JP2015126818A - Embolus capturing device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a less-invasive embolus capturing device that minimizes effect of embolus on the brain especially in TAVI and realizes a smooth operation.SOLUTION: A filter device 1 comprises: a long shaft 2 that has a flexible intermediate coil wire 6 between proximal and distal filter wires 5 and 7; a proximal filter 3 located on the proximal filter wire; and a distal filter 4 located on the distal filter wire. The intermediate coil wire is arranged so as to pass through an indwelling path that extends from a downstream vessel to another downstream vessel over an upstream vessel. Both filters individually have: a contracted state for delivery into the vessel; and an expanded state for capture of an embolus in the vessel. The proximal filter is oriented so that a proximal filter body in the expanded state turns an inlet opening for taking in the embolus to a distal side, and the distal filter is oriented so that a distal filter body in the expanded state turns an inlet opening for taking in the embolus to a proximal side.

Description

  The present invention generally relates to an apparatus for capturing an embolus in a blood vessel of a living body, and more particularly to an embolus capturing apparatus suitable for use in catheter treatment of a human body.

Recently, transcatheter is one of the effective treatment methods for aortic stenosis.
aortic valve implantation (TAVI) is advantageous in that it does not require thoracotomy and places less burden on the patient. TAVI uses a catheter, such as a transfemoral artery approach, to place an artificial valve in the aortic valve of the heart. Further, in stent graft insertion of a thoracic aortic aneurysm (TAA), a catheter is similarly inserted from the femoral artery and a stent graft is placed inside the aneurysm. Embolization such as thrombus that occurs during these catheter treatments can cause serious brain diseases such as cerebral infarction when entering the right common carotid artery directly from the aorta to the left common carotid artery and / or via the brachiocephalic artery .

  In order to reduce the risk of such brain disease and / or prevent its onset, filters for capturing emboli are placed in the left common carotid artery and brachiocephalic artery or right common carotid artery when performing TAVI A method is known (see, for example, Patent Document 1). According to U.S. Patent No. 6,057,028, in one embodiment, two filter devices, each having a separate filter element, are delivered to the left common carotid artery and the right common carotid artery through a common catheter or separate catheters. In another embodiment, the proximal and distal filter elements are attached to a common guide structure, the openings of each filter element are oriented in the inflow direction, and the distal filter element is routed through the right subclavian artery. Deliver to the left common carotid artery and place the proximal filter element in the brachiocephalic artery. In yet another embodiment, a single filter structure is placed along the aortic arch, with a portion of its distal end located in the left common carotid artery and a portion of its proximal end in the brachiocephalic artery or right common carotid artery. Deploy to be placed.

Special table 2011-525405 gazette

  However, the prior art described in Patent Document 1 has the following problems. First, when two filter devices are delivered using a common catheter, the catheter to be used must have a large tube diameter, and the burden on the patient is lightest and there is little risk of complications. Is difficult to insert. Therefore, it is usually inserted from the brachial artery, but puncture of the brachial artery is possible in a relatively short time after surgery, but there is a nerve near the brachial artery and it is more complicated than the femoral artery. There are problems such as a slightly higher incidence of symptoms.

  Next, a filter device having a proximal filter element and a distal filter element attached to a common guide structure, the guide structure having a core wire therein for driving the filter element between a delivery configuration and a deployed configuration. Comprising a single continuous overtube with a proximal filter element and a distal filter element foldably attached to the outer surface of the overtube.

  Since the brachiocephalic artery and the left common carotid artery branch from the aortic arch at a substantially right angle, the overtube must be largely curved from the brachiocephalic artery to the left common carotid artery. However, since the overtube is inserted into the delivery catheter, a certain degree of hardness is required along the axial direction in order to manipulate the core wire to drive the filter element, and as a result, the overtube is relatively bent. Low.

