Aqueous humor drainage device for adjusting intraocular pressure and manufacturing method thereof

Abstract

Provided are an aqueous humor drainage device capable of preventing low intraocular pressure by reducing the effective inner diameter of an aqueous drainage path even when a tube having a large inner diameter is used, and a manufacturing method thereof. The aqueous humor drainage device comprises: a first tube having a first end portion and a second end portion at both opened ends thereof, allowing aqueous humor to be introduced into the anterior chamber of the eyeball via the first end portion, and discharging the introduced aqueous humor to a subconjunctival space or the outside via the second end portion; and a second tube having a third end portion and a fourth end portion at both open ends thereof and coupled to the inner circumferential surface of the first tube. Here, the third end portion is disposed between the first end portion and the second end portion, the fourth end portion is disposed to overlap the second end portion, and the first tube and the second tube are integrally formed by being made of the same material.

Description

Aqueous drainage device for controlling intraocular pressure and method for manufacturing the same

[0001] The present invention relates to an aqueous outflow device for controlling intraocular pressure, which can prevent hypotension caused by excessive outflow of aqueous humor when draining it from the anterior chamber to lower intraocular pressure in glaucoma surgery, and a method for manufacturing the same.

[0002] Aqueous humor, or aqueous humor, is a clear fluid that fills the space between the cornea and iris (the anterior chamber) and between the iris and lens (the posterior chamber). It has similar properties to lymph. Aqueous humor helps maintain pressure within the eye.

[0003] Meanwhile, glaucoma is a progressive optic neuropathy that causes dysfunction of the optic nerve and visual field loss. The primary cause of glaucoma is damage to the optic nerve due to increased intraocular pressure. Intraocular pressure refers to the pressure within the eye (eyeball) and is primarily determined by the balance of the aqueous humor circulation. Aqueous humor is produced daily in small amounts in the ciliary body behind the iris, and the amount produced is drained through the circulation. If excessive aqueous humor production occurs or drainage is reduced due to a disruption in circulatory flow, the pressure within the eye increases. This process leads to increased intraocular pressure and glaucoma. If this increased intraocular pressure persists, it can lead to permanent vision loss. Furthermore, in people with weak optic nerves, pressure-induced damage to the optic nerve can occur even at normal intraocular pressure, leading to glaucoma.

[0004] Glaucoma begins with damage to the optic nerve, making it difficult to restore the damage already done. Therefore, the goal of all treatment is to prevent further damage. Medications are typically used to lower intraocular pressure. However, if intraocular pressure remains uncontrolled despite multiple medications or if medication side effects prevent the use of medications, surgical treatments such as trabeculectomy and drainage device implantation are considered.

[0005] The Ahmed glaucoma valve is currently the most commonly used aqueous outflow device for glaucoma surgery in Korea (see US Pat. No. 5,071,508). The Ahmed valve consists of a silicone tube inserted into the anterior chamber to drain the aqueous humor. The inner diameter of the silicone tube is 300 µm. To prevent hypotension, a valve body is connected to the silicone tube. This valve body closes when intraocular pressure is low and opens only when intraocular pressure is high.

[0006] However, when the valve body is inserted under the conjunctiva, it can cause a foreign body sensation in the patient, and furthermore, there are many cases of postoperative hypotony due to the membrane responsible for opening and closing the valve body not functioning properly. Hypotony caused by excessive aqueous outflow can lead to choroidal detachment and retinal wrinkles (hypotonic retinopathy). Therefore, in actual clinical practice, methods such as inserting a stent into the tube or tying the tube to reduce its internal diameter are often used.

[0007] Meanwhile, there have been attempts to maintain the minimum intraocular pressure (6 mmHg) without a valve body by reducing the inner diameter of the silicone tube in the aqueous outflow device. However, due to the characteristics of silicone material and extrusion molding, it is difficult to produce a tube with an inner diameter of less than 100 µm. Furthermore, even with a tube diameter of 100 µm, maintaining the minimum intraocular pressure of 6 mmHg requires a tube length of at least 708 mm according to Poiseuille's law, making it difficult to apply this method to actual eyes.

[0008] The problem to be solved by the present invention is to provide an aqueous drainage device that can prevent hypotony by reducing the effective inner diameter of the aqueous drainage path even when using a tube with a large inner diameter.

[0009] Another problem that the present invention seeks to solve is to provide a method for manufacturing such a waterproof drainage device.

