JP7019329B2 - Suction catheter - Google Patents

Description

The present invention relates to a suction catheter.

Conventionally, a treatment method of sucking and removing a thrombus is effective as a treatment method when a stenosis or occlusion occurs in a blood vessel such as a blood vessel or when the blood vessel is obstructed by a thrombus. The catheter used for such treatment is called a suction catheter.

In treatment using a suction catheter, a guide wire is used to guide the suction catheter to the vicinity of the suction target site in the blood vessel. The suction catheter usually has a suction lumen having a suction port for sucking the suction target and a guide wire lumen for inserting a guide wire. Therefore, when inserting the suction catheter into the blood vessel and guiding it to the suction target site in the blood vessel, the surgeon first inserts the guide wire into the blood vessel and the distal end portion of the guide wire is the suction target site. Hold in a blood clot. This secures a guide wire path for the suction catheter to reach the suction target site. Then, the hand side of the guide wire is passed through the tip side of the guide wire lumen of the suction catheter, and the suction catheter is inserted into the blood vessel. The suction catheter is moved in the blood vessel along the guide wire to reach the suction target site, and the thrombus is sucked from the suction lumen. Therefore, the suction catheter is required to have reachability to the lesion site where the foreign substance to be sucked is present and suction performance to suck as much as possible of the object.

Examples of the conventional suction catheter include the suction catheter described in Patent Document 1. The suction catheter described in Patent Document 1 is provided with an opening for sucking a foreign substance such as a thrombus on the tip slope having a slanted tip. A foreign matter cutting means that is movable in the axial direction of the suction catheter is provided so as to partially expose from the opening.

Japanese Unexamined Patent Publication No. 2010-22566

Here, when the outer diameter of the suction catheter is increased and the size of the suction port is increased, the suction performance of the suction catheter is increased, but it is difficult to insert the suction catheter into a peripheral portion consisting of a small blood vessel. Therefore, from the viewpoint of peripheral reachability, there is a limit to increasing the outer diameter of the suction catheter.

Further, in a suction catheter having excellent peripheral reachability, it is difficult to remove a huge thrombus in a peripheral blood vessel because the inner diameter of the suction port or the suction lumen is relatively small. In addition, blood clots are high in fiber. Therefore, a relatively large thrombus may be sucked from the suction port by being dragged by the fiber. Further, such a large thrombus tends to cause obstruction of the suction lumen, and there is a problem that the suction work by the suction catheter takes a long time.

In the suction catheter described in Patent Document 1, the foreign matter cutting means has a cutting portion exposed from the opening and a power receiving portion for driving the cutting portion by receiving power from the outside, and has a structure. It's getting complicated. Therefore, it is difficult to reduce the size of the suction catheter in order to achieve peripheral reachability.

One aspect of the present invention is to realize a suction catheter having excellent peripheral reachability and capable of suppressing obstruction of a suction lumen by a sucked foreign substance.

In order to solve the above problems, the suction catheter according to one aspect of the present invention includes a suction tube having a suction lumen having a suction portion at the distal end, and the suction portion is provided with respect to the axis of the suction tube. A suction catheter having a suction port formed in an inclined manner, wherein a protrusion is provided on the inner wall of the suction lumen, and the protrusion is the most proximal of the suction portion on the inner wall forming the suction lumen. It is characterized in that it is provided on the distal end side of the most recent end region, which is the end side region.

According to one aspect of the present invention, it is possible to obtain an effect that the suction lumen is excellently reachable to the periphery and the suction lumen is suppressed by the sucked foreign matter.

A schematic configuration of a suction catheter which is a premise of the embodiment of the present invention is shown, (a) is a side view, and (b) is a sectional view taken along the line AA. (A) is a cross-sectional view showing a schematic configuration of the distal end side of the suction catheter according to the first embodiment. (B) is a front view showing a schematic configuration seen from the distal end side of the suction catheter according to the first embodiment. It is a figure which showed typically the setting of the occupied area of the protrusion 4 with respect to a suction catheter in the cross section perpendicular to the axis of a suction tube. It is sectional drawing which shows the schematic structure of the distal end side of the suction catheter which concerns on Embodiment 2.

