Classifications

• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M25/00—Catheters; Hollow probes
  • A61M25/10—Balloon catheters
  • A61M25/1011—Multiple balloon catheters
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61F—FILTERS IMPLANTABLE INTO BLOOD VESSELS; PROSTHESES; DEVICES PROVIDING PATENCY TO, OR PREVENTING COLLAPSING OF, TUBULAR STRUCTURES OF THE BODY, e.g. STENTS; ORTHOPAEDIC, NURSING OR CONTRACEPTIVE DEVICES; FOMENTATION; TREATMENT OR PROTECTION OF EYES OR EARS; BANDAGES, DRESSINGS OR ABSORBENT PADS; FIRST-AID KITS
  • A61F2/00—Filters implantable into blood vessels; Prostheses, i.e. artificial substitutes or replacements for parts of the body; Appliances for connecting them with the body; Devices providing patency to, or preventing collapsing of, tubular structures of the body, e.g. stents
  • A61F2/02—Prostheses implantable into the body
  • A61F2/24—Heart valves ; Vascular valves, e.g. venous valves; Heart implants, e.g. passive devices for improving the function of the native valve or the heart muscle; Transmyocardial revascularisation [TMR] devices; Valves implantable in the body
  • A61F2/2427—Devices for manipulating or deploying heart valves during implantation
  • A61F2/243—Deployment by mechanical expansion
  • A61F2/2433—Deployment by mechanical expansion using balloon catheter
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M25/00—Catheters; Hollow probes
  • A61M25/10—Balloon catheters
  • A61M25/1011—Multiple balloon catheters
  • A61M2025/1013—Multiple balloon catheters with concentrically mounted balloons, e.g. being independently inflatable
• • A—HUMAN NECESSITIES
  • A61—MEDICAL OR VETERINARY SCIENCE; HYGIENE
  • A61M—DEVICES FOR INTRODUCING MEDIA INTO, OR ONTO, THE BODY; DEVICES FOR TRANSDUCING BODY MEDIA OR FOR TAKING MEDIA FROM THE BODY; DEVICES FOR PRODUCING OR ENDING SLEEP OR STUPOR
  • A61M25/00—Catheters; Hollow probes
  • A61M25/10—Balloon catheters
  • A61M25/1006—Balloons formed between concentric tubes

Definitions

• the present invention relates to a balloon catheter, and in particular to a balloon catheter used to treat aortic valve stenosis.
• BAV balloon aortic valvuloplasty
• ECG-synchronized BAVs that use a drive system synchronized with the electrocardiogram
• ECG-synchronized aortic valve expansion systems can expand the aortic valve in sync with physiological rhythms.
• frequent expansion is possible without high-frequency pacing, making it possible to treat patients who cannot undergo conventional BAV treatment, and offering the advantage of significantly improved effectiveness compared to existing aortic valve balloons.
• ECG-gated BAV expands the aortic valve with a balloon frequently (at least six times) and significantly increases the valve orifice area compared to conventional expansion methods, which involve one to three expansions. This has the potential to save patients whose lives could not be saved until now (see Non-Patent Document 1).
• the most serious complication of ECG-gated BAV is air embolism (cerebral infarction) due to balloon rupture. In order to put ECG-gated BAV into practical use, it is necessary to reduce this risk as close to zero as possible.
• the present inventors have already proposed a balloon catheter that includes a shaft, an inner balloon, and an outer balloon (see Patent Document 1).
• the outer balloon is attached to the shaft at the front and rear ends so as to cover the inner balloon, and the radial elongation rate of the outer balloon is smaller than that of the inner balloon, so that the outer balloon does not expand excessively, and the risk of balloon rupture can be avoided, enabling a highly safe treatment.
• the shaft has an inner balloon connecting lumen that communicates from the end face on the rear end side in the longitudinal direction through the inside of the shaft to the inside of the inner balloon, and an outer balloon connecting lumen that communicates with the inside of the outer balloon, and the technology is not related to a balloon catheter having a single expansion lumen.
• a known technique for doubling the balloon in a balloon catheter having a single expansion lumen is a balloon catheter having inner and outer inflatable balloons attached to a catheter shaft, the inner balloon being less elastic than the outer balloon (see Patent Document 2).
• the balloon catheter of Patent Document 2 is a technology premised on being used for a cryoballoon. When such a technology is applied to a BAV, the inner balloon has less elasticity than the outer balloon, and the strength of the outer balloon is insufficient, making it prone to rupture.
