Medical system and approach method

Abstract

The present invention provides a medical system and an approach method that make it possible to safely and easily approach the pericardial cavity.　A medical system (10) comprises: a long, flexible guiding catheter (30); a long puncture implement (40) which is insertable into the guiding catheter (30), which is provided with puncture needle (42) at the tip end part thereof, and which is provided with a lumen (45) that extends from a base end part thereof to the tip end part thereof, and a tip end opening (46) that is in communication with the lumen (45) at the tip end part; a biasing implement (50) which is provided with a moving part (53) that is movable in order to apply biasing force in the tip end direction to a material passing through the lumen (45), and a biasing part (57) that biases the moving part (53); and a releasable stopper (55) which is capable of fixing the moving part (53) at a prescribed position.

Description

Healthcare systems and approaches

[0001] The present invention relates to a medical system and method for approaching the pericardial cavity via a blood vessel.

[0002] In recent years, treatments have been performed to perform arrhythmia ablation, drain body fluids from the pericardial cavity, or supply drugs through the pericardial cavity located between two pericardiums that constitute the pericardium that covers the myocardial tissue. For such treatments, for example, Patent Literature 1 discloses a method and a device for approaching the pericardial cavity from the surface of the patient's body.

[0003] Special table 2017-506560 publication

[0004] Because the two pericardiums are partially in close contact, the space within the pericardial cavity is extremely narrow. Therefore, in order to approach the pericardial cavity from the surface of the body, it is necessary to widen the gap between the two pericardiums, which makes the procedure complicated. In addition, there is a risk of inserting the needle into an unintended location within the heart, making it less safe.

[0005] The present invention has been made to solve the above-mentioned problems, and an object of the present invention is to provide a medical system and an approach method that enable safe and easy approach to the pericardial cavity.

[0006] The above object is achieved by the invention described in (1) below. (1) A medical system according to the present invention is characterized by comprising: a long, flexible catheter; a long puncture device that is insertable into the catheter and has a puncture needle at its distal end, a lumen extending from its base end to its distal end, and a distal opening at the distal end that communicates with the lumen; a biasing device that has a movable portion that is movable to apply a biasing force toward the distal end to a material passing through the lumen and a biasing portion that biases the movable portion; and a releasable stopper that can fix the movable portion at a predetermined position.

[0007] In the medical system described in (1) above, when the stopper is released, the moving part applies a biasing force to the material passing through the lumen of the puncture instrument, pushing it out from the tip of the puncture needle. Therefore, the medical system punctures a blood vessel wall or a blood vessel wall from within a cardiac cavity or a blood vessel with the puncture instrument, causing the material passing through the lumen of the puncture instrument to reach the pericardial cavity. Therefore, by observing the material reaching the pericardial cavity through the lumen, the pericardial cavity can be safely and easily approached.

[0008] (2) The medical system described in (1) above may further include a visualization means having ultrasound contrast or X-ray contrast as a material passing through the lumen, whereby the medical system allows the visualization means passing through the lumen and reaching the pericardial cavity to be observed by an imaging device using ultrasound or X-ray.

[0009] (3) In the medical system described in (2) above, the visualization means may be a wire, whereby the medical system allows the wire passing through the lumen and reaching the pericardial cavity to be observed by an imaging device.

[0010] (4) In the medical system described in (2) above, the visualization means may be a liquid containing a plurality of microbubbles, thereby enabling the medical system to observe, with an imaging device, the microbubbles that pass through the lumen and reach the pericardial cavity.

[0011] (5) In the medical system according to any one of (1) to (4) above, the biasing device may be detachable from the puncture device. This allows the biasing device to be attached to the puncture device when needed and detached from the puncture device when not needed, improving the operability of the puncture device.

[0012] (6) In the medical system according to any one of (1) to (5) above, the biasing means may have a wire fixing portion capable of fixing the wire to the moving portion, thereby making it easy to fix the wire to the moving portion and move the wire together with the moving portion.

[0013] (7) An approach method according to the present invention is a method for approaching the pericardial cavity from inside a cardiac cavity or a blood vessel, comprising: preparing a long, flexible catheter; and a long puncture device that can be inserted into the catheter and has a puncture needle at its tip, a lumen extending from its base end to its tip end, and a tip opening at the tip end that communicates with the lumen; inserting the catheter into the blood vessel; carrying the catheter to a puncture position within the cardiac cavity or blood vessel where the puncture device inserted into the catheter can puncture toward the pericardial cavity; and pressing the tip end, located at the tip of the catheter, against the inner wall of the heart or blood vessel toward the pericardial cavity, thereby tenting. The catheter is placed in a tenting state, and the pressed cardiac or vascular wall is imaged with an imaging device. A visualization means having ultrasound or X-ray contrast properties and inserted into the lumen is biased in a direction to push the visualization means out of the lumen through the distal opening of the puncture device while restricting movement of the visualization means outward from the distal opening, thereby entering a puncture-ready state. In the tenting state and the puncture-ready state, the puncture needle is used to puncture the cardiac or vascular wall through the lumen of the catheter, and the restriction on movement of the visualization means is released. The biased visualization means is then inserted into the pericardial cavity through the distal opening of the puncture device while being imaged with the imaging device. This approach method thus allows the visualization means to reach the pericardial cavity by puncturing the cardiac or vascular wall with the puncture device from within the cardiac cavity or blood vessel, passing through the lumen of the puncture device. Therefore, this approach method allows the puncture device and visualization means to safely and easily approach the pericardial cavity by observing the visualization means with the imaging device.

