Gastrostomy catheter

Abstract

To provide a gastrostomy catheter capable of more surely regulating the backflow of a nutrient or gastric contents from the inside of the stomach to the outside of the body.SOLUTION: The gastrostomy catheter 100 comprises a shaft 10 having a lumen 11, and a check-valve 40, wherein the check-valve 40 has a base part 41, a downward projecting part 51, and an annular 51a part 43, the shaft 10 has a body surface contact part 20 and an annular rib 23, the gap between the annular wall part 43 and the downward projecting part 51 constitutes an annular groove 44 into which the annular rib 23 fits, and a valve opening 45 is formed in the side wall of the lower end of the downward projecting part 51. A lower portion of the downward projecting portion 51 serves as a press-fitting portion 53, the press-fitting portion 53 has a large-diameter portion 54 whose size in the first direction is larger than the inside diameter of the lumen 11, and the size of the downward projecting portion 51 in the first direction gradually increases downward at a boundary portion 54a between the upper portion 52 of the downward projecting portion 51 and the large-diameter portion 54.SELECTED DRAWING: Figure 2

Description

[Technical Field]

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

[0002] An example of a gastrostomy catheter is described in Patent Document 1. The gastrostomy catheter in Patent Document 1 (referred to as a valve assembly in the document) comprises a shaft with a lumen and a check valve (referred to as a valve member in the document), and the check valve comprises a hollow section including a pair of elastically deformable beak-shaped portions, and a valve opening that opens and closes between a closed state and an open state, with the valve opening opening being opened when each of the pair of beak-shaped portions elastically deforms, and closing when each of the pair of beak-shaped portions elastically restores its original state. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2004-516076 Summary of the Invention [Problem to be solved by the invention]

[0004] According to the investigations of the present inventors, there is still room for improvement in the gastrostomy catheter of Cited Document 1 in terms of more reliably preventing nutrients and stomach contents from flowing back out of the stomach to the outside of the body.

[0005] The present invention has been made in view of the above-mentioned problems, and provides a gastrostomy catheter having a structure that can more reliably prevent nutrients and stomach contents from flowing back out of the body from the stomach. [Means for solving the problem]

[0006] According to the present invention, there is provided a gastrostomy catheter comprising a shaft having a lumen and an anti-reflux valve, The check valve is a plate-shaped base portion disposed to cover the upper end of the shaft; a downward protrusion protruding downward from a central portion of the base; an annular wall portion that rises downward from the peripheral edge of the base portion and surrounds the periphery of the upper end portion of the downward protrusion; and The shaft A body surface contact portion; an annular rib formed along the peripheral edge of the upper end opening of the lumen and standing upward from the body surface abutment portion; and a gap between an inner peripheral surface of the annular wall portion and an outer peripheral surface of an upper end portion of the downward protrusion portion forms an annular groove into which the annular rib is fitted, A slit-shaped valve opening that opens and closes between a closed state and an open state is formed at the lower end of the downward protrusion, A lower portion of the downward protrusion is a press-fit portion that is press-fitted into the upper end portion of the lumen, the press-fit portion has a large diameter portion whose dimension in a first direction, which is a direction perpendicular to at least both the longitudinal direction of the valve orifice and the axial direction of the shaft, is larger than the inner diameter of the lumen; The gastrostomy catheter is provided in which the dimension of the downward protrusion in the first direction gradually increases downward at the boundary between the upper portion of the downward protrusion and the large diameter portion. [Effects of the Invention]

[0007] According to the present invention, it is possible to more reliably prevent nutrients and stomach contents from flowing back out of the body from the stomach. [Brief explanation of the drawings]

[0008] [Figure 1] FIG. 1 is a perspective view of a gastrostomy catheter according to a first embodiment. [Figure 2] FIG. 1 is a longitudinal cross-sectional view of a gastrostomy catheter according to a first embodiment. [Figure 3] FIG. 2 is a perspective view of the check valve according to the first embodiment. [Figure 4]FIG. 2 is a bottom view of the check valve according to the first embodiment. [Figure 5] FIG. 2 is a side view of the check valve according to the first embodiment. [Figure 6] FIG. 5 is a cross-sectional view taken along line BB shown in FIG. [Figure 7] FIG. 5 is a cross-sectional view taken along the line AA shown in FIG. [Figure 8] FIG. 2 is a bottom view of the check valve according to the first embodiment, showing the state in which the valve port is open. [Figure 9] FIG. 10 is a perspective view of a check valve according to a second embodiment. [Figure 10] FIG. 10 is a bottom view of the check valve according to the second embodiment. [Figure 11] FIG. 10 is a side view of a check valve according to a second embodiment. [Figure 12] FIG. 11 is a cross-sectional view taken along the line AA shown in FIG. [Figure 13] FIG. 10 is a bottom view of the check valve according to the second embodiment, showing the valve port in an open state. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present invention will be described with reference to the drawings. In all the drawings, the same components are denoted by the same reference numerals, and the description thereof will be omitted where appropriate.

