catheter

Abstract

The present invention provides a catheter that can improve the efficiency of delivering administered substances to the treatment site via intravascular administration without blocking blood flow. [Solution] The catheter according to the present disclosure comprises a catheter body that partitions an administration lumen, an annular cover portion that covers the radially outer circumference of the catheter body and partitions a blood flow path through which blood can flow, and a connecting portion that connects the catheter body and the annular cover portion, wherein the annular cover portion partitions a side hole, the connecting portion partitions a discharge flow path that communicates with the administration lumen and opens to the outside of the annular cover portion at the position of the side hole, and the annular cover portion comprises an inlet located on the proximal end side in the longitudinal direction of the catheter body from the side hole, an outlet located on the tip side in the longitudinal direction of the side hole, and an expanding portion located on the proximal end side or the tip side in the longitudinal direction of the side hole and capable of expanding radially outward from the side hole.

Description

[Technical Field]

[0001] The present disclosure relates to a catheter. [Background Art]

[0002] Conventionally, there has been known a procedure of administering an administration substance such as a drug or cells to a predetermined region in a blood vessel and retaining the administered substance in this predetermined region. The administered administration substance is supplied, for example, through the surrounding vascular endothelium to a treatment target site such as a diseased tissue. Patent Document 1 describes a balloon catheter used for this type of procedure. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] International Publication No. 2004 / 045702 [Summary of the Invention] [Problem to be Solved by the Invention]

[0004] In the balloon catheter described in Patent Document 1, an administration substance such as a drug or cells is administered to the outside of the catheter body through an injection port of the catheter body. However, in the balloon catheter described in Patent Document 1, blood flow in the blood vessel is temporarily blocked by two balloons arranged side by side in the axial direction. The administration substance is administered into the blood vessel through the injection port of the catheter body located between the two balloons. Since the blood flow is blocked, it is possible to improve the supply efficiency of the administration substance administered into the blood vessel to the treatment target site such as a diseased tissue through the vascular endothelium. On the other hand, in consideration of the physical burden on the patient, it is preferable that blood flow is maintained.

[0005] An object of the present disclosure is to provide a catheter capable of improving the supply efficiency of an administration substance administered into a blood vessel to a treatment target site without blocking blood flow. [Means for Solving the Problem]

[0006] A catheter as a first aspect of this disclosure is (1) A catheter body that has an internally partitioned administration lumen through which the substance to be administered to the living body can flow, The catheter body has an annular cover portion that surrounds the radially outer periphery and demarcates a blood flow path inside through which blood can flow, It comprises a connecting portion that connects the catheter body and the annular cover portion, The aforementioned annular cover portion has side holes partitioned in its side wall. The connecting portion communicates with the administration lumen and internally partitions a discharge channel that opens radially outward at the position of the side hole of the annular cover portion. The aforementioned annular cover portion is Located on the proximal end side in the longitudinal direction of the catheter body from the side hole, there is an inlet through which the blood flows into the blood flow path, Located toward the longitudinal end of the side hole, and having an outlet through which the blood flows out of the blood channel, A catheter comprising: an expanding portion located on the proximal or tip side in the longitudinal direction from the side hole, and capable of expanding radially outward from the side hole.

[0007] A catheter as one embodiment of the present disclosure is (2) The inlet is formed at the base end of the annular cover portion, The enlarged diameter portion is located on the base end side in the longitudinal direction from the side hole, The enlarged portion is a catheter as described in (1) above, which can be enlarged radially outward from the side hole so as to increase the opening area of ​​the inlet.

[0008] A catheter as one embodiment of the present disclosure is (3) The tip surface of the annular cover portion does not have a tip opening that communicates with the blood flow path. The outlet is the catheter described in (1) or (2) above, which is formed on the side wall of the annular cover portion.

[0009] A catheter as one embodiment of the present disclosure is (4) The outer surface of the side wall of the annular cover portion is provided with a tapered outer surface portion that slopes toward the tip in the longitudinal direction from the side hole, such that the outer diameter increases from the base end to the tip in the longitudinal direction. The outlet is the catheter described in (3) above, which opens to the outside at the position of the tapered outer surface.

[0010] A catheter as one embodiment of the present disclosure is (5) The outlet is formed at the tip of the annular cover portion, The enlarged diameter portion is located on the tip side in the longitudinal direction from the side hole, The expanded portion is a catheter as described in (1) above, which can expand radially outward from the side hole so as to increase the opening area of ​​the outlet.

[0011] A catheter as one embodiment of the present disclosure is (6) The inlet is the catheter described in (5) above, which is formed at the base end of the annular cover portion.