[0014] 1 is a plan view showing a medical system according to a first embodiment; FIG. 2 is a cross-sectional view showing the medical system according to the first embodiment; FIG. 3 is a schematic view showing a cross section of a living body, a medical system, and an imaging device in plan; FIG. 4 is a cross-sectional view taken along line A-A in FIG. 3; FIG. 5 is a cross-sectional view illustrating a usage example of the medical system according to the first embodiment, where (A) shows a state in which a blood vessel wall is tented by a guiding catheter, and (B) shows a state in which an assembly is inserted into the guiding catheter; FIG. 6 is a cross-sectional view illustrating a usage example of the medical system according to the first embodiment, where (A) shows a state in which the moving unit is made movable by the release unit, and (B) shows a state in which the blood vessel wall is punctured by the puncture device and the wire has reached the pericardial cavity; FIG. 7 is a cross-sectional view illustrating a usage example of the medical system according to the first embodiment, where (A) shows a state in which the blood vessel wall is punctured by the puncture device and the wire is withdrawn, and (B) shows a state in which the blood vessel wall is punctured by the puncture device and the puncture device is withdrawn; FIG. 8 is a flowchart illustrating an approach method using the medical system according to the first embodiment. 10A and 10B are cross-sectional views illustrating an example of use of the medical system according to the second embodiment, showing a state in which the vascular wall is tented by the guiding catheter and a state in which the movable unit is made movable by the release unit. 10B are cross-sectional views illustrating an example of use of the medical system according to the second embodiment, showing a state in which the vascular wall is punctured by the puncture device and the wire reaches the pericardial cavity. 10C are cross-sectional views illustrating a modified example of the medical system according to the first embodiment, showing a state in which the vascular wall is tented by the guiding catheter and a state in which the vascular wall is punctured by the puncture device and the wire reaches the pericardial cavity.

[0015] Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that dimensions in the drawings may be exaggerated for convenience of explanation and may differ from actual dimensions. Furthermore, in this specification and the drawings, components having substantially the same functions are designated by the same reference numerals, and redundant description will be omitted. In this specification, the side inserted into a lumen will be referred to as the "distal side," and the side near the operator will be referred to as the "proximal side." <First embodiment>

[0016] As shown in Figures 1 and 2, a medical system 10 according to a first embodiment of the present invention is a system for approaching a pericardial cavity 305 between two pericardiums 303 constituting a pericardial sac covering a myocardium 304 via a blood vessel. The medical system 10 includes a backup catheter 20, a guiding catheter (catheter) 30, a puncture device 40, a biasing device 50, and a wire 70 (visualization means). As shown in Figure 3, the medical system 10 is used together with an imaging device 90.

[0017] 1 to 4, the backup catheter 20 is used to hold the guiding catheter 30 near the target location in the blood vessel or heart where puncture is to be performed. The backup catheter 20 is a known catheter, but may also be a dedicated catheter with a bent tip, for example.

[0018] The guiding catheter 30 is used to guide the puncture device 40 to the vicinity of the target location in the blood vessel or heart where puncture is to be performed. The guiding catheter 30 is a known catheter, but may also be a dedicated catheter.

[0019] The imaging device 90 is a device that is percutaneously inserted into a blood vessel or the heart together with the backup catheter 20, the guiding catheter 30, the puncture device 40, the wire 70, etc., and acquires cross-sectional images by intravascular ultrasound (IVUS). The imaging device 90 can be used to visually recognize the position of the medical system 10 inside the body. The imaging device 90 may also be an X-ray imaging device that can capture cross-sectional images of a living body using X-rays from outside the body.