[0010] [First embodiment] First, the first embodiment will be described with reference to Figures 1 to 8. Figure 2 is a cross-sectional view of the shaft 10 taken along the axial direction. 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 FIG. 2, the gastrostomy catheter 100 according to this embodiment includes a shaft 10 having a lumen 11 and an anti-reflux valve 40. The check valve 40 has a plate-shaped base 41 that is arranged to cover the upper end of the shaft 10, a downward protrusion 51 that protrudes downward from the center of the base 41, and an annular wall 43 that stands downward from the peripheral edge of the base 41 and surrounds the upper end of the downward protrusion 51. The shaft 10 has a body surface contact portion 20 and an annular rib 23 formed along the peripheral edge of the upper end opening 11a of the lumen 11 and standing upward from the body surface contact portion 20. The gap between the inner peripheral surface of the annular wall portion 43 and the outer peripheral surface of the upper end portion of the downward protrusion 51 forms an annular groove 44 into which the annular rib 23 fits. A slit-like valve opening 45 that opens and closes between a closed state and an open state is formed at the lower end 51a of the downward protruding portion 51. The lower part of the downward protrusion 51 is a press-fit portion 53 that is press-fitted into the upper end of the lumen 11, and the press-fit portion 53 has a large diameter portion 54 whose dimension in a first direction (e.g., Y direction shown in FIG. 4), which is a direction perpendicular to both the longitudinal direction of the valve orifice 45 (e.g., X direction (hereinafter, second direction) shown in FIG. 4) and the axial direction of the shaft 10, is larger than the inner diameter of the lumen 11. At a boundary 54a between the upper portion 52 of the downward protruding portion 51 and the large diameter portion 54, the dimension of the downward protruding portion 51 in the first direction gradually increases downward. Here, "the dimension in the first direction is larger than the inner diameter of the lumen 11" means that when the check valve 40 is removed from the shaft 10, the dimension of the large diameter portion 54 in the first direction is larger than the inner diameter of the lumen 11. Then, as shown in Fig. 2, when the large diameter portion 54 is press-fitted into the shaft 10, it is pressed against the tube wall of the shaft 10, reducing the outer diameter of the large diameter portion 54.

[0012] The check valve 40 allows the fluid to flow in one direction (hereinafter referred to as the first flow direction), while restricting the fluid from flowing in the opposite direction (hereinafter referred to as the second flow direction). In the present embodiment, as an example, the downward direction in FIG. 2 is the first flow direction, and the upward direction in FIG. 2 is the second flow direction. When the valve port 45 opens in the first direction (is in an open state), the flow of fluid in the first flow direction is permitted, and when the valve port 45 closes in the first direction (is in a closed state), the flow of fluid in the second flow direction is restricted. With the lower end of the shaft 10 of the gastrostomy catheter 100 placed in the stomach, a bumper 60 (described later) is expanded, causing the bumper 60 to engage with the stomach wall and leave the gastrostomy catheter 100 in place. In this state, the gastrostomy catheter 100 communicates between the inside of the stomach and the outside of the living body, and liquids such as nutrients are injected into the stomach through the gastrostomy catheter 100. When a nutrient or other substance is injected into the stomach via the gastrostomy catheter 100, the valve opening 45 opens, connecting the lumen 11 to the outside of the body. This allows fluid to flow in the first flow direction, allowing the nutrient to pass from the outside of the body into the stomach. When the injection of the nutrient or other substance into the stomach is completed, the valve opening 45 closes, blocking the upper end opening 11a of the shaft 10. This restricts the flow of fluid in the second flow direction, preventing stomach contents from flowing back out of the body.