  Therefore, it is difficult to smoothly and quickly insert the overtube from the brachiocephalic artery into the left common carotid artery along the aortic arch, and the operation requires skill. Furthermore, an overtube that is greatly curved in the aortic arch may be in contact with the blood vessel wall and be damaged, or may cause many thrombi. In addition, when a greatly curved overtube is present in the aortic arch, there is a possibility that it may become an obstacle when performing catheter treatment through the aortic arch.

  Further, in a configuration in which a single filter structure is disposed along the aortic arch from the brachiocephalic artery to the right common carotid artery, the filter structure occupies a large space in the aortic arch. Therefore, it may be difficult to deliver the catheter through the aortic arch in a treatment such as TAVI, or the smooth delivery of the artificial valve may be hindered.

  Therefore, the present invention has been made to solve the above-described conventional problems, and its purpose is particularly suitable for use in catheter treatment such as TAVI, in which case embolization of the brain is performed. It is an object of the present invention to provide a minimally invasive embolus capturing device that reduces the burden on the patient while minimizing the influence.

  A further object of the present invention is to provide an embolus capturing device that does not impede the smooth operation of the catheter treatment.

In order to solve such a problem, the present invention is an embolus capture device for capturing an embolus in a vessel,
An elongated shaft member having a proximal filter wire portion, a distal filter wire portion, and an intermediate coil wire portion having flexibility between the proximal filter wire portion and the distal filter wire portion;
A proximal filter portion disposed on the proximal filter wire portion and having a contracted configuration for delivery to a location within the vessel and an expanded configuration for capturing an embolus within the vessel;
A distal filter portion disposed on the distal filter wire portion and having a contracted configuration for delivery to a location within the vessel and an expanded configuration for capturing an embolus within the vessel;
The proximal filter portion has a proximal filter body that opens towards the distal side an inlet opening for capturing an embolus within the vessel in the expanded configuration, and the distal filter portion is embolized within the vessel in the expanded configuration It has a distal filter body which opens the inlet opening for taking in toward the proximal side, It is characterized by the above-mentioned.

  Thus, when the proximal and distal filter portions provided on the single shaft member are respectively disposed in the two downstream vessels branched from the upstream vessel, the one downstream vessel from the downstream vessel Even if the vessels are connected at a tight angle by disposing a flexible intermediate coil wire part in the path that spans the upstream vessel and reaches the other downstream vessel, However, it can be placed in such a way that it strongly contacts with the inner wall of the vessel and is not pressed or damaged, and thus does not cause embolization, and an excellent minimally invasive property can be obtained.

  Therefore, when the embolus capture device of the present invention is used for catheter treatment such as TAVI, TAA, etc., the proximal and distal filter portions are placed in the brachiocephalic artery and the left common carotid artery, thereby embolizing the brain. The treatment can be performed with minimal effects. In addition, a single embolus capturing device having a shaft member having two filter portions can be inserted from a relatively thin vessel such as the radial artery, so that the burden on the patient can be further reduced.

  Further, the intermediate coil wire portion is not greatly bent or occupies a large space in the upstream side vessel. Therefore, when performing catheter treatment such as TAVI, TAA, etc. through the upstream vessel, it is advantageous because the possibility that the smooth operation is hindered by the presence of the intermediate coil wire portion is eliminated or reduced.

In one embodiment, the proximal filter body has a mesh structure made of a wire having elasticity or shape memory, and the wire is bound at the proximal end of the proximal filter body to the proximal filter wire portion. Fixed and movably bound at the distal end of the proximal filter body so as to be in a contracted configuration when moved distally along the proximal filter wire portion and in an expanded configuration when moved proximally;
The distal filter body has a mesh structure made of a wire having elasticity or shape memory, and the wire is bound to the proximal end of the distal filter body and fixed to the distal filter wire portion, and the distal filter body The distal end of the filter body is movably bound so as to be in a contracted configuration when moved distally along the distal filter wire portion and in an expanded configuration when moved proximally.

  The proximal and distal filters are embolized even when they are trapped within the proximal and distal filter bodies by allowing the binding portion of the distal ends of the proximal and distal filter bodies to move. When the capture device is received from the indwelling position in the vessel into the delivery catheter, it can be easily and smoothly changed to the contracted configuration.

