JP2020099380A - Medication catheter - Google Patents

Abstract

To provide a medication catheter capable of delivering a drug to a lesioned site without any leakage and effectively administering the drug while expanding the lesioned site firmly.SOLUTION: A medication catheter 10 includes: an elongated catheter body 20 having an expansion lumen 23 through which a fluid can flow; and a balloon 30 arranged on a distal end side of the catheter body 20. The balloon 30 includes: a first balloon portion 50 capable of forming a first space 56 communicating with the expansion lumen 23 between the balloon and the catheter body 20; and a second balloon portion 60 arranged to cover the first balloon portion 50 and capable of forming a second space 66 between the second balloon portion and the first balloon portion 50. The first balloon portion 50 has an opening portion 59 in which the first space 56 and the second space 66 are opened by an increase of the internal pressure due to the fluid at the time of expansion. The second balloon portion 60 has pores 67 capable of discharging the fluid to the outside of the second balloon portion 60.SELECTED DRAWING: Figure 4

Description

The present invention relates to a drug administration catheter that is inserted into a body lumen such as a blood vessel to administer a drug to a lesion.

In recent years, a balloon catheter which is percutaneously inserted into a body lumen has been used for treating a lesion (stenosis) generated in the body lumen. The procedure using a balloon catheter includes, for example, percutaneous coronary intervention (PCI: Percutaneous Coronary Intervention) and peripheral vascular intervention (EVT: Endovascular Treatment). A balloon catheter usually includes an elongated shaft portion and a balloon provided on the distal side of the shaft portion and expandable in the radial direction. The balloon catheter can push the deflated balloon by expanding the deflated balloon after reaching the lesion in the body through the thin living body lumen.

However, if the lesion area is forcibly expanded, smooth muscle cells may excessively proliferate and new stenosis (restenosis) may develop in the lesion area. For this reason, in recent years, a drug eluting balloon (DEB) or a drug coated balloon (DCB) in which a drug for suppressing stenosis is coated on the outer surface of the balloon is used. When expanded, these balloons come into contact with the lesion and transfer the drug coated on the surface to the lesion.

Since the drug-eluting balloon and the drug-coated balloon have the drug coated on the outer surface of the balloon, the drug may be eluted into the blood before the balloon reaches the lesion. For this reason, for example, Patent Document 1 describes an intravascular drug delivery balloon catheter including a drug carrier on the outer surface of the balloon, which releases a drug when pressure is applied from the outside.

JP, 6-063145, A

The drug carrier of the balloon catheter for intravascular drug administration described in Patent Document 1 may leak the drug when subjected to pressure even at a site other than the lesion site.

The present invention has been made to solve the above-mentioned problems, and a drug administration catheter capable of delivering a drug to a lesion without leaking it and effectively administering the drug while expanding the lesion firmly. The purpose is to provide.

A drug administration catheter that achieves the above object has an elongated catheter body having an expansion lumen through which a fluid can flow, and a balloon that is disposed on the distal end side of the catheter body and that can be expanded by the fluid. The balloon is disposed on the outer periphery of the catheter body on the distal end side, and has a first balloon portion capable of forming a first space communicating with the expansion lumen between the catheter body, and a radially outer side of the first balloon portion. And a second balloon part capable of forming a second space between the first balloon part and the first balloon part, the first balloon part increasing the internal pressure of the fluid when expanded. According to the above, the first space and the second space have an opening portion, and the second balloon portion is formed with pores capable of releasing the fluid to the outside of the second balloon portion. Characterize.

The drug administration catheter configured as described above has a double-structured balloon in which the second balloon part is provided outside the first balloon part, and the first space inside the first balloon part and the first balloon part. And the second space between the second balloon portions communicate with each other by increasing the pressure of the fluid. The fluid that has flowed into the second space from the first space is discharged to the outside through the pores provided in the second balloon portion, and moves to the lesion portion that contacts the outer surface of the second balloon portion. As a result, the drug administration catheter can be delivered without leaking fluid (medicine solution containing a drug) until it reaches the lesion. Further, in the drug administration catheter, the lesion part can be firmly expanded with high pressure by both the first balloon part and the second balloon part until the opening part is opened. Then, the drug administration catheter can effectively administer the drug to the lesioned part after the opening part is opened.

The balloon includes a tubular portion, a distal taper portion that is reduced in diameter toward the distal end on the distal side of the tubular portion, and a proximal taper that is reduced in diameter toward the proximal end on the proximal end side of the tubular portion. And a first balloon portion and a second balloon portion may contact with each other in at least a part of the tubular portion when the balloon is expanded. In the double-structured balloon, the double structure in which the first balloon part and the second balloon part are in contact can apply high pressure with the same outer diameter of the balloon as in the double structure not in contact (Non-Compliant). Or Low-Compliant). Therefore, in the drug administration catheter, when the balloon is expanded, the lesion part can be expanded firmly by the double-structured cylinder part in which the first balloon part and the second balloon part are in contact with each other.

The first balloon part is located on the tip side of the first balloon part and is joined to the catheter body, and the first balloon part is located on the base end side of the first balloon part and is the catheter body. A first proximal end joint part to be joined, wherein the second balloon part is located on the distal end side of the second balloon part and is joined to the catheter body; 2 a second proximal joint portion located on the proximal side of the balloon portion and joined to the catheter body, wherein the first distal joint portion or the first proximal joint portion is the second distal joint portion. At least part of the weak joint portion that is located on the proximal side of the portion and on the distal side of the second proximal joint portion and that has a lower bonding strength than the second distal joint portion and the second proximal joint portion. And the opening may be formed in the weak joint. As a result, the weak joint is separated from the catheter body to form the open part, and the fluid containing the drug can flow from the first space to the second space through the open part. The tubular portion that contacts the lesion does not have an opening, so that the lesion can be expanded firmly. Further, since the weak joint is located on the proximal side of the second distal joint and on the distal side of the second proximal joint, the second balloon portion is not damaged even after the opening portion is opened. The shape can be maintained. Therefore, the drug administration catheter can easily perform the deflation work of the balloon at the time of removal, and the operability and safety are improved.