[0013] According to this embodiment, the press-fit portion 53 that is press-fitted into the upper end portion of the lumen 11 has a large diameter portion 54 whose dimension in the first direction is larger than the inner diameter of the lumen 11. As a result, the press-fit portion 53 is configured to be pressed inward from both sides in the first direction by the inner walls of the shaft 10. That is, the press-fit portion 53 is configured to be pressed in the first direction by the inner walls of the shaft 10 in a direction that closes the valve orifice 45. This makes it possible to more reliably switch the valve port 45 from the open state to the closed state, thereby more reliably restricting the flow direction of the fluid to one direction. The shaft 10 also has an annular rib 23 that is fitted into the annular groove 44 . This prevents nutrients and stomach contents from flowing back toward the upper end opening 11a of the shaft 10 through the gap between the inner surface 11b of the lumen 11 and the outer surface of the check valve 40. Furthermore, in this embodiment, at a boundary portion 54a between the upper portion 52 of the downward protruding portion 51 and the large diameter portion 54, the dimension of the downward protruding portion 51 in the first direction gradually increases downward. This allows the annular rib 23 to be smoothly guided into the annular groove 44, so that the annular rib 23 can be fitted into the annular groove 44 satisfactorily. In this way, according to this embodiment, it is possible to more reliably prevent nutrients and stomach contents from flowing back out of the stomach to the outside of the body.

[0014] In this embodiment, the inner cavity of the shaft 10 forms a lumen 11 . 2 and 3, 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 connected part 30 (described later) is attached to the upper end of the shaft 10, and a bumper 60 (described later) is provided to the lower 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 the other parts of the lumen 11, and forms a housing portion 12 in which the check valve 40 is housed. The inner diameter of the housing portion 12 is approximately constant regardless of the position in the axial direction. As shown in FIG. 2, the press-fit portion 53 of the check valve 40 is press-fitted into the housing portion 12. As described above, the annular rib 23 is formed on the peripheral edge of the upper end opening 11a of the lumen 11. The annular rib 23 is formed circumferentially along the peripheral edge of the upper end opening 11a. As shown in Fig. 2, the upper end of the annular rib 23 is, for example, a flat surface facing upward.

[0015] The body surface abutment portion 20 is a portion exposed to the body surface of the user when the gastrostomy catheter 100 is indwelling, and the underside of the body surface abutment portion 20 faces the outer surface of the abdominal wall. As shown in Fig. 1, the body surface abutment portion 20 includes, for example, a first overhanging portion 21a that overhangs in one radial direction from the outer circumferential surface of the upper end of the shaft 10, and a second overhanging portion 21b that overhangs in the other radial direction from the outer circumferential surface. The undersides of the first overhanging portion 21a and the second overhanging portion 21b are each formed flat. The second protruding portion 21b is provided with, for example, a plug member 80 (see FIG. 1) that can be inserted into the upper end of the check valve 40 to close the check valve 40 from the external space above. The plug member 80 extends, for example, from the end of the second protruding portion 21b opposite to the shaft 10 side toward the outside in the radial direction. More specifically, the plug member 80 includes, for example, a strap portion 84 extending along the protruding direction of the second protruding portion 21b, and a plug portion 82 formed at the end of the strap portion 84 opposite the shaft 10 side. The strap portion 84 is formed, for example, in the shape of a flat plate piece, and is elastically deformable in a direction curving upward and radially inward. The plug portion 82 is formed, for example, in a cylindrical shape that protrudes upward from the upper surface of the strap portion 84. A flange portion 82a is formed at the upper end of the plug portion 82, protruding radially outward from the upper end. The strap portion 84 elastically deforms into a shape curved upward and radially inward, and the plug portion 82 is inserted into the upper end portion of the check valve 40. This makes it possible to close the check valve 40 from the external space above.

