Abstract:
The present invention refers to a prosthesis ( 1 ) to be used for surgical therapy of female urinary incontinence and urogenital prolapse. Said prosthesis comprises a synthetic or biologic non-reabsorbable or partially reabsorbable mesh ( 9 ) and positioning means originating from said mesh ( 9 ) and comprising self-locking absorbable or non-absorbable threads ( 3, 3′ ), which in combination remarkably reduce the material used, which is subsequently left inside the patient.

Description:
[0001]    The present invention refers to a prosthesis to be used for surgical therapy of female urinary incontinence and urogenital prolapse. 
       BACKGROUND OF THE INVENTION 
       [0002]    By urinary incontinence it is meant, in general, involuntary loss of urine through the urethra, which evidently causes hygienic, economic and social problems. The subject-matter of the present invention concerns the treatment of stress urinary incontinence (SUI), consisting in the loss of urine consequent to increases of the abdominal pressure caused by coughs, sneezes, lifting of weights, etc.; a condition this occurring when bladder pressure exceeds urethra pressure, in the absence of normal compensation mechanisms. 
         [0003]    Stress urinary incontinence may be related to alterations of pelvic floor muscles, or to an intrinsic urinary deficit. Factors that can cause said pathology are advanced age, delivery, pregnancy, menopause, smoking and obesity. 
         [0004]    Three degrees of SUI may be distinguished, and precisely:
       first degree: losses of urine when coughing, laughing or sneezing;   second degree: losses of urine when lifting weights or climbing stairs;   third degree: losses of urine when standing, but not when lying down.       
 
         [0008]    Urogenital prolapse is a pathology characterized by the inferior displacement of the vagina and uterus, accompanied by dislocation of the adjacent pelvic viscera, due to a sagging of their supporting means. Urogenital prolapse can be caused by delivery-provoked relaxation, menopause, but also by a chronic constipation. 
         [0009]    Prolapse may concern all organs in the pelvic cavity: the uterus, the vagina, the bladder and the rectum. These organs are held inside the pelvis thanks to the support by the pelvic floor muscles and to a suspension system formed by connective tissue. As years go by, muscles become less tonic and the connective layer grows thin, causing the sagging. It may also happen that the expulsive phase of delivery weakens these structures and, always with age advancing, relaxation gets to cause the prolapse. Moreover, the continual insult to muscles caused by a chronic constipation ends up by decreasing muscle tonicity. 
         [0010]    Urogenital prolapse entails a general worsening of the quality of life, causing various disturbances among which back pain, feeling of weight in the lower abdomen and local circulatory disturbances. The prevalence of urogenital prolapse is relevant among 15% to 35% of women, mostly in their fifties and sixties. The main clinical manifestation is an uncomfortable and bothersome feeling of protrusion or weight, localized at the level of the pelvis or of the perineum, and especially at the level of the vagina. These symptoms are worsened by the standing position, above all when prolonged. 
         [0011]    SUI phenomenon may be caused by urogenital prolapse, it being generated by a descent of the anterior wall of the vagina, the urethra and the bladder neck. Hence, often to urogenital prolapse also SUI is associated. 
         [0012]    In literature, several surgical methodologies are known for the treatment of urogenital prolapse and stress urinary incontinence. Aim of the surgical operation is to improve woman&#39;s quality of life, therefore it is envisaged only in case said quality is limited just by said pathologies. 
         [0013]    A surgical approach used for the correction of the urogenital prolapse is colpohysterectomy (removal of the uterus through the vagina), associated to anterior colporrhaphy. Anterior colporrhaphy, commonly known as “vagina plastic surgery” envisages the removal of redundant vaginal wall. 