The first balloon part includes a first tube part, a first tip taper part having a diameter that decreases between the first tube part and the first tip joining part in a tip direction, the first tube part and the first tube part. A first proximal taper portion having a diameter reduced in the proximal direction between the proximal joint portions, and the first distal taper portion or the first proximal taper portion connected to the weak joint portion is Alternatively, they may be separated from each other without contacting the second balloon portion when expanded. This allows the drug administration catheter to form a gap between the first distal taper portion or the first proximal taper portion and the second balloon portion when expanded. As a result, the fluid that has flowed from the first space to the second space through the opening formed in the weakly bonded portion passes through the gap between the first distal taper portion or the first proximal taper portion and the second balloon portion. , It is possible to reach the tubular portion quickly.

The opening portion is formed in a fragile portion of the first balloon portion located in the tubular portion, and the pressure resistance strength of the fragile portion is different from that of the fragile portion of the first balloon portion located in the tubular portion. It may be smaller than the strength. As a result, the opening portion is formed in the tubular portion that contacts the lesion portion, so that the fluid containing the drug that has flowed from the first space to the second space through the opening portion can be quickly and reliably administered to the lesion portion. Further, since the balloon has a double structure formed of the first balloon portion and the second balloon portion, the fragile portion of the first balloon portion has a hard fragile portion before insertion into the lesion portion or before reaching a predetermined pressure. It is possible to prevent accidental damage from being hit.

It is a top view showing the medicine administration catheter concerning a 1st embodiment. It is a figure which shows the front-end|tip part of a chemical|medical agent administration catheter, (A) is a longitudinal cross-sectional view, (B) is a cross-sectional view which follows the AA line of (A). FIG. 6 is a vertical cross-sectional view showing the distal end portion of the drug administration catheter with the balloon expanded. It is a figure which shows the front-end|tip part of the chemical|medical agent administration catheter in the state which opened the opening part, (A) is a longitudinal cross-sectional view, (B) is a cross-sectional view which follows the BB line of (A). It is a longitudinal section showing the 1st modification of a medicine administration catheter. It is a transverse cross section showing a modification of a medicine administration catheter, (A) shows the 2nd modification, (B) shows the 3rd modification, and (C) shows the 4th modification. It is a longitudinal section showing a medicine administration catheter concerning a 2nd embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the dimensions of the drawings may be exaggerated and different from the actual dimensions for convenience of description. In addition, in the present specification and the drawings, components having substantially the same function are designated by the same reference numeral, and a duplicate description will be omitted. In this specification, the side to be inserted into the lumen is referred to as the “tip side”, and the side to be operated is referred to as the “base side”.
<First Embodiment>

As shown in FIGS. 1 and 2, the drug administration catheter 10 according to the first embodiment is a so-called rapid exchange type catheter in which a guide wire lumen 24 for passing a guide wire is provided only in the distal end portion. The drug administration catheter 10 is percutaneously inserted into a blood vessel and is used for delivering a drug to a lesion site of a heart or a blood vessel of a lower leg.

The drug administration catheter 10 includes a long catheter body 20, a balloon 30 arranged at a distal end portion of the catheter body 20, a hub 40 arranged at a proximal end portion of the catheter body 20, and a distal end portion of the catheter body 20. And a marker 70 to be arranged.

The catheter body 20 includes an outer tube 21 which is a tube body having an open distal end and a proximal end, an inner tube 22 which is a tube body disposed inside the outer tube 21, and a tube body which is fixed to the tip of the inner tube 22. And a tip chip 26 which is The outer tube 21 has a proximal end fixed to the hub 40 and a distal end fixed to the balloon 30. An expansion lumen 23, through which a fluid for expanding the balloon 30 flows, is formed inside the hollow of the outer tube 21. The inner pipe 22 is arranged inside the hollow of the tip region of the outer pipe 21. As a result, the distal end of the catheter body 20 has a double pipe structure. A guide wire lumen 24 is formed inside the hollow of the inner tube 22 for passing a guide wire. In the region having the double pipe structure, the aforementioned expansion lumen 23 is located inside the hollow of the outer pipe 21 and outside the inner pipe 22. The base end side opening 25 of the inner pipe 22 penetrates the side wall surface of the outer pipe 21 and opens to the outside. The proximal end opening 25 is an opening on the proximal end side of the guide wire lumen 24. The inner tube 22 projects further to the tip side than the tip of the outer tube 21. The tip tip 26 is a tube body that is more flexible than the inner tube 22, and is fixed to the tip of the inner tube 22. The tip-side opening 27 of the tip tip 26 is a tip-side opening of the guide wire lumen 24. The tip chip 26 may not be provided.

The constituent materials of the outer tube 21, the inner tube 22 and the tip 26 are not particularly limited, and examples thereof include polyolefin (eg, polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or A mixture of two or more of these), a cross-linked polyolefin, a polyvinyl chloride, a polyamide, a polyamide elastomer, a polyester, a polyester elastomer, a polyurethane, a polyurethane elastomer, a fluororesin, a polymer material such as a polyimide, or a mixture thereof is preferably used. Can be used.

