WO2015071472A1

WO2015071472A1 - Orthotopic prosthesis of artificial bladder which integrates ureteral stents

Info

Publication number: WO2015071472A1
Application number: PCT/EP2014/074811
Authority: WO
Inventors: Antonio Sambusseti
Original assignee: Antonio Sambusseti
Priority date: 2013-11-18
Filing date: 2014-11-17
Publication date: 2015-05-21
Also published as: ITMI20131910A1

Abstract

Orthotopic prosthesis of artificial bladder (100), for human and veterinary use, equipped with specific upper means (10) and lower means (20) for connecting and fastening the ureter/urethra to said prosthesis, said means being made of silicone covered completely with a microfilm of pyrolytic turbostratic carbon, where the upper connection means (10) integrate a tubular element (6a) which acts as a ureteral stent, said element (6a) being distal with respect to the surface of said prosthesis (100) and having a length at least 1/3 of the overall length of the ureter (13).

Description

ORTHOTOPIC PROSTHESIS OF ARTIFICIAL BLADDER WHICH INTEGRATES URETERAL STENTS

DISCLOSURE

The present invention refers to an orthotopic prosthesis of artificial bladder which integrates ureteral stents and/or urethral stents and relative system of anastomosis for ureter/urethra to said prosthesis. More specifically, the present invention refers to an orthotopic prosthesis of artificial bladder, equipped with means for connecting ureters and/or urethra to said artificial bladder which integrate ureteral stents completely covered with pyrolytic turbostratic carbon. Some urological diseases (calculi, strictures, tumours) can cause obstruction of the ureteral channel consequently obstructing the normal outflow of urine and causing kidney impairment due to distension of the renal cavities that do not empty, partly or completely, the urine which is produced. In the case of calculi and/or strictures, to restore opening of the lumen and maintain its patency, very often a ureteral stent (ureteral catheterization) is positioned throughout the length of the ureter, allowing the renal cavities to communicate freely with the bladder, once it has been inserted by means of retrograde stenting starting from the urethra and running throughout the ureter, preventing the occlusion thereof.

The most commonly used ureteral catheter has a length of approximately 26-30 cm (for adults) with a diameter of approximately 4-10 Ch; the two ends are curled (double J or pigtail) to prevent displacement, thus allowing permanent stability inside the urinary tract (autostatic stent).

The ureteral stent can remain in place for a brief period (days or weeks) or for longer (weeks or months) and must be periodically replaced (approximately every six months) to prevent fractures inside the catheter or the formation of scale. The need to replace the stent after a certain period of time undoubtedly represents a considerable drawback which is much more significant if the patient already has an artificial bladder, indicating the existence of considerable urological problems. The above also applies to urethral stents.

The object of the present invention is to overcome, at least partly, the drawbacks of the known art by providing flexible ureteral and/or urethral stents, adapted in particular for patients with artificial bladder, which are effective and simple to produce, and which do not require periodic replacement.

A further object is to provide said stents which are not subject to fractures when implanted or the formation of scale. These and further objects are achieved by the orthotopic prosthesis of artificial bladder according to the invention which integrates ureteral and/or urethral stents having the characteristics listed in the attached independent claim 1.

Advantageous embodiments of the invention appear in the dependent claims.

One object of the present invention concerns an orthotopic prosthesis of artificial bladder, for human and veterinary use, provided with specific upper and lower means for connecting and fastening the ureter/urethra to the artificial bladder, where said upper fastening means each integrate a ureteral stent and/or said lower fastening means integrate a urethral stent.

The lower connecting means comprise a hollow frustoconical element which is biocompatible due to it being completely covered, inside and outside, with specific materials resistant to urine and adapted to prevent the fusion of said prosthesis with the surrounding tissues, preferably a microfilm of pyro lytic turbostratic carbon.

Said frustoconical element is integral with the prosthesis and protrudes from it towards the outside thus allowing connection of the urethra to the artificial bladder, after the urethra has been partially inserted inside said frustoconical element and sutured at the lower base thereof.

Also the upper means comprise a hollow frustoconical element which protrudes from said prosthesis towards the outside: said frustoconical element is connectedto the respective ureter by means of suture, after said ureter has been partially inserted inside said frustoconical element.

