Endo-urethral prosthesis including an abdominal pressure-actuated stopper portion

Abstract

An endo-urethral prosthesis (1a-n) comprises a proximal part (2) and a distal portion (4), comprising respective proximal and distal tubular portions (24,46) configured to be arranged within a patient's urethra (7), and respective proximal and distal stents (21,49) configured to anchor within a urethra-vesical lumen and to a urethra, respectively, the proximal and distal tubular portions (24,46) having predetermined radial rigidity and forming a longitudinal duct (5) arranged to convey urine. Endo-urethral prosthesis 1 further comprises at least one valve body (150) configured to elastically deform, when an opening differential pressure (P*) is exceeded, from a closed configuration to an open configuration, so that it can be opened by an increase in abdominal pressure. A plug element (156) of the valve body (150) comprises resilient walls (155) separated by through slits (157) converging from a peripheral portion of the plug element to a convergence point (159). According to one aspect of the invention, the resilient walls (155) there is at least one differently flexurally rigid resilient wall (155a) which has a different bending stiffness than the other resilient walls (155). According to another aspect of the invention, the valve body further includes a tubular intermediate part (3) interposed in a detachable manner between the proximal part (2) and the distal part (4), and the valve body is arranged within said tubular intermediate part (3).

Description

ENDO-URETHRAL PROSTHESIS INCLUDING AN ABDOMINALPRESSURE-ACTUATED STOPPER PORTIONDESCRIPTION of the invention

[0001] The present invention relates to an endo-urethral device for treating stenosis of the male urethral duct due to prostatic hypertrophy and / or for treating urinary incontinence conditions in male and female subjects.Prior art - Technical problems

[0002] As is known, in some instances, prostatic hypertrophy causes stenosis of a longer or shorter portion of the urethra near the bladder, making it difficult to empty the bladder. It is also known that the micturition involves a first sphincter that is known as the internal urethral sphincter, placed immediately outside the bladder outlet, and a second sphincter known as the external urethral sphincter, placed further downstream, with the prostate surrounding a portion of the urethra between the two sphincters, in the case of male subjects. The external urethral sphincter is made up of striated muscle and its control is voluntary, so as to prevent / allow urination. In general, subjects suffering from prostatic hypertrophy retain the function of the external sphincter and do not suffer from urinary incontinence as a result.

[0003] Urinary incontinence conditions are also known to occur in both male and female subjects who are unable to control the external urethral sphincter adequately or at all. Various artificial sphincters exist to treat these conditions, used when remedies such as outpatient therapy, drug therapy and pelvic reeducation are not effective. Some artificial sphincters are enclosed by a tubular casing of assigned length for insertion into the urethra, within which one or more valve bodies of various types are arranged. Devices of this type are described, for example, in WO2013144770.

[0004] Endo-urethral devices are known comprising valve bodies in which a diaphragm stopper is arranged transversely to such a tubular casing and is formed by resilient walls arranged radially and separated from each other bythrough slits converging towards the centre of the device. Such resilient walls are configured to switch from a rest closed configuration to a forced open configuration when the urine pressure acting thereon exceeds a predetermined opening pressure, and are further configured to resiliently return to the closed configuration once the urine pressure has been released.

[0005] Such valve bodies are described, for example, in the above- mentioned international patent application WO2013144770 and are particularly cheap and easy to manufacture. However, in these valve bodies, the opening and, in particular, the closing of the stoppers may not be complete. More specifically, an imperfect opening of the stopper can lead to the formation of an open lumen that is too small, which makes it rapid difficult to quickly evacuate the urine. On the other hand, an imperfect reclosure can cause an inadequate seal of the valve body. In some instances, when the resilient walls come together upon reclosing, they interlock mutually. This can cause unintentional leakage of the urine, which occurs through a residual opening that remains at the end portions of the resilient walls.

[0006] To mitigate this issue, devices comprising two of such valve bodies arranged in series have been proposed. In addition, or as an alternative, for the same purpose, other devices include a sliding safety plunger that is magnetically operated from outside the patient's body and that has a head portion shaped in such a way to keep the resilient walls of the valve body or such valve body or of one of such valve bodies in the closed configuration, when the head portion of the plunger is located adjacent to the valve body. In this regard, see some of the embodiments of WO2013144770. However, these anti-leakage measures complicate the construction and operation of the devices, and increase their production costs.

[0007] Endo-urethral prostheses that can be operated by intra-abdominal pressure augmentation, such as those of the prior art mentioned above, also present the problem of requiring that the opening pressure and the reclosing pressure are predetermined as precisely as possible, in order to predict the behaviour of a prosthesis as accurately as possible, once the prosthesis has been implanted in a patient’s body. In fact, the intra-abdominal pressures that the patients can exert in addition to urine pressure may vary considerably from one patient to another.Disclosure of the invention

[0008] It is therefore an object of the present invention to provide an endo- urethral device comprising a duct for the passage of urine and a stopper arranged within said duct and formed of resilient walls arranged radially and separated from each other by through slits converging at the centre of the stopper, which is substantially free from imperfect opening and re-closing issues and, in particular, free from leakage problems.

[0009] It is also an object of the invention to provide a method and a device for testing whether the actual sealing and opening pressure values of a specific valve body, or of each valve body of a production batch correspond to their respective design values, the device configured to switch from a rest closed configuration to a forced open configuration when the urine pressure acting thereon exceeds the opening value, and configured to resiliently return to the closed configuration once that pressure has fallen below a reclosing value, due to the urine release.

[0010] It is a particular purpose of the invention to perform such a test of opening and reclosing pressures in the case of a valve body including a plug comprising a diaphragm in which resilient walls are separated from each other by through slits, as in the prior art mentioned above.

[0011] These and other purposes are achieved by an endo-urethral prosthesis as defined in claims 1 and 12, as well as by a method for testing the opening pressure and reclosing pressure of a stopper portion as defined in claim 13. Advantageous embodiments of the endo-urethral prosthesis are defined in the dependent claims.

[0012] Such an endo-urethral prosthesis comprises a proximal part and a distal part, wherein the proximal part comprises: a proximal tubular portion configured to be arranged within a patient's urethra, and a proximal stent configured to be reversibly fixed to an inner wall of a urethra-vesical lumen; wherein the distal part comprises: a distal tubular portion configured to be arranged within the urethra, anda distal stent configured to be reversibly fixed to the inner wall of the urethra, wherein: the proximal tubular portion and the distal tubular portion define a rigid longitudinal duct arranged to convey urine; a valve body is fluid-tightly arranged within the longitudinal duct and includes a stopper portion comprising resilient walls separated from each other by a plurality of through slits converging at a convergence point, and wherein the stopper portion is configured for: resisting a differential pressure acting on a face of the stopper portion facing the proximal stent and maintaining a closed configuration in which the resilient walls are contiguous to each other along the through slits, as long as the differential pressure does not exceed a predetermined opening pressure of the valve body, and for collapsing from the closed configuration, in which urine cannot pass through the longitudinal duct, to an open configuration, in which the resilient wall are deformed and spaced apart, so that urine can pass through the longitudinal duct when the differential pressure becomes higher than the opening pressure,- returning from the open configuration to the closed configuration when the differential pressure becomes again lower than the opening pressure, in such a way that the patient, by causing an own abdominal pressure to increase, can cause the differential pressure to exceed the opening pressure and thus cause the configuration of the stopper portion to turn from the closed configuration to the open configuration.

