JP7607424B2 - Clot removal device - Google Patents

Description

The present invention relates to a thrombus removal device.

A thrombus removal device is a medical instrument that is inserted into a blood vessel to perform a treatment to remove a thrombus from the body. Patent Document 1 describes a percutaneous thrombus removal device. This percutaneous thrombus removal device includes an insertion tool and a removal tool. The insertion tool includes an outer sheath, and an outer sheath base body on the proximal end side of the outer sheath. The removal tool includes an inner sheath, and an inner sheath base body on the rear end side of the inner sheath. The inner sheath is inserted inside the outer sheath. A deployable removal member is provided at the tip of the inner sheath. In this percutaneous thrombus removal device, the diameter of the tip of the removal member expands more than the inner diameter of the outer sheath, and the diameter of the capture port expands to capture the thrombus in front of the removal member.

JP 2007-319272 A

In the thrombus removal device described in Patent Document 1, there are cases where the thrombus is left unremoved. This is particularly likely to occur when the thrombus is large, and there are also cases where it is difficult to remove the thrombus from the body. For this reason, it is desirable to provide a thrombus removal device that can remove the thrombus from the body without leaving it unremoved.

The present invention was made in consideration of the above-mentioned circumstances, and its purpose is to provide a thrombus removal device that can remove thrombus from the body without missing any.

In order to achieve the above object, the thrombus removal device according to the present invention comprises:
a first catheter having an axially extending device lumen;
an expansion member that is movable through the device lumen, protrudes from a distal opening of the device lumen, and expands outward in a radial direction of the first catheter to become in an expanded state capable of capturing a thrombus;
Equipped with
the first catheter has a stretchable portion having circumferential stretchability at a distal end portion where the distal opening is formed,
When the expansion member in the expanded state is received in the device lumen through the distal opening, the distal opening is expandable by the expansion of the telescopic portion.

The thrombus removal device according to the present invention further comprises:
A second catheter is inserted through the device lumen,
The second catheter
supporting the expansion member at a distal end;
The device may be movable axially within the lumen.

The thrombus removal device according to the present invention further comprises:
The second catheter may have a suction lumen formed along the axial direction, and a suction device may be connected to the proximal end of the second catheter for sucking the thrombus captured by the expansion member proximally by suction within the suction lumen.

The thrombus removal device according to the present invention further comprises:
The apparatus may further include a first destruction device that is insertable through the suction lumen and that applies a physical stimulus to the thrombus to destroy it.

The thrombus removal device according to the present invention further comprises:
The device may further comprise a second disruption device positionable outside the second catheter within the device lumen to apply a physical stimulus to the second catheter to disrupt the thrombus.

The thrombus removal device according to the present invention further comprises:
The catheter may further include a balloon provided at a distal end of the first catheter and expandable by supplying a fluid thereto.

The thrombus removal device according to the present invention further comprises:
The first catheter has a wire lumen through which a guidewire is inserted formed along the axial direction,
The wire lumen portion may be disposed external to the device lumen.

The thrombus removal device according to the present invention further comprises:
A thin-walled portion extending along the axial direction may be formed at the distal end of the first catheter, and the elastic portion may be located at the thin-walled portion.

The thrombus removal device according to the present invention further comprises:
The stretchable portion may occupy a range of 50% to 80% of the circumference at the distal end of the first catheter.

The thrombus removal device according to the present invention further comprises:
A length of the telescopic portion in the axial direction may be longer than a length of the expansion member in the axial direction.

It is possible to provide a thrombus removal device that can remove thrombus from the body without missing any.

FIG. 1 is a diagram illustrating the overall configuration of a thrombus removal device. 2 is a cross-sectional view taken along the line II-II of FIG. 1. 3 is a cross-sectional view taken along the line III-III in FIG. 1 . 4 is a cross-sectional view taken along the line IV-IV in FIG. FIG. 13 is a side view of the first shaft tip when the expansion member is positioned within the device lumen proximal to the telescopic portion. 13 is a side view of the first shaft tip when the expansion member is positioned within the device lumen in the range in which the expansion section extends in the axial direction. FIG. FIG. 13 is a side view of the first shaft tip when the extension portion is exposed distally from within the device lumen. FIG. 2 is a side view of the first catheter with its tip introduced to the vicinity of a thrombus in a blood vessel. FIG. 2 is a side view of the first catheter with the tip of the first catheter anchored near a thrombus in a blood vessel. FIG. 2 is a side view of the first catheter in a state in which a thrombus is captured by the expansion portion. FIG. 13 is an explanatory diagram of the state in which the expansion portion that has captured the thrombus is in the process of being accommodated within the device lumen. FIG. 13 is an explanatory diagram of the state in which the expansion portion that has captured the thrombus is housed within the device lumen. 13 is a cross-sectional view taken along the line XII-XII in FIG. 12. 13 is a cross-sectional view of a first shaft when the thrombus removal device is equipped with a destruction device. FIG. FIG. 11 is a cross-sectional view of a first shaft according to another embodiment.