         [0014]    In case of SUI associated to urogenital prolapse, beside the anterior colporrhaphy, SUI correction is performed by urethropexy. Such a technique entails the attachment of the urethra, at the ventral abdominal wall thereof, to the cranial end of the pubis, causing relocation of the bladder neck to an intrabdominal position and localized increase of urethral strength. However, it does not offer a high percentage of success, as at +6 months ˜1 year after operation recurrence phenomena have been observed in about the 30% of subjects subjected to said surgical treatment. Defects of discussed techniques are to be sought in the fact that in aged persons (like those subjected to this kind of operations) the collagen tissue formed following the operation is of a weak type, itself constituting a predisposition for a subsequent prolapse of the surgically treated structures. 
         [0015]    More recently, in urogynaecologic practice an innovative surgical technique has been introduced referred to as TVT (Tension-free Vaginal Tape). It is a technique utilizing a prosthesis formed by a mesh (commonly denominated “sling”) of non-reabsorbable or partially reabsorbable polyprOpylene applied, by “Tension Free” technique in a mini-invasive manner, on a position beneath the urethra, for supporting the same. The Tension Free technique is such that the inserted prosthesis does not exert direct traction on surrounding tissues, exploiting instead fibrosis phenomena developing shortly after implantation and tending to incorporate and hold in situ the prosthesis itself. TVT may be used to solve both the SUI problem and the urogenital prolapse problem. 
         [0016]    International Application WO 2004/098461 describes a prosthesis to be used in the surgical therapy of urogenital prolapse and urinary incontinence according to said TVT technique Such a prosthesis is constituted by a central body, made of non-reabsorbable or partially reabsorbable polypropylene mesh, comprising a first portion to be placed beneath the bladder neck and middle urethra and a second portion to be applied in correspondence of the body and base of the bladder. From said central body, two pairs of arms (always made of polypropylene mesh) extend to create, with “Tension Free” technique, an elastic support for supporting (preventing their future descent) the pelvic structures subjected to prolapse and incontinence. For prosthesis insertion, the surgical operation envisages the execution of incisions at the pelvic level for the insertion/extraction of curved needles for maneuvering, attached just to said arms. 
         [0017]    A further commercial product (“Gynecare TVT Secur ®”), made to treat exclusively SUI, is constituted by a prosthesis made of a non-reabsorbable or partially reabsorbable polypropylene mesh, yet devoid of arms, unlike the prosthesis described in International Pat. Appl. WO 2004/098461. In fact, in this case the supporting of the pelvic structures is carried out by the body of the sling itself, however having a length of about 8 cm, and therefore remarkably reduced with respect to similar prostheses present in literature. The operation for the insertion of such a product requires no execution of incisions, it being directly inserted via the vagina. 
         [0018]    Drawbacks of the Prior Art 
         [0019]    Referring to the prosthesis described in International Pat. Appl. WO 2004/09846, and generally to all prosthesis types similar thereto known in literature, the main drawback of the known art resides in the fact that the material left inside the body is clearly more than what is actually needed. In fact, the extension of the polypropylene mesh used (prosthesis body+arms) may be cause of complications that can be found during the surgical operation itself or subsequently, like, e.g., infections, erosions and rejection. 
         [0020]    On the other hand, the Gynecare® product, by being constituted only of a sling, though of reduced dimensions, entails the advantage of drastically reducing the material inserted into the body, along with the fact of being inserted with no need to execute surgical incisions on the patient. Its remarkable drawback lies however in its limited supporting capability, associated just to the limited dimensions of the body and to its reduced “maneuvering” option—i.e., of adjusting the prosthesis position and tensioning level—during the insertion, related to the absence of arms. In fact, referring to the three degrees of seriousness of urinary incontinence, said prosthesis is capable of curing said pathology until the second level of seriousness only. 
       SUMMARY OF THE INVENTION 
       [0021]    Hence, the technical problem set and solved by the present invention is to overcome the drawbacks hereto-mentioned with reference to the known art. 
         [0022]    Such a problem is solved by a prosthesis according to claim  1 . 
         [0023]    Preferred features of the invention are provided in the dependent claims hereinafter. 
