WO2011018300A1

WO2011018300A1 - Reabsorbable concave plate (scaffold) for the replacement of a portion of bladder wall following partial cystectomy

Info

Publication number: WO2011018300A1
Application number: PCT/EP2010/060329
Authority: WO
Inventors: Antonio Sambusseti
Original assignee: Antonio Sambusseti
Priority date: 2009-08-14
Filing date: 2010-07-16
Publication date: 2011-02-17
Also published as: IT1395172B1; TN2012000065A1; AP3266A; ZA201201071B; AP2012006158A0; MA33584B1; ITMI20091481A1

Abstract

A concave dome-like plate (1) is described for the replacement of a portion of bladder wall, following partial cystectomy, consisting of reabsorbable polymers derived from lactic acid.

Description

REABSORBABLE CONCAVE PLATE (SCAFFOLD) FOR THE REPLACEMENT OF A PORTION OF BLADDER WALL FOLLOWING PARTIAL CYSTECTOMY

5 DESCRIPTION

The present invention relates to a concave dome-like plate (scaffold) for the replacement of a portion of bladder wall, following partial cystectomy, particularly indicated for the treatment and cure of bilharziasis.

I O

As known, when a portion of the bladder of a patient is affected by a serious disease, such as partial neoplasia or bilharziasis (schistosomiasis), said portion of the bladder must be removed to prevent the spreading of the disease to the whole bladder. The removal of said portion of the bladder creates a hole in the bladder that is usually closed

15 by using a planar patch which is sutured to the perimeter of the bladder wall which defines said hole.

Patches can usually be made of synthetic materials such as silicone for example, or a synthetic fabric such as polypropylene, as described in patent applications WO 20 2007/039160 and PCT/EP2008/006352 on behalf of the Applicant, made biocompatible by way of a coating of a layer of turbostratic pyrolytic carbon, or fatty acids of the omega- 3 family.

These patches are designed to temporarily replace the portion of the bladder removed 25 pending the regeneration of cell tissue of the bladder around the hole and therefore must be later surgically removed under anesthesia. This operation however is not always convenient to perform, especially on elderly patients who are also most prone to neoplasia of the bladder.

30 Moreover, these patches have the disadvantage of being flexible planar elements and not rigid and therefore tend to collapse without being able to conform with the rounded shape of the bladder or a part of it.

Patches in bioreabsorbable materials are also known which do not require a subsequent

35 surgery for their removal: however, also these patches present the same disadvantages as those described above. In addition, during re-absorption, this type of patch can collapse downwardly due to both the weight of the forming tissue and to the flexibility of said patch, giving rise to tissue reconstruction which tends to be flat and inconsistent with the rounded shape of the bladder or part of it. The aim of the present invention is to eliminate, at least in part, the drawbacks of the known prior art technique, providing an element, such as a patch, for the replacement of a portion of bladder wall, following partial cystectomy, that conforms to the shape of the bladder, once implanted, and that does not require subsequent surgery for its removal. Another aim of the present invention is to provide such an element that is also practical for the surgeon and at the same time easy to produce,

Yet another aim of the present invention is to provide such an element that is reliable without presenting possible leakage of liquid.

These aims are achieved by a dome-like plate according to the invention having the characteristics listed in the attached independent claim 1.

Beneficial implementations of the invention appear within the dependent claims.

The plate (scaffold) according to the invention, for the replacement of a portion of bladder wall following partial cystectomy, consists of a sheet of reabsorbable material, defined herein as bioreabsorbable, having rounded corners in the form of a concave dome with the concave side facing the interior of the bladder to ensure the growth of cellular tissue with essentially the same rounded anatomy of the removed part of the bladder upon which the plate is applied.

Said plate is equipped with a plurality of holes, equally spaced, and positioned on the outer edge of the plate allowing the passage of the suture thread meant to fix the plate to the bladder.

Additional features of the invention will appear clearer from the following detailed description with reference to a purely exemplifying embodiment and therefore not limiting illustrated in the attached drawings, in which:

Figure 1 is a perspective view of the concave plate according to a first embodiment of the invention; Fig 2 is an external plan-view of the plate of fig.l ;

Fig 3 is a bottom-view of the plate of Fig. 2;

Fig 4 is a right-side view of the plate in Fig. 2;

Fig 5 is a sectional view taken along the line V-V in fig. 2.

