Gastrostomy catheter and capsule cover

Abstract

To provide a gastrostomy catheter equipped with a capsule cover 70 manufactured into a desired shape with good reproducibility.SOLUTION: A gastrostomy catheter 100 includes: a catheter body 1 having a shaft 10 equipped with a lumen 11 and a body surface abutment part; a bumper 50 provided in the lower end part of the shaft 10, which expands in the stomach; and a capsule cover 70 for keeping the bumper 50 in a contracted state. At the time of detention, the capsule cover 70 is separated from the catheter body and the bumper 50 expands. The surface roughness of an inner surface 70a of the capsule cover 70 is smaller than that of an outer surface 70b of the capsule cover 70.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a gastrostomy catheter and a capsule cover. [Background technology]

[0002] An example of a gastrostomy catheter is described in Patent Document 1. The gastrostomy catheter in Patent Document 1 comprises a catheter body having a shaft with a lumen and a body surface contact portion, a bumper that is provided at the lower end of the shaft and expands inside the stomach, and a capsule cover that maintains the bumper in a contracted state; when the catheter is placed, the capsule cover detaches from the catheter body and the bumper expands. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2019-98146 Summary of the Invention [Problem to be solved by the invention]

[0004] According to the investigations of the present inventors, the gastrostomy catheter of Patent Document 1 still has room for improvement in terms of producing a capsule cover in a desired shape with good reproducibility.

[0005] The present invention has been made in view of the above problems, and provides a gastrostomy catheter equipped with a capsule cover that is manufactured in a desired shape with good reproducibility, and a capsule cover. [Means for solving the problem]

[0006] According to the present invention, there is provided a gastrostomy catheter comprising: a catheter body having a shaft with a lumen and a body surface abutment portion; a bumper provided at the lower end of the shaft and expanding within the stomach; and a capsule cover for maintaining the bumper in a contracted state, wherein the capsule cover detaches from the catheter body during placement, causing the bumper to expand, The gastrostomy catheter is provided such that the surface roughness of the inner surface of the capsule cover is less than the surface roughness of the outer surface of the capsule cover.

[0007] According to the present invention, there is also provided a capsule cover for a gastrostomy catheter, the capsule cover comprising: a catheter body having a shaft with a lumen and a body surface abutment portion; a bumper provided at the lower end of the shaft and expanding within the stomach; and a capsule cover for maintaining the bumper in a contracted state, wherein the capsule cover detaches from the catheter body during placement, causing the bumper to expand, A capsule cover is provided, the surface roughness of the inner surface of the capsule cover being less than the surface roughness of the outer surface of the capsule cover. [Effects of the Invention]

[0008] According to the present invention, it is possible to provide a gastrostomy catheter equipped with a capsule cover that is manufactured in a desired shape with good reproducibility. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a perspective view of a gastrostomy catheter according to an embodiment. [Figure 2] FIG. 1 is a longitudinal cross-sectional view of a gastrostomy catheter according to an embodiment. [Figure 3] FIG. 10 is a diagram for explaining the operation when placing a gastrostomy catheter according to an embodiment, showing the state in which the gastrostomy catheter with an obturator attached has been inserted into the fistula. [Figure 4]4(a) and 4(b) are diagrams for explaining the operation when placing a gastrostomy catheter according to the embodiment. Of these, FIG. 4(a) shows a state in which the inner tubular part is pushed downward relative to the outer tubular part, and FIG. 4(b) shows a state in which the obturator has been removed from the gastrostomy catheter. [Figure 5] FIG. 2 is a perspective view of a capsule cover according to an embodiment. [Figure 6] FIG. 2 is a cross-sectional view of a capsule cover according to an embodiment. [Figure 7] FIG. 7(a) is a vertical cross-sectional view of a capsule cover in the embodiment, and FIG. 7(b) is a partially enlarged view of part A shown in FIG. 7(a). [Figure 8] Figures 8(a) and 8(b) are schematic enlarged partial views of the outer surface of the capsule cover in the embodiment, where Figure 8(a) shows the upper part of the capsule cover and Figure 8(b) shows the lower part of the capsule cover. [Figure 9] 1 is a schematic partial enlarged view of a capsule cover in an embodiment, showing the inner surface of the upper end portion of the capsule cover. FIG. [Figure 10] Figures 10(a) and 10(b) are figures for explaining an example of a method for producing a capsule cover in an embodiment, where Figure 10(a) shows a state in which a pair of half outer molds are clamped, and Figure 10(b) shows a state in which the pair of half outer molds are open. [Figure 11] 11(a) and 11(b) are diagrams for explaining an example of a method for producing a capsule cover in the embodiment, and show the process of removing the capsule cover from the inner mold. [Figure 12] Figures 12(a) and 12(b) are images showing the outer surface of the capsule cover in the embodiment, where Figure 12(a) shows the upper part of the capsule cover and Figure 12(b) shows the lower part of the capsule cover. [Figure 13] Figures 13(a) and 13(b) are images showing the inner surface of the capsule cover in the embodiment, of which Figure 13(a) shows the upper part of the capsule cover and Figure 12(b) shows the lower part of the capsule cover. [Figure 14]1 is a diagram showing an image of the inner surface of a capsule cover in an embodiment, showing the inner peripheral surface of the upper end portion of the capsule cover. FIG. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, each embodiment of the present invention will be described with reference to the drawings. In all drawings, similar components are given the same reference numerals, and descriptions thereof will be omitted where appropriate. In addition, Figs. 2 to 4(b) are cross-sectional views taken along the axial direction of the shaft 10. In addition, Fig. 6 is a cross-sectional view taken along the radial direction of the capsule cover 70, and Fig. 7(a) is a cross-sectional view taken along the axial direction of the capsule cover 70. Furthermore, the various components of the gastrostomy catheter 100 of the present invention do not need to be independent entities. It is acceptable for multiple components to be formed as a single member, for one component to be formed from multiple members, for one component to be part of another component, or for part of one component to overlap with part of another component, etc. 2 will be referred to as "downward" and "upward" in the following description. The axial direction of the shaft 10 will sometimes be referred to simply as the "axial direction," and the radial direction of the shaft 10 will sometimes be referred to simply as the "radial direction." The circumferential direction of the shaft 10 will sometimes be referred to simply as the "circumferential direction."