[0012] A catheter as one embodiment of the present disclosure is (7) The catheter is one of the above (1) to (6), wherein the tip is connected to the expanding portion and a guide member is provided that can guide the expansion and contraction of the expanding portion by moving along the catheter body. [Effects of the Invention]

[0013] According to this disclosure, it is possible to provide a catheter that can improve the efficiency of supplying administered substances to the treatment site without blocking blood flow. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] [Figure 1] It is a figure showing a catheter as one embodiment of the present disclosure. [Figure 2] It is a perspective view of the distal end portion of the catheter shown in Figure 1. [Figure 3] It is a side view of the distal end portion of the catheter shown in Figure 1. [Figure 4] It is a cross-sectional view taken along line I-I in Figure 3. [Figure 5] It is a cross-sectional view at the same position as Figure 4, showing the diameter-reduced state of the diameter-enlarged portion. [Figure 6] It is a figure showing a state where the catheter shown in Figure 1 is inserted into a blood vessel. [Figure 7] It is a figure showing the state after the diameter-enlarged portion of the annular cover portion is expanded from the state shown in Figure 6. [Figure 8] It is a figure showing a state where an administered substance is discharged from the position of the side hole of the annular cover portion in the state shown in Figure 7. [Figure 9] It is a figure showing the withdrawal operation of the catheter shown in Figure 1, which is performed after the administration of the administered substance is completed in the state shown in Figure 8. [Figure 10] It is a figure showing a catheter as one embodiment of the present disclosure. [Figure 11] It is a cross-sectional view of the distal end portion of the catheter shown in Figure 10. MODE FOR CARRYING OUT THE INVENTION

[0015] Hereinafter, embodiments of the catheter according to the present disclosure will be exemplarily described with reference to the drawings. The same reference numerals are given to the same configurations in each drawing.

[0016] Figure 1 shows a catheter 100 as one embodiment of the catheter according to this disclosure. Figure 2 is a perspective view of the tip of the catheter 100 shown in Figure 1. Figure 3 is a side view of the tip of the catheter 100 shown in Figure 1. Figure 4 is a cross-sectional view of the catheter 100 at the position indicated by line II in Figure 3. The catheter 100 can be inserted percutaneously into the blood vessels of a living body such as a patient. The catheter 100 is inserted into the blood vessel until the annular cover portion 30, which will be described later, reaches a position near the treatment target area such as lesion tissue. Hereinafter, for the sake of convenience of explanation, the position near the treatment target area where the annular cover portion 30 is positioned within the blood vessel will be referred to as the "treatment target area".

[0017] As shown in Figure 4, the catheter 100 comprises a catheter body 10, an annular cover portion 30, and a connecting portion 50.

[0018] As shown in Figures 2 and 4, the catheter body 10 has an internally partitioned administration lumen 10a through which the substance to be administered to the living body can flow. The substance to be administered may be, for example, a drug, cells, extracellular vesicles, etc. The substance to be administered may flow through the administration lumen 10a on its own, or it may flow through the administration lumen 10a in a state where it is mixed with a liquid. As will be described in detail later, the catheter body 10 of this embodiment comprises a tubular portion 11 and a hub portion 12 to which the proximal end of the tubular portion 11 is fixed.

[0019] Hereinafter, in the catheter 100, the longitudinal direction of the catheter body 10 will be described as "longitudinal direction A of the catheter body 10" or simply "longitudinal direction A". Of longitudinal direction A, the direction from the proximal end to the distal end of the catheter body 10 will be simply described as "proximal side A1", and the direction from the distal end to the proximal end of the catheter body 10 will be simply described as "proximal side A2". Furthermore, in the catheter 100, when the catheter body 10 is the central axis, the direction around the central axis will be described as "circumferential direction B of the catheter body 10" or simply "circumferential direction B". In addition, in the catheter 100, when the catheter body 10 is the central axis, the radial direction of a virtual circle centered on the central axis in a cross section perpendicular to this central axis will be described as "radial direction C of the catheter body 10" or simply "radial direction C".

[0020] As shown in Figures 1 to 4, the annular cover portion 30 covers the outer circumference of the catheter body 10 in the radial direction C. Also, as shown in Figures 2 and 4, the annular cover portion 30 internally partitions a blood flow channel 30a through which blood can flow. Furthermore, the annular cover portion 30 partitions side holes 31 in its side walls.

[0021] As shown in Figure 4, the connecting portion 50 connects the catheter body 10 and the annular cover portion 30. In this embodiment, the connecting portion 50 is connected to the tubular portion 11 of the catheter body 10 at its proximal end on the inner side in the radial direction C. Also, in this embodiment, the connecting portion 50 is connected to the annular cover portion 30 at its tip on the outer side in the radial direction C. The catheter 100 in this embodiment has two connecting portions 50. The two connecting portions 50 protrude outward in the radial direction C from the tip of the catheter body 10. The protrusion directions of the two connecting portions 50 from the catheter body 10 are opposite. However, the number and protrusion direction of the connecting portions 50 are not limited to the configuration of this embodiment.

[0022] As shown in Figure 4, the connecting portion 50 communicates with the administration lumen 10a and internally partitions the discharge channel 50a, which opens to the radially C-outward side of the annular cover portion 30 at the position of the side hole 31.

[0023] As shown in Figure 4, the annular cover portion 30 includes an inlet 32 ​​through which blood can flow into the blood flow channel 30a and an outlet 33 through which blood can flow out of the blood flow channel 30a. The inlet 32 ​​is located at the base end A2 in the longitudinal direction A from the side hole 31. The outlet 33 is located at the tip end A1 in the longitudinal direction A from the side hole 31.

