RU2309781C1 - Draining tube usable in antigalaucoma operations - Google Patents

Abstract

FIELD: medical engineering.

SUBSTANCE: device is manufactured from newly synthesized polymer digel being transparent polymer produced as a result of monomers and oligomers mixture photopolymerization.

EFFECT: reliable fixability of the digel explantodrainage without additional suturing; favorable conditions for intraocular fluid circulation; stimulated intraocular fluid discharge.

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Description

The invention relates to medicine, and more specifically to ophthalmology, and is intended for the surgical treatment of refractory glaucoma.

A known model of drainage for anti-glaucoma operations, made in the form of a tube of cylindrical shape with porous walls, described in US patent No. 5968058. This type of drainage is used for secondary glaucoma and is implanted at one end into the anterior chamber of the eye, and the other, the outer end, under the conjunctiva.

Nevertheless, this model is not without certain drawbacks. In particular, the proposed design of the drainage does not exclude its dislocation into the anterior chamber of the eye at different times after implantation, which can lead to trauma to the iris or endothelium of the cornea and cause recurrent hyphema, iridocyclitis, and epithelial-endothelial dystrophy of the cornea. In addition, insufficient elasticity, stiffness of the cylindrical drainage can lead to excessive expansion of the puncture of the sclerotic corneal tissue at the injection site of the drainage into the anterior chamber during eyeball movements and, in turn, lead to the development of a shallow anterior chamber syndrome, and then to its complete emptying, which is fraught with detachment of the choroid, prolonged hypotension and macular edema. Drainage of the proposed form and with the proposed method of fixation can also shift under the conjunctiva, which leads to the loss of its drainage role. In addition, the drainage lumen can become clogged with blood or hemose fibrin, which prevents the drainage from performing its function and reduces the hypotensive effect of antiglaucoma surgery. In addition, the implantation of this drainage model promotes the filtration of intraocular fluid mainly under the conjunctiva, which is insufficient for the treatment of intractable forms of glaucoma. Also, the implantation of a cylindrical drainage requires additional suture fixation, which requires additional time and a certain qualification of the surgeon. In addition, the material from which this model is made does not prevent the formation of a connective tissue capsule around, and, thus, a rapid obliteration of the formed drainage paths occurs and the drainage loses its functions.

The aim of the invention is to create a new model of explant drainage from a new polymer material for the surgical treatment of glaucoma, especially its severe, refractory forms, where a minimal reaction to the implant from the surrounding tissues is required, minimal trauma to the surrounding tissues in combination with a simple implant drainage implant without additional suture fixation in order to obtain a persistent hypotensive effect as a result of stimulating all possible pathways of the outflow of intraocular fluid (HPW).

The technical result of the invention is perforated explant drainage from a new polymeric material - a digel, which, due to its composition, shape and structure, allows for a long time to maintain the intrascleral cavity formed during anti-glaucoma surgery, to achieve a high level of biocompatibility, which allows a long-term reactive presence of the implant in the eye under conditions of minimal intra- and postoperative complications.

The technical result is achieved by the fact that for the manufacture of drainage a new polymer material is synthesized - a digel. The drainage material is a transparent polymer obtained by photopolymerization of a chemical composition consisting of the following substances taken in certain ratios: ethylene glycol monomethacrylic ester (10-40 wt.%), Methacrylic acid (2.0-8.0 wt.%) , 2,2-dimethoxy-2-phenylacetophenone (0.1-0.7 wt.%), 2,4-ditretbutylorthoquinone (0.001-0.006 wt.%), Oligourethane methacrylate - the rest. After curing the composition, we obtain drainage in the form of a rectangle with rounded corners with a radius of curvature of at least 1 mm and holes located along its area so that the distance from the edges of the rectangle to the peripheral rows of holes is from 0.5 to 1 mm, capable of folding after swelling in water and the restoration of a given shape, with increased strength and elasticity, increased stability in biologically active environments, increased resistance to oxidative processes and adsorption processes elkov on the surface prevents the formation of coarse connective tissue capsule.

The set of minimum values of the ingredients determines the threshold value from the point of view of the minimum below which either the required strength of the product is not achieved, or the polymerization process is incomplete, which leads to acute reactions in the tissues of the eye, as well as a decrease in stability in biologically active environments (chamber moisture of the eye) , resistance to oxidative processes and processes of protein adsorption on the surface.

