are hereby incorporated herein by reference . the form of the strip of tissue allows for a minimally invasive vaginal procedure for suspending the bladder neck of the urethra . the procedure used with the strip will simplify implantation and reduce the risks associated with more invasive surgical procedures . problems associated with suture erosion through the tissue and the potential for bone infections associated with the use of bone anchors to suspend the sling will also be reduced . processed pericardial tissue has both a smooth and rough surface . it is the intention of the inventors that the rough surface of the tissue will be adjacent to the tissue surrounding the urethra . this will allow for adhesion of this surface to the tissue surrounding the urethra , thus securing it in place and not allow it to slide or wear the surface of the urethra . it is the further intention of the inventors to increase the intra - urethral pressure through the use of an equal circumferential pressure . this is applied by looping the flat strip of tissue around the urethra rather than kinking the urethra , as commonly done in prior art procedures . this equal circumferential pressure will be applied , preferably on the lower half of the urethra , over a larger portion of the urethral length than is common with present suture suspensions . it will be appreciated that the sling 20 may be longer , shorter , wider or thinner than illustrated in the present drawings . it is to be further understood that even though numerous characteristics and advantages of various embodiments of the present invention have been set forth in the foregoing description , together with details of the structure and function of various embodiments of the invention , this disclosure is illustrative only and changes may be made in detail , especially in matters of shape , size and arrangement of parts , within the principles of the present invention , to the full extent indicated by the broad general meaning of the terms in which the appended claims are expressed .
a sling device for surgical implantation into human recipient to support the urethra , the sling including an elongated strip of supple material . the elongated strip has a center portion , opposite first and second side portions , and a slot passing through the center portion , through which one of the side portions can pass , thereby forming a loop in the elongated strip . the material is a biological acceptable material for implantation into the human recipient , preferably selected from the group consisting of synthetic polymers , processed animal tissues , and combination thereof . a method of reducing the incidence of involuntary urination or restoring urinary continence in an incontinent human subject is also disclosed , including the steps of providing a sling device of the type previously described and surgically implanting the sling device in the human subject so that the urethra is biased upward so as to elevate the urethra .