Within each frustoconical element of said upper connection means, a respective tubular element of very elongated shape is arranged, coaxially with said frustoconical element; said tubular element, hollow inside and optionally perforated laterally, is adapted to act as a ureteral stent. Its length is such that it projects considerably from the hollow frustoconical element.

In particular, the hollow tubular element relative to the ureters (upper tubular element) has, in the proximity of its insertion point on the artificial bladder, a longitudinal portion with enlarged section thus fitting and inserting on a projecting shank belonging to a frustoconical element which is arranged within the bladder and integrally fastened to it. In the area of the surface of the bladder between the frustoconical element and the tubular element relative to the ureters, through holes are provided which have the purpose of draining the portion of the urine flow which is not conveyed by the upper tubular element so as to avoid any stagnation of urine in the above-mentioned area which could cause infections.

Each of the two hollow tubular elements for connection of the ureters is furthermore arranged on the bladder with its longitudinal axis inclined with respect to the vertical axis of the prosthesis, analogously to a natural bladder, and in a position and at a certain horizontal distance from each other such as to form, together with the bottom hole for urine outflow towards the urethra, a substantially triangular area which lies on an oblique plane with respect to the longitudinal axis of the prosthesis, analogous to the bladder trigone (the space between the two ureteral orifices and the internal urethral orifice) of a natural bladder. In said arrangement, the bottom opening for insertion of the urethra occupies the vertex of said triangular area while the two openings for insertion of the ureters delimit the base which is posterior with respect to said vertical axis, thus forming said bladder trigone.

The upper and lower means are made of a flexible biocompatible material, for example silicone covered completely with a microfilm of pyrolytic turbostratic carbon. The orthotopic prosthesis of artificial bladder is generally formed of a container in the form of a collapsible pouch or balloon, made of a multilayer membrane in soft elastic synthetic material, such as silicone, optionally radio-opaque, made biocompatible by means of complete covering, inside and outside, with specific materials resistant to urine and adapted to prevent the fusion of said prosthesis with the surrounding tissues, preferably a microfilm of pyrolytic turbostratic carbon.

Since said prosthesis is made of soft multilayer silicone, it can be emptied by means of simple compression of the lower abdomen (compressable bladder). The advantage of the ureteral stent integrated in the bladder is that it avoids the operation of retrograde stenting in which the double J stent is inserted starting from the urethra and running throughout the ureter.

Furthermore, due to the fact that said stent is made of the same material as the artificial bladder, it is not necessary to replace it given that it can remain in place permanently like the artificial bladder.

Further characteristics of the invention will become clearer from the following detailed description, referring to a purely exemplifying and therefore non-limiting embodiment illustrated in the accompanying drawings, in which:

Figure 1 is an enlarged section view of the upper connection means (in particular the hollow tubular element with relative sleeve) mounted on the prosthesis and connected to a ureter (illustrated by the broken line); Figure 2 is an exploded view of the upper connection means of Fig.1;

Figure 3 is a section view showing the lower connection means (in particular the hollow tubular element with relative sleeve) mounted on the prosthesis and connected to a urethra (illustrated by the broken line);

Figure 4 is an overview in vertical section of the multilayer orthotopic prosthesis of artificial bladder which is fitted with the upper and lower tubular connection elements of Figg. 2-3 before fitting of the respective sleeve. Fig. 1 and 3 illustrate a partially interrupted section of an orthotopic prosthesis 100 of artificial bladder with a spherical balloon-like shape known in the art, consisting of a silicone membrane 1 which will be described in detail subsequently.

Said membrane 1 has two upper openings or holes 2 (fig.l) and one bottom opening or hole 3 (fig.3), all three substantially circular, with diameter varying from 22 mm to 26 mm, which are covered by a respective flat cover or cap, at the top 2a (fig.l) or at the bottom 3a (fig.3).

On each of said two upper caps 2a a through hole 4 (fig. 1) is obtained, with diameter of approximately 10 mm, for the insertion of elements forming part of upper connection means which will connect said artificial bladder 100 to the respective ureter 13; likewise on said bottom cap 3a a through hole 5 (fig. 3) is obtained, with diameter of approximately 10 mm, for the insertion of elements of lower connection means which will connect said artificial bladder 100 to the urethra 18.