[0013] According to one aspect of the invention, the valve body is arranged within at least one portion between the proximal tubular portion and the distal tubular portion, and the resilient walls comprise at least one differently flexurally rigid resilient wall that has a flexural rigidity different from the flexural rigidity of the other resilient walls.

[0014] Thus, regardless the resilient walls have the same surface area or not, they deform differently with respect to each other under the action of respective different opening forces. In particular, the resilient wall(s) that is / are differently flexurally rigid deform more or less than the others, depending onwhether they have a lower or higher stiffness than the other resilient walls. This differential deformation behaviour drastically decreases the probability that, upon reclosing the stopper portion, the resilient walls will interlock with each other. In such a case, upon reclosing the stopper portion, an opening could remain between the walls, which would connect the portions of the longitudinal duct upstream and downstream of the stopper portion to each other, and an urine leakage could take place even when the device is supposed to be closed.

[0015] As is well known, the bending stiffness of a component such as the resilient walls of the valve body depends on the elastic modulus and on the value of the central moment of inertia, which, in general, varies from one section of the resilient wall to another. It is possible to design the valve body in such a way that one or more of the resilient walls have / have a different bending stiffness, compared to the other resilient walls, by changing their elastic modulus, for example a) by using a material with a different elastic modulus for the wall(s) that is / are desired to be differently flexurally rigid, or b) by incorporating a filler or reinforcing material into the wall(s) that is / are desired to be differently flexurally rigid. It is also possible to change the flexural stiffness by modifying the geometric characteristics that affect the central moment of inertia of some of the resilient wall sections. This can be achieved, for instance, by modifying the thickness or the curvature of a resilient wall locally or all over its extension. Some of these possibilities, which are not limiting, are described below, with reference to embodiments and respective modifications of the invention.

[0016] According to another aspect of the invention, the endo-urethral prosthesis further comprises an intermediate tubular part interposed in a detachable manner between the proximal part and the distal part, and the valve body is arranged within the intermediate tubular part.

[0017] By placing the valve body in the tubular intermediate portion, the formation of a minimal urine head is ensured over the stopper portion, even after the latter has been closed, which exerts a residual pressure on the stopper portion. This allows a more accurate control of the opening and especially the correct re-closing of the stopper portion, so that no residual openings are left and urine leakage is prevented when the endo-urethral prosthesis is nominally closed.

[0018] In particular, the differently flexurally rigid resilient wall of the of the valve body of the endo-urethral prosthesis is made of a material that has a higher or lower elastic modulus than the other resilient walls.

[0019] As an alternative, in some embodiments, the differently flexurally rigid resilient wall and the other resilient walls can be made entirely of materials with the same modulus of elasticity, for instance, in a same material.

[0020] In particular, in some of those embodiments, the differently flexurally rigid resilient wall has at least one section whose thickness is greater or lower than corresponding sections of the other resilient walls. In particular, in some modifications of these embodiments, the differently flexurally rigid resilient wall has at least one protuberant portion and / or a recessed portion that protrudes or is recessed with respect to its own surface. As an alternative, in some different modifications of these embodiments, the differently flexurally rigid resilient wall has the greater or lower thickness all over its own extension.

[0021] In some different embodiments among those in which the differently flexurally rigid resilient wall and the other resilient walls are entirely made of materials having a same modulus of elasticity, the differently flexurally rigid resilient wall has at least one section with a curvature different from the curvature of corresponding sections of the other resilient walls.

[0022] In particular, the section with a different curvature comprises at least two contiguous portions that have different curvatures with respect to each other and that are separated by an edge portion.

[0023] As an alternative to the above, the differently flexurally rigid resilient wall and the other resilient walls comprise respective matrices made of first materials having a same elastic modulus, in particular made of a same first material, and in one matrix, among said matrices, of the differently flexurally rigid resilient wall, a body or a plurality of bodies is embedded made of a second material having an elastic modulus different from the elastic modulus of the first material or materials.

[0024] ] In this case, in one embodiment, the embedded body in the matrix of the differently flexurally rigid resilient wall can be in the form of a foil, not necessarily a metallic foil, preferably but not limitatively arranged radially. In another embodiment, the embedded body can be a fabric formed from fibres ora material similar to a fabric such as a non-woven fabric. ]ln yet another embodiment, the plurality of bodies comprises a granular material randomly arranged as a filler within the matrix of the differently flexu rally rigid resilient wall. In a still further embodiment, the plurality of bodies may comprise a fibrous material with the fibres arranged randomly or in an orderly manner, in particular parallel to each other, within the matrix of the differently flexurally rigid resilient wall.

[0025] Preferably, in the various embodiments mentioned above, the resilient walls are symmetrically arranged with respect to a central longitudinal axis of the valve body. Preferably, the total number of resilient walls is between 3 and 8, more preferably four resilient walls are provided.

[0026] Preferably, the proximal tubular portion and / or the distal tubular portion have a diameter set between 3 and 10 mm, and a wall thickness set between 0.2 and 0.8 mm.

[0027] According to a further aspect of the invention, there is provided a method for verifying the design sealing pressure and the design opening pressure of a valve workpiece of an endo-urethral device, wherein a stopper portion comprises a plurality of resilient walls separated from each other by a plurality of through slits. The method comprises the steps of: prearranging a source of a test gas at a predetermined source pressure; mounting the valve workpiece in a mounting site of a test container having an inlet port and an outlet port for the test gas, wherein is performed in such a way to form a gas-tight seal between the inlet port and the outlet port; introducing the test gas into the test container at a predetermined test pressure increasing over time from a minimum value below the design sealing pressure up to the design sealing pressure; waiting until a predetermined detection time (tn) has elapsed; detecting an upstream pressure upstream of the valve workpiece; comparing the upstream pressure with the design sealing pressure; if the comparison indicates that the upstream pressure has become significantly lower than the design sealing pressure, rejecting the valve workpiece;if, instead, after the maximum detection time, the comparison indicates that the upstream pressure remains substantially the same as the design sealing pressure, validating the design sealing pressure; increasing the test pressure and, simultaneously, awaiting / detecting a presence of an outlet flow of said test gas through outlet port of the test container; if the outlet flow is not detected before the upstream pressure reaches the design opening pressure, rejecting the valve workpiece; if, on the other hand, the outlet flow is detected before the upstream pressure reaches the design opening pressure, validating the design opening pressure, and accepting the valve workpiece.Brief description of the drawings