[0011] As shown in FIGS. 1 and 2, the gastrostomy catheter 100 according to this embodiment comprises a catheter body 1 having a shaft 10 with a lumen 11 and a body surface contact portion 20, a bumper 50 provided at the lower end of the shaft 10 that expands within the stomach, and a capsule cover 70 that maintains the bumper 50 in a contracted state; when the catheter is placed, the capsule cover 70 detaches from the catheter body 1 and the bumper 50 expands. The surface roughness of the inner surface 70a of the capsule cover 70 is smaller than the surface roughness of the outer surface 70b of the capsule cover 70. In the present invention, the "surface roughness" refers to the arithmetic mean roughness ("surface roughness (Ra)") of the surface measured using a commercially available non-contact surface roughness measuring instrument in accordance with the provisions of JIS B0601 (1994).

[0012] Before the gastrostomy catheter 100 is placed, the bumper 50 is housed inside the capsule cover 70 in a contracted state (folded state) in which it is contracted in the radial direction. When placing the gastrostomy catheter 100, first, the lower end of the shaft 10 (and thus the capsule cover 70) is inserted into the lumen of the fistula 530 formed by penetrating the abdominal wall 510 and the stomach wall 520, and the bumper 50 is placed in the stomach. With the bumper 50 placed at a desired position in the stomach, the capsule cover 70 is detached from the bumper 50 using an insertion tool (for example, the obturator 200 shown in FIG. 5, etc.), causing the bumper 50 to expand radially due to its elastic restoring force and become engaged with the stomach wall 520. This allows the gastrostomy catheter 100 to be placed.

[0013] When producing the capsule cover 70, a mold 600 is used, which includes a pair of outer mold halves 610 and a rod-shaped inner mold 620 placed inside the outer mold 610. The pair of outer mold halves 610 determine the shape of the outer surface 70b of the capsule cover 70, and the inner mold 620 determines the shape of the inner surface 70a of the capsule cover 70. More specifically, a recess 612 is formed in each of the pair of outer mold halves 610. When the pair of outer mold halves 610 are clamped together, a cavity 614 is formed by the recess 612 of each of the pair of outer mold halves 610. As shown in FIG. 10( a), the inner mold 620 is inserted into the cavity 614, and in this state, a gap is formed between the inner mold 620 and the outer mold 610. A constituent material of the capsule cover 70, such as a heated and melted resin, is filled into the gap between the inner mold 620 and the outer mold 610. The filled resin is cooled and solidified inside the mold 600, thereby molding the capsule cover 70. Then, as shown in FIG. 10( b), the pair of outer mold halves 610 are opened, and the capsule cover 70 molded from the outer mold 610 is removed together with the inner mold 620. Next, as shown in Figures 11(a) and 11(b), the capsule cover 70 inserted onto the inner mold 620 is slid downward (pushed out) relative to the inner mold 620 along the axial direction of the inner mold 620, and the capsule cover 70 is removed from the inner mold 620. In this manner, the capsule cover 70 can be produced.