  In another embodiment, the shaft member further comprises a flexible tip guide on the distal side of the distal filter wire portion. Thereby, the embolus capture device can be smoothly advanced while being guided by the distal end guide portion in the delivery catheter.

FIG. 1 is an overall schematic view showing a preferred embodiment of a filter device according to the present invention. FIG. 2 is a cross-sectional view showing a state in which the filter device of FIG. 1 is inserted into a delivery catheter. FIG. 3 is a schematic diagram illustrating a process of placing the filter device of FIG. FIG. 4 is a schematic diagram illustrating a process of placing the filter device of FIG. FIG. 5 is a schematic diagram illustrating a process of placing the filter device of FIG. FIG. 6 is a schematic diagram illustrating a process of placing the filter device of FIG. FIG. 7 is an overall schematic view showing a modification of the filter device of FIG. FIG. 8 is a cross-sectional view showing a variation of FIG. 7 inserted into a delivery catheter.

  Hereinafter, a preferred embodiment of an embolus capturing device according to the present invention will be described in detail with reference to the accompanying drawings when applied to a filter device used for TAVI.

  As shown in FIG. 1, the filter device 1 according to this embodiment includes a long shaft 2, and a proximal filter 3 and a distal filter 4 disposed on the tip side of the shaft. The shaft 2 is composed of a thin and flexible wire as a whole in order to advance the inside of the vessel to a desired position through an appropriate guide means such as a delivery catheter and to operate at the proximal end 2a thereof. For the material of the shaft 2, for example, a metal material such as nickel titanium alloy or stainless steel well known as Nitinol (trade name) is suitable.

  On the distal end side of the shaft 2 where the filter is provided, a narrower proximal filter wire portion 5, an intermediate coil wire portion 6, and the proximal filter wire that are reduced in diameter from the proximal end side through a tapered portion 2 b. The distal filter wire portion 7 having the same diameter as that of the portion is continuously provided. A distal end coil wire portion 8 for guiding is further provided at the distal end of the distal filter wire portion 7.

  The intermediate coil wire portion 6 and the tip coil wire portion 8 have a conventionally known structure, and cover a wire portion having a smaller diameter than the proximal and distal filter wire portions 5 and 7 as a core material. A thin coil wire is wound or knitted, and exhibits higher flexibility than the two filter wire portions. If the tip coil wire portion 8 is made of a radiopaque material such as platinum or tungsten, for example, it is advantageous because the position and posture can be confirmed under fluoroscopy at the time of treatment.

  In FIG. 1, the proximal filter 3 and the distal filter 4 are each shown in a radially expanded configuration of the shaft 2 to capture emboli. In this expanded configuration, the proximal and distal filters are respectively proximal and distal filter bodies 9, 10 that are open in a parachute shape, and proximal and distal from the outer peripheries of the proximal and distal filter bodies, respectively. A plurality of string-like support portions 11 and 12 extending to the position filter wire portions 5 and 7 are provided.

  The proximal filter 3 is oriented so that the inlet opening 9a of the proximal filter body 9 faces the distal side, that is, the distal filter 4 side. The distal filter 4 is oriented so that the inlet opening 10a of the distal filter body 10 faces the proximal side, that is, the proximal filter 3 side.

  The proximal and distal filter bodies 9 and 10 of this embodiment are formed by knitting or weaving a plurality of wires that are thin, flexible, elastic or shape memory into a mesh shape. The support portions 11 and 12 are formed by pulling a plurality of the knitted or woven wires from the outer peripheral edges of the proximal and distal filter bodies and bundling them in a string shape.

  The wires constituting the proximal and distal filter bodies 9 and 10 are appropriately selected from conventionally known materials. For example, a nickel-titanium alloy wire, titanium wire, platinum or a composite material of gold wire and nickel-titanium alloy wire, nickel-plated nickel wire, or titanium-based alloy wire is suitable.

