IT201800006816A1 - UNIVERSAL RE-ABSORBABLE PATCH IN PGA FABRIC TO MAKE PROSTHETIC DEVICES FOR VETERINARY USE, IN ASSOCIATION WITH SPECIFIC CONFORMERS - Google Patents

Description

Description of the invention entitled:

"UNIVERSAL REABSORBABLE PATCH IN PGA FABRIC TO MAKE PROSTHETIC DEVICES FOR VETERINARY USE, IN ASSOCIATION WITH SPECIFIC CONFORMATORS"

DESCRIPTION

The present invention refers to a resorbable patch for veterinary use, made of polyglycolic acid (PGA) fiber fabric and conformable, by means of specific conformators, in prosthetic implants for the replacement and / or reconstruction of autologous tissues removed from various animal organs as a result of pathologies and / or trauma.

In particular, the present invention refers to a patch as defined above which is conformable in situ in prosthetic medical devices that can be surgically implanted in the body of the animal in different fields, for example in the orthopedic, gastrointestinal, respiratory, urological and similar fields, to repair , rebuild and / or replace biological structures such as parts of an organ, or to support the local regrowth of said biological structures.

When a portion of tissue of an organ is affected by a serious pathology, such as partial neoplasm, this portion must be removed to prevent the pathology from spreading to the whole organ: the patches are mainly intended to replace the parts of cellular tissue removed from an organ, pending regeneration of autologous tissues.

In the case of patches for human use, if it is intended to replace parts of non-planar tissue such as, for example, portions of the ureter / urethra (tubular patches), or tissues of the renal pelvis and / or pyelo-ureteral joint ( patch in the form of a hollow cone), said patch is industrially made in the shape of the anatomical area for which it is intended and sold already preformed so as to constitute a single prosthetic device ready for use by the surgeon.

In fact, depending on the type of organ to be repaired / reconstructed, the surgeon orders patches with shapes that are closest to the natural ones of various cellular tissues so as to have a series of preformed patches available to be implanted as they are in the operating session in as specific for the various organs.

However, the veterinary use of these preformed patches for human use involves an excessive cost of animal care, prompting in some cases not to have surgery on the animal.

The object of the present invention is to eliminate the drawbacks of the known art, providing a resorbable patch for veterinary use which is economical, easy to make, and has a good initial mechanical strength.

Another object of the present invention is to have such a patch which also has a reduced formation of the fibrotic capsule around it, and which can be applied by the veterinarian in any type of surgical operation without giving rise to infections.

These purposes are achieved by the system in accordance with the invention having the characteristics listed in the attached independent claim 1.

Advantageous embodiments of the invention appear from the dependent claims.

An object of the present invention relates to a system for preparing in situ, during an operating session, a prosthetic device of a given conformation to be implanted in the body of an animal, to replace tissues removed from various organs of animals as a result of pathologies and / or traumas. , in order to reconstruct the autologous tissues of said organs.

Said implantable prosthetic device is not already preformed but is tailor-made by the veterinarian in the operating session, starting from a universal planar patch in standard-sized PGA fabric, which is conformed by the veterinarian into the desired shape by means of of preforms or conformators (sizers) in biocompatible plastic material, e.g. silicone, of various shapes and profiles suitable for simulating various possible tissue areas of resectable organs, where each of said conformators incorporates a dacron mesh or similar material.

The patch will be hooked onto this mesh of the chosen conformator by means of one or more stitches with suture thread, and once the prosthetic device has been modeled, the patch will be separated from its conformator by cutting the stitches at the end of the modeling.

The term "patch" here is intended to identify a substrate different from those called "mesh", "mesh tape" or reinforcement networks which are normally more rigid than the patch and therefore used as supports for sheets or membranes of bioabsorbable materials, as well as different from substrates called “scaffolds” on which culture cells are grown, which are grafted into the animal only after being populated by cells grown in vitro.