[0014] According to this embodiment, the surface roughness of the inner surface 70a of the capsule cover 70 is smaller than the surface roughness of the outer surface 70b of the capsule cover 70. This configuration improves the releasability of the capsule cover 70 (more specifically, the outer surface 70b) from the outer mold 610, while improving the adhesion of the capsule cover 70 (more specifically, the inner surface 70a) to the inner mold 620. Therefore, deformation of the capsule cover 70 can be suppressed when the capsule cover 70 is removed from the outer mold 610 together with the inner mold 620. Furthermore, since the frictional resistance (dynamic friction coefficient) between the inner surface 70a of the capsule cover 70 and the outer peripheral surface of the inner mold 620 can be reduced when the capsule cover 70 is slid downward relative to the inner mold 620 along the axial direction of the inner mold 620, the capsule cover 70 can be smoothly removed from the inner mold 620. Therefore, deformation of the capsule cover 70 can be suppressed when the capsule cover 70 is removed from the inner mold 620. As described above, according to this embodiment, it is possible to provide a gastrostomy catheter equipped with a capsule cover 70 that is produced in a desired shape with good reproducibility.

[0015] In the present invention, "the surface roughness of the inner surface 70a of the capsule cover 70 is smaller than the surface roughness of the outer surface 70b of the capsule cover 70" means that the surface roughness of at least a portion of the inner surface 70a of the capsule cover 70 is smaller than the surface roughness of at least a portion of the outer surface 70b of the capsule cover 70. Therefore, the entire surface roughness of the inner surface 70a of the capsule cover 70 may be smaller than the entire surface roughness of the outer surface 70b of the capsule cover 70, or the surface roughness of a portion of the inner surface 70a of the capsule cover 70 may be locally smaller than at least a portion of the outer surface 70b of the capsule cover 70. In the present embodiment, for example, the overall surface roughness of the inner surface 70a of the capsule cover 70 is smaller than the overall surface roughness of the outer surface 70b of the capsule cover 70.

[0016] The gastrostomy catheter 100 will be described in more detail below. In this embodiment, the inner cavity of the shaft 10 forms a lumen 11 . 1 and 2, the shaft 10 is formed in a cylindrical shape with its axial direction extending in the vertical direction. The outer diameter of the upper end of the shaft 10 is relatively larger than the outer diameter of the other parts of the shaft 10. A coupled part 30, which will be described later, is attached to the upper end of the shaft 10. The inner diameter of the upper end of the lumen 11 (the inner diameter of the upper end of the shaft 10) is, for example, relatively larger than other parts of the lumen 11, and forms a storage section in which the check valve 40 described later is stored. A wire lumen 12 is formed inside the tube wall of the shaft 10. One longitudinal end of the wire lumen 12 opens at the lower end of the shaft 10 and communicates with the inside of the bumper 50. The wire lumen 12 is disposed at a position offset radially outward from the lumen 11. A wire (not shown) for deploying the bumper 50 is inserted through the wire lumen 12.

[0017] 4(b), the body surface contact portion 20 is the portion exposed to the body surface of the living body when the gastrostomy catheter 100 is indwelling, and the lower surface of the body surface contact portion 20 faces the outer surface of the abdominal wall 510. The lower surface of the body surface contact portion 20 is formed flat. For example, a plug member 80 (see FIG. 1) is formed on the body surface contact portion 20. The plug member 80 is capable of closing an opening 31 on the upper end side of the connectable portion 30, which will be described below.

[0018] The shaft 10 and the body surface contact portion 20 are integrally molded from, for example, a resin material. The resin material is not particularly limited, but examples thereof include polyvinylidene fluoride resin, polytetrafluoroethylene resin, polyethylene resin, polypropylene resin, silicone rubber, and other rubber materials.

[0019] In this embodiment, as shown in FIGS. 1 and 2, the gastrostomy catheter 100 further includes a connection receiving portion 30 formed at the upper end of the body surface contact portion 20. The obturator 200 described above is detachably hooked to the connected portion 30. This allows the obturator 200 to be attached to the gastrostomy catheter 100. The coupled part 30 is formed, for example, in a flat tubular shape with an axial dimension smaller than its radial dimension. The coupled part 30 includes a cylindrical main body 30b and an inner flange 30a that protrudes radially inward from the upper end of the main body 30b. The inner peripheral edge of the inner flange 30a defines an opening 31 at the upper end of the coupled part 30. A pair of recesses 32 are formed on the outer peripheral surface of the main body 30b. The claws of the obturator 200 engage with the recesses 32, respectively, whereby the obturator 200 is attached to the gastrostomy catheter 100.