[0020] The puncture instrument 40 is an instrument that punctures the myocardium 304 from the cardiac chamber 306 to approach the pericardial cavity 305. The puncture instrument 40 includes a long, hollow shaft 41 with a puncture needle 42 at its tip, and a hub 43 to which the proximal end of the shaft 41 is fixed. The puncture needle 42 is formed, for example, by cutting the tip of the shaft 41 obliquely. The shape of the puncture needle 42 is not particularly limited as long as it can puncture a living body, and may be, for example, a cone, a knife-shaped flat plate, or a shovel-shaped curved plate. The cross-sectional shape of the puncture needle 42 does not have to be circular. The puncture needle 42 may also be an electrode capable of emitting energy such as current or heat. In this case, the puncture needle 42 does not have to be sharp. The hub 43 has a male thread-shaped protrusion 44 on its outer periphery. The shaft 41 and hub 43 are formed with a lumen 45 that penetrates from the distal end to the proximal end of the puncture instrument 40. The puncture device 40 has a tip opening 46 at its tip that communicates with the lumen 45. The tip opening 46 is formed on the inclined tip surface at the tip of the puncture device 40 where the puncture needle 42 is formed.

[0021] The material constituting the shaft 41 is preferably somewhat hard, and suitable materials include metals such as stainless steel, tantalum, titanium, platinum, gold, and tungsten, polyolefins such as polyethylene and polypropylene, polyesters such as polyamide and polyethylene terephthalate, fluorine-based polymers such as PTFE (polytetrafluoroethylene) and ETFE (ethylene-tetrafluoroethylene copolymer), PEEK (polyether ether ketone), and polyimide.

[0022] The biasing device 50 has a connecting portion 51 that can be connected to the hub 43, a housing 52 arranged on the base end side of the connecting portion 51, a moving portion 53 that can move axially relative to the housing 52, a wire fixing portion 54 that can fix the wire 70 to the moving portion 53, a stopper 55 that releasably stops the moving portion 53 relative to the housing 52 at a predetermined axial position, a release portion 56 that releases the stopper 55, and a biasing portion 57 that biases the moving portion 53 toward the tip relative to the housing 52.

[0023] The connecting portion 51 is cylindrical and is connected to the tip of the housing 52 so as to be rotatable in the circumferential direction relative to the housing 52. The outer peripheral surface of the connecting portion 51 is the portion that the surgeon rotates to connect the connecting portion 51 to the hub 43. The connecting portion 51 has, on its inner peripheral surface, a female thread 58 that can be threaded onto the protrusion 44 on the outer peripheral surface of the hub 43.

[0024] The housing 52 is connected to the base end of the connecting portion 51. A through hole 59 is formed in the housing 52, through which the wire 70 can pass. A part of the through hole 59 forms a rail 60 on which the moving portion 53 is disposed and which is movable in the axial direction.

[0025] The moving section 53 is a section to which the wire 70 is fixed and which moves together with the wire 70. The moving section 53 is housed on a rail 60 of the housing 52 and is movable in the axial direction along the rail 60. The moving section 53 has a fixing hole 61 that penetrates in the axial direction and a fixing screw hole 62 that is a hole that abuts against the fixing hole 61 perpendicular to the axial direction. The wire 70 can pass through the fixing hole 61. A fixing screw 63 formed in the wire fixing section 54 can be threaded into the fixing screw hole 62. The fixing screw 63 can enter the fixing hole 61 from the side by the surgeon rotating the screw head 64. Therefore, the fixing screw 63 presses the wire 70 passing through the fixing hole 61 against the inner wall surface of the fixing hole 61, thereby fixing the wire 70 to the moving section 53.

[0026] The biasing portion 57 is disposed on the rail 60 of the through-hole 59 of the housing 52 closer to the base end than the moving portion 53. The biasing portion 57 biases the moving portion 53 toward the tip end relative to the housing 52. The biasing portion 57 is, for example, a coil spring, but may also be an elastic body such as rubber.

[0027] The stopper 55 releasably stops the moving unit 53, which has moved along the rail 60 relative to the housing 52 in the proximal direction against the biasing force of the biasing unit 57, at a predetermined position. The stopper 55 has, for example, a hook 66 that protrudes from the moving unit 53, is flexible in a radial direction perpendicular to the axial direction, and can hook onto an engaging unit 65 of the housing 52. The engaging unit 65 is formed in a hole that penetrates from the inner surface of the rail 60 of the housing 52 to the outer surface perpendicular to the axial direction. Note that the hook 66 may be formed on the housing 52 side, and the engaging unit 65 may be formed on the moving unit 53 side. The configuration of the stopper 55 is not particularly limited as long as it can releasably stop the moving unit 53 at a predetermined position relative to the housing 52.

[0028] The release portion 56 is a component that releases the state in which the moving portion 53 is stopped relative to the housing 52 by the stopper 55. The release portion 56 is, for example, connected to the housing 52 so as to be movable in a direction perpendicular to the axial direction but not in the axial direction. For example, the release portion 56 is slidably disposed in a groove formed in the outer peripheral surface of the housing 52 in a direction perpendicular to the axial direction. The release portion 56 has a protrusion 67 that can enter the engaging portion 65 from the outside in the radial direction. The protrusion 67 can push the hook 66 engaged with the engaging portion 65 out of the engaging portion 65, thereby releasing the engagement. The configuration of the release portion 56 is not particularly limited as long as it can release the state in which the moving portion 53 is stopped relative to the housing 52.