[0028] The invention is illustrated below by a description of certain embodiments, by way of example and not limitation, with reference to the accompanying drawings, in whichFigs. 1 and 2 schematically show an endo-urethral prosthesis placed in the urethra of a female and male patient suffering from urinary incontinence, respectively;Fig. 3 schematically shows a condition of urethral stenosis in a male patient suffering from prostatic hypertrophy;Fig. 4 shows schematically an endo-urethral prosthesis placed in the urethra of the patient of Fig. 3 to resolve urethral stenosis;Fig. 5 is a schematic side view of an endo-urethral prosthetic device according to a first aspect of the invention;Figs. 6-8 schematically show, in a perspective view, a top view and a cross- sectional view, respectively, a valve body comprising a valve plug in which resilient walls are arranged radially and separated from each other by through slits converging towards the centre of the device, according to the above-mentioned prior art;Figs. 8-1 1 illustrate an opening and closing cycle of a valve body as in Figs. 6-8, highlighting, Fig. 1 1 , a possible reclosure defect;Figs. 12-14 schematically show, in a perspective view, a top view and a cross-sectional view, respectively, a valve body according to an embodiment of the invention based on an increased local thickness of the differently rigid resilient wall, obtained by a protuberance;Figs. 15-17 schematically show, in a perspective view, a top view and a cross-sectional view, respectively, a valve body according to an embodiment of the invention based on a reduced local thickness of the differently rigid resilient wall, obtained by a recess;Figs. 18-20 schematically show, in a perspective view, a top view and a cross-sectional view, respectively, a valve body according to an embodiment of the invention based on a uniformly increased thickness of the differently flexurally rigid resilient wall;Figs. 21 and 22 schematically show, in a perspective view and in a top view, respectively, a valve body according to an embodiment of the invention, in which the resilient walls have thicknesses uniformly different from each other;Figs. 23 and 24 are two schematic cross-sectional views of the valve body shown in Figs. 21 and 22;Figs. 25 and 26 are schematic cross-sectional views of valve bodies according to an embodiment of the invention based on a locally increased curvature of a section of a differently flexurally rigid wall;Fig. 27 is a schematic cross-sectional view of valve bodies according to an embodiment of the invention in which the differently flexurally rigid resilient wall comprises two contiguous portions that have different curvatures and that are separated by an edge portion;Figs. 28-31 schematically show, in respective cross-sectional views of valve bodies according to some embodiments of the invention in which bodies / pluralities of bodies of materials having different elastic modulus are embedded in the matrix of the differently flexurally rigid resilient wall, i.e.: a foil; a granular material; a plurality of loose fibres (166j) ; a fabric of fibres,respectively.Figs. 32a-32e are schematic perspective views of a prior art valve as in Figs. 6-8, showing how the shape of the stopper portion changes over time during an opening-reclosing cycle;Figs. 33a-33e are schematic perspective views of a valve according to the invention as illustrated in Figs. 12-31 , showing how the shape of the resilient walls changes over time during an opening-reclosing cycle;Fig. 35 is a schematic exploded perspective view of an endo-urethral prosthetic device according to a second aspect of the invention;Fig. 36 is another schematic exploded perspective view of the endo- urethral prosthetic device in Fig. 35, with the valve body mounted in the intermediate tubular part;Fig. 37 is a schematic perspective view of the endo-urethral prosthetic device of Figs. 35 and 36 once it has been assembled;Fig. 38 is a schematic cross-sectional perspective view of a valve body including a stopper portion formed by resilient walls that are arranged radially and are separated from each other by through slits converging towards the centre of the device, according to an embodiment of to the second aspect of the invention;Fig. 39 is a schematic exploded perspective view of a test container of an apparatus for verifying the design sealing pressure and the design opening pressure of a valve body for an endo-urethral prosthesis according to the invention; figure 40 is a schematic exploded perspective view of the test container of figure 39 once assembled with the valve body to be tested;Figs. 41 and 42 schematically show the apparatus for verifying the design sealing pressure and the design opening pressure in two separate steps of a method for verifying such design pressures;Figs. 43 and 44 are diagrams showing how change the pressures measured during the steps of Figs. 41 and 42;Fig. 45 shows a flow chart of the verification method for these design pressures.Description of preferred embodiments of the invention

[0029] With reference to Figs. 1 -34, there follows a description of some embodiments according to a first aspect of the invention, and modifications thereof, relating to an endo-urethral prosthesis for treating male and female patients suffering from urinary incontinence, as well as male patients with prostatic hypertrophy such that the urethra is stenosed at the prostate.

[0030] With reference to Fig. 5, an endo-urethral prosthesis 1 comprises a proximal part 2 and a distal part 4 including proximal and distal tubular portions 24,46, integral with each other and having a predetermined radial rigidity, proximal tubular portion 24 and distal tubular portion 46 preferably have a diameter of between 3 and 10 mm, and a wall thickness of between 0.2 and 0.8 mm.

[0031] As shown in Figs. 1 , 2 and 4, endo-urethral prosthesis 1 is configured to be disposed within urethra 7 of a female patient (Fig. 1 ) or a male patient suffering from urinary incontinence (Figs. 2 and 4), preferably at the connection between the bladder 6 and urethra 7. More specifically, proximal and distal tubular portions 24,46 are configured to be arranged within urethra 7, and fixation means (Fig. 5) such as a proximal stent 21 and a distal stent 49 are provided to stably but reversibly arrange endo-urethral prosthesis 1 in a predetermined position within urethra 7. Proximal and distal stents 21 and 49 are configured to be reversibly fixed to an inner wall of a urethra-vesical lumen 6-7 and of urethra 7, respectively.

[0032] In this description, the adjectives "proximal" and "distal" refer to the patient wearing endo-urethral prosthesis 1 .

[0033] Still with reference to Fig. 5, proximal and distal tubular portions 24,46 together form a longitudinal endo-urethral duct 5 that is rigid enough to maintain its own shape under implantation conditions, and that is suitable for conveying the urine 100 contained in bladder 6.

[0034] Proximal stent 21 and distal stent 49 are configured to elastically deform from an rest expanded configuration, shown in the figures, in which they have respective radial dimensions larger than the natural radial dimension of urethra 7, to a forced contracted configuration, in which the radial dimensions of proximal stent 21 and distal stent 49 are kept elastically constricted, so thatendo-urethral prosthesis 1 can be inserted and caused to slide within the lumen of urethra 7, until a predetermined implantation position of endo-urethral prosthesis 1 within urethra 7 is reached.

[0035] In the non-limiting embodiment shown in the figures, proximal stent 21 is configured to elastically anchor itself to an inner wall 6' of bladder 6, at the mouth of urethra 7 (Figs. 1 and 2), so as not to allow, after implantation, endo- urethral prosthesis 1 to move in a distal direction and thus prevent its expulsion from urethra 7.

[0036] More specifically, as shown in Fig. 5, proximal stent 21 may comprise a plurality of elongated anchor elements 22, each having a first end fixed to a circumferential position of a continuous proximal connecting ring 27a and a second end fixed to a respective flexible ring segment, the ring segments forming a connecting ring 27b to the body of endo-urethral prosthesis 1. Elongated anchor elements 22 are elastically flexible between a rest flexed conformation, shown in the figures, corresponding to the rest expanded configuration of proximal stent 21 , and an extended forced conformation, not shown, corresponding to the forced contracted configuration of proximal stent 21.

[0037] In this embodiment, distal stent 49 is configured to elastically anchor to an inner wall 7' of urethra 7 (Figs. 1 and 2), so as to prevent endo-urethral prosthesis 1 , after implantation, from moving in a proximal direction and ultimately entering bladder 6.

