FR2710269A1 - Implantable device for the treatment of edemas. - Google Patents

Abstract

Device (1) implantable in any living human or animal organism, intended to evacuate any liquid from an edematous collection comprising at least one drainage tube (6) of which one end (6a) called upstream is intended to be implanted in the serous cavity in overpressure and of which another end (6b) called downstream is intended to be implanted in an evacuation zone, said tube having at least in part sufficient flexibility to adapt to the shape of the part in which it is implanted, and being made of at least one biocompatible material, characterized in that the tube has over most of its length between its upstream end (6a) and its downstream end (6b), and in particular in the part intended to be in connection with the evacuation zone, a lateral permeability allowing diffusion of almost all of the liquid taken by its upstream end (6a), from the inside to the outside and by the wall of said tube, but opposing a migratio n cell from the outside to the inside of said tube.

Description

IMPLANTABLE DEVICE FOR THE TREATMENT OF OEDEMAS
The present invention relates to devices or other systems, implantable in humans or animals for treating edematous collections.

 The description below relates more particularly to devices implantable in the eye, both inside and outside the eyeball, making it possible to treat glaucoma, without, however, the scope of the invention be limited. Indeed, the device of the invention applies to the treatment of any edematous collection of the human and animal body such as cerebral, renal edema and hydrocephalus ...

 Glaucoma is an eye disease, which can take acute or particularly severe forms, to the point of causing partial or total blindness in the patient. This disease is generally characterized by hypertonia of the eyeball, i.e. an increase in intraocular pressure, which increases the hardness of the globe and causes compression of the optic nerve, with a decrease in visual acuity.

 In ophthalmology, glaucoma is most often treated by trabeculectomy. This operative technique consists in incising the corneoscleral trabeculum, to create a valve evacuating the aqueous humor in overpressure towards the space under conjunctival.

But to alleviate healing phenomena, it can be associated with the introduction of a biocompatible drainage tube with the eye, allowing the excess aqueous humor to be removed from the anterior ocular chamber.

 To this end, the upstream end of the drainage tube penetrates and is maintained in the anterior chamber, while the other downstream end is implanted first under the scleral flap, then under the conjunctiva, where the aqueous humor is evacuated , to be diffused and absorbed by the surrounding tissues. The drainage tube has at least in part sufficient flexibility to adapt to the shape or local contour of the sclera.

 Such a technique has shown its limits, in the sense that the drainage tube can be colonized by cell proliferation or fibrosis, to the point of gradually closing off, in particular at its downstream end. Under these conditions, glaucoma reappears gradually and requires a new intervention.

 The present invention therefore relates to an implantable device comprising a drainage tube, overcoming the drawbacks of conventional trabeculectomies, by associating therewith the implantation of non-obturable drains. More specifically, the subject of the invention is a device making it possible to diffuse the bodily fluid to be evacuated such as the aqueous humor, while ensuring that it cannot be blocked for the entire duration of its implantation by cell colonies.

 In accordance with the invention, the drainage tube or tubes each have, over the major part of their length between the upstream end and the downstream end, and in particular in their part in contact with the discharge zone, a permeability lateral, making it possible to diffuse almost all of the liquid to be evacuated withdrawn by the upstream end, from the inside to the outside and through the wall of said tube, but opposing cell migration from the outside to the inside said tube.

 According to the invention, a drainage tube then behaves as a lateral diffuser of the aqueous humor, and this in a particularly simple manner.

The present invention also presents the following methods of execution
- according to a first embodiment, the tube of
drainage includes, at least in its part in contact
with the evacuation zone, a multiplicity of
porosities with micro-perforations passing through its wall
right through, and distributed throughout its surface
lateral - according to another embodiment, the material of the
drainage tube is continuous, i.e. not
perforated, but semi-permeable, at least from the inside
outwards, thus allowing diffusion
continues in the same direction, from the aqueous humor, by
simple permeation; preferably, each tube of
drainage is a hollow, porous fiber, especially
having a diameter between 0.3 and 1.2 mm, and a
wall thickness of more than 50 ssm - the device according to the invention may include one or more
several drainage tubes, independent of each other
others; in the latter case, the drainage tubes
can be linked or held together
by a flat fastening means, for example by
a matrix type link encompassing or gluing them
biocompatible (especially polyurethane), and
downstream ends of the tubes are spread out in the area
outlet - preferably the downstream end of the tube
drainage is open - the material of the drainage tube is preferably
hydrophilic, but can be chosen from products
following flexible, namely silicone, polymethacrylate
methyl (abbreviated PMMA), and
polyvinyldifluoroethylene (PVDF), any hydrogel
is ; preferably the drainage tube is a
hydrophilic hollow fiber and in particular a hollow fiber
derived from cellulosic products, a hollow fiber made of
ethylene / vinyl alcohol, polymethyl material
methacrylate, simple polyacrylonitrile or coupled to
sodium methallyl sulfonate, polysulfone and any other
combination of materials to achieve a
porous tubule such as those already used for
artificial kidneys; the material of the drainage tube
can also be chosen from rigid products
like a porous ceramic and in particular of
simple alumina, zirconia-alumina and
tetragonal zirconia; all of these materials
flexible or rigid having benefited from any type of
surface treatment
- for the drainage tube (s) made, consisting
each in a porous hydrophilic hollow fiber, the
porosity is preferably between 10 and
95%.