A thrombus removal device according to an embodiment of the present invention will be described with reference to the drawings. The thrombus removal device according to this embodiment is a medical instrument that is inserted into a blood vessel and performs treatment to remove thrombus by suction.

First Embodiment
(Explanation of overall configuration)
As shown in Fig. 1, a thrombus removal device 100 (hereinafter referred to as device 100) according to this embodiment includes a first catheter 1 which is an elongated member having a device lumen 11 (see Figs. 2 to 4) formed along its axial direction (extension direction), a second catheter 2 which is an elongated member inserted into the device lumen 11, a tubular expansion member 3 supported at the tip of the second catheter 2 and movable through the device lumen 11, a balloon B fixed to the distal end of the first catheter 1, a catheter hub H (hereinafter referred to as hub H) which is connected to the proximal end of the first catheter 1 and serves as an operation interface for the first catheter 1 and the second catheter 2, and a thrombus suction device S connected to the second catheter 2. A part of the distal end of the first catheter 1 which is a part of the wall of the device lumen 11 is an elastic part 5 made of an elastic material. The expansion member 3 protrudes from the distal opening of the device lumen 11 and expands outward in the radial direction of the first catheter 1 (hereinafter simply referred to as the "radial direction"), thereby entering an expanded state capable of capturing a thrombus. The first catheter 1 has an elastic portion 5 having circumferential elasticity at the distal end portion where the distal opening is formed. Therefore, when the expansion member 3 in the expanded state capturing a thrombus is accommodated in the device lumen 11 through the distal opening, the distal opening can be expanded by the extension of the elastic portion 5. This allows the expansion member 3 in the expanded state to be drawn into the device lumen 11 of the first catheter 1 while capturing a thrombus. Therefore, the thrombus captured by the expansion member 3 is less likely to jump out into the blood vessel, and the occurrence of missed thrombus can be suppressed.

In the following, the same direction as the axial direction of the first catheter 1 may be simply referred to as the axial direction. Note that the proximal side refers to the side that is located outside the body in the axial direction of the first catheter 1 when the device 100 is in use. The distal side refers to the side opposite the proximal side in the axial direction of the first catheter 1. The distal side refers to the side that is inserted into the body when the device 100 is in use.

The second catheter 2 has an aspiration lumen 21 (see Figures 2 to 4) formed along its axial direction (the same direction as the axial direction of the first catheter 1). The aspiration lumen 21 is connected to a suction device S (see Figure 1). The second catheter 2 supports the expansion member 3 at its distal end. The second catheter 2 is movable in the axial direction within the device lumen 11.

The expansion member 3 can move axially in the device lumen 11 by the axial movement of the second catheter 2. The expansion member 3 can move axially relative to the first catheter 1 in a state where a part of the expansion member 3 protrudes distally from the distal opening of the device lumen 11 and is exposed, and a state where the entire expansion member 3 is housed in the device lumen 11. In other words, the expansion member 3 can freely move forward and backward between the proximal and distal sides across the inside and outside of the device lumen 11. The expansion member 3 of this embodiment can be expanded radially outward. More specifically, the expansion member 3 of this embodiment is a mesh tube portion formed of struts and forming a cylindrical outer periphery. The mesh tube portion as the expansion member 3 can move within the device lumen 11 in the axial direction of the first catheter 1 with its axial direction aligned with the axial direction of the first catheter 1. The mesh tube portion as the expansion member 3 can be expanded radially outward by a part of the mesh tube portion protruding distally from the distal opening of the device lumen 11. The protruding portion of the mesh tube portion serving as the expansion member 3 that protrudes from the distal opening of the device lumen 11 expands radially outward, so that its inner diameter becomes larger than the diameter of the device lumen 11. In other words, the inner diameter of the capture port that captures the thrombus, located at the distal end of the mesh tube portion serving as the expansion member 3, becomes larger than the diameter of the distal opening of the device lumen 11. This makes it easier to capture the thrombus through the capture port of the expansion member 3.

The device 100 expands the expansion member 3 by projecting the expansion member 3 from the distal opening of the device lumen 11 of the first catheter 1. The expansion member 3 captures the thrombus, and the expansion member 3 capturing the thrombus is accommodated back into the device lumen 11, thereby removing the thrombus from the blood vessel. The first catheter 1 can lengthen the circumference of the distal end of the device lumen 11 by extending the stretchable section 5, thereby expanding the diameter. As a result, even if the maximum outer diameter of the expansion member 3 capturing the thrombus is larger than the diameter of the distal opening of the device lumen 11, the device 100 can accommodate the expansion member 3 in the device lumen 11 by expanding the diameter of the distal opening of the device lumen 11. The thrombus is sucked proximally by the suction device S (see FIG. 1) through the suction lumen 21, for example, and removed from the body. Details regarding thrombus removal will be described later.