[0020] As shown in FIG. 2 and other figures, the gastrostomy catheter 100 further includes a check valve 40 provided at the upper end of the lumen 11. The check valve 40 is fitted into the inner cavity of the upper end of the lumen 11, for example. The check valve 40 has a valve port that opens and closes between an open state and a closed state. In the present embodiment, the check valve 40 is, for example, a duckbill valve. In the normal state, the valve opening of the check valve 40 is closed, blocking the opening at the upper end of the lumen 11. In this way, the check valve 40 prevents stomach contents from flowing back out of the body from the stomach. On the other hand, when nutrients or the like are injected into the stomach via the gastrostomy catheter 100, the valve opening is in an open state, connecting the lumen 11 to the outside of the body, thereby allowing the check valve 40 to pass nutrients from the outside of the body into the stomach.

[0021] The bumper 50 is formed, for example, in a substantially annular bag shape in a plan view, and is open, for example, upward. The bumper 50 is flexible and can be expanded in the radial direction. A portion of a wire (not shown) is arranged in a coiled manner inside the bumper 50. One end of the wire is introduced into the bumper 50 through the above-mentioned wire lumen 12 (see FIG. 2, etc.) formed in the shaft 10. As described above, before the gastrostomy catheter 100 is placed, the bumper 50 is folded and housed inside the capsule cover 70. When the capsule cover 70 is detached from the bumper 50 by the obturator 200, the bumper 50 expands radially due to the elastic restoring force of the wire and is locked to the stomach wall 520. When the wire inside the bumper 50 is removed from the bumper 50 from this state, the bumper 50 contracts radially and is released from the locking of the bumper 50 to the stomach wall 520. The outer surface of the bumper 50 is, for example, textured, which more reliably prevents the outer surfaces of the bumper 50 from sticking together when the bumper 50 is folded and housed in the capsule cover 70.

[0022] 5 and 7(a), the capsule cover 70 is formed, for example, in a cylindrical shape with a bottom and an axial direction extending in the vertical direction. The capsule cover 70 has, for example, a cylindrical mounting portion 72 that is mounted to the lower end of the shaft 10, and a tip closing portion 73 that closes the lower end of the mounting portion 72. The tip closing portion 73 is formed in a shape that bulges downward. In this embodiment, the restraining force of the tip closing portion 73 against the bumper 50 is greater than that of the mounting portion 72. The distal end closing portion 73 of the capsule cover 70 is formed with an insertion hole 74 through which a guide wire (not shown) is inserted vertically. The insertion hole 74, for example, passes vertically through the tip blocking portion 73. The axial center of the insertion hole 74, for example, coincides with the axial center of the mounting portion 72. The outer diameter of the insertion hole 74 is, for example, approximately constant regardless of the position in the axial direction.

[0023] 6, for example, the cross-sectional shape of the outer shape of the capsule cover 70 is polygonal (e.g., hexagonal), and the outer diameter thereof has a plurality of corners 75. On the other hand, the cross-sectional shape of the inner cavity of the capsule cover 70 is circular. In this embodiment, each corner 75 is formed continuously from the upper end of the capsule cover 70 to the vicinity of the insertion hole 74 . More specifically, the cross-sectional shape of the outer shape of the mounting portion 72 of the capsule cover 70 is hexagonal. Similarly, the cross-sectional shape of the outer shape of the distal end closing portion 73 of the capsule cover 70 is also hexagonal. However, the outer dimensions of the hexagonal shape of the distal end closing portion 73 gradually decrease downward. On the other hand, the outer dimensions of the hexagonal shape of the mounting portion 72 are approximately constant regardless of the axial position. The cross-sectional shape of the cavity of the attachment portion 72 of the capsule cover 70 is circular. Similarly, the cross-sectional shape of the cavity of the distal end closing portion 73 of the capsule cover 70 is also circular. However, the circular inner diameter of the distal end closing portion 73 gradually decreases downward. On the other hand, the circular inner diameter of the attachment portion 72 is approximately constant regardless of the position in the axial direction. In the present invention, the shape of the capsule cover 70 is not limited to this example, and for example, the outer cross section of the capsule cover 70 may be circular.

[0024] The material constituting the capsule cover 70 is not particularly limited, but examples thereof include edible cellulose-based or gelatin-based materials, and materials that are decomposed in the body, such as polylactic acid.