(Structure of suction catheter as a premise of this embodiment)
First, the configuration of the suction catheter that is the premise of this embodiment will be described. 1A and 1B show a schematic configuration of a suction catheter 11 which is a premise of this embodiment, FIG. 1A is a side view, and FIG. 1B is a cross-sectional view.

As shown in FIG. 1 (a), the suction catheter 11 includes a suction tube 1 constituting a suction lumen and a guide wire tube 2 constituting a guide wire lumen. A suction portion 3 is provided at the distal end of the suction tube 1. The suction unit 3 has a suction port 3a for sucking a suction target such as a thrombus. The suction port 3a is provided so as to be inclined with respect to the axis of the suction tube 1. Here, the suction target side of the suction catheter is the distal end side or the distal side, and the opposite side is the proximal end side or the proximal side.

The guide wire tube 2 is provided on the suction portion 3 side of the suction tube 1. Further, the distal end of the guide wire tube 2 is located distal to the position on the most distal end side of the suction portion 3 (the most distal end position 1a shown in FIG. 2). The length of the guide wire tube 2 is, for example, 120 mm.

Further, as shown in FIG. 1B, the wall portion of the suction tube 1 has a laminated structure including an inner layer 12, a reinforcing layer 13, and a covering layer 14. Fluorine-based resin or high-density polyethylene is used as the resin constituting the inner layer 12. Specific examples of the resin constituting the inner layer 12 include polytetrafluoroethylene (PTFE), tetrafluoroethylene / perfluoroalkyl vinyl ether copolymer (PFA), tetrafluoroethylene / hexafluoropropylene copolymer (FEP), and tetra. Examples thereof include fluoroethylene / ethylene copolymer (ETFE), polyvinylidene fluoride (PVDF), polychlorotrifluoroethylene (PCTFE) and the like.

Further, the reinforcing layer 13 has a braided shape in which strands are alternately knitted in a mesh shape. Examples of the material of the wire of the reinforcing layer 13 include synthetic fibers such as nylon fibers and metals such as Ti—Ni and stainless steel.

The covering layer 14 is a layer that covers the inner layer 12 and the braided reinforcing layer 13. An elastomer is used as the resin constituting the coating layer 14. Specific examples of the resin constituting the coating layer 14 include polyamide elastomers, polyester elastomers, and polyolefin elastomers.

[Embodiment 1]
Hereinafter, embodiments of the present invention will be described in detail.

The suction catheter according to the present embodiment is characterized by the structure on the distal end side of the suction catheter 11 shown in FIG. FIG. 2A is a cross-sectional view showing a schematic configuration of the distal end side of the suction catheter 10 according to the present embodiment. FIG. 2B is a front view showing a schematic configuration seen from the distal end side of the suction catheter 10 according to the present embodiment.

In the suction catheter 10, the suction portion 3 has a suction port 3a formed so as to be inclined with respect to the axis X of the suction tube 1. Therefore, the distal end position 1a on the most distal end side and the nearest end position 1b'on the most proximal end side are present at the distal end side of the suction portion 3. Since the guide wire is often arranged along the blood vessel wall in the blood vessel, the distalmost end position 1a adjacent to the guide wire tube 2 is arranged most on the blood vessel wall side in the suction port 3a. On the other hand, the nearest end position 1b'is arranged at the position farthest from the blood vessel wall.

Further, here, with respect to the axis X of the suction tube 1, the side at the most distal end position 1a in the suction portion 3 is the upper side (first side), and the side opposite to the upper side is the lower side (second side). It can be said that the upper side is the side of the suction catheter 10 provided with the guide wire tube 2. The side opposite to the guide wire tube 2 can be said to be the lower side. Further, in the inner wall forming the suction lumen A (hereinafter, may be simply referred to as the inner wall of the suction lumen A), the upper region is referred to as an upper side wall 1c and the lower region is referred to as a lower side wall 1d.

The shape of the most distal end position 1a in the suction portion 3 is a shape inclined downward toward the nearest end position 1b'. Further, the shape of the nearest end position 1b'in the suction portion 3 is a shape inclined upward toward the most distal end position 1a. Assuming that the portion of the distal end position 1a is the nose, the nearest end position 1b'can be regarded as the jaw.