[0038] More specifically, in the embodiment shown in the figures, distal stent 49 can comprise a plurality of radial anchor elements 48 each radially protruding from a central element and elastically movable between a rest expanded position, shown in the figures, corresponding to the rest expanded configuration of distal stent 49, and a forced contracted position, not shown, corresponding to the forced contracted configuration of distal stent 49. The central element of distal stent 49 comprises a plurality of elongated flexible portions having one end attached to a respective flexible ring segment, the flexible ring segments forming a connecting ring 48a to the body of endo-urethral prosthesis 1 , for example, in the manner described further below.

[0039] More in detail, figure 1 refers to an implantation of endo-urethral prosthesis 1 in urethra 7 of a female patient, in which urethra 7 extends betweenthe bladder and the vulvar vestibule 7”, while figure 2 refers to an implantation of endo-urethral prosthesis 1 in urethra 7 of a male patient, wherein urethra 7 extends between the bladder and the glans 8' passing through patient’s penis 8.

[0040] Fig. 3 shows schematically a condition of stenosis of urethra 7 in a male patient due to hypertrophy of the prostate 9, and also shows, downstream of the region of urethra 7 affected by the stenosis, the striated muscle that controls the external urethral sphincter 9'. Fig. 4 shows schematically endo- urethral prosthesis 1 used to resolve the stenosis.

[0041] As still shown in Fig. 5, endo-urethral prosthesis 1 further comprises a valve body 150 fluid-tightly arranged within proximal tubular portion 24, as in this case, or distal tubular portion 46, in another case, not shown. As shown in Figs. 12 to 31 , valve body 150 comprises a stopper portion 156 formed by resilient walls 155, 155a,b,...,m which are separated from each other by a plurality of through slits 157 converging at a convergence point 159.

[0042] Resilient walls 155 and through slits 157 are made in such a way that stopper portion 156 is configured to resist a differential pressure AP acting on an upper face of stopper portion 156, i.e., on a face facing proximal stent 21 , and to maintain a closed configuration, in which resilient walls 155 are contiguous to each other along through slits 157, as long as differential pressure AP does not exceed a predetermined opening pressure P* of valve body 150. Stopper portion 156 is further configured to collapse from the closed configuration, shown in Figs. 8 and 9 for a prior art valve body 50 and in Figs. 12-31 for respective valve bodies according to some embodiments of the invention, in which urine 100 cannot pass through a longitudinal duct 5, to an open configuration, shown in Fig. 10 for prior art valve body 50, in which resilient walls 155 are deformed and spaced apart from each other, so that urine 100 can pass through longitudinal duct 5, allowing urination to a patient wearing endo- urethral prosthesis 1 , when differential pressure AP becomes higher than opening pressure P*. Moreover, resilient walls 155 are configured to return to the closed configuration when differential pressure AP again becomes lower than opening pressure P*.

[0043] In this way, the patient, by causing an increase in his / her own abdominal pressure, is able to increase differential pressure AP until the latterexceeds opening pressure P* and is thus able to switch stopper portion 156 from the closed configuration to the open configuration and perform urination.

[0044] The main feature of the present invention is that among resilient walls 155 there is at least one differently flexu rally rigid resilient wall 155a-f, i.e. a wall that has a different bending stiffness than the other resilient walls 155.

[0045] In the closed configuration, stopper portion 156 shown in the figures has a flat shape, but can alternatively have a convex shape, e.g. a dome shape, not shown, with a convexity facing the bladder side of urethra 7, i.e. oriented towards the bladder side, i.e. towards proximal stent 21 , such that a urine pressure acting on the upstream face of stopper portion 156 keeps through slits 157 closed, provided that the urine pressure does not exceed opening pressure P*. As anticipated, when opening pressure P* is reached, stopper portion 156 collapses due to elastic instability into an open configuration that is open towards distal stent 46, in which resilient walls 155are deformed and open, so stopper portion 156 is open as well, as shown in figure 10, so as to allow urine 100 to flow out through longitudinal duct 5 and, therefore, through urethra 7.

[0046] Resilient 155 walls can be obtained from a flat or convex thin membrane 153 by making through slits 157 through it, preferably by a punching operation.

[0047] Although the shown embodiments have four resilient walls 155, and four through slits 157, different numbers of resilient walls and through slits are possible.

[0048] Valve body 150 can comprise a peripheral cylindrical mounting portion 167 fluid-tightly mounted to an inner wall of longitudinal duct 5. Preferably, peripheral cylindrical mounting portion 167 has a circular cross- sectional area.

[0049] Stopper portion 156 preferably comprises a peripheral support disc 170 from which resilient walls 155 extend towards convergence point 159. Peripheral support disc 150 corresponds to a peripheral portion of membrane 153 which remains unchanged when through slits 157 are formed, e.g., punched. A connecting portion 168 of valve body 150 is also provided between peripheral support disc 170 and peripheral cylindrical mounting portion 167 described above.

[0050] In order to achieve a flexural rigidity of the differently flexurally rigid resilient wall(s) different from the flexural rigidity the other resilient walls 155, according to one embodiment, differently flexurally rigid resilient wall(s) may be made of a material with a different elastic modulus, i.e. significantly higher or significantly lower than the other resilient walls 155. In such an embodiment, the valve body can have a shape similar to that of prior art valve body 50 shown in Figs. 6-1 1.

[0051] On the other hand, Figs. 12-27 refer to valve bodies 150a-i according to some embodiments of the invention, including at least one differently flexurally rigid resilient wall 155a-i made of a material that has a same elastic modulus as the elastic modulus of the material of which the other resilient walls 155 are made. Preferably, differently flexurally rigid resilient wall 155a-i and the other resilient walls 155 are integrally made of materials having a same elastic modulus, in particular they are integrally made of a same material.

[0052] In a first embodiment of these embodiments, some modifications of which are shown in Figs. 12-24, differently flexurally rigid resilient wall 155a-f has at least one section 151 a-f whose thickness is higher or lower than the thickness of corresponding sections of the other resilient walls 155.

[0053] In a first modification of this embodiment, as shown in Figs. 12-14, differently flexurally rigid resilient wall 155a of valve body 150a has at least one protuberant portion 151 a protruding over its own upper surface, and over a plane defined by the upper surfaces of the other resilient walls 155.

[0054] In a second modification of this embodiment, shown in Figs. 15-17, differently flexurally rigid resilient wall 155b of valve body 150b has at least one recessed portion 151 b that is lowered with respect to its own upper surface, and with respect to a plane defined by the upper surfaces of the other resilient walls 155.

[0055] As an alternative, or in addition to the above protruding / recessed portions 151 a-b of differently flexurally rigid resilient wall 155a-b of valve bodies 150a-b, in further modifications, the differently flexurally rigid resilient wall(s) can have protuberant or recessed portions with respect to the lower surface of the differently flexurally rigid resilient wall(s).

[0056] In the present description, such adjectives as "upper" and "lower", when referring to the surfaces of the resilient walls, indicate surfaces facing proximal stent 21 and distal stent 49, respectively, of endo-urethral prosthesis 1.

[0057] As shown in Figs. 18-20, a third modification of this embodiment differs from the above first modification in that differently flexurally rigid resilient wall 155c of valve body 150c has a portion 151 c of increased thickness that extends to the whole upper surface of differently flexurally rigid resilient wall 155c, whereby differently flexurally rigid resilient wall 155c protrudes with respect to the plane defined by the upper surfaces of the other resilient walls 155.

