RU217934U1 - Device for implantation of a polymeric glaucoma shunt - Google Patents

Abstract

The utility model relates to the field of medicine, namely to microsurgical instruments used in ophthalmic surgery for introducing glaucoma shunts into the eye during ophthalmic operations. The device comprises a body, in the working part of which there is a hollow tip with an oblique cut corresponding to the inclination of the shunt support elements; a needle with a diameter corresponding to the inner diameter of the shunt, placed inside the tip and connected to the rod, which is made with the possibility of reciprocating movement inside the housing. The device ensures the accuracy of insertion and positioning of the shunt in the operating area and excludes the possibility of its displacement during the insertion; reduces the risk of iatrogenic complications during implantation of a glaucoma shunt, the risk of damage and destruction of the shunt during implantation, reduces the number of repeated operations, and as a result, contributes to the stabilization of the glaucoma process, preserves visual functions in patients with glaucoma.

Description

The utility model relates to the field of medicine, namely to microsurgical instruments used in ophthalmic surgery for inserting glaucoma shunts into the eye cavity during ophthalmic operations.

Glaucoma is a large group of diseases united by a symptom complex: a violation of the hydrodynamics of the eye, accompanied by a change in ophthalmotonus; glaucomatous optic neuropathy and typical visual impairment. Glaucoma is the leading cause of irreversible blindness. According to the WHO, about 3 million people have lost their sight due to primary open-angle glaucoma, and every year about 2 million people in the world are diagnosed with this disease for the first time, which indicates a steady increase in the incidence. A significant part of patients with glaucoma (more than 50%) do not feel subjective symptoms in the early stages of the disease. The progression of glaucomatous optic neuropathy due to the ineffectiveness of the maximum possible therapy is an indication for surgical treatment of the disease.

Traditional methods of glaucoma surgery (Krasnov M.L., 1987; Chen T.C., 1997) attract ophthalmic surgeons with their relative ease of implementation and a stable decrease in intraocular pressure in the postoperative period, but scarring of the postoperative filtration zone often leads to relapses of an increase in intraocular pressure, followed by progression of glaucoma and loss of vision, especially with repeated surgical interventions

A promising direction in glaucoma surgery is the implantation of shunts, which provide more stable and long-term normotension, but there is a need to develop a device for the delivery, i.e. implantation, of glaucoma shunts. Today, devices for implanting polymeric shunts are presented in a few literary sources, and in our opinion, they have a number of significant drawbacks. One of the ways to reduce the risk of postoperative complications during glaucoma shunt implantation is to further improve the methods of performing these interventions by developing more advanced and efficient devices for implanting glaucoma shunts.

A device is known for introducing a glaucoma shunt into the cavity of the eyeball, namely into the anterior chamber (patent RU 2648229). The device includes a housing with an internal cavity and a groove for a sliding element extending from the outer surface of this housing into the specified cavity; a needle with a lumen; a plunger configured to move within said lumen; a drive component containing a cylindrical element connected to the needle through a needle slot and the plunger through a plunger slot to ensure their movement along the longitudinal axis of the device during rotation of this component, while the drive component additionally includes a slot for the sliding element, longitudinally overlapping the slot for needles and groove for the plunger; and a sliding element connected to and slidable along the body, the sliding element being connected to the drive component via the sliding element slot so that movement of the sliding element along the axis rotates the drive component inside the body and moves the needle and plunger along said axis .

When using the known device, the shunt is located in the lumen of the needle and is not fixed, therefore, during the extension from the needle during implantation, the device does not allow controlling the depth of the shunt insertion, which reduces the efficiency of the operation. In the process of shunt implantation, when it is advanced inside the needle, jamming in the lumen of the needle is possible, which can lead to damage to the shunt, which will require repeated manipulations and greatly increase the duration of the operation, which means that the risk of associated complications will also increase. The method of using the device involves the introduction of an injector into the anterior chamber, which increases the risk of iatrogenic complications (injury to the choroid, cilichoroidal detachment, hyphema, infection). If the sharp needle is displaced relative to the injector cannula, damage to the iris, lens, ciliary body is possible, which can lead to complications such as bleeding in the eye cavity, detachment of the Descemet's membrane, the development of traumatic cataracts, which will lead to a permanent decrease in vision, will require repeated surgical interventions. The operation of this device requires additional means of visual control of the anterior chamber angle during implantation, which complicates the surgical intervention and increases its duration. In addition, the complexity and multicomponent nature of the device can cause difficulties in its operation, breakdowns, the device is disposable, used for one operation, since its pre-sterilization processing and sterilization is impossible.