[0024] Furthermore, as shown in Figure 4, the annular cover portion 30 is located at the base end A2 in the longitudinal direction A from the side hole 31 and is equipped with an expandable diameter portion 34 that can expand radially outward from the side hole 31 in the radial direction C. In this embodiment, the expandable diameter portion 34 is located at the base end A2 in the longitudinal direction A from the side hole 31, but this configuration is not limited to this. The expandable diameter portion 34 may also be located at the tip end A1 in the longitudinal direction A from the side hole 31. Details of this will be described later (see Figures 10 and 11). However, from the viewpoint of suppressing the effect of blood flow on the administered substance, it is preferable that the expandable diameter portion 34 is located at the base end A2 in the longitudinal direction A from the side hole 31, as in this embodiment. Figures 1 to 4 show the expanded diameter state in which the expandable diameter portion 34 expands radially outward from the side hole 31 in the radial direction C.

[0025] With the catheter 100, the administered substance can be discharged to the outside of the annular cover portion 30 in the radial direction C at the position of the side hole 31 of the annular cover portion 30 through the administration lumen 10a of the catheter body 10 and the discharge channel 50a of the connecting portion 50. Furthermore, with the catheter 100, blood flow can be maintained through the blood channel 30a partitioned inside the annular cover portion 30 while it is inserted into a blood vessel. Blood flows into the blood channel 30a from the inlet 32 ​​located at the proximal end A2 in the longitudinal direction A from the side hole 31. The blood that has flowed into the blood channel 30a then flows out from the blood channel 30a through the outlet 33 located at the tip A1 in the longitudinal direction A from the side hole 31. In this way, with the catheter 100, the administered substance can be administered without interrupting blood flow in a blood vessel.

[0026] Furthermore, the annular cover portion 30 is provided with an enlarged diameter portion 34 located at the proximal end A2 in the longitudinal direction A from the side hole 31. By enlarging the diameter portion 34 radially outward from the side hole 31 in the radial direction C, it is possible to suppress the flow of the administered substance, which is discharged radially outward from the position of the side hole 31, downstream by the blood flow in the blood vessel. As a result, the administered substance administered to the treatment target area in the blood vessel can be efficiently delivered to the treatment target area, such as lesion tissue, through the surrounding vascular endothelium.

[0027] Thus, with the catheter 100, it is possible to improve the efficiency of supplying administered substances to the treatment site via intravascular administration without blocking blood flow.

[0028] Further details of the catheter 100 of this embodiment will be described below.

[0029] As shown in Figures 1 to 4, the catheter 100 of this embodiment includes a guide member 70 in addition to the catheter body 10, annular cover portion 30, and connecting portion 50 described above.

[0030] As shown in Figure 1, the catheter body 10 of this embodiment comprises a tubular portion 11 and a hub portion 12. The administration lumen 10a of this embodiment extends in the longitudinal direction A across the tubular portion 11 and the hub portion 12.

[0031] Furthermore, as shown in Figure 4, the catheter body 10 of this embodiment has an insertion lumen 10b inside through which the guide member 70 is inserted. The insertion lumen 10b of this embodiment is formed in the tubular portion 11 within the wall of the peripheral wall that partitions the administration lumen 10a. In addition, a through hole 10b1 communicating with the insertion lumen 10b is formed in the peripheral wall of the tubular portion 11 of the catheter body 10. The tip of the guide member 70 passes through the insertion lumen 10b and extends to the outside through the through hole 10b1. Furthermore, the catheter body 10 of this embodiment has four insertion lumens 10b partitioned inside. However, the number and position of the insertion lumens 10b are not limited to the configuration of this embodiment and may be set as appropriate according to the number and position of the guide member 70.

[0032] The tubular portion 11 is preferably formed from a flexible material, but the material is not particularly limited. Examples of constituent materials include various thermoplastic elastomers such as styrene-based, polyolefin-based, polyurethane-based, polyester-based, polyamide-based, polyimide-based, polybutadiene-based, trans-polyisoprene-based, fluororubber-based, and chlorinated polyethylene-based materials. One or more of these can be used in combination (polymer alloys, polymer blends, laminates, etc.). Furthermore, a hydrophilic lubricating coating layer that exhibits lubricity when wet may be placed on the outer surface of the tubular portion 11.

[0033] The constituent material of the hub portion 12 is not particularly limited, but examples include polyolefins such as polyethylene, polypropylene, and ethylene-vinyl acetate copolymer, polyurethane, polyamide, polyester, polycarbonate, polybutadiene, polyvinyl chloride, and polyacetal.

[0034] As shown in Figures 1 to 4, the annular cover portion 30 of this embodiment comprises an annular main body portion 35 that partitions the blood flow path 30a internally, and a closing wall 36 that closes the blood flow path 30a at the tip side A1 of the annular main body portion 35. The side wall of the annular cover portion 30 of this embodiment is the annular side wall that forms the annular main body portion 35. Furthermore, the closing wall 36 of this embodiment does not have a tip opening that penetrates in the longitudinal direction A. In other words, the tip surface of the annular cover portion 30 of this embodiment does not have a tip opening that communicates with the blood flow path 30a.