As shown in FIGS. 2A and 2B, the suction catheter 10 according to the present embodiment is provided with a protrusion 4 on the inner wall of the suction lumen A in the suction tube 1. The protrusion 4 is provided on the inner wall of the suction lumen A on the distal end side of the most proximal end region 1b of the suction portion 3. The term "recent end region 1b" as used herein refers to the inner wall region of the suction lumen A from the nearest end position 1b'to the proximal end side in the suction portion 3 to 2 mm.

As a result of diligent studies, the inventor of the present application has found that in the suction catheter 10 provided with the suction port 3a inclined with respect to the axis X of the suction tube 1 as shown in FIG. We have found that the suction pressure in the most recent end region 1b at the suction port 3a is the highest, and the suction pressure decreases toward the distal end side from the most recent end region 1b. Then, based on this finding, the configuration of the suction catheter 10 according to the present embodiment was reached.

According to the suction catheter 10, the protrusion 4 is provided on the inner wall of the suction lumen A on the distal end side of the most recent end region 1b. That is, in the suction lumen A, the protrusion 4 is provided in the region where the suction pressure is relatively low in the suction portion 3, while the protrusion 4 is not provided in the region where the suction pressure is relatively high.

Therefore, for example, when a thrombus having the same size as the suction port 3a and having a large amount of fibrous material is sucked into the suction port 3a, the thrombus sucked into the region where the suction pressure is relatively low comes into contact with the protrusion 4. As a result, the movement toward the proximal end side is locked, so that the suction force applied to the thrombus is reduced. On the other hand, the thrombus sucked into the region where the suction pressure is relatively high is sucked to the proximal end side without abuting on the protrusion 4, so that the suction force applied to the thrombus is high. As described above, in the thrombus, the difference in suction force between the portion that abuts on the protrusion 4 and the portion that does not abut on the protrusion 4 becomes significantly large. Therefore, the thrombus is divided into small sizes by the suction unit 3 and sucked into the suction lumen A. As a result, according to the configuration of the suction catheter 10, the thrombus can be divided into small sizes and sucked into the suction lumen A, so that the suction lumen A is less likely to be blocked by the thrombus.

Further, as described above, the suction catheter 10 has a simple configuration in which the protrusion 4 is provided on the wall of the suction lumen A, so that the suction lumen A is suppressed from being blocked by the thrombus. Therefore, it is possible to reduce the size of the suction catheter 10 in order to realize peripheral reachability while suppressing the obstruction of the suction lumen A due to the thrombus.

As described above, according to the configuration of the suction catheter 10, it is possible to have excellent peripheral reachability and to suppress obstruction of the suction lumen A by a sucked foreign substance.

Further, even if the protrusion 4 is provided in the upper region of the inner wall forming the suction lumen A, that is, in the upper side wall 1c, it is possible to suppress the obstruction of the suction lumen A by the thrombus.

Further, it is preferable that the protrusion 4 is smoothly connected to the surface of the upper side wall 1c of the suction lumen A. That is, it is preferable that the protrusion 4 has a shape that smoothly rises from the upper side wall 1c of the suction lumen A. Here, "smoothly connected to the surface of the upper side wall 1c" means connecting so as to form a continuous curved surface without forming a step with the surface of the upper side wall 1c.

Further, it is preferable that a plurality of protrusions 4 are provided. As a result, the thrombus sucked from the suction port 3a has an increased chance of coming into contact with the protrusion 4. This makes it possible to more reliably divide the thrombus into smaller sizes. When a plurality of protrusions 4 are provided, the plurality of protrusions 4 are provided apart from each other in a direction perpendicular to the axis X of the suction tube 1 as shown in FIG. 2B. Is preferable. Therefore, the thrombus that comes into contact with the plurality of protrusions 4 is subjected to suction force by the suction pressure generated in the gap portion between the protrusions 4, and is divided or compressed. The protrusion 4 is not limited to the configuration shown in FIG. 2 (b) in which two protrusions 4 are provided, and three or more protrusions 4 may be provided. Further, one protrusion 4 may be provided.

FIG. 3 is a diagram schematically showing the setting of the occupied area of the protrusion 4 with respect to the suction catheter 11 in the cross section perpendicular to the axis X of the suction tube 1. If the occupied area of the protrusion 4 is set as described later, it is possible to suppress the obstruction of the suction lumen A by the thrombus.