The task is to create a device for implantation of polymer shunts, including elastic antiglaucomatous shunts, which reduces the duration of the operation, the risk of iatrogenic complications during implantation, and the risk of damage to the shunt during implantation.

EFFECT: reduced risk of damage, destruction of the shunt during implantation.

The technical result is achieved by a device that includes a body with a slot for the slider, the working distal end of the body contains a hollow tip with an oblique cut corresponding to the inclination of the shunt support element; a needle with a diameter corresponding to the inner diameter of the shunt placed inside the tip and connected to the rod; sleeve, bushing and spring at the proximal end of the stem.

The proposed utility model is illustrated by graphic materials:

Fig.1 - drawing of a general view of the device;

Fig. 2 – drawing of the device in a longitudinal section in the position before shunt installation (the distal end of the needle is extended from the tip due to the displacement of the slider to the extreme distal position (forward));

Fig. 3 - drawing of the device in a longitudinal section in the position after the installation of the shunt;

Fig. 4 - photograph of the device tip with a shunt put on the extended end of the needle.

The device for implantation of a flexible polymeric shunt (Fig.1) is a single structure and consists of a body (1) with a slot (2) for the slider (3) with a washer (4), a hollow tip (5) of the body having an oblique cut corresponding to inclination of the support element of the shunt. Inside the tip there is a needle (6) with a diameter corresponding to the inner diameter of the shunt. The needle is connected by its proximal end to the rod (7). The stem is attached to a sleeve (8) and passes through a bushing (9) which serves as a stop for a spring (10) located at the proximal end of the stem. The outer diameter of the spring matches the inner diameter of the body, ensuring smooth sliding over it.

A device for implanting a flexible polymeric shunt was made, containing a titanium body with two zones with circular notches for ease of holding in the surgeon's hand and a groove for moving the slider, with a high-carbon steel tip tightly inserted into the front of the body. The high-carbon steel needle is a guide for the inserted shunt, and the outer diameter of the needle corresponds to the inner diameter of the shunt, due to which the flexible shunt is rigidly fixed on the needle at the time of implantation, which ensures the accuracy of insertion and positioning of the shunt in the operating area and eliminates the possibility of its migration during the introduction . Due to the fact that the tip has an oblique cut with an inclination of 45°, corresponding to the inclination of the shunt support element, and the needle is located inside the tip, when the distal end of the shunt is pressed against the tissue in the operating area, it allows you to keep it (the shunt) inside the tissue during removal from the shunt needles, being a persistent platform for the shunt. A high-carbon steel rod is located inside the injector body with the possibility of free reciprocating movement inside the body. A fluoroplastic sleeve is tightly fitted on the stem distal to the restrictive washer to ensure the sliding and smooth movement of the stem and fixing the spring. Between the clutch and the spring there is a thrust bushing. A high-carbon steel slider with a notch for the surgeon's finger provides shaft mobility by moving along the body and allows you to push the end of the needle into the tip after the completion of the shunt implantation. A BRP stop washer located under the slider restricts forward movement of the stem and ensures that the slider moves smoothly into the slots by sliding along the injector body. A high carbon steel screw in the hole under the slider secures the stem. A second high carbon steel screw is screwed into the distal end of the housing to seal it. Due to the materials from which the device is made, the simplicity of the design, it can be easily disassembled, subject to pre-sterilization processing and sterilization.

The device is used as follows.

After separating the conjunctiva in the selected area, cutting out a superficial scleral flap and forming a deep sclera flap under it near the limbus with the capture of the transition zone for immersion of the supporting elements of the polymer, including the elastic glaucoma shunt under the deep sclera flap, in the zone of the transitional part of the limbus, a hole is marked with a 23G needle parallel to the plane of the iris. The device is brought into position by moving the slider in the slot so (Figure 2) that the needle comes out of the tip at a distance of at least 2/3 of the length of the polymeric glaucoma bypass (hereinafter referred to as the shunt). The slot is made in such a way that when the needle is brought into the working position, the length of the shunt will exceed the length of the extended needle by no more than 1/3. A shunt is put on the needle until it stops with the distal end of the device tip having an oblique cut with an inclination of 45°, corresponding to the inclination of the shunt support element, providing tight contact due to the coincidence of the tip and shunt cuts, which prevents the shunt from “turning” on the needle. A shunt is inserted through the intended opening into the anterior chamber in such a way that the supporting element of the shunt remains under the deep scleral flap. Then, by smoothly moving the slider back until it stops at the proximal edge of the slot (Fig. 3), the needle is removed from the shunt, while the edge of the tip serves as a stop, which ensures that the shunt is fixed in the installed position. After removing the needle from the shunt, sutures are applied to the superficial scleral flap, Tenon's capsule and conjunctiva.