(Explanation of each part)
As shown in Fig. 1, the first catheter 1 is a long member made of a polymeric material such as nylon, silicone resin, or fluororesin. As shown in Figs. 1 and 2, a balloon B is fixed to the distal end of the first catheter 1. As shown in Figs. 1 and 2, a part of the distal end of the first catheter 1 is an elastic part 5 made of an elastic body. In other words, a part of the circumferential area of the distal end of the first catheter 1 is an elastic part 5 made of an elastic body. As shown in Figs. 3 and 4, the first catheter 1 is formed with a device lumen 11, a wire lumen 12, and an inflation lumen 13 as through holes along the axial direction. As shown in Fig. 1, a marker M that enables imaging by X-ray electrophotography can be arranged at the tip of the first catheter 1.

As shown in Figures 3 and 4, the expansion member 3 and the second catheter 2 are inserted into the device lumen 11. The device lumen 11 opens to the outside through a distal opening formed at the distal end, which is the tip of the distal side of the first catheter 1. The device lumen 11 extends from the distal opening engaged with the distal end to the hub H (see Figure 1). The expansion member 3 and the second catheter 2 can be inserted into the device lumen 11 through a port or the like provided in the hub H. The cross section perpendicular to the axial direction of the device lumen 11 is, for example, circular. By forming the cross section perpendicular to the axial direction of the device lumen 11 into a circular shape, the sliding of the second catheter 2 described later becomes smooth. It is preferable to apply a hydrophilic coating to the wall surface of the device lumen 11 (the inner wall surface of the first catheter 1). This makes the sliding of the second catheter 2 described later even smoother. Suitable hydrophilic coating agents include cellulose-based polymeric substances, polyethylene oxide-based polymeric substances, maleic anhydride-based polymeric substances (e.g., maleic anhydride copolymers such as methyl vinyl ether-maleic anhydride copolymers), acrylamide-based polymeric substances (e.g., polyacrylamide, polyglycidyl methacrylate-dimethylacrylamide (PGMA-DMAA) block copolymers), water-soluble nylon, polyvinyl alcohol, polyvinylpyrrolidone, etc.

A guide wire for guiding the first catheter 1 inside a blood vessel or the like is inserted into the wire lumen 12. The wire lumen 12 extends from a distal opening located at the distal end of the first catheter 1 to a proximal end, which is the base end on the proximal side of the first catheter 1. The wire lumen 12 opens to the outside through the space within the hub H. The cross section of the wire lumen 12 perpendicular to the axial direction is, for example, circular.

The inflation lumen 13 is a flow path that supplies fluid to the balloon B. An example of the fluid is physiological saline containing a contrast agent for X-ray electrography. The inflation lumen 13 is connected to the internal space of the balloon B. The inflation lumen 13 extends across the hub H, and can receive a supply of fluid via a port or the like provided in the hub H. The cross section of the inflation lumen 13 perpendicular to the axial direction is, for example, circular.

The stretchable portion 5 is made of a polymer material such as silicone rubber, and is formed of a stretchable elastic body (a so-called elastomer, hereinafter simply referred to as elastomer). As a result, the stretchable portion 5 is capable of elastic deformation accompanied by circumferential extension. The stretchable portion 5 extends from the distal end (hereinafter simply referred to as the "distal end") of the first catheter 1 along the axial direction to the proximal side. As shown in FIG. 2, the stretchable portion 5 forms a part of the wall of the device lumen 11 in the first catheter 1. The distal opening of the device lumen 11 can be expanded by the extension of the stretchable portion 5. That is, the device lumen 11 can be expanded to increase the circumferential length of the distal end portion. This allows the device lumen 11 to be expanded to increase the maximum diameter of the distal end portion. This also allows the device lumen 11 to be expanded to increase its cross-sectional area. In this embodiment, the circumferential length of the device lumen 11 refers to the circumferential length of the hole of the device lumen 11 in a cross section perpendicular to the axial direction of the first catheter 1. In addition, the maximum diameter of the distal end of the device lumen 11 in this embodiment is the maximum linear distance between two points on the wall surface of the device lumen 11 where the linear distance is maximum in a cross section perpendicular to the axial direction of the first catheter 1.

The stretchable portion 5 is formed in the first catheter 1 over a range of 50% or more of the circumference of the device lumen 11. In the present embodiment, as an example, the stretchable portion 5 is formed continuously over a range of 60% of the circumference of the device lumen 11 in the first catheter 1. It is preferable that the stretchable portion 5 is formed in the first catheter 1 over a range of 50% to 80% of the circumference of the device lumen 11. By setting the stretchable portion 5 in this range, the strength of the distal end of the first catheter 1 can be maintained while increasing the expandable circumference, maximum diameter, and cross-sectional area (hereinafter, sometimes referred to as maximum diameter, etc.) at the distal end of the device lumen 11. The extension length of the stretchable portion 5 in the axial direction is longer than the axial length of the expansion member 3. In this way, the entire axial area of the expansion member 3 can be accommodated in the device lumen 11 within the axial area in which the stretchable portion 5 is provided.