[0016] As described above, the check valve 40 has the base 41 , the downward protrusion 51 , the annular wall 43 , and the valve port 45 . The base 41 is formed, for example, in a circular ring shape in a plan view. The base 41 is formed, for example, in a flat plate shape, and the plate surface faces in the vertical direction. 2, the outer diameter of the base 41 is set to a dimension larger than the outer diameter of the upper end of the shaft 10, for example, and the base 41 is engaged with the upper end of the shaft 10. The connected part 30 is disposed on the upper surface of the base 41. The downward protrusion 51 is formed, for example, in a cylindrical shape with its axis extending in the vertical direction. The downward protrusion 51 protrudes downward from the inner peripheral edge of the base 41. The downward protruding portion 51 has an inner peripheral surface formed with a circumferential groove 41a into which a flange portion 82a of the plug portion 82 is engaged. The inner diameter of the downward protrusion 51 in the second direction is generally constant regardless of the axial position, except for the region where the groove 41a is formed, while the inner diameter of the downward protrusion 51 in the first direction gradually decreases downward, for example. In this embodiment, as described above, the lower part of the downward protruding part 51 serves as a press-fit part 53 that is press-fitted into the upper end part of the lumen. The large diameter portion 54 of the press-fit portion 53 is formed, for example, in a cylindrical shape with its axial direction extending in the vertical direction. The outer diameter of the large diameter portion 54 is substantially constant regardless of its position in the axial direction. The outer diameter of the large diameter portion 54 is set to be larger than the outer diameter of the upper portion 52 of the downward protruding portion 51. The outer diameter of a boundary portion 54a between the upper portion 52 of the downward protruding portion 51 and the large diameter portion 54 gradually decreases upward. As shown in FIGS. 5 and 6 , there is no step at the boundary between the upper portion 52 of the downward protruding portion 51 and the boundary portion 54a, and at the boundary between the boundary portion 54a and the large diameter portion 54. More specifically, the outer diameter of the lower end of the boundary portion 54a is set to be equal to the outer diameter of the large diameter portion 54, and the outer diameter of the upper end of the boundary portion 54a is set to be equal to the outer diameter of the upper portion 52 of the downward protruding portion 51. This allows the press-fit portion 53 to be smoothly press-fitted into the accommodating portion 12 of the lumen 11. The annular wall portion 43 is formed, for example, in a circular ring shape in a plan view. The annular wall portion 43 protrudes downward from the outer peripheral edge of the base portion 41. The inner diameter and the outer diameter of the annular wall portion 43 are each substantially constant regardless of the position in the axial direction. The annular groove 44 is defined by the lower surface of the base portion 41, the outer peripheral surface of the downward protrusion 51, and the inner peripheral surface of the annular wall portion 43. The annular groove 44 is formed in a circular ring shape in a plan view. The check valve 40 also has a second annular wall portion 47 that stands upward from the inner circumferential edge of the base portion 41. The second annular wall portion 47 is fitted into the connected portion 30. In this embodiment, the valve opening 45 is formed, for example, on the lower end surface of the large diameter portion 54. The valve opening 45 is, for example, a slit extending in a direction perpendicular to both the first direction and the axial direction of the shaft 10. In the open state, the valve opening 45 (slit) connects the inner cavity of the check valve and the lumen 11, and in the closed state, it blocks this communication.

[0017] In the case of this embodiment, as shown in FIG. 2, in the check valve 40, the upper portion 52 of the downward protruding portion 51 and the press-fit portion 53 are press-fitted into the accommodation portion 12. More specifically, the outer diameter of the upper portion 52 of the downward protrusion 51 is set to be approximately equal to the inner diameter of the accommodating portion 12. On the other hand, the outer diameter of the press-fit portion 53 is set to be larger than the inner diameter of the accommodating portion 12. Because the large diameter portion 54 is press-fitted into the accommodating portion 12, the portion of the accommodating portion 12 that corresponds to the large diameter portion 54 is slightly expanded radially outward. As described above, the large diameter portion 54 is formed in a cylindrical shape, and the outer peripheral surface of the large diameter portion 54 and the inner peripheral surface of the accommodating portion 12 are in surface contact in a circumferential manner. This prevents nutrients and stomach contents from flowing back toward the upper end opening 11a of the lumen 11 through the gap between the outer circumferential surface of the large diameter portion 54 and the inner circumferential surface of the storage portion 12. The annular rib 23 of the shaft 10 is press-fitted into the annular groove 44. More specifically, the inner peripheral surface of the annular rib 23 is in surface contact with the outer peripheral surface of the upper part 52 of the downward protrusion 51, and the outer peripheral surface of the annular rib 23 is in surface contact with the inner peripheral surface of the annular wall portion 43. In this embodiment, a small gap is formed between the upper end surface of the annular rib 23 and the lower surface of the annular groove 44, and this gap is filled with an adhesive (not shown) in a circumferential manner, thereby joining the annular groove 44 and the annular rib 23 in a liquid-tight (air-tight) manner. This configuration can prevent nutrients and stomach contents from leaking from the upper end opening 11a of the lumen 11 into the space outside the gastrostomy catheter 100 through the gap between the annular groove 44 and the annular rib 23.

[0018] In this embodiment, the annular wall portion 43 is formed with, for example, a notch-shaped portion 46 that allows the annular groove 44 and the space around the outer periphery of the annular wall portion 43 to communicate with each other. This allows the adhesive to overflow from the cutout portions 46 after the adhesive has spread throughout the annular groove 44 when the annular rib 23 is press-fitted into the annular groove 44 filled with adhesive. Therefore, it is easy to visually confirm that the adhesive has been filled circumferentially into the annular groove 44, and liquid-tightness (air-tightness) between the annular groove 44 and the annular rib 23 can be more reliably ensured.