[0010] The problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned can be clearly understood by a person having ordinary skill in the technical field to which the present invention belongs from the description below.

[0011] According to one embodiment of the present invention for achieving the above object, an intraocular pressure control aqueous drainage device comprises: a first tube having a first end and a second end at each of the opened ends, through which aqueous humor flows into the anterior chamber of the eyeball and through which the second end discharges the introduced aqueous humor into the subconjunctival space or the outside; and a second tube having a third end and a fourth end at each of the opened ends and coupled to the inner circumferential surface of the first tube. Here, the third end is disposed between the first end and the second end, the fourth end is disposed to overlap the second end, and the first tube and the second tube are formed integrally by being made of the same material.

[0012] The first tube and the tube may be made of silicone.

[0013] The first tube may be formed into an annular shape with a constant inner diameter, and the second tube may be formed into an annular shape with an inner diameter that decreases from the third end to the fourth end.

[0014] The outer surface of the first tube adjacent to the second end may further include a coating layer. The coating layer may be made of a drug comprising a fibrosis inhibitor or an antibiotic; and a biodegradable polymer.

[0015] The above-mentioned anti-fibrotic agent may be composed of one or more selected from the group consisting of paclitaxel, 5-fluorouracil, and ibuprofen.

[0016] According to one embodiment of the present invention for achieving the above-described other object, a method for manufacturing an intraocular pressure control drainage device comprises the steps of: inserting a molding rod having a diameter smaller than the inner diameter of a first tube manufactured by extrusion molding into the first tube (both ends of the first tube are defined as a first end and a second end, respectively); immersing the second end of the first tube in a silicone solution while the molding rod is inserted; forming a negative pressure within the first tube to suck the silicone solution into the first tube; and removing the molding rod when the silicone solution hardens to form a second tube made of the silicone solution within the first tube (both ends of the second tube are defined as a third end and a fourth end, respectively). Here, the third end is disposed between the first end and the second end, the fourth end is disposed to overlap the second end, and the first annular tube and the second annular tube are made of the same material and are integrally formed.

[0017] The method may further include a step of applying a coating layer to the outer surface of the first tube adjacent to the second end. The coating layer may be made of a drug comprising a fibrosis inhibitor or an antibiotic; and a biodegradable polymer compound.

[0018] The above-mentioned anti-fibrotic agent may be composed of one or more selected from the group consisting of paclitaxel, 5-fluorouracil, and ibuprofen.

[0019] The first tube may have a length of 6-200 mm, an outer diameter of 140-200 um, and an inner diameter of 70-150 um, and the second tube may have a length of 0.5-2 mm, an outer diameter of 70-150 um, and an inner diameter of 10-40 um.

[0020] The above antibiotic may be composed of one or more selected from the group consisting of penicillin antibiotics, aminoglycoside antibiotics, tetracycline antibiotics, and quinolone antibiotics.

[0021] The biodegradable polymer may be composed of at least one selected from the group consisting of PEG (polyetheleneglycol), PLGA (poly(lactide-co-glycolide)), SIBS (poly(styrene-b-isobutylene-b-styrene)), PGA (polyglycolide), PLA (polylactide), and PCL (polycaprolactone).

[0022] Specific details of other embodiments are included in the specific contents and drawings.

[0023] As described above, according to the aqueous outflow device for controlling intraocular pressure and the method for manufacturing the same according to the present invention, a forming rod is inserted into a first tube having a relatively large inner diameter manufactured by extrusion molding, the tube is immersed in a silicone solution, and then a second tube having a relatively small inner diameter is formed within the first tube using negative pressure. In the case of the aqueous outflow device composed of the first tube and the second tube formed integrally with the same material, the effective inner diameter or effective cross-sectional area is reduced, so that even if the length of the aqueous outflow device is short, the minimum intraocular pressure can be maintained.

[0024] In addition, since the waterproof drainage device of the present invention does not require a separate opening / closing valve, the foreign body sensation can be minimized.

[0025] Figure 1 is a cross-sectional view showing an eye in which a waterproof drainage device according to one embodiment of the present invention has been implanted.

[0026] Figure 2 is an enlarged drawing of the waterproof drain device of Figure 1.

[0027] Figure 3 is a perspective view showing the waterproof drain device of Figure 1.

[0028] Fig. 4 is a partial cutaway perspective view showing the waterproof drain device of Fig. 3.