The hub 40 is formed with a hub opening 41 that communicates with the expansion lumen 23 of the outer tube 21 and allows an expansion fluid to flow in and out. The hub 40 is fixed to the outer tube 21 while maintaining liquid tightness.

The balloon 30 has a first balloon portion 50 that covers the outer periphery of the catheter body 20 on the distal end side, and a second balloon portion 60 that covers the radially outer side of the first balloon portion 50. The outer peripheral surface of the first balloon portion 50 and the inner peripheral surface of the second balloon portion 60 are in contact with each other at least partially and overlap each other, but can be separated without being joined. The double-structured balloon 30 including the first balloon portion 50 and the second balloon portion 60 includes a tubular portion 31, a distal taper portion 32 located on the distal end side of the tubular portion 31, and a proximal end side of the tubular portion 31. Has a base end taper portion 33 located at. The tubular portion 31 is formed into a cylindrical shape having a substantially constant outer diameter along the axial direction of the balloon 30 when the balloon 30 is expanded. The tip tapered portion 32 is tapered in diameter from the tubular portion 31 toward the tip. The base end taper portion 33 is tapered in diameter toward the base end direction from the tubular portion 31. Since the balloon 30 has a double structure, even if the first balloon portion 50 is damaged, the second balloon portion 60 that covers the first balloon portion 50 leaves fragments or the like of the first balloon portion 50 in the living body. Can be prevented.

The first balloon portion 50 includes a first tubular portion 51, a first distal taper portion 52 located on the distal end side of the first tubular portion 51, and a first base located on the proximal end side of the first tubular portion 51. And an end taper portion 53. The first balloon portion 50 further includes a first distal end joining portion 54 located closer to the distal end side than the first distal end taper portion 52 and a first proximal end joining position located closer to the proximal end side than the first proximal end taper portion 53. And a portion 55.

The first tubular portion 51 is formed to have a cylindrical shape having a substantially constant outer diameter along the axial direction of the first balloon portion 50 when the first balloon portion 50 is expanded. The first tip tapered portion 52 is tapered from the first tubular portion 51 toward the tip. The first tip joining portion 54 is fused to the outer peripheral surface of the tip portion of the inner pipe 22. The first proximal end tapered portion 53 is tapered from the first tubular portion 51 toward the proximal end. The first base end joint portion 55 is fused to the outer peripheral surface of the distal end portion of the outer tube 21. The method of joining the first balloon portion 50 to the catheter main body 20 at the first distal end joint portion 54 and the first proximal end joint portion 55 is not limited to fusion bonding and may be adhered by an adhesive, for example.

A first space 56 is formed inside the hollow of the first balloon unit 50. The first space 56 communicates with the expansion lumen 23. By injecting the expansion fluid into the first space 56 via the expansion lumen 23, the first balloon portion 50 can be expanded. The expansion fluid is a fluid containing a drug (hereinafter referred to as a drug solution). A known drug can be used as the drug. The drug is, for example, paclitaxel, sirolimus, everolimus, zotarolimus, biolimus, or the like.

The first tip joint portion 54 has a weak joint portion 57 having a low joint strength with the inner pipe 22, and a strong joint portion 58 having a higher joint strength than the weak joint portion 57. The bonding strength can be adjusted by the temperature during fusion, the time required for fusion, the pressure applied during fusion, the type of adhesive, and the like. In the present embodiment, the first tip joint portion 54 has two weak joint portions 57 and two strong joint portions 58. The weak joint portions 57 and the strong joint portions 58 are alternately arranged on the outer peripheral surface of the inner pipe 22 at intervals of approximately 90 degrees along the circumferential direction. The first base end joint portion 55 is joined to the outer peripheral surface of the outer tube 21 with a joint strength higher than that of the weak joint portion 57.

The weakly bonded portion 57 can be separated from the inner tube 22 due to an increase in internal pressure caused by the fluid when the first balloon portion 50 is expanded. Therefore, the weak joint portion 57 opens the first space 56 inside the first balloon portion 50 and the second space 66 between the first balloon portion 50 and the second balloon portion 60 from the closed state. An opening portion 59 (see FIG. 4) that can be brought into a state is formed.

The first balloon part 50 has, for example, a single-layer structure formed of one material, but may have a multi-layer structure formed by joining a plurality of materials.

The second balloon portion 60 includes a second tubular portion 61, a second distal taper portion 62 located on the distal end side of the second tubular portion 61, and a second base located on the proximal end side of the second tubular portion 61. And an end taper portion 63. The second balloon portion 60 further includes a second distal end joining portion 64 located on the distal end side with respect to the second distal end taper portion 62 and a second proximal end joining position on the proximal end side with respect to the second proximal end taper portion 63. And a part 65.

The second tubular portion 61 is formed to have a cylindrical shape having a substantially constant outer diameter along the axial direction of the second balloon portion 60 when the second balloon portion 60 is expanded. The second tubular portion 61 forms a double tubular portion 31 together with the first tubular portion 51. The inner diameter of the second tubular portion 61 is substantially equal to the outer diameter of the first tubular portion 51. The second tubular portion 61 is in contact with the outer side of the first tubular portion 51 in the radial direction without being joined to the first tubular portion 51. The second tubular portion 61 may be partially joined to the first tubular portion 51.