First, the allowable maximum occupied area of the protrusion 4 with respect to the suction lumen A will be described. The maximum allowable area occupied here means the maximum allowable area of the protrusion 4 occupied in the suction lumen A in the cross section perpendicular to the axis X.

As shown in FIG. 3, the allowable maximum occupied area S _b (max), S (max), and S _a (max) of the protrusion 4 are set to be different depending on the position 1x of the protrusion 4. .. The allowable maximum occupied area S _b (max) of the protrusion 4 when provided in the nearest end region 1 b is 1/2 (that is, 50%) of the area S ₁ of the suction lumen A. The area S1 of the suction lumen _A is the area of the area surrounded by the wall constituting the suction lumen A in the cross section perpendicular to the axis X. The protrusion 4 is provided in, for example, the upper side wall 1c of the nearest end region 1b within a range not exceeding the allowable maximum occupied area _Sb (max). For example, the height of the protrusion 4 (the dimension protruding from the inner wall of the suction lumen A) is set within a range not exceeding 50% of the distance between the upper side wall 1c and the lower side wall 1d. When the suction lumen A is formed in a cylindrical shape, the height of the protrusion 4 is set within a range not exceeding 50% of the diameter of the suction lumen A.

Further, in the region on the distal end side from the most recent end region 1b, the allowable maximum occupied area S (max) of the protrusion 4 is larger than the allowable maximum occupied area S _b (max) and is far from the most recently positioned region 1b. The protrusion 4 increases in proportion to the position 1x provided toward the position end. The position 1x where the protrusion 4 is provided here is a position when the position O shown in FIG. 3 is the origin. It can be said that the position O is the intersection of the vertical line of the upper side wall 1c passing through the nearest end position 1b'and the upper side wall 1c. In other words, the permissible maximum occupied area S (max) of the protrusion 4 increases as the position 1x of the protrusion 4 moves away from the most recent end region 1b toward the distal end.

The protrusion 4 is provided in the region from the nearest end region 1b to the distal end side within a range not exceeding the allowable maximum occupied area S (max) set as described above. For example, the height of the protrusion 4 is set to increase in proportion to the position 1x where the protrusion 4 is provided, from the most recent end region 1b toward the distal end.

The permissible maximum occupied area S _a (max) of the protrusion 4 when provided at the most distal end position 1a is smaller than the permissible maximum occupied area S (max), and is ₁₀₀ of the area S1 of the suction lumen A. %. The protrusion 4 is provided at the most distal end position 1a within _a range not exceeding the allowable maximum occupied area Sa (max). For example, the height of the protrusion 4 is set within a range not exceeding 100% of the distance between the upper side wall 1c and the lower side wall 1d.

Next, the allowable minimum occupied area of the protrusion 4 with respect to the suction lumen A will be described. The minimum allowable area occupied here means the minimum allowable area of the protrusion 4 in the suction lumen A in the cross section perpendicular to the axis X.

As shown in FIG. 3, the allowable minimum occupied areas S _b (min), S (min), and S _a (min) of the protrusion 4 are the same depending on the position 1x of the protrusion 4, and the suction lumen. It is one tenth of the area S ₁ of A, that is, 10%. The protrusion 4 is provided in the region from the nearest end region 1b to the most distal end position 1a within a range not smaller than the allowable minimum occupied areas S _b (min), S (min), and S _a (min). Be done. For example, the height of the protrusion 4 is set within a range not smaller than 10% of the distance between the upper side wall 1c and the lower side wall 1d in the region from the nearest end region 1b to the most distal end position 1a.

[Embodiment 2]
Hereinafter, other embodiments of the present invention will be described in detail. FIG. 4 is a cross-sectional view showing a schematic configuration of the distal end side of the suction catheter 10 according to the present embodiment.

The suction catheter 10A according to the present embodiment relates to the first embodiment shown in FIGS. 2A and 2 in that the protrusion 4A is provided on the lower side wall 1d in the nearest end region 1b. It is different from the suction catheter 10.

As described above, the nearest end region 1b is a side wall region of the suction lumen A from the nearest end position 1b'to the proximal end side by 2 mm. Within such a near-end region 1b, the protrusion 4A is not limited to the configuration provided on the upper side wall 1c as shown in FIGS. 2A and 2B, and is formed on the inner wall of the suction lumen A. It suffices if it is provided. In particular, as shown in FIG. 4, it is preferable that the protrusion 4A is provided on the lower side wall 1d near the nearest end position 1b'.