[0029] Fig. 5 is a cross-sectional view of the waterproof drain device of Fig. 3 taken along line AA'.

[0030] Fig. 6 is a cross-sectional view of the waterproof drain device of Fig. 3 taken along line BB'.

[0031] FIG. 7 is a drawing sequentially showing a method for manufacturing a waterproof drainage device according to one embodiment of the present invention.

[0032] Figure 8 is a longitudinal cross-sectional view showing a waterproof drainage device according to another embodiment of the present invention.

[0033] Figure 9 is a longitudinal cross-sectional view showing a waterproof drainage device according to another embodiment of the present invention.

[0034] The advantages and features of the present invention, and the methods for achieving them, will become clearer with reference to the embodiments described in detail below together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms. These embodiments are provided only to ensure that the disclosure of the present invention is complete and to fully inform those skilled in the art of the scope of the invention, and the present invention is defined only by the scope of the claims. Like reference numerals designate like elements throughout the specification.

[0035]

[0036] Hereinafter, a waterproof drainage device according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 6. FIG. 1 is a cross-sectional view showing an eye in which a waterproof drainage device according to an embodiment of the present invention is implanted. FIG. 2 is an enlarged view of the waterproof drainage device of FIG. 1. FIG. 3 is a perspective view showing the waterproof drainage device of FIG. 1. FIG. 4 is a partial cutaway perspective view showing the waterproof drainage device of FIG. 3. FIG. 5 is a longitudinal cross-sectional view of the waterproof drainage device of FIG. 3 taken along line AA'. FIG. 6 is a cross-sectional view of the waterproof drainage device of FIG. 3 taken along line BB'.

[0037] An aqueous drainage device (200) according to one embodiment of the present invention is a device for controlling intraocular pressure for treating glaucoma, and includes a first tube (210) and a second tube (220).

[0038] The first tube (210) is manufactured by extrusion molding and has an overall tube or cylinder shape. The first tube (210) has a first end (212) and a second end (214) at each of the open ends. The first end (212) of the first tube (210) is positioned in the front (25) of the eyeball (100), and the second end (214) of the first tube (210) is positioned between the conjunctiva (30) and the sclera (10), i.e., in the subconjunctival space, or is exposed to the outside through the conjunctiva (30).

[0039] An opening is formed in each of the first end (212) and the second end (214) of the first tube (210), and an aqueous humor channel is formed inside the first tube (210) to connect these openings. Since the first end (212) is positioned in the front (25) of the eyeball (100), the aqueous humor (60) in the front (25) flows into the aqueous humor drainage device (200) through the first end (212). The introduced aqueous humor moves along the aqueous humor channel and is then discharged into the subconjunctival space or to the outside through the second end (214). In the present embodiment, the first tube (210) is described as an example in which the first tube is formed of a single tube, but the present invention is not limited thereto, and a plurality of tubes may be connected to each other to form the first tube (210).

[0040] The second tube (220) is manufactured by a type of vacuum molding using the first tube (210) and the forming rod (300) as a mold, and is formed into a tube or cylinder shape overall. The second tube (220) has a third end (222) and a fourth end (224) at each of the open ends, and is coupled to the inner surface of the first tube (210). The third end (222) is positioned between the first end (212) and the second end (214), and the fourth end (224) is positioned to overlap the second end (214).

[0041] The first tube (210) and the second tube (220) are manufactured using different molding methods, but are formed as one piece using the same material. It is preferable that the first tube (210) and the second tube (220) be made of a material that is safe for the human body, maintains its shape well, and has flexibility so that it can bend well along the curvature of the eye. For example, the first tube (210) and the second tube (220) may be made of silicone, collagen gel, poly(methyl methacrylate), or poly(styrene-block-isobutylene-block-styrene). Preferably, the first tube (210) and the second tube (220) may be made of silicone.

[0042] For example, the first tube (210) may have a length (L1) of 6-200 mm, an outer diameter (D1) of 140-200 um, and an inner diameter (D2) of 70-150 um. Since the first tube (210) is made of silicone or the like and is manufactured by extrusion molding, it is difficult to make the inner diameter (D2) of the first tube (210) smaller than 70 um.