The balloon B is a bag having an internal space. The balloon B can be expanded by supplying fluid to the internal space from the inflation lumen 13. The balloon B is fixed to the outer surface of the first catheter 1, for example, on the radially opposite side of the first catheter 1 relative to the stretchable section 5. The balloon B is also disposed, for example, within the range in which the stretchable section 5 extends in the axial direction. The position of the first catheter 1 can be fixed within the blood vessel by expanding the balloon B. The balloon B is a so-called anchor balloon. Hereinafter, the fixing of the position of the first catheter 1 within the blood vessel by expanding the balloon B may be simply referred to as anchoring.

As shown in Figs. 1 and 5 to 7, the second catheter 2 is a long member made of, for example, an elastomer. The second catheter 2 is preferably made of an elastomer that has higher stretchability and lower elasticity than the stretchable section 5. The second catheter 2 is movable in the axial direction within the device lumen 11 while sliding against the wall of the device lumen 11.

As shown in Figures 2 to 4, the second catheter 2 has an aspiration lumen 21 formed as a through hole along the axial direction. The cross section of the aspiration lumen 21 perpendicular to the axial direction is, for example, circular. This makes it easier to aspirate the thrombus 91, which will be described later. The inner wall surface of the second catheter 2, which serves as the wall surface of the aspiration lumen 21, is preferably coated with a drug having medicinal properties as a thrombolytic drug that dissolves thrombi. This dissolves the thrombus 91 within the aspiration lumen 21, making it easier to aspirate the thrombus 91, which will be described later. Examples of such drugs include heparin, EDTA-2K, sodium citrate, sodium fluoride, warfarin, and urokinase.

In this embodiment, as shown in Figures 1 to 3 and 5 to 7, an expansion section 23 in which the expansion member 3 is embedded is formed at the tip of the second catheter 2. That is, in this embodiment, the second catheter 2 supports the expansion member 3 in a state in which the expansion member 3 is embedded in the wall. The expansion section 23 also serves as the wall of the suction lumen 21. That is, the expansion section 23 is cylindrical.

The expansion member 3 is a mesh-like, tubular member formed of wire material 30 (see FIG. 3), such as a metal strut. For example, a titanium-based alloy spring material can be used as the wire material 30. An example of a titanium-based alloy spring material is a nickel-titanium alloy.

By embedding the expansion member 3 within the wall of the second catheter 2 as described above, it is possible to prevent damage to the wall of the device lumen 11 and blood vessels due to contact with the wire 30, particularly the sharp corners of the end face of the wire 30.

In this embodiment, the expansion member 3 is accommodated in the device lumen 11 proximal to the stretching section 5 in a state in which it is contracted by elastic deformation in both the state in which it captures a thrombus and the state in which it does not capture a thrombus. In addition, the expansion member 3 is accommodated in a state in which it is contracted by elastic deformation in the position in the device lumen 11 where the stretching section 5 is provided in the state in which it does not capture a thrombus. In contrast, when the expansion member 3 protrudes from the distal opening of the device lumen 11, it expands in the radial direction by a restoring force. In other words, the cylindrical expansion member 3 of this embodiment is formed so that it can be expanded so that the inner diameter expands by the restoring force due to its own spring elasticity. In this embodiment, the expansion member 3 expands both the inner diameter and the outer diameter. In the following, the inner diameter and the outer diameter of the expansion member 3 may be collectively referred to as the diameter. In the following, the expansion member 3 expanding in diameter by the restoring force due to its own spring elasticity may be simply referred to as self-expansion.

As shown in FIG. 6, when the expansion member 3 is located in the device lumen 11 in the range in which the stretchable portion 5 extends in the axial direction, the expansion member 3 is allowed to self-expand within the range in which the inner diameter of the device lumen 11 expands due to the expansion of the stretchable portion 5. However, the stretchable portion 5 has an elastic modulus that is not expanded by the restoring force of the self-expanding expansion member 3 alone. When the expansion member 3 captures a thrombus and is located in the device lumen 11 in the range in which the stretchable portion 5 extends in the axial direction, the stretchable portion 5 expands during thrombus retrieval, expanding the inner diameter of the device lumen 11.

As shown in Figures 6 and 7, as the expansion member 3 self-expands, the expansion section 23 of the second catheter 2 also expands in diameter. This expands the diameter of the distal opening of the expansion section 23, which is the distal end of the suction lumen 21, making it possible for the second catheter 2 to capture large thrombi. In other words, the expansion member 3 of this embodiment captures thrombi via the expansion section 23.