The second tip taper portion 62 is tapered from the second tubular portion 61 toward the tip end. The second tip taper portion 62 forms a double tip taper portion 32 together with the first tip taper portion 52. The second tip joining portion 64 is joined to the base end portion of the tip tip 26, that is, the outer peripheral surface of the tip tip 26 near the inner tube 22. The second tip joint portion 64 is located closer to the tip side than the first tip joint portion 54. The second tip taper portion 62 of the tip tip 26 is joined near the base end portion of the tip tip 26, so that the rigidity of the base end portion becomes higher than the rigidity of the tip end portion. Therefore, in the drug administration catheter 10, the change in rigidity (physical properties) at the boundary portion 28 between the distal tip 26 and the inner tube 22 becomes gradual. Therefore, the drug delivery catheter 10 has improved passability when moving in a tortuous body lumen, and kinks and breakage at the boundary portion 28 are suppressed. The second tip joint portion 64 may be joined to the outer peripheral surface of the inner pipe 22 or the boundary portion 28.

The second proximal end taper portion 63 is tapered from the second tubular portion 61 toward the proximal end direction. The second proximal taper portion 63 forms the double proximal taper portion 33 together with the first proximal taper portion 53. The second proximal end joint portion 65 is fused to the outer peripheral surface of the distal end portion of the outer tube 21. The second base end joint portion 65 is located closer to the base end side than the first base end joint portion 55. The method of joining the second balloon portion 60 to the catheter body 20 at the second distal end joint portion 64 and the second proximal end joint portion 65 is not limited to fusion, and may be adhered by, for example, an adhesive.

The second space 66 between the first balloon part 50 and the second balloon part 60 is closed with the first space 56 inside the first balloon part 50. The second balloon portion 60 preferably has a multi-layer structure formed by joining a plurality of materials in order to improve characteristics such as pressure resistance, expansion force, reduction of elongation, and scratch resistance. However, it may have a single layer structure. The number of layers in the multilayer structure is preferably, for example, 2 to 3.

The second tip joining portion 64 is joined to the tip tip 26 with a joining strength higher than that of the weak joining portion 57 of the first tip joining portion 54. The second base end joint portion 65 is joined to the outer pipe 21 with a joint strength higher than that of the weak joint portion 57 of the first tip joint portion 54. Therefore, even if the weak joint portion 57 of the first tip joint portion 54 separates from the inner pipe 22 and the internal pressure of the second space 66 rises, the second tip joint portion 64 and the second base end joint portion 65. Can be suppressed from peeling from the catheter body 20. Further, the second base end joint portion 65 is separated from the first base end joint portion 55 without overlapping the first base end joint portion 55. Therefore, even if the first proximal end joint portion 55 is peeled off from the catheter body 20, the second proximal end joint portion 65 can be maintained in the state of being joined to the catheter body 20.

The outer peripheral surface of the first tip taper portion 52 and the inner peripheral surface of the second tip taper portion 62 are separated without contacting each other in the expanded state of the balloon 30, but may be partially contacted with each other. The first tip taper part 52 and the second tip taper part 62 are catheters at least in a region near the opening part 59, that is, in the radial direction of the drug administration catheter 10, so that the fluid easily flows into the second space 66 from the opening part 59. It is preferable that they are separated in a region close to the main body 20. The outer peripheral surface of the first proximal taper portion 53 and the inner peripheral surface of the second proximal taper portion 63 are partially in contact with each other while the balloon 30 is inflated. Good.

The second balloon portion 60 has a large number of pores 67 penetrating from the inner peripheral surface to the outer peripheral surface. The shape of the pores 67 is not limited as long as the chemical solution can pass therethrough.

The thickness of the first balloon portion 50 is not particularly limited, but is, for example, 10 to 100 μm. The thickness of the second balloon portion 60 is not particularly limited, but is, for example, 10 to 100 μm. The diameter of the pore 67 of the second balloon portion 60 is not particularly limited, but is, for example, 1 to 100 μm.

The joining strength can be defined by the internal pressure when the joining portion is peeled from the joining object when the fluid is injected into the first balloon portion 50 or the second balloon 60 where the joining portion is provided. The bonding strength of the weak bonding portion 57 is not particularly limited, but is, for example, the strength of peeling when the internal pressure of the first balloon portion 50 is 12 atm. The strong joint portion 58 of the first tip joint portion 54 is higher than the joint strength of the weak joint portion 57, for example, has the strength of peeling when the internal pressure of the first balloon portion 50 is 25 atm. The compressive strength of the portions other than the joints of the first balloon portion 50 (the first distal joint portion 54 and the first proximal joint portion 55) is such that the first balloon portion 50 is not damaged before the weak joint portion 57 is peeled off. In addition, it is preferable that it is larger than the joint strength of the weak joint portion 57, for example, larger than 12 atm. The compressive strength of the portion of the first balloon portion 50 other than the joint portion is preferably smaller than the joint strength of the strong joint portion 58 and the first proximal end joint portion 55. The compressive strength can be defined by the internal pressure when a portion other than the joint portion of the first balloon portion 50 or the second balloon 60 is broken when a fluid is injected into the first balloon portion 50 or the second balloon 60. In order to prevent the first balloon portion 50 from falling off the catheter body 20, before the strong joint portion 58 or the first proximal end joint portion 55 of the first distal joint portion 54 is separated from the catheter body 20, This is because it is preferable that the one balloon portion 50 be damaged.

The joint strength of the second distal end joint portion 64 and the second proximal end joint portion 65 is higher than the joint strength of the weak joint portion 57, and is, for example, the strength of peeling when the internal pressure of the second balloon portion 60 is 25 atm. ..

