Balloon catheter

Abstract

The utility model relates to a balloon catheter, which comprises a far outer tube, a far inner tube and a far outer tube, a proximal outer tube having a proximal outer tube lumen and disposed on the proximal side of the distal outer tube; an inner tube having a guidewire lumen through which a guidewire can be inserted, the inner tube being disposed within the distal outer tube lumen, the distal end of the inner tube protruding from the distal end of the distal outer tube; a hand tube having a hand tube lumen and disposed on the proximal side of the proximal outer tube; a pressurizer connection part that is joined to the proximal side of the hand tube; and a balloon, the distal end of which is joined to the vicinity of the distal end of the inner tube, the proximal end of which is joined to the distal end of the distal outer tube, and the outer surface of which has one or more protrusions formed integrally with the balloon. The ratio of the length from the distal end of the inner tube to the distal end of the hand tube to the length from the distal end of the inner tube to the proximal end of the exposed portion of the hand tube is greater than 0.23 and less than 0.29.

Description

Technical Field

[0001] The utility model relates to a balloon catheter. Background Art

[0002] Diseases such as angina pectoris and myocardial infarction are caused by the formation of a stenosis in the inner wall of a blood vessel that has hardened due to calcification. As one of the treatments for these diseases, there is angioplasty, which uses a balloon catheter to dilate the stenosis. Angioplasty is a low-invasive treatment that does not require open-chest surgery such as bypass surgery and is widely performed.

[0003] In angioplasty surgery, a balloon catheter is generally used. However, if a highly rigid proximal tube (proximal tube) made of stainless steel (SUS) of a balloon catheter is placed at the curved portion of the aortic arch, the efficiency of transmitting the force from the proximal portion to the front end when the catheter is pushed is reduced (kickback phenomenon), for example, see Patent Documents 1 to 3.

[0004] In addition, the cutting balloon catheter has multiple elements (protrusions) configured on the balloon surface, which can introduce cracks into the lesion and expand it through the elements. Therefore, it is used in calcified lesions that are difficult to expand with a balloon catheter without elements, and ISR (In-Stent-Restenosis) lesions where the neointimum is soft and easy to slide.

[0005] Although the cutting balloon catheter with metal elements fixed on the outer surface of the balloon has excellent ability to introduce cracks into lesions, the balloon has high rigidity and there are problems with the penetration of lesions. Moreover, compared with balloon catheters without elements, not only is the rigidity of the balloon part high, but the outer diameter is also large. Therefore, the efficiency of transmitting the force from the hand portion to the front end when operating the balloon catheter is further sought.

[0006] Therefore, it is expected that a cutting balloon catheter having a resin element and a balloon formed integrally therewith has lower rigidity and better lesion penetration than a cutting balloon catheter having a metal element, and since the element and the balloon are integrated, the risk of the element falling off in the blood vessel is reduced.

[0007] Patent document 1: CN102652852A

[0008] Patent Document 2: WO2018 / 008515

[0009] Patent document 3: US5425711A Utility Model Content

[0010] The utility model provides a balloon catheter, which is formed by lengthening the length of the guide wire port (the length from the front end of the balloon catheter to the guide wire port) and the length of the proximal outer tube (the length from the front end of the balloon catheter to the distal end of the hand tube), so that when the balloon is inserted into the peripheral blood vessels of the coronary artery, the hard hand tube will not affect the structure of the aortic arch, and the reduction in the transmission efficiency of the force when pushing and cutting the balloon catheter from the hand part to the front end part (recoil phenomenon) is suppressed.

[0011] In addition, by setting the guidewire port length longer, the coaxiality between the guidewire and the cutting balloon catheter is improved, and the efficiency of force transmission to the front end is improved.

[0012] In addition, by shortening the length of the proximal outer tube, the distance that the proximal outer tube bends when the catheter is pushed in is shortened, and the efficiency of transmitting force to the distal end is further improved.

[0013] In addition, by lengthening the protruding length of the reinforcement body, the efficiency of transmitting force to the front end is further improved.

[0014] In addition, by lengthening the distal portion (the distal end portion) of the distal sleeve of the balloon, the insertability of the distal end is improved, and the efficiency of force transmission to the distal end portion is further improved.

[0015] The balloon catheter of the present invention is described as follows.

[0016] [1] A balloon catheter comprising: a distal outer tube having a distal outer tube lumen; a proximal outer tube having a proximal outer tube lumen and arranged on the proximal side of the distal outer tube; an inner tube having a guidewire lumen through which a guidewire can be inserted, the inner tube being arranged in the distal outer tube lumen, the distal end of the inner tube protruding from the distal end of the distal outer tube; a hand tube having a hand tube lumen and arranged on the proximal side of the proximal outer tube; and a pressurizer connecting portion connected to the proximal side of the hand tube. combination; and a balloon, wherein the distal end of the balloon is joined to the vicinity of the distal end of the inner tube, the proximal end of the balloon is joined to the distal end of the distal outer tube, the outer surface of the balloon has one or more protrusions formed integrally with the balloon, and the ratio of the length from the distal end of the inner tube to the distal end of the hand tube to the length from the distal end of the inner tube to the proximal end of the exposed portion of the hand tube is greater than 0.23 and less than 0.29.

[0017] In the balloon catheter formed as in [1], the rigid side tube made of SUS is not inserted into the aortic arch, so that recoil does not occur (the front end of the catheter returns to the proximal side of the blood vessel due to the shape recovery of the side tube). In addition, the balloon catheter is inserted from the femoral artery of the thigh, and the side tube is inserted until it passes through the aorta and is about to reach the aortic arch, thereby improving the pushability and the transmission efficiency of the operating load to the front end of the balloon catheter. In addition, the protrusion of the balloon is formed by a resin integrally molded with the balloon, so that the blood vessel penetration is improved compared with the protrusion formed of metal, and the risk of the protrusion falling off in the blood vessel is reduced.