[0025] Here, in this embodiment, the surface roughness of the outer surface 70b of the lower part of the capsule cover 70 (in this embodiment, the tip closure portion 73) is smaller than the surface roughness of the outer surface 70b of the upper part of the capsule cover 70 (in this embodiment, the mounting portion 72). According to this configuration, when the lower end of the shaft 10 (and thus the capsule cover 70) is inserted into the lumen of the fistula 530, it is possible to suppress the frictional resistance (reduce the dynamic friction coefficient) of the lower part (tip occluding portion 73) of the capsule cover 70, which is inserted first into the fistula 530. Therefore, the lower end of the shaft 10 (capsule cover 70) can be smoothly inserted into the fistula 530. However, in the present invention, the surface roughness of the outer surface 70b of the lower part of the capsule cover 70 may be equal to the surface roughness of the outer surface 70b of the upper part of the capsule cover 70, or may be greater than the surface roughness of the outer surface 70b of the upper part. The frictional resistance (dynamic friction coefficient) referred to here may be the frictional resistance (dynamic friction coefficient) occurring between the inner surface of the fistula 530 and the lower part of the capsule cover 70, or the frictional resistance (dynamic friction coefficient) occurring between the inner surface of a gastrostomy sheath (not shown) inserted into the fistula 530 in advance and the lower part of the capsule cover 70.

[0026] In addition, in this embodiment, the inner diameter of the lower part of the capsule cover 70 (tip closure portion 73) decreases downward as described above, and it is preferable that the surface roughness of the inner surface 70a of the lower part of the capsule cover 70 (same as above) is smaller than the surface roughness of the inner surface 70a of the upper part of the capsule cover 70 (mounting portion 72). As described above, the restraining force on the bumper 50 is greater at the lower part of the capsule cover than at the upper part, but this configuration reduces frictional resistance between the inner surface 70a of the lower part and the bumper. Therefore, when placing the gastrostomy catheter 100, the capsule cover 70 can be smoothly detached from the bumper 50 using the insertion jig (obturator 200). However, in the present invention, the surface roughness of the inner surface 70a of the lower part of the capsule cover 70 may be equal to or greater than the surface roughness of the inner surface 70a of the upper part of the capsule cover 70.

[0027] Furthermore, as shown in Figures 7(a) and 7(b), the inner diameter of the upper end 71 of the capsule cover 70 expands upward, and the surface roughness of the inner surface 70a of the portion of the capsule cover 70 below the upper end 71 is smaller than the surface roughness of the inner surface 70a of the upper end 71. According to this configuration, the inner diameter of the upper end 71 of the capsule cover 70 expands upward, which allows for smooth insertion of the bumper 50 into the capsule cover 70. Furthermore, the surface roughness of the inner surface 70a of the portion of the capsule cover 70 below the upper end 71 (the portion including the mounting portion 72 and the tip closing portion 73 in this embodiment) is smaller than the surface roughness of the inner surface 70a of the upper end 71, which reduces frictional resistance between the inner surface 70a of the capsule cover 70 and the bumper 50, allowing for smooth removal of the bumper 50. However, in the present invention, the inner surface 70a of the portion of the capsule cover 70 below the upper end portion 71 may have a surface roughness equal to or greater than that of the inner surface 70a of the upper end portion 71. More specifically, in this embodiment, the upper end portion 71 of the capsule cover 70 has a first enlarged diameter portion 71a and a second enlarged diameter portion 71b, and is enlarged in diameter in two stages. The inner diameter of the first enlarged diameter portion 71a tapers upward from the upper end of the mounting portion 72. Similarly, the inner diameter of the second enlarged diameter portion 71b tapers upward from the upper end of the first enlarged diameter portion 71a. In a cross section along the axial direction of the capsule cover 70, the inclination angle R1 of the first expanded diameter portion 71a and the inclination angle R2 of the second expanded diameter portion 71b are different from each other. More specifically, in the example shown in Fig. 7(b), the inclination angle R1 of the upper end surface of the first expanded diameter portion 71a is larger than the inclination angle R2 of the upper end surface of the second expanded diameter portion 71b. However, the inclination angle R1 of the upper end surface of the first expanded diameter portion 71a may be smaller than the inclination angle R2 of the upper end surface of the second expanded diameter portion 71b. In this manner, in this embodiment, the upper end portion 71 of the capsule cover 70 is expanded in diameter in two stages with different amounts of change, so that the operation of inserting the bumper 50 into the capsule cover 70 can be performed more smoothly.