[0058] Similarly, a fourth, not shown modification of this embodiment differs from the above second modification in that the differently flexurally rigid resilient wall has a portion of reduced thickness that extends to the whole upper surface of the differently flexurally rigid resilient wall, whereby the differently flexurally rigid resilient wall is completely recessed with respect to the plane defined by the upper surfaces of the other resilient walls 155.

[0059] In a fifth modification of this embodiment, shown in Figs. 21 -24, valve body 150d comprises a plurality of differently flexurally rigid resilient walls 155d- f and a correspondingly smaller number of other resilient walls, in comparison with valve body 150c of the third modification. In the case shown in Figs. 20-24, there is only one “other” resilient wall 155. More in detail, a first differently flexurally rigid resilient wall 155d has a thickness greater than the other resilient wall 155 (Fig. 23), a second differently flexurally rigid resilient wall 155e has a thickness greater than first differently flexurally rigid resilient wall 155d (compare the sectional views of Figs. 23 and 24) and a third differently flexurally rigid resilient wall 155f has a thickness greater than second resilient wall 155e (Fig. 24).

[0060] In a second embodiment, among the embodiments in which the material of differently flexurally rigid resilient wall 155g-i can have the same elastic modulus as the material of the other resilient walls 155, some modifications of which are shown in Figs. 25-27, differently flexurally rigid resilient wall 155g-i has at least one section 151 g-i that has a different curvature with respect to corresponding sections 151 of the other resilient walls 155.

[0061] In particular, Figs. 25 and 26 refer to a first modification and to a second modification of this embodiment, in which differently flexurally rigid resilient wall 155g and 155h of valve body 150g or 150h, respectively, exhibits a curvature different from the curvature of the other resilient walls 155 all over the extension of its own upper surface (Fig. 25) or of its own lower surface (Fig. 26). In corresponding other modifications, not shown, such different curvature may extend to a more limited portion.

[0062] In a third modification of this embodiment, as shown in Fig. 27, differently flexurally rigid resilient wall 155i of valve body 150i has its own zone 151 i that comprises two contiguous portions 152', 152" that have different curvatures and that are separated by an edge portion 154.

[0063] Figs. 28-31 refer to some modifications of a third embodiment of the invention, in which differently flexurally rigid resilient wall 155j-m of valve body 150j-m is made as a composite structure comprising a matrix, i.e., a continuous phase 165j-m and a filler, i.e. a dispersed phase 166j-m inclusing a body or a plurality of heterogeneous bodies that are substantially immiscible with the material of matrix 165j-m. Matrix 165j-m of differently flexurally rigid resilient wall 155j-m may be made of a first material having a same elastic modulus as the elastic modulus of the material of which the other resilient walls 155 are made, when these are not made as a composite structure.

[0064] In a first modification of this embodiment, as shown in Fig. 28, dispersed phase 166j embedded in matrix 165j of differently flexurally rigid resilient wall 155j comprises at least one sheet 166j that is preferably but not limitatively arranged radially with respect to a central longitudinal axis 54 of valve body 150j-m. Sheet 166j can be made of a metallic or non-metallic material.

[0065] In a second modification of this embodiment, as shown in Fig. 29, dispersed phase 166k embedded in matrix 165k of differently flexurally rigid resilient wall 155k comprises a randomly arranged granular material 166k as a filler within matrix 165k.

[0066] In a third modification of this embodiment, as shown in Fig. 30, dispersed phase 166£ embedded in matrix 165£ of differently flexurally rigid resilient wall 155£ comprises a plurality of loose fibres 166f, randomly or orderly arranged, for instance, along a same plane and / or parallel to each other in a radial direction with respect to central longitudinal axis 54 of valve body 150f.

[0067] In a fourth modification of this embodiment, shown in Fig. 31 , dispersed phase 166m embedded in matrix 165m of differently flexurally rigid resilient wall 155m comprises a plurality of fibres connected with one another to form a fabric 166m that is arranged, for instance, along a same plane in a radial direction with respect to central longitudinal axis 54 of valve body 150m.

[0068] In the figures, resilient walls 155 and 155a-m are symmetrically arranged with respect to central longitudinal axis 54 of valve body 150 and 150a- m. However, this feature is not limiting.

[0069] Figs. 32a-e and 33a-e show an opening-reclosing cycle of valve elements 50 and 150, according to the prior art and according to the invention, respectively. In other words, Figs. 32a-e and 33a-e show how resilient walls 55 and 155 of valve elements 50 and 150, change their position as urine pressure P changes, as shown in Fig. 34. Figs. 32a-e and 33a-e correspond to times ta- te, in the same order. At time ta, when bladder 6 is empty and urine pressure P is much lower than opening pressure P*, both valve elements 50 and 150 are in the closed configuration, i.e. resilient walls 55,155 are fully in contact with each other at respective through slits 57 and 157 (Figs. 32a, 33a). At time tb, when urine pressure P has almost reached opening pressure P*, corresponding to the maximum opening of the valve, prior art valve body 50 is still substantially closed, while valve body 150 already shows a small partial opening. This means a faster response capacity of valve body 150 according to the invention compared to prior art valve body 50. At time tc, when urine pressure P has reached opening pressure P*, valve body 150 is fully open, whereas prior art valve body 50 may exhibit a reduced passageway compared to valve body 150, and urine pressure P drops abruptly to zero, at times td and te, and resilient walls 55,155 are elastically drawn back to their respective closed configurations. However, as shown in Fig. 32e, resilient walls 55 of prior art valve body 50 may remain stuck together at the end of the opening-reclosing cycle, so that a residual passage may remain open in prior art valve body 50 even when no urine is present above it any longer to keep valve body 50 closed, so that leakage of urine is possible, whereas this never happens with valve body 150 of the invention, which is completely closed, see Fig. 33.

[0070] With reference Figs. 1 -4 and 35-37, an endo-urethral prosthetic device 1 n for treating patients with urinary incontinence is now described, according to a second aspect of the invention.

[0071] Endo-urethral prosthetic device 1 n comprises a proximal part 2 and a distal part 4 that include respective proximal 24 and distal 46 tubular portions configured to be arranged internally to a patient's urethra 7. Proximal and distal parts 2 and 4 include in turn proximal stents 21 and distal stents 49, respectively, which are configured to be reversibly fixed to inner wall 6' of bladder 6, at the mouth of urethra 7, and to inner wall 7' of urethra 7, respectively (Figs. 1 and 2). Stents 21 and 49 in the present embodiment can have the same shape as the corresponding stents of endo-urethral prosthesis 1 of the first embodiment.

[0072] An intermediate tubular part 3 is removably interposed between proximal part 2 and distal portion 4. Proximal tubular portion 24 and distal tubular portion 46 define together with intermediate tubular part 3 a rigid longitudinal duct 5 for conveying urine 100 contained in bladder 6.

[0073] Endo-urethral prosthesis 1 n further comprises a single valve body 250 which is fluid-tightly arranged within tubular intermediate portion 3. Also in this case, as shown in Fig. 38, valve body 250 comprises a stopper portion 256 formed by resilient walls 255 that are separated from each other by a plurality of through slits 257 that can converge at a convergence point 259 as shown not limitatively, but can also be arranged otherwise, for instance, at least in part parallel to each other or in any case at least in part not incident to each other.

