RU177889U1 - Drainage for the surgical treatment of glaucoma - Google Patents

Abstract

The utility model relates to medicine, more specifically to ophthalmology. A plate-shaped drainage is proposed, having a thickness of 25 to 500 μm, made of a composite porous material in the form of fibers of synthetic polymers impregnated with natural polymers, which form through and longitudinal pores with total porosity more than 85%, with an average fiber diameter of less than 1.0 μm, while the synthetic polymer for forming the fibers is selected from the group: polycaprolactone, polyurethane, lactic acid polymer with or without copolymers, and p The natural polymer for the impregnation of synthetic fibers is selected from the group: collagen, collagen hydrolysis product, chitosan. Technical result: increased drainage porosity and more efficient discharge of intraocular fluid. 5 cp f-ly, 2 Fig.

Description

The utility model relates to medicine, namely to ophthalmology, and can be used for the surgical treatment of glaucoma, especially its refractory form, which is the most intractable nosological form.

Glaucoma is one of the most severe eye diseases, leading to a significant decrease in visual function up to blindness. The special form of glaucoma “refractory” (difficult to cure) combines a wide variety of clinical types, including pseudophakic, aphakic, and also repeatedly and unsuccessfully operated primary glaucoma. These forms of glaucoma have risk factors for excessive scarring in the area of surgical intervention. Surgical treatment is the main treatment for refractory glaucoma. The main reason for reducing the effect of filtering operations is excessive, unregulated scarring in the area of newly created outflow pathways of intraocular fluid, which leads to relapse. In order to reduce cicatricial processes in the area of surgical intervention, various types of drains are used to preserve the formed cavity.

To date, the most widely used are drainages made of polymer materials of medical grade (Krupin T., Am. J. Ophthalmol. - 1980. - Vol. 89. - P. 338-343; Molteno, Austr. J. Ophthalmol. - 1985. - Vol. 13. - N. 4. - P. 329-335).

Known drainage for anti-glaucomatous operations, made in the form of a plate of collagen copolymer, characterized in that it has a rectangular shape with sizes from 4 × 6 mm to 6 × 8 mm and a thickness of 100-200 μm, while at least the entire drainage area is made 96 through holes with a diameter of 100-200 microns (patent RU 28018 U1, 03/10/2003).

The disadvantages of the known drainage are the rapid clogging of the pores in the drainage and the formation of a dense connective tissue capsule around the drainage.

Known drainage for anti-glaucomatous operations, made in the form of a trapezoidal plate made of a porous material with a pore diameter of 0.1 to 40 μm, while a collagen copolymer with a water content of 60-90 wt. % (patent RU 16901 U1, 02.27.2001)

The disadvantages of the known drainage are the rapid clogging of the pores in the drainage and the formation of a dense connective tissue capsule around the drainage.

The closest to the claimed drainage - the prototype is a drainage for the surgical treatment of glaucoma, made in the form of a plate of biocompatible porous material, having first and second ends, and also located between them at least one flat section so as to enable laying of the specified flat section during surgical treatment under a separated scleral flap with the location of the first and second ends outside the scleral bed, while it mainly has a rectangular shape with a length w 3,0-12,0 mm and a height of 1.0-3.5 mm, the drainage thickness of 10-300 microns and biocompatible material selected from the group consisting of synthetic polymers, a microbiologically synthesized materials. A hydrogel based on polyvinyl alcohol or a grafted copolymer containing polyvinyl alcohol and polyethylene glycol was selected as a synthetic polymer. As the microbiologically synthesized material, one of the following materials was used: poly-3-hydroxybutyrate, poly-3-hydroxyvalerate or poly-4-hydroxybutyrate or their copolymers (patent RU 134787 U1, 11.27.2013).

The disadvantages of the known drainage are its insignificant elasticity, which can lead to microtraumatization along the periphery of the implant and, as a result, the intensification of fibrosing processes, which, in turn, is realized in the repeated blockade of the outflow of intraocular fluid, as well as low porosity and the presence of only through pores, providing passive discharge of intraocular fluid in the radial direction, which is specified by the drainage planes.

The objective of the utility model is the development of a new, more advanced drainage design with elasticity, greater porosity and increased functionality.

EFFECT: increased drainage porosity and providing more effective discharge of intraocular fluid based on a pressure gradient and the phenomenon of capillary fluid flow.

The task is achieved by the proposed drainage for the surgical treatment of glaucoma, which is a rectangular plate with a length of 6.0-9.0 mm and a height of 3.0-4.0 mm with a thickness of 25-500 microns, made of a biocompatible composite porous material in the form fibers from synthetic polymers impregnated with biological (natural) polymers, forming in it through and longitudinal pores with a diameter of not more than 100 microns, with an average fiber diameter of less than 1.0 microns.