[0043] For example, the second tube (220) may have a length (L2) of 0.5-2 mm, an outer diameter (D2) of 70-150 μm, and an inner diameter (D3) of 10-40 μm. The second tube (220) is made of the same material as the first tube (210), but is manufactured by a vacuum forming method using a forming rod (300) as a mold, so that the inner diameter (D3) of the second tube (220) can be made smaller than 40 μm by adjusting the diameter of the forming rod (300). The length (L2) of the second tube (220) is preferably 1 to 70% of the length (L1) of the first tube (210).

[0044] The water (60) in the front (25) flows into the water discharge device (200) through the first end (212) of the first tube (210) and is then discharged through the fourth end (224) of the second tube (220). The inner diameter (D3) of the fourth end (224) is smaller than the inner diameter (D2) of the first end (212). Therefore, since the water velocity (V2) in the fourth end (224) increases more than the water velocity (V1) in the first end (212), the probability that bacteria outside the human body will flow against the flow of the water (60) and enter the front (25) can be reduced.

[0045] Although not shown, an annular catch (not shown) may be formed along the outer circumference of the side or outer surface of the first tube (210). The catch or at least a portion of the catch may have a shape in which the thickness increases from the first end (212) to the second end (214) of the first tube (210). Due to the shape of the catch, the aqueous drainage device (200) can be easily inserted into the eyeball (100) during surgery, but it is not easy to remove the aqueous drainage device (200) located on the sclera (10) after a period of time after surgery. Therefore, the catch prevents the aqueous drainage device (200) from detaching from the sclera (10) and prevents aqueous from leaking around the first tube (210) in the early stage of surgery.

[0046] In general, when a fluid passes through a pipe, the pressure difference (Δp) across the two ends of the pipe is determined by the following mathematical equation 1 according to Poiseuille's law.

[0047] [Mathematical Formula 1]

[0048]

[0049] Here, μ is the viscosity, L is the length of the pipe, Q is the volume flow rate, and R is the radius. When the volume flow rate of the water is constant, the pressure difference (Δp) across the two ends of the pipe is proportional to the length of the pipe (L) and inversely proportional to the fourth power of the radius of the pipe (or the square of the cross-sectional area).

[0050] In general, it is known that the minimum intraocular pressure (6 mmHg) for normal eye structure and function can be maintained when the length (L) of the tube is 6 mm and the inner diameter (2R) of the tube is 35 μm according to mathematical formula 1. If the aqueous drainage device (200) does not have the second tube (220) and the inner diameter of the first tube (210) is 100 μm, the pressure difference (Δp) drops below 0.1 mmHg, resulting in hypotony. Therefore, in order to prevent hypotony, the effective inner diameter or effective cross-sectional area of ​​the first tube (210) must be reduced. In the present invention, by integrally forming the second tube (220) within the first tube (210), the effective inner diameter or effective cross-sectional area of ​​the first tube (210) is greatly reduced, thereby preventing hypotony. Based on Poiseuille's law, the length (L1) and inner diameter (D2) of the first tube (210) and the length (L2) and inner diameter (D3) of the second tube (220) can be organically selected so that a flow rate of 3 to 4 mL (daily production volume of waterproof water) is generated for 24 hours at a water pressure of 6 to 12 mmHg.

[0051] In Fig. 1, the unexplained drawing reference numeral 20 represents the cornea, 40 represents the lens, and 50 represents the iris.

[0052] In this embodiment, a case where the waterproof drain device (200) is used as a complete unit is described as an example, but the present invention is not limited thereto. That is, the waterproof drain device (200) may be used in a form in which it is joined to or constitutes a part of an existing waterproof drain device.

[0053]

[0054] Hereinafter, a method for manufacturing a waterproof drainage device according to an embodiment of the present invention will be described in detail with reference to FIG. 7. FIG. 7 is a drawing sequentially showing a method for manufacturing a waterproof drainage device according to an embodiment of the present invention.

[0055] Referring to Fig. 7(a), after manufacturing a first tube (210) by extrusion molding, a molding rod (300) having a diameter smaller than the inner diameter (D2) of the first tube (210) is inserted into the first tube (210). Here, the molding rod (300) is formed in an overall rod shape or a cylindrical shape. The length of the molding rod (300) is preferably larger than the length (L1) of the first tube (210), and it is preferable that both ends of the molding rod (300) are exposed to the outside when the molding rod (300) is inserted into the first tube (210). The diameter of the molding rod (300) is preferably smaller than the inner diameter (D2) of the first tube (210). Since the inner diameter (D3) of the second tube (220) to be subsequently manufactured is determined by the diameter of the forming rod (300), the diameter of the forming rod (300) may be 10 to 40 um. It is preferable that the forming rod (300) be arranged spaced apart from the inner surface of the first tube (210). In some cases, even if the forming rod (300) makes two-dimensional linear contact with the inner surface of the second tube (220), the present invention can obtain substantially the same function and effect.