         [0024]    The prosthesis subject-matter of the present invention proposes the union of a main prosthetic body—typically made of a synthetic or biologic non-reabsorbable or partially reabsorbable mesh—with special and preferably self-locking thread-shaped members for the in situ positioning, with the desired tension level, of the prosthesis. Such thread-shaped members are adopted in lieu of the arms of considerable extension provided in some known prostheses, and are them also partially or totally absorbable or not absorbable. 
         [0025]    The adoption of such thread-shaped members allows to remarkably reduce the material used, which is subsequently left inside the patient. Thus, it is prevented any short- and long-term complication hereto-mentioned with reference to the known art, though attaining a surgical aid suitable for the treatment of stress urinary incontinences of any level, as well as of urogenital prolapse. 
         [0026]    Moreover, the thread-shaped structure of the members intended for positioning and, at least initially, in situ holding of the prosthesis, allows a greater simplicity of surgical operation, a reduction of operating times and therefore of anesthesia times and amounts and a limited need of dissection with respect to what to date is envisaged in the art in order to implant the known prostheses. 
         [0027]    Therefore, the prosthesis subject-matter of the present invention is truly mini-invasive. 
     
    
     
       BRIEF DESCRIPTION OF THE FIGURES 
         [0028]    Other advantages, features and the operation modes of the present invention will be made apparent from the following detailed description of some embodiments thereof, given by way of example and not for limitative purposes. Reference will be made to the figures of the annexed drawings, wherein: 
           [0029]      FIG. 1  shows a top perspective view of a prosthesis according to a first preferred embodiment of the present invention; 
           [0030]      FIGS. 2 and 3  show each a perspective enlarged view of the prosthesis of  FIG. 1 , depicting an embodiment detail thereof; 
           [0031]      FIG. 4  schematically shows the last phase of the surgical technique for implantation of the prosthesis of  FIG. 1 ; 
           [0032]      FIG. 5  shows a top perspective view of a prosthesis according to a second preferred embodiment of the present invention; and 
           [0033]      FIG. 6  schematically shows the last phase of the surgical technique for the application of the prosthesis of  FIG. 5 . 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0034]    Referring initially to  FIG. 1 , a first embodiment of a prosthesis according to the invention is generally denoted by  1 . 
         [0035]    The prosthesis  1  comprises a main central body  2  realizing the support for the urethra; at the two opposite ends of the body  2  there are linked, in a manner that will be described hereinafter, two self-locking thread-shaped members  3 ,  3 ′, by which said central body  2  is positioned to support the urethra. 
         [0036]    The body  2  is made of a biocompatible material and is apt to be placed in a position substantially underlying at least the middle urethra. 
         [0037]    In particular, in the embodiment considered herein, the main body  2  is designed for the treatment of first-, second- or third-degree stress urinary incontinence (SUI), depending on the specific extension of the body  2  itself. Just depending on such an extension, the body  2  could be placed even under the bladder body and base, beside under the middle urethra. 
         [0038]    The central body  2  may be made of a non-reabsorbable (e.g. polypropylene) or partially reabsorbable (e.g., polypropylene and glycolide) material, or of a biologic material (e.g., pericardium). 
         [0039]    In the embodiment depicted here, the central body  2  has a mesh-like structure  9  of non-reabsorbable polypropylene (C 3 H 6 ) n  monofilaments, and having a substantially oblong shape. In correspondence of opposite longitudinal ends  4 ,  4 ′ thereof, the central body  2  has two extensions  5 ,  5 ′. Each of said extensions  5 ,  5 ′ comprises a first gradual narrowing, respectively denoted by number references  14 ,  14 ′, ending with an appendage  15 ,  15 ′, respectively, having substantially tapered contour. 
         [0040]    Substantially in correspondence of a terminal end  6 ,  6 ′ of each appendage  15 ,  15 ′, a linking is made between a respective thread-shaped member  3 ,  3 ′ and the body  2 . By said linking, the thread-shaped members  3 ,  3 ′ are attached to the body  2  itself and can therefore exert traction thereon, thereby allowing a correct positioning and tensioning of the prosthesis  1  and thus implementing means for positioning the latter. 