As a result, the thrombus becomes smaller in size due to the compression effect of the protrusion 4A and is sucked into the suction lumen A. Therefore, according to the configuration of the suction catheter 10A, the suction lumen A is less likely to be blocked by the thrombus.

The suction catheters 10 and 10A according to the first and second embodiments can be manufactured by, for example, a manufacturing method including the following steps (1) to (3). Step (1) The suction tube material to be the suction tube 1 and the guide wire tube material to be the guide wire tube 2 are welded by a conventionally known manufacturing method. Step (2) For this welded body, the distal end portion of the welded body is excised so that at least the opening on the distal end side of the suction tube material becomes the inclined suction port 3a. Step (3) A member to be a protrusion 4 is adhered to a cavity (corresponding to suction lumen A) near the opening (suction port 3a) on the distal end side of the suction tube material.

〔summary〕
The suction catheter 10 according to an embodiment of the present invention includes a suction tube 1 provided with a suction lumen A having a suction portion 3 at the distal end, and the suction portion 3 is inclined with respect to the axis X of the suction tube 1. A suction catheter 10 having a suction port 3a formed therein, wherein a protrusion 4 is provided on the inner wall of the suction lumen A, and the protrusion 4 is the most proximal of the suction portion 3 on the inner wall forming the suction lumen A. It is characterized in that it is provided on the distal end side of the nearest end region 1b, which is an end side region.

Here, in the suction catheter 10 having the suction port 3a formed in the suction portion 3 so as to be inclined with respect to the axis X of the suction tube 1, the distribution of the suction pressure is in the region on the most proximal end side in the suction portion 3. The suction pressure in a certain recent end region 1b is the highest, and the suction pressure becomes smaller toward the distal end side from the nearest end region 1b. According to the above configuration, the protrusion 4 is provided on the inner wall forming the suction lumen A on the distal end side of the nearest end region 1b, which is the region on the most proximal end side of the suction portion 3. Therefore, the protrusion 4 is provided in the region where the suction pressure is relatively low in the suction portion 3, while the protrusion 4 is not provided in the region where the suction pressure is relatively high. For example, when a thrombus having a large amount of fiber of the same size as the suction port 3a is sucked into the suction port 3a, the thrombus sucked in the region where the suction pressure is relatively low abuts on the protrusion and moves to the proximal end side. Is locked, so a relatively low suction force is applied. On the other hand, the thrombus sucked in the region where the suction pressure is relatively high is sucked to the proximal end side without contacting the protrusion, so that a relatively high suction force is applied. As described above, in the thrombus, the difference in suction force between the portion where the protrusion 4 abuts and the portion where the protrusion 4 does not abut becomes significantly large, so that the thrombus is divided into smaller sizes by the suction portion 3. It will be sucked into the suction lumen A. As a result, according to the above configuration, since the thrombus can be divided into small sizes and sucked into the suction lumen, it is possible to realize a suction catheter in which the suction lumen is less likely to be blocked by the thrombus.

Further, according to the above configuration, the simple configuration in which the protrusion 4 is provided on the wall forming the suction lumen A suppresses the obstruction of the suction lumen A by the thrombus. Therefore, it is possible to reduce the size of the suction catheter 10 in order to realize peripheral reachability while suppressing the obstruction of the suction lumen A due to the thrombus.

Therefore, according to the above configuration, it is possible to have excellent peripheral reachability and suppress the obstruction of the suction lumen A by the sucked foreign matter.

Further, in the suction catheter 10 according to the embodiment of the present invention, the most distal end position 1a side of the suction portion 3 is set as the upper side (first side) with respect to the axis X of the suction tube 1. When the side opposite to the upper side (first side) is the lower side (second side), the protrusion 4 is formed on the upper side (first side) region of the inner wall forming the suction lumen A, that is, the upper side wall 1c. It is preferable that it is provided.

As in the above configuration, even if the protrusion 4 is provided in the upper (first side) region of the inner wall forming the suction lumen A, it is possible to suppress the obstruction of the suction lumen A by the thrombus.