[0018] Preferably, the balloon catheter of the present invention is the following [2] to

[15]

[0019] [2] The balloon catheter according to [1], wherein:

[0020] The proximal end of the inner tube forms a guide wire opening between the proximal end of the distal outer tube and the distal end of the proximal outer tube.

[0021] The ratio of the length from the distal end of the inner tube to the guide wire port to the length from the distal end of the inner tube to the distal end of the hand tube is 0.70 or more and 0.85 or less.

[0022] [3] The balloon catheter according to [2], wherein:

[0023] The ratio of the length from the distal end of the inner tube to the guide wire port to the length from the distal end of the inner tube to the distal end of the hand tube is 0.75 or more and 0.80 or less.

[0024] In a balloon catheter formed as described in [2] and [3], by making the ratio of the length from the distal end of the inner tube to the guidewire port to the length from the distal end of the inner tube to the distal end of the hand tube to be 0.70 or more or 0.75 or more, the length of the guidewire inserted through the inner tube becomes longer, and the coaxiality of the guidewire and the balloon catheter is improved. In addition, by making the length of the proximal outer tube shorter, the length of the proximal outer tube bending when the balloon catheter is pushed into the blood vessel can be shortened, and the efficiency of force transmission from the hand side to the front end of the balloon catheter can be improved during operation. In addition, by making the ratio of the length from the distal end of the inner tube to the guidewire port to the length from the distal end of the inner tube to the distal end of the hand tube to be 0.85 or less or 0.80 or less, the excellent operability and rapid exchangeability of the RX (Rapid Exchange) type balloon catheter can be maintained.

[0025] [4] The balloon catheter according to [1], further comprising:

[0026] The reinforcing body protrudes from the inner lumen of the hand tube and is arranged in at least a portion of the inner lumen of the distal outer tube and the inner lumen of the proximal outer tube.

[0027] In the balloon catheter formed as in [4], the rigidity balance between the SUS proximal tube and the resin proximal outer tube is improved by making the reinforcing body protrude further from the proximal tube.

[0028] [5] The balloon catheter according to [4], wherein:

[0029] The protruding length of the reinforcement body from the distal end of the hand pipe to the distal end of the reinforcement body is greater than 200 mm.

[0030] In a balloon catheter formed as described in [5], by making the protruding length of the reinforcement body from the distal end of the hand tube to the distal end of the reinforcement body greater than 200 mm, the reinforcement body is arranged near the front end of the balloon catheter, thereby making it easier to transmit the force from the hand to the front end during operation.

[0031] [6] The balloon catheter according to [4], wherein:

[0032] A ratio of a protruding length of the reinforcement body from a distal end of the hand tube to a distal end of the reinforcement body to a length from a distal end of the inner tube to a distal end of the hand tube is 0.5 or more and 1 or less.

[0033] In a balloon catheter formed as in [6], by making the ratio of the protruding length of the above-mentioned reinforcement body from the distal end of the above-mentioned hand tube to the distal end of the above-mentioned reinforcement body to the length from the distal end of the above-mentioned inner tube to the distal end of the above-mentioned hand tube be greater than 0.5, it is easier to transmit the force from the hand to the front end during operation.

[0034] [7] The balloon catheter according to [6], wherein:

[0035] A ratio of a protruding length of the reinforcement body from a distal end of the hand tube to a distal end of the reinforcement body to a length from a distal end of the inner tube to a distal end of the hand tube is 0.65 or less.

[0036] In a balloon catheter formed as described in [7], the flexibility near the front end of the balloon catheter can be ensured by making the ratio of the protruding length of the reinforcement body from the distal end of the hand tube to the distal end of the reinforcement body to the length from the distal end of the inner tube to the distal end of the hand tube be less than 0.65.

[0037] [8] The balloon catheter according to any one of [1] to [7], wherein

[0038] The balloon comprises: a straight tube portion; a distal cone portion located at the distal side of the straight tube portion; a proximal cone portion located at the proximal side of the straight tube portion; a distal sleeve portion located at the distal side of the distal cone portion; and a proximal sleeve portion located at the proximal side of the proximal cone portion.

[0039] At least a portion between the distal end of the inner tube and the distal end of the distal sleeve portion is provided with a tip portion.

[0040] The axial length from the distal end of the inner tube to the distal end of the distal tapered portion is 5 mm or more.

[0041] [9] The balloon catheter according to any one of [1] to [7], wherein

[0042] The balloon comprises: a straight tube portion; a distal cone portion located at the distal side of the straight tube portion; a proximal cone portion located at the proximal side of the straight tube portion; a distal sleeve portion located at the distal side of the distal cone portion; and a proximal sleeve portion located at the proximal side of the proximal cone portion.

[0043] At least a portion between the distal end of the inner tube and the distal end of the distal sleeve portion is provided with a tip portion.

[0044] A ratio of an axial length from a distal end of the inner tube to a distal end of the distal tapered portion to an axial length of the straight tube portion of the balloon is 0.4 or more.

[0045] In a balloon catheter formed as described in [8] and [9], by configuring a front end tip and lengthening the axial length from the distal end of the inner tube to the distal end of the distal cone, the outer diameter from the distal end of the balloon to the front end of the balloon catheter (the distal end of the inner tube) changes slowly, making it easier to insert into a narrow blood vessel and to transmit force from the hand to the front end during operation.

[0046]

[10] The balloon catheter according to any one of [1] to [7], wherein

[0047] At least a portion of the surface of the balloon and at least a portion of the surface of the distal outer tube are coated with a hydrophilic coating.