[0028] As described above, the capsule cover 70 according to this embodiment is a capsule cover 70 for a gastrostomy catheter 100 that includes a catheter main body 1 having a shaft 10 with a lumen 11 and a body surface contact portion 20, a bumper 50 that is provided at the lower end of the shaft 10 and expands within the stomach, and a capsule cover 70 that maintains the bumper 50 in a contracted state, and that detaches from the catheter main body when placed, causing the bumper 50 to expand, and the surface roughness of the inner surface 70a of the capsule cover 70 is smaller than the surface roughness of the outer surface 70b of the capsule cover 70. As described above, this configuration can suppress deformation of the capsule cover 70 when it is removed from the mold 600. Therefore, it is possible to provide a gastrostomy catheter equipped with a capsule cover 70 that is manufactured into a desired shape with good reproducibility.

[0029] More specifically, as shown in Figures 8(a) and 8(b), the outer surface 70b of the capsule cover 70 has a plurality of fine grooves 76 formed thereon, for example, extending along the axial direction of the capsule cover 70. On the other hand, for example, substantially no grooves 76 are formed on the inner surface 70a of the capsule cover 70. Alternatively, at least one of the number of grooves 76 formed on the inner surface 70a and the width of the grooves 76 is smaller than the number of grooves 76 formed on the outer surface 70b and the width of the grooves 76. More specifically, in the case of this embodiment, both the number of grooves 76 formed on the inner surface 70a and the width of the grooves 76 are smaller than the number of grooves 76 formed on the outer surface 70b and the width of the grooves 76, respectively. Furthermore, in addition to the groove portion 76 described above, a plurality of second groove portions 77 extending in a direction including a circumferential component of the capsule cover 70 are formed on the outer surface 70b of the upper portion (mounting portion 72) of the capsule cover 70. Some of the groove portions 76 and some of the second groove portions 77 intersect with each other. On the other hand, for example, substantially no second groove portions 77 are formed on the outer surface 70b of the lower portion (tip closing portion 73) of the capsule cover 70. Alternatively, at least one of the number of second groove portions 77 formed on the outer surface 70b of the lower portion of the capsule cover 70 and the width dimension of the second groove portions 77 is smaller than the number of second groove portions 77 formed on the outer surface 70b of the upper portion of the capsule cover 70 and the width dimension of the second groove portions 77. More specifically, in the case of this embodiment, both the number of second groove portions 77 formed on the outer surface 70b of the lower portion of the capsule cover 70 and the width dimension of the second groove portions 77 are smaller than the number of second groove portions 77 formed on the outer surface 70b of the upper portion of the capsule cover 70 and the width dimension of the second groove portions 77, respectively. With this configuration, the surface roughness of the outer surface 70b of the lower part (tip closing part 73) of the capsule cover 70 is smaller than the surface roughness of the outer surface 70b of the upper part (mounting part 72) of the capsule cover 70. 9, a plurality of recesses 71c are formed on the inner surface 70a of the upper end portion 71 of the capsule cover 70. Each of the plurality of recesses 71c has an irregular shape that protrudes in a plurality of directions different from one another. On the other hand, for example, substantially no recesses 71c are formed on the inner surface 70a of the capsule cover 70 in a portion below the upper end 71. Alternatively, at least one of the number of recesses 71c formed on the inner surface 70a of the capsule cover 70 below the upper end 71 or the outer diameter of the recesses 71c is smaller than the number of recesses 71c formed on the inner surface 70a of the upper end 71 of the capsule cover 70 or the outer diameter of the recesses 71c. More specifically, in this embodiment, both the number of recesses 71c formed on the inner surface 70a of the capsule cover 70 below the upper end 71 and the outer diameter of the recesses 71c are smaller than the number of recesses 71c formed on the inner surface 70a of the upper end 71 of the capsule cover 70 and the outer diameter of the recesses 71c, respectively. With this configuration, the surface roughness of the inner surface 70 a of the capsule cover 70 below the upper end portion 71 is smaller than the surface roughness of the inner surface 70 a of the upper end portion 71 . In the present embodiment, as an example, among the various parts of the capsule cover 70 described above, the surface roughness of each part increases in the following order: the inner surface 70a of the upper end 71 of the capsule cover 70, the outer surface 70b of the upper part of the capsule cover 70, the outer surface 70b of the lower part of the capsule cover 70, the inner surface 70a of the upper part of the capsule cover 70, and the inner surface 70a of the lower part of the capsule cover 70.

[0030] The method for forming the outer surface 70b of such a capsule cover 70 is not particularly limited, but one example is a method in which multiple grooves and irregularities (not shown) are formed on the inner surface of the recess 612 of the outer mold 610, and these grooves and irregularities are transferred to the outer surface 70b when the capsule cover 70 is molded. Similarly, the method for forming the inner surface 70a of the capsule cover 70 is not particularly limited, but one example is a method in which an inner mold 620 having a mirror-finished outer surface is used. According to this method, it is possible to realize a capsule cover 70 in which the surface roughness of the inner surface 70a is smaller than the surface roughness of the outer surface 70b. In the present invention, the method for achieving such surface roughness of each part of the capsule cover 70 is not limited to this example; for example, after molding the capsule cover 70, a polishing process may be further performed to achieve the above-mentioned magnitude relationship of the surface roughness of each part of the capsule cover 70.