Further features of the invention will become clearer from the detailed description that follows, referring to some of its purely exemplary, and therefore non-limiting, embodiments illustrated in the attached drawings, in which:

Figure 1 is a perspective view of a planar patch in PGA fabric according to the invention;

Figure 2 is a simplified sectional view of a hemisphere-shaped conformator according to the invention;

Figure 3 is a perspective view of a bladder in the enlargement phase by inserting a prosthetic device according to the invention;

Figure 4 is a front view of the prosthetic device in the form of a cone according to the invention.

With reference to the Figures, a prosthetic device according to the invention is described, indicated as a whole with the reference number 100, for use in the replacement and repair of damaged cellular tissues that have been removed from one or more organs.

The prosthetic device 100 is made starting from a planar patch 1 in PGA fabric (Fig. 1) which is wrapped around a conformator 20 and fixed to it by stitches with suture thread.

Said conformator 20 can have any shape, for example of a hemisphere (fig. 2) in the event that the prosthetic device 100 is intended for the enlargement of an atrophied bladder 300 (fig. 3).

In the event that the device 100 is intended for the replacement and reconstruction (remodeling of pyeloplasty) of the tissues that form the renal pelvis (shape roughly similar to a funnel), the patch 1 will be wrapped around a cone-shaped conformator (not visible in figure 4) so as to be able to obtain a prosthetic device of the shape as illustrated in fig. 4.

Similarly, the patch 1 will be wrapped around a tube-shaped conformator if the prosthetic device 100 is intended for the replacement and / or reconstruction of ureter and / or urethra tracts.

Thanks to the conformators 20, designed with suitable profiles to simulate the various possible tissue areas to be removed, the aforementioned patch 1 is shaped by the veterinarian in the shape of the tissue area (biological structure) to be reconstructed and / or repaired and / or replaced, such as for example tissues (even soft) of parts of organs of the animal body, so as to obtain directly in situ a prosthetic device ready to be implanted and having any shape suitable for occupying the removed area.

In practice, before performing the resection of the tissue, or just performed, the veterinarian proceeds to shape the planar patch 1 by wrapping it on the conformator 20 which has been selected based on the shape of the removed area in which the prosthetic device 100 will then be implanted.

Once the patch 1 has been shaped, the conformator 20 is removed, cutting the sutures that join it to the patch 1, and the so shaped patch, in the chosen shape, is grafted in the point where the cellular tissue has been removed .

The implantable prosthetic devices 100 which are obtained from the combined use of the patch 1 and the chosen conformator 20 can therefore be in the form of tubes, spheres, tampons, scaffolds and the like, depending on the organ or part of the organ on which they will be implanted. and the purpose of the plant.

These prosthetic devices 100 are inserted as such in the animal without being previously covered (completely or partially) by a culture of stem cells of the diseased organ previously cultured in vitro; moreover, these prosthetic devices 100 do not require any surface treatment to favor the engraftment of growing cell tissues.

The prosthetic device 100 according to the invention can then be implanted in the animal body according to methods known in the art, for example by suturing this device on the target organ or around the perimeter of the area removed from said organ.

In particular, the object of the present invention is a system or kit which includes

(A) a plurality of planar patches 1 made of PGA fabric in at least three different sizes, generally with a rectangular or square shape, preferably 5 cm x 5 cm, 5 cm x 10 cm, 10 cm x 10 cm;

(B) a plurality of conformators 20 (sizers) in silicone reinforced with Dacron mesh, each of said conformators 20 having a specific shape which reproduces the conformation of a specific tissue area of an organ to be reconstructed.

As mentioned, the various conformators 20 present in the kit according to the invention allow the patch 1, once it has been wrapped and fixed on said conformator 20, to assume the conformation of the removed tissue area, for example cone in the case of a renal pelvis, or cylinder, triangle, rectangle, rhombus, or in the most disparate shapes and dimensions.

The conformators 20 are made of silicone and are obtained by molding or dipping, in various standard shapes, such as for example cylinders, cones, rods, wide and narrow flat bars, circles, and so on, in different sizes that cover all needs,

It is also possible to provide a kit of parts according to the invention in which there are 20 conformators made with shapes expressly requested by the veterinarian (custom made).