With reference to the Figures listed above, a plate is described according to the invention indicated as a whole with the reference number 1. In Figures the plate 1 is represented with a square section, although this form is not binding for the purposes of the present invention. A square plate 1 preferably has a 70 x 70 mm dimension.

The plate 1 comprises a sheet composed of a bioreabsorbable polymer, e.g. polymers or copolymers based on lactic acid (L-, D-, racemic, or dimer, esters, etc. or combinations thereof). A particularly preferred acid is poly(D-lactide) or polyester copolymer poly(L-lactide-co- D,L-lactide) (PLDLA, or otherwise identified as PLDL or PLLA/PDLLA). This polyester is a copolymer having a monomeric composition L-lactide: D,L-lactide of about 70:30. It is also possible to use a PLDLA copolymer as defined above having a different monomeric composition, for example with a monomeric content of the comonomer L- lactide between 70% and 30% (and the comonomer D,L-lactide is the complementary part to 100).

Another example of a utilizable polymer is the poly-L-D-lactic acid, preferably having a monomeric composition L-lactide: D-lactide equal to 70/30 or 50/50; or the poly(L- lactide). The latter is particularly preferred.

Said plate 1 can be obtained by molding or other known techniques normally used for the formation of curved polymer sheets. The thickness 3 of the fabric is not binding for the purposes of this invention: it is fairly thin but thick enough to ensure a sufficient rigidity of the plate 1 thus resulting in a self- supporting plate, ensuring both the resilience and flexibility needed due to movements (dilatations) of expansion and deflation of the bladder due to the filling and emptying thereof. Said thickness 3 can vary between 0.1 mm and 2 cm. In a preferred embodiment said thickness 3 is about 0.5 mm. In the square plate 1 of Figure 1 having a dimension of 70 x 70 mm, the inner radius of curvature is preferably R75 (75 mm). The holes 2 have a diameter of about 1 mm and are spaced from each other by 2.5 mm. The distance of said holes 2 from the edge 3 is of about 2.5 mm. Moreover, the radius of curvature of the rounded corners of the plate 1 in Fig. 1 is of about 0.3 mm.

Other advantageous embodiments of the plate 1 of the present invention (not represented in the figures) may provide a dimension of the sides from 30 x 30 mm to 200 x 200 mm. In this case all the other technical characteristics mentioned above such as the radius of the concavity (radius of curvature), the number of holes, the radius of the rounded corners, thus follow the dimensions of the sides and vary in proportion to the dimensions of said sides. Also the distance between the holes and that of the holes from the edges will need to vary in proportion according to the varying dimensions of the sides. Even the hole diameter may vary from a minimum to a maximum of between 0.1 and 3.0 mm.

Said plate 1 further presents a finishing of the upper surface 4 substantially equal to that of the lower surface. Upper surface 4 refers to the surface facing away from the bladder while the lower surface refers to that which faces internally towards said bladder once that the plate 1 will be applied to the bladder.

It is also possible to provide the plate 1 with one or more holes (not shown) for connecting the ureters and/or the urethra to said plate. The implementation of such holes may be accomplished according to known techniques, as described in WO 2007/039160, in relation to silicone implants on behalf of the Applicant, fully incorporated herein by reference.

The preparation of the plate 1 takes place in a controlled environment (controlled contamination) in a clean room. After processing, the plate 1 is wrapped and enclosed by a sheet of Tyvek to avoid contamination, and submitted to a sterilization cycle based on ETO (ethylene oxide).

At this point the plate 1 is ready for use in surgical procedure.

The choice of the size and thickness of the plate 1 depends essentially on the patient's age and/or metabolism. Therefore the technical characteristics mentioned above must be such as to avoid, during the process of reabsorbtion, inflammatory situations or events due to incorrect reabsorbtion time, being too rapid with respect to the metabolism of the patient. For each of the above described implementations of the plate 1 , all or some of the holes can be used for suturing: for example, one is sutured and two are not, or two are sutured and one is not, or one is sutured and one is not or all are sutured according to the discretion of the surgeon and the individual clinical case.