[0019] In this embodiment, the lower end 52 b of the upper portion 52 of the downward protruding portion 51 is located lower than the lower end 43 a of the annular wall portion 43 . This allows the annular rib 23 to be guided more smoothly into the annular groove 44 when the downward protrusion 51 is press-fitted into the accommodating portion 12 . However, for example, the position of the lower end 52b of the upper portion 52 of the downward protruding portion 51 and the position of the lower end 43a of the annular wall portion 43 may be the same in the vertical direction.

[0020] 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. An insertion tool for a gastrostomy catheter (not shown) (hereinafter referred to as "insertion tool") or a connecting connector (not shown) is selectively and detachably hooked onto the connecting part 30. This allows the insertion tool or connecting connector to be attached to the gastrostomy catheter 100. The connected part 30 is formed, for example, in a flat cylindrical shape with an axial dimension smaller than its radial dimension. The second annular wall part 47 of the check valve 40 is fitted into the opening 31 on the upper end side of the connected part 30. In this way, the connected part 30 is attached to the check valve 40. A pair of recesses 32 are formed on the outer circumferential surface of the connected portion 30. The claws (not shown) of the insertion jig engage with the recesses 32, respectively, thereby attaching the insertion jig to the gastrostomy catheter 100. Similarly, the claws (not shown) of the connecting connector engage with the corresponding recesses 32, respectively, thereby attaching the connecting connector to the gastrostomy catheter 100.

[0021] In this embodiment, the check valve 40 is, for example, elastically deformable. 8, when a nutrient solution or the like is injected into the stomach via the gastrostomy catheter 100, the valve opening 45 is pressed by the nutrient solution and expanded outward in the first direction, elastically deforming into an open shape, thereby changing the valve opening 45 from a closed state to an open state. When the injection of nutrients or the like is completed, the valve opening 45 narrows inward in the first direction and then elastically restores to a closed shape, as shown in Figure 4. More specifically, the inner circumferential surfaces of the peripheral edges of the valve opening 45 approach or adhere to each other at the lower end of the downward protrusion 51. This causes the valve opening 45 to change from an open state to a closed state. As described above, the large diameter portion 54 in which the valve orifice 45 is formed has a dimension in the first direction larger than the inner diameter of the storage portion 12 (the upper end of the lumen 11), and is press-fit into the storage portion 12. Therefore, the large diameter portion 54 is pressed inward in the first direction by the inner circumferential surface 11b of the shaft 10. As a result, the pressing force from the inner circumferential surface 11b of the shaft 10 assists the valve orifice 45 in elastically restoring itself to a closed shape. This makes it possible to more reliably switch the valve orifice 45 from an open state to a closed state.

[0022] 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.

[0023] The check valve 40 is integrally formed from, for example, an elastic material. The elastic material is not particularly limited, but examples thereof include silicone rubber and elastomer.

[0024] The bumper 60 is fixed to the lower end of the shaft 10. The bumper 60 is formed in, for example, a substantially annular bag shape in a plan view, and is open, for example, upward. The bumper 60 is flexible and can expand in the radial direction. A portion of a wire (not shown) is arranged in a coiled manner inside the bumper 60. One end of the wire is introduced into the bumper 60 through a wire lumen (not shown) formed in the shaft 10. Before the gastrostomy catheter 100 is placed, the bumper 60 is folded and housed inside a capsule cover (not shown). When the capsule cover is detached from the bumper 60 by an insertion tool, the bumper 60 expands radially due to the elastic restoring force of the wire and is anchored to the stomach wall. When the wire inside the bumper 60 is removed from the bumper 60 from this state, the bumper 60 contracts radially and is released from the stomach wall.

[0025] Second Embodiment Next, a second embodiment will be described with reference to Figures 9 to 13. The check valve 40 in this embodiment differs from the check valve 40 in the first embodiment described above in the points described below, but is otherwise configured similarly to the check valve 40 in the first embodiment described above. Note that in this embodiment, a vertical cross-sectional view of the check valve 40 press-fitted into the upper end of the lumen 11 is omitted because it is the same as Figure 2 of the first embodiment.