The compressive strength of the portion of the second balloon portion 60 other than the joint portion is preferably smaller than the joint strength of the second distal joint portion 64 and the second proximal joint portion 65. In order to prevent the second balloon portion 60 from falling off, it is preferable that the second balloon portion 60 be damaged before the second distal joint portion 64 or the second proximal joint portion 65 is separated from the catheter body 20. is there. Generally, a high pressure resistant balloon used to surely expand a lesion has a recommended expansion pressure (NP: Nominal Pressure) of 12 atm and a maximum expansion pressure (RBP: Rated Burst Pressure) of 18 atm. Therefore, the compressive strength of the portion of the second balloon portion 60 other than the joint portion (the second distal joint portion 64 and the second proximal joint portion 65) is set to 18 atm, for example.

The outer diameter of the balloon 30 in the expanded state is not particularly limited, but is, for example, 1 to 10 mm. The axial length L1 (see FIG. 2A) of the tubular portion 31 of the balloon 30 is not particularly limited, but is, for example, 5 to 200 mm. The distance L2 (see FIG. 2A) between the base end of the first tip joint portion 54 and the base end of the second tip joint portion 64 is not particularly limited, but is 1 mm, for example.

The constituent material of the balloon 30 is preferably formed of a material having a certain degree of flexibility, such as polyethylene, polypropylene, polybutene, ethylene-propylene copolymer, ethylene-vinyl acetate copolymer, ionomer, or these. Polyolefin such as a mixture of two or more kinds, thermoplastic resin such as soft polyvinyl chloride resin, polyamide, polyamide elastomer, polyester, polyester elastomer, polyurethane and fluororesin, silicone rubber and latex rubber can be used.

The marker 70 is a ring body having an X-ray contrast property (X-ray opacity). Two markers 70 are fixed to the inner tube 22 located inside the balloon 30. The two markers 70 are fixed to the outer peripheral surface of the inner pipe 22 at positions axially separated from each other. The position of the proximal end of the marker 70 on the distal end side coincides with the position of the distal end of the tubular portion 31 of the balloon 30 in the axial direction. The position of the tip end of the marker 70 on the base end side coincides with the position of the base end of the tubular portion 31 of the balloon 30 in the axial direction. That is, the two markers 70 are arranged corresponding to the positions of the distal end and the proximal end of the tubular portion 31 used for expanding the lesion. Thereby, the operator can accurately position the tubular portion 31 with respect to the lesion by confirming the position of the marker 70 under X-ray fluoroscopy.

The inner diameter of the marker 70 is substantially equal to the outer diameter of the inner tube 22. The length of each marker 70 in the axial direction is not particularly limited, but is, for example, about 1 mm. The shape of the marker 70 is not limited to the ring body, and may be a wire wound in a coil shape, for example. The constituent material of the marker 70 is not particularly limited as long as it has an X-ray contrast property (X-ray opacity), but is, for example, platinum, gold, or a material containing these.

Next, a method of using the drug administration catheter 10 according to the first embodiment will be described by taking as an example the case of treating a narrowed portion of a blood vessel.

First, the drug administration catheter 10 is prepared before treating a narrowed portion of a blood vessel. The balloon 30 of the drug administration catheter 10 is deflated. The operator inserts the sheath into the blood vessel of the patient and places the guiding catheter in the blood vessel. Next, a guide wire is inserted into the guiding catheter and passed through the narrowed portion. Subsequently, the guide wire is passed through the guide wire lumen 24 of the drug administration catheter 10, the catheter body 20 is inserted from the sheath into the blood vessel along the guide wire, and the balloon 30 reaches the stenosis. The operator can accurately position the tubular portion 31 of the balloon 30 with respect to the lesion by confirming the position of the marker 70 under fluoroscopy.

With the balloon 30 positioned at the narrowed portion, the medicinal solution is injected through the hub opening 41 by using an indeflator, a syringe, a pump, or the like while grasping the internal pressure of the first space 56. The injected chemical solution flows into the first space 56 inside the first balloon portion 50 through the expansion lumen 23. As a result, the internal pressure of the first space 56 rises, and as shown in FIG. 3, the deflated balloon 30 is expanded and the narrowed portion can be expanded. At this time, the first balloon portion 50 and the second balloon portion 60 are expanded in a state where the first tubular portion 51 and the second tubular portion 61 are in contact with each other. The tubular portion 31 of the double-structured balloon 30 can apply a higher pressure than a single-structured balloon having the same outer diameter. Therefore, the narrowed portion can be expanded firmly with high pressure. The internal pressure of the first space 56 at this time is lower than the joint strength of the weak joint portion 57 of the first balloon portion 50. When the bonding strength of the weak bonding portion 57 is 12 atm, the internal pressure of the first space 56 is less than 12 atm.

Next, the internal pressure of the first space 56 is increased to 12 atm. As a result, the internal pressure of the first space 56 becomes higher than the joint strength of the weak joint portion 57. As a result, as shown in FIG. 4, the weak joint portion 57 separates from the inner pipe 22, and the opening portion 59 between the inner peripheral surface of the weak joint portion 57 and the outer peripheral surface of the inner pipe 22 opens. At this time, since the tip of the first tip joint portion 54 provided with the weak joint portion 57 is separated from the base end of the second tip joint portion 64, the peeling of the weak joint portion 57 from the inner pipe 22 occurs in the second portion. Not blocked by the tip joint portion 64. Therefore, by increasing the internal pressure of the first space 56, the weak joint portion 57 can be effectively separated from the inner pipe 22. It should be noted that when the weak joint portion 57 separates from the inner pipe 22, the strong joint portion 58 located at the first tip joint portion 54 does not separate. The weak joints 57 are provided only at two diagonal positions of the first tip joint 54. Therefore, the distal end portion of the first balloon portion 50 maintains the joint with the inner pipe 22 at least at the strong joint portion 58 and does not fall off the inner pipe 22. Further, by designing the position of the weakly bonded portion 57, the location where the first balloon portion 50 is peeled off can be controlled.