In order to keep the patch 1 still on the conformator 20 during manipulation, it is provided to fix said patch 1 to said conformator 20 by means of stitches with suture thread which connect the fabric of the patch with the meshes of the Dacron mesh, so as to allow the patch to remain stationary during its modeling.

The planar patch 1 in PGA according to the invention is in the form of a fabric having a fairly reduced thickness, generally around 1 mm.

Said PGA fabric of said patch 1 can be made with a multifilament yarn, or with ultralight monofilament, both deriving from PGA fibers (polyglycolide or polyglycolic acid), preferably homopolymer.

The fabric of the patch 1 of the present invention can be made in various ways giving origin to a knit fabric, a woven fabric, or a nonwoven fabric.

It is preferable to use a knit fabric, in particular warp knit, as it has a more wrinkled surface than the other processes mentioned above.

In one embodiment, the fabric of patch 1 is derived from a PGA monofilament having a linear density (denier) preferably between 120 and 160 denier, where the deniers here refer to the diameter of the monofilament. In this case, the resulting fabric preferably has a denier (also defined as "linear mass density") or a weight of between 240 and 320 deniers. The term denier, D, indicates the weight of the fabric, where 1D corresponds to 9,000 meters of yarn weighing 9,000g (P (g) / L (9,000m)).

When the fabric of patch 1 is made with a multi-filament yarn of PGA fibers, that yarn is approximately 50-200 denier in size.

In another embodiment according to the present invention, the fabric of the patch 1 is made of 75 denier / 30 filament PGA multi-filament yarn (parallel to each other) and is warp knitted. This construction allows the patch 1 to have greater rigidity compared to processing with mono-filament.

The warp knitting process is such that it does not result in a woven fabric or a nonwoven, nor a "felt-like material".

In this case, the texture of the warp knit fabric of patch 1 is such that the interstitial space is less than 200 microns, preferably around 160 microns, corresponding to an average area of the holes equal to about 0.02 mm <2>. This guarantees an impermeability to body fluids.

The warp knitting process is carried out on a warp knitting machine where the yarns are parallel warps and knitted at the same time, with a density preferably of 30 needles / inch, where the yarns are parallel warps and knitted at the same time. , preferably with a processing scheme of the type

Wales Per Inch (WPI) 29-30

Courses Per Inch (CPI) 62-68

With this processing scheme and with the preferred yarn reported above, a fabric with the following characteristics is obtained:

Average area (mm <2>) 0.020

Effective diameter (microns) 140-180

Porosity 70-80%

Surface density (mg / cm <2>) 16-18

The PGA has a degradation time ranging from 4-6 months up to 12 months, but it begins to lose its mechanical strength already after 4 weeks and is completely lost in the fifth month.

The PGA fibers used to make the fabric of this patch are very rigid and are characterized by a high tensile modulus value of 7 GPa and a minimum tensile strength of at least 4.5 grams / denier. Thanks to these properties, the fabric patch obtained with the use of said PGA fibers has a sufficient mechanical consistency and rigidity despite being a flexible and biodegradable fabric. This way the fabric can keep its shape.

It is also possible to use as patch 1 of the present invention PGA fabrics as defined above but also having one or both textured surfaces.

Texturing makes the fabric rough on the surface and is preferable when it is necessary to give patch 1 a certain impermeability to fluids and / or further improve the non-adherence of the patch to the fibrotic capsule: in fact it is presumed that the texturing will cover the micro- holes that exist between the meshes of the fabric.

Texturing of the fabric can be achieved in various ways: by using a superficially rough monofilament obtained according to the methods known in the art (for example, those to obtain texturized PET filament fabrics); or by selecting the diameter of the monofilament and the knit or weft and warp processing such as to result in a fabric with a rough and not smooth surface; or by means of heat-setting treatment of the fabric to obtain reliefs in the fibers giving greater volume to the filament; or by the combination of one or more of said methods.