Said covers or caps 2a, 3a constitute substantially flat portions of the prosthesis 100 which facilitate drilling, mounting and fastening of the upper and lower connection means to the artificial bladder. Each of said upper covers 2a has around the hole 4, at an appropriate distance from it, one or more through holes 16 with diameter much smaller than that of the hole 4, which have the purpose of avoiding any stagnation of urine in the area which could cause infections. Said holes generally have a diameter of approximately 0.3 cm. The appropriate upper connection means of the prosthesis to the ureter 13 are indicated overall in Fig. 2 by the reference number 10 and will be described below. They comprise a biocompatible hollow tubular element 6 made of silicone, which has a first tubular portion 6a, distal with respect to the surface of the membrane 1 of the balloon 100 and a second tubular portion 6b, proximal to the surface of the membrane 1 of the balloon 100, which has a section with much larger diameter than that of the first portion 6a thus resulting in a tubular element 6 having a portion with enlarged section 6b in the vicinity of the surface of the prosthesis 100.

Said first portion 6a, below also indicated as "stent tube", has a length of at least approximately 10 cm and an external diameter of between 6 and 9 Fr (French), preferably 6 Fr (= 3 mm) and thickness of approximately 0.25 mm. The internal diameter of said portion 6a is 2-2.5 mm.

Said element 6a therefore shows a length equal to at least 1/3 of the overall length of the ureter. Said first tubular portion 6a is furthermore provided with one or more side slits 12, or through holes, adapted to facilitate the outflow of the urine inside the prosthesis 100.

Said second portion 6b, which acts as a base for the stent tube 6a, has a length of approximately 2 cm, an external diameter of approximately 4.5-4 mm, preferably 4 mm, with a thickness of approximately 2.5 mm.

Said second portion 6b with section larger than the first portion 6a is inserted in forced coupling on a shank 9 projecting from a frustoconical element 7 provided with an axial channel 40 having an internal diameter of approximately 0.5 cm.

Said cone element 7 with axial channel 40 has a flat enlarged base 8 intended to couple by means of gluing with the upper cover 2a of the artificial bladder 100 thus fastening integrally with said upper cover 2a which, in turn, is integral with said prosthesis 100 via gluing means. Said enlarged flat base 8 has a number of through holes 16' intended to be aligned coaxially with a plurality of through holes 16 positioned on the upper cover 2a thus forming a plurality of through channels adapted to discharge inside the prosthesis 100 any urine stagnating on the surface of the prosthesis 100, a phenomenon which could spread bacteria: in this way discharge of the urine into the prosthesis will be complete, avoiding the persistence of stagnating liquid.

In figure 1, the hole 4 on the upper cover 2a has been illustrated with larger dimensions than actual ones in order to better illustrate the construction of the connection means between ureter and prosthesis, although it has a diameter such as to be in contact with the second portion 6b of the tubular element 6.

The element 7 having the shape of a truncated cone is one single frustoconical piece which has a circular base 8 enlarged with respect to the maximum diameter of the cone 7: said enlarged base 8 is intended to be glued to the inner surface of the cover 2a, after the hollow shank 9 has been inserted into the hole 4 made on the upper cover 2a.

Said frustoconical element 7 which is integral with its enlarged base 8 is made of silicone, preferably radio-opaque, with hardness of approximately 50 Shore.

In a preferred embodiment said frustoconical element 7 has a height of approximately 10 mm, an enlarged base 8 with diameter of approximately 20 mm, a shank 9 with height of approximately 4 mm, with an internal diameter of approximately 1.8 mm.