When the opening part 59 is opened, the drug solution flows from the first space 56 inside the first balloon part 50 into the second space 66 between the first balloon part 50 and the second balloon part 60. Since the joint strength of the joint portion (the second distal joint portion 64 and the second proximal joint portion 65) of the second balloon portion 60 and the pressure resistance strength of the second balloon portion 60 other than the joint portion are higher than 12 atm, The 2 balloon part 60 does not peel or burst. Since the first tip taper portion 52 and the second tip taper portion 62 are separated without making contact with each other, the chemical liquid that has passed through the opening portion 59 has a gap between the first tip taper portion 52 and the second tip taper portion 62. It is possible to quickly reach the second space 66 via. Further, since the first tip taper portion 52 does not contact the second tip taper portion 62, when the internal pressure is applied to the first space 56 and a force acts on the first tip taper portion 52, the first tip taper portion is formed. It is possible to prevent 52 from being supported by the second tip taper portion 62 and escaping force to the second tip taper portion 62. Therefore, due to the increase in the internal pressure of the first space 56, a force easily acts on the weak joint portion 57 of the first tip joint portion 54, and the weak joint portion 57 is easily separated from the inner pipe 22.

The chemical liquid flowing into the second space 66 passes through the pores 67 formed in the second balloon portion 60 and is discharged from the outer peripheral surface of the second balloon portion 60. As a result, the drug solution released from the second tubular portion 61 transfers to the blood vessel wall in contact with the outer peripheral surface of the second tubular portion 61. At this time, by adjusting the internal pressure and the release time of the first space 56, the amount of the drug to be transferred to the blood vessel wall can be adjusted to only the required amount.

Next, the drug solution remaining in the balloon 30 is sucked and discharged from the hub opening 41, and the balloon 30 is deflated. As a result, the excess drug solution in the balloon 30 is collected, and thus excessive drug release can be suppressed.

In the first tip joint portion 54, the weak joint portion 57 is separated from the inner pipe 22, but the strong joint portion 58 is not separated. As a result, the distal end portion of the first balloon portion 50 does not fall off the inner tube 22, and the state in which the first balloon portion 50 and the second balloon portion 60 overlap is maintained. Therefore, the balloon 30 can be contracted to a small extent without being bulky in a state where the first balloon portion 50 and the second balloon portion 60 overlap each other. Then, the guide wire and the catheter body 20 are removed from the blood vessel through the sheath. At this time, the catheter body 20 can be easily removed because the balloon 30 is contracted to a small size. Further, since the second balloon portion 60 located outside the first balloon portion 50 is not damaged, even if a fragment or the like is generated from the peeled portion of the first balloon portion 50, it will not be released into the blood vessel. Therefore, the drug administration catheter 10 has high safety.

As described above, the drug administration catheter 10 according to the first embodiment is arranged at the distal end side of the elongated catheter body 20 having the expansion lumen 23 through which the fluid can flow, and is expandable by the fluid. The balloon 30 is provided on the outer periphery of the catheter body 20 on the distal end side, and a first space 56 capable of forming a first space 56 communicating with the expansion lumen 23 between the balloon 30 and the catheter body 20. And a second balloon portion 60 that is arranged so as to cover the outer side in the radial direction of the first balloon portion 50 and that can form a second space 66 between the first balloon portion 50 and the first balloon portion 50. 50 has an opening portion 59 in which the first space 56 and the second space 66 are opened by an increase in internal pressure due to the fluid at the time of expansion, and the second balloon portion 60 transfers the fluid to the outside of the second balloon portion 60. The pores 67 that can be released to

The drug administration catheter 10 configured as described above has the double-structured balloon 30 in which the second balloon portion 60 is provided outside the first balloon portion 50, and the first space 56 inside the first balloon portion 50. And the 2nd space 66 between the 1st balloon part 50 and the 2nd balloon part 60 is open for free passage by fluid pressure rise. The fluid that has flowed into the second space 66 from the first space 56 is discharged to the outside through the pores 67 provided in the second balloon portion 60, and moves to a lesion portion that contacts the outer surface of the second balloon portion 60. .. As a result, the drug administration catheter 10 can be transported without leaking the fluid (medicine solution containing the drug) until it reaches the lesion. For this reason, the drug can be efficiently delivered and the drug can be prevented from acting on the living body at a position other than the intended position. Further, in the drug administration catheter 10, both the first balloon portion 50 and the second balloon portion 60 can firmly expand the lesion portion with high pressure until the opening portion 59 is opened. Then, the drug administration catheter 10 can effectively administer the drug to the lesion site after the opening part 59 is opened.

Further, the balloon 30 includes a tubular portion 31, a distal taper portion 32 that is reduced in diameter toward the distal end on the distal end side of the tubular portion 31, and a diameter on the proximal end side of the tubular portion 31 toward the proximal end direction. When the balloon 30 is expanded, the first balloon portion 50 and the second balloon portion 60 are in contact with each other in at least a part of the tubular portion 31. In the double-structured balloon 30, the double structure in which the first balloon part 50 and the second balloon part 60 are in contact can apply a high pressure with the same outer diameter of the balloon as compared with the double structure in which they are not in contact ( Non-Compliant or Low-Compliant). Therefore, when the balloon 30 is expanded, the drug administration catheter 10 can firmly expand the lesion part by the double-structured cylinder part 31 in contact with the first balloon part 50 and the second balloon part 60.