[0029] Wire 70 is a long, flexible member, and is formed with a length and outer diameter that allows it to pass through lumen 45 of puncture device 40. Wire 70 has ultrasound and / or X-ray contrast properties so that it can be imaged by imaging device 90. Wire 70 may also be a guide wire that can guide other devices.

[0030] The material constituting the wire 70 is preferably flexible and somewhat hard, and examples of suitable materials include metals such as stainless steel, tantalum, titanium, platinum, gold, and tungsten; shape-memory alloys such as Ni-Ti alloys that have a shape-memory effect or superelasticity; polyolefins such as polyethylene and polypropylene; polyesters such as polyamide and polyethylene terephthalate; fluorine-based polymers such as PTFE (polytetrafluoroethylene) and ETFE (ethylene-tetrafluoroethylene copolymer); PEEK (polyether ether ketone); and polyimides. At least a portion of the wire 70 (e.g., near the tip) may contain an X-ray contrast material. The X-ray contrast material is preferably formed from at least one metal or an alloy of two or more metals selected from the group consisting of gold, platinum, iridium, tungsten, or alloys thereof, and silver-palladium alloys.

[0031] Next, a usage example of the medical system 10 according to the first embodiment will be described with reference to the flowchart shown in FIG.

[0032] 3, 4, and 5A, the surgeon percutaneously inserts the imaging device 90 and the backup catheter 20 into a blood vessel (step S1). While checking the position of the backup catheter 20 with the imaging device 90, the surgeon guides the tip of the backup catheter 20 through, for example, the inferior vena cava 300 to a cardiac chamber 306 (e.g., the right atrium 301) or a blood vessel (e.g., the superior vena cava 302). Next, the surgeon inserts the guiding catheter 30 into the lumen of the backup catheter 20, causing the tip of the guiding catheter 30 to protrude from the tip of the backup catheter 20. While checking the position of the guiding catheter 30 with the imaging device 90, the surgeon guides the tip of the guiding catheter 30 to reach a predetermined position (step S2). At this time, the surgeon positions the tip of the guiding catheter 30 at a puncture position P in the cardiac chamber 306 or the blood vessel, where the puncture device 40 can approach the pericardial cavity 305 located between two pericardiums 303 constituting the pericardium. The puncture position P is preferably a position where the pericardial cavity 305, which is the target of the approach, is wide and easy to approach with the puncture instrument 40. As an example, the target pericardial cavity 305 is preferably between the superior vena cava 302 and the right atrial appendage 307. In this case, the puncture position P is located in the superior vena cava 302. Note that the pericardial cavity 305, which is the target of the approach, is not particularly limited. Therefore, the puncture position P may be located in the heart rather than in a blood vessel.

[0033] Next, the surgeon tent- izes the heart wall by pressing it toward the pericardial cavity 305 with the tip of the guiding catheter 30 at the puncture position P (step S3). As a result, the heart wall generates a repulsive force and is locally pressed in (tented state).

[0034] Next, the surgeon assembles the puncture instrument 40, the biasing instrument 50, and the wire 70, and inserts the puncture instrument 40 and the wire 70 into the lumen of the guiding catheter 30 (step S4). In the assembled state, the female thread 58 of the connecting portion 51 of the biasing instrument 50 is threaded onto the protrusion 44 of the hub 43 of the puncture instrument 40, connecting the biasing instrument 50 to the puncture instrument 40. Furthermore, the moving portion 53 of the puncture instrument 40 moves toward the proximal end relative to the housing 52, and the hook 66 of the stopper 55 is caught on the engaging portion 65 of the housing 52. Inside the housing 52, the biasing portion 57 is contracted in the axial direction on the proximal side of the moving portion 53. The wire 70 passes through the lumen 45 of the puncture instrument 40 and the through-hole 59 and fixing hole 61 of the biasing instrument 50. Wire 70 is fixed to moving section 53 by wire fixing section 54, in which fixing screws 63 are threaded into fixing screw holes 62. The tip of wire 70 is positioned at a position that is approximately the same as the tip of puncture device 40, or at a position slightly closer to the proximal end than the tip of puncture device 40. To enable the surgeon to easily identify the appropriate position of wire 70, an identification marker 71 (see FIG. 1 ) of a different color from the surrounding area may be placed on the surface of wire 70 that is aligned with a specific position (e.g., the proximal end position) of puncture device 40.