[0074] Similarly to valve body 150a-m of the previously described embodiments according to the first aspect of the invention, resilient walls 255 and through slits 257 are manufactured in such a way that stopper portion 256 is configured to resist a differential pressure AP acting on an upper face of stopper portion 256, that is, on a face facing proximal stent 21 , and to maintain a closed configuration in which resilient walls 255 are contiguous to each other along through slits 257, as long as differential pressure AP does not exceed a predetermined opening pressure P* of valve body 250. Stopper portion 256 is also configured to collapse from a closed configuration, in which urine 100 cannot pass through longitudinal duct 5, to an open configuration, in which resilient walls 255 are deformed and spaced apart, so that urine 100 can pass through longitudinal duct 5, allowing urination to a patient wearing endo-urethralprosthesis 1 , when differential pressure AP becomes higher than opening pressure P*. Moreover, resilient walls 255 are configured to return to the rest closed configuration when differential pressure AP becomes lower than opening pressure P* again.

[0075] For instance, valve body 250 can have the features of valve body 50 of Figs. 6-1 1 , or even the features of one of the valve bodies 150a-m of Figs. 12-31 of the embodiments of the first aspect of the invention.

[0076] Fig. 35 also shows a possible way of connecting intermediate tubular portion 3 to proximal part 2 and to distal part 4, along with a possible way of mounting valve body 250 within intermediate tubular portion 3. More in detail, proximal tubular portion 24 and distal tubular portion 46 of proximal part 2 and distal part 4, respectively, have externally-threaded end regions 24' and 46'. Intermediate tubular portion 3 comprises a tubular element 80 and a pair of nuts 70' that are configured to be mounted on opposite ends 80a and 80b of tubular element 80. To this purpose, nuts 70’ comprise longitudinal protuberances 71 protruding radially along some outer generatrixes, in this case four outer generatrixes angularly spaced from one another by a same angle, in this case an angle of 90°. Tubular element 80 has longitudinal cuts 84 at own ends 80a- b, also in this case four longitudinal cuts 84 angularly spaced apart from one another by a same 90°angle. Longitudinal cuts 84 are arranged to receive each a respective longitudinal protuberance 71 of nuts 70’, so as to accommodate nuts 70’ at ends 80a-b and to lock the relative rotation of nuts 70’ with respect to tubular element 80. Moreover, nuts 70’ preferably have respective button protuberances 72 at outer generatrices distinct from those along which longitudinal radial protuberances 71 extend, while tubular element 80 has through holes 85 arranged to receive longitudinal radial protuberances 71 so as to also block relative axial mutual sliding, as well as rotation, between tubular element 80 and each of nuts 70’.

[0077] Nuts 70’ have a height H selected in such a way to form, when mounted on tubular element 80 along with valve body 250 interposed between them, a mounting seat for valve body 250 itself, said mounting seat short enough to axially tighten mounting portion 267 of valve body 250.

[0078] With reference to Figs. 41 -45, a method is now described for verifying whether a valve workpiece 350 for an endo-urethral prosthesis according to theinvention verifies the design values of the sealing pressure Psand of the opening pressure Po. In particular, valve workpiece 350 may comprise a stopper portion in which a plurality of resilient walls 355 are separated from each other by a plurality of through slits 357. More in particular, valve workpiece350 may be of the type shown in Fig. 38, i.e., resilient walls 355 and the through slits 357 of a stopper portion 356 can be convergent at a convergence point 359. Obviously, in order to carry out the method, valve body 350 can be any of the valve bodies described and depicted above.

[0079] Referring to the flowchart of Fig. 45, the method comprises a preliminary step S10 of prearranging a verification apparatus 89 as shown in Figs. 41 and 42, and subsequent steps S20 of verifying design sealing pressure Ps and / or S30 of verifying design opening pressure Po, the verification steps S20 and S30 preferably both carried out, and in the order as mentioned above.

[0080] Preliminary prearrangement step S10 comprises, in turn, a step S11 of prearranging a gas source S of a test gas G, for example compressed air, at a predetermined source pressure Pi; a step S12 of prearranging a pressure regulation device 96 for regulating a test pressure Pr of test gas G, typically a regulation valve 96, in such a way that pressure regulation device 96 receives test gas G from gas source S; a step S13 of prearranging a test container 90 provided with inlet and outlet openings 91 a and 91 c for test gas G and with a mounting seat 97 configured to accommodate valve workpiece 350 in such a way to fluid-tightly separate inlet port 91 a from outlet port 91 c, wherein inlet port 91 a is arranged to receive test gas G from pressure regulation device 96; a step S14 of prearranging a pressure-measuring device 94 arranged in such a way to measure pressure P of gas G upstream of valve workpiece 350 mounted in test container 90; and a step S15 of prearranging S15 a flow-blocking device 98 at outlet port 91 c, wherein the flow-blocking device 98 is configured to prevent / allow test gas G from flowing out of test container 90 through outlet port 91 c when pressure P is lower / greater than a predetermined flow block pressure, which in turn is lower than design sealing pressure Ps, and is provided with a means 98 for detecting and notifying such an outflow of test gas G.

[0081] In one embodiment, as shown in Figs. 39 and 40, test container 90 can comprise an upstream or gas-inlet portion 90a and a downstream or gasoutlet portion 90c configured to be mounted to each other, in this case, by alocking portion 90b. Gas inlet and outlet portions 90a and 90c include inlet and outlet openings 91 a and 91 c, respectively, preferably at the end portions of respective inlet and outlet ducts 92a and 92c. Gas outlet portion 90c also include a housing 93 for valve workpiece 350, said housing 93 defining mounting seat 97 inside. In this embodiment of test container 90, gas inlet and outlet portions 90a and 90c also include upstream and downstream sealing members 94a and 94c configured to receive valve workpiece 350 in a gas-tight montage arrangement, such that test gas G from inlet opening 91 a cannot escape from test container 90 but through valve workpiece 350 when the latter is in the open configuration, and then through outlet portion 90c. In this embodiment of test container 90, gas inlet and outlet portions 90a and 90c also include mutual locking members 93a-b, in particular, a male locking member 90a and a female locking member 90c, respectively, preferably having mutually compenetrating elements 95a and 95c such as a plurality of radial protrusions 95a of male locking member 93a and a corresponding plurality of radial recesses 95c of female locking member 93c each configured to receive a corresponding radial protrusion 95a of male locking member 93a by causing inlet portion 90a to slide against outlet portion 90c along a common longitudinal axis 99, wherein male and female locking members 93a and 93c are also configured to complete their mutual engagement by mutually rotating gas inlet and outlet portions 90 a-c about common longitudinal axis 99, once inlet portion 90a has penetrated outlet portion 90c. Locking portion 90b can be provided to complete the montage of valve workpiece 350 within test container 90. To this purpose, locking portion 90b has a passage 91 b for inlet duct 92a, so that locking portion 90b can be caused to slide concentrically along inlet duct 92a and can be concentrically arranged about inlet portion 90a. Locking portion 90b and outlet portion 90c can also have a screwed or snap-fit mutual tightening means.