[0048] In a balloon catheter formed as in

[10] , a hydrophilic coating is applied to the surface of the balloon and the surface of the distal outer tube, thereby making it easier to insert the catheter into the blood vessel, thereby making it easier to transmit the force from the hand side to the front end during operation.

[0049]

[11] The balloon catheter according to

[10] , wherein:

[0050] A lubricating coating is applied to at least a portion of the surface of the above-mentioned pipe at hand.

[0051] In a balloon catheter formed as in

[11] , a lubricating coating is applied to the proximal tube, thereby facilitating insertion into a blood vessel, thereby making it easier to transmit the force from the proximal to the distal end during operation.

[0052]

[12] The balloon catheter according to

[10] , wherein:

[0053] At least a portion of the surface of the balloon or at least a portion of the surface of the tube at hand is coated with a hydrophobic coating.

[0054] In a balloon catheter formed as in

[12] , by coating at least a portion of the surface of the balloon with a hydrophobic coating, the balloon is less likely to slip when expanding a narrowed portion of a blood vessel. By coating at least a portion of the surface of the hand tube with a hydrophobic coating, the hand tube is less likely to slip when touched by an operator, thereby improving operability.

[0055]

[13] The balloon catheter according to any one of [1] to [7], wherein:

[0056] At least a portion of the surface of the balloon includes a drug coating.

[0057] In a balloon catheter as described in

[13] , the surface of the balloon includes a drug that inhibits re-stenosis, so that when the balloon is expanded, the drug is transferred to the inner wall of the blood vessel, thereby inhibiting re-stenosis of the blood vessel.

[0058]

[14] A balloon catheter according to any one of [1] to [7], wherein the balloon has a balloon outer layer located radially outward and a balloon inner layer located radially inward, and the material of the balloon outer layer is different from the material of the balloon inner layer.

[0059] In a balloon catheter formed as described in

[14] , by making the balloon a double-layer balloon having an outer layer and an inner layer made of different materials, the balloon can be provided with well-balanced properties of pressure resistance and elasticity. BRIEF DESCRIPTION OF THE DRAWINGS

[0060] Figure 1 A side view showing a balloon catheter according to an embodiment of the present invention.

[0061] Figure 2 Indicates along Figure 1 Cross-sectional view along line AA.

[0062] Figure 3 A partial cross-sectional view showing the balloon and its surroundings cut along the axial direction of the balloon catheter.

[0063] Figure 4 is with Figure 2 A corresponding cross-sectional view of another embodiment. DETAILED DESCRIPTION

[0064] The present invention is specifically described below based on the implementation modes, but the present invention is certainly not limited by the following implementation modes. It is undoubtedly possible to implement the present invention with appropriate changes within the scope of the above / below-mentioned subject matter, and they are all included in the technical scope of the present invention. In addition, in each of the drawings, for convenience, there are cases where hatching, component figure marks, etc. are omitted. In this case, please refer to the specification and other drawings. In addition, the sizes of various components in the drawings are preferentially conducive to understanding the features of the present invention, and therefore there are cases where the sizes are different from the actual sizes.

[0065] Reference Figure 1 to Figure 4 A balloon catheter according to an embodiment of the present invention will be described. Figure 1 A side view showing a balloon catheter according to an embodiment of the present invention is shown. Figure 2 Indicates along Figure 1 The cross-sectional view of line AA, Figure 3 A partial cross-sectional view of the balloon and its surroundings cut along the axial direction of the balloon catheter is shown. Figure 4 is with Figure 2 A corresponding cross-sectional view of another embodiment.

[0066] In the present invention, the proximal side refers to the direction of the user's hand side relative to the extension direction or axial direction of the balloon catheter, and the distal side refers to the opposite direction of the proximal side, that is, the direction of the treatment subject side.

[0067] As an example of the balloon catheter involved in the utility model, Figure 1As shown, it can include: a distal outer tube 30, which is made of PEBAX7233 with an outer diameter / inner diameter of 0.92 / 0.76 mm and has a distal outer tube lumen; a proximal outer tube 40, which is made of Rilsamid with an outer diameter / inner diameter of 0.93 / 0.73 mm and has a proximal outer tube lumen, and is arranged on the proximal side of the above-mentioned distal outer tube 30; an inner tube 20, which is made of a single structure of a three-layer tube of Rilsamid / MODIC / HB530 or a structure formed by connecting three-layer tubes with an outer diameter / inner diameter of 0.61 / 0.43 mm and has a guide wire lumen that can be inserted with a guide wire, and the above-mentioned inner tube 20 is arranged on the above-mentioned distal outer tube 30. The inner tube 20 is located in the inner cavity of the distal outer tube, and the distal end of the inner tube 20 protrudes from the distal end of the distal outer tube 30; the hand tube 50 is composed of SUS according to 0.70 / 0.54mm (which can be provided with PTFE coating), has a hand tube inner cavity, and is arranged on the proximal side of the proximal outer tube 40, and 2 indicator marks are arranged on the proximal side of the hand tube 50; and the balloon 10 is composed of PEBAX7233, the distal end of the balloon 10 is connected to the vicinity of the distal end of the inner tube 20, the proximal end of the balloon 10 is connected to the distal end of the distal outer tube 30, and the outer surface of the balloon 10 has more than one protrusion 18.