Texturing by heat-setting treatment is preferred.

Regardless of the texturization or not, the starting planar patch 1 can also be equipped with one or more reinforcement strips made with the same type of fabric as the patch, which are placed on at least one of its surfaces.

It should be noted that the internal and external surfaces of said patch 1 to be wrapped around the conformator 20 are devoid of seeding of culture cells and in this condition the patch is shaped on the conformator 20 by the veterinarian during the operation, in the most suitable shape and size. to the type of intervention that is approached to perform, with the sole aid of a needle, suture thread, scalpel and scissors.

In the operating session, the surgeon removes the area of tissue affected by the neoplasm and then applies the shaped patch detached from the conformator 20 to the removed area, connecting the perimeter of the shaped patch to the edge of the removed area.

The preparation of patch 1 takes place in a controlled environment or controlled contamination, in a clean room. After processing, the three planar patches 1 of different sizes are placed in a double closed blister with a Tyvek sheet to avoid contamination, and this blister is then sent to a sterilization cycle based on ETO (ethylene oxide).

The vet will then be provided with a kit comprising

- a series of planar patches 1 in PGA tissue as defined above, - a series of conformators 20

- thread, needle, scissors, scalpel

to make prosthetic devices for veterinary use.

In practice, the present patch 1, once conformed on the selected conformator 20 and detached from it, is implanted without any surface coating with culture cells, since it has proved to be able to act as a scaffold after its insertion, thus allowing to grow on of it only autologous cells, generated by the tissue reconstruction process of the animal, without requiring any surface treatment to favor the engraftment of the growing tissues.

Numerous variations and detailed modifications can be made to the present embodiments of the invention, within the reach of a person skilled in the art, however falling within the scope of the invention expressed by the attached claims.

Claims (9)

CLAIMS 1. In situ construction system or kit for use in the construction, during an operating session, of a veterinary prosthetic device (100) made of resorbable textile tissue, to be implanted in an animal to replace and / or repair removed cellular tissue from organs that can be resected following pathologies and / or trauma, said system comprising - a universal planar patch (1) in PGA fabric, of given standard dimensions, - a plurality of preforms / conformers (20) (sizers) of various shapes and profiles suitable for assuming the various forms of possible tissue areas of said resectionable organs, each of said conformators (20) being made of biocompatible plastic material and incorporating a mesh in dacron or similar material, said patch (1) being intended to be shaped in situ by a veterinarian in the shape of the tissue removed by means of wrapping over a selected conformator (20) of said kit, subsequent fixing with one or more stitches with suture thread to said Dacron mesh of said selected conformator (20), and final cutting of said sutures at the end of the modeling of said patch (1) to obtain said veterinary prosthetic device (100). 2. System or kit according to claim 1, wherein said conformators (20) are in the form of tubes, spheres, buffer, scaffold, cone, cylinder, triangle, rectangle, rhombus, or in the more shapes and sizes disparate, for example rods, wide and narrow flat bars, circles. System or kit of parts according to claim 1 or 2, wherein said patch (1) is present in at least three different sizes, generally with a rectangular or square shape, preferably with dimensions 5 cm x 5 cm, 5 cm x 10 cm, 10 cm x 10 cm. 4. System or kit according to any one of the preceding claims, wherein the thickness of said planar patch (1) is around 1 mm. 5. System or kit according to any one of the preceding claims, wherein the fabric of said patch (1) is textured. 6. System or kit according to any one of the preceding claims, wherein the fabric of said patch (1) is made with a mono-filament having a linear density between 120 and 160 deniers. System or kit according to any one of the preceding claims 1 to 5, wherein the fabric of said patch (1) is made with a 75 denier / 30 filament multifilament yarn. 8. System or kit according to claim 7, wherein the fabric of said patch (1) is a warp knitted. System or kit according to any one of the preceding claims, wherein the biocompatible plastic material of said conformators (20) (sizer) is silicone.