Said upper connection means 10 furthermore include a frustoconical containment element 14, internally hollow, to be arranged outside the tubular element 6 and fixed by means of gluing to the surface of the cap 2a of the prosthesis 100, arranged outside the hollow tubular element 6: once the hollow tubular element 6 has been inserted inside a portion of ureter 13, said frustoconical containment element 14 will be fixed to said ureter 13 by the application of some sutures 15, at the annular smaller base 32 of said containment element 14. Said containment element 14 is normally shorter than the tubular element 6 and has substantially the same height as the portion with enlarged section 6b of the tubular element 6, generally approximately 2 cm. The elements that constitute said upper connection means 10 are assembled after positioning each upper cover 2a over the respective upper hole 2 of the prosthesis and having made the hole 4 on said cover 2a: the frustoconical element 7 is then arranged within the bladder 100 leaving only the shank 9 of the frustoconical element 7 to protrude from the membrane 1, subsequently inserting the tubular element 6 over said shank 9 in forced coupling thus making said elements all integral with one another and at the same time integral with the prosthesis 100.

To facilitate the fastening of said ureters 13 to said frustoconical element 14 a reinforcement is provided in the suture zone at its annular smaller base 32 which acts as an inlet for the ureter 13 and at the lateral surface below said smaller base 32. Said reinforcement consists of a Dacron ring-shaped mesh.

Furthermore on the smaller base 32 of said frustoconical element 14, in the area reinforced with the Dacron mesh, at least two cuts 30 are provided, diametrically opposed, to facilitate the enlargement of the annular smaller base 32 for inlet of the ureter 13 during the operation of connecting the ureter to the prosthesis 100.

In particular said Dacron mesh serves to fasten the upper end of the cone (smaller base 32) to the tunica adventitia, i.e. to the superficial outer membrane that envelops the ureters, so that the fastening suture does not have to be passed through the lumen of the ureters (and urethra) i.e. inside the lumen, in order to avoid creating infections and stenoses and occlusions (the suture must never pass inside the lumen).

During surgery the ureters, which have a diameter of approximately 3-4 mm, are practically fitted over the stent tubular portion 6a until they reach the inlet of the frustoconical element at its smaller base 32, then proceeding with suture of the ureter to said frustoconical element as described above. The means connecting the urethra to the prosthesis, indicated overall by the reference number 20, are arranged on the bottom of the prosthesis 100 as illustrated in fig. 3

Said connecting means 20 are substantially similar to the upper connecting means 10 and are composed of a biocompatible hollow tubular element 17 to be inserted inside a portion of urethra 18 (illustrated by the broken line in fig. 3) also adapted to act as a stent, but for urethra.

Said hollow tubular element 17, also indicated as bottom tubular element, has an enlarged base 21, perpendicular to the longitudinal axis of said tubular element 17; its outer surface, from which its tubular portion detaches, is intended to be glued to the surface of the cover 3 a facing towards the inside of the prosthesis 100 as illustrated in fig. 3, thus rendering the tubular element 17 integral with the prosthesis 100. In a preferred embodiment, said bottom hollow tubular element 17 has a length of approximately 50 mm, an external diameter of approximately 10 mm, a thickness of approximately 1 mm, and an enlarged circular base 21 with diameter of approximately 20 mm. Said base hollow tubular element (tube) 17 is one single piece with its base 21 and is made of silicone, preferably internally reinforced with a Dacron mesh inserted into the thickness, obtained by means of known technique, for example moulding, dipping or similar techniques which allow said mesh to be incorporated in a layer of silicone. Also in this case, the lower connection means 20 are provided with a bottom frustoconical coupling 22, arranged around the bottom tubular element 17, to which the urethra 18 will be fixed 18 by means of sutures 19, at its smaller base 23, analogously to fastening of the ureters, after inserting the tubular element 17 inside a portion of urethra 18.

The coupling 22 is also made of silicone and has the same characteristics as the coupling 14 described above, except for the dimensions.

Also in this case, the Dacron mesh allows the urethra 18 to be sutured more efficiently and securely to the coupling 22, avoiding possible tearing and breaking of the element itself: since the suture thread has dimensions of 4-0 Ch it is more rigid than a cone made of silicone only, having the same thickness. Also in this case said Dacron mesh serves to fasten the lower end of the cone (smaller base 23) to the superficial outer membrane which envelops the urethra so that the fastening suture does not have to be passed through the lumen.

During surgery the urethra, which has a diameter of approximately 5 mm, is practically fitted over the tubular portion 17 until it reaches the inlet of the frustoconical element at its smaller base 23, then proceeding with suturing of the urethra to said frustoconical element as described above.