  By forming in this way, the proximal and distal filter bodies can capture emboli such as thrombus flowing in the blood flow while passing the blood flow in the blood vessel. Further, the proximal and distal filter bodies can be easily contracted or deformed radially from the expanded configuration and returned to the expanded configuration.

  The proximal end of the proximal filter 3 is bound to a ring-shaped binding tool 13 in which the wire forming the proximal filter body 9 is extrapolated to the proximal filter wire portion 5. The end of the proximal filter is bound to a ring-shaped binding tool 14 in which the ends of all the support portions 11 are similarly inserted on the proximal filter wire portion.

  The proximal-side binding tool 13 is fixed to the proximal filter wire portion 5 at the proximal end side, that is, the end portion on the side coupled to the tapered portion 2b. The distal end side binding tool 14 is slidably moved along the axial direction on the proximal filter wire portion.

  Thereby, the proximal filter 3 causes the proximal filter body 9 to contract radially from the parachute shape and the proximal filter wire portion 5 by moving the binding tool 14 toward the distal end side from the expanded configuration shown in FIG. It changes into the contraction form elongated along. Conversely, when the tying member 14 moves to the proximal end side from the contracted state, the proximal filter 3 returns to the expanded configuration in which the proximal filter body 9 is opened in the parachute shape of FIG.

  Similarly, the base end side end portion of the distal filter 4 is bound to a ring-shaped binding tool 15 in which the end portion of the entire support portion 12 is extrapolated to the distal filter wire portion 7. The distal end of the distal filter is bound to a ring-shaped binding tool 16 in which the wire forming the distal filter body 10 is extrapolated to the distal filter wire portion.

  The proximal end side binding tool 15 is fixed to the distal filter wire portion 7 at its proximal end side, that is, the end portion on the side connected to the intermediate coil wire portion 6. The distal end side binding tool 16 is slidably moved along the axial direction on the distal filter wire portion.

  As a result, the distal filter 4 causes the distal filter body 10 to radially contract from the parachute shape and the distal filter wire portion 7 by the movement of the tying member 16 from the expanded configuration shown in FIG. It changes into the contraction form elongated along. Conversely, when the tying member 16 moves proximally from the contracted state, the distal filter 4 returns to the expanded configuration in which the distal filter body 10 is opened in the parachute shape of FIG.

  For the binders 13 to 16, it is preferable to use a radiopaque metal material such as platinum or tungsten. Thereby, the position of each said binding tool can be confirmed under X-ray fluoroscopy during a surgery.

  FIG. 2 shows a state in which the filter device 1 of FIG. 1 is inserted into a delivery catheter 17 having an inner diameter sufficiently smaller than the maximum outer diameter in the expanded configuration. At this time, the proximal and distal filters 3, 4 are radially contracted by the proximal and distal filter bodies 9, 10 being pressed against the inner wall 17 a of the delivery catheter 17, and at the same time the movable distal side Each binding tool 14 and 16 is slid to the tip side on the filter wire portions 5 and 7, respectively, and has an elongated contraction form along the filter wire portion.

  In use, the filter device 1 is inserted from its proximal end into the delivery catheter 17 that was previously delivered into the patient's vasculature from its distal end and advanced to a predetermined position along the delivery catheter. Alternatively, the delivery catheter 17 is delivered to a predetermined position in the patient's vasculature in a state where the filter device 1 is inserted and stored in advance from the distal end. In either case, when the proximal and distal filters 3, 4 are released from the delivery catheter into the vessel, the elastic or shape memory of the wire that the proximal and distal filter bodies 9, 10 constitute them. Depending on the nature, the movable binding tools 14 and 16 are automatically expanded in the radial direction while sliding toward the base end side.

  Below, the case where the filter apparatus 1 of FIG. 1 is used for TAVI is demonstrated concretely using FIGS. In this embodiment, an approach method in which the filter device 1 is inserted through a radial artery from an incision formed in a patient's wrist is applied.