[0068] The diameter of the balloon 10 can be 1.5-4.5 mm, in which case the balloon membrane thickness is about 15-40 μm, and the height of the protrusion is 0.15-0.40 mm (including the membrane thickness). The material of the balloon 10 includes one or more of thermoplastics, elastomers, or elastomer-thermoplastics. In some examples, one or more of acrylonitrile butadiene styrene (ABS), polyamide (e.g., nylon), polyamide 6 (PA 6) or polyamide 66 (PA 66), polyamide 12 (PA 12), polycarbonate (PC), polyethylene (e.g., high-density polyethylene (HDPE) or low-density polyethylene (LDPE)), polymethyl methacrylate (PMMA), polyoxymethylene (POM), polypropylene (PP), polystyrene (PS), polybutylene terephthalate (PBT), styrene acrylonitrile resin (SAN), thermoplastic elastomer (TPE) (e.g., polyether block amide (PEBA)), polyphenylene sulfide (PPS), polyether ether ketone (PEEK), polyurethane, polyester, or blends, copolymers, or co-extrudates thereof are included. In some examples, TPE (or PEBA) may include materials sold under the brand names Arkema of Paris, France or Evonik Industries of Essen, Germany. In some examples, thermoplastics may include materials sold under the brand name (EMS-Grivory of Domat / Ems, Switzerland), including amide thermoplastics. Polyamide elastomers such as Pebax7233 or Pebax5533 or polyamide 12 such as Rilsamid are particularly preferred. The average breaking pressure of the balloon can have a range of 3.0 to 4.0 MPa. In the balloon catheter, the guide wire port (GWP) length (axial length from the front end of the balloon catheter 1 to the guide wire port) is 240 to 310 mm, the axial length of the proximal outer tube 40 is 80 to 125 mm, and the effective length of the balloon catheter is 1440 to 1480 mm. Among them, the effective length refers to the length from the distal end of the inner tube 20 to the proximal end of the exposed part of the hand tube 50, specifically, it refers to the length from the distal end of the balloon catheter 1 to the distal end of the pressurizer connecting part 80. If a strain relief part 90 is embedded in the distal end of the pressurizer connecting part 80, it refers to the length from the distal end of the balloon catheter 1 to the distal end of the strain relief part 90.

[0069] It is preferable that the ratio of the length from the distal end of the inner tube 20 to the distal end of the hand tube 50 to the effective length is greater than 0.23 and less than 0.29.

[0070] According to the balloon catheter 10 of the utility model, the rigid hand tube 50 made of SUS is not inserted into the aortic arch, so that recoil (the front end of the catheter returns to the proximal side of the blood vessel due to the shape recovery of the hand tube 50) does not occur. In addition, the balloon catheter 10 is inserted from the femoral artery of the thigh, and the hand tube 50 is inserted until it passes through the aorta and is about to reach the aortic arch, thereby improving the pushability and the transmission efficiency of the operating load to the front end of the balloon catheter 10.

[0071] It is preferred that the proximal end of the inner tube 20 forms a guide wire port 70 between the proximal end of the distal outer tube 30 and the distal end of the proximal outer tube 40, and the ratio of the length from the distal end of the inner tube 20 to the guide wire port 70 to the length from the distal end of the inner tube 20 to the distal end of the hand tube 50 is 0.70 or more and 0.85 or less. In addition, it is further preferred that the ratio of the length from the distal end of the inner tube 20 to the guide wire port 70 to the length from the distal end of the inner tube 20 to the distal end of the hand tube 50 is 0.75 or more and 0.80 or less.

[0072] Thus, by making the ratio of the length from the distal end of the inner tube 20 to the guidewire port 70 to the length from the distal end of the inner tube 20 to the distal end of the hand tube 50 to be 0.70 or more or 0.75 or more, the length of the guidewire inserted through the inner tube 20 becomes longer, and the coaxiality of the guidewire and the balloon 10 catheter is improved. In addition, by making the length of the proximal outer tube 40 shorter, the length of the proximal outer tube 40 bending when the balloon catheter 1 is pushed into the blood vessel can be shortened, and the efficiency of force transmission from the hand side to the front end of the balloon catheter 1 can be improved during operation. In addition, by making the ratio of the length from the distal end of the inner tube 20 to the guidewire port 70 to the length from the distal end of the inner tube 20 to the distal end of the hand tube 50 to be 0.85 or less or 0.80 or less, the excellent operability and rapid exchangeability of the balloon catheter, which are unique to the RX (Rapid Exchange) type balloon catheter, can be maintained.

[0073] Preferably, the balloon catheter 1 further includes a reinforcing body 60 protruding from the hand tube lumen and disposed in at least a portion of the distal outer tube lumen and the proximal outer tube lumen.

[0074] In this way, by making the reinforcing body 60 further protrude from the proximal tube 50 , the rigidity balance between the proximal tube 50 made of SUS and the proximal outer tube 40 made of resin is improved.

[0075] It is preferable that the protruding length of the reinforcement body 60 from the distal end of the hand pipe 50 to the distal end of the reinforcement body 60 is greater than 200 mm.

[0076] In this way, by making the protruding length of the above-mentioned reinforcement body 60 from the distal end of the above-mentioned hand tube 50 to the distal end of the above-mentioned reinforcement body 60 greater than 200 mm, the reinforcement body 60 is configured near the front end of the balloon catheter 1, thereby making it easier to transmit the force from the hand to the front end during operation.

[0077] It is preferred that a ratio of a protruding length of the reinforcement body 60 from the distal end of the hand tube 50 to the distal end of the reinforcement body 60 to a length from the distal end of the inner tube 20 to the distal end of the hand tube 50 is 0.5 or more and 1 or less.

[0078] In this way, by making the ratio of the protruding length of the above-mentioned reinforcement body 60 from the distal end of the above-mentioned hand tube 50 to the distal end of the above-mentioned reinforcement body 60 relative to the length from the distal end of the above-mentioned inner tube 20 to the distal end of the above-mentioned hand tube 50 be greater than 0.5, it is easier to transmit the force from the hand to the front end during operation.

[0079] It is preferable that the ratio of the protruding length of the reinforcement body 60 from the distal end of the hand tube 50 to the distal end of the reinforcement body 60 to the length from the distal end of the inner tube 20 to the distal end of the hand tube 50 is 0.65 or less.