[0082] In an embodiment, as shown in Figs. 41 and 42, the flow-blocking device 98 may comprise a container 98a such as a tank containing a liquid 98b, arranged so that outlet opening 91 c is located, under conditions of no flow and stillness of liquid 98b, at a depth h corresponding to a column pressure of liquid 98b equal to the flow blocking pressure. Container 98a is configured to allow an observer to see whether or not test gas flow G is present in liquid 98b, figure 42,or not, figure 41 , thereby providing a means for detecting and notifying the outflow of test gas G.

[0083] In one embodiment, pressure-measuring device 94 is configured to generate a pressure signal, regulation valve 96 is provided with an actuator, not shown, configured to receive a control signal and arranged to change an opening degree of regulation valve 96 responsive to the control signal, and a step S16 is also provided of prearranging a pressure regulator 95 configured to receive a test pressure setting, besides the pressure signal generated by pressure-measuring device 94, and further configured to generate the control signal, and to transfer the latter to the actuator of regulation valve 96 so as to realise a pressure control loop for pressure Pr. However, the regulation of pressure P can be performed manually by an operator.

[0084] According to Figs. 41 -45, step S20 of verifying design sealing pressure Pscomprises in turn a step \of introducing test gas G into test container 90 at a test pressure Pr that is increased over time from a minimum value Pmin, lower than design sealing pressure Ps, up to design sealing pressure Ps, as shown in the diagram in Fig. 43. The pressure increase can be achieved directly by an operator by progressively increasing the opening of pressure control valve 96, or by progressively increasing the set-point pressure in pressure regulator 95, if present.

[0085] In a possible embodiment, as shown in the example of Fig. 43, the increase in test pressure Pr during introduction step S21 of test gas G may be achieved by setting an automatic set-point pressure ramp 101 in pressure regulator 95, if the latter is configured accordingly.

[0086] Then, the test step S20 includes a verify according to step S22 follows of waiting a detection time ta, at which a step S23 is performed of detecting pressure P upstream of valve body 350, by means of pressuremeasuring device 94, and then according to subsequent step S24 of comparing the detected upstream pressure P with design sealing pressure Ps.

[0087] In particular, if comparison step S24 indicates that upstream pressure P has become significantly lower than design sealing pressure Ps, then valve workpiece 350 being tested is rejected, step S25, as it does not verify design sealing pressure Ps. For instance, once pressure Pshas been attained, it can happen that, with reference still also to Fig. 43, the pressure drops before.

[0088] As shown by the dotted lines 102 in Figure 43, this can occur both after and without reaching the design pressure Ps. Obviously, if the upstream pressure P is continuously monitored during the introduction of test gas G into the test container 90, as the upstream pressure decreases, the test gas introduction phase S21 can be interrupted and the rejection phase can be performed before the entire detection time tR has elapsed. Once implanted, such a valve workpiece 350 being tested would let urine to flow at a urine pressure tendentially lower than design sealing pressure Pr, which could possibly causing obvious discomfort to the patient. Preferably, in comparison step S24, a tolerance value is taken into account defining a minimum acceptable value and a maximum acceptable value of the detected sealing pressure. Otherwise, i.e., if once maximum detection time tR has elapsed, comparison step S24 indicates that upstream pressure P has remained substantially unchanged at design sealing pressure Ps, as shown by solid line 103 of Fig. 43, then design sealing pressure Psis validated as the sealing pressure of currently verified valve body 350, step S26.

[0089] Thereafter, in the case of a positive verification in the sense of step S26,or regardless of the above, step S30 of verifying design opening pressure Po can be performed, comprising a new step S31 of increasing test pressure Pr of test gas G. During test pressure increase step S31 a step S32 is carried out of awaiting / verifying the presence of an outlet flow of test gas G through outlet port 91 c of test container 90, for example by observing whether or not a bubbling gas develops through liquid 98b contained in the tank 98a. If such an outlet flow is not detected before the upstream pressure P reaches the design opening pressure Po, then valve workpiece 350 being tested is rejected, step S33, as it does not verify the design opening pressure. The hypothetical behaviour of such a valve workpiece is shown by the dotted curves in Figure 44. Once implanted, such a valve workpiece 350 being tested would open at a urine pressure higher than design opening pressure Po, causing obvious discomfort and / or harm to the patient due to blader overpressure. If, on the contrary, the outlet flow of test gas G is sensitively detected before the upstream pressure P reaches the design opening pressure Po, as shown by the solid curve in Fig. 44 in combination with Fig. 42, then exemplary 350 is accepted, step S34. The fluctuating upstream pressure shown in Figure 44 depends on the establishment of cycles of partialopening / closing of the valve body sample, as long as the test gas G is supplied at a given set pressure.

[0090] It should be noted that Figures 41 and 42, considered one after the other, correspond to the execution of the verification phases S20 and S30 of the sequential design holding and opening pressures, i.e. in a single supply of test gas G to the test container 90, while Figures 43 and 44 may refer to the same verification phases S20 and S30 performed separately, i.e. both starting from a substantially ambient upstream pressure P.

[0091] The above description of embodiments and modifications of the invention is capable of showing the invention from a conceptual point of view in such a way that others, using the prior art, will be able to change and / or adapt in various applications such specific embodiments and modifications without further research and without departing from the inventive concept, and, therefore, it is understood that such adaptations and changes will be considered as equivalents of the described embodiments and modifications. The means and materials for realising the various functions described may be of various kinds without departing from the scope of the invention. It is understood that the expressions or terminology used are purely descriptive and, therefore, not limitative.

Claims

CLAIMS1. An endo-urethral prosthesis (1.1 a-m) comprising a proximal part (2) and a distal part (4), wherein said proximal part (2) comprises: a proximal tubular portion (24) configured to be arranged within a patient's urethra (7), and- a proximal stent (21 ) configured to be reversibly fixed to an inner wall (8) of a urethra-vesical lumen (6-7); wherein said distal part (4) comprises: a distal tubular portion (46) configured to be arranged within said urethra (7), and a distal stent (49) configured to be reversibly fixed to said inner wall (8) of said urethra (7), wherein: said proximal tubular portion (24) and said distal tubular portion (46) define a rigid longitudinal duct (5) arranged to convey urine (100); a valve body (150,150a-m) is fluid-tightly arranged within said longitudinal duct (5) and includes a stopper portion (156) comprising resilient walls (155) separated from each other by a plurality of through slits (157) converging at a convergence point (159), and wherein said stopper portion (156) is configured for: resisting a differential pressure (AP) acting on a face of said stopper portion facing said proximal stent (21 ), and maintaining a closed configuration in which said resilient walls (155) are contiguous to each other along said through slits (157), as long as said differential pressure (AP) does not exceed a predetermined opening pressure (P*) of said valve body (150,150a-m), and for collapsing from said closed configuration, in which said urine (100) cannot pass through said longitudinal duct (5), to an open configuration, in which said resilient wall (155) are deformed and spaced apart, so that said urine (100) can pass through said longitudinal duct (5), when said differential pressure (AP) becomes higher than said opening pressure (P*),returning from said open configuration to said closed configuration when said differential pressure (AP) becomes again lower than said opening pressure (P*), in such a way that said patient, by causing an own abdominal pressure to increase, can cause said differential pressure (AP) to exceed said opening pressure (P*) and thus cause said configuration of said stopper portion (150,150a-m) to turn from said closed configuration to said open configuration, wherein said valve body (150,150a-m) is arranged within at least one portion of said proximal tubular portion (24) and said distal tubular portion (46), characterised in that said resilient walls (155) include at least one differently flexurally rigid resilient wall that has a flexural rigidity (155a-f) different from the flexural rigidity of the other resilient walls (155).