[0035] The inlet 32 ​​in this embodiment is formed at the base end of the annular cover portion 30. As shown in Figures 1 to 4, the enlarged diameter portion 34 in this embodiment is located at the base end A2, as described above.

[0036] Figure 5 is a cross-sectional view at the same position as Figure 4, showing the retracted state of the enlarged diameter portion 34. The enlarged diameter portion 34 in this embodiment can expand and contract between an enlarged state in which it expands radially outward from the side hole 31 (see Figures 1 to 4) and a retracted state in which it contracts radially outward from the side hole 31 (see Figure 5). The expansion and contraction of the enlarged diameter portion 34 in this embodiment can be performed by operating the guide member 70, which will be described later. When inserting the catheter 100 into a blood vessel, the enlarged diameter portion 34 is in the retracted state (see Figure 5). Then, after the annular cover portion 30 reaches the treatment target area in the blood vessel, and before administration of the administered substance begins, the enlarged diameter portion 34 is set to the enlarged state (Figures 1 to 4).

[0037] As shown in Figures 1 to 4, the enlarged diameter portion 34 of this embodiment can be enlarged radially outward from the side hole 31 in the direction C, so as to increase the opening area of ​​the inlet 32. In other words, the enlarged diameter portion 34 of this embodiment is the base end of the annular main body portion 35. By doing so, as described above, it is possible to suppress the administration substance from being carried downstream by the blood flow in the blood vessels, and to increase the opening area of ​​the inlet 32. By increasing the opening area of ​​the inlet 32, blood flows more easily into the blood flow channel 30a. More specifically, the outer and inner diameters of the annular main body portion 35 of the annular cover portion 30 of this embodiment, when the enlarged diameter portion 34 is in its enlarged state (see Figures 1 to 4), gradually increase from the position where the side hole 31 is formed to the base end where the inlet 32 ​​is formed, towards the base end A2.

[0038] Furthermore, as described above, the tip side A1 of the blood flow channel 30a in this embodiment is closed by the closing wall 36. In other words, the tip surface of the annular cover portion 30 in this embodiment does not have a tip opening that communicates with the blood flow channel 30a. Therefore, blood flowing through the blood flow channel 30a does not flow out to the tip side A1. The outlet 33 of the blood flow channel 30a in this embodiment is formed in the side wall of the annular cover portion 30. In other words, the outlet 33 in this embodiment is formed in the annular side wall that constitutes the annular main body portion 35. Therefore, blood flowing through the blood flow channel 30a flows outwards radially C of the annular cover portion 30 through the outlet 33. As described above, the outlet 33 is located on the tip side A1 of the side hole 31. Therefore, the administered substance discharged from the side hole 31 toward the radially outward C direction of the annular cover portion 30 can be prevented from being carried downstream by the blood flow in the blood vessel by the blood flowing out radially outward C from the outlet 33 at the tip side A1, which is downstream of the blood flow (hereinafter referred to as "outflowing blood"). Thus, in this embodiment, the administered substance discharged from the side hole 31 toward the radially outward C direction of the annular cover portion 30 is less affected by the blood flow not only at the proximal end A2, which is upstream of the blood flow, but also at the tip side A1, which is downstream of the blood flow. Specifically, the administered substance discharged at the side hole 31 is protected from the blood flow by the enlarged diameter portion 34 at the proximal end A2, which is upstream of the blood flow. Furthermore, the administered substance discharged at the side hole 31 is less affected by the blood flow in the blood vessel at the tip side A1, which is downstream of the blood flow, due to the outflowing blood from the outlet 33. This makes it possible to further improve the efficiency of supplying the administered substance administered intravascularly to the treatment target.

[0039] Furthermore, as shown in Figures 1 to 3, the outer surface of the side wall of the annular cover portion 30 of this embodiment is provided with a tapered outer surface portion 35a that slopes so that the outer diameter increases from the base end A2 in the longitudinal direction A towards the tip end A1, beyond the side hole 31. More specifically, the outer surface of the annular side wall of the annular main body portion 35 of this embodiment is provided with a tapered outer surface portion 35a beyond the side hole 31 towards the tip end A1. Then, as shown in Figures 1 to 5, the outlet 33 of this embodiment opens to the outside at the position of this tapered outer surface portion 35a. In this way, the blood flowing out from the outlet 33 is more likely to flow outwards in the radial direction C and towards the base end A2 in the longitudinal direction A. In other words, the blood flowing out from the outlet 33 is more likely to flow in a direction that is somewhat contrary to the blood flow in the blood vessel. This further suppresses the downstream flow of the administered substance by the blood flow in the blood vessel.