  First, in FIG. 3, the guide wire 18 is inserted into the radial artery from the incision, and the tip thereof is advanced through the brachiocephalic artery 19 and the aortic arch 20 into the left common clavicular artery 21. Next, as shown in the figure, the delivery catheter 22 made of a microcatheter is extrapolated from the proximal end to the guide wire 18 and delivered so that the distal end opening 22a is located in the left total clavicular artery 21. After this, the guide wire 18 is removed from the delivery catheter 22.

  Thus, the filter device 1 is inserted into the delivery catheter 22 placed in the blood vessel from its distal end through its proximal end opening. The filter device 1 is advanced to the vicinity of the tip of the delivery catheter 22 while the proximal and distal filters 3 and 4 are in the contracted form as shown in FIG. At this time, the filter device 1 can be smoothly guided through the delivery catheter 22 by being guided by the distal coil wire portion 8.

  As shown in FIG. 4, the filter device 1 includes a distal filter 4 located in the left common clavicular artery 21, a proximal filter 3 located in the brachiocephalic artery 19, and an intermediate coil wire portion 6 located in the aortic arch. 20 is extended to a position extending between the brachiocephalic artery 19 and the left common clavicular artery 21. Next, as shown in FIG. 5, only the delivery catheter 22 is pulled proximally so that the distal filter 4 is extracted from the distal opening 22 a to the left common clavicular artery 21. The distal filter released from the delivery catheter 22 automatically changes from the contracted configuration to the expanded configuration of FIG.

  Further, only the delivery catheter 22 is retracted proximally so that the intermediate coil wire portion 6 is extracted into the aortic arch 20 and the proximal filter 3 is extracted into the brachiocephalic artery 19. The distal filter released from the delivery catheter 22 automatically changes from the contracted configuration to the expanded configuration of FIG.

  Thus, as shown in FIG. 6, the filter device 1 includes the distal filter 4 disposed in the left common clavicular artery 21, the proximal filter 3 disposed in the brachiocephalic artery 19, and the intermediate coil wire portion. 6 extends across the aortic arch 20 and extends between the brachiocephalic artery 19 and the left common clavicular artery 21. The arrangement of the filter device 1 can be adjusted by operating the base end 2 a of the shaft 2.

  The distal filter 4 is placed with the distal filter body 10 facing the entrance opening 10a toward the aortic arch 20 so that the parachute shape matches the inner wall of the left common clavicular artery 21. At the same time, the proximal filter 3 is placed with the proximal filter body 9 facing the entrance opening 9a toward the aortic arch 20 and adapting the parachute shape to the inner wall of the brachiocephalic artery 19. As a result, an embolus 23 such as a thrombus in the bloodstream flowing from the upstream aortic arch 20 into the brachiocephalic artery 19 and the left common clavicular artery 21 can be reliably captured while ensuring blood flow.

  Since the intermediate coil wire portion 6 has sufficient flexibility, the joint portion between the aortic arch 20 and the brachiocephalic artery 19 and the left common clavicular artery 21 is tightly close to a substantially right angle along the shape of the joint portion. Passes curved at an angle. Since the intermediate coil wire portion 6 does not come into strong contact with the inner walls of the aortic arch 20, brachiocephalic artery 19 and left common clavicular artery 21, there is a risk that the inner wall of the blood vessel may be damaged or a thrombus may occur compared to the conventional case. It becomes low. Furthermore, after this, the possibility that the presence of the intermediate coil wire portion 6 in the aortic arch 20 hinders the smooth operation of TAVI is greatly reduced.

  After the TAVI operation, the delivery catheter 22 is again advanced along the filter device 1, and the proximal filter 3 and the distal filter 4 are sequentially collected therein. At this time, the proximal and distal filter bodies 9 and 10 are pressed by the tip opening 22a of the delivery catheter, and are housed in the contracted form of FIG. 2 while retaining the emboli captured therein. As described above, since the distal side tying members 14 and 16 are slidable, the proximal and distal filters 3 and 4 can be easily used even when the emboli is captured in the proximal and distal filter bodies. It changes into a contracted form.