The orthotopic prosthesis of artificial bladder 100 according to the invention has a balloon-like spherical shape and is known in the art, for example the one described in the patent IT 1.401.467 in the name of the Applicant, here fully incorporated for reference.

Said balloon 100 is collapsible so that the filling and emptying mechanism of the prosthesis, deriving from it, functions due to the effect of the different pressure between the air within the prosthesis and the air outside the prosthesis: in fact, the present prosthesis is emptied by simple compression of the lower abdomen.

The capacity of said prosthesis is generally between 400 and 900 cm .

Said balloon 100 consists of a membrane 1 made of soft, flexible elastic silicone, so that it can be compressed, deflated or collapsed and has a high distendibility.

Said membrane 1 generally has a thickness of approximately 600-1200 micron according to the volume of the prosthesis, given that when the volume is increased, the thickness must also be increased proportionally to guarantee collapsibility.

Said membrane is preferably a multilayer membrane, generally consisting of 20 layers of silicone, each having a thickness of approximately 30 micron. Said multilayer membrane 1 is preferably produced using the method described in the patent application WO2007/039159 fully incoiporated here for reference.

In particular the multilayer membrane 1 is obtained from the silicone raw material, by means of a work process called dipping. By means of dipping equipment, a ball or bag is created starting from a single layer of silicone, overlaying other layers on each layer until the desired thickness is obtained, for example approximately 600 micron.

Said multilayer dipping technique consists in producing the first layer, evaporating it with cyclohexane for 10 minutes, overlaying the second layer, evaporating it again with cyclohexane for 10 minutes, and so on until the last layer. At this point the stratified silicone membrane 1 is in a semi-fluid state: it is then placed in a vulcanization oven, at a temperature of approximately 150°C and for a time varying from 30 minutes to 1 hour, according to the required size of the prosthesis. After the vulcanization cycle, the multilayer silicone membrane 1 has an optimal softness and elasticity, and is no longer in a semi-fluid state.

The silicone used can consist, for example, of silicone elastomer copolymers with high elongation and high tensile strength, for example the copolymers of dimethyl- and metavinyl siloxane, reinforced with silicon. Preferably a medical silicone is used, for example the one known as MED 4735™ and marketed by the company Nusil Technology.

Furthermore, radio-opacifying additives such as barium sulphate, titanium dioxide and similar are preferably added to the silicone, to allow detection and display of the prosthesis with the techniques normally used such as X-rays, ultra-sound scanning and other analysis systems that use radio waves.

In a preferred embodiment, said balloon 100 has a thickness of 0.6 mm and a diameter between approximately 72 and 74 mm.

After obtaining said silicone balloon 100, a longitudinal opening (not illustrated), the two upper holes 2 and the bottom hole 3 which will be covered by a flat cover or upper cap 2a and by a flat cover or bottom cap 3 a respectively, as said previously, are made on said balloon. The process of obtaining the present prosthesis 100 is the following: firstly the silicone balloon is obtained 100, preferably multilayer, for example via the dipping process described above. Subsequently, the upper holes 2 and the bottom holes 3 on the surface of said balloon 100 and a longitudinal opening are obtained. Then the respective cap covers 2a and 3 a are applied and fastened, by gluing, over the respective hole 2, 3 covering it completely. A microfilm or layer of highly biocompatible biomaterial is then applied on the outer surface 30 and subsequently on the inner surface 40 of the balloon 100 according to the procedure already described in the patent IT 1.401.467 in the name of the Applicant, fully incorporated here for reference. The highly biocompatible biomaterial is, for example, pyrolytic turbostratic carbon or diamond-like carbon, preferably pyrolytic turbostratic carbon, and can have a thickness for example of approximately 0.2-0.3 micron if applied by PVD (physical vapour deposition). This avoids both the risk of adhesion of the fibrotic capsule to the prosthesis 100 and internal corrosion of said prosthesis 100 due to the action of the urine on the non-coated silicone.