The first balloon portion 50 is located on the distal end side of the first balloon portion 50 and is joined to the catheter body 20 at the first distal end joining portion 54, and is located on the proximal end side of the first balloon portion 50. A second proximal end portion 55 that is joined to the catheter body 20 with the second balloon portion 60 located on the distal end side of the second balloon portion 60 and joined to the catheter body 20. The distal end joint portion 64 and the second proximal end joint portion 65 located on the proximal end side of the second balloon portion 60 and joined to the catheter body 20 are provided, and the first distal end joint portion 54 or the first base portion. The end joint portion 55 is located closer to the proximal end side than the second distal joint portion 64 and closer to the distal end side than the second proximal joint portion 65, and further than the second distal joint portion 64 and the second proximal joint portion 65. The weak joint portion 57 having a low joint strength is provided at least in part, and the opening portion 59 is formed in the weak joint portion 57. As a result, the weak joint portion 57 is separated from the catheter body 20 to form the opening portion 59, and the fluid containing the drug can flow from the first space 56 into the second space 66 through the opening portion 59. Since the opening portion 59 is not formed in the tubular portion 31 that comes into contact with the lesion portion, the lesion portion can be expanded firmly while maintaining an appropriate strength. Further, since the weak joint portion 57 is located on the proximal side of the second distal joint portion 64 and on the distal side of the second proximal joint portion 65, the second balloon portion 60 is opened even after the opening portion 59 is opened. Can maintain its shape without damage. Therefore, the drug administration catheter 10 can easily perform the deflating operation of the balloon 30 at the time of removal, and the operability and safety are improved.

Further, the first balloon part 50 includes a first tube part 51, a first tip taper part 52 having a diameter reduced in the tip direction between the first tube part 51 and the first tip joining part 54, and a first tube. A first proximal taper portion 53 having a diameter that decreases between the portion 51 and the first proximal joint portion 55 toward the proximal direction, and the first distal taper portion 52 ( Alternatively, the first proximal end taper portion 53) is separated from the second balloon portion 60 without contacting it when expanded. This allows the drug administration catheter 10 to have a gap between the first distal taper portion 52 or the first proximal taper portion 53 and the second balloon portion 60 when expanded. As a result, the fluid (chemical solution) that has flowed into the second space 66 from the first space 56 through the opening 59 formed in the weak joint 57 is transferred to the first tip tapered portion 52 (or the first proximal tapered portion). The tubular portion 31 can be quickly reached through the gap between the two balloon portions 60.

Note that, as in the first modified example shown in FIG. 5, the first base end joint portion 55 and the second base end joint portion 65 may be overlapped and joined to the outer pipe 21. Such a structure can be formed by simultaneously fusing the first balloon portion 50 and the second balloon portion 60 to the outer tube 21. By simultaneously fusing the first balloon portion 50 and the second balloon portion 60 to the outer tube 21, the manufacturing process can be shortened.

Moreover, the structure of the weakly bonded portion 57 is not particularly limited. For example, as in the second modified example shown in FIG. 6A, the first tip joint portion 54 may have four weak joint portions 57 and four strong joint portions 58. The weak joints 57 and the strong joints 58 may be alternately arranged on the outer peripheral surface of the inner pipe 22 at every 45 degrees along the circumferential direction. Further, as in the third modified example shown in FIG. 6B, the first tip joint portion 54 may have one weak joint portion 57 and one strong joint portion 58. Each of the weak joint portion 57 and the strong joint portion 58 may be arranged on the outer peripheral surface of the inner pipe 22 in the range of 180 degrees along the circumferential direction. Further, as in the fourth modified example shown in FIG. 6C, the first tip joint portion 54 may be formed of only one weak joint portion 57 without the strong joint portion 58. As an example of the weakly-bonded portion 57, the present embodiment of FIG. 2B is most preferable, the second modification of FIG. 6A is next preferable, and the third modification of FIG. 6B is next. 6C is preferable, and the fourth modified example of FIG. 6C is next preferable.

Further, the weak joint portion may be provided on the first proximal joint portion 55 instead of the first distal joint portion 54. In this case, it is preferable that the first proximal end taper portion 53 and the second proximal end taper portion 63 are separated from each other without contact during expansion so that the drug solution can easily pass through. Further, the weak joints may be provided on both the first distal joint 54 and the first proximal joint 55.
<Second Embodiment>

In the drug administration catheter 80 according to the second embodiment, as shown in FIG. 7, the opening portion 82 is formed on the first tubular portion 51 instead of the first distal end joint portion 54 or the first proximal end joint portion 55. Thus, it differs from the first embodiment.

The drug administration catheter 80 has a fragile portion 81 in the first tubular portion 51, which is thinner than the other regions of the first balloon portion 50 and has a low pressure resistance. The thickness of the fragile portion 81 is, for example, 5 to 20 μm thinner than the thickness of the other region of the first balloon portion 50, and more preferably 10 to 20 μm. The fragile portion 81 ruptures before the other regions of the first balloon portion 50 due to the increase in the internal pressure of the first space 56. The fragile portion 81 is formed, for example, at substantially the center in the axial direction of the first tubular portion 51 over the entire circumference of the first tubular portion 51. Therefore, when the internal pressure of the first space 56 rises, a part of the fragile portion 81 bursts at a predetermined pressure, and the open portion 82 is formed. As a result, the chemical liquid in the first space 56 can flow into the second space 66 via the opening portion 82. The fragile portion 81 does not have to be thinner than the other region of the first balloon portion 50 as long as it is easier to rupture than the other region of the first balloon portion 50. For example, the weakened portion 81 may be formed of another material that is easier to rupture than other regions of the first balloon portion 50.