[0080] In this way, by making the ratio of the protruding length of the above-mentioned reinforcement body 60 from the distal end of the above-mentioned hand tube 50 to the distal end of the above-mentioned reinforcement body 60 relative to the length from the distal end of the above-mentioned inner tube 20 to the distal end of the above-mentioned hand tube 50 be less than 0.65, the flexibility near the front end of the balloon catheter 1 can be ensured.

[0081] like Figure 2 As mentioned above, it is preferred that the protrusion 18 and the balloon 10 are formed integrally.

[0082] In this way, by forming the protrusion 18 of the balloon 10 using the resin integrally molded with the balloon 10 , the insertability into the blood vessel is improved compared to the protrusion 18 formed of metal, and the risk of the protrusion 18 falling off in the blood vessel is reduced.

[0083] like Figure 3As shown, the balloon 10 preferably comprises: a straight tube portion 14; a distal cone portion 13 located on the distal side of the straight tube portion 14; a proximal cone portion 15 located on the proximal side of the straight tube portion 14; a distal sleeve portion 12 located on the distal side of the distal cone portion 13; and a proximal sleeve portion 16 located on the proximal side of the proximal cone portion 15, and at least a portion between the distal end of the inner tube 20 and the distal end of the distal sleeve portion 12 comprises a front end tip 11, which is made of PEBAX5533. The axial length from the distal end of the inner tube 20 to the distal end of the distal cone portion 13 is preferably 5 mm or more, and may be 6.5 mm; or preferably, the ratio of the axial length from the distal end of the inner tube 20 to the distal end of the distal cone portion 13 to the axial length of the straight tube portion 14 of the balloon 10 is 0.4 or more.

[0084] In this way, by configuring the front end tip 11 and lengthening the axial length from the distal end of the inner tube 20 to the distal end of the distal cone 13, the outer diameter from the distal end of the balloon 10 to the front end of the balloon catheter 1 (the distal end of the inner tube 20) changes slowly, making it easier to insert into narrow blood vessels and easier to transmit force from the hand to the front end during operation.

[0085] In addition, the inner tube 20 inside the balloon 10 may also be provided with an X-ray opaque marker in the axial direction at the portion where the balloon 10 is located, so that the position of the balloon 10 can be confirmed under X-ray fluoroscopy. The X-ray opaque marker is preferably arranged at positions corresponding to both ends of the straight tube portion 14 of the balloon 10, or may be arranged at a position corresponding to the axial center of the straight tube portion 14.

[0086] Preferably, at least a portion of the surface of the balloon 10 and at least a portion of the surface of the distal outer tube 30 are coated with a hydrophilic coating. The material constituting the hydrophilic coating can be any material as long as it can absorb water and show swelling. For example, a hydrophilic material can be cited. As for the hydrophilic material, cellulose-based polymers (such as hydroxypropyl cellulose), maleic anhydride-based polymers (such as maleic anhydride copolymers such as methyl vinyl ether-maleic anhydride copolymers), polyethylene oxide-based polymers (such as polyethylene glycol), acrylamide-based polymers (such as polyacrylamide, block copolymers of polymethacrylate-dimethylacrylamide (PGMA-DMAA)), water-soluble nylon (registered trademark), polyvinyl alcohol, polyvinyl pyrrolidone and other well-known hydrophilic substances can be cited.

[0087] In this way, by coating the surface of the balloon 10 and the surface of the distal outer tube 30 with a hydrophilic coating, the balloon 10 and the distal outer tube 30 can be easily inserted into the blood vessel, thereby making it easier to transmit the force from the hand side to the front end during operation.

[0088] It is preferable that at least a portion of the surface of the hand pipe 50 is coated with a lubricating coating.

[0089] In this way, by applying a lubricating coating to the hand side tube 50, it is easy to insert it into the blood vessel, so that the force from the hand side to the front end during operation is more easily transmitted.

[0090] Preferably, at least a portion of the surface of the balloon 10 or at least a portion of the surface of the hand tube 50 is coated with a hydrophobic coating. The material constituting the hydrophobic coating 42 can be any material as long as it shows hydrophobicity. For example, hydrophobic materials can be cited. For hydrophobic materials, reaction-curable silicone, fluoroethylene propylene (FEP), polytetrafluoroethylene (PTFE), substances with low surface free energy that are end-capped with alkyl or perfluoroalkyl groups, etc. can be cited. In addition, a hydrophobic coating that exhibits hydrophobicity can also be formed by plasma irradiation using fluorine-based gases or laser micromachining.

[0091] In this way, by coating at least a portion of the surface of the balloon 10 with a hydrophobic coating, it is not easy to slip when expanding the narrow part of the blood vessel. By coating at least a portion of the surface of the hand tube 50 with a hydrophobic coating, it is not easy to slip when the operator touches it with his hands during operation, and the operability is improved.

[0092] Preferably, at least a portion of the surface of the balloon 10 includes a drug coating.

[0093] The drug constituting the drug coating is not particularly limited as long as it is a pharmacologically active substance, and for example, non-gene therapy drugs, gene therapy drugs, small molecules, cells and other pharmaceutically permitted drugs can be listed. In particular, when the balloon catheter 1 is used for the purpose of inhibiting the re-stenosis of blood vessels after treatment during angioplasty, anti-re-stenosis agents such as antiproliferative agents and immunosuppressants can be preferably used as drugs, and specifically, drugs such as paclitaxel, zotaxel, elotaxel, and sirolimus (rapamycin) can be used. Only one of these drugs can be used, or two or more can be used.