[0056] It is preferable that the forming rod (300) be made of a material that is easily physically separated from the silicone solution when it is cured, and may be made of, for example, polypropylene, stainless steel, etc.

[0057] Referring to Fig. 7(b), a molten silicone solution (320) is prepared inside a container (310), and the second end (214) of the first tube (210) is immersed in the silicone solution (320) with the molding rod (300) inserted therein.

[0058] Referring to Fig. 7(c), a negative pressure is formed within the first tube (210) to suck the silicone solution (320) into the first tube (210). For example, a negative pressure pump or the like can be connected to the first end (212) of the first tube (210) to form the negative pressure.

[0059] Referring to Fig. 7(d), the first tube (210) is separated from the container (310), and when the silicone solution (320) is cured, the molding rod (300) is removed. As a result, a second tube (220) in which the silicone solution is cured is created within the first tube (210).

[0060] Referring to Fig. 7(e), the end of the first tube (210) immersed in the silicone solution (320) is cut along the CC' line.

[0061] Through the above process, the third end (222) of the second tube (220) is placed between the first end (212) and the second end (214) of the first tube (210), and the fourth end (224) of the second tube (220) is placed so as to overlap the second end (214) of the first tube (210). Although the manufacturing methods of the first tube (210) and the second tube (220) are different, since the materials of the first tube (210) and the second tube (220) are the same and the second tube (220) is formed by curing the silicone solution (320), the first tube (210) and the second tube (220) are integrally joined to each other even without a separate adhesive between them.

[0062]

[0063] Hereinafter, a waterproof drainage device according to another embodiment of the present invention will be described in detail with reference to FIG. 8. FIG. 8 is a longitudinal cross-sectional view showing a waterproof drainage device according to another embodiment of the present invention. For convenience of explanation, components having the same function as those shown in the drawings of the previous embodiments (FIGS. 1 to 7) are denoted by the same reference numerals, and their descriptions are omitted. The following description focuses on the differences.

[0064] The first tube (210) is formed in an annular shape with a constant inner diameter (D2), and the second tube (221) is formed in an annular shape with an inner diameter (D3) that decreases from the third end (222) to the fourth end (224). In this way, when the inner diameter (D3) of the second tube (221) has different values ​​depending on the location, the aqueous discharge flow rate can be controlled by cutting one end (the second end and the fourth end) of the aqueous discharge device (201) at a desired location according to the patient's condition during surgery.

[0065] The manufacturing method of the waterproof drain device (201) according to the present embodiment is substantially the same as the manufacturing method according to the previous embodiment, except for the following. That is, in the present embodiment, the end of the forming rod has a tapered shape.

[0066]

[0067] Hereinafter, a waterproof drainage device according to another embodiment of the present invention will be described in detail with reference to FIG. 9. FIG. 9 is a longitudinal cross-sectional view showing a waterproof drainage device according to another embodiment of the present invention. For convenience of explanation, components having the same function as those shown in the drawings of the previous embodiments (FIGS. 1 to 7) are denoted by the same reference numerals, and their descriptions are omitted. The following description focuses on differences.

[0068] The waterproofing device (202) according to the present embodiment further includes a coating layer (230) applied to the outer surface of the first tube (210) adjacent to the second end (214). The coating layer (230) may be applied to the outer surface of the first tube (210) after the silicone solution (320) is cured in FIG. 7(d), or may be applied to the outer surface of the first tube (210) after the end of the first tube (210) is cut in FIG. 7(e).

[0069] The coating layer (230) is composed of a drug and a biodegradable polymer, and the drug may be a fibrosis inhibitor or an antibiotic. After the aqueous humor drainage device (202) is inserted into the eyeball (100), over time, the biodegradable polymer begins to be absorbed into the surrounding tissues, and the drug gradually begins to take effect.