• Konishi A “The effect of multiple-inflationballoon aortic valvuloplasty”, Heart and Vessels 2020, 35, 1557-1562
• the present invention provides a balloon catheter having a single expansion lumen,
• the object of the present invention is to provide a balloon catheter capable of preventing the balloon from bursting and having an improved deflation response.
• the double membrane balloon catheter of the present invention is a balloon catheter having a single expansion lumen within the double membrane balloon
• the double membrane balloon consists of an outer balloon and an inner balloon
• the outer balloon and the inner balloon are bonded at the proximal end of the outer balloon to the proximal end of the inner balloon and at the distal end of the outer balloon to the distal end of the inner balloon
• the inner surface of the expansion part of the outer balloon that expands when the double membrane balloon is inflated and the outer surface of the expansion part of the inner balloon are not bonded
• the inner diameter of the outer balloon is larger than the outer diameter of the inner balloon.
• the double-layered membrane of the outer and inner balloons prevents air and other fluids from leaking into the bloodstream even if a hole is made in the surface of the balloon.
• the outer and inner balloons are not bonded to each other at the expansion section, so the balloons are not integrated, and this has the advantage that the inner balloon is not involved in the damage if the outer balloon is damaged.
• the diameters of the outer balloon and the inner balloon are not the same size, and the inner diameter of the outer balloon is larger than the outer diameter of the inner balloon, the contraction force of the inner balloon is improved when it contracts after being expanded, resulting in a balloon with good contraction response.
• the axial length of the outer balloon is longer than the axial length of the inner balloon.
• the contraction response can be improved by increasing the axial length of the outer balloon and decreasing the axial length of the inner balloon.
• the outer balloon is preferably made of a material having a higher durometer hardness than the inner balloon.
• the outer balloon is preferably made of polyether block amide, polyamide, polyurethane, polyethylene, or a mixture of these materials
• the inner balloon is preferably made of polyurethane or a mixture of polyurethane and polyamide or polyether block amide.
• the outer balloon and the inner balloon may have different cross-sectional shapes in part or all of the longitudinal direction. Since the outer balloon is pressed against the inner balloon by external pressure (atmospheric pressure or intracardiac blood pressure), the outer balloon and the inner balloon each have a different shape, and if the outer balloon is made of a hard material, it will follow the shape of the inner balloon during the expansion process and eventually settle into the shape of the outer balloon. In this case, for example, if the outer balloon is approximately cylindrical in cross-sectional shape, the inner balloon will also be approximately cylindrical at the end of the expansion phase.
• the outer balloon ellipsoidal or cylindrical and the inner balloon an hourglass, dumbbell, triangular prism or other polygonal prism
• the outer balloon expands to follow the shape of the inner balloon during the initial to middle stages of expansion, thereby strengthening the fixing force to the affected area.
• the middle to the final stage of expansion maximum expansion state
• the outer balloon is already in contact with the affected area and is unlikely to slip, so effective expansion of the affected area is required rather than strengthening the fixation force.
• the outer balloon is made of a material with a higher durometer hardness than the inner balloon, at this stage, the inner balloon expands following the shape of the outer balloon. In this way, it is possible to achieve both fixation force to the affected area and effective expansion of the affected area.
• the gap between the inner surface of the expansion part of the outer balloon and the outer surface of the expansion part of the inner balloon may be filled with less than 0.1 mL of gas.
• the aortic valve expansion system of the present invention comprises any one of the above double membrane balloon catheters and a drive unit that discharges and draws gas into the expansion lumen of the double membrane balloon catheter in synchronization with an electrocardiogram, and the expansion lumen automatically repeats contraction and expansion in synchronization with the electrocardiogram. Since the drive unit discharges and draws gas into the expansion lumen of the double membrane balloon catheter in synchronization with an electrocardiogram, frequent expansion is possible without the need for high tachycardia pacing, and treatment can be performed on patients who could not be treated in the past. In addition, by providing a double membrane balloon catheter, the risk of balloon rupture can be reduced while the contraction response can be improved, realizing a system with high safety and effectiveness.
• the gas carbon dioxide gas is preferably used, but other gases may be used as well, and fluids other than gases may also be used.
• the double membrane balloon catheter of the present invention has the effect of preventing balloon rupture and improving deflation response in a balloon catheter with a single expansion lumen.
• FIG. 1 is an explanatory diagram of a double membrane balloon catheter according to a first embodiment of the present invention.