[0094] In addition, the medicament can not only be attached to the outer side of the balloon 10, but also be impregnated in the balloon 10, and can also be maintained in the balloon 10 in the form of microcapsules. In addition, in addition to containing pharmacologically active substances, the medicament can also contain an auxiliary agent for improving the dispersibility, transferability to the vascular wall, solubility, and storage stability of the medicament. As auxiliary agents, stabilizers, adhesives, bases, excipients, disintegrants, preservatives, moisture-proof agents, solvents, dissolution aids, etc. are used. Specifically, lactose, dextrin, white sugar, xylitol, mannitol, erythritol, carboxymethyl cellulose, hydroxycellulose, oxidized cellulose, hydroxymethyl cellulose and other sugars, benzoates, ethylenediamine, potassium iodide, polysorbate, urea, butylated hydroxytoluene, ascorbic acid, sodium pyrosulfite, tocopherol, parabens, benzoic acid, benzalkonium chloride, alginate, gum arabic, glycerol, etc. can be cited.

[0095] In order to suppress the drug from dissolving or falling into the blood during delivery, the drug may be protected by the coating layer and held in the balloon 10. The coating layer may be formed of a water-soluble polymer or a hydrophobic polymer, a lipid, a sugar, a surfactant, or the like.

[0096] In addition, the auxiliary agent or coating layer has the advantages of being able to arrange a larger amount of drugs with a higher density on the balloon 10, and being able to improve the transferability of the arranged drugs to the blood vessel wall. By providing the auxiliary agent or coating layer on the desired part of the balloon 10, the dissolution or shedding of the arranged drugs during delivery to the lesion can be suppressed, and more drugs can be delivered to the target lesion. Since there are drugs whose therapeutic effects depend on the dosage, by arranging more drugs on the balloon 10, it can help improve the therapeutic effect.

[0097] In this way, by including a drug that inhibits re-stenosis on the surface of the balloon 10 , the drug is transferred to the inner wall of the blood vessel when the balloon 10 is expanded, thereby inhibiting the blood vessel from re-stenosis.

[0098] like Figure 4 As shown, the balloon 10 preferably comprises a balloon outer layer 10b located radially outward and a balloon inner layer 10a located radially inward, and the material of the balloon outer layer 10b is different from the material of the balloon inner layer 10a.

[0099] The inner layer 10a and the outer layer 10b of the balloon 10 can be formed of any suitable material that provides the properties described herein. In some examples, the inner layer 10a and the outer layer 10b each include one or more of a thermoplastic, an elastomer, or an elastomeric thermoplastic. The inner layer 10a and the outer layer 10b can use the materials of the balloon 10 described above.

[0100] In this way, by making the balloon 10 a double-layer balloon 10 including an outer layer and an inner layer made of different materials, it is possible to provide the balloon 10 with well-balanced properties of pressure resistance and elasticity.

[0101] Next, a method for manufacturing the above-mentioned balloon 10 will be described.

[0102] First, a tubular parison is produced by extrusion molding to be the source of the balloon 10. The tubular parison is formed into a circular tube shape, and a ridge extending in the axial direction is formed on its outer peripheral surface. The ridge has a triangular cross-section, and a plurality of (specifically, three) ridges are formed at equal intervals along the circumference of the tubular parison.

[0103] Next, after the tubular parison is stretched in the longitudinal direction, blow molding is performed under predetermined conditions using a mold having a housing space corresponding to the shape of the balloon 10. During the blow molding, the tubular parison is heated and expanded in the mold (housing space). Through the blow molding, the tubular parison is in a biaxially stretched state, and then the balloon 10 is manufactured by cutting both ends of the stretched tubular parison.

[0104] Here, in the mold used for blow molding, a groove for accommodating each protrusion is formed in the portion corresponding to the straight tube portion 14 of the balloon 10. Thus, each protrusion is formed in the portion of the tubular blank where the straight tube portion 14 is formed by blow molding. In the mold, a groove for accommodating the protrusion may also be formed in the portion corresponding to the distal cone portion 13 and the proximal cone portion 15 of the balloon 10. Thus, each protrusion is formed in the portion of the tubular blank where the distal cone portion 13 and the proximal cone portion 15 are formed by blow molding. On the other hand, in the mold, a groove for accommodating the protrusion may not be formed in the portion corresponding to the distal cone portion 13 and the proximal cone portion 15 of the balloon 10. Therefore, during blow molding, each protrusion is pushed by the mold in the portion of the tubular blank where the distal cone portion 13 and the proximal cone portion 15 are formed and becomes compressed (crushed). Thus, the protrusions (outer protrusions) that protrude toward the outer circumference are not formed in the portions of the tubular parison that form the distal taper 13 and the proximal taper 15. In this case, the crushed ridges protrude toward the inner circumference of the tubular parison, and the protrusions (inner protrusions) are formed in the portions of the tubular parison that form the distal taper 13 and the proximal taper 15.

[0105] It should be noted that in the mold, grooves for accommodating the protrusions are also formed in the portions corresponding to the distal sleeve portion 12 and the proximal sleeve portion 16 of the balloon 10. Therefore, by blow molding, the portions of the tubular parison where the distal sleeve portion 12 and the proximal sleeve portion 16 are formed also form protrusions protruding toward the outer circumference. After blow molding, these protrusions are cut off.

[0106] The above is a description of the method for manufacturing the balloon 10. It should be noted that the method for manufacturing the balloon 10 is not necessarily limited to the method described above, and other manufacturing methods may also be used.

[0107] In addition, in order to confirm the effect of the present invention, balloon catheters of Examples 1 and 2 and Comparative Examples 1 and 2 were prepared and their performance was evaluated. The specifications and performance evaluation results of the balloon catheters of Examples 1 and 2 and Comparative Examples 1 and 2 are shown in Table 1.