[0040] Furthermore, the annular body portion 35 of this embodiment includes a first annular portion 37 and a second annular portion 38 made of different constituent materials. The first annular portion 37 is connected to the tip side A1 of the second annular portion 38. In other words, the second annular portion 38 is connected to the base end side A2 of the first annular portion 37. The side hole 31 and outlet 33 of this embodiment are formed in the first annular portion 37. The inlet 32 ​​and enlarged diameter portion 34 of this embodiment are formed in the second annular portion 38. The second annular portion 38 is configured to be more easily deformable in the radial direction C compared to the first annular portion 37. The second annular portion 38 may be made of a material with a smaller Young's modulus compared to the first annular portion 37, for example. In this way, the enlarged diameter portion 34 formed in the second annular portion 38 can be easily expanded and contracted in the radial direction C.

[0041] As shown in Figures 1 to 4, the base end of the second annular portion 38, which serves as the enlarged diameter portion 34 in this embodiment, can be expanded and contracted in the radial direction C by operating the guide member 70, which will be described later.

[0042] The first annular portion 37 of the annular main body portion 35 in this embodiment is preferably formed of a flexible material, but the material is not particularly limited. The constituent material of the first annular portion 37 may be, for example, the same as the constituent material of the tubular portion 11 described above.

[0043] As shown in Figure 4, the second annular portion 38 of the annular main body portion 35 of this embodiment may be composed of a flexible annular film-like member 38a and a frame member 38b that reinforces the film-like member 38a. Examples of materials that make up the film-like member 38a include polyolefins such as polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or mixtures of two or more of these, as well as thermoplastic resins such as soft polyvinyl chloride resin, polyamide, polyamide elastomer, polyester, polyester elastomer, polyurethane, and fluororesin, silicone rubber, and latex rubber. Furthermore, it is preferable that the frame member 38b is made of a material that has sufficient elasticity. Examples of materials that can be used to construct the frame member 38b include various metals such as stainless steel, Ni-Ti alloy, Cu-Zn alloy, Ni-Al alloy, tungsten, tungsten alloy, titanium, titanium alloy, and tantalum, as well as relatively high-rigidity polymer materials such as polyamide, polyimide, ultra-high molecular weight polyethylene, polypropylene, and fluororesins, or combinations thereof as appropriate. Furthermore, the second annular portion 38 of the annular main body portion 35 may be composed solely of the aforementioned film-like member 38a.

[0044] As shown in Figure 4, the connecting portion 50 in this embodiment is a tubular portion that protrudes radially outward C from the tip of the tubular portion 11 of the catheter body 10. The tubular portion serving as the connecting portion 50 in this embodiment is connected to the tubular portion 11 of the catheter body 10. The tubular portion 11 of the catheter body 10 and the connecting portion 50 may be formed integrally, or they may be formed separately and then joined. Furthermore, the tip of the tubular portion serving as the connecting portion 50 in this embodiment is fixed to the annular cover portion 30 while inserted into the side hole 31 of the annular cover portion 30. The method of fixing the annular cover portion 30 and the connecting portion 50 is not particularly limited. The annular cover portion 30 and the connecting portion 50 may be fixed by, for example, adhesive, fusion, etc.

[0045] As shown in Figure 4, the connecting portion 50 in this embodiment extends in a direction perpendicular to the longitudinal direction A, but the configuration is not limited to this. The connecting portion 50 may extend in a direction inclined with respect to the longitudinal direction A, for example.

[0046] The connecting portion 50 in this embodiment is preferably formed of a flexible material, but the material is not particularly limited. The constituent material of the connecting portion 50 may be, for example, the same as the constituent material of the tubular portion 11 described above.

[0047] As shown in Figures 1 to 5, the tip of the guide member 70 is connected to the enlarged diameter portion 34. Specifically, the tip of the guide member 70 in this embodiment is connected to the base end of the second annular portion 38 of the annular main body portion 35 of the annular cover portion 30. The tip of the guide member 70 in this embodiment is curved so that it faces outward in the radial direction C as it approaches the tip side A1 in the longitudinal direction A.

[0048] The guide member 70 is movable along the catheter body 10. Specifically, as described above, the guide member 70 is inserted into the insertion lumen 10b of the catheter body 10, thereby moving along the longitudinal direction A of the catheter body 10. The tip of the guide member 70 extends to the outside of the catheter body 10 through the through hole 10b1.

[0049] Furthermore, the catheter 100 of this embodiment is equipped with four guide members 70. The four guide members 70 are spaced apart in the circumferential direction B. The tips of the four guide members 70 are connected to the base end of the second annular portion 38 at different positions in the circumferential direction B.

[0050] Therefore, by moving the guide member 70 along the catheter body 10 to the tip side A1 in the longitudinal direction A, the proximal end of the second annular portion 38 can be expanded outward in the radial direction C. In other words, by moving the guide member 70 along the catheter body 10 to the tip side A1 in the longitudinal direction A, the expansion movement of the expansion portion 34 can be guided. Conversely, by moving the guide member 70 along the catheter body 10 to the proximal end side A2 in the longitudinal direction A, the proximal end of the second annular portion 38 can be reduced inward in the radial direction C. In other words, by moving the guide member 70 along the catheter body 10 to the proximal end side A2 in the longitudinal direction A, the reduction movement of the expansion portion 34 can be guided. In this way, the provision of the guide member 70 allows the expansion and contraction movement of the expansion portion 34 of the annular cover portion 30 to be guided.