[0031] Here, enlarged photographs of the inner surface 70a and outer surface 70b of the capsule cover 70 that was actually obtained are shown in Figs. 12(a) to 14. Figs. As shown in FIGS. 12(a) to 14, the surface roughness of the inner surface 70a of the capsule cover 70 in this embodiment is smaller than the surface roughness of the outer surface 70b of the capsule cover 70. As shown in Figures 12(a) and 12(b), in this embodiment, the surface roughness of the outer surface 70b of the lower part (tip closure portion 73) of the capsule cover 70 is smaller than the surface roughness of the outer surface 70b of the upper part (mounting portion 72) of the capsule cover 70. As shown in Figures 13(a) and 13(b), the surface roughness of the inner surface 70a of the lower part (tip closing part 73) of the capsule cover 70 is smaller than the surface roughness of the inner surface 70a of the upper part (mounting part 72) of the capsule cover 70. As shown in FIGS. 13(a) to 14, the surface roughness of the inner surface 70a of the capsule cover 70 below the upper end 71 is smaller than the surface roughness of the inner surface 70a of the upper end 71.

[0032] The obturator 200 will now be described in more detail. 3, the obturator 200 includes a tubular main body 210 extending vertically, and a connecting part 240 that is provided on the tubular main body 210 and detachably hooked onto a connected part 30 formed at the upper end of the body surface abutment part 20. The obturator 200 is attached to the gastrostomy catheter 100 by hooking the connecting part 240 onto the connected part 30. The tubular body 210 includes, for example, an outer tube portion 220 having a connecting portion 240 that is detachably connected to the upper end of the shaft 10, and an inner tube portion 230 that is inserted through the outer tube portion 220 so as to be slidable up and down. When the obturator 200 presses the capsule cover 70, the inner tube portion 230 is pressed downward relative to the outer tube portion 220. As a result, the lower end portion of the inner tube portion 230 presses the capsule cover 70 downward, the capsule cover 70 is detached from the bumper 50, and the bumper 50 is expanded.

[0033] 3 to 4(b), an example of a method of using the gastrostomy catheter 100 will be described. Note that the description will begin with a state in which a fistula 530, into which the gastrostomy catheter 100 is inserted, is formed by penetrating the abdominal wall 510 and the stomach wall 520, and the gastrostomy catheter 100 with an obturator 200 attached has been inserted into the fistula 530 in advance (see FIG. 3).

[0034] First, as shown in Figure 4(a), the inner tubular portion 230 of the obturator 200 is pushed downward relative to the outer tubular portion 220. As a result, the lower end of the inner tubular portion 230 presses the capsule cover 70 downward, the capsule cover 70 is detached from the bumper 50, and the bumper 50 is expanded. As a result, the bumper 50 is engaged with the stomach wall 520, and the gastrostomy catheter 100 is placed. Once the gastrostomy catheter 100 is placed, the connection of the obturator 200 to the connectable portion 30 is released, and the obturator 200 is removed from the gastrostomy catheter 100 (see Figure 4(b)). Furthermore, when removing the gastrostomy catheter 100 from the fistula 530, the wire is pulled out from the wire lumen 12 and therefore from the bumper 50. This causes the bumper 50 to contract radially, releasing the bumper 50 from its engagement with the stomach wall 520. This allows the gastrostomy catheter 100 to be removed from the stomach.

[0035] Here, as described above, in this embodiment, the surface roughness of the outer surface 70b of the lower part of the capsule cover 70 (in this embodiment, the tip closure portion 73) is smaller than the surface roughness of the outer surface 70b of the upper part of the capsule cover 70 (in this embodiment, the attachment portion 72). According to this configuration, when the lower end of the shaft 10 (and thus the capsule cover 70) is inserted into the lumen of the fistula 530, it is possible to suppress the frictional resistance of the lower part (tip closure portion 73) of the capsule cover 70, which is inserted first into the fistula 530. Therefore, the lower end of the shaft 10 (capsule cover 70) can be smoothly inserted into the fistula 530. Furthermore, as described above, in this embodiment, the inner diameter of the lower part (tip closure portion 73) of the capsule cover 70 decreases downward as described above, and it is preferable that the surface roughness of the inner surface 70a of the lower part (same as above) of the capsule cover 70 is smaller than the surface roughness of the inner surface 70a of the upper part (mounting portion 72) of the capsule cover 70. This configuration reduces frictional resistance between the bumper and the inner surface 70a of the lower part of the capsule cover 70. Therefore, when placing the gastrostomy catheter 100, the capsule cover 70 can be smoothly detached from the bumper 50 using the insertion tool (obturator 200).