• Image of contraction of the double membrane balloon catheter of Example 1 Functional block diagram of the aortic valve expansion system according to the first embodiment Image of the double membrane balloon catheter in use according to the first embodiment
• Fig. 1 shows a cross-sectional image of the double membrane balloon catheter of Example 1.
• the double membrane balloon catheter 1 is composed of an outer balloon 2, an inner balloon 3, an outer tube 4, an inner tube 5, and a gripping portion 6.
• the inner tube 5 is inserted into the outer tube 4, and a lumen 7a is formed between the outer tube 4 and the inner tube 5.
• a lumen 7b is formed in the lumen of the inner tube 5, and a guide wire 14 (see Fig. 5) can be inserted therethrough.
• An outer balloon 2 and an inner balloon 3 are provided on the distal end sides of the outer tube 4 and the inner tube 5, and a gripping portion 6 is provided on the proximal end sides of the outer tube 4 and the inner tube 5.
• a through hole 61 communicating with the lumen 7a is provided in the gripping portion 6, and carbon dioxide gas is sucked in and exhausted to the expansion lumen 8 through the through hole 61 and the lumen 7a.
• FIG. 2 shows an explanatory diagram of the double-membrane balloon catheter of Example 1.
• the inner balloon 3 is adhesively attached to the inner tube 5
• the outer balloon 2 is adhesively attached to the inner balloon 3.
• the inner balloon 3 is adhesively attached to the outer tube 4
• the outer balloon 2 is adhesively attached to the inner balloon 3.
• the reinforcing section 51 partially reinforces the inner tube 5 located in the expansion section 11, and prevents the inner tube from buckling due to the compressive force of the inner tube that occurs as a result of the balloon deformation during balloon expansion.
• the reinforcing section 51 is provided with a marker (not shown), making it easy to check under X-ray fluoroscopy.
• the outer balloon 2 is made of polyether block amide, and the inner balloon 3 is made of polyurethane.
• the outer balloon 2 is made of a material having a higher durometer hardness than the inner balloon 3, the outer balloon 2 having a durometer hardness of 72D and the inner balloon 3 having a durometer hardness of 80A.
• the outer balloon 2 has an ellipsoidal shape, but is not limited to this shape and may have a polygonal shape, such as an approximately triangular prism shape.
• the inner balloon 3 unlike the outer balloon 2, has an hourglass shape with a depression in the approximate center in the longitudinal direction. The hourglass shape improves the fixing force to the heart valve.
• the inner balloon 3 may have a shape without a depression in the longitudinal center, for example, an ellipsoidal shape.
• the maximum outer diameter ⁇ 2 of the inner balloon 3 is set smaller than the maximum inner diameter ⁇ 1 of the outer balloon 2.
• the length L2 of the inner balloon 3 in the expansion section 11 is set shorter than the length L1 of the outer balloon 2.
• the adhesive structure of the outer balloon 2 and the inner balloon 3 will be explained.
• the outer balloon 2 and the inner balloon 3 are placed over a core (not shown) in the order of the inner balloon 3 and the outer balloon 2, and are then adhered at the adhesive parts (12a, 12b) at both ends, after which the core is removed. Therefore, the air between the outer balloon 2 and the inner balloon 3 is removed, but a vacuum is not created, and a gap 9 is formed between the outer balloon 2 and the inner balloon 3.
• the sizes of the outer balloon 2 and the inner balloon 3 before being assembled to the outer tube 4 and the inner tube 5 are preferably such that the inner diameter of the outer balloon 2 is 15 to 30 mm, the outer diameter of the inner balloon 3 is 10.5 to 27 mm, the axial length of the outer balloon 2 is 30 to 50 mm, and the axial length of the inner balloon is 22.5 to 45 mm, and the ratio of the outer diameter of the inner balloon 3 to the inner diameter of the outer balloon 2 is 70% to 90% and the axial length of the inner balloon 3 to the axial length of the outer balloon 2 is 75% to 90%.
• the sizes of the outer balloon 2 and the inner balloon 3 before being assembled to the outer tube 4 and the inner tube 5 are such that the inner diameter of the outer balloon 2 is 20 mm, the outer diameter of the inner balloon 3 is 14 mm, the axial length of the outer balloon 2 is 40 mm, and the axial length of the inner balloon is 30 mm.
• the sizes of the outer balloon 2 and the inner balloon 3 here exclude the adhesive parts 12a and 12b. Under these conditions, a test was carried out to measure the amount of gas present between the outer balloon 2 and the inner balloon 3.
• FIG. 6 shows an explanatory diagram of the gas measurement test between the inner and outer balloons.