(How to use)
Next, a method for using the device 100 will be described.

After the guidewire and insertion sheath are inserted into the patient's blood vessel 9, the first catheter 1 is inserted into the blood vessel from the distal side through the insertion sheath. Then, as shown in FIG. 8, the tip of the first catheter 1 is introduced to the vicinity of the thrombus 91, using the position of the marker M as a guide using contrast imaging such as an X-ray electron photograph. As shown in FIG. 9, when the tip of the first catheter 1 reaches the vicinity of the thrombus 91, the balloon B is expanded to anchor the first catheter 1.

Next, the second catheter 2 is inserted into the device lumen 11 of the first catheter 1 (see Figures 1 and 5). The second catheter 2 is then guided through the device lumen 11, and the expansion section 23 in which the expansion member 3 is embedded is introduced to the distal end of the device lumen 11 (see Figure 6). Furthermore, as shown in Figure 10, the expansion section 23 is introduced near the thrombus 91, and the thrombus 91 is captured within the expansion section 23.

As shown in FIG. 10, when the expansion section 23 is exposed to the outside of the device lumen 11, its diameter is expanded by the self-expansion of the expansion member 3. The expansion section 23, which has a diameter expanded compared to when it is contained in the device lumen 11, can capture a thrombus 91 that is larger than the diameter of the device lumen 11. In other words, even a large thrombus 91 can be captured without being missed.

After capturing the thrombus 91 with the expansion section 23, the second catheter 2 is pulled proximally to accommodate the expansion section 23 in the device lumen 11. This removes the thrombus 91 from the blood vessel 9. Here, the expansion section 23 captures the thrombus 91 that is larger than the diameter of the device lumen 11, and there may be cases where the expansion section 23 cannot be easily contracted due to steric hindrance caused by the thrombus 91. Even in this case, the diameter of the device lumen 11 can be expanded by extending the stretch section 5, so that the diameter of the device lumen 11 can be expanded to accommodate the expansion section 23 in the device lumen 11, as shown in Figures 11, 12, and 13. In order to expand the diameter of the device lumen 11 to accommodate the expansion section 23 in the device lumen 11, for example, the second catheter 2 may be pulled somewhat strongly proximally. This allows the expanded expansion section 23 to be expanded so as to push out the stretch section 5 with the expanded expansion section 23, thereby expanding the diameter of the device lumen 11, and at the same time, the expanded expansion section 23 can be accommodated in the device lumen 11.

As described above, the extension length of the expansion section 5 in the axial direction is formed to be longer than the axial length of the expansion member 3. As a result, as shown in FIG. 12, when the distal end of the expansion section 23 is completely accommodated in the device lumen 11 and the distal end of the expansion section 23 is located proximal to the distal opening of the device lumen 11, the diameter near the distal opening of the device lumen 11 shrinks due to the contraction of the expansion section 5 and returns to its original size, becoming smaller than the diameter near the expansion section 23 in the device lumen 11. This prevents the thrombus 91 captured by the expansion section 23 from leaking out of the distal opening of the device lumen 11.

After the expansion section 23 is housed in the device lumen 11, there are several methods available for removing the thrombus 91 from the device 100 to the outside of the body. Below, we will explain one example of a method for removing the thrombus 91 from the device 100 to the outside of the body, and the subsequent procedures until the completion of treatment.

(Example 1 of a method for removing a thrombus)
The thrombus 91 can be removed from the body by sucking it proximally through the suction lumen 21 with the suction device S (see FIG. 1). This is a suitable method when the thrombus 91 can easily pass through the suction lumen 21 by being easily deformed or collapsed by the suction force of the suction device S.

After the thrombus 91 is removed from the body by suction, the balloon B is deflated to release the anchoring. After the balloon B has deflated, the first catheter 1 and the second catheter 2 are pulled out of the body. The guidewire and insertion sheath are then pulled out of the body, and bleeding is stopped, etc., to complete the treatment.

(Example 2 of a method for removing a thrombus)
In cases where the thrombus 91 is not easily deformed or disintegrated by the suction force of the suction device S, it may be advisable to carry out the following method to deform and disintegrate the thrombus 91 prior to suction with the suction device S. That is, the second catheter 2 is pulled strongly. As a result, the expansion section 23 expanded by the thrombus 91 is drawn into the device lumen 11 proximal to the expansion section 5. This drawing causes the expansion section 23 and the expansion member 3 to contract as if they are restricted and crushed by the wall of the device lumen 11. The contraction of the expansion section 23 causes the thrombus 91 to be crushed, deformed, and disintegrated. If this deformation and collapse allows the thrombus 91 to easily pass through the suction lumen 21 by the suction force of the suction device S, the thrombus 91 can be sucked proximally and removed from the body.