[0051] As shown in Figure 1, the guide member 70 may be inserted into the insertion lumen 10b such that its proximal end protrudes from the proximal end of the catheter body 10. In this way, the guide member 70 can be moved in the longitudinal direction A by manipulating the proximal end of the guide member 70. In Figure 1, an operating section 70a is shown where the proximal ends of four guide members 70 are combined into one, but each of the four proximal ends of the guide members 70 may protrude separately from the proximal end of the catheter body 10.

[0052] The guide member 70 is preferably made of a flexible and elastic material. Examples of materials for the guide member 70 include various metals such as stainless steel, Ni-Ti alloy, Cu-Zn alloy, Ni-Al alloy, tungsten, tungsten alloy, titanium, titanium alloy, and tantalum, as well as relatively rigid polymer materials such as polyamide, polyimide, ultra-high molecular weight polyethylene, polypropylene, and fluororesin, or combinations thereof as appropriate.

[0053] Next, with reference to Figures 6 to 9, an example of a treatment method for the target area Y using the catheter 100 of this embodiment will be described.

[0054] Figure 6 shows the catheter 100 inserted into the blood vessel BV. As shown in Figure 6, when inserting the catheter 100 into the blood vessel BV, the enlarged diameter portion 34 of the annular cover portion 30 is in a reduced diameter state. As shown in Figure 6, the catheter 100 is inserted into the blood vessel BV until the annular cover portion 30 located at its tip reaches the vicinity of the treatment target Y.

[0055] Figure 7 shows the state in which the enlarged diameter portion 34 of the annular cover portion 30 is enlarged by operating the guide member 70 from the state shown in Figure 6. From the state shown in Figure 6, by moving the guide member 70 to the tip side A1 in the longitudinal direction A, the base end of the second annular portion 38 is pressed outward in the radial direction C by the tip of the guide member 70. This makes it possible to change the base end of the second annular portion 38, which is the enlarged diameter portion 34, from a reduced diameter state (see Figure 6) to an enlarged diameter state (see Figure 7).

[0056] Figure 8 shows the state in which the administered substance X is discharged radially outward C from the position of the side hole 31 of the annular cover portion 30, as shown in Figure 7. As described above, the administered substance X administered into the blood vessel BV is protected from blood flow by the enlarged diameter portion 34 of the annular cover portion 30. Therefore, the administered substance X is more likely to remain near the treatment target area Y within the blood vessel BV, and the efficiency of supplying the administered substance X administered into the blood vessel BV to the treatment target area Y can be improved.

[0057] Furthermore, as shown in Figure 8, while administering substance X into the blood vessel BV, blood flow within the blood vessel BV can be maintained through the blood flow channel 30a (see Figure 4) inside the annular cover portion 30.

[0058] Furthermore, as described above, the outlet 33 of the annular cover portion 30 is formed on the tapered outer surface portion 35a. Therefore, the blood flowing out from the outlet 33 (see the white arrow in Figure 8) makes it easier for the administered substance X to remain near the treatment target area Y within the blood vessel BV. This improves the efficiency of supplying the administered substance X administered into the blood vessel BV to the treatment target area Y.

[0059] Figure 9 shows the catheter 100 removal operation performed after the administration of substance X in the state shown in Figure 8 is complete. As shown in Figure 9, after the administration of substance X is complete, the guide member 70 is operated to change the diameter expansion section 34 from the expanded state to the contracted state. By contracting the diameter expansion section 34, the catheter 100 can be removed from the body.

[0060] Next, a catheter 200, which is another embodiment of the catheter according to the present disclosure, will be described. Figure 10 is a diagram showing the catheter 200. Figure 11 is a cross-sectional view of the tip of the catheter 200. Compared with the catheter 100 described above, the catheter 200 of this embodiment differs in the configuration of the annular cover portion 230 and the arrangement of the guide member 70, but the other configurations are the same. Therefore, here we will mainly describe the differences of the catheter 200 as described above, and omit the description of the configurations that are common with the catheter 100 described above.

[0061] As shown in Figure 11, the catheter 200 comprises a catheter body 10, an annular cover portion 230, a connecting portion 50, and a guide member 70. The catheter body 10 and the connecting portion 50 are the same as those of the catheter 100 described above, so their explanation is omitted here.

[0062] In this embodiment, the annular cover portion 230 covers the outer circumference of the catheter body 10 in the radial direction C, and internally partitions a blood flow path 230a through which blood can flow. The annular cover portion 230 also partitions side holes 231 in its side walls.

[0063] The annular cover portion 230 includes an inlet 232, an outlet 233, and an enlarged diameter portion 234. The inlet 232 is located at the proximal end A2 in the longitudinal direction A of the catheter body 10, relative to the side hole 231. Blood flows from the inlet 232 into the blood flow path 230a. The outlet 233 is located at the tip A1 in the longitudinal direction A of the side hole 231. The blood that flows from the inlet 232 into the blood flow path 230a flows out from the outlet 233.