[0035] Instead of inserting the puncture device 40 and the wire 70 into the lumen of the guiding catheter 30 in a state in which the puncture device 40, the biasing device 50, and the wire 70 are combined, the surgeon may insert the guiding catheter 30 into the lumen of the backup catheter 20, insert the puncture device 40 alone into the lumen of the guiding catheter 30, and then insert the wire 70, which is a combination of the biasing device 50 and the wire 70, into the lumen 45 of the puncture device 40. In this case, it is preferable that the wire 70 is fixed at an appropriate position relative to the biasing device 50 so that the position of the tip of the wire 70 relative to the tip of the puncture device 40 is appropriate.

[0036] As shown in Fig. 5(B), the surgeon positions the assembled puncture device 40 and the tip of the wire 70 near the puncture position P in the lumen of the guiding catheter 30. Next, while capturing an image of the tented inner wall of the blood vessel or the inner wall of the heart with the imaging device 90, the surgeon operates the release unit 56 to release the stopper 55 as shown in Fig. 6(A) (step S5). This disengages the hook 66 from the engagement unit 65, and the moving unit 53 is urged toward the tip by the urging unit 57, thereby preparing for puncture. As a result, the wire 70, which is fixed to the moving unit 53 by the fixing unit, is urged in a direction to be pushed out from the tip of the puncture needle 42 and hits the inner wall of the blood vessel or the inner wall of the heart.

[0037] With the guiding catheter 30 tenting the inner wall of the blood vessel or the heart and the wire 70 biased by the biasing device 50, the surgeon operates the puncture device 40 to move it toward the distal end, thereby puncturing the inner wall of the blood vessel or the heart with the puncture needle 42 (step S6). As shown in Fig. 6(B) , as soon as the puncture needle 42 reaches the pericardial cavity 305 together with the distal opening 46, the wire 70 biased by the biasing device 50 protrudes outward (in the distal direction) from the lumen 45 of the puncture device 40 through the distal opening 46 and reaches the pericardial cavity 305. When the wire 70 reaches the pericardial cavity 305, the biasing force of the biasing device 57 moves the moving part 53 toward the distal end within the housing 52 of the biasing device 50. The surgeon can easily confirm in real time that the wire 70 has reached the pericardial cavity 305 using the image captured by the imaging device 90, and can stop the movement of the puncture instrument 40 toward the distal end (step S7). That is, the surgeon can immediately recognize that the distal opening 46 of the puncture instrument 40 has reached the pericardial cavity 305, and can stop the advancement of the puncture needle 42 (puncture operation). This prevents the puncture needle 42 from advancing too far, which could result in penetration of the outer pericardium 303 or the distal opening 46 becoming embedded in the adjacent myocardium (right auricle 305), thereby enabling a safe and easy approach to the pericardial cavity 305. Note that if the wire 70 is radiopaque, the surgeon may confirm that the wire 70 has reached the pericardial cavity 305 using the image captured by the X-ray imaging device 90. The advancement of the wire 70 fixed to the moving part 53 by the wire fixing part 54 is automatically stopped after reaching the pericardial cavity 305 by the moving part 53 abutting the distal end of the housing 52. This prevents the wire 70 from breaking through the outer pericardium 303.

[0038] Next, as shown in Fig. 7(A), the surgeon removes the wire 70 together with the biasing instrument 50, leaving the puncture instrument 40 in the pericardial cavity 305. This allows the lumen 45 of the puncture instrument 40 to be used to administer a drug into the pericardial cavity 305, insert a therapeutic instrument, or drain bodily fluids. Alternatively, as shown in Fig. 7(B), the surgeon may remove the puncture instrument 40 and the wire 70 without removing the wire 70, and use the wire 70 as a guide wire. For example, the surgeon can insert a therapeutic instrument into the pericardial cavity 305 along the wire 70.

[0039] Alternatively, the surgeon may puncture the inner wall of the blood vessel or the inner wall of the heart with the puncture needle 42 at the puncture position P, and then pass the tip of the guiding catheter 30 through the hole formed by the puncture to reach the pericardial cavity 305. In this case, after removing the puncture instrument 40, the surgeon can use the inner cavity of the guiding catheter 30 to administer a drug into the pericardial cavity 305, insert a treatment instrument, or drain body fluids.

[0040] As described above, the medical system 10 according to the first embodiment includes the flexible, long guiding catheter 30, the long puncture device 40 that is insertable into the guiding catheter 30 and has the puncture needle 42 at its distal end, the lumen 45 extending from the base end to the distal end, and the distal opening 46 that communicates with the lumen 45 at its distal end, the biasing device 50 that has the movable part 53 and the biasing part 57 that biases the movable part 53 so as to apply a biasing force toward the distal end to material passing through the lumen 45, and the releasable stopper 55 that can fix the movable part 53 at a predetermined position. Thus, when the stopper 55 is released, the medical system 10 can cause the movable part 53 to apply a biasing force to the material passing through the lumen 45 of the puncture device 40, thereby pushing the material out through the distal opening 46. Therefore, the medical system 10 can puncture the blood vessel wall or blood vessel wall from within the cardiac cavity 306 or within the blood vessel using the puncture device 40, allowing material passing through the lumen 45 of the puncture device 40 to reach the pericardial cavity 305.By observing the material reaching the pericardial cavity 305 through the lumen 45, the puncture device 40 and wire 70 can safely and easily approach the pericardial cavity 305.