When the second catheter 2 is pulled strongly to pull the expansion section 23 expanded by the thrombus 91 into the device lumen 11 proximal to the stretch section 5, the diameter of the distal end of the device lumen 11 shrinks from the distal side due to the contraction of the stretch section 5. That is, the distal end of the device lumen 11 returns to its original diameter over the entire area to which the stretch section 5 extends. Therefore, when the expansion section 23 expanded by the thrombus 91 is pulled into the device lumen 11 proximal to the stretch section 5 to deform and collapse the thrombus 91, leakage of the thrombus 91 from the distal opening of the device lumen 11 is suppressed.

After the thrombus 91 is removed from the body by suction, the procedure is the same as in Example 1 of the thrombus removal method.

(Example 3 of Thrombus Removal Method)
If the thrombus 91 does not deform or collapse to such an extent that it can easily pass through the suction lumen 21 by the suction force of the suction device S even when the expansion section 23 expanded by the thrombus 91 is pulled into the device lumen 11 proximal to the expansion section 5 by strongly pulling the second catheter 2, the following method can be adopted: That is, the second catheter 2 can be pulled out of the body as it is from the device lumen 11, and the thrombus 91 can be taken out of the body.

After the thrombus 91 is removed from the body, the balloon B is deflated to release the anchoring. After the balloon B has deflated, the first catheter 1 is pulled out of the body. The guidewire and insertion sheath are then pulled out of the body, and bleeding is stopped, etc., to complete the treatment.

(Example 4 of Thrombus Removal Method)
If the expansion section 23 expanded by the thrombus 91 cannot be retracted into the device lumen 11 proximal to the expansion section 5 even when the second catheter 2 is pulled strongly, or if the second catheter 2 cannot be pulled out of the body from the device lumen 11 as it is, the balloon B is deflated to release the anchoring. After the balloon B is deflated, the first catheter 1 can be pulled out of the body together with the second catheter 2, and the thrombus 91 can be taken out of the body.

After the first catheter 1 is pulled out of the body, the guidewire and insertion sheath are also pulled out of the body, and bleeding is stopped, etc., and treatment is completed.

[Modification of the first embodiment]
A modification of the first embodiment will now be described.

In the first embodiment, examples 1 to 4 of the thrombus removal method were described as a method for removing the thrombus 91 from the body using the device 100. The device 100 described in the first embodiment can further include a destruction device that destroys the thrombus within the device lumen 11.

As shown in FIG. 14, the device 100 (see FIG. 1) may include a first destruction device 81 formed of, for example, a wire, rod-shaped, or plate-shaped member such as a titanium alloy. The first destruction device 81 is inserted into the suction lumen 21 for use. Specifically, the first destruction device 81 destroys the thrombus 91 by applying physical stimuli to the thrombus 91 in the suction lumen 21, such as piercing, crushing, cutting, or vibrating the thrombus 91. This makes it possible to suck the thrombus 91 with the suction device S even if the thrombus 91 cannot be deformed or destroyed by the above-mentioned thrombus removal method example 1 or thrombus removal method example 2. FIG. 14 illustrates an example of the first destruction device 81, which is a wire, destroying the thrombus 91 by crushing it.

As shown in FIG. 14, the device 100 (see FIG. 1) may also include a second destruction device 82 such as a balloon, a wire, or a scissors-like member. The second destruction device 82 is disposed outside the second catheter 2 in the device lumen. The second destruction device 82 may be any device that applies a physical stimulus such as deforming the second catheter 2 or applying vibration to the second catheter 2. The second destruction device 82 can destroy the thrombus 91 in the suction lumen 21 by applying a physical stimulus such as the deformation of the second catheter 2 or the vibration applied to the second catheter 2 to the thrombus 91 in the suction lumen 21 via the second catheter 2. FIG. 14 illustrates an example in which the second destruction device 82, which is a balloon, presses the second catheter 2 from the outside to cause it to deform, thereby crushing and destroying the thrombus 91 in the suction lumen 21. In addition, when the second destruction device 82 is a balloon, the second catheter 2 can be pressed from the outside by expanding it by supplying a fluid, for example. If the second destruction device 82 is a wire, the second catheter 2 can be pressed by pressing it. If the second destruction device 82 is a scissors-shaped member, it can be used to pinch and press the second catheter 2.

The first and second destructive devices 81 and 82 may be used individually or simultaneously as shown in FIG. 14. FIG. 14 shows the first and second destructive devices 81 and 82 being used simultaneously, and further shows the state in which the thrombus 91 is sandwiched between the first and second destructive devices 81 and 82 to destroy the thrombus 91.

In this way, a thrombus removal device can be provided that can remove thrombus from the body without missing any.