An example of using the proposed device

Patient S., 68 years old, complained of decreased vision in the left eye. She has been observed for glaucoma for more than 3 years, instills "kosopt" and "travatan" into the left eye. Intraocular pressure of the left eye - 30-32 mm Hg. Art. marginal excavation of the ONH in three segments, narrowing of the visual field in the nasal segments by more than 15° from the fixation point, visual acuity 0.1 n/a. Diagnosis: Unstabilized open-angle III "B" glaucoma of the left eye. Operation technique. After separating the conjunctiva in the upper sections, 4-5 mm from the limbus and diathermy coagulation, a superficial scleral flap 3.5 × 3.5 mm was cut out for 1/3 of its thickness, a deep sclera flap was formed under it from the limbus, 2.0 × 2, 0 mm, a deep flap was excised with the capture of the corneal part of the limbus, in the transition zone of the limbus, a hole was marked with a 23G needle, parallel to the plane of the iris, with access to the anterior chamber, the anterior chamber was filled with viscoelastic based on hyaluronic acid. Before implantation, the device was brought into working position by moving the slider in the slot to the extreme distal position. The needle went out to a distance of 2.0 mm. A polymeric shunt 3 mm long and 0.5 mm wide (with a supporting element located at an angle of 45° to the longitudinal axis of the shunt, 1.2 mm wide) was put on the needle until it stops against the distal end of the device tip, which has an oblique cut with an inclination of 45 °. The shunt exceeded the length of the needle by 1.0 mm (Fig. 4). A shunt was inserted through the intended hole so that its distal part was in the anterior chamber, and the part with the supporting element remained outside and was located under the superficial flap, tightly adhering to the sclera. Then, by smoothly moving the slider until it stops at the proximal edge of the slot, the needle was removed from the shunt. After the needle was removed from the shunt, the superficial scleral flap, Tenon's capsule, and conjunctiva were sutured with 10.0 nylon. The shunt kept the correct position in the scleral pocket in relation to the structures of the angle of the anterior chamber of the eye, without contact with the posterior surface of the cornea, the anterior surface of the iris and the lens. The postoperative period proceeded without complications. The patient received anti-inflammatory and antibiotic therapy. Discharged with IOP 17 mm Hg. Art. On re-examination after 3 months, the pressure is normalized (18 mm Hg). No complaints, shunt position is correct, visual functions are stable.

The proposed device allows you to keep the shunt inside the tissue in the process of removing the needle from the shunt, and the oblique cut of the tip, corresponding to the inclination of the supporting elements of the shunt, ensures its secure fixation on the device, prevents the rotation of the shunt on the needle, while there is no concentric pressure on the body of the shunt, as a result of which there is no risk of destruction or damage. At the same time, in order to achieve stabilization of the shunt during implantation, there is no need to complicate the design by creating an additional guiding part of the device located on top of the shunt. During the operation, the shunt is implanted through a micro-hole in the limbal zone of the outer capsule of the eye; the device tip does not penetrate into the anterior chamber; the supporting elements of the shunt remain under a deep scleral flap, which reduces the risk of iatrogenic complications during implantation. The slider slot allows the needle to be withdrawn from the device at a predetermined distance. A spring at the proximal end of the device body ensures smooth movement of the stem when the shunt is “removed” from the needle. When using the device, there is no need to make efforts to control the accuracy of insertion, the need for instrumental control of the insertion of the shunt into the cavity of the anterior chamber disappears, and the operation time is reduced.

Claims (1)

A device for implanting a polymer glaucoma shunt, comprising a body with a slot for a slider, characterized in that the working distal end of the body contains a hollow tip with an oblique cut corresponding to the inclination of the shunt support element, a needle with a diameter corresponding to the inner diameter of the shunt, placed inside the tip and connected by a proximal the end with the rod, while the rod is fastened to the coupling and passes through the sleeve, made with the possibility of a stop for the spring at the proximal end of the rod, and the rod is made with the possibility of reciprocating movement inside the body using a slider.

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