[0026] 9, in this embodiment, the downward protruding portion 51 has a main body 55 including a pair of beak-shaped portions 56, 57. The joint between the lower ends of the pair of beak-shaped portions 56 (in this embodiment, the tips of the tips 56a, 57a) forms the valve orifice 45. The large diameter portion 54 has a pair of plate-like portions 58, 59 that stand upright from the main body portion 55 in both directions in the first direction. Even with this configuration, the press-fit portion 53 is pressed in the first direction by the inner wall of the shaft 10 in the direction that closes the valve port 45. This ensures that the valve port 45 can be switched from the open state to the closed state more reliably. This makes it possible to more reliably restrict the flow direction of the fluid to one direction.

[0027] The main body 55 is formed, for example, in a hollow shape. More specifically, the main body 55 has a second press-fit portion 55a that is press-fitted into the upper end of the lumen 11. The second press-fit portion 55a is formed in a generally annular shape in a plan view. Each of the pair of beak-shaped portions 56 protrudes downward from, for example, the inner circumferential edge of the second press-fit portion 55a. In this embodiment, the second press-fit portion 55a forms the upper end portion of the downward protrusion 51. Therefore, the annular groove 44 is a gap between the outer peripheral surface of the second press-fit portion 55a and the inner peripheral surface of the annular wall portion 43. The outer diameter of the second press-fit portion 55a is set to be approximately equal to the inner diameter of the accommodating portion 12, for example, and the second press-fit portion 55a is press-fitted into the accommodating portion 12. The second press-fit portion 55a is formed, for example, in a circular ring shape in a plan view. The second press-fit portion 55a protrudes downward from the inner peripheral edge of the base 41. The lower surface of the second press-fit portion 55a is formed flat and is disposed horizontally. As shown in Figures 11 and 12, the inner diameter of the main body 55 in the first direction gradually decreases downward, while the inner diameter in the second direction is approximately constant regardless of the position in the axial direction.

[0028] Each of the pair of beak-shaped portions 56, 57 protrudes downward from the inner peripheral edge of the second press-fit portion 55a, for example. In this embodiment, the joint between the tip ends 56a, 57a of the pair of beak-shaped portions 56, 57 forms the valve orifice 45. The tip ends 56a, 57a extend along the second direction and are in close contact with or close to each other. The side shape of each beak-shaped portion 56, 57 when viewed in the second direction (Y direction shown in Figure 10) (see the shape of beak-shaped portion 56 shown in Figure 12) is approximately crescent-shaped with the chord located at the bottom and the arc located at the top. In each of the beak-shaped portions 56, 57, the intermediate portions 56c, 57c connecting the arcuate upper edge portions 56b, 57b and the tip portions 56a, 57a are, for example, flat, although the intermediate portions 56c, 57c may also be curved. In addition, in each beak-shaped portion 56, 57, the portions 56d, 57d other than the flat-plate-shaped intermediate portions 56c, 57c have a convex curved shape extending radially outward, and extend from the arc-shaped upper edge portions 56b, 57b to both ends of the tip portions 56a, 57a. Each of the intermediate portions 56c, 57c is inclined downward, for example, from the outside (the side opposite the axial center of the downward protruding portion 51) to the inside (the axial center of the downward protruding portion 51) in the first direction. The tip portions 56a, 57a are connected to each other at a portion of their tips to form a joint (valve opening 45). In a plan view, each of the tip portions 56a, 57a extends in the second direction. The tip portions 56a, 57a of the pair of beak-shaped portions 56, 57 are connected to each other at one end and the other end in the second direction. On the other hand, the tip portions are not connected to each other at an intermediate portion in the second direction, and this not-connected portion forms the valve opening 45. The tip surface (lower end surface) of the tip portion 56a of one of the pair of beak-shaped portions 56, 57 is, for example, flat and disposed horizontally. Similarly, the tip surface (lower end surface) of the tip portion 57a ​​of the other of the pair of beak-shaped portions 56, 57 is, for example, flat and disposed horizontally.

[0029] One plate-shaped portion 58 of the pair of plate-shaped portions 58, 59 protrudes outward in the first direction from the outer peripheral surface of one beak-shaped portion 56 of the pair of beak-shaped portions 56, 57, and the other plate-shaped portion 59 protrudes outward in the first direction from the outer peripheral surface of the other beak-shaped portion 57. The inner edges of each of the pair of plate-shaped portions 58, 59 are arranged, for example, along the outer peripheral surface of the corresponding beak-shaped portion 56 and slope downward from the outside to the inside in the first direction. On the other hand, the outer edges of each of the pair of plate-shaped portions 58, 59 extend along the axial direction. Therefore, the dimension of each of the pair of plate-shaped portions 58, 59 in the first direction gradually increases downward.