[0108] Table 1

[0109]

[0110] Example 1

[0111] Preparation of test samples

[0112] A schematic diagram of the test specimen used in this experiment is shown in Figure 1As shown. In the cutting balloon, the expansion diameter is 2.5 mm, the axial length of the straight tube portion 14 of the balloon is 15 mm, and the height of the protrusion 18 is 0.3 mm. The base end of the proximal sleeve portion 16 of the balloon 10 is fused to the front end of the distal outer tube 30, and the inner tube 20 is arranged in the inner cavity of the balloon 10 and the inner cavity of the distal outer tube, so that the inner tube 20 protrudes from the front end of the distal sleeve portion 12 of the balloon 10. The front end tip 11 is arranged in the area of ​​the inner tube 20 protruding from the front end of the distal sleeve portion 12 of the balloon 10 and in contact with the front end of the distal sleeve portion 12 of the balloon 10, and then the inner tube 20, the front end of the distal sleeve portion 12 of the balloon 10, and the front end tip 11 are fused, and the inner tube 20 is cut in a manner that the axial length from the front end of the distal cone portion 13 of the balloon 10 to the front end of the inner tube 20 is 4.5 mm. Then, the base end of the distal outer tube 30, the front end of the proximal outer tube 40, and the base end of the inner tube 20 are welded to form a guide wire port 70 (GWP). Here, it is made in a manner that the length from the front end of the inner tube 20 to the front end of the proximal outer tube 40 is 320 mm. The hand tube 50 is coated with polytetrafluoroethylene resin on SUS316L, and a reinforcement body 60 made of SUS304 is arranged at the distal position of the hand tube lumen. The reinforcement body 60 is welded to the hand tube lumen in a manner that protrudes 205 mm from the distal end of the hand tube 50. The reinforcement body 60 is arranged in the distal outer tube lumen and the proximal outer tube lumen, and the base end of the proximal outer tube 40 is joined to the front end of the hand tube 50. Here, it is made in a manner that the length from the front end of the inner tube 20 to the front end of the hand tube 50 is 385 mm. After a strain relief 90 is arranged around the base end of the hand tube 50, the pressurizer connection part 80 is joined to the base end of the hand tube 50, and the strain relief 90 is fitted with the pressurizer connection part 80. Here, the effective length of the balloon catheter 1 (in the case of this sample, the length from the front end of the inner tube 20 to the distal end of the strain relief 90 (the proximal end of the hand tube 50)) is 1460 mm. Two test samples were produced.

[0113] Example 2

[0114] Preparation of test samples

[0115] The same method as in Example 1 was used except that the length from the front end of the inner tube 20 to the front end of the proximal outer tube 40 was 300 mm and the length from the front end of the inner tube 20 to the front end of the hand tube 50 was 365 mm.

[0116] Comparative Example 1

[0117] Preparation of test samples

[0118] The same method as in Example 1 was used except that the length from the front end of the inner tube 20 to the front end of the proximal outer tube 40 was 370 mm and the length from the front end of the inner tube 20 to the front end of the hand tube 50 was 435 mm.

[0119] Comparative Example 2

[0120] Preparation of test samples

[0121] The same method as in Example 1 was used except that the length from the front end of the inner tube 20 to the front end of the proximal outer tube 40 was 270 mm and the length from the front end of the inner tube 20 to the front end of the hand tube 50 was 335 mm.

[0122] Terminal arrival performance evaluation

[0123] Use of test equipment

[0124] ·sink

[0125] Simulated aortic arch

[0126] Simulated coronary artery

[0127] Digital force gauge

[0128] Actuator

[0129] Medical equipment

[0130] ·Guiding catheter: 6Fr JL 3.5 (BRITE Sheath Introducer)

[0131] Guide wire: 0.014 inch (ASAHI SION blue)

[0132] Pressurizing device (Demax pressurizer)

[0133] Syringe: 50ml (lockable Terumo syringe)

[0134] Three-way stopcock valve (Marquis Stopcock valve kit)

[0135] Y-connector (Goodtec Y-connector kit)

[0136] Test methods

[0137] Evaluation loop preparation

[0138] The simulated aortic arch, simulated coronary artery, guide catheter (hereinafter referred to as GC) and Y-type connector are installed in the water tank. The tip of the guide wire (hereinafter referred to as GW) is configured to extend from the distal outlet of the simulated coronary artery. The digital force gauge is installed on the actuator and the power is turned on.

[0139] Determination method

[0140] Flush the inner lumen of the inner tube 20 of the balloon catheter 1, and pass the balloon catheter 1 from the GW base end. Connect the pressurizer to apply negative pressure. Place the front end of the balloon catheter 1 at the proximal entrance of the simulated coronary artery, and fix the pressurizer connection part 80 of the balloon catheter 1 using a clamp installed on the load change evaluation device. Using an actuator, insert the balloon catheter 1 200mm into the simulated coronary artery loop at a certain speed. Use 2 test samples prepared to perform one evaluation each (a total of 2 evaluations), and record the maximum value of the digital force gauge as the maximum load. In addition, the data displayed by the digital force gauge is rounded off to the second decimal place as the obtained data.