[0064] The enlarged diameter portion 234 is located at the tip side A1 in the longitudinal direction A from the side hole 231. The enlarged diameter portion 234 can be enlarged radially outward C from the side hole 231.

[0065] As described above, in the annular cover portion 230 of this embodiment, the enlarged diameter portion 234 is located at the tip side A1 in the longitudinal direction A from the side hole 231. In this way, the enlarged diameter portion 234 is positioned at the tip side A1, which is downstream of the blood flow to the administered substance administered into the blood vessel. This suppresses the administered substance from being carried downstream by the blood flow. As a result, the administered substance administered into the blood vessel is more likely to remain near the treatment site, and the efficiency of supplying the administered substance to the treatment site through the vascular endothelium can be improved. In addition, blood flow can be maintained by the blood flow channel 230a inside the annular cover portion 230. Therefore, the catheter 200 can improve the efficiency of supplying the administered substance administered into the blood vessel to the treatment site without blocking the blood flow.

[0066] Furthermore, the annular cover portion 230 of this embodiment does not have an expandable portion that can expand radially outward from the side hole 231 in the proximal A2 direction. Therefore, the administered substance administered into the blood vessel from the position of the side hole 231 is easily affected by the blood flow from the proximal A2 side, which is the upstream side of the blood flow. As a result, with the catheter 200 of this embodiment, the administered substance is less likely to flow downstream with the blood flow, and the administered substance can be agitated by the influence of the blood flow from the proximal A2 side. This makes it possible to suppress the retention of the administered substance administered into the blood vessel without approaching the vascular endothelium, and improve the efficiency of supplying the administered substance to the treatment target.

[0067] As shown in Figure 11, the annular cover portion 230 of this embodiment consists of an annular side wall that partitions the blood flow path 230a inside. In other words, the tip side A1 and the proximal end side A2 of the blood flow path 230a of this embodiment are open to the outside.

[0068] In this embodiment, the outlet 233 is formed at the tip of the annular cover portion 230. As shown in Figure 11, the enlarged diameter portion 234 in this embodiment is located at the tip A1, as described above, from the side hole 231. Figures 10 and 11 show the enlarged state of the enlarged diameter portion 234.

[0069] The expanding portion 234 of this embodiment can expand and contract between an expanded state in which it expands radially outward from the side hole 231 (see Figure 11) and a contracted state in which it contracts radially inward from the side hole 31. The expansion and contraction of the expanding portion 234 of this embodiment can be performed by operating the guide member 70. When inserting the catheter 200 into a blood vessel, the expanding portion 234 is in the contracted state. Then, after the annular cover portion 230 reaches the treatment target area in the blood vessel, and before administration of the administered substance is started, the expanding portion 234 is expanded (see Figure 11).

[0070] As shown in Figure 11, the enlarged diameter portion 234 of this embodiment can be enlarged radially outward C from the side hole 231 so as to increase the opening area of ​​the outlet 233. In other words, the enlarged diameter portion 234 of this embodiment is the tip of the side wall of the annular cover portion 230. In this way, as described above, it is possible to suppress the downstream flow of the administered substance administered into the blood vessel by the blood flow in the blood vessel, and to increase the opening area of ​​the outlet 233. As the opening area of ​​the outlet 233 increases, blood flows out of the outlet 233 more easily, and as a result, blood flows more easily through the blood flow path 230a. More specifically, the outer diameter and inner diameter of the annular cover portion 230 of this embodiment gradually increase from the position where the side hole 231 is formed to the tip where the outlet 233 is formed, towards the tip side A1.

[0071] Furthermore, the inlet 232 in this embodiment is formed at the base end of the annular cover portion 230. In other words, blood flows into the blood flow path 230a from the inlet 232 formed at the base end of the annular cover portion 230 and flows out from the outlet 233 formed at the tip of the annular cover portion 230.

[0072] Furthermore, the annular cover portion 230 of this embodiment includes a first annular portion 237 and a second annular portion 238 made of different constituent materials. The first annular portion 237 is connected to the base end side A2 of the second annular portion 238. In other words, the second annular portion 238 is connected to the tip side A1 of the first annular portion 237. The side holes 231 and inlet 232 of this embodiment are formed in the first annular portion 237. The outlet 233 and enlarged diameter portion 234 of this embodiment are formed in the second annular portion 238. The second annular portion 238 is configured to be more easily deformable in the radial direction C compared to the first annular portion 237. The second annular portion 238 may be made of a material with a smaller Young's modulus compared to the first annular portion 237, for example. In this way, the enlarged diameter portion 234 formed in the second annular portion 238 can be easily expanded and contracted in the radial direction C.

[0073] As shown in Figure 11, the tip of the second annular portion 238, which serves as the enlarged diameter portion 234 in this embodiment, can be expanded and contracted in the radial direction C by operating the guide member 70.

[0074] The first annular portion 237 of this embodiment may be made of the same constituent material as the first annular portion 37 described above. Similarly, the second annular portion 238 of this embodiment may also comprise a membrane member 238a and a bone member 238b, and may be made of the same constituent material as the second annular portion 38 described above.