The upper openings or holes 4 have a size generally between 5 and 15 Charriere (1 Ch = 1/3 mm) such as to allow the insertion and easy passage of the shank 9 of the cone element 7, after the latter has also been covered with pyrolytic turbostratic carbon or diamond-like carbon.

In fact, before being coupled to the balloon 100, also said upper connecting means 10 and lower connecting means 20 must be covered internally and externally with the same film applied to the inner and outer surface of the balloon 100.

In particular, the frustoconical element 7 (like the bottom tubular element 17 and the upper tubular element 6) is covered with pyrolytic turbostratic carbon or diamond-like carbon, both inside and outside, analogously to the balloon 100, except for the upper surface 8' of the enlarged base 8 of said frustoconical element 7 since it is intended to be glued to the cover 2a.

The gluing mentioned above is preferably obtained with a silicone glue. Numerous detail modifications and variations can be made to the embodiment of the innovation described above obvious for a person skilled in the art, falling within the scope of the innovation expression by the attached claims.

Claims

1. Orthotopic prosthesis of artificial bladder (100), for human and veterinary use, equipped with specific upper means (10) and lower means (20) for connecting and fastening respective ureters/urethra (13; 18) to said prosthesis, said means being made of silicone covered completely with a microfilm of pyrolytic turbostratic carbon,

said lower connecting means (20) comprising a hollow tubular element (17) and a hollow frustoconical element (22) intended to be sutured to said urethra (18) for fixing said urethra (18) to said prosthesis (100),

said upper connecting means (10) comprising

at least one hollow frustoconical element (14) of containment protruding outwards from said prosthesis, intended to be sutured to said ureter (13) for fixing said ureter to said prosthesis (100),

and

at least one respective elongated hollow tubular element (6), arranged within said frustoconical element (14), which projects from it towards the outside of said prosthesis, adapted to be inserted inside a portion of a respective ureter (13),

characterized in that said elongated hollow tubular element (6) of said upper fastening means (10) and/or said lower fastening means (20) integrate a tubular element of elongated shape (6a, 17) so as to act as ureteral stent and/or urethral stent, said upper means (10) and lower means (20) being made of silicone completely covered with a microfilm of pyrolytic turbostratic carbon.

2. Orthotopic prosthesis of artificial bladder (100) according to claim 1 wherein said fastening upper means (10) integrate a tubular element of elongated shape (6a) so as to act as ureteral stent, said element (6a) being distal to the surface of said prosthesis (100) and having a length equal to at least 1/3 of the overall length of the ureter (13).

3. Orthotopic prosthesis of artificial bladder (100) according to claim 1 or 2 wherein said stent tubular element (6a) is an integral portion of said tubular element (6), the remaining portion (6b) thereof which is proximal to the surface of said prosthesis (100) having a larger diameter and shorter length than said first stent tubular portion (6a).

4. Orthotopic prosthesis of artificial bladder (100) according to any one of the preceding claims wherein said stent tubular portion (6a) is also provided with one or more side slits (12) for outflowing urine inside said prosthesis (100).

5. Orthotopic prosthesis of artificial bladder (100) according to any one of the preceding claims wherein through holes (16) are provided on a portion of the prosthesis surface delimited by the containment element (14) of the upper connecting means (10) and by the tubular element (6) that integrates said stent (6a).

6. Orthotopic prosthesis of artificial bladder (100) according to any one of the preceding claims wherein said remaining portion (6b) having a greater section is inserted in forced coupling on a shank (9) projecting from a frustoconical element (7) equipped with an axial channel (40) extending through it and an enlarged flat base (8) intended to be fixed to said prosthesis (100).

7. Orthotopic prosthesis of artificial bladder (100) according to any one of the preceding claims wherein said hollow frustoconical containment element (14) has a reinforced annular smaller base (32) adapted to fastening the ureter (13) to it by means of sutures (15).

8. Orthotopic prosthesis of artificial bladder (100) according to any one of the preceding claims in which one or more cuts (30) are provided at the smaller base (32) of said hollow frustoconical containment element (14).

9. Orthotopic prosthesis of artificial bladder (100) according to any one of the preceding claims wherein said hollow frustoconical containment element (14) has a length substantially equal to that of the enlarged portion (6b) of the tubular element (6).