[0030] In the axial direction, the height position of the upper end of each of the pair of plate-like portions 58, 59 is set to be equal to the height position of the upper end of each of the pair of beak-like portions 56, 57. The plate surfaces of the pair of plate-shaped portions 58, 59 are arranged facing the second direction (the longitudinal direction of the valve port 45). In this embodiment, the large diameter portion 54 of the downward protrusion 51 is formed by the portion between the outer edge of one of the pair of plate-shaped portions 58, 59 and the outer edge of the other plate-shaped portion 59. More specifically, in the first direction, the outer edge of each of the pair of plate-shaped portions 58, 59 protrudes outward beyond the outer peripheral surface of the second press-fit portion 55a. A separation distance D1 (see FIG. 11) between the outer edge of one of the pair of plate-shaped portions 58 and the outer edge of the other plate-shaped portion 59 in the first direction is the dimension of the large diameter portion 54 in the first direction. Therefore, separation distance D1 is greater than both the outer diameter of the second press-fit portion 55a and the inner diameter of the accommodation portion 12. In this embodiment, the dimension of the downward protruding portion 51 in the first direction gradually increases downward at boundaries 58b, 59b between the second press-fit portion 55a and the plate-like portions 58, 59. Furthermore, no steps are formed at the boundaries between the second press-fit portion 55a and the boundaries 58b, 59b, and at the boundaries between the boundaries 58b, 59b and each of the plate-like portions 58, 59. This allows the annular rib 23 to be smoothly guided into the annular groove 44, similar to the first embodiment. The boundaries 58b and 59b are, for example, plate-like portions having the same thickness as the thickness of the plate-like portions 58 and 59. The plate surfaces of the boundaries 58b and 59b are arranged facing the second direction. Also in this embodiment, the lower end 52b of the upper portion 52 of the downward protruding portion 51 (the lower end of the second press-fit portion 55a) is located lower than the lower end 43a of the annular wall portion 43. This allows the annular rib 23 to be guided more smoothly into the annular groove 44 when the downward protrusion 51 is press-fitted into the accommodating portion 12 . However, for example, the position of the lower end 52b of the upper portion 52 of the downward protruding portion 51 and the position of the lower end 43a of the annular wall portion 43 may be the same in the vertical direction.

[0031] In this embodiment, the valve opening 45 opens as a result of elastic deformation of each of the pair of beak-shaped portions 56, 57, allowing the fluid to flow in the first flow direction. From this state, the valve opening 45 closes as each of the pair of beak-shaped portions 56, 57 elastically restores its original shape, restricting the fluid from flowing in the second flow direction. More specifically, when a fluid flows in the first flow direction, the tip ends 56 a, 57 a of the pair of beak-shaped portions 56, 57 are pressed by the fluid and elastically deform into a shape spaced apart from each other in the first direction, as shown in FIG. 13 . More specifically, the tip end 56 a of the beak-shaped portion 56 elastically deforms into a convex arc shape toward the side opposite the tip end 57 a in the first direction (e.g., downward in FIG. 13 ), and the tip end 57 a of the beak-shaped portion 57 elastically deforms into a convex arc shape toward the side opposite the tip end 56 a in the first direction (e.g., upward in FIG. 13 ). This opens the valve orifice 45, allowing the flow of fluid in the first flow direction. Then, when the flow of the fluid stops, the tip ends 56 a, 57 a of the pair of beak-shaped portions 56, 57 elastically restore to a shape in which they are close to or in close contact with each other in the first direction. More specifically, the tip ends 56a, 57a of the pair of beak-shaped portions 56, 57 elastically restore to a shape extending linearly along the second direction, thereby closing the valve opening 45 and restricting the flow of fluid in the second flow direction (i.e., backflow of fluid).

[0032] The present invention is not limited to the above-described embodiments, but includes various modifications and improvements as long as the object of the present invention is achieved.