As a synthetic polymer, one of the following polymers can be used: polycaprolactone or its modifier, polyurethane, a lactic acid polymer with various molecular weights with or without copolymers, an ester, etc. As a natural polymer for the impregnation of synthetic fibers, one of the following polymers: collagen, the product of its hydrolysis, chitosan.

Synthetic polymers form the porous drainage base of fibers with average diameters of less than 1.0 μm and define through and longitudinal pores, while biological polymers - collagen, chitosan and other impregnating synthetic fibers, increase the hydrophilic properties of the drainage and improve its biocompatible properties . The drainage can be of any shape (for example, rectangular, trapezoidal or oval), depending on the clinical situation of its use.

The proposed drainage provides intraocular fluid flow through the formed pores, both in the through and longitudinal directions due to the effect of capillary fluid flow and pressure gradient from the zone of greater pressure in the direction to the smaller.

Drainage can be made using the electrospinning method (T. Stylianopoulos, et al / J. Mech. Behav. Biomed Mater. - 2008, - Vol. 1 - N 4. - P. 326-335), or using 3D printing ( Development of simple 3D printing scaffold for liver tissue engeeniring. James Camp / The University of Texas at Austin, 2002 - pp. 58).

The synthetic polymer in the composite material is preferably 9.0-11.0 mass. %, and the natural polymer is 0.1-4.0 mass. % (relative to the weight of the solvent).

Drainage is used as follows.

After preparation of the surgical field and combined anesthesia, a superficial scleral flap is formed, a deep scleral flap is excised, the outer wall of the Schlemm canal and corneoscleral tissue are removed. Porous drainage is placed in the formed bed, fixing sutures are applied. The linear dimensions and shape of the drainage are selected intraoperatively, depending on the specific clinical situation.

Percent volumetric porosity was calculated by analyzing the optical slices obtained by forming the 3D model of the sample using the Z stack method. (P. M. Larionov et. All, Perfusion properties of scaffolds: A new approach to tissue engineering designs for bone regeneration // Citation: AIP Conference Proceedings 1882, 020042 (2017); doi: 10.1063 / 1.5001621 View online: http: / /dx.doi.Org/10.1063/l.5001621).

In FIG. 1 is a 3D model of a drainage fragment made of polycaprolactone impregnated with collagen. The fiber sizes are less than 1.0 microns, funnel-shaped periodic structures, not more than 100 microns in diameter, porosity 94%. Laser scanning confocal microscopy. × 40 lens, oil immersion.

In FIG. Figure 2 presents a 3D model of a drainage fragment made of polycaprolactone impregnated with gelatin. Fiber sizes are less than 1.0 μm, fibers form periodic funnel-shaped structures, porosity 85%. Laser scanning microscopy. × 40 lens, oil immersion.

The defining differences of the claimed drainage, in comparison with the prototype, are:

- the drainage has a thickness of 25-500 μm and the through and longitudinal pores formed in it with a diameter of not more than 100 μm, which allows to increase the functionality of the latter and provide a more efficient discharge of tissue fluid based on the pressure gradient and the phenomenon of capillary fluid flow, as well as to prevent the process scarring of the outflow of IOP;

- the drainage is made of a composite material in the form of fibers with an average diameter of less than 1.0 μm from synthetic polymers impregnated with biological (natural) polymers, which form through and longitudinal pores in it, which makes it possible to increase its elasticity and porosity.

The utility model is illustrated by the following examples of specific use.

Example 1

Patient X, 77 years old, was admitted to the Novosibirsk branch of the IRTC "Eye Microsurgery" with a diagnosis of the right eye - operated on for open-angle glaucoma, the condition after revascularization of the optic nerve.

On admission: Visual acuity of 0.3, IOP - 35 mm RT. Art.

The operation was performed using rectangular drainage, with a size of 4 × 9 mm, having a thickness of 50 μm, made of polycaprolactone (PCL) fibers impregnated with gelatin (PCL - 11.0 wt.%, Gelatin - 2.0 wt.%), forming in it through and longitudinal pores with an average diameter of 30 microns, with an average fiber diameter of 0.4 microns, the porosity of the drainage is 85%. After a conjunctival incision was made, a scleral surface flap 7 × 5 mm was cut into the scleral bed in the scleral bed to 2 mm deep into the transparent layers of the cornea. The front wall of the Shlemmov canal was removed to the width of the scleral bed with strips of corneoscleral and corneal tissue. A flap was cut out from the middle layers of the sclera according to the size of the scleral bed, which was removed after separation, a composite porous drainage was placed in the formed bed, a suture was placed on the conjunctiva. The patient was discharged on the 5th day.