[0075] Next, the arrangement of the guide member 70 in the catheter 200 of this embodiment will be described. As shown in Figure 11, the guide member 70 of this embodiment is inserted into the insertion lumen 10b of the catheter body 10. The tip of the guide member 70 of this embodiment extends to the outside of the catheter body 10 through a through hole 10b1 that communicates with the insertion lumen 10b. The tip of the guide member 70 is connected to the tip of the second annular portion 238, which serves as an enlarged diameter portion 234.

[0076] As shown in Figure 11, the catheter 200 of this embodiment is provided with a winding portion 280 around the tip of the guide member 70 so that the expanded diameter portion 234 can expand and contract radially in the C direction when the guide member 70 moves in the longitudinal direction A. The winding portion 280 may be attached, for example, to the tubular portion 11 or the connecting portion 50 of the catheter body 10. Alternatively, the winding portion 280 may be formed integrally with the tubular portion 11 or the connecting portion 50 of the catheter body 10. The guide member 70 may be shape-memorized in a position where the expanded diameter portion 234 is in an expanded state (see Figure 11). In other words, the guide member 70 may be configured to be shape-memorized in the position shown in Figure 11. In this way, by moving the guide member 70 to the proximal end A2 in the longitudinal direction A from the state shown in Figure 11, the expanded diameter portion 234 can be reduced inward in the radial direction C. Furthermore, by moving the guide member 70 to the tip side A1 in the longitudinal direction A, the enlarged diameter portion 234 can be brought to the enlarged diameter state shown in Figure 11, starting from the state in which the enlarged diameter portion 234 is reduced in diameter.

[0077] Although the catheter 200 of this embodiment is equipped with a winding portion 280, it is sufficient that the expansion and contraction of the diameter-expanding portion 234 can be performed by moving the guide member 70 along the catheter body 10, and the configuration is not limited to one equipped with a winding portion 280.

[0078] The catheter relating to this disclosure is not limited to the specific configuration shown in the embodiments described above, and various modifications, changes, and combinations are possible as long as they do not deviate from the scope of the claims. [Industrial applicability]

[0079] This disclosure relates to catheters. [Explanation of Symbols]

[0080] 10: Catheter body 10a: Administration lumen 10b: Insertion lumens 10b1: Passing hole 11:Tubular part 12: Hub section 30, 230: Annular cover section 30a, 230a: Blood flow channels 31, 231: Side hole 32, 232: Inlet 33, 233: Outlet 34, 234: Expanded diameter part 35: Ring-shaped main body 36: Closed wall 37, 237: First Ring Section 38, 238: Second Ring Section 38a, 238a: Membrane member 38b, 238b: Structural members 50:Connection part 50a: Discharge channel 70: Guide member 70a: Operation unit 100, 200: Catheter 280: Winding section A: Long direction A1: Tip A2: Proximal side B: Circumferential direction C: Radial direction BV: Blood vessel X: administered substance Y: Treatment area

Claims

1. A catheter body that has an internally partitioned administration lumen through which the substance to be administered to the living body can flow, The catheter body has an annular cover portion that surrounds the radially outer periphery and demarcates a blood flow path inside through which blood can flow, It comprises a connecting portion that connects the catheter body and the annular cover portion, The aforementioned annular cover portion has side holes partitioned in its side wall. The connecting portion communicates with the administration lumen and internally partitions a discharge channel that opens radially outward at the position of the side hole of the annular cover portion. The aforementioned annular cover portion is Located on the proximal end side in the longitudinal direction of the catheter body from the side hole, there is an inlet through which the blood flows into the blood flow path, Located toward the longitudinal end of the side hole, and having an outlet through which the blood flows out of the blood channel, A catheter comprising a diameter-expanding portion located on the proximal or tip side in the longitudinal direction from the side hole, and capable of expanding in diameter outward in the radial direction from the side hole.

2. The inlet is formed at the base end of the annular cover portion, The enlarged diameter portion is located on the base end side in the longitudinal direction from the side hole, The catheter according to claim 1, wherein the enlarged diameter portion is expandable radially outward from the side hole so as to increase the opening area of ​​the inlet.

3. The tip surface of the annular cover portion does not have a tip opening that communicates with the blood flow path. The catheter according to claim 1 or 2, wherein the outlet is formed in the side wall of the annular cover portion.

4. The outer surface of the side wall of the annular cover portion is provided with a tapered outer surface portion that slopes toward the tip in the longitudinal direction from the side hole, such that the outer diameter increases from the base end to the tip in the longitudinal direction. The catheter according to claim 3, wherein the outlet opens to the outside at the position of the tapered outer surface.

5. The outlet is formed at the tip of the annular cover portion, The enlarged diameter portion is located on the tip side in the longitudinal direction from the side hole, The catheter according to claim 1, wherein the enlarged diameter portion is expandable radially outward from the side hole so as to increase the opening area of ​​the outlet.

6. The catheter according to claim 5, wherein the inlet is formed at the base end of the annular cover portion.

7. The catheter according to claim 1 or 2, comprising a guide member whose tip is connected to the expanded diameter portion and which moves along the catheter body to guide the expansion and contraction of the expanded diameter portion.

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