[Another embodiment]
(1) In the above embodiment, the stretchable portion 5 is continuously formed over a range of 60% of the circumferential length of the device lumen 11 in the first catheter 1. It has also been described that the stretchable portion 5 is preferably formed over a range of 50% to 80% of the circumferential length of the device lumen 11 in the first catheter 1. It has also been described that setting the stretchable portion 5 in this range makes it possible to maintain the strength of the distal end portion of the first catheter 1 while increasing the maximum diameter, etc., at which the distal end portion of the device lumen 11 can be expanded. However, it is not essential that the stretchable portion 5 is set in this range.

Even if the stretchable section 5 is formed over a range that exceeds 80% of the circumference of the device lumen 11 in the first catheter 1, it is sufficient to take measures to maintain the strength of the distal end of the first catheter 1. One example of a measure to maintain strength is to provide a reinforcing member such as an axially extending rib at the distal end of the first catheter 1.

As shown in FIG. 15, even if the stretchable portion 5 is formed in the first catheter 1 in a range limited to less than 50% of the circumference of the device lumen 11, the diameter of the distal end of the device lumen 11 can be expanded. When the stretchable portion 5 is formed in the first catheter 1 in a range limited to less than 50% of the circumference of the device lumen 11, it is preferable to position the stretchable portion 5 slightly inward from the outer peripheral surface of the first catheter 1 in the radial direction of the device lumen 11. This positioning is preferable because it makes it easier to expand the diameter of the device lumen 11.

(2) In the above embodiment, the maximum diameter of the distal end of the device lumen 11 can be expanded by the extension of the expandable section 5. In addition, as shown in FIG. 15, a thin-walled section 15 extending along the axial direction may be formed at the distal end of the first catheter 1. The expandable section 5 may be located within the same axial range as the range in which the thin-walled section 15 extends. The thin-walled section 15 can be formed as a thin-walled section, such as a recess or cut along the axial direction, formed on the inner wall of the first catheter 1. The thin-walled section 15 is thinner than other parts of the first catheter 1 and is more easily deformed. Therefore, when the expandable section 5 expands and contracts, the wall of the first catheter 1 easily bends with the thin-walled section 15 as a fulcrum. This makes it easier to expand the maximum diameter of the distal end of the device lumen 11.

The formation of the thin-walled portion 15 is particularly beneficial when the stretchable portion 5 is limited to an area of less than 50% of the circumference of the device lumen 11 in the first catheter 1. Even if the area in which the stretchable portion 5 is formed is not sufficiently large, or the area in which the stretchable portion 5 is formed cannot be sufficiently large, the formation of the thin-walled portion 15 can facilitate the expansion of the maximum diameter of the distal end of the device lumen 11, etc.

The thin-walled portion 15 may be formed on the outer wall of the first catheter 1 on the radially outer side, or on the inner wall of the first catheter 1, which is the wall of the device lumen 11 in the first catheter 1. It is preferable to form the thin-walled portion 15 on the wall of the device lumen 11 in the first catheter 1, because this makes it easier to expand the maximum diameter of the distal end of the device lumen 11.

Figure 15 shows a case where a pair (two) of thin-walled portions 15 are formed in the wall portion of the device lumen 11 in the first catheter 1. However, the number of thin-walled portions 15 is not limited to one or two. There may be one thin-walled portion 15, or three or more thin-walled portions 15 may be formed.

(3) In the above embodiment, the case where the expansion member 3 is embedded and supported within the wall of the second catheter 2 and the expansion section 23 is formed has been described. However, the expansion member 3 is not limited to being embedded and supported within the wall of the second catheter 2. The expansion section 23 may be the expansion member 3 fixed to the outer peripheral surface of the second catheter 2, or the expansion member 3 fixed to the wall surface of the suction lumen 21. In other words, the expansion member 3 may be fixed and supported to the outer peripheral surface of the second catheter 2 or the wall surface of the suction lumen 21.

When the expansion member 3 is not embedded in the wall of the second catheter 2, it is preferable to form the expansion section 23 by fixing the expansion member 3 to the outer peripheral surface of the second catheter 2 in which the suction lumen 21 is formed, as shown in FIG. 15. This is because by disposing the expansion member 3 on the outer peripheral surface of the second catheter 2 in which the suction lumen 21 is formed, the opening diameter and cross-sectional area of the suction lumen 21 can be increased. Increasing the opening diameter and cross-sectional area of the suction lumen 21 makes it possible to aspirate larger thrombi.

If the expansion member 3 is not embedded in the wall of the second catheter 2, it is preferable to remove corners from the end of the wire 30 by chamfering or the like. This reduces the risk of damaging the inner wall of the device lumen 11 or blood vessels due to contact, such as rubbing, with the end of the wire 30. One example of removing corners is to round the end of the wire 30.