2. The endo-urethral prosthesis according to claim 1 , wherein said differently flexurally rigid resilient wall is made of a material having an elastic modulus higher or lower than said other resilient walls (155).

3. The endo-urethral prosthesis (1 a-d) according to claim 1 , wherein said differently flexurally rigid resilient wall (155a-f) and said other resilient walls (155) are integrally made of materials having a same elastic modulus, in particular they are made of a same material, and said differently flexurally rigid resilient wall (155a-f) has at least one section whose thickness is greater or lower than corresponding sections (151 ) of said other resilient walls (155).

4. The endo-urethral prosthesis according to claim 3, wherein said differently flexurally rigid resilient wall (155a / b) has at least one protuberant portion (151 a) and / or a recessed portion (151 b) with respect to its own surface.

5. The endo-urethral prosthesis () according to claim 3, in which said differently flexurally rigid resilient wall (155c-f) has said greater / lower thickness all over its own extension.

6. The endo-urethral prosthesis (1 g,1 h) according to claim 1 , wherein said differently flexurally rigid resilient wall (155g / h) and said other resilient walls (155) are integrally made of materials having a same elastic modulus, inparticular they are made of a same material, and said differently flexurally rigid resilient wall (155g / h) has at least one section (151g / h) with a curvature different from the curvature of corresponding sections (151 ) of said other resilient walls (155).

7. The endo-urethral prosthesis (1 i) according to claim 6, wherein said section with a different curvature (151 i) comprises at least two contiguous portions (152', 152") that have different curvatures with respect to each other and that are separated by an edge portion (154).

8. The endo-urethral prosthesis (1 j-m) according to claim 1 , wherein said differently flexurally rigid resilient wall (155j-m) and said other resilient walls (155) comprise respective matrices (165) made of first materials having a same elastic modulus, in particular said matrices are made of a same first material, and a body (166j,167m) or a plurality of bodies (166k, 166£) is embedded in a matrix (165j-m), among said matrices (165), of said differently flexurally rigid resilient wall (155h-k), wherein said body or said plurality of bodies is made of a second material having an elastic modulus different from the elastic modulus of said first material or of said first materials.

9. The endo-urethral prosthesis (1j-m) according to claim 8, wherein said body or said plurality of bodies is selected from the group comprised of:- a foil (166j); a granulate material (166k); a plurality of loose fibres (166£) ; a plurality of fibres connected to form a fabric (166m).

10. The endo-urethral prosthesis (1 a-k) according to claim 1 , wherein said resilient walls (155) are symmetrically arranged with respect to a central longitudinal axis (54) of said valve body (156).

11. The endo-urethral prosthesis (1 a-k) according to claim 1 , wherein said proximal part (2) and / or said distal part (4) have a diameter set between 3 and 10 mm and a wall thickness set between 0.2 and 0.8 mm.

12. An endo-urethral prosthesis (1 n) comprising a proximal part (2) and a distal part (4),wherein said proximal part (2) comprises: a proximal tubular portion (24) configured to be arranged within a patient's urethra (7), and- a proximal stent (21 ) configured to be reversibly fixed to an inner wall (8) of a urethro-vesical lumen (6-7); wherein said distal part (4) comprises: a distal tubular portion (46) configured to be arranged within said urethra (7), and a distal stent (49) configured to be reversibly fixed to said inner wall (8) of said urethra (7), wherein said proximal tubular portion (24) and said distal tubular portion (46) define a rigid longitudinal duct (5) arranged to convey urine (100); wherein said endo-urethral prosthesis (1 n) further comprises a single valve body (150,150a-m) fluid-tightly arranged within said longitudinal duct (5) and includes a stopper portion (156) comprising resilient walls (155) separated from each other by a plurality of through slits (157) converging at a convergence point (159), and wherein said stopper portion (156) is configured for: resisting a differential pressure (AP) acting on a face of said stopper portion facing said proximal stent (21 ), and maintaining a closed configuration in which said resilient walls (155) are contiguous to each other along through skits (157), as long as said differential pressure (AP) does not exceed a predetermined opening pressure (P*) of said valve body (150,150a-m), and for collapsing from said closed configuration, in which said urine (100) cannot pass through said longitudinal duct (5), to an open configuration, in which said resilient walls (155) are deformed and spaced apart, so that said urine (100) can pass through said longitudinal duct (5), when said differential pressure (AP) becomes higher than said opening pressure (P*), returning from said open configuration to said closed configuration when said differential pressure (AP) becomes again lower than said opening pressure (P*), in such a way that said patient, by causing an own abdominal pressure toincrease, can cause said differential pressure (AP) to exceed said opening pressure (P*) and thus cause said configuration of said stopper portion (150,150a-m) to turn from said closed configuration to said open configuration, characterised in that said endo-urethral prosthesis further comprises a tubular intermediate part (3) interposed in a detachable manner between said proximal part (2) and said distal part (4), and in that said valve body (150,150a-m) is arranged within said tubular intermediate part (3).

13. A method for verifying a design sealing pressure (Ps) and a design opening pressure (Po) of a valve workpiece (350) of an endo-urethral device, said valve workpiece (350) comprising a stopper portion (356) in which a plurality of resilient walls (355) are separated from each other by a plurality of through slits (357), said method comprising the steps of: prearranging (S11 ) a source (S) of a test gas (G) at a predetermined source pressure (Pi); mounting (S17) said valve workpiece (350) in a mounting site (97) of a test container (90) having an inlet port (91 a) for said test gas (G) and an outlet port (91 c) for said test gas (G), wherein said step of mounting is performed in such a way to form a gas-tight seal between said inlet port (91 a) and said outlet port (91 c); introducing (S21 ) said test gas (G) into said test container (90) at a predetermined test pressure (Pr) increasing over time from a minimum value (Pmin) that is lower than said design sealing pressure (P(S)) up to said design sealing pressure (Ps); waiting (S22) until a predetermined detection time (tn) has elapsed; detecting an upstream pressure (P) upstream of said valve workpiece (350); comparing (S23) said upstream pressure (P) with said design sealing pressure (Ps); if said comparison step indicates that said upstream pressure (P) has become significantly lower than said design sealing pressure (PS), rejecting (S24) said valve workpiece (350);if, instead, after said maximum detection time (tn) said comparison indicates that said upstream pressure (P) remains substantially equal to said design sealing pressure (PS), validating (S25) said design sealing pressure (PS); - increasing (S31 ) said test pressure (Pr) and, simultaneously, awaiting / detecting (S32) a presence of an outlet flow of said test gas(G) through said outlet port (91 c) of said test container (90); if said outlet flow is not detected before said upstream pressure (P) reaches said design opening pressure (Po), - rejecting (S33) said valve workpiece (350); if, instead, said outlet flow is detected before said upstream pressure (P) reaches said design opening pressure (Po), validating (S34) said design opening pressure (Po), and accepting said valve workpiece (350).

Images