 Can be used to obtain a drainage tube according to the present invention, any biocompatible polymeric substance, as used to produce any intraocular lens capable of being implanted on the optical axis in the corneal thickness, in the anterior chamber of the eye, between the iris and the natural lens (resting against the latter), or in the lens sac in place of the natural lens, or in the vitreous compartment further back, and capable of correcting any form of optical anomaly (aphakia, high myopia, hyperopia, astigmatism, even presbyopia, and magnifying system for ocular degeneration).

In general, the materials selected must have the following characteristics or properties: - preferably be micro-porous, both to simplify the
realization of the tube (s), only to avoid any
invasion by cell proliferation even
late - be neither biodegradable nor absorbable, to allow
permanent and long-lasting diffusion of the liquid to be evacuated - be neither reactogenic nor irritating to favor
no local fibrosis reaction, hindering
medium-term effectiveness of the device - of course being biocompatible, i.e. well tolerated
by the human or animal body, without any form of
local or general toxicity - have a particularly smooth surface, i.e.
show no major roughness or irregularity by
an observation with an electron microscope for example.

 Hydrogels are preferred materials for obtaining the tube or tubes belonging to a device according to the invention.

 The hydrogels or "gels containing water", are synthetic polymers absorbing water, of soft but firm consistency induced by their hydrophilicity and their insolubility in water. These hydrogels are obtained by copolymerization of monomers having water-solubilizing groups, for example hydroxile, with other monomers, for example ethylene dimethacrylate. These hydrogels are widely used in ophtamology, for example for corneal dressings.

 For the application according to the invention, namely obtaining tubes or tubules, the hydrogels have proved to be well suited, since their hydrophilicity makes it possible to absorb water, while opposing a migration of cells and large molecules (PM greater than 40000 Dalton). Furthermore, they have good oxygen permeability, are optically transparent, and have been found to be mechanically durable.

 As hydrogel, acrylonitrile / sodium methallyl sulfonate is preferred as having, in particular, a high permeability towards liquids, capable of ensuring a significant filtration in glaucoma.

Its biocompatibility is excellent, since in particular it is the most hemo-compatible of the high flux fibers known for artificial kidney.

As an example of such a material, reference will be made to the commercial reference AN69 sold by the
French company HOSPAL.

With this latter material, comprising by weight 30% of non-crosslinked polymers and 70% of water, according to the invention, tubes and tubes with an outside diameter of 340 microns, an inside diameter of 240 microns were obtained and used, and by Consequently, a wall 50 microns thick. These tubes are glycerinated before their use, have a high permeability, for example of the order of 60 ml / h / m2 / mm of Hg, thanks to a pore diameter of less than 100
The surface condition of these hydrogel fibers, already satisfactory at the time of their obtaining, can be further improved by an appropriate surface treatment, for example with treatment at room temperature, in one or more stages, with a long alcohol. aliphatic chain with sequences at different temperatures.

The present invention is now described with reference to the accompanying drawings, in which - Figure 1 shows an anatomical sectional view of a
eye and scleral flap, in relation to which a
device according to the invention is installed - Figures 2, 3, 4 show, in correspondence with
FIG. 1, the eyeball with the scleral flap,
under which a device according to the invention is
implanted - Figure 5 shows an enlarged view, and with
partial removal, a drainage tube forming part
of the device shown in Figures 1 and 2, the pores
being generally invisible to the naked eye.

 Once implanted in the eye and the ocular cavity 3, the device 1 according to the invention makes it possible to evacuate the aqueous humor from the anterior ocular chamber 4 towards the sclera 5. This device here comprises a plurality of drainage tubes 6 , whose upstream or anterior end 6a is implanted in the anterior chamber 4 and whose other downstream or posterior end 6b is implanted under the conjunctiva beyond the scleral flap 8. Each tube is made of a material biocompatible with the eye, in particular in a hydrophilic material capable of being wetted by the aqueous humor, for example hydrogel, and at the same time has sufficient flexibility to adapt to the shape of the sclera 5 and the eyeball. As shown in Figures 1 and 5 together, each tube 6 comprises, at least in its sclerotic part 6c, that is to say in its part disposed after implantation under the scleral flap 8, and in the anterior chamber 4, a porosity or a multiplicity of micro-perforations 6d passing through its wall right through, and distributed throughout its lateral surface. The porous tubes have openings smaller than one micron, to avoid any cellular invasion.

 As shown in FIG. 3, the drainage tube or tubes are implanted in the eye, after cutting a scleral flap 8, which is then replaced by sewing according to FIG. 3, the corresponding surgical act being described below. after.

 As already indicated, each of the tubes 6 can be replaced by a semi-permeable hollow fiber, such as those used in renal dialysis devices, that is to say made of a semi-permeable material, for example a micro-porous polymer, such as hollow fibers or hydrogels.