In addition, if the expansion member 3 is not embedded in the wall of the second catheter 2, it is advisable to form the side of the wire 30 to be smooth. This reduces the risk of damaging the inner wall of the device lumen 11 or blood vessels due to contact such as rubbing with the side of the wire 30. One example of a case where the side is smooth is when the cross section of the wire 30 perpendicular to the extension direction is a circle such as an oval or ellipse, or a rectangle with chamfered corners. Figure 15 shows an example where the cross section of the wire 30 perpendicular to the extension direction is an oval.

(4) In the above embodiment, the device lumen 11, wire lumen 12, and inflation lumen 13 are formed in the first catheter 1 as through holes along the axial direction. However, the wire lumen 12 and inflation lumen 13 can also be formed as the internal space of a tube arranged in the device lumen 11 or arranged along the first catheter 1. When forming the wire lumen 12 and inflation lumen 13 as the internal space of a tube, it is preferable to form them as the internal space of a tube arranged along the first catheter 1. This makes it possible to enlarge the internal space of the device lumen 11. This makes it possible to increase the diameter of the suction lumen 21 by, for example, thickening the second catheter 2, thereby making it easier to aspirate thrombi.

(5) In the above embodiment, the expansion member 3 is self-expandable, and its diameter expands due to the restoring force of its own spring elasticity. However, the expansion member 3 is not limited to being self-expandable. The expansion member 3 may be expandable by the supply of power from an external source, for example, via the hub 6. For example, the wire 30 is connected via a joint portion to form the expansion member 3, and a balloon that can be expanded by the supply of a fluid or the like is placed inside the tube of the expansion member 3. The expansion member 3 may then be expanded by pushing the balloon out from the inside of the tube. Note that the balloon may be deflated after the expansion member 3 is expanded.

(6) In the above embodiment, it has been described that the expansion member 3 is supported at the tip of the second catheter 2 and can move axially through the device lumen 11. It has also been described that the device 100 expands the expansion member 3 by protruding the expansion member 3 from the distal opening of the device lumen 11 of the first catheter 1, captures a thrombus with the expansion member 3, and then receives the expansion member 3 with the captured thrombus back into the device lumen 11, thereby removing the thrombus from the blood vessel. However, it is not necessary for the expansion member 3 to be supported at the tip of the second catheter 2. In other words, the second catheter 2 is not essential to the device 100, and it is sufficient that the device 100 has the expansion member 3.

The configurations disclosed in the above embodiment (including other embodiments, the same applies below) can be applied in combination with configurations disclosed in other embodiments, provided no contradictions arise. Furthermore, the embodiments disclosed in this specification are merely examples, and the present invention is not limited to these embodiments. Appropriate modifications can be made without departing from the scope of the present invention.

The present invention can be applied to balloon catheters.

1: First catheter 2: Second catheter 3: Expansion member 5: Expandable portion 9: Blood vessel 11: Device lumen 12: Wire lumen 13: Inflation lumen 15: Thin-walled portion 21: Suction lumen 23: Expansion portion 30: Wire rod 81: First destruction device 82: Second destruction device 91: Thrombus 100: Device (thrombus removal device)
B: Balloon H: Hub (catheter hub)
M: Marker S: Suction device

Claims (6)

a first catheter having an axially extending device lumen;
a second catheter having a suction lumen formed along the axial direction and inserted into the device lumen;
an expansion member that is movable through the device lumen, protrudes from a distal opening of the device lumen, and expands outward in a radial direction of the first catheter to become in an expanded state capable of capturing a thrombus;
A first destruction device that can be inserted into the suction lumen and that applies a physical stimulus to the thrombus to destroy it;
Equipped with
the first catheter has a stretchable portion having circumferential stretchability at a distal end portion where the distal opening is formed,
When the expansion member in the expanded state is received in the device lumen through the distal opening, the distal opening can be expanded by the expansion of the telescopic portion ;
The second catheter
supporting the expansion member at a distal end;
a device lumen movable in the axial direction;
A thrombus removal device in which a suction device is connected to the proximal end of the second catheter, the suction device sucking the thrombus captured by the expansion member proximally by suction within the suction lumen . The thrombus removal device of claim 1 , further comprising a second disruption device positionable outside the second catheter within the device lumen to apply a physical stimulus to the second catheter to disrupt the thrombus. The thrombus removal device according to claim 1 or 2, further comprising a balloon provided at a distal end of the first catheter and expandable by supplying a fluid thereto. 4. The thrombus removal device according to claim 1, wherein a thin- walled portion extending along the axial direction and having a smaller thickness than a proximal end portion of the first catheter is formed at the distal end portion of the first catheter, and the stretchable portion is located at the thin -walled portion. 5. The thrombus removal device according to claim 1, wherein the stretchable portion occupies a range of 50% to 80% of the circumference at the distal end of the first catheter when the stretchable portion is in a contracted state . The thrombus removal device according to claim 1 , wherein the length of the expandable portion in the axial direction is longer than the length of the expansion member in the axial direction.

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