[0141] Test results

[0142] The results of Examples 1 and 2 and Comparative Examples 1 and 2 are shown in Table 1. The states of the test samples of Examples 1 and 2 and Comparative Example 1 after the test were confirmed. In Examples 1 and 2, the hand tube 50 is configured in a straight line along the aortic part simulating the aortic arch, and the front end of the hand tube 50 is configured to be about to reach the arched part of the simulated aortic arch. The hand tube 50 will not be bent by the arched part of the simulated aortic arch, and the balloon 10 with the protrusion can be delivered to the distal end of the simulated coronary artery. On the other hand, in Comparative Example 1, the hand tube 50 is configured in a straight line along the aortic part simulating the aortic arch, but the front end of the hand tube 50 is configured on the insertion port side farther from the arched part of the simulated aortic arch than in Examples 1 and 2. Comparative Example 1 is presumed to be that since the front end of the hand tube 50 is far away from the arched part of the simulated aortic arch, the hand operating force cannot be fully transmitted to the balloon 10 at the front end, and the balloon 10 needs a load to reach the distal end of the simulated coronary artery compared to Examples 1 and 2. In addition, in the test of Comparative Example 2, it was confirmed that when the front end of the hand tube 50 reached the arch-shaped portion simulating the aortic arch, the rigid hand tube 50 made of SUS could not deform along the arch-shaped portion and wanted to return to the original straight shape, causing recoil (the phenomenon that the front end of the balloon catheter 1 retreats backward). Based on the above, Examples 1 and 2 do not cause recoil caused by passing through the arch-shaped portion of the aortic arch, and by inserting the hand tube 50 until it is about to reach the arch-shaped portion of the aortic arch, the pushing performance (pushing performance) of the hand tube 50 can be maximized, and even a balloon 10 that is difficult to insert into a blood vessel such as a cutting balloon 10 can improve the reachability of the distal end of the coronary artery.

Claims

1. A balloon catheter, characterized in that: have: a distal outer tube having a distal outer tube lumen; A proximal outer tube having a proximal outer tube inner cavity and arranged at the proximal side of the distal outer tube; An inner tube having a guidewire lumen through which a guidewire can be inserted, the inner tube being disposed in the lumen of the distal outer tube, and a distal end of the inner tube protruding from a distal end of the distal outer tube; A hand tube having a hand tube inner cavity and arranged at the proximal side of the proximal outer tube; a pressurizer connection portion engaged with the proximal side of the hand tube; and A balloon, wherein the distal end of the balloon is joined to the vicinity of the distal end of the inner tube, the proximal end of the balloon is joined to the distal end of the distal outer tube, and the outer surface of the balloon has one or more protrusions formed integrally with the balloon, A ratio of a length from a distal end of the inner tube to a distal end of the hand tube to a length from a distal end of the inner tube to a proximal end of an exposed portion of the hand tube is greater than 0.23 and less than 0.

29.

2. The balloon catheter according to claim 1, characterized in that: The proximal end of the inner tube forms a guide wire opening between the proximal end of the distal outer tube and the distal end of the proximal outer tube. The ratio of the length from the distal end of the inner tube to the guide wire port to the length from the distal end of the inner tube to the distal end of the hand tube is 0.70 or more and 0.85 or less.

3. The balloon catheter according to claim 2, characterized in that: The ratio of the length from the distal end of the inner tube to the guide wire port to the length from the distal end of the inner tube to the distal end of the hand tube is 0.75 or more and 0.80 or less.

4. The balloon catheter according to claim 1, characterized in that: Also available: The reinforcing body protrudes from the inner cavity of the hand tube and is arranged in at least a part of the inner cavity of the distal outer tube and the inner cavity of the proximal outer tube.

5. The balloon catheter according to claim 4, characterized in that: The protruding length of the reinforcement body from the distal end of the hand tube to the distal end of the reinforcement body is greater than 200 mm.

6. The balloon catheter according to claim 4, characterized in that: A ratio of a protruding length of the reinforcement body from a distal end of the hand tube to a distal end of the reinforcement body to a length from a distal end of the inner tube to a distal end of the hand tube is 0.5 or more and 1 or less.

7. The balloon catheter according to claim 6, characterized in that: A ratio of a protruding length of the reinforcement body from a distal end of the hand tube to a distal end of the reinforcement body to a length from a distal end of the inner tube to a distal end of the hand tube is 0.65 or less.

8. The balloon catheter according to any one of claims 1 to 7, characterized in that: The balloon comprises: a straight tube portion; a distal cone portion located at the distal side of the straight tube portion; a proximal cone portion located at the proximal side of the straight tube portion; a distal sleeve portion located at the distal side of the distal cone portion; and a proximal sleeve portion located at the proximal side of the proximal cone portion. At least a portion between the distal end of the inner tube and the distal end of the distal sleeve portion is provided with a tip portion. The axial length from the distal end of the inner tube to the distal end of the distal tapered portion is 5 mm or more.

9. The balloon catheter according to any one of claims 1 to 7, characterized in that: The balloon comprises: a straight tube portion; a distal cone portion located at the distal side of the straight tube portion; a proximal cone portion located at the proximal side of the straight tube portion; a distal sleeve portion located at the distal side of the distal cone portion; and a proximal sleeve portion located at the proximal side of the proximal cone portion. At least a portion between the distal end of the inner tube and the distal end of the distal sleeve portion is provided with a tip portion. A ratio of an axial length from a distal end of the inner tube to a distal end of the distal tapered portion to an axial length of a straight tube portion of the balloon is 0.4 or more.

10. The balloon catheter according to any one of claims 1 to 7, characterized in that: At least a portion of the surface of the balloon and at least a portion of the surface of the distal outer tube are coated with a hydrophilic coating.

11. The balloon catheter according to claim 10, characterized in that: At least a portion of the surface of the tube at hand is coated with a lubricious coating.

12. The balloon catheter according to claim 10, characterized in that: At least a portion of the surface of the balloon or at least a portion of the surface of the tube at hand is coated with a hydrophobic coating.

13. The balloon catheter according to any one of claims 1 to 7, characterized in that: At least a portion of the surface of the balloon includes a coating of a pharmaceutical agent.

14. The balloon catheter according to any one of claims 1 to 7, characterized in that: The balloon comprises a balloon outer layer located radially outward and a balloon inner layer located radially inward, and a material of the balloon outer layer is different from a material of the balloon inner layer.

Images