The maximum values of the ingredients are determined by the fact that, at high values, either excessive rigidity or deterioration of such characteristics as distortion of shape, the appearance of turbidity, etc., is manifested, which leads to trauma to adjacent tissues of the eye.

Example 1. Oligourethane methacrylate (OAA) is obtained by catalytic interaction

Laprol 2102, TU 2226-411-05761784-95 buildings

HO- (CH (CH ₃ ) -CH ₂ ) n-OH, where n = 36;

2,4-toluene diisocyanate (TDI) TU 113-38-95-90, structure

ethylene glycol monomethacrylic ester (MEG) TU 6-01-1240-80 structure

HO- (CH ₂ ) ₂ —O — C (CH ₃ ) = CH ₂ .

Tin dibutyl dilaurate, structure, is added as a catalyst.

(CH ₃ (CH ₂ ) ₃ ) ₂ Sn (CH ₃ (CH ₂ ) ₁₀ COO) ₂ .

As an inhibitor, 2,4-ditretbutylorthoquinone, structures

The consumption rate per 1 kg of the finished product, based on 100% of the content of the main substance for all the starting reagents, is:

laprol 2102-766.77 g;

TDI - 133.53 g;

MEG - 99.67 g;

tin dibutyl dilaurate - 0.027 g;

2,4-ditretbutylorthoquinone - 0.003 g.

The practical expenditure rate is calculated based on the analysis of the determination of OH groups and NCO groups in the initial laprol and TDI, and in the intermediate product, macrodiisocyanate. All raw materials used to obtain OAA oligourethane methacrylate must comply with scientific and technical documentation, the moisture content in laprol should not exceed 0.1%. Additionally, laprol 2102 is dried in a rotary film evaporator at 100 ° C for 3 hours. After that, the content of OH groups is determined according to GOST 25261-82. TDI before synthesis is distilled in a device for vacuum distillation and determine the content of NCO groups according to TU 113-03-413-89.

First, the macrodiisocyanate structure is synthesized

The synthesis is carried out at a ratio of NCO groups in the reaction mixture to the number of OH groups equal to 2: 1, as follows: into a reactor, which is a cylindrical apparatus with a volume of 5-6 l, made of steel grade 12X18H10T, with a lid on which fittings for the refrigerator are located , a reagent loading device and an inert gas inlet (argon) equipped with a stirrer, with a gearbox providing a rotational speed of the stirrer of 60-90 rpm, and a conductive jacket for heating the reaction mixture are loaded sequentially at a temperature of 30-40 ° С prol 2102; freshly distilled TDI; tin dibutyl dilaurate catalyst with the agitator turned on and a dry inert gas stream. The synthesis of macrodiisocyanate is carried out at a temperature of 50-55 ° C until the content of NCO groups in the macrodiisocyanate is equal to 0.5 of the loaded number of NCO groups for about 2 hours, after which a sample is taken and the content of NCO groups is determined. The content of NCO groups is determined according to TU 113-03-413-89. When the content of NCO-groups is more than 0.5, the sample is taken again 1 hour after the first selection. Then, a polymerization inhibitor 2,4-ditretbutylorthoquinone is added to the calculated amount of MEG (NCO: OH = 1: 1). MEG is poured into the reactor with the stirrer operating and the reaction mixture is kept at a temperature of 50-55 ° C until the content of residual NCO groups is not higher than 0.05%. After draining the OAA into the container, the container is sealed and aged for 5 days in a closed warehouse.

Example 1. In a reaction flask equipped with a stirrer, the components are sequentially introduced in the following ratio, g:

oligourethane methacrylate n = 36 78.19 ethylene glycol monomethacrylic ester 13,4 methacrylic acid 7.78 2,2-dimethoxy-2-phenylacetophenone 0.6265 2,4-ditretbutylorthoquinone 0.0035

The resulting mixture was stirred at room temperature for 40 minutes until complete dissolution of 2,2-dimethoxy-2-phenylacetophenone and 2,4-ditretbutylorthoquinone.