[0070] The anti-fibrosis agent is a substance that suppresses fibrosis in the tissue surrounding the drainage device (202), and may be composed of, for example, one or more selected from the group consisting of paclitaxel, 5-fluorouracil, and ibuprofen. The antibiotic may be composed of one or more selected from the group consisting of penicillin antibiotics, aminoglycoside antibiotics, tetracycline antibiotics, and quinolone antibiotics. The biodegradable polymer may be composed of one or more selected from the group consisting of PEG (polyetheleneglycol), PLGA (poly(lactide-co-glycolide)), SIBS (poly(styrene-b-isobutylene-b-styrene)), PGA (polyglycolide), PLA (polylactide), and PCL (polycaprolactone).

[0071] If the aqueous drainage device (202) is inserted into the eye (100) such that the first end (212) of the first tube (210) is positioned in the anterior chamber (25) of the eye (100) and the second end (214) of the first tube (210) is positioned between the conjunctiva (30) and the sclera (10), i.e., in the subconjunctival space, the coating layer (230) is preferably formed of a drug comprising a fibrosis inhibitor and a biodegradable polymer to suppress fibrosis around the second end (214). If the drug or the fibrosis inhibitor flows into the anterior chamber (25), it may cause damage to corneal endothelial cells, so the coating layer (230) is preferably applied to only 10 to 40% of the first tube (210) from the second end (214).

[0072] If the aqueous drainage device (202) is inserted into the eye (100) such that the first end (212) of the first tube (210) is placed in the front (25) of the eye (100) and the second end (214) of the first tube (210) is exposed to the outside through the conjunctiva (30), the coating layer (230) is preferably made of a drug including an antibiotic and a biodegradable polymer to block external bacteria from penetrating through the second end (214).

[0073]

[0074] Although the embodiments of the present invention have been described with reference to the attached drawings, those skilled in the art will appreciate that the present invention can be implemented in other specific forms without altering the technical concept or essential features thereof. Therefore, the embodiments described above should be understood to be illustrative in all respects and not restrictive.

Claims

1. As an aqueous outflow device for controlling intraocular pressure, A first tube having a first end and a second end at each of the open ends, wherein aqueous humor flows into the anterior chamber of the eye through the first end and the introduced aqueous humor is discharged into the subconjunctival space or the outside through the second end; and A second tube having a third end and a fourth end at the open ends and coupled to the inner surface of the first tube, The third end is positioned between the first end and the second end, and the fourth end is positioned to overlap the second end. A waterproof drain device characterized in that the first tube and the second tube are formed integrally by being made of the same material.

2. In paragraph 1, A waterproof drain device characterized in that the first tube and the tube are made of silicone.

3. In paragraph 1, A waterproof drainage device characterized in that the first tube is formed in an annular shape with a constant inner diameter, and the second tube is formed in an annular shape with an inner diameter that decreases from the third end to the fourth end.

4. In paragraph 1, A waterproof drainage device further comprising a coating layer applied to the outer surface of the first tube adjacent to the second end, wherein the coating layer comprises a drug comprising a fibrosis inhibitor or an antibiotic; and a biodegradable polymer.

5. In paragraph 4, A drainage device characterized in that the above-mentioned anti-fibrosis agent comprises at least one selected from the group consisting of paclitaxel, 5-fluorouracil, and ibuprofen.

6. A method for manufacturing an aqueous outflow device for controlling intraocular pressure, A step of inserting a forming rod having a diameter smaller than the inner diameter of the first tube into a first tube manufactured by extrusion molding (both ends of the first tube are defined as a first end and a second end, respectively); A step of immersing the second end of the first tube in a silicone solution while the forming rod is inserted; A step of forming negative pressure within the first tube and sucking the silicone solution into the first tube; and When the silicone solution is hardened, the forming rod is removed to form a second tube made of the silicone solution within the first tube (both ends of the second tube are defined as the third end and the fourth end, respectively). The third end is positioned between the first end and the second end, and the fourth end is positioned to overlap the second end. A method for manufacturing a waterproof drainage device, characterized in that the first annular tube and the second annular tube are formed integrally by being made of the same material.

7. In paragraph 6, A method for manufacturing a waterproof drainage device, further comprising a step of applying a coating layer to the outer surface of the first tube adjacent to the second end, wherein the coating layer is made of a drug comprising a fibrosis inhibitor or an antibiotic; and a biodegradable polymer compound.

8. In paragraph 7, A method for manufacturing a waterproof drainage device, characterized in that the above-mentioned anti-fibrosis agent comprises at least one selected from the group consisting of paclitaxel, 5-fluorouracil, and ibuprofen.

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