 An embodiment of the present invention is now described, with one or more tubes each having micro-perforations, or a microporosity.

 A drainage tube according to the invention is preferably delivered sterile ready for use and is implanted in a few minutes, under a microscope, during the intervention.

 The drainage tube is then cut obliquely at its two ends to allow, in the anterior chamber, a sampling zone at its upstream end of the aqueous humor, which is wider, and to more easily avoid any endothelial contact, by suitable rotation. to the tube. At its downstream end, the cut is identical, both so that the tube can, if necessary, be turned over at the time of implantation, as to allow posterior contact as smooth and harmonious as possible.

The sterilization of the perforated drainage tube can be carried out
1) either directly from a tube delivered sterile in
start of intervention,
2) either after rinsing the tube in an ultrasonic tank,
with an antiseptic and biocompatible product
this usually takes 48 hours,
but can be replaced by one of the procedures
applicable to silicone,
3) either after exposure to oxide vapors
ethylene or aldylene (trade name).

 The drainage tube is put in place during a simple trabeculectomy or trepanotrabulectomy performed with 1.7 mm Elliot drill bit, so that the drainage tube (0.7 mm) can be easily inserted diameter or less if three fibers of acrylonitrile or derivative are used), in a slightly larger rounded orifice. The drainage tube is then slid under the conjunctiva in a radial fashion, towards the equator of the globe which it must exceed behind.

The drainage tube can be fixed under the scleral flap, either by a separate point with a 10/0 prolene wire (0.2) by plating the bridge into the sclera and making a "dead turn" around the tube , or simply by closing the scleral flap, even if it has produced a passage strap for the tubule further on the ocular shell. Before tightening any possible point, it is important to ensure, to better protect the corneal endothelium, that
1) the length that emerges in the anterior chamber
or about 2 mm,
2) the oblique section of the upstream end or
anterior of the tube is turned upwards,
that is, the space between the endothelium and the
drainage tube goes up towards the pupil, from
made of the oblique section of the upstream end.

 Conjunctival closure is then practiced in a completely classic way, according to the surgeon's habit, knowing that an opening at a distance from the limbus seems more suitable. Thus, the implantation of an efficient drainage device represented only a simple and easy complement to add to a traditional surgical protocol: "trabeculectomy".

 This same type of drainage device can be introduced in a comparable manner into the space where the cerebrospinal fluid circulates, possibly in overpressure towards the neighboring connective tissue.

Claims (9)

 1. Device (1) implantable in any living human or animal organism, intended to evacuate any liquid from an edematous collection comprising at least one drainage tube (6), one end (6a) of which is called upstream and is intended to be implanted in the serous cavity in overpressure and of which another end (6b) called downstream is intended to be implanted in an evacuation zone, said tube having at least partly sufficient flexibility to adapt to the shape of the part in which it is implanted, and being made of at least one biocompatible material, characterized in that the tube has over most of its length between its upstream end (6a) and its downstream end (6b), and in particular in the part intended to be in relation to the discharge zone, a lateral permeability allowing diffusion of almost all the liquid withdrawn by its upstream end (6a), from the inside to the outside and by the wall of said tube, but opposing cell migration from the outside to the inside of said tube.  2. Device according to claim 1, characterized in that it is intended to evacuate the aqueous humor from the anterior ocular chamber (4) towards the sclera (5) and that it comprises at least one tube (6) of which l end (6a) upstream is intended to be implanted in the anterior chamber (4) of the eye and the other end (6b) downstream is intended to be implanted under the conjunctiva beyond the scleral flap (8).  3. Device according to claim 1 or 2, characterized in that the tube (6) comprises a multiplicity of micro-perforations (6d) or microporosities passing through its wall right through, and distributed throughout its lateral surface.  4. Device according to claim 1 or 2, characterized in that the material of the drainage tube (6) is continuous but semi-permeable, at least from the inside to the outside, and allows continuous diffusion in the same direction , liquid to drain.  5. Device according to claim 1 or 2, characterized in that it comprises a plurality of drainage tubes (6), independent of each other, or connected to each other by means of fastening flat.  6. Device according to claim 1 or 2, characterized in that the downstream end (6b) of the drainage tube (6) is open.  7. Device according to claim 1 or 2, characterized in that the material of the drainage tube (6) is preferably hydrophilic, but can be chosen from silicone, polymethyl methacrylate, polyninyldifluoroethylene, and hydrogels, derived products cellulosic products, ethylene / vinyl alcohol, polymethyl methacrylate, and preferably polyacrylonitrile simple or coupled to sodium methallyl-sulfonate, polysulfone and any other combination making it possible to produce a porous tubule, or among rigid products such as a porous ceramic and in particular a simple alumina, a zirconia-alumina and a tetragonal zirconia.  8. Device according to claim 1, characterized in that the drainage tube is a porous hollow fiber, in particular whose porosity is between 10 and 95%.  9. Device according to claim 1, characterized in that the drainage tube is a hollow fiber, in particular having a diameter between 0.3 and 1.8 mm, with a wall thickness of more than 50 mm.