Drainage is made in glass molds consisting of two halves, one of which has a pattern, for example, of iron oxide with geometric dimensions that exactly match the drainage (see drawing). A bounding frame of 150 μm thick, for example, from lavsan, is attached to the glass half with a pattern, the composition is evenly distributed over the internal volume of the bounding frame and covered with the upper glass half of the mold. The assembled glass form is transferred to an exposure unit consisting of a light source (a DRT-120 mercury-quartz lamp) and a collimator, and irradiation is carried out for the time necessary to completely reproduce the drainage form indicated in the drawing. When the intensity of the light incident on the surface of the mold, 440 W / m ^{2 the} optimal exposure time is 2 minutes After irradiation, the mold is disassembled, separating one half of the mold from the other and removing the restrictive pad. Further, all operations are performed with a half of the form on which the drainage is formed. Half of the mold with drainage is placed in a development unit consisting of a 200 ml developer cuvette, a developer circulation pump, and a nozzle located in the cuvette lid. The form with drainage is placed in a cuvette, the developer isopropyl alcohol is poured, closed with a lid and the pump is turned on. Duration of manifestation of drainage is 2 minutes. During the development, the non-polymerized part of the photocurable material is removed, which during exposure was located under the UV-opaque portions of the pattern made on the lower half of the mold (see drawing). After development, the drainage is dried in a stream of warm dedusted air for 1 min. Next, the drainage on the half of the mold is transferred to an exposure unit consisting of a source (a mercury-quartz lamp of the DRT-120 brand) and a vacuum pump providing a vacuum of 10 ^-1 mmHg and annealing stage is carried out, which consists in additional irradiation of the drainage. When the intensity of light incident on the surface, 330 W / m ² the irradiation time is 10 minutes After additional exposure, the drainage is separated from the mold. It turns out a drainage capable of folding after swelling in water and restoring a given shape, with increased strength and elasticity, increased stability in biologically active media, increased resistance to oxidative processes and protein adsorption processes on the surface, the characteristics of which are given in the table.

Example 2

The composition is prepared, as in example 1, in the following ratio of components, g:

oligourethane methacrylate n = 36 87,899 ethylene glycol monomethacrylic ester 10.0 methacrylic acid 2.0 2,2-dimethoxy-2-phenylacetophenone 0.1 2,4-ditretbutylorthoquinone 0.001

Make a drainage, as in example 1. The characteristics are shown in the table.

Example 3

The composition is prepared, as in example 1, in the following ratio of components, g:

oligourethane methacrylate n = 36 51,294 ethylene glycol monomethacrylic ester 40,0 methacrylic acid 8.0 2,2-dimethoxy-2-phenylacetophenone 0.7 2,4-ditretbutylorthoquinone 0.006

Make a drainage, as in example 1. The characteristics are shown in the table.

Example 4

The composition is prepared, as in example 1, in the following ratio of components, g:

oligourethane methacrylate n = 36 18.79 ethylene glycol monomethacrylic ester 60.0 methacrylic acid 20,0 2,2-dimethoxy-2-phenylacetophenone 1,2 2,4-ditretbutylorthoquinone 0.01

Make a drainage, as in example 1. The characteristics are shown in the table.

Example 5

The composition is prepared, as in example 1, in the following ratio of components, g:

oligourethane methacrylate n = 36 93.9799 ethylene glycol monomethacrylic ester 5,0 methacrylic acid 1,0 2,2-dimethoxy-2-phenylacetophenone 0.02 2,4-ditretbutylorthoquinone 0.0001

Make a drainage, as in example 1. The characteristics are shown in the table.

The design of the explant drainage from the digel allows you to securely fix it without additional suture fixation and, thus, prevent formidable complications associated with the possible dislocation of implants, in particular, its loss in the anterior chamber or under the conjunctiva. The lack of need for suture fixation avoids such formidable complications as perforation of the ciliary body and hemophthalmus.

The perforated mesh structure of our explant drainage model does not impede the free circulation of the incoming fluid in all directions - under the conjunctiva, into the intrascleral collectors and into the choroid vasculature, and thus stimulates all possible routes of outflow of intraocular fluid in patients with refractory glaucoma.

Perforated digel drainage is implanted intrasclerally. After an incision of the conjunctiva and separation of the superficial scleral flap with an exfoliator for anti-glaucoma operations, an additional intrascleral cavity (pocket) is formed up to dimensions 6.0 × 8.0 mm on all sides at the level of the superficial scleral incision. A perforated drainage is implanted into the formed intrathoracic cavity using 2 microsurgical forceps for tying sutures. If necessary, the drainage is straightened in a pocket with a microsurgical spatula. Additional suture fixation of drainage is not required. Adaptation of the surgical wound is carried out in the traditional way.

The invention is illustrated in the drawing, which schematically shows a front view of the proposed model of drainage for anti-glaucoma operations (1) with numerous holes (2) distributed evenly over the entire surface of the drainage.