[0036] The present invention is not limited to the above-described embodiments, and includes various modifications and improvements as long as the object of the present invention is achieved.

[0037] The present embodiment encompasses the following technical ideas. (1) A gastrostomy catheter comprising: a catheter body having a shaft with a lumen and a body surface contact portion; a bumper provided at the lower end of the shaft and expanding within the stomach; and a capsule cover that maintains the bumper in a contracted state; wherein the capsule cover detaches from the catheter body during placement, causing the bumper to expand; A gastrostomy catheter, wherein the surface roughness of the inner surface of the capsule cover is smaller than the surface roughness of the outer surface of the capsule cover. (2) The gastrostomy catheter according to (1), wherein the surface roughness of the outer surface of the lower part of the capsule cover is smaller than the surface roughness of the outer surface of the upper part of the capsule cover. (3) The lower portion of the capsule cover has an inner diameter that decreases downward, The gastrostomy catheter according to (1) or (2), wherein the surface roughness of the inner surface of the lower part of the capsule cover is smaller than the surface roughness of the inner surface of the upper part of the capsule cover. (4) The upper end of the capsule cover has an inner diameter that expands upward, The gastrostomy catheter according to (1) or (2), wherein the surface roughness of the inner surface of the capsule cover below the upper end portion is smaller than the surface roughness of the inner surface of the upper end portion. (5) A capsule cover for a gastrostomy catheter, comprising: a catheter body having a shaft with a lumen and a body surface contact portion; a bumper provided at the lower end of the shaft and expanding in the stomach; and a capsule cover for maintaining the bumper in a contracted state, wherein the capsule cover detaches from the catheter body and the bumper expands during placement, The surface roughness of the inner surface of the capsule cover is smaller than the surface roughness of the outer surface of the capsule cover. [Explanation of symbols]

[0038] 1. Catheter body 10 shaft 11 lumens 12 wire lumens 20 Body surface contact part 30 Connected part 30a Inner flange 30b Main body 31 Aperture 32 recess 40 Check valve 50 Bumper 70 Capsule Cover 70a inner surface 70b outer surface 71 Upper end 71a 1st enlarged diameter section 71b 2nd enlarged diameter section 71c Recess 72 Mounting part (top of capsule cover) 73 Tip occlusion part (bottom of capsule cover) 74 Insertion hole 75 Corner 76 Groove 77 Second groove 80 Plug member 100 Gastrostomy catheter 200 Obturator 210 Tubular body 220 Outer pipe section 230 Inner pipe section 240 Connection section 510 Abdominal wall 520 Stomach wall 530 Fistula 600 molds 610 External mold 612 recess 614 Cavity 620 Inner mold

Claims

1. A gastrostomy catheter comprising: a catheter body having a shaft with a lumen and a body surface abutment portion; a bumper provided at the lower end of the shaft and expanding within the stomach; and a capsule cover for maintaining the bumper in a contracted state, wherein the capsule cover detaches from the catheter body during placement, causing the bumper to expand; A gastrostomy catheter, wherein the surface roughness of the inner surface of the capsule cover is smaller than the surface roughness of the outer surface of the capsule cover.

2. The gastrostomy catheter according to claim 1, wherein the surface roughness of the outer surface of the lower part of the capsule cover is smaller than the surface roughness of the outer surface of the upper part of the capsule cover.

3. The lower portion of the capsule cover has an inner diameter that decreases downward, 3. The gastrostomy catheter according to claim 1, wherein the surface roughness of the inner surface of the lower part of the capsule cover is smaller than the surface roughness of the inner surface of the upper part of the capsule cover.

4. The upper end of the capsule cover has an inner diameter that expands upward, 3. The gastrostomy catheter according to claim 1, wherein the surface roughness of the inner surface of the capsule cover below the upper end is smaller than the surface roughness of the inner surface of the upper end.

5. A capsule cover for a gastrostomy catheter comprising: a catheter body having a shaft with a lumen and a body surface abutment portion; a bumper provided at the lower end of the shaft and expanding within the stomach; and a capsule cover for maintaining the bumper in a contracted state, wherein the capsule cover detaches from the catheter body and the bumper expands during placement, The surface roughness of the inner surface of the capsule cover is smaller than the surface roughness of the outer surface of the capsule cover.

Images