Further, in the suction catheter 10 according to the embodiment of the present invention, the allowable maximum occupied area S _b (max), S (max), and S of the protrusion 4 with respect to the suction lumen A in the cross section perpendicular to the axis X. _a (max) increases in proportion to the position 1x where the protrusion 4 is provided from the latest position region 1b toward the distal end, and the maximum allowable area occupied when the protrusion 4 is provided in the latest position region 1b. S _b (max) is 50% of the area S ₁ of the suction lumen A, and is the allowable maximum occupied area S _a (max) when provided at the most distal end position 1 a on the most distal end side of the suction portion 3. ) Is preferably ₁₀₀ % of the area S1 of the suction lumen.

If the occupied area of the protrusion 4 is set within the range satisfying the allowable maximum occupied area S _b (max), S (max), and _Sa (max) as in the above configuration, the suction lumen A by the thrombus is set. It is possible to suppress the blockage of.

Further, in the suction catheter 10 according to the embodiment of the present invention, the allowable minimum occupied areas S _b (min), S (min), and S _a of the protrusion 4 with respect to the suction lumen A in the cross section perpendicular to the axis X. (Min) is ₁₀ % of the area S1 of the suction lumen.

If the occupied area of the protrusion 4 is set within the range satisfying the allowable minimum occupied area S _b (min), S (min), and S _a (min) as in the above configuration, the suction lumen A by the thrombus is set. It is possible to suppress the blockage of.

Further, in the suction catheter 10 according to the embodiment of the present invention, it is preferable that a plurality of protrusions 4 are provided. As a result, the thrombus sucked from the suction port 3a has an increased chance of coming into contact with the protrusion 4.

In the suction catheter 10 according to the embodiment of the present invention, when a plurality of protrusions 4 are provided, the plurality of protrusions 4 are provided apart from each other in the direction perpendicular to the axis X of the suction tube 1. It is preferable to have.

According to the above configuration, the thrombus that comes into contact with the plurality of protrusions 4 is subjected to suction force by the suction pressure generated in the gap portion between the protrusions 4, and is divided or compressed.

The present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the claims, and the embodiments obtained by appropriately combining the technical means disclosed in the different embodiments. Is also included in the technical scope of the present invention.

1 Suction tube 1a Most distal end position 1b Nearest end area 1b'Recent end position 1c Upper side wall 1d Lower side wall 1x position 2 Guide wire tube 3 Suction part 3a Suction port 4, 4A Protrusion part 10, 10A Suction catheter A Suction Lumen S ₁ Area S _a (max), S _b (max), S (max) Allowable maximum occupied area S _a (min), S _b (min), S (min) Allowable minimum occupied area

Claims (6)

With a suction tube with a suction lumen with a suction part at the distal end,
The suction portion is a suction catheter having a suction port formed so as to be inclined with respect to the axis of the suction tube.
The inner wall of the suction lumen is provided with a protrusion for contacting the thrombus and reducing its size .
A suction catheter characterized in that the protrusion is provided on the inner wall forming the suction lumen on the distal end side of the most proximal end region of the suction portion, which is the distal end region. When the distal end position side of the most distal end side of the suction portion is the first side and the side opposite to the first side is the second side with respect to the axis of the suction tube.
The suction catheter according to claim 1, wherein the protrusion is provided in a region on the first side of the inner wall forming the suction lumen. The maximum allowable area occupied by the protrusion with respect to the suction lumen in a cross section perpendicular to the axis increases in proportion to the position where the protrusion is provided from the most recently positioned region to the distal end. death,
The permissible maximum occupied area when provided in the most recent end region is 50% of the area of the suction lumen.
The invention according to claim 1 or 2, wherein the allowable maximum occupied area when provided at the most distal end position on the most distal end side of the suction portion is 100% of the area of the suction lumen. Suction catheter. The invention according to any one of claims 1 to 3, wherein the allowable minimum occupied area of the protrusion with respect to the suction lumen in the cross section perpendicular to the axis is 10% of the area of the suction lumen. Suction catheter. The suction catheter according to any one of claims 1 to 4, wherein the protrusions are provided in a plurality of portions. The suction catheter according to claim 5, wherein the plurality of protrusions are provided apart from each other in a direction perpendicular to the axis of the suction tube.

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