At discharge, visual acuity was 0.4 without correction, with a correction of 0.7. IOP - 19 mm RT. Art. After 1 month of IOP - 18 mm RT. Art., after 3 months - 22 mm RT. Art., after 6 months - 22 mm RT. Art. There are no complaints about visual impairment.

Example 2

Patient A, 90 years old, was admitted to the Novosibirsk branch of the IRTC "Eye Microsurgery" with a diagnosis of open-angle glaucoma of the right eye, a condition after revascularization of the optic nerve. Operation deep non-penetrating sclerotomy in 2013. Refractory form.

On admission: Visual acuity of 0.2 is not corrected, IOP - 37 mm RT. Art.

The operation was performed using oval-shaped drainage with a length of 6 mm, a height of 3 mm, and a thickness of 250 μm, made of polyurethane fibers (PU) impregnated with natural collagen of animal origin (PU-9.5 wt.%, Collagen - 0 , 1 wt.%), Forming through and longitudinal pores, drainage porosity is 90%. After the incision of the conjunctiva was performed, a superficial scleral flap 6 × 7 mm was cut out in the scleral bed in the scleral bed to 2 mm deep into the transparent layers of the cornea. The front wall of the Shlemmov canal was removed to the width of the scleral bed with strips of corneoscleral and corneal tissue. A flap was cut out from the middle layers of the sclera according to the size of the scleral bed, which was removed after separation, a composite porous drainage was placed in the formed bed, a suture was placed on the conjunctiva. The patient was discharged on day 4.

At discharge, visual acuity was 0.2 without correction, IOP - 19 mm RT. Art. After 1 month of IOP - 17 mm RT. Art., after 3 months - 20 mm RT. Art., after 6 months - 22 mm RT. Art. There are no complaints about visual impairment.

Example 3

Patient R., 64 years old, was admitted to the Novosibirsk branch of the IRTC “Eye Microsurgery” with a diagnosis of primary open-angle glaucoma of the right eye. Operations of deep non-penetrating sclerotomy in 2010, in 2014. Refractory form.

Upon receipt, visual acuity of 0.6 with a correction of 0.9, IOP - 31 mm RT. Art.

An operation was performed on the Schlemmm canal using composite porous drainage made from fibers of a lactic acid polymer (PMA) impregnated with chitosan (PMA - 9.0 wt.%, Chitosan - 4.0 wt.%), Forming through and longitudinal pores with an average diameter of 20 microns, having a trapezoidal shape, with a large base of 4 mm, a smaller base of 2 mm, a height of 6 mm, with a thickness of 500 microns, with an average fiber diameter of 0.980 microns, the drainage porosity is 94%.

After preparation of the surgical field, combined anesthesia, a superficial scleral flap was formed, a deep scleral flap was dissected, the outer and inner walls of the Schlemm's canal and corneoscleral tissue were removed. Prepared drainage was laid in the formed bed with the distal part of the drainage advancing into the projection of sinusoidal structures, which serves to replace or replace the Shlemmov canal.

The patient was discharged on the 3rd day. At discharge, visual acuity of 0.7, with a correction of 1.0; IOP - 16 mm RT. Art. A month later, IOP - 18 mm RT. Art., after 3 months - 19 mm RT. Art., after 6 months - 18 mm. Hg. Art. There are no complaints about visual impairment.

The proposed drainage has a porosity of more than 85%, provides a more effective discharge of intraocular fluid based on the pressure gradient and the phenomenon of capillary fluid flow. At the same time, it retains intrascleral cavities formed during antiglaucomatous surgery for a long time, ensures its long-term presence in the eye under conditions of minimal intra- and postoperative complications

Claims (6)

1. Drainage for the surgical treatment of glaucoma, made in the form of a plate of a biocompatible polymer porous material, characterized in that the drainage is made of a composite material in the form of fibers of synthetic polymers impregnated with natural polymers, forming in it through and longitudinal pores with a diameter of not more than 100 microns while the thickness of the drainage is 25-500 microns, and the average fiber diameter is less than 1.0 microns. 2. Drainage according to claim 1, characterized in that the synthetic polymer for forming the fibers is selected from the group: polycaprolactone, polyurethane, lactic acid polymer with or without copolymer. 3. Drainage according to claim 2, characterized in that the synthetic polymer in the composite material is from 9.0 to 11.0 mass fractions. 4. Drainage according to claim 1, characterized in that the natural polymer for impregnating synthetic fibers is selected from the group: collagen, the product of its hydrolysis, chitosan. 5. Drainage according to claim 4, characterized in that the natural polymer in the composite material is from 0.1 to 4.0 mass fractions. 6. Drainage according to claim 1, characterized in that it is characterized by porosity ranging from 85 to 94%.

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