The invention is illustrated by the following clinical examples.

Example 1. Patient K., 56 years old. The diagnosis at admission is secondary decompensated phacotopic glaucoma in both eyes, incomplete complicated cataract, lens subluxation. Visual acuity of both eyes - 0.1, does not correct. Intraocular pressure (IOP) of the right eye - 41 mm Hg, IOP of the left eye - 39 mm Hg A history of IOP elevation for 1-1.5 years. Instills antihypertensive drugs (arutimol 0.5% 2-3 times a day). Against the background of drug therapy, IOP of both eyes is uncompensated.

On the right eye, a non-penetrating deep sclerectomy was performed with intrascleral implantation of perforated digel drainage according to the invention. A week later, a similar operation was performed on the left eye. Operations and the postoperative period were uneventful. At discharge, the acuity of both eyes remained unchanged, the IOP of both eyes is -18 mm Hg.

When viewed 6 months after surgery, the IOP remains compensated and amounts to 19-20 mm Hg. Against the background of normalized IOP, operations were performed to replace the subluxated turbid lens with an artificial one. When viewed after 1 year, the acuity of both eyes is 0.5-0.6. IOP of both eyes - 20 mm Hg Ultrasound biomicroscopy data confirm the presence of an extensive intrascleral cavity with clearly visualized drainage. There are also signs of newly formed outflow pathways of the intraocular fluid, in particular uveoscleral.

Example 2. Patient S., 69 years old. Preoperative diagnosis of the right eye - O / Y III associated glaucoma. The left eye is enucleated for terminal painful glaucoma. A history of glaucoma for 10 years. Antiglaucoma operation on the right eye 2 years ago. At the time of admission, hypotensive drugs are instilled, which do not have a satisfactory effect. On admission: visual acuity of the right eye - 1.0 with a narrowed to a tubular field of view. IOP - 36 mmHg

A deep sclerectomy operation was performed with intrascleral implantation of perforated digel drainage according to the invention. The operation and the postoperative period proceeded without complications. At discharge, visual acuity was unchanged, IOP - 16 mm Hg.

When viewed through 3, 6, 12, 24 months after the operation, visual acuity and IOP are stable, the field of view expanded by 5 degrees. from the fixation point. The data of ultrasonic biomicroscopy confirm the safety of the newly formed outflow pathways of the HPW.

Table Example drainage The coefficient of linear expansion after hydration Geometrical dimensions in hydrated
condition, compliance with a given form The optical density of the water extract Surface Adsorption of Proteins Elasticity and bending strength one 1,04 corresponds to 0.005 no elastic, durable 2 1,04 corresponds to 0.004 no elastic, durable 3 1,04 corresponds to 0.005 no elastic, durable four 1.20 more 0.2 there is elastic, breaks when bent 5 1.01 smaller 0.21 there is low elasticity, a trace remains in the bend

Claims (2)

1. Drainage for antiglaucomatous operations, made in the form of a plate with a thickness of 100-200 microns with through holes in an amount of at least 96, characterized in that the drainage is formed with holes of various shapes by photocuring the composition, consisting of a mixture of oligourethane methacrylate structure

n = 36 2,2-dimethoxy-2-phenylacetophenone structure Ph-C (O) -C (CH ₃ ) ₂ -Ph 2,4-ditretbutylorthoquinone structure

ethylene glycol monomethacrylic ester structure HO-CH ₂ —CH ₂ —O — C (O) —C (CH ₃ ) = CH ₂ , methacrylic acid structure HO-C (O) -C (CH ₃ ) = CH ₂ while the above components are taken in the following ratio, wt.%: 2,2-dimethoxy-2-phenylacetophenone 0.1-0.7 2,4-ditretbutylorthoquinone 0.001-0.006 ethylene glycol monomethacrylic ester 10-40 methacrylic acid 2.0-8.0 oligourethane methacrylate rest in the form of a rectangle with rounded corners with a radius of curvature of at least 1 mm and openings located along its area so that the distance from the edges of the rectangle to the peripheral rows of openings is from 0.5 to 1 mm. 2. The drainage for anti-glaucomatous operations according to claim 1, characterized in that the holes are either round in shape with a diameter of 50-300 microns, or square in shape with side lengths from 50 to 350 microns, or triangular in shape with side lengths from 50 to 350 microns, or a rectangular shape with a length of one side from 50 to 200 microns and a length of the other side from 100 to 1000 microns, oriented along or across the longitudinal axis of the drainage.