[0041] The medical system 10 further includes a visualization means having ultrasound contrast or X-ray contrast as a material passing through the lumen 45. This allows the medical system 10 to observe the visualization means passing through the lumen 45 and reaching the pericardial cavity 305 with an imaging device 90 using ultrasound or X-ray.

[0042] The visualization means is the wire 70. This allows the medical system 10 to use the imaging device 90 to observe the wire 70 passing through the lumen 45 and reaching the pericardial cavity 305.

[0043] The biasing device 50 is detachable from the puncture device 40. This allows the biasing device 50 to be attached to the puncture device 40 when needed and detached from the puncture device 40 when not needed, improving the operability of the puncture device 40.

[0044] The biasing means has a wire fixing portion 54 that can fix the wire 70 to the moving portion 53. This makes it easy for the medical system 10 to fix the wire 70 to the moving portion 53 and move it together with the moving portion 53.

[0045] The approach method in this embodiment is a method for approaching the pericardial cavity 305 from within the cardiac chamber 306 or the blood vessel, and includes preparing a long, flexible guiding catheter 30 and a long puncture device 40 that can be inserted into the guiding catheter 30 and has a puncture needle 42 at its tip, a lumen 45 extending from the base end to the tip end, and a tip opening 46 that communicates with the lumen 46 at the tip end, inserting the guiding catheter 30 into the blood vessel, and carrying the guiding catheter 30 to a puncture position P in the cardiac chamber 306 or the blood vessel where the puncture device 40 inserted into the guiding catheter 30 can puncture the pericardial cavity 305 (step S2), and at the puncture position P, the tip end located at the tip of the guiding catheter 30 is inserted into the endocardial cavity 305. The cardiac wall or the blood vessel inner wall is pressed against the pericardial cavity 305 to create a tenting state (step S3), and the pressed cardiac wall or blood vessel inner wall is imaged by the imaging device 90. At the same time, the visualization means having ultrasound contrast or X-ray contrast inserted into the lumen 45 is urged in a direction of pushing it out of the lumen 45 from the tip opening 46 of the puncture instrument 40 while restricting the movement of the visualization means outward from the tip opening 56, thereby creating a puncture-prepared state (step S5). In the tenting state and puncture-prepared state, the puncture needle 42 punctures the cardiac wall or blood vessel wall through the lumen of the guiding catheter 30, releasing the restriction on the movement of the visualization means. The urged visualization means is inserted into the pericardial cavity 305 through the tip opening 46 of the puncture instrument 40 while being imaged by the imaging device 90 (step S6). As a result, in this approach method, by puncturing the heart wall or blood vessel wall from the cardiac cavity 306 with the puncture device 40, the visualization means passing through the lumen 45 of the puncture device 40 can reach the pericardial cavity 305. Therefore, in this approach method, by observing the visualization means with the imaging device 90, the puncture device 40 and the visualization means can safely and easily approach the pericardial cavity 305. <Second Embodiment>

[0046] 9A, the medical system 10 according to the second embodiment differs from the first embodiment in that it uses microbubbles 120 as the visualization means instead of wires 70. The backup catheter 20, guiding catheter 30, and puncture device 40 in the second embodiment are the same as those in the first embodiment.

[0047] Microbubbles 120, which are visualization means, are provided in a mixed state with a liquid by a syringe 100. The syringe 100 has an outer cylinder 101 that contains a liquid containing microbubbles 120, a cylindrical tip 102 that is located distal to the outer cylinder 101 and ejects the liquid containing microbubbles 120, a plunger 103 that is inserted into the outer cylinder 101 from the proximal end side and pushes out the liquid containing microbubbles 120, and a gasket 104 fixed to the distal end of the plunger 103.

[0048] Macrobubbles are tiny bubbles with diameters of 10 μm to several tens of μm. The gas that forms the microbubbles 120 is air, carbon dioxide, or the like. Because the macrobubbles are gases, they have ultrasound contrast properties. When the gas is carbon dioxide, the macrobubbles also have X-ray contrast properties. The liquid into which the macrobubbles are mixed is, for example, physiological saline, or a cell protection liquid such as dimethyl sulfoxide (DMSO) or glycerol.