The plate 1 is applied to the bladder substituting the removed portion according to known surgical techniques. For example, if the portion of the bladder affected by neoplasia is far from the ureters and urethra, the surgeon removes the affected portion and to cover the removal hole a plate 1 is applied by sutures that connect the holes 2 of the plate 1 to the bladder wall surrounding the removal hole. As mentioned, in producing the plate 1 it is preferable to use the poly(L-lactide) or a copolymer poly(L-lactide-co-D, L-Iactide) (PLDLA) having a monomeric composition of 70:30. However, it is also possible to advantageously use mixtures of this polyester with other polymers deriving from lactic acid and the choice will be made according to the patient's metabolism and age. The same can be repeated for poly-L-D-lactide, where the choice of the monomeric content L-lactide: D-lactide will be made according to the patient's metabolism and age.

The suture thread is also preferably made of a reabsorbable material,, such as polymers mentioned above for the plate 1 of the present invention, preferably PLA, PLLA. The motivation for such a choice lies in the need for patches and sutures to be reabsorbed within the same timeframe. The suture thread is then inserted into a cylindrical needle ³A curved and round, including the "Bassini" types.

The passage holes 2 for suture thread do not constitute a risk of liquid leakage, as in a few hours the tissue is reconstructed. To avoid leakage of urine (liquid), the suture holes can be welded and sealed with one cc. (one drop) of surgical glue, such as Glubran 2™ normally commercially available.

One of the advantages of the plate 1 of the present invention is that it presents no risk of adhesion of the fibrous capsule to the plate as it is completely reabsorbable during the regeneration of the removed portion and therefore does not require its removal from the organ upon which it has been implanted by way of subsequent surgery. The absorption time may vary from 6 months to 2 years depending on the patient's metabolism and characteristics of the plate previously indicated. The use of plates in accordance with the present invention is particularly beneficial in the treatment of localized bladder infections such as bilharziasis, where the removal of the infected part of the bladder is sufficient for overcoming the disease, without need for subsequent treatments or surgery. In particular, with respect to patches made of synthetic material such as silicone treated with turbostratic carbon, the plate 1 of the present invention does not require re-operation after 60 days since it is reabsorbable while with respect to patches of fabric made with reabsorbable thread, the plate of the present invention has the advantage of being more rigid and dome-shaped, therefore similar to the anatomy of the bladder: thus the probability that the cellular neo-tissue that is formed during the reabsorption has a shape identical to the original anatomy of the removed portion, is enormously increased, insofar as it is moulded by the shape and profile of the part removed. By contrast, in patches of woven reabsorbable thread, this does not happen because it is subject to the risk of being crushed, collapsibility, and can be downwardly displaced giving rise to a tissue reconstruction not conforming to the original rounded shape, but rather fiat or semi- round.

To these presented embodiments of the invention numerous variations and amendments of details can be made within the skill of an expert in the art, falling within the scope of the invention expressed by the attached claims.

Claims

1. Plate (1) for the replacement of a portion of bladder wall, following partial cystectomy, equipped a plurality of holes (2) drilled in proximity of the edge (5), characterised in that it is formed by a concave dome-like sheet made up of one or more reabsorbable polymers.

2. Plate (1) according to claim 1 wherein the reabsorbable polymer is chosen from polymers or copolymers based on lactic acid (L-, D-, racemic mixture, or dimer, esters, etc., or combinations thereof).

3. Plate (1) according to claim 2 wherein the polymer is ρoly(L-lactide), or poly(D- lactide) or poiy(L-lactide-co-D,L-lactide) (PLDLA) having a monomeric composition L- lactide:D,L-lactide of about 70:30; or poly-L-D-lactide having a monomeric composition L-lactide:D-lactide of 70/30 or 50/50; preferably poIy(L-lactide).

4. Plate (1) according to any one of preceding claims wherein the diameter of the holes (2) ranges from 0,1 to 3,0 mm.

5. Plate (1) according to any one of preceding claims wherein its plant-view shape is a square with side dimensions ranging from 30 x 30mm to 200 x 200mm.

6. Plate (1) according to claim 5 wherein the side dimension is 70 x 70 mm.

7. Plate (1) according to any one of preceding claims wherein the thickness (3) thereof is about 0,5 mm.

8. Plate (1) according to claim 6 or 7 wherein the inner radius of curvature is R75 (75 mm).

9. Plate (1) according to any one of preceding claims 6 to 8 wherein the holes (2) have a diameter of about 1 mm and are spaced from each other by 2,5 mm and the distance of said holes (2) from the edge (5) is of about 2,5 mm.

10. Plate (1) according to any one of preceding claims 6 to 9 wherein the corners (6) are rounded with a radius of curvature of about 0,3 mm.