         [0041]    The modes of connecting each thread-shaped member  3 ,  3 ′ to the main body  2  are depicted in greater detail in  FIG. 2 . 
         [0042]    Referring to the latter figure, at the making of the prosthesis  1  a first terminal end  8  of a thread-shaped element, in the present example the member denoted by  3 , is inserted through a weave of the mesh  9  of the respective appendage  15 , and subsequently attached to a second terminal end  10  of the thread-shaped member  3  itself. Thus, the linking between body  2  and thread-shaped member  3  occurs substantially at the middle point of the latter. Likewise, the thread-shaped member  3 ′ is linked substantially in correspondence of an end  6 ′ of the respective appendage  15 ′. In this case as well, a first end  8 ′ of the thread-shaped member  3 ′, upon crossing the weave of the mesh  9 , is attached to a second end  10 ′. 
         [0043]    Therefore, in the present example the connection between each thread-shaped member  3 ,  3 ′ and main body  2  is made so that the element  3 ,  3 ′ itself describes a loop or a ring and is connected to the body  2  in correspondence of a race or arc of said loop or ring, so that each member  3 ,  3 ′ defines a twin member for tensioning the main body  2 . 
         [0044]    It will be appreciated that the linking between thread-shaped members  3 ,  3 ′ and central body  2  by interposition of the tapered extensions  5 ,  5 ′ allows even distribution of the stresses generating during the traction of the body  2  itself. Linking the body  2  directly at its central portion would generate therein a state of three-axial tension that could cause the forming of folds, the onset of unevenly stressed zones or anyhow the kinking of the former. 
         [0045]    Each thread-shaped member  3 ,  3 ′ has, along its own axial development, a plurality of ears (of wheat)  7 , whose tilt is such as not to generate contrast with neighboring tissues and organs during the positioning of the prosthesis, and such as not to allow over time a relaxation thereof that would cause its loss of efficiency. In particular, at the two tensioning sections of each of the above-defined member  3 ,  3 ′ said ears  7  have substantially opposite tilts, just to ensure a proper grip on the tissues. 
         [0046]    As it is shown in greater detail in  FIG. 3 , the joined ends  8 - 10  and  8 ′- 10 ′ of each thread-shaped member  3 ,  3 ′ may be assembled inside a means for insertion in the patient&#39;s body, and particularly in correspondence of a respective curved needle  12 ,  12 ′, having for this purpose a mouth  13 ,  13 ′, and be secured thereto by pressing of said mouth  13 ,  13 ′. 
         [0047]    According to a variant embodiment, the two joined ends  8 - 10  and  8 ′- 10 ′ of the elements  3 ,  3 ′ may be left free. In this latter case, the insertion into the patient&#39;s body and the dragging of the members  3 , 3 ′ during the operation may be carried out by use of external instruments (like, e.g., needles). 
         [0048]    The thread-shaped members  3 ,  3 ′ may be made of a non-absorbable (e.g., polypropylene), partially absorbable (e.g., polypropylene and glycolide) or absorbable (e.g., polydioxanone) material. 
         [0049]    According to a preferred execution, the operation of implantation of such a prosthesis  1 , in this case designed for therapy of first- second- or third degree urinary incontinence, occurs by vaginoperineal approach with the catheterized patient in a lithotomic position pushed into Trendelenburg position. Anesthesia may be preferably local, local-regional or general. 
         [0050]    Always according to a preferred embodiment, a median longitudinal incision of about 1 cm is made in the anterior wall of the vagina, at about 1 cm from the urethral tubercle. Vaginal mucosa, vaginal muscular mucosa and fascia are incised, a paraurethral beveled dissection is made up to the middle margin of the ischiopubic ramus (1 cm lateral to the urethra with a 45-degree direction with respect to the ischiopubic ramus). Needle  12  of the prosthesis  1  is mounted on a needle holder and passed through the tunnel prepared beforehand, and then through the pubocervical fascia, the musculus obturator internus, to the obturator fascia, transiting close to the posterior margin of the ischiopubic ramus, to make it emerge at the inguinal skin, through the obturator foramen at the inferomedial margin thereof. The point of emergence of the needle  12  corresponds to the intersection of two straight lines, one going through the base of the clitoris and one through the inguinal folds. 