[0049] The biasing device 110 has a connecting part 51 that can be connected to the hub 43, a housing 111 arranged on the base end side of the connecting part 51, a moving part 112 that can move axially relative to the housing 111, a stopper 55 that releasably fastens the moving part 112 to the housing 111 at a predetermined axial position, a release part 56 that releases the stopper 55, and a biasing part 57 that biases the moving part 112 toward the tip side relative to the housing 111.

[0050] Housing 111 is connected to the base end of connecting portion 51. Housing 111 has a connection hole 113 into which cylindrical tip 102 of syringe 100 can be inserted and which can communicate with lumen 45 of puncture device 40, an outer cylinder holding portion 114 which holds outer cylinder 101 of syringe 100, and rails 115 which hold moving portion 112 so that it can move in the axial direction.

[0051] The moving part 112 is housed in a rail 115 of the housing 111 and is movable in the axial direction along the rail 115. The moving part 112 has a pressing part 116 that can press the plunger 103 of the syringe 100.

[0052] Next, a usage example of the medical system 10 according to the second embodiment will be described.

[0053] As in the first embodiment, the surgeon percutaneously inserts the imaging device 90 and the backup catheter 20 into a blood vessel, inserts the guiding catheter 30 into the lumen of the backup catheter 20, and causes the tip of the guiding catheter 30 to protrude from the tip of the backup catheter 20 and reach a predetermined position. At this time, the surgeon positions the tip of the guiding catheter 30 at a puncture position P in the cardiac cavity 306 or blood vessel where the puncture instrument 40 can approach the pericardial cavity 305. Next, at the puncture position P, the surgeon presses the inner wall of the heart or blood vessel toward the pericardial cavity 305 with the tip of the guiding catheter 30 to tent the wall.

[0054] Next, the surgeon inserts the puncture device 40, which is an assembly of the puncture device 40, the biasing device 110, and the syringe 100, into the lumen of the guiding catheter 30. With the puncture device 40, the biasing device 110, and the syringe 100 assembled together, the female thread 58 of the connecting portion 51 of the biasing device 110 is threaded onto the protrusion 44 of the hub 43 of the puncture device 40, connecting the biasing device 110 to the puncture device 40. Furthermore, the moving portion 112 of the biasing device 110 moves toward the proximal end relative to the housing 111, and the hook 66 of the stopper 55 is caught on the engaging portion 65 of the housing 111. Inside the housing 111, the biasing portion 57 is contracted in the axial direction on the proximal side of the moving portion 112. The pressing portion 116 of the moving portion 112 is located on the proximal side of the plunger 103 of the syringe 100.

[0055] Instead of inserting the puncture device 40 into the lumen of the guiding catheter 30 in a state in which the puncture device 40, the biasing device 110, and the syringe 100 are combined, the surgeon may insert the puncture device 40 alone into the lumen of the guiding catheter 30, and then insert the wire 70, which is combined with the biasing device 110 and the wire 70, into the lumen 45 of the puncture device 40.

[0056] Next, while capturing an image of the tented inner wall of the blood vessel or heart using the imaging device 90, the surgeon operates the release unit 56 to release the stopper 55, as shown in FIG. 9B . This disengages the hook 66 from the engagement unit 65, and the moving unit 112 is biased toward the distal end by the biasing unit 57. As a result, the plunger 103 of the syringe 100, which is pressed by the pressing unit 116 of the moving unit 112, gradually moves toward the distal end. As a result, the liquid containing the microbubbles 120 is gradually ejected from the nozzle 102 of the syringe 100 and pushed out from the distal end of the puncture needle 42 of the puncture device 40. The liquid containing the microbubbles 120 is ejected at a substantially constant flow rate into the blood vessel or cardiac chamber 306.

[0057] With the guiding catheter 30 tenting the cardiac inner wall and the liquid containing microbubbles 120 being biased by the biasing instrument 110, the surgeon operates the puncture instrument 40 to move it toward its distal end while capturing an image with the imaging device 90, thereby puncturing the cardiac wall with the puncture needle 42. As soon as the puncture needle 42 reaches the pericardial cavity 305 together with the distal opening 46, the liquid containing microbubbles 120 that was biased by the biasing instrument 110 and discharged into the blood vessel or cardiac cavity 306 is discharged into the pericardial cavity 305, as shown in FIG. 10 . The surgeon can easily confirm in real time the discharge of the liquid containing microbubbles 120 into the pericardial cavity 305 based on the image captured by the imaging device 90, and can stop the movement of the puncture instrument 40 toward the distal end. That is, the surgeon can immediately recognize that the distal opening 46 of the puncture instrument 40 has reached the pericardial cavity 305 and can stop the advancement of the puncture needle 42 (puncture operation). This prevents the puncture needle 42 from being advanced too far, penetrating the outer pericardium 303, or the tip opening 46 from becoming buried in the adjacent myocardium (right auricle 305), allowing for a safe and easy approach to the pericardial cavity 305.