  The filter device 1 can be withdrawn from the patient's blood vessel as it is housed in the delivery catheter 22. Alternatively, the filter device 1 can be withdrawn from the delivery catheter first, and then the delivery catheter can be withdrawn from the patient's blood vessel.

  In a variation of this embodiment, stopper members 24, 25 can be provided on the proximal and distal filter wires 5, 7 as shown in FIGS. The stopper members 24 and 25 are fixed between the ties 31 and 14 of the proximal filter 3 and between the ties 15 and 16 of the distal filter 4, respectively, and the proximal ends of the distal slidable ties 14 and 16. Limit the range of movement to the side. Thereby, it can suppress so that the proximal and distal filter main bodies 9 and 10 may not expand beyond a certain level.

  If the filter main body is opened too much, it may easily move from a desired position within the blood vessel, or a new embolization such as a thrombus may occur due to contact with the blood vessel inner wall during movement. In this modification, by providing the stopper members 24 and 25, the expansion of the proximal and distal filter bodies 9 and 10 can be suppressed, thereby preventing undesirable movement and embolization in the blood vessel. .

  In this embodiment, the case where the filter device 1 of the present invention is used for TAVI has been described. However, the present invention can also be applied to TAA that performs treatment in the aorta. In addition, the present invention can be used for blood vessels other than the brachiocephalic artery and the left common clavicular artery branched from the aorta, or all vessels such as lymphatic vessels.

  The present invention is not limited to the above-described embodiments, and various modifications and changes can be made to the above-described embodiments within the technical scope thereof. For example, the shaft constituting the filter device and / or the surface of each filter can be coated with an appropriate agent. In particular, when a hydrophilic coating is applied, since it exhibits lubricity by touching blood, an operation for introducing it into the blood vessel is facilitated.

DESCRIPTION OF SYMBOLS 1 Filter apparatus 2 Shaft 3 Proximal filter 4 Distal filter 5 Proximal filter wire part 6 Intermediate coil wire part 7 Distant filter wire part 8 Tip coil wire part 9 Proximal filter main body 10 Distal filter main body 11, 12 Support part 13 to 16 Bundling tools 17 and 22 Delivery catheter 18 Guide wire 19 Brachiocephalic artery 20 Aortic arch 21 Left common clavicular artery 23 Embolization

Claims (3)

An embolus capture device for capturing an embolus within a vessel,
A long shaft member having a proximal filter wire portion, a distal filter wire portion, and an intermediate coil wire portion having flexibility between the proximal filter wire portion and the distal filter wire portion;
A proximal filter portion disposed on the proximal filter wire portion and having a contracted configuration for delivery to a location within the vessel and an expanded configuration for capturing an embolus within the vessel;
A distal filter portion disposed on the distal filter wire portion and having a contracted configuration for delivery to a location within the vessel and an expanded configuration for capturing an embolus within the vessel;
The proximal filter portion has a proximal filter body that opens toward the distal side an inlet opening for capturing an embolus within a vessel in the expanded configuration, wherein the distal filter portion is in the expanded configuration. An embolus capture device having a distal filter body that opens toward the proximal side an inlet opening for capturing an embolus in a vessel. The proximal filter body has a mesh structure made of a wire having elasticity or shape memory, and the wire is bound at the proximal end of the proximal filter body and fixed to the proximal filter wire portion; And, at the distal end of the proximal filter body, the contracted form is formed when the distal end is moved along the proximal filter wire portion, and is movably bound so as to be the expanded form when the proximal end is moved. ,
The distal filter body has a mesh structure made of a wire having elasticity or shape memory, and the wire is bound to a proximal end of the distal filter body and fixed to the distal filter wire portion; And, at the distal end of the distal filter body, it is movably bound so as to be in the contracted form when moved distally along the distal filter wire part and to be in the expanded form when moved proximally. The embolus capture device according to claim 1.   The embolus capture device according to claim 1 or 2, wherein the shaft member further includes a flexible tip guide portion on a distal side of the distal filter wire portion.

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