         [0051]    The operation is repeated on the other side. Traction is applied to the thread-shaped members  3 ,  3 ′, and the central part of the prosthesis  1  is positioned under the middle urethra. 
         [0052]    The self-locking thread-shaped members  3 ,  3 ′ allow to adjust and support the prosthesis  1  until fibrosis is attained, to then reabsorb gradually, with the result of a remarkable reduction of implanted material. Continence is tested by stress test (e.g., coughs with 250 ml in bladder) with the main body  2  “loose” and then in position. A “Tension-Free” check is performed (about 3-4 mm between main body  2  and urethra). Vaginal breach is sutured with reabsorbable material. Then, the members  3 ,  3 ′ are cut at skin emergence and the operation is concluded with suitable medications. 
         [0053]      FIG. 4  shows just the last phase of the surgery for in situ implantation of the prosthesis  1 . In particular, there are highlighted two incisions  16 ,  16 ′ from which the self-locking threads  3 ,  3 ′ emerge. As mentioned above, subsequently to having tensioned said central body  2  (not visible) to support the middle urethra by applying traction to the threads themselves, they are cut at the skin emergence spot. 
         [0054]    There will now be briefly described a second embodiment of the prosthesis of the invention, which can advantageously be used to solve with a single surgery the problems of urinary incontinence and of urogenital prolapse. This further embodiment will be described only referring to the elements differentiating it from the first embodiment already disclosed. 
         [0055]    Referring to  FIGS. 5 and 6 , a prosthesis  1 ′ comprises a central body  32  to which there are linked, in the aforedescribed manner, four self-locking thread-shaped members  33 ,  33 ′,  63  and  63 ′, by which the central body  32  is positioned to support the urethra and the body and base of the bladder. 
         [0056]    The main body  32  has a substantially quadrilateral shape, and said thread-shaped members  33 ,  33 ′,  63  and  63 ′ originate therefrom substantially in correspondence of the vertexes of a quadrilateral. 
         [0057]    Otherwise, the main body  32  and the members  33 ,  33 ′,  63  and  63 ′ may have a realization in all analogous to that described hereto with reference to the first embodiment. 
         [0058]    It will be appreciated that in the present case the presence of four thread-shaped members, rather than two, for making the positioning means serves to ensure a correct in situ positioning of the prosthesis and a correct tensioning and support thereof. 
         [0059]    Analogously to what has been described hereto, the thread-shaped members  33 ,  33 ′,  63 ,  63 ′ comprise along their axial development a plurality of ears (for simplicity&#39;s sake not depicted) similar to those disclosed hereto. 
         [0060]    Always analogously to what has been described hereto, substantially in correspondence of its own opposite ends  34 ,  34 ′, and  64 ,  64 ′ defining the vertexes of a quadrilateral, the central body  32  has respective extensions  35 ,  35 ′ and  65 ,  65 ′ analogous to those already disclosed. 
         [0061]    It will be appreciated that according to a variant embodiment—compatible both with the first and the second embodiment disclosed hereto—the thread-shaped members of the prosthesis may originate directly from the main portion of the central body, instead of providing suitable tapered extensions of the latter. 
         [0062]    In  FIG. 6  it is schematically depicted the last phase of the surgical operation for the positioning of said prosthesis  1 ′. In particular, there are highlighted four incisions  86 ,  86 ′ and  96 ,  96 ′ from which the self-locking members, respectively  33 ,  33 ′ and  63 ,  63 ′, emerge. Subsequently to having tensioned said central body  32  (not visible) by applying traction to the threads themselves, they are cut at the skin emergence spot. 
         [0063]    The present invention has hereto been described with reference to two preferred embodiments thereof. It is understood that other embodiments might exist, all falling within the same inventive kernel, and all comprised within the protective scope of the claims hereinafter.