[0058] Next, the surgeon removes the biasing instrument 110 and the syringe 100, leaving the puncture instrument 40 in the pericardial cavity 305. This makes it possible to use the lumen 45 of the puncture instrument 40 to administer medicine into the pericardial cavity 305, insert a treatment instrument, or drain bodily fluids.

[0059] As described above, in the medical system 10 according to the second embodiment, the visualization means may be a liquid containing a plurality of microbubbles 120. This allows the medical system 10 to use the imaging device 90 to observe the microbubbles 120 that pass through the lumen 45 and reach the pericardial cavity 305.

[0060] The present invention is not limited to the above-described embodiment, and various modifications may be made by those skilled in the art within the technical spirit of the present invention. For example, the backup catheter 20 does not have to be included in the medical system 10.

[0061] Furthermore, the distal end opening 46 of the puncture device 40 may be formed at a position different from the inclined distal end surface of the distal end of the puncture device 40. For example, as shown in Fig. 11(A) , the distal end opening 46 may be formed as a side hole penetrating from the outer wall surface to the inner wall surface slightly proximal to the most distal end of the puncture device 40. In this case, the distal end of the biased wire 70 is guided by the distal inner wall surface of the puncture needle 42 and protrudes laterally from the distal end opening 46, and is restricted from further protrusion by abutting against the inner circumferential surface of the guiding catheter 30. Note that it is preferable that the wire 70 not be biased by the biasing device 50 before the tenting state is reached so as not to apply a load to the wire 70.

[0062] When the tip opening 46 of the puncture device 40 is positioned distal to the tip of the guiding catheter 30, the wire 70 biased by the biasing device 50 completely protrudes from the tip opening 46, which is a side hole, and reaches the pericardial cavity 305, as shown in FIG. 11(B).

[0063] This application is based on Japanese Patent Application No. 2023-169567, filed on September 29, 2023, the disclosures of which are incorporated herein by reference in their entirety.

[0064] 10 Medical system 30 Guiding catheter (catheter) 40 Puncture device 41 Shaft 42 Puncture needle 43 Hub 45 Lumen 46 Tip opening 50, 110 Forcing device 53, 112 Moving part 54 Wire fixing part 55 Stopper 56 Releasing part 57 Forcing part 70 Wire (visualization means) 90 Imaging device 100 Syringe 120 Microbubbles (visualization means) 300 Inferior vena cava 301 Right atrium 302 Superior vena cava 303 Pericardium 304 Myocardium 305 Pericardial cavity 306 Heart chamber 307 Right atrial appendage P Puncture position

Claims

1. A medical system comprising: a long, flexible catheter; a long puncture device that can be inserted into the catheter and has a puncture needle at its tip, a lumen extending from its base end to the tip, and a tip opening at the tip that communicates with the lumen; a biasing device that has a movable part that can apply a biasing force toward the tip on material passing through the lumen and a biasing part that biases the movable part; and a releasable stopper that can fix the movable part in a predetermined position.

2. The medical system according to claim 1, further comprising a visualization means for providing ultrasound contrast or X-ray contrast for the material passing through said lumen.

3. The medical system according to claim 2, wherein said visualization means is a wire.

4. The medical system according to claim 2, wherein the visualization means is a liquid containing a plurality of microbubbles.

5. A medical system according to any one of claims 1 to 4, characterized in that the biasing device is detachable from the puncture device.

6. The medical system according to claim 3, wherein the biasing means has a wire fixing portion capable of fixing the wire to the moving portion.

7. A method for approaching the pericardial cavity from within a cardiac cavity or a blood vessel, comprising: preparing a long, flexible catheter; and a long puncture device that can be inserted into the catheter and has a puncture needle at its tip, the long puncture device having a lumen extending from its base end to its tip and a tip opening communicating with the lumen at the tip; inserting the catheter into the blood vessel and carrying the catheter to a puncture position within the cardiac cavity or blood vessel where the puncture device inserted into the catheter can puncture toward the pericardial cavity; at the puncture position, pressing the inner wall of the heart or blood vessel toward the pericardial cavity with the tip located at the tip of the catheter to create a tenting state; imaging the pressed inner wall of the heart or blood vessel with an imaging device, and urging a visualization means having ultrasound contrast or X-ray contrast inserted into the lumen in a direction to push it out of the lumen from the tip opening of the puncture device while restricting the movement of the visualization means from the tip opening to the outside, thereby creating a puncture preparation state; An approach method characterized in that, in the tenting state and in the puncture preparation state, the puncture needle is used to puncture the heart wall or the blood vessel wall through the inner cavity of the catheter to release the restriction on the movement of the visualization means, and the actuated visualization means is inserted into the pericardial cavity through the tip opening of the puncture instrument while being imaged by the imaging device.

Images