[0033] The present embodiment encompasses the following technical ideas. (1) A gastrostomy catheter comprising a shaft having a lumen and an anti-reflux valve, The check valve is a plate-shaped base portion disposed to cover the upper end of the shaft; a downward protrusion protruding downward from a central portion of the base; an annular wall portion that rises downward from the peripheral edge of the base portion and surrounds the periphery of the upper end portion of the downward protrusion; and The shaft A body surface contact portion; an annular rib formed along the peripheral edge of the upper end opening of the lumen and standing upward from the body surface abutment portion; and a gap between an inner peripheral surface of the annular wall portion and an outer peripheral surface of an upper end portion of the downward protrusion portion forms an annular groove into which the annular rib is fitted, A slit-shaped valve opening that opens and closes between a closed state and an open state is formed at the lower end of the downward protrusion, A lower portion of the downward protrusion is a press-fit portion that is press-fitted into the upper end portion of the lumen, the press-fit portion has a large diameter portion whose dimension in a first direction, which is a direction perpendicular to at least both the longitudinal direction of the valve orifice and the axial direction of the shaft, is larger than the inner diameter of the lumen; A gastrostomy catheter in which the dimension of the downward protruding portion in the first direction gradually increases downward at the boundary between the upper portion of the downward protruding portion and the large diameter portion. (2) The gastrostomy catheter according to (1), wherein the lower end of the upper part of the downward protrusion is located lower than the lower end of the annular wall portion. (3) The gastrostomy catheter according to (1) or (2), wherein the large diameter portion is formed in a cylindrical shape. (4) The downward protrusion has a main body including a pair of beak-shaped portions, The joint between the lower ends of the pair of beak-shaped portions forms the valve opening, The gastrostomy catheter according to (1) or (2), wherein the large diameter portion has a pair of plate-like portions standing upright in both directions in the first direction from the main body portion. (5) A gastrostomy catheter according to any one of (1) to (4), wherein the annular wall portion has a notch-shaped portion formed therein that connects the annular groove to the space around the annular wall portion. [Explanation of symbols]

[0034] 10 shaft 10a pipe wall 11 lumens 11a Top opening 11b Inner surface 12 Storage section 20 Body surface contact part 21a 1st overhang 21b 2nd overhang 23 Annular rib 30 Connected part 31 Aperture 32 recess 40 Check valve 41 Base 41a Groove 43 Annular wall 43a bottom end 44 Annular groove 45 Valve Orifice 46 Notched portion 47 Second annular wall 51 Downward protrusion 51a Bottom end 52 Upper 52a Upper end 52b Bottom end 53 Press-fit part (lower part) 54 Large diameter section 54a Boundary 55 Main body 55a Second press-fit section 56, 57 beak-shaped part 56a, 57a tip 56b, 57b Upper edge 56c, 57c middle part 56d, 57d Parts other than the middle 58, 59 Plate-shaped part 58a, 59b border 60 Bumper 80 Plug member 82 Plug part 82a Flange 84 Strap part 100 Gastrostomy catheter

Claims

1. A gastrostomy catheter comprising a shaft having a lumen and an anti-reflux valve, The check valve is a plate-shaped base portion disposed to cover the upper end of the shaft; a downward protrusion protruding downward from a central portion of the base; an annular wall portion that rises downward from the peripheral edge of the base portion and surrounds the periphery of the upper end portion of the downward protrusion; and The shaft A body surface contact portion; an annular rib formed along the peripheral edge of the upper end opening of the lumen and standing upward from the body surface abutment portion; and a gap between an inner peripheral surface of the annular wall portion and an outer peripheral surface of an upper end portion of the downward protrusion portion forms an annular groove into which the annular rib is fitted, A slit-shaped valve opening that opens and closes between a closed state and an open state is formed at the lower end of the downward protrusion, A lower portion of the downward protrusion is a press-fit portion that is press-fitted into the upper end portion of the lumen, the press-fit portion has a large-diameter portion whose dimension in a first direction, which is a direction perpendicular to at least both the longitudinal direction of the valve orifice and the axial direction of the shaft, is larger than the inner diameter of the lumen; A gastrostomy catheter in which the dimension of the downward protruding portion in the first direction gradually increases downward at the boundary between the upper portion of the downward protruding portion and the large diameter portion.

2. The gastrostomy catheter according to claim 1, wherein the lower end of the upper part of the downward protrusion is located lower than the lower end of the annular wall portion.

3. The gastrostomy catheter according to claim 1 or 2, wherein the large diameter portion is formed in a cylindrical shape.

4. the downward projection has a body portion including a pair of beak-like portions; The joint between the lower ends of the pair of beak-shaped portions forms the valve opening, The gastrostomy catheter according to claim 1 or 2, wherein the large diameter portion has a pair of plate-like portions that stand upright in both directions in the first direction from the main body portion.

5. 5. The gastrostomy catheter according to claim 1, wherein the annular wall portion has a notch-shaped portion formed therein that connects the annular groove to a space surrounding the annular wall portion.

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