• the double membrane balloon catheter 1 is not shown in detail in FIG. 6.
• the water tank 15 was filled with water 16, and the beaker 17 was submerged in the water tank 15 while being in a state where it does not contain air.
• the expansion lumen 8 of the double membrane balloon catheter 1 was filled with water.
• the double membrane balloon catheter 1 was submerged in the water tank 15, the outer balloon 2 and the inner balloon 3 were covered with the beaker 17, and the needle 18 was inserted into the outer balloon 2 and the inner balloon 3 to open a hole.
• the outer balloon 2 was pressed, and the gas 7 present in the gap 9 was squeezed out and stored in the beaker 17, and the gas was collected in a 1 mL syringe 19 to measure the amount of gas. As a result, less than 0.1 mL of gas was obtained. From the above, it was found that the gap between the inner surface of the expansion portion 11 of the outer balloon 2 and the outer surface of the expansion portion 11 of the inner balloon 3 was filled with less than 0.1 mL of gas.
• the inner balloon 3 is made with a smaller diameter than the outer balloon 2, so when the inner balloon 3 is attached to the core body, it is placed over the core body while a stretching force is being applied. This improves the contraction response when the balloon is deflated. Also, since the outer balloon 2 is pressed against the inner balloon 3 by external pressure, if the outer balloon 2 is made of a hard material, it will follow the shape of the inner balloon 3 during the expansion process and eventually settle into the shape of the outer balloon 2.
• Fig. 3 is a contraction image of the double membrane balloon catheter of Example 1, (1) shows a state where wrinkles have occurred in the outer balloon, and (2) shows a state where wrinkles have occurred in the inner balloon.
• Fig. 7 is a contraction image of the balloon catheter of the comparative example. Note that the reinforcing part 51 is not shown in Fig. 3. In the balloon catheter of the comparative example shown in Fig. 7, the outer balloon 2 and the inner balloon 3 are bonded over almost the entire surface of the expansion section 11a.
• the outer balloon 2 and the inner balloon 3 that are integrated together will bend at the same location as shown in part P3 in Fig. 7.
• the outer balloon 2 and the inner balloon 3 that are integrated together are prone to damage at their tops due to their thickness.
• the inner balloon 3 will be caught up in the damage.
• FIG. 4 shows a functional block diagram of the aortic valve expansion system of the first embodiment.
• the aortic valve expansion system 10 is composed of a double membrane balloon catheter 1 and a drive unit 13, and the expansion lumen 8 automatically repeats contraction and expansion in synchronization with an electrocardiogram.
• the drive unit 13 discharges and draws carbon dioxide gas 7 into the expansion lumen 8 of the double membrane balloon catheter 1 in synchronization with the electrocardiogram.
• the drive unit 13 is connected to an electrocardiogram data acquisition means and an electrocardiogram synchronization calculation means, not shown.
• the electrocardiogram data acquisition means acquires electrocardiogram data of the patient, and the electrocardiogram synchronization calculation means calculates data for electrocardiogram synchronization based on the electrocardiogram data acquired by the electrocardiogram data acquisition means.
• the drive unit 13 is driven in synchronization with the electrocardiogram based on the calculated data for electrocardiogram synchronization.
• Fig. 5 shows an image of the use of the double membrane balloon catheter of Example 1. As shown in Fig. 5, the double membrane balloon catheter 1 is inserted from the ascending aorta 21 of the heart 20 into the left ventricle 23 with the guide wire 14, and then guides the expansion part 11 to the position of the aortic valve 22 to perform expansion and contraction.
• the aortic valve expansion system 10 does not require high-speed tachycardia pacing and can be expanded frequently, so in addition to being able to treat patients who could not be treated previously, it also has advantages such as effectiveness, safety, and simplicity of procedure.
• the aortic valve expansion system 10 of this embodiment was used to expand 500 times in a non-clinical trial environment simulating a human, and the outer balloon 2 and inner balloon 3 did not burst, and the usefulness of the system was confirmed, including a reduction in the aortic valve pressure difference.
• the present invention is useful as a balloon catheter for treating heart disease, etc.

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Citations (3)

• 2023
  • 2023-03-20 JP JP2025507976A patent/JPWO2024195004A1/ja active Pending
  • 2023-03-20 CN CN202380096121.8A patent/CN120936402A/zh active Pending
  • 2023-03-20 EP EP23928587.7A patent/EP4678217A1/en active Pending
  • 2023-03-20 WO PCT/JP2023/010980 patent/WO2024195004A1/ja not_active Ceased

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