As described above, the opening portion 82 is formed in the fragile portion 81 of the first balloon portion 50 located in the tubular portion 31, and the compressive strength of the opening portion 82 is the same as that of the first balloon portion 50 located in the tubular portion 31. It is smaller than the compressive strength of a portion different from the fragile portion 81. As a result, the opening portion 82 is formed in the tubular portion 31 that contacts the lesion portion, so that the fluid containing the drug that has flowed into the second space 66 from the first space 56 through the opening portion 82 is swiftly and reliably delivered to the lesion portion. Can be administered. Further, since the balloon 30 has a double structure formed by the first balloon portion 50 and the second balloon portion 60, the fragile portion 81 of the first balloon portion 50 is inserted at the time of insertion into a lesion or before a predetermined pressure is reached. It is possible to suppress the inadvertent damage caused by hitting a hard lesion or the like.

The position and shape of the fragile portion are not particularly limited. For example, a plurality of fragile portions may be formed in the first tubular portion 51 in the form of a ring around the entire circumference of the first tubular portion 51. Further, the fragile portion may be formed in the first tubular portion 51 in the form of one or more lines extending in the axial direction of the balloon 30. Further, the fragile portion may be formed in a spiral shape on the first tubular portion 51. Further, the fragile portion may be formed on the first distal end tapered portion 52 or the first proximal end tapered portion 53 instead of the first tubular portion 51. In addition, the fragile portion may be formed by combining the above-described plurality of forms. When the balloon 30 is molded, the fragile portion can be formed by making the temperature of the portion to be thinned higher than the temperature of the portion not to be thinned to soften and stretching.

The present invention is not limited to the above-described embodiments, and various modifications can be made by those skilled in the art within the technical idea of the present invention. For example, in the drug administration catheter 10, a stent may be mounted on the balloon 30. The drug administration catheter may be an over-the-wire type in which a guide wire lumen is provided from the distal end to the proximal end of the drug administration catheter. Further, the outer tube and the inner tube forming the catheter body may be integrally formed.

The living body lumen into which the drug administration catheter 10 is inserted is not limited to a blood vessel and may be, for example, a vascular vessel, a ureter, a bile duct, a fallopian tube, a hepatic duct, or the like.

Further, the pores 67 may be partially provided instead of the entire second balloon portion 60. For example, the pores 67 may be provided only in the second tubular portion 61. In this case, the drug solution is discharged only from the second tubular portion 61 that is likely to come into contact with the lesion. Therefore, the drug delivery catheter 10 can efficiently deliver the drug and can suppress the action of the drug on the living tissue other than the target position.

10, 80 Drug administration catheter 20 Catheter body 21 Outer tube 22 Inner tube 23 Expansion lumen 30 Balloon 31 Tube section 32 Tip taper section 33 Base taper section 50 First balloon section 51 First tube section 52 First tip taper section 53 1 base end taper part 54 1st tip joint part 55 1st base end joint part 56 1st space 57 weak joint part 58 strong joint part 59, 82 opening part 60 2nd balloon part 61 2nd cylinder part 62 2nd tip taper Part 63 2nd base end taper part 64 2nd front end joining part 65 2nd base end joining part 66 2nd space 67 Pore 81 Fragile part

Claims (5)

An elongated catheter body having an expanded lumen capable of passing a fluid,
A balloon that is disposed on the distal end side of the catheter body and is expandable by the fluid,
The balloon is disposed on the outer circumference on the distal end side of the catheter body, and a first balloon portion capable of forming a first space communicating with the expansion lumen between the catheter body and a radial direction of the first balloon portion. A second balloon portion arranged to cover the outside and capable of forming a second space between the first balloon portion and the second balloon portion,
The first balloon portion has an opening portion that opens the first space and the second space due to an increase in internal pressure of the fluid when expanded.
The drug delivery catheter, wherein the second balloon portion is formed with pores capable of releasing the fluid to the outside of the second balloon portion. The balloon includes a tubular portion, a distal taper portion that is reduced in diameter toward the distal end on the distal side of the tubular portion, and a proximal taper that is reduced in diameter toward the proximal end on the proximal end side of the tubular portion. 2. The drug administration catheter according to claim 1, wherein the first balloon part and the second balloon part are in contact with each other in at least a part of the tubular part when the balloon is expanded. The first balloon part is located on the tip side of the first balloon part and is joined to the catheter body, and the first balloon part is located on the base end side of the first balloon part and is the catheter body. A first base end joint portion to be joined,
The second balloon portion is located on the distal end side of the second balloon portion and is joined to the catheter body, and the second balloon portion is located on the proximal end side of the second balloon portion and is the catheter body. A second base end joint portion to be joined,
The first distal joint portion or the first proximal joint portion is located on the proximal side of the second distal joint portion and on the distal side of the second proximal joint portion, and the second distal joint portion and At least a portion has a weak joint having a joint strength lower than that of the second base end joint,
The drug delivery catheter according to claim 1, wherein the opening portion is formed in the weakly joined portion. The first balloon part includes a first tube part, a first tip taper part having a diameter that decreases between the first tube part and the first tip joining part in a tip direction, the first tube part and the first tube part. A first proximal taper portion having a diameter reduced toward the proximal direction between the proximal joint portions,
The drug according to claim 3, wherein the first distal taper portion or the first proximal taper portion connected to the weakly joined portion is separated without coming into contact with the second balloon portion during expansion. Administration catheter. The opening portion is formed in a fragile portion of the first balloon portion located in the tubular portion, and the pressure resistance strength of the fragile portion is different from that of the fragile portion of the first balloon portion located in the tubular portion. The drug administration catheter according to claim 1, wherein the drug administration catheter has a strength lower than the strength.

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